Composite control method for improving anti-interference capability of brushless direct current motor

The invention discloses a composite control method for improving an anti-interference capability of a brushless direct current motor. The method comprises the steps: S1, building a brushless direct current motor state equation, concluding parameter perturbation and external load interference as total disturbance, and building a brushless direct current motor servo system state space model; S2, taking the total disturbance as an extended state variable, and reconstructing a system equivalent state space model by separating a measurable state and an unmeasurable state of the system; S3, constructing a reduced-order extended state observer, and estimating the total disturbance and the unmeasurable state of the system online; and S4, designing a backstepping controller based on disturbance dynamic compensation by using the estimated value of the reduced-order extended state observer and the measurable state of the system, suppressing the influence of disturbance on the output of the system, improving the dynamic