Tadashi Komatsu

Dynamic walking and running of a bipedal robot using hybrid central pattern generator method

This paper presents simulation and experimental results of dynamic walking and running of a bipedal robot. We proposed the hybrid central pattern generator (H-CPG) method to realize adaptive dynamic motions including stepping and jumping. This method basically consisted of CPG models, but was added the force control system that controlled the acting force from a leg to a floor in the vertical and the horizontal directions separately. At this moment, 2D walking and running was realized on level ground and a slope with a speed of 1.6 m/s.

Control of a space flexible master-slave manipulator based on parallel compliance models

This paper proposed a bilateral controller of a flexible master-slave manipulator (FMSM). A FMSM consists of a conventional compact rigid master arm and a flexible slave arm, and will be used in outer space in the future. This controller realizes stable compliance control and vibration control. The key idea is that this controller has dual compliance models.

Precise velocity control of a bipedal robot using CPG circuits in creating different behaviors

Abstract In this paper, we have extended our previous work, which created several motion phases in running and walking movements with a central pattern generator (CPG) model, to controlling the robot’s walking speed easily and precisely within a wide speed range to investigate the possibility of CPG in the domain of bipedal robotic locomotion. Our method proposed herein basically used our hybrid CPG (H-CPG) model. This model consisted of a rhythm generator using CPG, a force controller, and an attitude controller. We have also introduced a modulation mechanism using a velocity feedback loop in this force controller for the precise control of acting forces from the tip of the support leg to the floor and the walking stride length. This mechanism can realize accurate modulation of the walking velocity reflecting an error between the target velocity and the current velocity in real time. Numerical simulation results show the effectiveness of the proposed method for realizing precise control of the locomotion speed in both backward and forward stable walking.

Control of a flexible master-slave manipulator using dual compliance models

This paper presents a newly developed bilateral controller of a flexible master-slave manipulator (FMSM) system. A FMSM consists of a conventional compact rigid master arm and a flexible slave arm, and will be used in outer space and in the construction field in the future. There are two problems in controlling a FMSM. One is the vibration of a flexible link. The other is the deformation of a flexible link when a slave link contacts with an object. The proposed controller is effective in restraining the vibration of a flexible link and in protection from adding too much force to a flexible link. For this purpose, the key idea of the proposed method is that this controller has dual compliance models, and the design is done for each model considering the elasticity of a master and a slave arm. Each arm moves along the desired path which was calculated in this model. Also, a slave controller has a vibration controller. As the initial study, a 1 d.o.f. system was considered. The effectiveness of the proposed ...

Precise Velocity Control of a Bipedal Robot using CPG Circuits in Creating Different Behavior

This paper investigates the possibility of a Central Pattern Generator (CPG) method in the domain of bipedal robotic locomotion. We extend our previous work on creating several motion phases in running and walking movements to changing the robot’s walking speed easily and precisely within a wide speed range. The proposed method used our hybrid CPG (H-CPG) model basically. This model consisted of a rhythm generator with CPG, a force controller for a leg and an attitude controller. Then this model was added a modulation mechanism for acting forces from a tip of a support leg to the floor and the walking stride length, using a velocity feedback loop. Numerical simulation results show the effectiveness of the proposed method for realizing precise control of the locomotion speed in both backward and forward walking.

Experimental Study on Autonomous Retrieval/Release of a Moving Payload by a Free-Flying Space Robot*

Abstract We proposed the strategy and control system of an autonomous satellite retrieval/release mission of a free-flying space robot with an attitude-controlled base. This mission consists of tasks of retrieving a moving payload, equipping parts with the payload, and releasing it on an orbit again. Our control system consists of position/attitude control of both a spacecraft and manipulators, reaction torque compensation for a spacecraft, and impedance control of a space manipulator. The effectiveness of this system was shown by the simulation experiment of performing this mission with a two dimensional operation testbed of a space robot equipped with thrusters and a control moment gyro. The complete mission was implemented successfully.