光电搜跟系统在低速跟踪状态工作时, 由于转轴之间存在非线性摩擦力矩, 会引起跳动或“爬行”现象, 非线性摩擦力矩还会降低角分辨率和重复精度, 对跟踪精度的影响很大。对此, 提出了一种基于遗传算法的摩擦建模与补偿方法: 首先, 选取Stribeck摩擦模型, 利用遗传算法辨识光电搜跟系统的Stribeck摩擦模型, 以获得较高的模型拟合程度, 降低拟合误差; 在此基础上, 对所辨识出的摩擦进行前馈补偿, 以减小非线性摩擦力矩对光电搜跟系统性能的影响; 仿真和实物实验证明了所提方案的有效性, 提高了光电搜跟系统的控制性能, 取得了较好的补偿效果。

When Electro-Optical Tracking System (EOTS) is working in a low-speed tracking state, the nonlinear friction torque between shafts of the EOTS may cause “flat-top” or “creeping” phenomenon, and also decrease the angular resolution and repeatability precision, which has a great influence on tracking precision. A friction modeling and compensation method based on Genetic Algorithm(GA) is proposed to solve the problem. Firstly, GA is adopted to model a Stribeck nonlinear friction of the EOTS to obtain a higher degree of model fitting and reduce the fitting error of the friction model. Then, a feedforward compensation is made to the identified friction, and thus to reduce the effect of the nonlinear friction torque on the EOTS.Results in simulation and physical experiments show that the proposed scheme is effective in friction compensation, which can improve the control performance of the EOTS.