Digital Implementation of PID Controller using FPGA for Temperature Control

In this paper, an efficient design scheme for implementation of digital PID controller using FPGA based 8051 microcontroller core is presented as a part of temperature control system. The differential equation includes different controller gains, required to be tuned for desired output response. Usually PID control is much used for second or higher order systems. On the other hand, PI and PD controllers are preferred for first order systems. Here controller is implemented to fulfill the demand of achieving and maintaining the temperature of an Al plate to the desired set point temperature with control precision better than 0.1°C, acceptable rise time and settling time. In implementation load used is a first order system as it has single heat transfer element. Microsemi ProASIC3E family A3PE3000 FPGA development board with suitable ADC and other peripherals is used for realizing the hardware. VHDL is used for code development of differential equation. Microcontroller core is used for configuring and interfacing to peripherals using High level language C. Libero IDE is used to develop, simulate, synthesis and place & route the design.