When a manipulator is handled with human force, it is necessary to reduce reaction force caused by inertia, friction, gravity, etc. This paper describes an active power assistance system for a direct-drive manipulator, which assists handling force with motor, and force detection system for that purpose. This method detect handling force by combination of motor-torque detection with motor-current and rotation detection with internal sensors (tacho-generator etc.) . It does not need special force sensors. Some configurations of power assistance system are also shown. Effectiveness of the proposed method is demonstrated by feasibility experiments.

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In the artificial environment like inside of a building, the scene from the robot's view point usually consists of line segments. This paper proposes a new effective algorithm to extract line segments from a picture for a robot vision. It should be paid attention to the fact that directions of gradient of brightness on a line segment are almost equal in a picture. In this algorithm, pixels having the following properties are firstly connected together to generate a small area: (1) Magnitude of the gradient of brightness is greater than a threshold value. (2) Direction of the gradient of the pixel falls within a given small range of directions. (3) All pixels are connected each other. Such a small area is generated like a stick on the border line of an object in the original picture. Line segments can be extracted by applying least square method to each generated sticklike areas. The advantages of this method are; (1) the algorithm needs only one scan to generate all sticklike small areas and is suitable to process an original picture in short time, (2) the effect of local noise is greatly reduced with statistical calculations to fit line segments on the small areas, (3) sticklikeness of each small area can be evaluated by ellipticity of its equivalent ellipse. This paper also shows experimental results to prove that line segments can be effectively extracted from an original picture by uniform algorithm on the proposed method.

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This paper describes a walking control algorithm taken ground distortion into consideration. In this case, the problem is focussed on the point how the body attitude and altitude can be maintained over soft ground. Although the body inclination can be recovered using an attitude sensor in a conventional walking machine, it is generally difficult to realize the walking motion keeping its constant body height without using a suitable altitude sensor.
Let us consider a human walking in the terrain with unknown gtround softness. It is seemed that in such a condition, human moves his center of gravity after he confirms to support his weight in new support leg using distributed force sensors output behind foot.
On basis of these considerations, the authors propose a control algorithm that body attitude and altitude can be maintained simultaneously using foot force sensor. The proposed control algorithm can be classified into two parts. One is applied during support leg changing phase, and the other one is applied during body propelling phase. The effectiveness of these control algorithms is checked through walking motion experiments using a hexapod machine with alternating tripod gait.

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In order to increase the terrain adaptability, the walking robot has to install visual sensor. The paper defines the visual sensor for walking robot as a MAp Realization System, abbreviated as MARS, and investigates the way to realize practical 3 D range finding device which forms the major part of the MARS.
Firstly the improvement of the range finder's performance to separate and extract projected laser slit light in ambient light is investigated. A video signal processing procedure named DDD (Dual signal extraction with Delay and Difference) method, which extracts the pulse signal by making use of the dual pattern of positive and negative pulse in differenced video signal, is proposed. The specific method of DDD, that extracts only the maximum pulse, is shown more effective and is called MaxDDD.
A range finder with the signal processing system having optical interference filter, MaxDDD video signal processor and noise reduction software applies for the signals of adjacent scanning lines is constructed and shown its high S/N ratio.
Secondly the structual and algorithmic consideration to realize real time compensation of the swinging motion of the walking robot and to generate the terrain map while walking is made. As a result it is shown that the position measurement of one point is executed within 240 micro second and thus enabled to generate a map in real time. The constructed MARS range finder device weighs 1. 8 kg and is designed compact.
By these considerations the paper shows the feasibility to realize a practical visual system for walking robot.

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A method of cooling which improves the response of the actuator using a Ti-Ni shape memory alloy is proposed. It is shown that the cooling rate of the shape memory alloy increases remarkably by the use of the aluminum heat sink. The characteristics of the new actuator are described.

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