高精度光学平台调焦控制系统

High-precision optical platform focusing control system

针对经纬仪、量子通信望远镜等光电跟踪控制系统光学平台调焦的需要,在保证跟踪控制性能和可靠性的基础上,设计了一种低成本、小体积的高精度光学调焦控制系统,以先进精简指令集计算机处理器和现场可编程门阵列为核心组成比例-积分-微分光学控制平台来实现调焦控制。分析如何提升光学平台调焦精度,利用基于缓冲运放进行信号扩展的方法提升光学平台调焦控制反馈偏差信号精度,提出3种反馈信号补偿方法并进行对比和分析,选择等分中值补偿方法对电位器反馈信号进行补偿,在不影响调焦时间的基础上简化了软硬件设计,提升了调焦精度和效率,具有低功耗、实现简单、成本低、体积小等优点。在实验中,对获取的调焦图像采用主观分析和客观评价标准相结合的方法进行调焦效果验证,证明了该设计的优势。该设计已用于某光电跟踪探测项目,在1μm级调焦精度时全程调焦时间约为3s,反应快速,性能稳定可靠。

For the focusing demand of optical platform applied in photoelectric tracking control system,such as theodolite and quantum communication telescope,a low-cost,small-sized and high-precision optical focusing control system on the basis of the guarantee performance and reliability was designed.With ARM and FPGA as the processing cores,PID optical control platform realized focusing control,according to the image-forming principle.We analyzed how to improve focusing accuracy of the optical platform and utilized the buffer operational amplifier extending the signal method to improve focusing control feedback deviation signal precision.Three kinds of feedback signal compensation methods were put forward and their comparison and analysis were done as well.An equal median compensation method was chosen to compensate the potentiometer feedback signal.This method simplified the hardware and software design without affecting the focusing time,improved the focusing accuracy and was with features of low-power consumption,easy implementation,high focusing control precision,low cost and small size.The subjective analysis was done to an image collected from the focusing experiment.The objective criterion was used to confirm the analysis.And the validity of the design was verified.This design was applied to a photoelectric tracking and detecting product,whose full focusing time was about 3seconds at 1μm-leveled precision.The design was with fast response as well as stable and reliable performance.