Motion Control for X-Y table of a low-cost Nano-CMM
A motion control method for X-Y table of a nano Coordinnate Measuring Machine (nano-CMM) is proposed in this paper. The main work includes, signal process, velocity calculation and control, touch and reading of the probe, simplification of the hardware. A velocity control scheme is studied to achieve low and stable velocity while driving the X-Y table of the nano-CMM. The signals of an optical encoder are used as a velocity feedback. The X-Y table is driven by a ultrasonic motor called HR2 which has three different driving mode: the AC mode in continuous motion for the long stroke, the GATE mode to drive the motor in low velocities the short stroke, and the DC mode in which the motor works as a piezo actuator mode. In this paper a new PID control based on Back Propagation Neural Network (BPNN) is used in AC mode and GATE mode, which shows more robustness than conventional PID control scheme. Some supplementary methods both in hardware and software are used to guarantee stability of the system. Experiments show that the velocity can be controlled to 0.5mm/s in AC mode and 500nm/s in GATE mode. With this control scheme, a surface scan method with a non-contact optical probe is proposed. An application of a innovative touch-trigger probe with this motion control scheme is also discussed in this study. Some applications of this motion control scheme are presented in this paper.
nano-CMM velocity control AC mode GATE mode BPNN low-cost
Ye-tai Fei Fang Cheng Hao-jie Xia Wei-li Wang
School of Instrumentation,Hefei University of Technology,Anhui,China
国际会议
成都
英文
2007-11-19（万方平台首次上网日期，不代表论文的发表时间）