森 治

This paper shows the dynamic properties interpreted about a falling cat motion. A new interpretation on non-holonomic turns was presented from coning effect point of view. It infers even the kinematics effect independent of dynamics may still drive the non-holonomic turn. However, that motion is, in this paper, proved not fully true and shown partly dependent on the inertia properties. This paper presents new interpretation findings which show the resulted non-holonomic turn may become reverse dependent on the moment of inertia ratio. This paper corrects the motion structure interpretation, in which a very interesting combination of kinematics and dynamics is found to govern the motion. And a numerical example is given for the spacecraft attitude maneuver, whose time history is explicitly described. A special feedforward control law is derived and applied to the maneuver. The results show the control strategy established well functions and enables the reorientation to be accomplished only via internal torque. What is presented does provide a comprehensive strategy widely applicable to spacecraft and space robots.

Discussed in this paper are the results of the mission analysis of near Earth asteroid flyby missions using miniature Asteroid Interceptors. The Interceptor is an autonomous self-contained interplanetary probe with 10kg mass which is now under development in ISAS/JAXA. It has the capability of navigating itself autonomously to flyby the target asteroid using optical navigation system. The image of the asteroid taken by the camera onboard at the closest approach is the main science output of the mission. Firstly discussed is the mission by a single Interceptor, which enables the minimum size interplanetary mission. The interceptor is launched as a piggy back mission on a geostationary mission, separated on a geostationary transfer orbit (GTO), kicked by a solid rocket motor, and injected into an orbit suitable for encountering the asteroid. It is shown that the utilization of the Earth synchronous orbit and the Earth swing-by drastically increase the number of the possible target asteroids, which enables the selection of more scientifically interesting target for a given opportunity. The second mission concept discussed is the multiple asteroids exploration with a single launch. A straightforward application of the single Interceptor mission, that is, the mission by several independent Interceptors is shown firstly, and an option to overcome the difficulty in performing critical operation of multiple spacecrafts simultaneously is also discussed. The list of the target asteroid candidates, detailed mission sequence and maneuver parameters are shown for the assumed example mission.

This paper shows the dynamic properties interpreted about a falling cat motion. In the IAC in Vancouver last year, a new interpretation on non-holonomic turns was presented from coning effect point of view. While the last year's synthesis infers even the kinematics effect independent of dynamics may still drive the non-holonomic turn. However, that motion is, in this paper, proved not fully true and shown partly dependent on the inertia properties. This paper presents new interpretation findings which show the resulted non-holonomic turn may become reverse dependent on the moment of inertia ratio. This Fukuoka conference paper corrects the motion structure interpretation, in which a very interesting combination of kinematics and dynamics is found to govern the motion. And a numerical example is given for the spacecraft attitude maneuver, whose time history is explicitly described. A special feedforward control law is derived and applied to the maneuver. The results show the control strategy established well functions and enables the reorientation to be accomplished only via internal torque. What is presented does provide a comprehensive strategy widely applicable to spacecraft and space robots.

Institute of Space and Astronautical Science (ISAS) of Japan Aerospace Exploration Agency (JAXA) is currently planning the missions that the small probe 'interceptor' flybys near-Earth objects. Interceptor is very small probe. An interceptor observes spectrum, takes close images, and determines mass of a NEO (near earth object) during a flyby. The weight of interceptor is less than 10 kg. This paper shows three types of missions. In general, it is impossible to determine the relative orbit during flyby only with optical information. Thus the optical navigation needs to be combined with the radio navigation that should provide the relative velocity vector information. In this paper, the integrated guidance and navigation strategy of interceptor is proposed. The interceptor needs the thruster for the attitude and orbit control. This paper introduces the development of the gas-thrust equilibrium thruster for small satellites.

Institute of Space and Astronautical Science (ISAS) of Japan Aerospace Exploration Agency (JAXA) is currently planning the missions that the small probe 'intercepter' flybys near-Earth objects. In general, it is impossible to determine the relative orbit during fly-by only with optical information. And usually the optical navigation needs combined with the radio navigation that should provide the relative velocity vector information. This paper first discusses the new integrated guidance and navigation strategy, provided the relative velocity vector between the probe and the object is obtained. And next, paper presents how to obtain full orbit property using the camera and velocity collection information for the guidance. Finally, this paper shows the outline of experiment to verify this strategy.

