Design of Optimal Hybrid Controller for Multi-Phase Batch Processes With Interval Time Varying Delay

Abstract

Concerning two dimensional (2D) multi-phase batch processes, a delay-range-dependent optimal hybrid iterative learning control (2D-OILC) scheme is presented. Firstly, the process is converted into a 2D-FM time delay switched system in different dimensions by introduction of state errors and system output tracking errors among batches. According to this model, hybrid iterative learning control is combined with feedback control and a 2D optimal hybrid controller is designed. Secondly, the average dwell time method is adopted to give sufficient conditions for system robust stability in terms of linear matrix inequalities and the upper bound for system's optimal performance index is provided. Besides, the issue of optimal controller design is presented to draw the minimum upper limit of the closed-loop system performance index. The presented control law not only can make the closed-loop system preserving good tracking performance but also ensures its H ∞ performance. Last but not least, the validity of the above strategies is proved by the simulation on an injection molding process. INDEX TERMS Multi-phase batch processes, optimal hybrid iterative learning control, interval time varying delay, average dwell time.

Robust Asynchronous Switching Fault-Tolerant Control for Multi-Phase Batch Processes With Time-Varying Delay

“…This will lead to a mismatch between the model and the controller. Compared with literature [21][22][23][24], the asynchronous switching method proposed in this paper is more in line with the actual situation of industrial application. By calculating the LRT under unstable case, the switching signal is given in advance to match the model with the controller.…”

“…If there are non-repetitive disturbances in the system or batch length is inconsistent, the control effect of iterative learning control method will be greatly worsened. Shi et al [24] proposed a robust predictive fault-tolerant control method for MPBP with time-varying delays, uncertainty and disturbances. This control method can effectively solve the problem of inconsistent batch length in the iterative learning control method.…”

“…This control method can effectively solve the problem of inconsistent batch length in the iterative learning control method. However, the above references [21][22][23][24] adopt the control method of synchronous switching. Due to the influence of some uncontrollable factors in the actual industrial production process, the system state and the controller are difficult to keep in sync, i.e., the model and controller is mismatched.…”

An Optimal Fuzzy Control Method for Nonlinear Time-Delayed Batch Processes

“…Since it is impossible to avoid time delay in the batch process, it is essential to study the stability of the batch process with time delay. There are some research results at present [17]- [23]. For practical systems with disturbances, to devise a control law ensuring the stable operation of the system is only one of the goals; the other is to maintain the system with optimal control performance.…”