Controlling a System of Linear Drives

A system of linear drives is proposed for process integrated material handling. On a carriage way several vehicles (work piece carriers) should be able to travel with a high degree of independency. The carriage way must allow for curves and for closed paths. A permanent magnet synchronous long stator linear motor with passive, lightweight vehicles is proposed, which does not need any energy or information transferred to the vehicles. The long stator is divided into several sections, each section is fed by an inverter providing individual control of several vehicles. Multiple inverters exchange information with the vehicle controllers via a time triggered inverter bus. A standard PC with additional interface cards is used to control vehicles. During transition between stator segments, the position dependent force is produced by controlling two inverters simultaneously. EMF and thrust force are measured and compared to FEM -calculation results