A non-contact laser displacement meter based on the principle of optical triangulation is applied to measuring distance or displacement to an object and its shape. A laser diode is used as the light source and a position sensitive device as the light spot detector. A laser displacement meter of type MD-1211 with high accuracy has been developed, which is an intelligent equipment with a microprocessor. In this paper the errors caused by variable amount of receptive light and a light spot image on the position device are investigated. A control technique of laser output for type MD-1211 is proposed. In the new technique, the output intensity of the laser diode can be rapidly controlled within the range of 100 times of the minimum output by the microprocessor. A position sensitive device detects the center of light intensity on itelf. To reduce the error caused by diversion of the light spot, a device for design and adjustment of the receptive optical geometry is proposed. The overall structure and the specifications of type MD-1211 using the proposed techniques are described. Their usefulness are verified with several experimental results.

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Exact measurement of heaving, rolling and pitching of ship is important in exact searching for the seabed patterns by a sonar. From this point of view, the authors developed before an automatic measurement system which measures the ship attitude by using three servo-type accelerometers appropriately located on the ship. It generally required, however, much computational time in getting the optimal estimate. This is because the ship attitude signals appear in the accelerometers in a strongly nonlinear form.
The present paper proposes a new automatic ship-attitude measurement system which promises a stable, easy and higher accurate measurement of the ship attitude by using four servo-type accelerometers appropriately located on the ship. For realizing it, adequate linear combinations of the four sensor outputs are considered to separate the three attitude signals from each other.

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A measurement system based on color image processing was developed to obtain simultaneously both velocity and temperature distributions in thermal flow fields. Flow visualization was accomplished by the use of thermosensitive liquid crystal tracers. The visualized image gave both flow and temperature patterns.
A modified correlation method was used to obtain the velocity vector distribution. In addition, an algorithm for the calibration of color to temperature is presented to obtain the temperature distribution.
An unsteady natural convection, which is a simple unsteady thermal flow, was chosen to confirm the appropriateness of this technique. Consequently, the flow and temperature fields were measured simultaneously and it was confirmed that the quantitative results agree with a typical pattern of unsteady natural convection.

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Following the idea of Huber's maximum likelihood-type estimator (M-estimator), Polyak and Tsypkin proposed a robust recursive identification method analogous to the recursive least squares method. They seek for an estimator minimizing the maximum asymptotic variance over some convex class of innovation distributions. However, they did not discuss its convergence properties throughly because of the difficulties due to the introduction of some approximations in the identification method and correlations between observations. In this paper, we discuss the convergence properties of the robust recursive identification method for linear stochastic models from the viewpoints of ODE approach and martingale convergence theory. We present two convergence theorems for the robust identification method.

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A selection method of time-variable forgetting factor is presented for least squares parameter estimator. The method is based on the monitoring of the statistical behavior of the residual. Then the forgetting factor is selected so as to adapt the residual variance caluculated from the estimator to the acutual one. AIC is used for the monitoring the statistical behavior of the residual.
Bounds on the time evolution of estimation error are discussed. It is also shown that the proposed method gives acceptable performance in the numerical experiments.

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In this paper, we present design methods for finite-dimensional adaptive controllers of general distributed-parameter systems using the theory of variable structure systems (VSS). First, we state a new basic design method. Secondly, we propose two kinds of design methods in order to improve convergence characteristics, i.e. to perfectly achieve model following in an arbitrary finite time. Furthermore, we show that control systems with these proposed design methods can completely reject any bounded input and output disturbances in an arbitrary finite time. Main characteristics of the others are the globally uniform boundedness of the sliding mode and the construction of two (or one) dimensional adaptive controller. Finally, we make sure of the effectiveness of our proposed methods using a simple example.

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The rapid progress of digital computers enables us to simulate complex and large-scale systems. Furthermore, many control techniques have been proposed in order to improve the control performance for discrete-time control system. However, since these control techniques are too complex, it may be difficult to apply them to real plants and understand a physical meaning of control parameters included in these control strategies. On the other hand, PID and I-PD control methods have been used for several control systems up to now since they have simple control schemes. Therefore, it is necessary to consider control methods with PID and I-PD control structures in discrete-time systems.
In this paper, we construct a discrete-time control system by using model matching method. In the discrete-time control system we can not construct the model matching control system due to time-delay element. Therefore, we insert a pre-compensator in the usual I-PD control system and construct a new I-PD control system for the extended system. Furthermore, we consider an adaptive tuning method of PID gains. Finally, we illustrate some numerical simulation results to show the effectiveness of the proposed control method.

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A two-degree-of-freedom optimal servosystem for a constant reference signal is proposed using the LQ optimization technique. First, an optimal tracking system with no integral compensator is designed for a given model of the plant and a specified perform anceindex. The obtained control law is applied to an augmented system composed of the plant and an integral compensator. Then, an additional state feedback is introduced at the output of the integrator to cancel the integral action for reference signals if there is no modeling error of the plant and no disturbance input to the plant. When the modeling error or the disturbance input exists, the integral effect appears. The gain for the integral effect is selected so that the total control system is optimal for a performance index. The system has a free parameter which can be used to tune the effect of the integral compensation.

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This paper investigates the ripple phenomena in digital repetitive control systems, where the plant to be controlled is a continuous-time system while the controller to be designed is a discrete-time system and reference and/or disturbance inputs are periodic. We can see from the Internal Model Principle that the steady-state error is zero at sampling instants if we implement a model of generator for the periodic signals in the feedback loop and stabilize it. However, there may exist undesired phenomena or ripple behaviors between sample instants.
It is shown that the larger ripple is mainly caused by the larger level of steady-state control input based on the steady-state analysis. We introduce an index for the level of the ripple which is related to the level of the steady-state control input and uniquely determined by discretized plant. We also proposed a design method using asynchronized sampling for the attenuation of the ripple.

