A robust and low-cost linear motion system for precision manufacturing automation

Most advanced manufacturing processes require linear motion for material transfer, packaging, assembly and electrical wiring. To achieve precise linear motion, most of these high-performance manufacturing machines use X-Y sliding tables with permanent magnet rotary motors and rotary-to-linear couplers. Though this method is the most widely used, it has disadvantages of low accuracy, complex mechanical adjustments, high cost, and low reliability. This paper describes the use of variable reluctance technology to construct a novel linear direct-drive actuator system for high performance motions in manufacturing automation. The proposed actuator has a very simple structure and it can be manufactured easily. There is no need for magnets and no limitation on the travel distance. The actuator is extremely robust and can be used in hostile environment. A novel control method, using cascade control and force linearizing is developed and implemented for precise motion control of the actuator. Preliminary results of the motion system indicate that the system has fast response with good accuracy