Advanced Robotics

Matsuno, Fumitoshi

doi: 10.1163/156855301750398310pmid: N/A

Damoto, Riichiro; Kawakami, Atsushi; Hirose, Shigeo

doi: 10.1163/156855301750398329pmid: N/A

In our COE/TITech project, we have been studying a heterogeneous robotic system of decentralized autonomous agents with a leader agent, known as the 'Super-Mechano Colony' (SMC), which has characteristics of both the hierarchical and distributed control systems. This paper explains the basic concept and a physical test-bed of a SMC and discusses one example, specifically planetary rovers, for SMC. In order to provide a test-bed for the basic architecture, a homogeneous colony of 12 child-machines and one mother-ship were designed and built. Each child-machine of the colony has an octagonal body mounted on two independent axle wheels and each robot is equipped with a manipulator arm. Each robot has 5 actuated d.o.f.; specifically, two motors rotating the independent wheels of the body, one motor for opening and closing the gripper, one motor for lifting and lowering the arm, and one motor for rotating the body. While the child-machines are grasping the stud attached around the mother-ship, each child-machine can charge its own battery from the charger mounted on the mother-ship.

Shugen, ; Watanabe, Mitsuru

doi: 10.1163/156855301750398338pmid: N/A

Hyper-redundant manipulators have very large degrees of redundancy, thus possessing unconventional features such as the ability to enter a narrow space while avoiding obstacles. In this study, a time-optimal control scheme is proposed for a hyper-redundant manipulator that was realized by coupled tendon-driven mechanisms. In the mechanisms, a pair of tendons for driving a joint is pulled from base actuators via pulleys mounted on the base-side joints and the degrees of actuation redundancy exist. The time-optimal trajectory planning problem is solved by using the phase-plane analysis and the linear programming technique. Computer simulations were also performed to show that the proposed scheme makes full use of the actuation redundancy of tendons and their coupled function to shorten motion time.

Caccavale, Fabrizio; Siciliano, Bruno

doi: 10.1163/156855301750398347pmid: N/A

This paper is aimed at presenting solution algorithms to the inverse kinematics of a space manipulator mounted on a free-floating spacecraft. The reaction effects of the manipulator's motion on the spacecraft are taken into account by means of the so-called generalized Jacobian. Redundancy of the system with respect to the number of task variables for spacecraft attitude and manipulator end-effector pose is considered. Also, the problem of both spacecraft attitude and end-effector orientation representation is tackled by means of a non-minimal singularity-free representation: the unit quaternion. Depending on the nature of the task for the spacecraft/manipulator system, a number of closed-loop inverse kinematics algorithms are proposed. Case studies are developed for a system of a spacecraft with a six-joint manipulator attached.

Ono, Kyosuke; Yamamoto, Koji; Imadu, Atushi

doi: 10.1163/156855301750398356pmid: N/A

We investigated a control method to realize the three different types of free giant swing motions produced by a two-link horizontal bar gymnastic robot. By evaluating the eigenvalues of the transitional error matrix on the Poincare plane, it was found that the stable giant swing motions could be obtained by a proposed configuration control, in which the actuated joint torque is controlled such that the measured state variables follow the reference configuration with respect to the angular position of the passive joint. We also demonstrated that the two types of stable giant swing motions could be accomplished by the configuration method.

Miyazaki, Masahiro; Sampei, Mitsuji; Koga, Masanobu

doi: 10.1163/156855301750398365pmid: N/A

In this paper, we consider the motion of a gymnast approaching a horizontal bar and focus on the acrobot. In the stance phase, we set the jump with a desired speed direction and a desirable angular momentum as the control objective, and achieve it by introducing an output feedback control with a suitably chosen output function. In the flight phase, a suitable desired trajectory enables us to control the posture when the acrobot approaches it. Finally, numerical simulations are shown to demonstrate this motion.

Fukushima, Edwardo F.; Kitamura, Noriyuki; Hirose, Shigeo

doi: 10.1163/156855301750398374pmid: N/A

This paper describes the implementation details, advantages and potential applications of autonomous tethered mobile robot systems using the 'hyper-tether' concept. Hyper-tether is a new research area on tethered connections, which provide tethering among different mobile robot types, such as a robot with the environment and a robot with humans and animals. Its basic function is to actively control the tether's tension and/or length, but it also considers tether launching, anchoring, power delivery, data communication cabling and built-in trajectory command generation capabilities. Many of these features can be efficiently applied to build a tethered mobile robot system which remotely manipulates a working tool that can be useful for land-mine detection and removal, trimming of gardens and grass cutting of wide areas (e.g. golf courses, soccer and baseball fields), spraying of agricultural chemicals, forestry and construction works, etc. In this paper, a simple prototype of hypertether's winch-tether pair and a working tool equipped with a grass cutter was constructed, and basic experiments were performed to demonstrate the validity of the proposed system.