Self-disturbance rejection controller designing method capable of overcoming gap nonlinearity

Abstract

The invention discloses a self-disturbance rejection controller designing method capable of overcoming a gap nonlinearity. The method comprises the following steps: determining an order of which the valence needs to be reduced according to the number of pure integrators in series in an open-loop transfer function of a system control loop; and designing a corresponding order-reducing expansion state observer of which the reduced order equals the number of the pure integrators in series to cancel the effect of the backlash nonlinear element. According to the self-disturbance rejection controllerdesigning method capable of overcoming the gap nonlinearity, the control performance is greatly improved, so that the output of the system can perfectly track an expected input; no steady state errorexists, and finally, the adverse effect of an extreme ring oscillation is eliminated; the method needs no precise system model and gap model, and is not sensitive to the amplitude of the backlash nonlinearity; and with the exception of the backlash, the method can effectively compensate other nonlinear effects with similar characteristics such as a hysteresis nonlinearity characteristic caused byfrictions to eliminate a limiting ring oscillation associated therewith.

Description

technical field [0001] The invention belongs to the technical field of high-precision servo control, and relates to a design method of an active disturbance rejection controller for overcoming gap nonlinearity. Background technique [0002] In an automatic control system, gaps or gap-like nonlinearities inevitably exist in the system. Taking the servo system as an example, the connection between the actuator and the controlled object is mostly through transmission links such as gears, toothed belts or worms. In this kind of system, the transmission gap inevitably becomes the most important nonlinear factor, and due to its non-differentiable and non-smooth characteristics, the transmission gap cannot be linearized and the compensation is difficult. The processing methods for the gap can be roughly divided into two types: Two categories, the first category is through precision mechanical structure design and post-lubrication method, but the cost is high. If the transmission ...

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Problems solved by technology

[0008] The invention provides a design method of an ADRC controller that overcomes the nonlinear influence of the gap, and uses the construction of a reduced-order ADRC controller to suppress the influence of a nonlinear link similar to the transmission gap, and solve the limit cycle oscillation caused by the nonlinearity of the gap question

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