Study on a high torque output and compact precision positioning system

A positioning system is established and tested for meso machine tools. The design aims to develop practical microscale machine tools, improve the capability in difficult-to-machine material processing, resolve the contradiction between small size and high torque output. In order to maintain a mini volume and in terms of nowadays technology, ball screw driven by AC motor is the only way to achieve high torque output. High grade components and control strategies are employed to grantee the system has an ideal accuracy. At first, the load is analysed and the mathematical models of moving platform and AC motor are setup, then the transfer functions in the control system are calculated. Also, the compact precision positioning system is stacked based on high performance motion control card, 20 bit AC servo motor, high stiffness polish rod linear guideway and precision ball screw. Finally, experiments are conducted, and after an aborative adjustment, the precision positioning servo system can achieve: overall size 200 mm, travel: 100 mm, constant force: 200 N, speed: 5 rpm-2000 rpm, resolution: 0.5 ¿m, positioning error: ± 1 ¿m.