Error based switch control strategy for a class of industry processes with long time delay

This article proposes a switch control strategy between a generalized predictive control (GPC) algorithm and a typical PID one in order to reduce computational load and obtain better control performance simultaneously in the control of a class of industry processes with long time delay. This switch strategy is scheduled by the absolute error from a process output value to its setpoint value. If the error is larger than a given threshold, a GPC procedure is triggered off to make the process output reach the setpoint as quickly as possible. Otherwise, a PID control algorithm is performed to reduce computational load. The simulation study shows that the better control performance can be gained for a process with large dead time by performing the GPC algorithm only few times in the whole simulating period. Since the PID algorithm is performed in the most simulation time, the computational burden is effectively reduced.