Solar sails are the spacecraft that are propelled by sunlight. The Institute of Space and Astronautical Science (ISAS) of Japan Aerospace Exploration Agency (JAXA) has studied the solar sails which are spinning and deployed by centrifugal force. One of the technological difficulties to be realized is how to design the spanned spinning solar sails to maintain the stability while those huge membranes unfurl with deformation and oscillation. In this paper, an attention is focused on the out-of-plane oscillation and an analysis is presented about the dynamics so that the characteristic parameters are identified as for the stability of those spinning solar sails.

Japan Aerospace Exploration Agency (JAXA) is currently studying on the "Solar Sail" propulsion for future deep space explorations. One of the key technologies to realize the solar sail is how light and how compact we can make the photon acceptance surface. JAXA has conducted extensive studies on utilizing centrifugal force to deploy the photon acceptance surface. The final objective is to realize the 7.5μmthickness and 50m diameter polyimide membrane, combined with thin flexible solar cells, as the photon acceptance surface that will be needed around the Jupiter orbit. In the August 9, 2004, JAXA has launched the S-310 sounding rocket, which tested two different shapes of membranes during the zerogravity flight. The first type of the membrane looks like a "clover-leaf", and another is like a "fan". These two membranes, both of them have 10m diameter, were unfolded sequentially during the zerogravity flight under the free spin condition, and their behavior was observed by onboard cameras. This paper focuses on the "clover-leaf" solar sail, which was fully deployed successfully, and introduces the S-310-34 experiments, and then shows the flight results and postflight evaluations.

「はやぶさ」の成果と技術を継承する次期小天体探査を検討するワーキンググループが、今年3月に発足した。全国約150名のメンバーを「ミッションデザイン」「航法誘導制御」「オービターサイエンス」「サンプリング」「表面探査パッケージ」の課題別にサブグループに分け、2006年度中のミッション提案を目指している。現在は、例えばＣ型小惑星で層序情報を保持した試料を採取する技術や、産状を観察できるローバなどを戦略的に検討している。本講演ではミッションの意義、探査対象に関する議論を整理し、開発の進捗を報告する。

ISAS/JAXA is studying a deployment method using centrifugal force for solar sail mission. In this paper, the clover type sail is investigated. The deployment sequence consists of two stages. In order to analyze the motion of the dynamic deployment, S-310 flight experiment is conducted. In this experiment, the clover type sail of 10 m diameter is deployed dynamically. Numerical simulations by multi-particle model are also conducted to analyze the complicated motion. The experiment and simulation results are compared with each other to validate the analytical model. On the other hand, we schedule to conduct a balloon experiment. The clover type sail of 20 m diameter is deployed statically. The mechanisms for first stage and second stage deployments are introduced.

This paper discusses a ground experimental demonstration on formation deployment for spinning tethered formation flying. The spinning tethered formation flying is the system that rotates around the center of mass of it under the condition that each spacecraft is connected by tethers. Therefore the system can achieve formation deployment using tether tension as well as thrusters. Most of the past studies about the system focused on theoretical studies. However it is important to evaluate it experimentally. In this paper, we introduce an experimental set-up using two-dimensional micro-gravity simulators to evaluate the formation deployment, and discuss results of the experimental demonstration.

A solar sail is one of propulsion systems for near future interplanetary mission, which utilizes solar pressure for thrust by reflecting sunlight with very large membrane. A solar sail is proposed for an engineering experiment satellite. Although a deployment experiment is necessary in order to verify the solar sail design, it is difficult to perform an experiment of large membrane on the ground because of its lower stiffness. To solve this problem, we used a sounding rocket. On the last August we launched our sounding rocket S-310 No.34 to investigate two solar sail designs « clover type sail (previously it was called reverse umbrella type sail)» and «fan type sail». The rocket was successfully launched and we got some pictures during deployment of the sails. In this paper we will report the result of the experiment.

