Fujio Ohkawa

A discrete model reference adaptive control system for a plant with input amplitude constraints

This paper considers the stability of a model reference adaptive control system with input amplitude constraints. The conditions given in this paper guarantee the stability of the error between the plant output and the reference sequence. The validity of the theoretical results is demonstrated by numerical examples.

Model reference adaptive control system for discrete linear time-varying systems with periodically varying parameters and time delay

This paper presents a new method for designing a model reference adaptive control system for a class of discrete linear time-varying systems with periodically varying parameters and time delay, Based on Lyapunovs stability theorem, adaptive control algorithms guarantee the asymptotic stability of the error between the plant output and the reference sequence using no anticipative value of the plant output. The validity of the theoretical result is illustrated by numerical examples.

A model reference adaptive control system for a class of discrete linear time-varying systems with time delay

Abstract This paper presents a new method for designing a model reference adaptive control system for a class of discrete linear time-varying systems with time delay. Based on Lyapunovs stability theorem, adaptive algorithms guarantee the asymptotic stability of the error between the plant output and the reference sequence without using anticipated values of the plant output. The validity of the theoretical result is illustrated by numerical examples.

A model reference adaptive control system for discrete bilinear systems

This paper presents a new method for designing a model reference adaptive control system for single-input single-output discrete bilinear systems. The adaptive algorithms proposed in this paper guarantee the asymptotic stability of the error between the plant output and the reference sequence using no anticipative value of the plant output and unknown plant parameters. The validity of the theoretical result is illustrated by numerical examples.

A model reference adaptive control system for discrete multivariable systems with time delays

This paper presents a new method for designing a model reference adaptive control system for multivariable plants with time delays in the input and output variables. An adaptive algorithm guarantees the asymptotic stability of the error between the plant output and the reference sequence using no anticipative value of the plant output and unknown plant parameter. The validity of the theoretical result is illustrated by a numerical example.

A fast template matching algorithm based on central moments of images

This paper presents a new template matching algorithm in which the central moments are used as the matching features and the idea of integral image are used to decrease the time for image matching process. The algorithm also combines coarse-fine two-stage searching methods to effectively solve the problem of finding the peak point of the correlation functions accurately and robustly. It is different with traditional methods in which pixels are used as matching features. Experiment results show that the image process procedure can be finished within 40 ms, which is the rate of image signal send from TV camera for real time object tracking. The results has broad applications in the fields of real time moving object tracking, pattern recognition and the machine vision, etc.

Development of a Sensor System for Outdoor Service Robot

The outdoor service robot, which we call OSR-02, is presently under development intended for cleaning up urban areas by means of collecting discarded trash such as plastic bottles, cans, plastic bags and so on. Additionally, we have developed a novel sensor system for the achievement of the task by this robot; it is constructed with LRF (Laser Rnagefinder), two cameras, and three stepping motors. In this paper, we describe the sensor system and its applications.

Manipulation of a floating object by two space manipulators

This paper deals with manipulation of a floating object by two space robots with manipulators. It is shown in this paper that a total system consisting of two robots and a floating object could be treated as a distributed system, and then a new generalized Jacobian matrix (GJM) is defined. Moreover, it is confirmed that this type of GJM is effective for using adaptive control for decreasing the amount of calculation for the control algorithm.

Digital adaptive control for servo system with unknown nonlinear friction

The authors consider the design of a discrete time model reference adaptive control system (MRACS) for motion control systems with unknown nonlinear friction. From a control system viewpoint, the static and Coulomb frictions are characterized by a nonlinear dead-zone element and constant value disturbance for the control input signal, respectively. The discrete MRACS is considered for a nonlinear system which is a cascade combination of an unknown dead-zone block and a linear dynamic block with disturbance. In order to verify the validity of the theory, the design method described is applied to a servo system influenced by friction. Experimental results show the high control performance of the constructed MRACS and the effectiveness of the proposed method.<<ETX>>

Development of Outdoor Service Robots

The outdoor service robots which we call OSR-01 and OSR-02 are presently under development intended for cleaning up urban areas by means of collecting discarded trash such as plastic bottles, cans, plastic bags and so on. In this paper, we mainly describe the architecture of OSR-02 which consists of hardware such as sensors, a manipulator, crawler structure, etc. for searching and picking up trash. After describing the systems, we show the result of open experiments in which OSR-02 collected plastic bottles in the special zone for robot research and development in Kitakyushu-city