A digital PID controller for real time and multi loop control: a comparative study

We introduce in this paper a comparative study for three digital PID (Proportional+Integral+ Differential) controller architectures. So designed this PID can be used for real time applications where the command speed is a crucial parameter. For multiloops systems this controller allows tuning parameters calculations in the minimal time delays. The implementation of the digitized PID algorithm in one FPGA (field Programmable Gate Array) is designed as a specialized computation processor. This FPGA PID circuit can be embedded into a process calculator (PLC, Microcomputer, and microprocessor board...). This hardware implementation can be implemented in three different architectures: serial, parallel or mixed. In all cases this kind of electronic implementation has a much faster response than a software one. The digital PID so designed is based essentially in architectures including state machines, multipliers, adders and some others logic circuits