Application Research On Generalized Predictive Control

In this paper advanced process control (APC) algorithm is proposed in order to overcome the nonlinearity, large time-delay and time-varying of the reactor temperature control in Beijing Atofina chemical engineering control system. APC is some control strategies that have better control effect and higher precision than general control. Generally there are two ways of applying advanced process control algorithm in industrial process control. The first is to develop APC software based on IPC or embed APC program into configuration software running in upper computer. The second is that industrial control developing companies develop APC algorithm modules in their hardware equipments. In the case of the control system adopted by general production equipment, for the large computation of APC algorithm, it is hard to realize APC algorithm computing by PLC or lower controller, so the task of realizing the APC is left to upper computer and the control signal computed by using APC algorithm in upper computer is collected by lower controller.Generalized predictive control (GPC) is one of the widely applying APC algorithm, which has shown its characteristic of overcoming time-varying, large time-delay and nonlinearity remarkably in industrial field. Because of a large amount of computation of elementary GPC algorithm, an improved GPC algorithm is presented in this paper, analysis of stability and robustness is given respectively, simulation studies show that the improved algorithm can obtain better control effect in both the response time and the steady-state performance than conventional GPC algorithm.In this paper through analyzing the control system configuration of the Beijing Atofina chemical engineering deeply, a strategy of the secondary developing RSView32 is proposed, and the way of using the Visual Basic Editor to embed the improved GPC algorithm into RSView32 is given, and non-disturbance switching between upper computer and lower controller is realized when fault happens in upper computer. Simulation studies show that the scheme has fast tracing response and can overcome the large time-delay and nonlinearity.