为了解决光电传感器用电动镜头盖的控制精度、抗风能力以及提高可靠性,提出了基于单圈电位器和电机驱动电流变化的级联位置检测技术。启动开盖或关盖程序后,先检测单圈电位器中间抽头电压,当抽头电压超过某位置阈值后,再检测驱动镜头盖电机的电流变化,当驱动电机的电流变化超过某一阈值时则认为镜头盖到达理想的打开或关闭状态。级联位置检测技术能够精确地检测镜头盖的终了位置,将镜头盖的控制精度控制在2°以内。此外,该技术摒弃了用于检测镜头盖终了位置的小型限位开关,提升了镜头盖的可靠性。

In order to solve the controlling accuracy problem and improve wind-resistant behavior and reliability of the motor-driven lens cover for EO sensor, a kind of cascading position measurement technology based on single circle potentiometer and suddenm motor current change is developed. When start opening or closing lens cover procedure, the voltage of middle tap of a single circle potentiometer is measured and compared with the voltage threshold value at first. When the voltage is over threshold value, the motor driven current is sampled, and the current change between two adjacent sampled driven current is calculated and compared with the current change threshold value. When the sudden current change reaches the current change threshold, the lens cover will be thought reaching the expectant final position. Then the control decision is made based on the final position of the lens cover. Lens cover final position can be measured accurately by using cascading position measurement technology, so the lens cover final position difference will be limited to 2 degrees. Otherwise the small limit switch is not used, so the lens cover reliability is improved.