As one means of propulsion for the future deep space explorers, Japan Aerospace Exploration Agency (JAXA) is conducting research on the "Solar Sail", which is driven by the momentum of photons from the sunlight. Among several candidates of deployment and shape-forming strategies of the sail, JAXA has been focusing on the utilization of centrifugal force. However, it is very difficult to conduct the deployment experiment of the large membrane structure due to aerodynamic drag and gravity. Then, In August in 2004, we performed the experiment to deploy two types of membrane structures made by polyimide film with a sounding rocket. During the ballistic flight, two types of membranes are deployed in turn. We call the two sails "Clover-type sail" and "Fan-type sail", respectively. The cameras on the rocket recorded the images of the membrane and various sensors measured the behavior of the membrane. The data are transmitted to the ground as the telemetry. We succeeded in deploying the membrane whose diameter is 10 meters in space for the first time in the world. This paper deals with the experiment with the rocket and the result of the Clover-type sail.

In the paper, a new type membrane deployment method is proposed, and locally full-deployment state can be achieved in the deployment from folded state. The authors conduct fundamental ground experiments of the proposed membrane deployment using an experimental set-up system including two-dimensional micro-gravity simulators, and tether and membrane control mechanisms developed at Tokyo Institute of Technology. The simulator system is composed of a 3m*5m flat-floor glass and floating satellite simulators with gas-thruster. The authors use 3 satellite simulators, triangular membranes, the tether control system and newly developed drum mechanisms for membrane control. The drum mechanism can control membrane extension speed. A virtual structure control method is applied to control the three satellites for formation flight, and PID type control is adopted to control the the membrane control. From the experiment the authors obtain 2-dimentional deployment behavior and discuss the feasibility of the proposed method comparing with corresponding numerical simulation results.

This paper proposes a novel self-reconfigurable parallel robot which is capable of self-reconfiguring to other various types of planar parallel robots on a horizontal plane. The limbs (legs) of the proposed parallel robot are 2R (two-revolute-joint) open kinematic chains whose second joints are unactuated. Reconfiguration is done by the coupling and decoupling of the platform(s) and limbs, which enables the proposed parallel robot to change workspaces and exchange tools. Uncertainty singularities enable such a robot to self-reconfigure without additional actuators at its coupling mechanism. This paper proposes appropriate uncertainty singular configurations for coupling and decoupling. In addition, it is shown that there exist geometrically stable uncertainty singular configurations, which are useful especially for decoupling. Experiments are carried out to verify the self-reconfiguration.

We have proposed a self-reconfigurable parallel robot, which can be configured to 4R and 5R closed kinematic chains. This paper proposes a parallel mechanism mobile robot by mounting it on a crawler mechanism. The combined mobile robot can gain some useful functionalities from the advantage of its parallel mechanism other than just locomotion, such as getting over a bump by control of its center of gravity and carrying an object by making use of its shape. Furthermore, the robot can form three-dimensional structures with other such robots and reach a certain height in which the single one cannot. We have developed two such robots that are self-contained. This paper analyzes the motions of the functionalities and verifies them experimentally using the robots.

In this paper, we propose one membrane deployment method: tether-controlled spinning deployment. Very large, thin and flexible membrane (sail) is packed and then is deployed in orbit. In the process of membrane deployment, we use controlled tethers to stably deploy the membrane. Some types of the system are proposed, and the characteristics and technical issues are briefly mentioned. Numerical simulation results using a distributed mass-tether network model show the potential advantage of the proposed method. An experimental set-up of the proposed deployment using the two-dimensional micro-gravity simulators developed at Tokyo Institute of Technology is introduced, and the result of preliminary deployment experiments with a thin membrane of 1m-sized is shown.

We have developed a self-reconfigurable robot which can form a 5R closed kinematic chain, only two of whose joints are actuated. This paper discusses its dynamic rolling. When it rolls, it has one DOF of its absolute orientation besides two DOFs of its shape. We show that the absolute orientation is subject to an acceleration constraint, not a velocity constraint. Therefore, the dynamics of the rolling motion needs to be formulated to control it. This paper proposes a controller which can reduce its negative acceleration caused by gravity. The shape and orientation of the robot cannot be controlled simultaneously. This paper proposes a control strategy switching shape and orientation controllers. We verify the effectiveness of the control strategy by simulations and experiments.

