Ethernet-based predictive control of an industrial hydraulic machine

Distributed control networks encounter non-deterministic delays in data communication between sensors, actuators, and controllers including direct feedback control and higher-level supervisor control. This paper presents a strategy, which extends the Generalized Predictive Control (GPC) algorithm to compensate for these data-transmission delays. The present strategy incorporates a minimum effort estimator to estimate missing or delayed sensor data, and a variable horizon, adaptive GPC controller to predict the required future control efforts to drive the plant to track a desired reference trajectory. Action buffers are introduced at the actuators to sequence the future control efforts. The developed scheme is implemented on the dual-axis hydraulic position system of an industrial fish-processing machine.