Fuzzy Bang-Bang Controller For Optimal Time And Minimum Chattering Servo System

• Main Authors: Der-Hwa Wang, 王德華
• Other Authors: Tsong-Liang Huang
• Format: Others
• Language: zh-TW
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/78907320303233477155

碩士 === 淡江大學 === 資訊工程研究所 === 81 === In modern industrial control application there are many situations in which the control objective is to move actuator from one point in space to another and to settle as quickly and accurately as possible at the point, while the control effort is kept within some limited value. Therefore , it is usually necessary to design two tracking controllers for the sysetm to accomplish large movements. During the first stage, when the actuator is undergoing large accessing motion, the control algorithm may be designed by using the classical time optimal control with constraint the control effort. As the actuator comes close to target position , the controller is switched to a regulation stage, The method is to eliminate the chattering and steady state error common to the classical time optimal Bang-Bang controller. In this paper a new method for nonlinear saturated control is proposed. The method is based on the classical time optimal Bang-Bang control. By preserving the time optimal characteristics of the classical Bang-Bang control, the chattering and steady offset problem will be avoided by the new method. A fuzzy controller is utilized for the controller implememtation. The method is inherently robust. The proposed controller "Optimal Path Estimation Method (OPEM)" emerges from the concept of sucessively suppressing dimensions of the state space and decreasing control effort value. The feedback signal for the fuzzy logic controller is based on the distance from the present state to the switching curve along the optimal trajectory, and from the switching curve to the original point of phase plan. The advantages of proposed method over traditional Bang-Bang control method are illustrated by numerical simulations of a servomotor system.