Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

<title>Abstract</title>In this paper, a novel terrain traversability prediction method is proposed for new operation environments. When an off-road vehicle is operated on rough terrains or slopes made up of unconsolidated materials, it is crucial to accurately predict terrain traversability to ensure efficient operations and avoid critical mobility risks. However, the prediction of traversability in new environments is challenging, especially for possibly risky terrains, because the traverse data available for such terrains is either limited or non-existent. To address this limitation, this study proposes an adaptive terrain traversability prediction method based on multi-source transfer Gaussian process regression. The proposed method utilizes the limited data available on low-risk terrains of the target environment to enhance the prediction accuracy on untraversed, possibly higher-risk terrains by leveraging past traverse experiences on multiple types of terrain surface. The effectiveness of the proposed method is demonstrated in scenarios where vehicle slippage and power consumption are predicted using a dataset of various terrain surfaces and geometries. In addition to predicting terrain traversability as continuous values, the utility of the proposed method is demonstrated in binary risk level classification of yet to be traversed steep terrains from limited data on safer terrains.

DOI： 10.1186/s40648-021-00215-3

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Other Link： https://link.springer.com/article/10.1186/s40648-021-00215-3/fulltext.html

Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Publishing type：Research paper (scientific journal)   Publisher：Japan Society for Aeronautical and Space Sciences  

DOI： 10.2322/tastj.19.211

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/lra.2020.3016285

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Robotics Society of Japan  

DOI： 10.7210/jrsj.38.754

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Authorship：Last author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Robotics Society of Japan  

DOI： 10.7210/jrsj.38.54

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Authorship：Last author   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/LRA.2019.2926222

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1299/mej.19-00053

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Authorship：Last author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Robotics Society of Japan  

DOI： 10.7210/jrsj.37.639

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Authorship：Last author   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Mechanical Engineers  

DOI： 10.1299/transjsme.18-00084

J-GLOBAL

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.20965/jrm.2017.p0847

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Publishing type：Research paper (scientific journal)  

DOI： 10.20965/jrm.2017.p0895

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Language：Japanese  

DOI： 10.7210/jrsj.35.230

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/LRA.2016.2525040

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Authorship：Last author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Mechanical Engineers  

This paper presents a novel algorithm that estimates energy consumption of exploration robots for the efficient mobility in natural terrain. The energy estimation method is beneficial to the energy management problem to establish the robot autonomy, especially in energy-limited environments such as planetary surfaces and isolated volcanoes. The key idea of the proposed approach is to employ the terrain classification into the dynamics-based energy estimation model, so that it can adapt to the variability of terrain properties. A vibration-based terrain classifier is proposed in this paper, which analyzes vibration signals in the time-frequency domain and learns terrain patterns by a supervised learning technique. The terrain classification results are used to determine terrain-dependent parameters in the energy estimation model. A field test has been conducted in a volcanic field to show the validity of the proposed algorithm. The proposed method successfully demonstrates the capability to estimate energy consumption, while it raises discussions about determining terrain types in real natural terrain.

DOI： 10.1299/transjsme.15-00399

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Authorship：Last author   Publishing type：Part of collection (book)   Publisher：Springer International Publishing  

DOI： 10.1007/978-3-319-27702-8_25

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Language：English   Publisher：THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES  

&lt;p&gt;We are planning to explore the caverns through the skylight holes on the Moon and Mars. The holes and their associated subsurface caverns are among the most important future exploration targets. The importance of the lunar and Martian holes and their associated caverns is categorized from two aspects: (1) fresh materials are easily observed and sampled there, and (2) the subsurface caverns provide a safe, quiet environment. The expectation of lunar and Martian hole and cavern exploration is increasing in Japan. We name the project as UZUME (Unprecedented Zipangu (Japan) Underworld of the Moon Exploration) whose name is after a Japanese mythology. The ultimate purpose of the UZUME project is to investigate how to expand human activity and survival in space and on extraterrestrial bodies.&lt;i&gt;&lt;b&gt; &lt;/b&gt;&lt;/i&gt;&lt;/p&gt;

DOI： 10.2322/tastj.14.Pk_147

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Authorship：Last author   Language：English   Publisher：The Society of Instrument and Control Engineers  

Recently, planetary investigations have accumulated basic data through various aerospace explorations. However, the investigations of underground such as moonquakes, heat, and conditions of the soil have not revealed much. Therefore, the authors have developed a novel, small planetary subsurface excavation robot that uses the peristaltic crawling of an earthworm as its underground propulsion method. In this study, the authors focused on two types of geotechnical tests: pressure meter and shearing tests using the excavation robot. These tests were conducted by measuring displacement and force in the radial and vertical directions inside the soil, using the excavation robot&#039;s own hardware system. This paper describes these geotechnical tests, which used the propulsion unit of the robot and measured the soil parameters, e.g., internal friction angle, adhesibility, and elastic constant. From the experiments, the authors evaluated and discussed results by comparing with reference data. The authors confirmed that the propulsion unit could measure the soil parameters and propel itself underground at the same time.

DOI： 10.9746/jcmsi.8.242

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Authorship：Last author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Mechanical Engineers  

Soft soils cover on planetary surfaces, so the wheels for exploration rovers easily slip. Understanding an interaction between a wheel and soft soils is important for a traction control to improve rover traversability. The interaction between the wheel and soft soils has been studied in a field of terramechanics. Since the classical terramechanics-based wheel model considers only a static state of a wheel sinkage, the wheel model is not applicable to the wheel sinkage and slip. Thus the dynamic normal stress model and shear deformation model were proposed to deal with the problems of the wheel sinkage and the slip. The dynamic normal stress model was proposed by considering the wheel sinking velocity and a variation of soil state for solving the problem of wheel sinkage. And the shear deformation model was proposed by considering the shear characteristics for solving the problem of wheel slip. The shear deformation model was formulated by the shear test. The simulation verified the validity of the dynamic normal stress model and the shear deformation model in the transient state. In this paper, a single wheel experiments was performed to evaluate the shear deformation model by comparing the simulation results and the experimental results. Then the characteristics of the wheel sinkage and slip and the effectiveness of the model were confirmed.

DOI： 10.1299/transjsme.14-00514

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Language：English   Publishing type：Research paper (scientific journal)  

Web of Science

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1007/978-3-319-07488-7_25

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer International Publishing  

DOI： 10.1186/s40648-014-0015-6

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Asian Electric Vehicle Society  

In recent years, to cope with low carbon society and diversification of individual mobility, new kinds of vehicles have received a lot of attention to expand our mobility. This paper proposes a new concept of vehicle named portable personal vehicle. The proposed portable personal vehicle is small and light enough, which enables not only to carry the driver but also to be carried by the driver. The proposed portable personal vehicle can easily overcome barriers in mixed traffic such as university campus, airports, shopping malls etc. It is harmless to surrounding pedestrians. This paper describes a developed inverted pendulum vehicle based on the concept of portable personal vehicle.

