Probability Based Stochastic Iterative Learning Control for Batch Processes With Actuator Faults

Abstract

This paper proposes a new stochastic composite iterative learning control for batch processes with actuator faults that happen with a certain kind of probability. The main contribution lies in the fact that stochastic control theory is used to analyze the stability issues and consider controller designs of batch processes with actuator faults that happen under various kinds of probability, which paves the way for reliable control theory. Firstly, the batch process is represented as a system with stochastic uncertainty for iterative learning control design; and with the state and output error, it is further treated into a two dimensions (2D) Rosser system with stochastic errors. Using such transformation, the iterative learning control design is transformed into the updating control law design. Secondly, 2D Lyapunov stochastic theory is used to design the controller with actuator faults under various kinds of probability, together with the stability results of the control system in terms of LMI conditions. Finally, the proposed method is tested on the injection molding process to demonstrate the effectiveness.

Iterative learning fault-tolerant control for discrete-time nonlinear systems subject to stochastic actuator faults

“…The mechanism of actuator faults in this paper is different from that in Wang and Li (2019) and Wang et al (2020), although the faults also occur in random manner over there. In those scenarios, the actuator faults occur independently at different time instants in every learning cycle while the failure patterns at the same time instants in different cycles are not involved.…”

“…Generally speaking, there mainly are three types of faults in the process of systems operation, named, actuator faults, sensor faults, and other process components faults (Patton, 2014; Wang and Li, 2019). For a practical dynamical system, the actuator works well and can successfully complete the established control objectives.…”

“…Therefore, how to design an ILC algorithm according to the occurrence probability of faults becomes one of the significant issues. Recently, the topic has attracted the attention of researchers (Wang and Li, 2019; Wang et al, 2020). However, there are still some shortcomings remain to be improved.…”

Design of a Switching Control Strategy for Time-Varying Delay Batch Processes Using Fault Probability-Based Average Dwell Time Method

“…In addition, a system may age in operation and even fail to perform normal operation. Therefore, when a system has delay and faults (faults fall into partial failure faults, complete failure faults, and stuck faults; stuck faults are not taken into account in this work, and partial failure faults are elaborately described in our previous work, and briefly described in Theorem 1, which will not be described at length any longer), the system’s actual input, u F ( t , k ) will not be equal to u ( t , k ), that is, u F ( t , k ) ≠ u ( t , k ). Faults happen in the system in a stochastic way.…”

“…When a partial failure fault occurs, the controller should be switched to reduce the waste of resources and a reliable controller should be used to solve the current shortcomings. This part has been studied in depth in ref and will not be repeated here.…”