大口径机械快门的设计与研制

Design of Large Aperture Focal Plane Shutter

针对大口径大视场望远镜的需求,设计了一种用于大口径望远镜的机械快门,其通光口径可达φ200mm,具有快速启停,定位准确,不同倾角下两叶片同开同闭等特点。机械结构设计中采用同步传送带和步进电机作为其传动装置具有平稳、速度快、定位准等特点;步进电机的控制、驱动设计中采用DSP发生PWM脉冲波控制电机的速度与位置;同时采用了指数型加减速曲线实现快门的快速启停。实验结果表明,研制的快门叶片打开或关闭时间达到0.2s,稳定性高,整体结构设计巧妙、紧凑,完全可以满足大口径望远镜的使用要求。

To satisfy the requirement of large telescope, a large aperture focal plane shutter with aperture size ofФ200 mm was researched and designed, which could be started and stopped in a relative short time with precise position. Moreover, the blades could open and close at the same time at any orientation. Timing-belts and stepper motors were adopted as the drive mechanism. Velocity and position of the stepper motors were controlled by the pulse generated by Digital Signal Processor （DSP）. Exponential curve is applied to control the velocity of the stepper motors to make the shutter start and stop in a short time. The closing/open time of shutter is 0.2 s, which meets the performance requirements of large telescope properly.