Data-based iterative learning control for multiphase batch processes

In order to cope with the problem of the robustness conditions dependence on system parameters information, this paper investigates a data-based iteration learning control (ILC) for multiphase batch processes with different dimensions and system uncertainty. Firstly, by minimizing the residual between the actual subsystem output and the approximated subsystem output, a gradient-type approximation law is designed to approximate the system lower triangular parameters matrix and initial state. Secondly, by minimizing the approximated tracking error between the desired trajectory and the approximated output, a data-based ILC is constructed in an interactive mode with the approximation law. Finally, the boundedness of the approximation error of the real system parameters from the approximated parameters is derived by means of vector norm theory, while the unconditional robustness of the proposed data-based ILC is proved. Simulation results illustrate the effectiveness and practicability of the proposed data-based ILC.