Abstract:

Based on the predictor tracking differentiator, a special linear active disturbance rejection controller (LADRC) is proposed for a system subject to measurement noise. Firstly, the algorithm of the predictor tracking differentiator is given and analyzed with the frequency domain method. Secondly, a special LADRC law for vehicle attitude control is designed, the noise suppression ability of the proposed method is analyzed by weariness degree, and the closed loop frequency characteristic of the controller is studied. Lastly, the controller is tested and compared to the first order filter and normal linear tracking differentiator filter by the hardware-in-the-loop (HIL) test. The HIL test shows that the predictor tracking differentiator is able to filter out the measurement noise effectively, reduce the influence of the noise amplified by the extended state observer, and at the same time make a good balance between the noise filtering and the phase compensation. The improved LADRC law combined with the predictor tracking differentiator is more robust to measurement noise than the normal LADRC and has a good potential for engineering applications.

Key words:  Linear active disturbance rejection controller, Tracking differentiator, Noise suppression