Linear drive system for combined transportation and processing of materials

Long stator permanent magnet synchronous linear drives with passive, lightweight movers (vehicles) are proposed for material handling systems which require high dynamics. In such application the stator is divided in processing stations and transport sections. Inside the processing stations high quality speed and position control of the vehicles is necessary, imposing the use of position sensors, whereas in the transport sections sensorless control is used. In this paper the control of a vehicle inside and outside the processing stations is being studied, including the transition between processing stations and transport sections. Due to mechanical constraints, there are gaps in the winding arrangement between consecutive segments of the machine, which means that the electromotive forces (EMFs) of two consecutive segments can have an arbitrary phase difference, providing additional challenges, especially in the sensorless control.