For the optical tracking servo system with characteristics of large inertia and the non-linear friction, the improved ADRC (active disturbance rejection controller) method is designed to improve the velocity response of the servo system. This paper establishes a mathematical model of servo system and introduces the ADRC's working principle, then based on the step of the ADRC method, the parameters are given by simulation analysis, finally, the compared experiments are finished on the actual optical tracking servo system between the traditional PID controller and ADRC method. The actual results show that the ADRC method can not only achieve high speed fast step response without overshoot, and improve low-speed stability, its performance is better than traditional PID controller. Besides, the ADRC method can also improve the optical servo system speed performance by inhibiting the saturation and other nonlinear factors.

Design of active disturbance rejection controller for the velocity loop of optical tracking servo system

For the status that the framework structure of LOS(light of sight) stabilization platform for tracking are complex, based on the analysis between the framework and the LOS axis, the two-axis-two-framework structure, the three-axis-three-framework structure, and the two-axis-four-framework structure are compared, both the advantages and disadvantages are discussed, then, it is concluded that in order to isolate the disturbance of the carrier's moving stability, only the two-axis-four-framework structure is the best approach. At last, the mathematical model of the framework structure is created and the problem that the stability and accuracy of the platform framework is analysis, when in a large pitch angle moving, and then the model can be applied to the controller designing is satisfied to the actual platform.

Analysis and modeling for the framework structures of light-of-sight stabilization tracking platform

When a high precision LOS stabilized platform runs in a low speed, the precision and performance are always affected by slip-stick Its reason is the non-linear friction For dealing with the problem, the paper proposes an new integral sliding mode variable structure controller approach, and designs a novel reaching rule Actual test results of the system show that the presented controller can solve the problem of stability when the system moving a large range rapidly, eliminate the phenomenon of ”creeping”, and improve the dynamic and static quality effectively

Novel Integral Sliding Mode Variable Structure Control of High Precision LOS Stabilized Platform with Nonlinear Interference

It is necessary for high precision servo systems to use phase lag compensation with large attenuation to make the system stably conditioned Because there are saturation elements in real systems, they may cause the stably conditioned system become unstable for large offset errors A nonlinear compensator with proper use of the saturation of the operational amplifier is introduced to solve this stability problem The design principle is discussed, and the stability of the system with multiple nonlinearities is proved by using the combination of the phase plane and the describing function method

Wang Yi

Papers

A nonlinear compensator of high precision servo system