Optimal force control of a permanent magnet linear synchronous motor with multiple shuttles

Abstract

Using permanent magnet linear synchronous machines for transportation tasks offers a higher flexibility in production plants compared to conventional conveyor solutions. In this context, passive transportation devices (shuttles) with permanent magnets are commonly used. When multiple shuttles are operated in close vicinity, disturbances due to magnetic interaction can occur. To allow for high-speed operation of the motor with high position control accuracy, these coupling effects must be considered. This paper presents a model-based control strategy that is based on a magnetic equivalent circuit model which is able to describe the nonlinear magnetic behavior at low computational costs. A framework is derived for the model calibration based on measurements. An optimal control scheme for the multi-shuttle operation is derived that allows to accurately track the desired tractive forces of the shuttles while minimizing the ohmic losses at the same time. The control concept is experimentally validated on a test bench and compared to a state-of-the-art field-oriented control concept typically used in industry.