Yong-ting DENG, Hong-wen LI, Jing LIU, et al. Low-speed control of large telescope based on disturbance torque observer[J]. Optics and precision engineering, 2017, 25(10): 2636-2644.
DOI:
Yong-ting DENG, Hong-wen LI, Jing LIU, et al. Low-speed control of large telescope based on disturbance torque observer[J]. Optics and precision engineering, 2017, 25(10): 2636-2644. DOI: 10.3788/OPE.20172510.2636.
Low-speed control of large telescope based on disturbance torque observer
To improve the anti-disturbance performance and following tracking accuracy for the servo system in a large telescope
a torque compensation method based on a disturbance observer was proposed. With the method
the revised acceleration/deceleration control method was adopt to guide the telescope turntable oscillating in a little angle. Through measuring the velocity and current of a motor
the rotation inertia of the telescope turntable was indentified. Then
an acceleration estimator was designed to estimate the low-acceleration based on encoder feedback data by using the double integration and PD control method. Finally
based on the inertia identification and acceleration estimation
a disturbance observer was designed to estimate the external torque according to the motor current and turntable acceleration. Furthermore
the estimated disturbance torque was used to compensate the current input to correct reference currents. Experiment results demonstrate that after the observer is added
the following error RMS is reduced from 0.012 7" to 0.0073" at the sloop position of servo system to be 0.36 (")/s. Compared with that without the disturbance torque observer
the following tracking jitter is reduced and the tracking accuracy is improved.
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