Fractional order internal model control strategy for inverse response time delay process

A double-loop control structure based on IMC is proposed for the inverse response time delay process. In order to suppress the input of the interference signals, an anti-interference controller is provided in the inner loop, in the form of proportional derivative. The internal model controller of the outer loop adopts fractional order form, it is used to track the set-points. The parameters tuning of PD controller is obtained from the Routh-Hurwitz stability criteria and the Maximum sensitivity function. The proposed control structure includes four adjustable parameters, they are proportional parameter, derivative parameter, the adjustable time parameter and fractional order parameter of the low-pass filter. Through a large number of simulations, an adjustable range of four adjustable parameters are given. The performance of the proposed structure is assessed using ISE, IAE, and ITAE. Simulation results demonstrate that the proposed method has good performance in both set-point tracking and anti-interference. Compared to other methods it has better control performance.