DOI： 10.4130/jaev.12.1693

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Language：English  

DOI： 10.20965/jrm.2014.p0660

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Authorship：Last author   Language：Japanese   Publisher：The Robotics Society of Japan  

As of today, several rovers have been deployed on planetary surfaces and provided astonishing scientific achievements. A significant challenge in future missions is accurate localization for long distances to expand the activity range. After the successful Mars Exploration Rovers mission, visual odometry is regarded as a promising technique to provide accurate pose estimates on planetary surfaces. However, it should address the problem of terrain dependency since it cannot estimate motion in the terrain where visual features are lacked. This paper proposes a visual odometry system for untextured natural terrain which is devoid of features. Several key techniques are presented including a scheme for terrain-adaptive feature detection, and a motion estimation method using fewer feature points. The feasibility of the proposed techniques is supported by the field tests in a volcanic field using a test-bed rover.

DOI： 10.7210/jrsj.32.825

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Other Link： https://jlc.jst.go.jp/DN/JLC/20000646558?from=CiNii

Language：Japanese  

CiNii Research

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Language：Japanese  

CiNii Research

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.5772/57361

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Authorship：Last author   Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1007/978-3-642-40686-7_29

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1080/01691864.2013.843789

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/rob.21462

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Language：Japanese   Publisher：The Society of Instrument and Control Engineers  

Power source and sensing of self position are commonly required for mobile robots. Recently, wireless power transmission and position sensing from the systems embedded in the surrounding space are proposed as effective measures. Since wireless power transmission and position sensing are regarded as totally different functions, they have been realized by independent systems. However, combining multi-function into a single system has various advantages such as cost down and space-saving. Therefore, in order to realize both functions in single system, the authors have researched on position sensor via magnetic resonance coupling which have been used in the wireless power transmission field. However, there were several problems in the prototype system using arrayed transmitter antenna such as, reduction of Q factor due to the increase of wire length, the compensation capacitance values have to be set individually and antenna alignment are fixed. Therefore, as a solution, position sensor using relay antennas via magnetic resonance coupling is proposed in this paper. The novel position sensing method is proposed and evaluated through the position sensing experiment assuming mobile robot as the target.

DOI： 10.9746/sicetr.49.646

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Other Link： https://jlc.jst.go.jp/DN/JALC/10020766046?from=CiNii

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2514/1.58373

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/TMECH.2012.2222429

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Fuji Technology Press  

DOI： 10.20965/jrm.2013.p0466

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DOI： 10.20965/jrm.2012.p1031

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Society of Instrument and Control Engineers  

Developing autonomous mobile robots that can coexist with human in populated environments is still considered a big challenge. To address this problem the authors propose a novel scheme to assist mobile robots by providing localization information externally. This scheme combines the autonomous navigation and target tracking research fields to arrive at a structured assistance system for autonomous mobile robots. In the proposed scheme, the environment is sensed using a laser range finder and a camera based sensor unit. Using the Rao-Blackwellized particle filter technique, the robots that need assistance are continuously tracked. In contrast with conventional laser range finder based tracking systems, the placement of the sensor is changed to a level above average human height and the mobile robots are modified by attaching a cylindrical pole. The experiments showed the validity of the proposed scheme for simultaneous localization assistance for multiple mobile robots. Two mobile robots were simultaneously navigated in given trajectories using assistance data, successfully.

DOI： 10.9746/jcmsi.5.349

CiNii Research

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s12369-011-0104-0

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1541/ieejias.132

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Language：Japanese   Publishing type：Research paper (scientific journal)  

CiNii Research

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.7446/jaesa.0403.01

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.4130/jaev.10.1583

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Language：English   Publisher：Asian Electric Vehicle Society  

This paper presents the effectiveness of the flexible wheels for lunar exploration rovers. The flexible wheels give high performance while traversing loose soil. The flexible wheel is an effective scheme to traverse loose soil without poor performance. The flexible wheel has a surface which can be changed flexibly for rough terrain. When the surface of wheel performs matching the shape of ground it is crossing, the normal stress between the wheel and loose soil becomes small. It is prevented from sinking because this normal stress is small. However, the flexible wheel doesn&#039;t have high performance without grousers. The grouser is very important to get thrust for rovers. From running experiments using a single wheel tester, we found that the flexible wheel with grousers gave a high performance. The mounted positions of grousers on the surface of the wheel are defined by the same angle (ex) 36 deg). This means that there are two patterns to mount grousers. One is under the rib while the other is between the ribs. The spring force under the rib is different from between the ribs, it is greater. Moreover, each distortion is different. From these considerations, we need to find the optimal position for grousers. We carried out running experiments using wheels with both patterns. From our experiments, we understood the wheel with the position mounted between ribs gave a better performance than when it was set under the rib. When the area giving normal stress is wide, soil under the wheel becomes hard. Therefore, the wheel with grousers mounted between ribs gives a higher performance compared with the one mounted under the ribs.

CiNii Research

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1299/kikaic.78.1109

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1541/ieejias.132.437

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Fuji Technology Press  

DOI： 10.20965/jaciii.2012.p0341

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1080/01691864.2012.685227

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Language：English   Publisher：THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES  

Since 2008, a new plan for next Mars exploration program has been proposed and discussed by scientists and engineers in Japan. This exploration program is named MELOS, or Mars Exploration with Lander and Orbiter Synergy, a long-awaited program in the planetary science community in Japan after unsuccessful end of Nozomi Mars orbiter and ongoing challenge of Akatsuki Venus orbiter. The goal of the whole program is to understand Mars as a system, by elucidation of Martian climate, atmospheric escape, internal structure, surface environment and interaction by them. A series of missions has been planned, and several spacecraft including orbiters and landers are under discussion to be launched in early 2020&#039;s. In this paper, we investigate launch opportunities during early 2020&#039;s and estimate the payload mass in each case. Feasible interplanetary transfer trajectories from Earth to Mars are proposed. Preliminary design of insertion sequence into the Mars orbit and some orbit candidates derived from mission requirements are also shown together with numerical simulation results.

DOI： 10.2322/tastj.10.Tk_19

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Language：English   Publisher：Asian Electric Vehicle Society  

Predicting the tractive limitations of locomotion gears is of critical importance in a robotic vehicle system on natural terrain. In particular, it is imperative for an unmanned mobile robot to avoid getting stuck in loose soil to retain its mobility. From this perspective, this paper attempts to theoretically predict the limitations of a typical wheel in such loose soil based on traditional soil-wheel interaction models. In the case that the model brings a negative drawbar pull exerted by the wheel under any kinematic slip condition, we analytically investigated the limitations using a ratio of sinkage over the wheel radius. Predicted limitations are suggested for design optimization and control of the wheeled vehicle. Furthermore, this paper presents the relationship between the model analysis and a practical single wheel test, which provides significant guidelines for usage of the experimental results.

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Language：English   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1299/kikaic.78.2781

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2514/1.53786

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2322/tjsass.54.98

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1163/016918611X563300

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Language：English   Publisher：The Japan Society of Mechanical Engineers  

Execution of scientific objectives such as to investigate the central peaks of a big crater of the moon is thought to be the most scientifically interesting. Precise and safe autonomous landing ability is a productive issue for this investigation. Here it is proposed a scheme of trajectory generation for lunar descent. This research includes a sketch of a qualitative scheme on solutions of motion control equations for lunar descent vehicle from orbital speed condition down to the terminal descent situation. A trajectory generation algorithm is developed accumulating more than one step with variable thrust to mass ratio. Mathematical modeling, algorithm design, simulations and results are presented in this paper. In fact, the proposed trajectory generation scheme can readily be used to develop real-time guidance algorithm for future precise and safe lunar landing missions reducing the computational burden.

