Development Of Portable PID Tuning Instrument Based On Multivariable

PID controller is the controller which is used widely in industry control field, PID parameter tuning problem has always been one of the problems which plagued technical staff in the actual engineering, so the parameters tuning of PID controller has become the hotspot in present research.Based on the analysis of the situation on PID parameter tuning in China and abroad, the paper takes a PID control system with two-input and two outputs for example, and gives the MATLAB simulation diagram. Based on step response model identification methods in frequency domain, the paper compares the Nyquist response curve of the identification model and the original model, and proves the method is effective.Based on the advantages and disadvantages of the various multi-variable parameter tuning methods, RGA offset factor method was applied to portable PID parameter tuning instrument based on multi-variable for tuning. Respectively ZN, ISTE and the RGA offset factor method were simulated, and the simulation results showed that RGA imbalance factor method is more effective.In detail the paper introduces to design of the function of portable PID parameter tuning instrument, software and hardware design of the system are completed with MSP430F169 as the core control unit.