Compensation-Signal-Based Dual-Rate Operational Feedback Decoupling Control for Flotation Processes

Abstract

The flotation industrial process is a strong nonlinear and coupling, multivariable cascade process with device and operational layers structrue. To address its operational control problem, this paper describes two layers nonlinear dynamic characteristics and disturbances as the previous sample unmodeled dynamics and its change rate and proposes a compensation signal based dual-rate operational feedback adaptive decoupling control approach. First, a device layer controller is designed consisting of a controller driven model, a PI controller, an unmodeled dynamics compensator (UDC) and an unmodeled dynamics change rate compensator (UDCRC). Then, the device layer closed-loop system and the operational layer system are unified in the same timescale and hence a controlled plant model is obatianed. A system identification algorithm is proposed to obtain the parameters of this model. With these parameters, an operational layer controller is designed consisting of a controller driven model, a PID controller, a feedback decoupling controller, UCD and UDCRC. Finally, convergence proofs of the proposed identification algorithm and the closed-loop system stability analysis are given, and emulation compared experiments in a hardware-in-the-loop system are used to verify the effectiveness of the proposed approach.