DOI： 10.1299/spacee.4.1

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1163/016918611X563355

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Authorship：Last author   Language：Japanese   Publishing type：Research paper (international conference proceedings)   Publisher：Japan Society of Mechanical Engineers  

DOI： 10.1299/kikaic.76.3595

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.icarus.2009.12.035

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DOI： 10.1016/j.icarus.2009.09.002

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Language：English   Publisher：THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES  

In this article, preliminary feasibility assessment of aeroassist systems for JAXA&#039;s future Mars Exploration has been conducted. The aerobraking technology is found to bring about an increase in the payload ratio by considerable reduction of the propellant mass required for orbital descent after propulsive orbital insertion. The aerocapture technology, if accuracy in both the interplanetary orbit determination and guidance is improved, is shown to achieve a remarkable increase of the payload mass using the state-of-the-art technologies. Discussions are made on the guided entry systems which are expected to realize better landing mark precision than obtained by the ballistic flight.

DOI： 10.2322/tastj.8.Pk_23

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1163/016918610X501255

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1163/016918609X12619993300629

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Language：English   Publisher：THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES  

Japan has launched many interplanetary spacecraft for exploration of solar system bodies including Mars. Now we are planning the next Mars mission in the late 2010&#039;s. This paper describes the preliminary mission analysis and orbit design for this plan. The combined exploration by several spacecraft requires complicated and careful consideration, different from those for single-probe missions. Mission plans to realize required configuration by a single launch and simple simulation results are reported.

DOI： 10.2322/tastj.8.Tk_7

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.actaastro.2009.01.074

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Language：Japanese   Publisher：The Robotics Society of Japan  

DOI： 10.7210/jrsj.27.482

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Other Link： https://jlc.jst.go.jp/DN/JALC/00333532025?from=CiNii

Language：Japanese   Publisher：The Robotics Society of Japan  

DOI： 10.7210/jrsj.27.481

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Other Link： https://jlc.jst.go.jp/DN/JALC/00382174429?from=CiNii

Publishing type：Research paper (scientific journal)  

DOI： 10.1299/kikaic.75.2295

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Language：English   Publisher：Asian Electric Vehicle Society  

Lunar rovers are required to traverse rough terrains with craters and sheer cliffs-often seen in locations of scientific importance. Recently, wheeled rovers have been gaining popularity in conducting planetary exploration missions. However, wheeled rovers are likely to get stuck in the soil while traversing such terrains. One way to solve this problem is to use flexible wheels. In this study, experiments were carried out to simulate actual running conditions using flexible wheels. The results showed that flexible wheels had a high level of performance when traversing loose soil on a slope. The experiments were carried out using various flexible wheels that allowed different amounts of deflection. The flexible wheels were made from beryllium copper, magnesium, and stainless steel. In these experiments, we measured slip ratio and sinkage for each of these materials.

DOI： 10.4130/jaev.7.1319

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Language：English   Publisher：Asian Electric Vehicle Society  

Lunar rovers are required to traverse rough terrains that include craters and rear cliffs, which are scientifically important locations that need to be explored. Recently, wheeled rovers have been gaining popularity for their use in conducting planetary exploration missions. However, there is a problem associated with wheeled rovers in that they are likely to get stuck in soil while traversing such terrains. In this study, we develop a new flexible wheel. This wheel can traverse soft soil. We describe an interaction model between the flexible wheel and soft soil. Then, on the basis of this model, we propose new wheel forms. In addition, to determine the traversability of the proposed wheel on the basis of slip ratio and sinkage, we perform running experiments on soil, similar to regolith.

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Language：English   Publishing type：Research paper (international conference proceedings)  

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DOI： 10.1299/kikaic.74.2962

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：University of Arkansas  

DOI： 10.1111/j.1945-5100.2008.tb00692.x

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

Lunar rovers are required to move on rough terrains such as in craters and rear cliffs where it is scientifically very important to explore. In the past, wheel typed rovers are popular for planetary exploration missions. However, there is a problem that the wheel typed rovers have possibility of stack. Therefore, this paper investigates a mechanism of kinetic behavior between the wheels of the exploration rovers and soil. The important parameters are extracted by considering the mechanism. This paper proposes an elastic wheel by considering the important parameters. The elastic wheel has the surface which can be changed flexibly toward rough terrain. Running Experiments on soil which imitated Regolith are carried out to observe the traversability of the elastic wheel using slip ratio and sinkage.

DOI： 10.1299/kikaic.74.2962

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/j.1945-5100.2007.tb00538.x

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DOI： 10.1016/j.asr.2007.04.075

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DOI： 10.1299/kikaic.72.3842

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1126/science.1126574

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DOI： 10.1126/science.1125722

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1126/science.1126272

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After global observations of asteroid 25143 Itokawa by the Hayabusa spacecraft, we selected the smooth terrain of the Muses Sea for two touchdowns carried out on 19 and 25 November 2005 UTC for the first asteroid sample collection with an impact sampling mechanism. Here, we report initial findings about geological features, surface condition, regolith grain size, compositional variation, and constraints on the physical properties of this site by using both scientific and housekeeping data during the descent sequence of the first touchdown. Close-up images revealed the first touchdown site as a regolith field densely filled with size-sorted, millimeter- to centimeter-sized grains.

DOI： 10.1126/science.1126164

PubMed

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CiNii Research

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Language：English   Publisher：Japanese Rocket Society  

The spacecraft Hayabusa performed the descent flights to the target asteroid ltokawa in November of 2005. The surface of ltokawa has a lot of boulders and there are few flat areas where the spacecraft can touch down safely. With the reaction wheels lost prior to the touchdown events, it was very difficult to control translational motion accurately, since the guidance accuracy of several millimeters per second was requested. To accurately determine the spacecraft position, a landmark tracking scheme with the help of the ground operation was introduced and developed in the Hayabusa mission. The Hayahusa project team developed new tools that combined human assist with the computer aided terminal display. The proposed landmark tracking scheme did contribute to the successful precise navigation to the specified area on the surface. This paper presents a descent navigation method with the landmark tracking used for the Hayahusa mission, including the developed ground operation tools.

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Language：English   Publisher：Japanese Rocket Society  

The asteroid exploration spacecraft Hayabusa attempted to touch-down two times in November, 2005. The autonomous guidance and navigation capability is installed aboard the spacecraft, which collects the laser altimeter, laser range finders and navigation cameras information aboard and to estimate where the spacecraft is and to decide the path correction maneuvers toward the asteroid ITOKAWA by itself. The function programmed in Hayabusa includes the image processing designed to detect an artificial target marker location. This paper presents how the touch-down events were carried out by showing the flight results along with the detail of onboard GNC(Guidance, Navigation and Control) system.

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Language：English   Publisher：Japanese Rocket Society  

Hayabusa spacecraft performed a proximity operation including station keeping and hovering around the asteroid (25143) Itokawa from September to November in 2005. In order to navigate and guide the spacecraft to Itokawa, the spacecraft was equipped with sophisticated autonomous navigation and guidance functions including onboard image processing. Since one of three reaction wheels for attitude control failed in late July of 2005 and the second wheel failed in early October, however, the autonomous guidance did not work as designed. To overcome the unexpected anomalies, an optical navigation technique combined with the radiometric information obtained on the ground was used and the proximity operation around the asteroid could be accomplished as planed. This paper presents how those navigation and guidance in proximity phase were carried out, showing with some flight rcsults.

