Study On Hardware Implementation Of Digital Controller Based On FPGA

Control technique has been widely applied in various fields, and analogy control technology and digital control technology are the two most leading techniques currently. Compared with analogy control technology, digital control technology has high accuracy and good stability. Consequently digital control is developing swiftly.Current digital control technology mainly uses computer or microprocessor as the controller, and the control algorithms of the controller based on computer or microprocessor are mainly implemented by the program, which means it has bad performance of real-time, control period, capacity of resisting disturbance and reliability and so on. This paper introduces a digital controller based on FPGA with the algorithm implemented by VHDL and downloaded into FPGA and implemented by hardware eventually. Therefore, it has the advantages of anti-jamming, short control period and good real-time. But the operational precision is the main problem taking FPGA as the digital controller. So floating point operation should be introduced to guarantee the accuracy. The paper deals with the representation of floating point and its implementation of addition, subtraction, multiplication and division in FPGA.Systematic area and speed are the two important facts in system design based on FPGA, which should be optimized to increase the speed and reduce the system cost. Several kinds of optimization of speed and area are studied in this paper.Hardware implementation of the PID control algorithm is taken as an example to introduce the design method of hardware digital controller based on FPGA.