Fuzzy-PID Controller And Its Implementation Based On FPGA Of Micro DC Motor

Phased array radar needs to change the phase of elementary antenna in real time to satisfy the beam pointing of array antenna in the processing of beam scanning.Equipped with micro motors,phased array radar could change the phase of elementary antenna.With the development of high frequencies,it’s necessary that micro motors have the ability of quick response,high accuracy and small size.Micro DC motor which has small size,light quality,high accuracy,simple control and excellent start and stop performance can be a good driver unit.There have been imperfections as follows in the phase controlled system of micro DC motor with using classic PID controller usually.1)It’s difficult to satisfy the needs of fast response and high accuracy when the micro motor adapts same parameters.2)Due to the differences of configuration parameter and characteristic parameter between micro motors,it’s hard to adapt same parameters in different system.Aiming at solving these problems,the paper study the Fuzzy-PID controller of micro brush DC motors based on FPGA which can be applied to phased array radar with high frequency.In order to solve the current discontinued question about small inductance,this paper studies the math model and presents some viable solutions.Combined with domestic and foreign solutions,this paper chooses increasing the switch frequency,string into inductance and reducing bus voltage to simulate.In order to solve the problems existing when using the classical PID control,an adaptive fuzzy PID control algorithm is introduced and a simulation model of micro DC motor with single closed position control is established.This paper compares and analyzes the performance when it adapts classic PID controller and Fuzzy-PID controller in different working conditions.Simulation shows that comparing with classic PID control,the overshoot is reduced by 8.33% and the response time is reduced by 30 ms at the same position when adapts fuzzy PID control.This scheme has the characteristics of fast response,high accuracy and strong robustness.This paper designs a fuzzy PID controller IP core based on FPGA,which described in Verilog HDL using pure hardware language.Depending on different function,the IP core can include Avalon bus interface module,PWM generating module,QEP module and Control algorithm module.The Control algorithm module is the core,which can modulate PID parameter,calculate duty and enable PWM module.Finally,based on Quartus II platform and Modelsim software,this paper simulates the module and IP core.Simulation shows that the execution order is correct and the calculations meet the expectations.Experimental platform with single-axis and two-axis are built of micro DC motor and the measured data and curve could be analyzed.Experiment shows that the overshoot is reduced by 14.33% and the response time is reduced by 30 ms at the same position when adapts fuzzy PID control in single-axis system and the two motors can complete the instructions in parallel and without interference.This scheme can modulate PID parameters in real time and has the characteristics of fast response,small overshoot,strong robustness and high accuracy.