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Language：English   Publisher：Asian Electric Vehicle Society  

In future planetary exploration missions, rovers are required to traverse over very rough terrain. The Moon&#039;s surface is covered with soil which is named regolith. Regolith is easy to slide. A stack occurs to the rovers which are running on the regolith. The cause of the stack is not yet clear. At first, this paper investigates kinematics behavior of lunar rovers with a tire-soil traction mechanism where the condition of the moon is a vacuum. In vacuum condition, experiment of the running is carried out, and, air and vacuum conditions are compared. Finally, this paper considers whether experiment of vacuum is effective on the earth.

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

In future planetary exploration missions, planetary robots are required to traverse over very rough terrain. On the lunar surface, there are covered with soils which are named regolith. Regolith is easy to slide. Any stack is easy to occur to the rovers which are running on the regolith. The mechanism, which occurs stacks, is not yet clear. Therefore, this paper investigates the kinematics behavior of lunar rovers with tire-soil traction mechanism. This traction mechanism shows two important parameters for running wheel on regolith. One is the effect of hardening. And the other is the effect of shearing. New wheel forms are designed by considering these effects. Some experiments using the proposed wheels are performed to observe the performance of traversability. Analysis of experimental results shows that to combine these two effects is effective.

DOI： 10.1299/kikaic.72.3842

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (scientific journal)  

Web of Science

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Language：Japanese   Publisher：計測自動制御学会  

CiNii Research

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Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.14822/kjsass.53.620_276

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Language：Japanese   Publisher：THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES  

This paper proposes a new mobility system for exploration under microgravity by using springs and linear actuators. In a microgravity, it is difficult to obtain horizontal velocity because the friction force between the robot and the ground is very small. By pushing off the ground, however, the robot can not only hop, but also obtain horizontal velocity. The proposed hopping robot consists of three masses and can push off the ground using springs. The robot can hop from the stationary state by transforming the elastic energy to kinetic energy using the springs and linear actuators. The robot can land without bouncing by transforming kinetic energy back to elastic energy. Free fall experiments demonstrate the landing performance of the proposed system.

DOI： 10.2322/jjsass.53.108

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Publisher：The Japan Joint Automatic Control Conference  

This paper deals with kinetic behavior of lunar explorer with tire-soil traction mechanism. Experiments are performed to observe the physical dynamics between soils and wheels. The performance of the mobility is discussed based on experiments by changing some parameters, the velocity, the load and the slope. This paper also studies the traction control scheme for wheeled robot. The effectiveness of the proposed scheme is shown by some experiments.

DOI： 10.11511/jacc.48.0.152.0

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Language：English   Publishing type：Research paper (international conference proceedings)  

Scopus

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Language：Japanese   Publisher：The Robotics Society of Japan  

This paper proposes a new mobility system for planetary exploration robot using springs and linear actuators. In microgravity environment, it is difficult to obtain the horizontal velocity, because the friction force between a robot and the ground is very small. By pushing the ground, however, the robot can not only hop, but also obtain the horizontal velocity. The proposed hopping robot consists of two masses, and can push the ground by using springs. The robot can hop from the stationary state by transforming the elastic energy to the kinetic energy using the sprigs and linear actuators. Furthermore the robot can land without bounding by transforming the kinetic energy to the elastic energy. The simulation studies and the ground experiments show the effectiveness of the proposed mobility system.

DOI： 10.7210/jrsj.21.663

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Other Link： https://jlc.jst.go.jp/DN/JALC/00231394473?from=CiNii

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/S0094-5765(02)00187-X

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Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/s0094-5765(02)00186-8

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1016/S0094-5765(02)00185-6

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Language：English   Publishing type：Research paper (international conference proceedings)  

DOI： 10.1016/S0094-5765(02)00178-9

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/S0273-1177(02)00491-X

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Language：English   Publisher：Japanese Rocket Society  

The authors have studied the mechanism, which achieves the low restitution coefficient under the microgravity environment, and realized that the mechanism which is constructed out of a rigid shell with balls stored internally makes the restitution coefficient small. On impact, the balls will dissipate energy relative to each other and hence will dissipate the total energy. High efficiency in energy dissipation means the low restitution coefficient. In this paper, the relations among the parameters in this mechanism and the restitution coefficient is analyzed numerically, and confirmed through the microgravity tests.

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Language：English   Publishing type：Research paper (scientific journal)  

Web of Science

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DOI： 10.1016/0892-9270(95)00012-7

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DOI： 10.2322/jjsass1969.43.567

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Language：Japanese   Publisher：日本航空宇宙学会  

DOI： 10.2322/jjsass1969.42.692

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/41.170967

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1109/37.126850

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Language：Japanese   Publisher：The Robotics Society of Japan  

This paper describes a control scheme for a robotic manipulator system which uses visual information to position and orientate the end-effector. In the scheme the position and the orientation of the target workpiece with respect to the base frame of the robot are assumed to be unknown, but the desired relative position and orientation of the end-effector to the target workpiece are given in advance. The control system directly integrates visual data into the servoing process without subdi-viding the process into determination of the position and orientation of the workpiece and inverse kinematic calculation. An artificial neural network system is used for determining the change in joint angles required in order to achieve the desired position and orientation. The proposed system can control the robot so that it approach the desired position and orientation from arbitrary initial ones. Simulation for the robotic manipulator with six degrees of freedom is done. The validity and the effectiveness of the proposed control scheme are verified by computer simulations.

DOI： 10.7210/jrsj.8.4_390

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Language：Japanese   Publisher：The Robotics Society of Japan  

This paper describes a local path planning method of a mobile robot to search path in an unknown environment by using visual information. The mobile robot system has a hierarchical path planning system which searches path efficiently in an uncertain environment. The planning system consists of a global planner and a local planner. The global planner gives a global path in termes of a sequence of visual sub-goals. Then the local planner generates a local path between the sub-goals with the help of visual sensor. The main focus of this paper is on the local path planning which provides real-time guidance to the system. Visual sensor can provide useful information about the environment. So an algorithm is proposed to generate avoiding points by using visual information to bypass unknown obstacles in the local path planning. The local path planning in simple environment is simulated by using three dimensional graphics. A simple experiment is also done for the case that there are two obstacles. The validity of the proposed method is verified by these simulations and experimental results.

DOI： 10.7210/jrsj.7.267

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Language：Japanese   Publisher：The Robotics Society of Japan  

This paper describes a navigation method of a mobile robot based on cooperation of sensors. Among various sensors, vision is expected to play a very important role in control of intelligent mobile robot. In this paper firstly a method is presented to guide the robot in real time by using visual sensor. The mobile robot is controlled to follow visual sub-goal by visual feedback. The robot can detect unknown obstacles and make avoiding paths automatically. Obstacle avoidance based on visual information is then simulated. The result of the simulation shows that navigation using only visual information has several problems, because it is impossible to get the environmental information close to the robot by visual sensor. In order to solve those problems, visual sensor and range sensors such as ultra-sonic sensors, are cooperated together. It is important to integrate the information of multiple kinds of sensors. A control method, which utilizes the information fusion between vision and range sensors, is proposed. The validity of the method is verified by simulations and experimental results.

