基于扰动观测器的伺服系统扰动抑制研究

Anti-Disturbance Study of Servo System Based on Disturbance Observer

扰动观测器能够实时、准确地观测负荷扰动的变化,并将干扰量等效成相应的电流形成前馈补偿,有效地降低负载扰动对伺服系统的影响。然而,较大的观测噪声使其扰动抑制功能严重受限。当系统存在观测噪声情况下如何提高扰动观测器的扰动抑制功能,提出一种新型基于Kalman滤波的扰动观测器设计方案,最大限度地减小负载扰动和观测噪声等因素给伺服系统带来的影响。实验从Kalman滤波器转速估计的准确性、负载转矩观测的实时性和采用所提出方案的伺服系统整体性能3个方面进行了详细的分析和对比验证,实验结果证明所提出方案比已有方案所产生的效果有所改善,有效地提高了系统的控制精度和扰动抑制性能。

Disturbance observer can accurately observe the change of the load disturbance, and form a feedforward compensation to effectively reduce the effect of load disturbance to the servo system. However, the larger observation noise severely restricts disturbance rejection. According to how to improve the disturbance rejection performance of disturbance observer at the presence of observation noise and proposes a new design scheme of disturbance observer based on Kalman filter, so as to maximum reduce the load torque disturbance and observation noise. Detailed analysis and comparative exper- iments were carried out from three aspects： the estimation accuracy of Kalman filter speed observer, the real-time perform- ance of load torque observation, and the overall performance of servo system with the proposed scheme. Results showed that the proposed scheme had better performance compared with existing schemes and it could effectively improve the control precision and disturbance resistance performance of servo system.