Minimum Electrical Energy Use in a Multi-Actuator System

Many modern industrial systems include more than one electrical motor; for example, cutting tools and 3D printers include positioning systems of linear actuators driven by motors. Reducing energy consumption is an increasing priority for all sectors including manufacturing industries. Conventionally during the off-cut operation, positioning systems are controlled in either rapid positioning mode or linear interpolation mode. In both these modes, motors are controlled independently from each other, leading to increased energy consumption or a rise in operational time. In this paper, a novel method of energy use minimization by controlling drives with respect to each other is presented. It utilizes the Model Predictive Control (MPC) technique to identify the optimal state trajectory. This trajectory is used as feed-forward to the classical cascaded controller. For the particular case studied, experimental results show 13% and 8% efficiency rises compared to the rapid positioning and linear positioning modes respectively. The technique is validated on a dual brushed DC motor system.