DOI： 10.7210/jrsj.7.275

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Publ by American Soc of Mechanical Engineers (ASME)  

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Japan has decided to launch the second sample return mission "Hayabusa-2" to the Near Earth asteroid 1999JU3 in 2014. The predecessor spacecraft "Hayabusa" made a great success when it returned to the Earth in June 2010 with a capsule containing some particles obtained around the S-type asteroid "Itokawa." The authors installed a tiny hopping rover called "MINERVA" into Hayabusa spacecraft. The rover was deployed at the vicinity of the asteroid in 2005, but failed to make a surface exploration since the human operator on the ground made a critical failure in deploying the rover. The second spacecraft also involves a plan to have a tiny rover system which will make a surface exploration over the 1km-sized asteroid. With the past experience in developing a rover, the authors are again working to install some rover packages to Hayabusa-2. The total concept is the same but this time multiple rovers are considered. Many of the aspects of the mother spacecraft come from the heritage of the previous explorer which was build using the technologies more than ten years ago. But the rover system is a completely brand-new one, based on the lessons learned from the previous rover system. Since the target asteroid parameters are different from the previous target, the rover design has to be made from the beginning. We also face to the another technically challenging matters arisen from the point of the distance from the Sun as well as the surface cruel temperature of low-albedo body. This paper describes the system configuration of the rover system currently designed and developed for the launch in 2014.

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Language：English  

DOI： 10.1109/TMECH.2013.2268162

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Language：English   Publishing type：Research paper, summary (international conference)  

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Language：Japanese   Publisher：Japan Society for Simmulation Technology  

CiNii Research

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CiNii Research

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J-GLOBAL

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CiNii Research

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CiNii Research

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Other Link： http://id.nii.ac.jp/1004/00007742/

Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

CiNii Research

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Language：English  

DOI： 10.1163/016918610X501237

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Language：English   Publisher：Wiley-VCH Verlag GmbH &amp; Co. KGaA  

DOI： 10.1002/9783527626625.ch6

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Language：Japanese   Publisher：The Japanese Society for Planetary Sciences  

CiNii Research

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J-GLOBAL

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Language：Japanese   Publisher：建築保全センター  

CiNii Research

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DOI： 10.14909/jsps.2007f.0.12.0

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DOI： 10.2514/6.2006-6661

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DOI： 10.2514/6.2006-6660

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DOI： 10.2514/6.2006-6539

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CiNii Research

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CiNii Research

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CiNii Research

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DOI： 10.14909/jsps.2005f.0.42.0

J-GLOBAL

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DOI： 10.14909/jsps.2005f.0.41.0

J-GLOBAL

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Language：Japanese   Publisher：The Robotics Society of Japan  

DOI： 10.7210/jrsj.21.494

CiNii Research

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Other Link： https://jlc.jst.go.jp/DN/JALC/00230537734?from=CiNii

Language：Japanese   Publisher：The Robotics Society of Japan  

DOI： 10.7210/jrsj.21.468

CiNii Research

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Other Link： https://jlc.jst.go.jp/DN/JALC/00230537673?from=CiNii

Language：Japanese  

CiNii Research

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Language：Japanese   Publisher：宇宙航空研究開発機構  

M-V型ロケットには,慣性航法誘導装置(ING: Inertial Navigation Guidance)を第3段計器部に搭載し、第1段から第3段までの3軸姿勢制御を行う.M-3SII型ロケットまでの姿勢基準装置は,レートジャイロ(FRIG: Floated Rate Integration Gyro)という機械式ジャイロを1軸のスピンフリーテーブル(SFAP)上に配置していたが,M-V型ロケットにおいては,ファイバオプティックジャイロ(FOG: Fiber Optic Gyro)を機軸に固定するストラップダウン方式を用いて,計算機(CPU)内部で座標変換を行う方式へと大幅に変更をしている.この新しい姿勢基準装置(IMU: Inertial Measurement Unit)は,搭載加速度を用いて,機上で航法誘導演算を行う慣性航法誘導装置INGを構成しているのも,M-V型機の特徴である.FOGは,機械的な可動部分を全くもたないため,信頼性が高く,次世代のジャイロとして諸外国が開発にしのぎを削っているものである.しかしながらその反面,その実用化,特に慣性航法誘導装置に採用されるレベルのドリフト変動を実現するのは非常に困難である.M-V型ロケットで採用しているFOGは,さまざまな課題を克服して完成したものであり,画期的な装置となっている.IMU及びCPUは,第3段の計器部に配置され,この部位での角速度情報は,姿勢変動分のインクリメントとして計測される.一方,第1段の姿勢制御においては,第1段の可動ノズルの応答を加味すると,第3段位置での角速度情報を用いるよりも,第1段後部筒部位での角速度情報を用いた方が、制御系の安定余裕を確保しやすい.そのため,第1後部筒部位には,レートジャイロが搭載されている.第2段ノズル部には,第1段飛翔中の横加速度を測定し,荷重を軽減する論理を可能とすべく,計測用として加速度計が搭載されている.また,各段には通信制御部(I/O)が搭載され,各段間のデータのやりとりを行う.

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Language：Japanese   Publisher：Information Processing Society of Japan (IPSJ)  

In recent years, deep space exploration has a lot of attention in the world. Planetary exploration missions have been earnestly studied in Japan as well as US and Europe. As mission requirements are high-level, such advanced technology as landing or rover exploration is required. Because direct surface exploration could throw the light upon the origin and evolution of the earth-type planets. Image processing is expected to play a very important role in deep space exploration. This paper describes image processing technology in space. This paper also presents image based schemes for global mapping, autonomous landing system, and rover navigation.

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Other Link： http://id.nii.ac.jp/1001/00052656/

Language：English   Publisher：The Japan Society of Mechanical Engineers  

CiNii Research

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Language：Japanese   Publishing type：Book review, literature introduction, etc.   Publisher：Inst. of Image Information and Television Engineers  

DOI： 10.3169/itej.57.1230

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Language：Japanese   Publisher：The Institute of Electrical Engineers of Japan  

DOI： 10.1541/ieejjournal.120.746

CiNii Research

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Other Link： https://jlc.jst.go.jp/DN/JALC/00070220711?from=CiNii

DOI： 10.1541/ieejjournal.120.746

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Language：Japanese   Publisher：The Society of Instrument and Control Engineers  

DOI： 10.11499/sicejl1962.39.570

CiNii Research

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Other Link： https://jlc.jst.go.jp/DN/JALC/00068523787?from=CiNii

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J-GLOBAL

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Language：English  

DOI： 10.1163/156855300741861

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Language：Japanese   Publisher：The Robotics Society of Japan  

DOI： 10.7210/jrsj.18.941

CiNii Research

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Other Link： https://jlc.jst.go.jp/DN/JALC/00069325274?from=CiNii

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Language：Japanese   Publisher：The Robotics Society of Japan  

DOI： 10.7210/jrsj.17.609

CiNii Research

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Other Link： https://jlc.jst.go.jp/DN/JALC/00061598409?from=CiNii

J-GLOBAL

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CiNii Research

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

MUSES-C is a sample return mission program of ISAS toward the asteroid NEREUS. The mission requires innovative guidance and navigation control technology such as interplanetary cruise, approach toward the asteroid, touch-down, and take-off.This paper reports the development of four sensors, star tracker, lidar, laser range finder, fan beam sensor, for guidance and navigation control system of MUSES-C.

