Digital dual-frequency expansion state observer and disturbance observation method

Abstract

The invention discloses a digital dual-frequency expansion state observer and a disturbance observation method, and relates to the field of automatic control. Its storage structure is used to calculate the estimated error at the current moment according to the state estimated value and state measurement value at the current moment, and calculate the direction signal of the estimated error; the bandwidth switching structure is used to determine the preset high and low bandwidth switching according to the estimated error direction signal. The coefficient of the factor; the differential equation iterative accumulator is used to multiply the high and low bandwidth switching factor by the coefficient to update the actual bandwidth, and output the state estimate value and disturbance estimate value at the current moment. The invention is suitable for the automatic control of the system, alleviates the contradiction between the transient performance and the steady-state noise suppression capability of the ordinary expansion state observer, is easy to realize engineering and parameter adjustment, and the calculation amount and the required prior knowledge are different from those of the ordinary expansion state. The observers are completely consistent, and there is no artificially introduced delay, occupying less computing resources and requiring less hardware.

Description

technical field [0001] The invention relates to the field of automatic control, in particular to a digital dual-frequency expansion state observer and a disturbance observation method. Background technique [0002] In the automatic control system, the uncertainty of the controlled equipment or object and the external disturbances directly affect the control accuracy of the automatic control system. Using an observer or an estimator to estimate the disturbance in real time can effectively improve the performance of the control system. [0003] The main problem faced by the existing extended state observers is that their observation performance will be greatly affected in the presence of measurement noise. At present, most of the commonly used extended state observers are linear extended state observers designed based on the bandwidth method. Since the estimated transient and steady-state performance is proportional to the bandwidth, its actual implementation is generally a hi...

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Problems solved by technology

[0003] The main problem faced by existing extended state observers is: in the case of measurement noise, its observation performance will be greatly affected

However, the output of the belt observation system is generally polluted by noise, and the high-gain link will greatly amplify the noise pollution in the measurement signal. Simply increasing the bandwidth of the observer cannot achieve a good balance between transient rapidity and steady-state noise suppression. compromise

[0004] However, the existing extended observer design method to deal with measurement noise is mainly to adjust the bandwidth based on prior knowledge. However, for complex public or unknown fast-changing systems, it is difficult to obtain prior knowledge. If this problem cannot be solved, the extended observer The performance of the controller will be greatly affected, especially when the estimated signal is used to design the control law to control the fast time-varying system, the observation error will seriously affect the control effect of the closed-loop system

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