讨论了旋翼直升机高频振动时产生的质量不平衡力矩对航空光电稳定平台性能的影响。基于传统光电稳定平台电流反馈、速度反馈、位置反馈的三闭环控制系统提出了一种基于系统模型的质量不平衡力矩前馈补偿方法。该方法通过标定平台质量偏心, 利用加速度传感器获取平台加速度信号来对平台的质量不平衡力矩进行前馈补偿, 实现对平台质量不平衡力矩的抑制, 提高光电稳定平台的扰动抑制能力。实验结果表明: 相对于传统三闭环控制系统, 引入前馈补偿后系统的扰动隔离度至少提高了6.4 dB; 相对于利用扰动观测器对质量不平衡力矩进行补偿的传统补偿方案, 引入前馈补偿的光电稳定平台系统不仅在低频段补偿效果提升约12.9 dB, 而且克服了扰动观测器在高频时不能补偿质量不平衡力矩带来的影响, 使平台在全频段的扰动隔离度都大幅提高, 视轴能更好地稳定在惯性空间内, 具有较高的实用性和使用价值。

The effect of mass unbalanced moment under high-frequency vibration of a helicopter on the performance of a photoelectrical stabilized platform was discussed. A system model based feedforward compensation method for mass unbalanced moment was proposed on the basis of a three closed-loop control system with current feedback, velocity feedback and position feedback on the traditional photoelectrical stabilized platform. By calibrating the mass eccentricity of the platform, the acceleration signals of the platform were obtained by a acceleration sensor to perform the feedforward compensation to suppress the mass unbalanced moment of the platform. The experiment results show that the disturbance isolation increases at least 6.4 dB after inducing the feedforward compensation system as compared with that of the traditional three closed-loop control system. Moreover, as compared with that of compensation scheme using a disturbance observer, the proposed photoelectrical stabilized platform system with the feedforward compensation not only increases its compensation ability about 12.9 dB at low-frequency, but also overcomes the problems that disturbance observer can not compensate mass unbalanced moment at high-frequency. It increases greatly the disturbance isolation at full frequencies, allows the visual axis to better keep in an inertial space and shows high practical values.