Hybrid Control of a Variable-Speed Peristaltic PUMP

Peristaltic pumps are used for transporting liquids within disposable tubes, and are commonly found in medical devices. The peristaltic pump principle, however, introduces disturbances, thereby distorting the desired rotational speed of the pump. Proportional plus double integral (PI2) control is commonly used to reject these disturbances, but at the cost of deteriorated transient response and robustness margins. To balance these trade-offs in a more desirable manner, in this paper we propose a hybrid PI2 control strategy that allows for reducing the steady-state error while maintaining robustness margins similar to linear PI2 control. Experiments on a representative setup demonstrate up to 45% improvement in disturbance rejection capabilities.