A reduced-order active disturbance rejection controller and its establishment method

Abstract

The invention provides a reduced-order active disturbance rejection controller and an establishing method thereof. Order reducing can be carried out by effective utilization of determined and relatively constant partial information in system dynamics; an extended state observer is designed according to a reduced-order dynamic equation; because the order is reduced, the bandwidth of the observer can be properly increased; therefore, the estimation effect of internal disturbance and external disturbance generated by structure or parameter change of a controlled object is improved; the stabilityof the system is not influenced; order reducing of the controller is carried out by utilization of a relatively constant certainty model in the system dynamics; a basically constant part in the controlled object of the system is identified and distinguished; then, on the basis of the established certainty model, order reducing is carried out; finally, the extended state observer and the active disturbance rejection controller are designed for the reduced-order system; and thus, both the tracking performance and the disturbance rejection performance are good.

Description

technical field [0001] The invention relates to the design of an Active Disturbance Rejection Controller (ADRC), which belongs to the fields of automatic control theory and engineering practice, in particular to a reduced-order ADRC controller obtained by utilizing a relatively constant definite model in system dynamics and a method for establishing the same. Background technique [0002] For the actual controlled object, the higher the order of the object, the more state variables need to be controlled, the greater the phase lag in the output signal, and the greater the difficulty of control. In the traditional design method, the controlled object is usually simplified, and then the controller is designed according to the simplified controlled object model. For high-order systems, including nonlinear systems, the usual method is to decompose the system into multiple cascaded subsystems by selecting appropriate state variables and coordinate transformations, and then design ...

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Problems solved by technology

On the surface, the ADRC order of each loop has decreased. In fact, the ESO bandwidth of each loop gradually increases from the outside to the inside, and the difficulty of implementation also increases in turn. If the ESO bandwidth of the inner loop is not enough, the control performance of the outer loop is the same. affected, causing performance degradation

In addition, in theory, the differential of the output signal can be extracted, and the order of the differential equation of the system can be reduced by variable substitution. In practice, this method is limited by the noise in the differential signal, and only the low-order differential signal can be barely applied, while the high-order differential It will greatly amplify the noise in the measurement process, so the high-order differential signal output by the system cannot be used to achieve the purpose of order reduction

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