This paper presents an LSI-oriented high-performance processor for the inverse kinematics to control the position and orientation of the end-effector of a robot. It is well known that a geometric approach is useful in finding such joint angles. To achieve the high-speed transformation, a new hardware algorithm based on the coordinate rotation is proposed which can be implemented by the CORDIC technique. By means of the algorithm, an inverse-kinematic processor is designed which has attractive features of high-speed, compactness, and flexibility for any kinds of manipulators. The processor has been implemented on the breadboard using TTL-IC's in order to confirm the operation. Assuming the 2μm CMOS technology, the chip evaluation of the processor is discussed from the viewpoint of the speed and chip area. Although the hardware size is almost same as that of an 8-bit one-chip microcomputer, ultra-high-speed transformation can be achieved. As a result, it is established that the inverse kinematic processor is very effective for the practical applications.

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The basic problem to generate terrain map using the range finder's 3D information for mobile robot is considered. The representation of terrain map is investigated in the first place and a method called torus memory representation is introduced. The method to generate terrain map is divided into visible and invisible regions and discussed separately. As to the visible region, a method based on the sequential calculation of mean and mean deviation is proposed. As to the invisible region an associative processing of the memorized information (abbreviated A-interpolation method) which has been proposed by the authors for interpolation of invisible terrain is improved to bestow higher versatility and real time computation capability. Two experiments are made. One experiment is to measure and reproduce visible area map of the model terrain by using the MARS range finder mounted on the quadruped walking vehicle TITAN III. The other is the computer simulation experiment to compare the conventional method with proposed modified A-interpolation. The validity of the proposed methods are verified by these experiments.

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This paper presents an active type of positioning methods for vehicle robot moving on three dimensional space such as the agricultural and constructional vehicles in terrain and the inspective vehicle in chemical and nuclear power plant, etc..
If the directions to three or more reference points on environment can be simultaneously measured on a vehicle, the vehicular position and attitude can be calculated from the triangulation principle.
This paper realized this concept by use of laser beam with high directivity and corner cube (retro reflector) with unique reflectional characteristics. Corner cubes are set on the reference points respectively. The directions of laser beams emitted on the vehicle are controlled so as to hit usually the corner cubes. This control, namely the laser tracking control, is easily performed on vehicle by detecting the laser beams reflected from corner cubes. During the laser tracking the directions to the corner cubes are measured on vehicle by the laser beams. And the vehicular position and attitude are determined from above measuring data by the iterative algorithm based on the triangulation principle.
This paper also discusses the effectiveness of our method through some experiments for the limited case that a vehicle moves on two dimensional space.
For the accurate position finding of a vehicle, the vehicle needs to differentiate the reference points and other objects on environment. The use of simple corner cube in our method can easily solve this problem with a slight equipment investment to environment. Further the use of of laser beam with high directivity enables the vehicle to determine the accurate position by the simple algorithm.

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This paper describes an algorithm of collision detection between moving robots in off-line teaching. Graphical simulation of robot motion has been recognized to be useful for industrial applications, since visual check-up of the programmed 3-dimensional motion can confirm the programmer's intention easily. But it is still difficult to visually detect a collision between moving robots. Therefore, in this paper, the requirements necessary for detecting collisions between robots are described first and an algorithm meeting them is proposed. In this method, we assume that the motion of each moving object is described as a function of time. A collision occurs in one of the two cases; a vertex collides with a plane or an edge collides with another edge. By solving the equations that satisfy the conditions of collision, we can get the time and position of the collision between moving objects. The equations are shown and the complexity and error of the computation is discussed. Finally, some issues in implementation are addressed and experimental results are shown to prove the effectiveness of the algorithm proposed in this paper.

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Industrial robots have lumped flexibility at joints as well as distributed flexibility due to elasticity of arms. Because of the flexibility, undesirable vibration occurs during motion. In this paper, an equivalent spring which represents the flexibility is introduced, and equations of motion of robot links and equations of vibration of end-effector are derived by using Lagrangian dynamics. Motor torques should be controlled in such a way that required response of motor positions is achieved and at the same time the vibrations disappear as quickly as possible. For measuring the vibrations, three accelerometers are installed at the tip of the forearm. A robust feedback control law is derived by using the root locus technique. Several successful experimental results are shown.

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This paper deals with an ultrasonic orientation sensing system. The system measure the orientation of an objective surface, using the phase information of the reflected echos.
In order to identify the three-dimensional orientation, the system needs two phase difference of three receivers at least. However, the phase difference can not be distinguished over one period of the reflected echo. Then the measurable range is restricted in a relatively small orientation.
This paper propose a method to overcome the difficulty by increasing the number of the receivers. The closely arranged receivers encircling a transmitter can provide the smaller difference between two adjacent echo trajectories. They hold the individual phase difference in a sufficientry small value and allow the orientation measurement over a wide range.
The paper shows the principle of measuring two directional angles of a surface normal based on the least squares method. The redundant phase information obtained by the many receivers also contribute to the improvement of the accuracy.
Two prototype sensing system using the 6 or 8 receivers are constructed and the experiments demonstrate the basic performance of the system. It is shown that the high resolution measurement is possible over a wide range of orientation.

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When a robot moves to a goal, the role of vision is to guide the robot toward the goal; neither its precise position at each roving point nor understanding of detailed scene structure are needed.
This paper describes a simple method for the real-time visual guidance to a sub-goal specified on the markless floor by tracking two markers in the scene. Ideas for saving computing time, essential need for the real-time feedback, are described.

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Mechanical problems of the terrain-adaptable robot vehicle in practical use are discussed.
Recently we developed a scale model of a robot vehicle named “Transformable crawler vehicle”. This vehicle has an ability to actively adapt to terrain variations by changing the shape of its crawler units. But its size is too small to run over the actual size stairs. Moreover, it has some points to be improved for practical use. Therefore, we have developed a full scale 2nd-prototype vehicle in order to improve and refine the mechanism.
The volume of this vehicle is about 4.3 times larger than prototype, but the weight is only 2.5 times heavier than that of the prototype. This weight reduction is achieved by using the CFRP, and the structure design improvement.
This machine has an passive adaptability to the terrain variation by ground contact force equarizing mechanism. This mechanism is effective to prevent from slip down when climbing up and down the stairs. It has also turning resistance reducing mechanism by shorten the ground contact length by pushing down the auxiliary wheels. This mechanism can reduce the turning resistant force to 53%. It has also specially designed transmission in order to climb up steep stairs and run fast on flat floor. This vehicle have run on flat surface at a speed of 2.2km/h, and climbed up actual stairs of 39.3° inclination, 203mm step at a speed of 0.44km/h.

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This paper deals with a 6-axis master-slave manipulator system with different kinematics which is considered to have many desirable features for remote manipulation. However, the increased amount of computation for transformation between the two joint coordinate frames requires a long update interval. And the disturbances of the reduction gears cause some undesirable effects. The system in this paper proposes some methods improving the problems; (1) Joints of the master manipulator are arranged along the Cartesian coordinate frame and force-controlled using a force-torque sensor in the handle. (2) The attitude of the hands are described by quaternions which save computational time and communication data. (3) A dual CPU system connected by a serial communication line is used. The system employing these methods realizes smooth operation and precise force feedback.

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