The Research On Multivariable IMC-PID Control Algorithms

PID control technology is used widely in industry, but there are time-delay and coupling in processes when industry become complexity, PID control will not be satisfied the process control needs. Internal Model Control (IMC) is an advanced control technology based on model, which design simply, and has strong robustness and good performance in time-delay process, especially in error models. If it can be combined the advantage of IMC and PID, then it is not only satisfied complexity process need, but will be used splendidly in industry. It is analyzed and researched multivariable IMC-PID control algorithms in this thesis, and the fruits as follow:1. It is introduced single-variable IMC technology and design of IMC controller, and analyzed and compared some time-delay approximate ways. It is introduced two ways of IMC-PID tuning, and exported the equations of IMC-PID controller parameters for first order time delay and second order time delay processes, and then simulated and compared. And it is introduced genetic algorithm and optimized IMC controller of process; 2. It is introduced multivariable control system theories and introduced three ways of computing RGA. And then introduced some decoupling ways about process decoupling and controller decoupling and simulated. All IMC controllers are optimized by GA;3. All decoupler have not good performance in bad models. It is developed a common decouple algorithm to be used in IMC decoupler, and simulated in open-loop and closed-loop.