考虑滑移对摩擦驱动望远镜精度的影响, 提出了天文光学望远镜摩擦驱动滑移动态检测与修正的控制方法。建立了滑移动态检测系统、正压力主动调节系统、负载波动模拟和检测系统。用钢带光栅尺检测动负载位置, 由同轴安装的角度编码器检测主动摩擦轮位置, 根据减速比λ的变化判断主动轮和从动轮之间是否发生了相对滑移。主控单元可编程多轴运动控制器(PMAC)用来实时控制正压力电机进行压力修正并随之修正系统控制算法以提供足够的摩擦驱动力来减轻、消除滑移现象。实验表明: 该方法能及时修正望远镜驱动系统出现的滑移, 从而提高望远镜跟踪精度及可靠性。在最严重滑移的情况下, 系统可在100 ms内判断出滑移, 74.2 s完成校正并恢复望远镜的高精度跟踪。此方法既可用于单点摩擦驱动也可用于多点摩擦驱动, 能够有效解决非线性干扰带来的滑移问题。

As slippage influences the tracking error of a telescope with friction drive, a way to detect and correct the slippage of friction drive was proposed for astronomical optical telescopes. A slippage dynamic detection system, a normal pressure active adjustment system, and a simulation and detection system of load fluctuation were established. The position of dynamic load was measured by a tape encoder and the position of active drive wheel was measured by a coaxial angle encoder. Then, the slippage was detected by transmission ratio. The Programming Multiple Axis Controller(PMAC) was used as a main control unit to control the normal pressure motor to adjust pressure and the control algorithm was also modified. By above way, enough friction drive force was obtained and the slippage was alleviated or eliminated. Experimental results indicate that the way can correct the slippage in time, improve the tracking precision of the optical astronomical telescopes and increase the stability of the drive system. In the most severe case, the friction drive system can resume the high accuracy tracking by detecting the slippage in 100 ms and completing the correction in 74.2 s. The method can be used for both single-point friction drive and multi-point friction drive and can solve the slippage caused by nonlinear disturbance.