This paper proposes whole quadruped manipulation, a novel manipulation with a quadruped robot using its whole body. The quadruped robot we have developed can stand on its knees and its two legs can serve as arms. The robot can hold a relatively big and heavy object in its two arms, and can manipulate it by moving its body. The desired configurations of the robot during the manipulation are at an increased mobility singularity if the whole distal links of its two legs are in contact with the floor or ground. The problem with the singularity is that the mobility of the robot changes significantly around it. This paper shows a contact type for the two legs to avoid such a singularity. We verify that our quadruped robot can perform the proposed manipulation experimentally.

This paper proposes a reconfigurable planar parallel robot by coupling two 2R open kinematic chains (or 2-link robots), the first joints of which are passive. We show that they can reconfigure to a 5R closed kinematic chain which has the same number of actuators as its degrees of freedom. They can also reconfigure to a 4R closed kinematic chain plus one actuated link. The parallel robot has only two actuators but can have multiple functions by reconfigurations. Due to the passive joints, whether or not the 2R open kinematic chains can couple with each other is a non-trivial problem. We propose coupling sequences for forming the 4R and 5R closed kinematic chains and verify those experimentally.

We propose the concept of Tethered Satellite Cluster Systems. The system consists of the satellites connected by tethers,and keeps and changes the formation with active tension/length control of the tether. The purpose of the system is the saving of the thruster fuel required for the coordinated mission and the improvement of the control precision,using tether tension. The system is applied to tethered service satellites,which perform the missions,for example an autonomic inspection,casting,capture,moorage and deorbit of an uncontrolled satellite. In this paper,we treat the rotating motion; satellites rotate on the center of the mass of the system with the formation in same plane. We establish the coordinated control method using tension and thrust. This control method can decrease the fuel consumption of the thruster,for utilizing the tether tension/torque equilibriums. It can also improve the control precision. Moreover,we establish the formation control method without thrust for the transition to the objective circular motion and the system reformation. © 2001 by the American Institute of Aeronautics and Astronautics,Inc. All rights reserved.

In this paper, we propose the concept of Tethered Satellite Cluster Systems, as an application of the RoboSat Clusters. The system consists of some satellites joined by tethers, and keeps and changes the constellation with tension/length control of the tethers to perform various orbit service missions. We formulate the motion of the system in order to analyze the dynamics and establish the methods of coordinated control of tension and attitude of the satellite. In addition, we develop a ground experiment system including a reel mechanism for the tethered satellite cluster systems. We outline the system components and show results of the fundamental experiments for verification of the reel mechanism and the control methods.

We had the opportunity to launch prototype CanSats, small satellites the size of a soft drink can, on an amateur rocket in September 1999 (ARLISS: A Rocket Launched International Student Satellites). We developed four CanSats for ARLISS: CanSat Type1 and Type2 missions are experiments of two different types of mechanisms for tether applications, CanSat Type3, is a communications and electronic devices test satellite, and CanSat Type4 is equipped with CCD camera and transmits video image. The development period of time is less than 5 months. In this paper, we describe 4 CanSats missions, subsystem designs including the ground station and the results of ARLISS experiment.

Copyright © 1997 The American Institute of Aeronautics and Astronautics Inc. All rights reserved. The dynamics of tethered systems with friction between the tethers and the bodies, as well as impact between the bodies, is investigated in this paper. A two-dimensional formulation of the dynamics between a captured spinning target and a tether with load masses at the end of the tether is presented. The tether mass is neglected but the slack in the tether is considered. Furthermore, the impacts between the tether load masses through the tether, as well as between the load mass and the target, are treated using the Lagrange impulse method. During the winding process, the dynamic and static friction between the target and the tether are considered. Numerical simulation results shed light on the complicated motion of the tether endmass and the target. The effect of tether tension control for damping the target spin is briefly discussed.

We have developed a quadruped which can perform manipulative tasks by standing on its knees. A knee-roller contact mode was proposed to maintain kinematic consistency. This paper shows that its singularity does not appear in the configurations for the tasks. The robot can effectively change an applied force by shifting its center of gravity.