数字光电跟踪系统定位时的自激振荡及其抑制

Positioning Self-oscillation and Its Restraint in a Digital Optoelectronic Tracking System

由于某些非线性的影响,数字光电跟踪系统定位精度大大降低,因此相应的非线性补偿方法研究势在必行。本文以数字化光电跟踪系统为研究对象,首先进行了电视跟踪定位时影响定位精度的等效间隙非线性分析,给出了两种主要非线性的理论表达式,即量化非线性和光电探测器滞后非线性,然后采用描述函数法对实测定位自激振荡进行了定量分析,最后确定了双极工作模式的PWM功率驱动器。在实际的数字化光电跟踪系统定位实验研究中,定位误差的最大峰-峰值小于22.23″,表明双极PWM驱动器的零位振颤特性,对数字控制系统的自激振荡起到了很好的抑制作用。

For a specified digital optoelectronic tracking system, we analyze a kind of equalized clearance nonlinearity generated by the quantification and optoeleetronic sensor delay when the system is in TV tracking mode. Two main theoretical expressions of nonlinearity are shown. Then, the measured self-oscillation is characterized with the description function. The double mode PWM driver is used in the digital optoelectronic tracking system. In positioning experiments, the maximum peak-peak value of positioning error is less than 22.23″. The results show that zero-jitter feature of the double mode PWM driver can greatly restrain the self-oscillation nonlinearity.