Kouichi Watanabe

Mechanical Compliance Control System for a pneumatic robot arm

The design and control of robots from the perspective of human safety is desired. We propose a mechanical compliance control system as a new pneumatic arm control system. However, safety against collisions with obstacles in an unpredictable environment is difficult to insure in previous system. The main feature of the proposed system is that the two desired pressure values are calculated by using two other desired values, the end compliance of the arm and the end position and posture of the arm.

TORSO: completion of egocentric telegnosis system

We have proposed a system that can acquire natural and comfortable visual information and can accurately track the head motion of the person. The conventional imaging device for head-mounted display was only able to express the 3-axis rotation of the neck but our device has expressed the head motion as well as the translation motion of the neck.

An Avoidance Method of Singular Configurations in a Master-Slave System Using Intervening Impedance

It is necessary to naturally avoid singular configurations of each slave robot in order to achieve an ideal telexistence master-slave system. We propose a method for the avoidance of singular configurations by using intervening impedance. In this method, the parameters of the intervening impedance are adjusted by the manipulability ellipsoid. This method is applied to a master-slave robot. As a result, singular configurations are avoided by the proposed method.

Design Method of High Performance and Low Power Functional Units Considering Delay Variations

As VLSI technology advances, delay variations will become more serious. Delay-insensitive asynchronous dual-rail circuits tolerate any delay variation, but their energy consumption is more than double that of the single-rail circuits because signal transitions occur every cycle in all bits regardless of the input bit pattern. However, in functional units, a significant number of input bits may not change from the previous input in many cases. In such a situation, calculation of these bits is not required. Thus, we propose a method, called unflip-bits control, makes use of the above situation, to reduce energy consumption. We evaluate the energy consumption and performance penalty for the method using HSPICE and the verilog-XL simulator, and compare the method with the conventional dual-rail circuit and a synchronous circuit. Our evaluation results reveal that the proposed asynchronous dual-rail circuit has a 12--60% lower energy consumption compared with a conventional asynchronous dual-rail circuit.