Implementation of motion control technique for stepper motor translation stages in online detection system

In the process of microtarget assembling, the geometrical parameters of the microtarget need to be measured in real-time by the online detection system with four-axis linkage. So the moving performance and positioning accuracy of every motorized axis are crucial to the measurement. This paper proposed a new motion control technique for linear translation stages with stepper motor. The control algorithm was realized on field programmable gate array (FPGA) and digital signal processor (DSP), and met the high-efficiency and high-precision measurement requirements. An efficient and optimized speed control performance was achieved by using a method that was based on speed-difference driving and speed-table supplying, and a high-precision, closed-loop positioning control performance which has an error less than +0.3μm was achieved by using a method that was based on position feedback, position-window restriction and time-window restriction.