Abstract: In order to improve the isolation degree of disturbance of photoelectric stabilized platform, a friction compensations strategy based on Disturbance Observer (DOB) was put forward. First, the model of velocity loop was established by mechanism analysis, then a disturbance control scheme was proposed. Second, the identifications of the friction model parameters were determined by experiments. Based on the friction compensation control strategy, the DOB control strategy was designed. The accuracy of the strategy was verified by experiments. Finally, in order to test the feasibility and necessity of the control scheme, the aerial photoelectric stabilized platform was installed on the simulation platform, and the disturbance rejection capability of the platform was tested after the friction compensation and DOB were used. Experiment results show that, when the frequency of disturbance is within 3 Hz, the system disturbance isolation degree is increased by at least 14.52 dB. When the system is running at low speed, the tracking performance is improved obviously, and the tracking error is reduced from 0.1959 °/s to 0.0838 °/s. This control strategy can attenuate the mass unbalance torque. It has strong robustness and practical value.

Key words: automatic control technology, aerial photoelectrical stabilized platform, friction compensation, parameter identification, disturbance observer(DOB)