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DOI： 10.11230/jsts.12.1_1

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DOI： 10.7210/jrsj.15.986

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Language：English   Publisher：Japanese Rocket Society  

Recently there have been a lot of attention to developing planetary rovers for Lunar or Mars Exploration. In 1997, Mars Pathfinder succeeded in landing Martian surface and the micro-rover &amp;ldquo;sojourner&amp;rdquo; could travel on Mars. Toward the turn of the century, several schemes sending an unmanned mobile explorer to the moon or Mars are being planned for scientific exploration. Planetary rovers are required to travel safely over a long distance for many days in unknown terrain and are also required to explore rough and steep areas such as craters, cliffs, etc. to achieve scientific goals. Most of the proposed rovers have some wheels to move on a planetary surface. However, a legged rover can provide higher capability of moving in such a rough terrain than wheeled robots. Therefore the authors have studied a small and light-weight rover which can move across a rough terrain such as a steep slope inside craters. A prototype of the robot with six legs has been developed. This paper presents the system concept, architecture, and configuration of the developed walking rover for planetary exploration. This paper also discusses a stability criterion and a walking algorithm for static walking in a rough terrain.

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DOI： 10.7210/jrsj.14.940

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DOI： 10.7210/jrsj.14.940

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Event date： 2019.11

Language：English   Presentation type：Oral presentation (keynote)  

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Event date： 2015

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We have been developing a lunar subsurface excavation robot using peristaltic crawling based on an earthworm&#039;s locomotion. In existing robots, the excavated soil must be manually removed by humans. To overcome this limitation, we have been developing a mechanism that automatically removes the excavated soil. This paper presents our new automatic soil-release mechanism and demonstrates the performance of the mechanism using a prototype.

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Event date： 2014.1

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Event date： 2014

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Asteroid probe Hayabusa 2 is developed by JAXA. Asteroid exploration rovers will be carried by Hayabusa 2. In our research project, we have developed an environmental-temperature-driven buckling actuator with a bimetal thin plate for a hopping mechanism of the rover. In this study, to characterize the hopping capability of the actuator, we conducted microgravity examination in ZARM drop tower. We fabricate a test rover for the microgravity examination with a rapid heating system for actuation in short free-fall time. Although reaction force from baseplate was incomplete in take-off, the rover hopped with a vertical velocity of 3.12 mm/s with 0.035 rad/s rotating rate.

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Event date： 2014

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Event date： 2014

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Lunar or planetary exploration is scientifically meaningful because they can give us the hint to throw a light on the origin and evolution of the solar system or the earth, the inner structure of planets, etc. In lunar or planetary exploration missions, it is important to save the weight of spacecraft. Light weight spacecraft leads to low cost and getting more chance to go to the space. Conventionally a lander carries a rover to the surface of the celestial body and the rover traverses the rough terrain to explore in wide region. If the lander and the rover are united, however, the total weight of the spacecraft could be reduced. The authors have already proposed a novel pulley suspension mechanism, which is called Load Equalization Pulley Suspension mechanism: LEPS mechanism, for rovers. The performance of the proposed mechanism as a suspension mechanism of rovers has been evaluated. In this paper, the application of LEPS mechanism to the landing gears of the lander is discussed. By applying the proposed mechanism to the landing gears, the lander can move around the wide region of the surface after landing. The landing dynamics model of the proposed &quot;Movable lander&quot; with LEPS mechanism is introduced. The landing performance is evaluated by 2-dimensional model. The simulation results show that LEPS mechanism has an advantage over normal landing gears.

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Event date： 2014

Language：English  

Recently, personal vehicles have received a lot of attention to expand our mobility for low carbon society and diversification of individual mobility. So far several small vehicles have been developed. However a new thesis of designing and controlling personal vehicles is required, because there are some difference between general vehicle-used environment and personal vehicle-used environment like mixed traffic. In such new kinds of environment, vehicles should have close relationship with drivers. To have closer relationship, personal vehicles must be smaller and lighter. In addition, designing personal vehicle's motion by considering driver's psychological evaluation, we can provide more comfortable vehicle's interface. The author defined these kinds of personal vehicle as Affinitive Personal Vehicle and focused on driver's sense of balance to estimate driver's psychological evaluation. In this paper, author shows that change of vehicle's motion effects on driver's sense of balance, and there is relation between driver's sense of balance and Kaisei evaluation.

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Event date： 2014

Language：English  

The performance of an integrated navigation system is studied through the field experiments on a four-wheeled test-bed rover, AKI, operated in a terrestrial analogue. The AKI rover employs novel mobility and navigation systems which enable challenging long-range operations in natural terrain. AKI has a vision-based localization system aided by sun sensors and an inclinometer for absolute attitude estimation. The integration with absolute direction sensors improves accuracy in absolute positioning, as well as obtaining 5x run-time improvement of visual pose estimation. The paper reports the results of field experiment conducted in Izu-Oshima island in 2013, and discusses current challenges of the system.

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Event date： 2014

Language：Japanese  

JAXA is planning to launch Hayabusa 2 in December 2014. Hayabusa 2 will be equipped with an asteroid exploration rover which is developed by the consortium of universities. A goal of the rover is establishment of the technology for locomotion on asteroid surface. In our previous work, we proposed a new moving mechanism called &quot;Environment-Driven Torquer, EDT.&quot; The EDT is driven by environment temperature with bimetal. In other words, the EDT can move the rover without both battery and CPU. We have developed an engineering model with magnet latch. In this paper, performance evaluation of the EDT is executed by free-fall experiments in ZARM.

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Event date： 2013

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This paper proposes an intuitive teleoperation scheme by using human gesture in conjunction with multimodal human-robot interface. Further, in order to deal with the complication of dynamic daily environment, the authors apply haptic point cloud rendering and the virtual collaboration to the system. all these functions are achieved by a portable hardware that is proposed by authors newly, which is called "the mobile iSpace". First, a surrounding environment of a teleoperated robot is captured and reconstructed as the 3D point cloud using a depth camera. Virtual world is then generated from the 3D point cloud, which a virtual teleoperated robot model is placed in. Operators use their own whole-body gesture to teleoperate the humanoid robot. The Gesture is captured in real time using the depth camera that was placed on operator side. The operator recieves both the visual and the vibrotactile feedback at the same time by using a head mounted display and a vibrotactile glove. All these system components, the human operator, the teleoperated robot and the feedback devices, are connected with the Internet-based virtual collaboration system for a flexible accessibility. This paper showcases the effectiveness of the proposed scheme with experiment that were done to show how the operators can access the remotely placed robot in anytime and place. © 2013 Springer-Verlag.

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Event date： 2013

Language：English  

For high scientific return, planetary rovers need to navigate longer distances autonomously and be less dependent on Earth station. Collaboration between rovers can substantially increase the localization accuracy for all the rovers and therefore, opens up opportunity for future exploration missions. This study aims at introducing a decentralized cooperative SLAM technique for two rovers based on EKF-SLAM and FastSLAM algorithms. Several data fusion methods and motion strategies are formulated. Furthermore, a novel SLAM technique called, cooperative positioning SLAM is proposed. The results show that by fusing information, better localization accuracies can be achieved. To validate algorithms a 3D simulation environment has been developed using opensource tools.

