Flight simulator table servo control based on ADRC strategy

For servo control of flight simulator table by electric-motor-drive, it would be hard to achieve high precise track by conventional algorithms or compensating means through accurate modeling due to several nonlinear or random factors, which are periodic ripple torque of motor, load fluctuation, errors of feedback sensors, friction, etc., hence ADRC (Active-Disturbance-Rejection-Controller) is adopted to estimate and compensate above-mentioned factors on-line aiming at a better servo precision for the plant. Firstly, ESO (Extended State Observer) of ADRC was designed by analyzing characteristics of flight simulator table inner-axis, thus the comprehensive disturbance instead of above-mentioned factors was observed and compensated simultaneously by ESO; secondly, Simulation study was done by establishing system model with extreme disturbance condition, and the parameters for ADRC were tuned through comparison of different simulation results; lastly, real experiment with well tuned controller was carried out to verify the validity of the algorithm on flight simulator table inner-axis. Experimental results from tracking a sine wave with amplitude of 2° show that the tracking error is great at the very moment of motor jump-starting and then is less than 0.0017° for the rest of the time, thus a high dynamic tracking performance is achieved. Furthermore, simulation and experiment reveal that robustness of ADRC is strong and to tune its parameters on nominal model is feasible for actual control plant.