Study Of A Fuzzy Controller With Generalized Membership Function In Vibration Control

Vibration and noise is the response of any engineering structure when the structure is acted by an outer power or interference source. The problem of vibration is becoming more and more distinct along with the high-speed-development of industrial technology. Vibration will be disadvantage not only to the normal work of a structure, but also to the life span of the structure or even destroy the instrument within it. Except debasing the performance of mechanical system, vibration will badly endanger people' s health. So we have to control it. Vibration control is aimed at restraining harmful vibration in virtue of various dynamics fundaments base on objects' character, working environment and control requirements. In this paper, we focus on the problem of vibration control of a cantilever beam with Active Vibration Control Method. Active Vibration Control (AVC) is a method of compensating the vibration with "man-made" vibration by importing outer power into the controlled system. In addition, it is piezoelectric film, which is light, less power and easy to control, that we use as sensors and actuators in the cantilever beam. Piezoelectric sensors and actuators are adhered to the base material directly, and compose the active vibration control system along with the single chip.Fuzzy control, a control method based on linguistic control rules, has achieved great success in real application, because it doesn' t need precise model of controlled objects, and make the control strategy easy to understand. There are still many problems, however, in design of fuzzy controllers. It is one of the problems that many subjective factors revolved in the selection of fuzzy variables' membership functions, because of insufficientknowledge beforehand about objects. We introduce concept of the general membership function into design of fuzzy controller in this paper. Furthermore, we design a fuzzy controller based on the general membership function, and optimize the general membership functions' parameters with genetic algorithm. Then we have a simulation experiment.At last, after introducing the design of an Atmel 89C51 single chip system and some circuit, we have an experiment of active vibration control of cantilever with the fuzzy controller based on the general membership function we designed, and the cantilever beam is equipped with piezoelectric sensors and actuators. The software is developed with C on the WAVE E2000 platform. Good effects also prove the feasibility of the design method of a fuzzy controller with the general membership function.