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Event date： 2013

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Event date： 2007

Asteroid Multiband Imaging Camera (AMICA) has acquired more than 1400 multispectral and high-resolution images of its target asteroid Itokawa since late August 2005. In this presentation we summarize the design and the performance of AMICA. In addition we describe the details of the methods, assumptions and model in the calibration, based on both preflight and inflight measurements.

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Event date： 2006.12

Hayabusa spacecraft performed the final descents and touchdowns twice in November 2005. In final descent phase, terrain alignment maneuvers were accomplished to control both altitude and attitude with respect to the surface by using four beams Laser Range Finder onboard. Then Hayabusa spacecraft made dynamic touchdowns the surface of the asteroid by the sampler system to collect samples automatically. This paper presents the terrain alignment maneuver and touchdown scheme. This paper also describes the novel sample horn system and touchdown dynamics. Touchdown tests on the ground are presented. Then the flight results on descent and touchdown dynamics are shown and discussed.

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Event date： 2005.3

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2003年5月に打ち上げられた工学実験探査機「はやぶさ」は2005年夏に小惑星ITOKAWAに到着後、表面のサンプルを採取して2007年に地球に持ち帰る計画である。サンプル採取の前に、高度約10kmの地点から2ヶ月程度、可視光カメラ、近赤外線センサ、X線センサを用いて小惑星の観測を行い、科学観測とともに、着陸地点の選定に役立てることとしている。本稿では、「はやぶさ」の観測センサと観測計画の概要を述べる。

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Event date： 2005

Behavior of Hayabusa spacecraft around the target asteroid is under restraint of illumination/communication geometry. In making operation plans its attitude and maneuver should be satisfied the conditions. The visualization tool of Hayabusa and its field-of-views of cameras have been developed by University of Aizu. It is called as HARMONICS (HAyabusa Remote MONItoring and Commanding System), which prevents operators from confusing real positions and attitude controls. Outline of HARMONICS will be demonstrated in this poster session.

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Event date： 2002

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Event date： 2002

Language：Japanese  

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Event date： 2002

Language：Japanese  

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Event date： 2002

Language：English  

This paper proposes a new mobility system for planetary rover using springs and linear actuators. In the microgravity environment, hopping mobility is a possible choice for enhancing a new mobility of the robot. One method to hop is to press one's own to the ground. The proposed robot cosists of two masses, and can press one's own to the ground using springs. So the rover can hop from the stationary state by transforming the elastic energy to the kinetic energy using the sprigs and linear actuators. Furthermore the robot can land without bounding by transforming the kinetic energy to the elastic energy. The simulation studies and the ground experiments shows that the proposed rover could hop and land.

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Event date： 2002

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Event date： 2002

Language：English  

This paper proposes a four-wheel-type robot with the springs and linear actuators mechanism. In the microgravity environment, hopping mobility is a possible choice for enhancing a new mobility of the robot. The proposed robot can hop and land without bounding in the microgravity environment using the spring mechanism. Furthermore, at the moment of hopping, the wheels are pressed to the ground, so the rover can obtain the horizontal velocity by rotating the wheels. The wheels are also used for the attitude control in the air. The simulation of hopping with horizontal velocity is performed and the equation of kinematics of the rover is developed.

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Event date： 2002

Language：Japanese  

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Event date： 2002

Unmanned lunar geologic exploration of a crater&rsquo;s central peak to investigate subsurface layering is discussed. Rover-lander corporative mission is executed. From a lander which is within 500m from the frank of the central peak, a rover should make a round-trip to the frank and bring samples back to the lander. Multi-band camera, gamma-ray spectrometer, rock-coring mechanism, sampling and transportation mechanism should be on board the rover. Detailed analyses of the returned samples including microscopic spectroscopy and X-ray spectrometry and diffraction should be done in the lander.

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Event date： 2002

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Event date： 2001.11

Language：Japanese  

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Event date： 2001.11

Language：Japanese  

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Event date： 2001.11

Language：Japanese  

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Event date： 2001.11

Language：Japanese  

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Event date： 2001.6

Language：Japanese  

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Event date： 2001.6

Language：Japanese  

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Event date： 2001.1

Language：Japanese  

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Event date： 2001.1

Language：Japanese  

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Event date： 2001.1

Language：Japanese  

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Event date： 2001

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Event date： 2001

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Event date： 2001

Language：English  

This paper presents accurate onboard navigation system for Lunar landers or orbiters, based on the crater identification. The navigation system consists of three stages. At first, craters are extracted from the surface images taken onboard, and the list of positions and radii of detected craters is obtained. The second step is identification between detected craters and known terrain maps obtained by other missions in advance, The final stage is the calculation of position towards Moon-fixed coordinates. To verify the effectiveness and performance of the proposed navigation system, computer simulations including image processing are performed.

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Event date： 2001

Language：English  

This paper presents an autonomous descent and touch-down scheme of the asteroid sample and return spacecraft, MUSES-C. The spacecraft uses some optical sensors. such as a navigation camera (ONC-W1). a laser altimeter (LIDAR), a short range laser sensor (LRF), and an artificial landmark (TM) which is released at about 100m altitude. Navigation system contains image processing, integration of visual and range information, and Kalman filtering. To realize "time of arrival" guidance, the descending plan is uploaded to the spacecraft, considering the asteroid motion. Six degree-of-freedom control is performed by RCS and reaction wheels (RW).
In this paper, after brief explanation of MUSES-C navigation, guidance, and control (NGC) system and descent and touch-down scenario, the navigation scheme mainly focused on image processing, descent guidance scheme, and six degree-of-freedom thruster control are described. To verify the performance of the proposed scheme, computer simulations including Graphical Asteroid Simulator are performed.

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Event date： 2001

Language：English  

The MUSES-C spacecraft, under the development by the Institute of Space and Astronautical Science (ISAS) of Japan for the asteroid sample-return mission, will make dynamic touch-down with the target asteroid when it acquires samples. The touch-down behavior is studied with simulations based on the multi-body dynamics with a friction model. Hardware experiments are carried out to verify the simulation model and evaluate the performance of the contact detector.

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Event date： 2001

Language：English  

This paper proposes a direct geographic recognition scheme from a gray-scale image without shape reconstruction. Several geographic categories are expressed in 3 x 3-arrays of normal-vector directions. Only by looking up a table, observed pixel-values (intensities) in a window are transformed into indices of conformity whether the scene in the window is due to each geographic category or not. Geographical features are extracted by multi-resolution interpretation and fuzzy-logical operations. The feasibility and robustness of the proposed method is shown by some computer simulations.

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Event date： 2001

Language：English  

The authors have developed a small robotic lander named "MINERVA" (MIcro/Nano Experimental Robot Vehicle for Asteroid) and proposed it as an optional payload of ISAS's MUSES-C spacecraft which will conduct the sample return mission from newly discovered new-Earth asteroid 1998SF36. This paper describes the mobility system of the developed robot as well as the surface exploration strategy how to explore and navigate along the asteroid surface. Also the scientific observation functions onboard the robot are detailed.

