一种光强度传感信号的模拟闭环检测方法

Analog closed-loop detection method of light intensity sensor signals

介绍了一种对光强度传感信号的闭环检测方法,讨论了该方案的原理及可行性,对比了闭环方案与传统开环方案的优缺点,给出了环路稳定性条件。闭环检测方法采用乘法器和PI控制器构成闭环自动增益控制回路取代开环方案中的模拟除法器,消除了原始传感信号中的低频分量,即光源光功率波动干扰信号,提高了传感精度。闭环方案较开环方案具有很好的抗干扰能力、一致性和参数稳定性等优点。实验表明,实验结论与理论分析一致。

This article introduces a closed-loop detection method, discusses the principle and feasibility of the method, compares the advantages and disadvantages of the novel closed-loop scheme and traditional open-loop scheme, finally computes the stability conditions. Closed-loop method utilizes multiplier and PI controller as the replica of divider used in open-loop scheme to form the closed-loop auto gain control circuit. It can accurately eliminate the low frequency component arisen from the power fluctuation of laser power. After the control loop, the sensor signal has nothing to do with the laser power and the sensor precision is improved. Closed-loop scheme is superior to open-loop scheme due to its excellent anti-interference ability, consistency and stability of parameters. Experiments showed that experimental conclusion conforms to the theoretical analysis.