Design and implementation of PID controller based on orthogonal wavelet filter-banks in FPGA

Abstract

This paper analyses the performance of a PID controller for a servomotor system which is based on Wavelet as opposed to conventional PID controller. First, the orthogonal wavelet filter bank has been obtained. For decomposing the error signal(difference between reference and actual speed of servomotor system) at different sub-bands, wavelet filter bank is used. These sub-bands have been scaled by selecting optimized gains in order to minimize the error. After adding the resultant sub-bands together and the control signal is generated for the servomotor system. The simulation results show the superiority of the wavelet-based PID controller over existing PID controller for different conditions and also the Multiresolution (MRPID) controller is implemented on FPGA and the filter characteristics is compared with the MATLAB simulation.