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Event date： 2001

Language：English  

Global mapping from the sun side and the terminator side are scheduled in MUSES-C mission. The spacecraft keeps the home position around the asteroid during global mapping. This paper proposes a method for a spacecraft to keep the home position autonomously. The spacecraft is navigated based on the image obtained by ONC and the range information obtained by LIDAR. This paper also proposes a global mapping method to estimate the shape of the asteroid based on motion stereo techniques.

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Event date： 2001

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Event date： 2001

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Event date： 2001

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Event date： 2001

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Event date： 2001

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Event date： 2001

Language：English  

In this paper, we discuss tele-driving method for a long driving of a lunar rover. An operator uses virtual world simulator to make command path. The virtual environment of this simulator is constructed with measurement data from a rover on the moon.
We have, however, a communication delay between the earth and the moon. So, there is the difference between old map data which operator used for path planning and new data, which a rover is tracking on. The operator's path command has less reliability to avoid obstacles and to reach the goal. Therefore, to make high reliability of operator's command, we propose Command-Data Compensation (CDC), which compensates this difference as the distortion of the environmental map.

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Event date： 2001

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Event date： 2001

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Event date： 2001

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Event date： 2001

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Event date： 2001

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Event date： 2001

Language：English  

This, paper describes a path planning method for a planetary microrover to make a path oil planetary surface, A planetary rover is required to travel safely over a long distance For many days in unfamiliar terrain, Hence it is very important how a planetary rover processes sensory information to understand the environment and to make decisions, The authors have developed a newly small rover for future lunar or planetary exploration. As a new data structure for a map information. an extended elevation map has been introduced, which includes the effect of the size of the rover. The proposed path planning call be conducted in such a way as if the rover were a point while the size of the rover is automatically taken into account. A map obtained by sensors includes uncertainty. So a path planning scheme based oil traversability probability is also proposed. The validity of the proposed method is verified by computer simulations.

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Event date： 2001

Language：English  

In this paper, we discuss tele-driving system I I or a long driving of a lunar rover and also describe our newly developed small, lightweight lunar rover called Micro-5 and its Visual sensor system. Ali operator uses virtual world simulator to make command path. The virtual environment of this simulator is constructed with measurement data from a rover on the moon.
We have, however, a communication delay between the earth and the moon. So, there is the difference between old map data which operator used for path planning and new data which a rover is tracking on. The operator's path command has less reliability to avoid obstacles and to reach the goal. Therefore. to make high reliability of operator's command. we propose Command-Data Compensation (CDC), which compensates this difference as the distortion of the environmental map.

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Event date： 2000

Language：Japanese  

微小重力環境下においてローバが移動する場合, 従来のように自重により発生する惑星表面との摩擦を利用した方法では移動に限界がある。また小惑星などの微小重力環境下は, 真空で微小重力であるため浮上して移動する方法がすぐれている。本研究ではローバ本体を微小に変位させることで連続して浮上移動を行う方法を提案する。この方法では一回の浮上移動距離が小さいため細かい位置制御が可能となる。

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Event date： 2000

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Event date： 2000

Language：English  

In recent years, many researchers have earnestly studied and developed walking robots. Walking robots have so high mobility that they can move on rough terrain, climb steps, and cross ditches. In the field of planetary exploration, robots with multiple legs are expected to explore inside craters etc. However, so far developed walking robots are too big and heavy to explore the lunar or planetary surface. So this paper proposes a novel design scheme for multi-legged robots. To show the effectiveness of the proposed scheme, the design analysis on static and dynamic motion is performed.

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Event date： 2000

Language：English  

Toward the turn of the century, several schemes sending an unmanned mobile explorer to the moon or Mars are being planned for scientific exploration. Planetary revers are required to explore rough and steep areas such as craters, cliffs, etc. A legged rover can provide higher capability of moving in such a rough terrain than wheeled robots. Therefore the authors have studied a small and lightweight rover which can move across a rough terrain such as a steep slope inside craters. A prototype of the robot with six legs has been developed. This paper presents the system concept, architecture, and configuration of the developed walking rover for planetary exploration. This paper also discusses a walking algorithm.

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Event date： 2000

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Event date： 2000

Language：Japanese  

月表面の広範囲の探査を目的として月面探査ローバミッションが検討されている。探査ローバが目的地に到達するためには, 月面上での自己の位置を知ることが不可欠である。本研究では, ローバが月面上での自己の位置や向きを知るための手法を提案する。本手法では, ローバが活動する昼に必ず観測する事のできる太陽の位置をサンセンサにより測定する事によって, ローバの自己位置を推定する。本手法の有効性をシミュレーションにより検証する。

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Event date： 2000

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Event date： 2000

Language：Japanese  

本研究グループでMicro5を3機製作した。実ミッションにおいて探査ローバは「点」探査から「線」探査へと移りつつあるが, 有益なデータを得るために今後は「面」探査へ移行していくと考えられる。そのためにも, 探査ローバ単体が長距離長期間, 探査活動することは必須となると考えられる。そこで, 本研究ではMicro5ローバを用いてフィールド実験を行ったので, その報告をする。

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Event date： 2000

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Event date： 1999.8

Language：Japanese  

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Event date： 1999

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Event date： 1999

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Event date： 1999

Language：English  

Under the micro gravity environment such as on the surface of small planetary bodies (asteroids or comets), traditional wheeled revers are not expected to move effectively due to the low friction and the inevitable detachment from the surface. This paper discusses the friction-based mobility around the surface of small bodies and proposes a new mobility mechanism that drives the rover by hopping. The hop angle and the velocity are analyzed by numerical simulations, which show the effectiveness of the new mobility system.

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Event date： 1999

Language：English  

Under the micro gravity environment such as on the surface of small planetary bodies (asteroids or comets), traditional wheeled revers are not expected to move effectively due to the low friction and inevitable detachment from the surface. Therefore the authors have proposed a hopping rover suitable for exploration on the surface of small bodies. This paper describes the micro-gravity experiments of a proposed hopping rover which is driven by an internal DC motor torquer. The proposed rover could hop under a micro gravity environment. Experimental results are compared with the computational simulations.

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Event date： 1999

Language：English  

This paper describes a newly developed rover with small size, light-weight, low power consumption. In recent years, many researchers have extensively studied and developed unmanned mobile robots for surface exploration of the moon or planets. A lunar or planetary rover is required to travel safely over a long distance for many days in unfamiliar terrain. This paper presents scientific signification, requirements, and technology of a lunar or planetary rover. This paper proposes a new mobility system, which has four wheels and one supported wheel. This novel suspension system is a simple and light mechanism like a four-wheeled rover and provides a high degree of mobility like a six-wheeled rover. The performance of the developed rover is shown by some experiments.

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Event date： 1999

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Event date： 1999

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Event date： 1998.10

Language：Japanese  

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Event date： 1998.3

Language：Japanese  

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Event date： 1998.3

Language：Japanese  

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Event date： 1998

Language：English  

For evaluating the basic navigation techniques for a planetary rover an a natural terrain, long range navigation experiments had been performed at Mt.Mihara volcano of Izu-Ohshima Island in September of 1996. The experimental rover succeeded in traveling over 800[m] autonomously without hitting any obstacle. This paper describes navigation functions installed in the test-bed rover. This paper also presents the results obtained during the first long range navigation test.

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Event date： 1998

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Event date： 1997

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Event date： 1997

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Event date： 1997

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Event date： 1996.3

Language：Japanese  

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Event date： 1996

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Event date： 1996

Language：English  

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