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Configuration space method is one of the general collision avoidance method for robot manipulators. Basing on the graph search algorithm, the configuration method is free from the dead-lock problems which may arise in the potential method. However, the number of nodes in the graph to describe the configuration space grows exponentially, correspondingly to the dimension of freedom of manipulator. Therefore, some methods to prevent from computational explosion for high d.o.f. manipulator is required. We apply a heuristic graph search algorithm for searching. The evaluation function for a search is defined by two sum of a distance between the links of a manipulator and the middle plane among obstacles and a distance between the end-effector and the subgoal on a desired trajectory. Taking into account that the computational cost for heuristic graph search algorithm grately depends on the shape of configuration space, we introduce subgoals on desired trajectory of end-effector. The introduction of subgoals reduces trivial search and lessen the computational cost for searching in the complicated configuration space.
The effectiveness has been verified by simulation studies.

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One of the problems in image recognition is how to acquire the 3-dimensional range data on the designated regions in the scene to extract the features, such as 3-dimensional shape and orientation of an object in order to reduce the processing quantity of information and simplify the recognition procedures. This paper proposes a method in which the visual feedback principle is introduced into the procedure of acquiring the 3-dimensional range data on the specified area in the scene. This method is based on the image recognition technique and the active measurement of 3-dimensional range data. The inputs of the visual feedback control system are referred to as the picture cells in a specified window (attention window) on the image. The attention window is determined according to the pattern recognition results. The outputs are referred to as the positions of the laser spot in the scene. As soon as the position of a picture cell in the attention window is selected as the input, the spot of the laser range finder will automatically approach the point corresponding to the input in the scene until the output position on the image overlaps onto the input position. Then, the 3-dimensional coordinate of the point in the scene is acquired according to the triangulation. In this way, all the 3-dimensional range data of the specified area in the scene are input consecutively for shape recognition and for extraction of object features.

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Tracking signal detection and radial tracking control by a sampled servo method with servo marks are studied with the aim of achieving a highly-accurate radial tracking control system for a flexible optical disk drive. The servo marks on the flexible disk surface are formed as light and dark patterns by a photographic technique. Calculations show that the position signal level for square servo marks is about 20% larger than for circular marks. The detection error due to clock jitter (60ns) for square marks is only half or one third that for circular marks. The detection error is mainly caused by the medium noise, after analyzing the detection error factors.
The results of this study show that a flexible optical disk rotating at 900rpm can achieve stable radial tracking control with a servo error of less than 0.2μm when the track pitch is 2μm.

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A parallel reasoning process is studied, which is executed by intelligent sensors, each of whom is a member of a distributed sensor network (DSN). DSN is a new notable approach to situation assessment, that involves the acquiring and integrating of local information sensed from the world in order to produce a global interpretation. In this paper, each intelligent sensor has its own knowledge, a qualitative model about its concerning world and general law on the event evolution, both of which are utilized for predicting a future evolution after an observed event known by the local information obtained. Each of sensors generates a tree structure, qualitative evolutions after that event, by transitting states on that model to meet constraints, representations of general law. A tree structure, partial interpretations of a local information, involves branches caused by incompleteness of that information, lack about details. In order to integrate those interpretations into global ones, sensors exchange their own tree structures to prune branches which are inconsistent under global perspectives.

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We consider the Stackelberg problem composed of a single leader and several followers which are interacting but cooperative mutually. Then the followers choose an unique solution from the noninferior solution set of the multi-objective optimization problem by mutual agreement. On the other hand, under uncertainties regarding the followers' agreement, the leader makes an optimal decision against the case where the worst noninferior solution for leader's objective function might be chosen from the noninferior solution set of the followers. That is to say, let the leader adopt the min-max criterion.
In this paper, we call such a decision “the min-max type Stackelberg strategy for the multiple objective problem”, and the problem solving such a decision is formulated. And then, in the case where the min-max type Stackelberg strategy is adopted in the multiple objective resource allocation problem, we propose an algorithm to obtain the strategy as the optimal resource allocation.

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Either noises or similar word syllables deteriorate the speech recognition when the methods use only voice or sound data. Additional information applied in lip-reading may improve the recognition under such conditions.
This paper has proposed a system of speech recognition for some finite number of words under noisy background. The system, which has both an X-Y tracker and a microphone, can detect sounds and positions of lip movement. The X-Y tracker processes the visual images and sends a pair of the X-Y positions in the coordinate, which enables us to obtain the lip movements in real time without some complicated tasks to the main computer. The pair of the marked position near the lip in addition to the speech are inputted to form a pattern for speech recognition. The patterns of the voice synchronized with the X-Y positions of the lip movements are compared to the standard patterns to recognize the spoken words. The weight coefficients to change the importance of visual or voice data are introduced and selected to get the best performance for some registered words.
The experiments were carried out to prove that the proposed system can improve the recognition rate in the presence of continuous noises. The results has shown about ten percent improvement under signal noise ratio as 35dB, and about 20 percent under the signal noise ratio as 26dB.

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Two methods for the smooth and rapid insertion of a round peg and hole assembly by reducing the insertion forces are proposed. One is based on the minimum insertion force with known insertion angle between peg and hole, and the other is a method to reduce the friction coefficient along the peg and hole axes by rotating peg.

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