Teruyuki Maeda

Control of cutting torque in the drilling process using disturbance observer

In the drilling processes of machine tools an increase of the drilling speed is usually required, but it often leads to breakage of the drill due to the excessive torque. Thus it is necessary to measure and control cutting torque in real time. In this study a new sensorless control system is developed of cutting torque irrespective of drill wear and the material of target work-pieces. The authors (1994) proposed an estimation method for the cutting torque using a disturbance observer. This paper is concerned with a sensorless PID torque control system for the drilling process based on the estimated torque information. Experimental results demonstrate the effectiveness of the proposed method.

Fuzzy control using knowledge acquired from PD control

The authors propose a design method for a fuzzy controller by using knowledge acquired from proportional derivative (PD) control. Two types of fuzzy controller are presented. One is identical and the other is approximately equivalent to the PD controller. The mathematical model of the fuzzy controller is derived and the properties of the output of the fuzzy controller are clarified. A design method of the fuzzy controller which satisfies two specifications, the dynamical properties of the rising and settling regions of the response, is presented using the mathematical model.<<ETX>>

Learning control of an inverted pendulum using neural networks

Several problems in control using neural networks are pointed out, and a method for using some knowledge about the properties of the controlled object is indicated. As an example, a hierarchical control system of an inverted pendulum using a neural network is proposed. The controller consists of a pendulum part driven by the neural network and a cart part generating the virtual signal. As a result, the neurocontroller can be constructed easily and can be learned rapidly. The effectiveness of the control system has been confirmed by simulation and experimental results.<<ETX>>

Force Control of Robot Arm Using the Virtual Environment Model

Abstract A new design method of force control system with consideration of the approach to the environment is proposed. The force in constraint space can be controlled and the robot arm move with constant velocity in free space, so the proposed method does not require the change of controllers in the transition from free space to constraint space. And to reduce the impulsive force at collision, the approaching velocity is controllled by introducing the concept of the virtual environment model.