Low-speed direct-drive motor disturbance suppression method based on sliding mode and disturbance compensation

Abstract

The invention discloses a low-speed direct-drive motor disturbance suppression method based on a sliding mode and disturbance compensation. The method is applied to the technical field of direct-drive servo of aerospace, robots, numerical control machine tools and the like. Aiming at the defects that the sliding mode controller is complex in design and the time-varying disturbance suppression effect is not obvious during low-speed operation, a mode of combining the low-speed sliding mode controller and the reduced-order state observer time-varying disturbance compensation is adopted, the system structure complexity is reduced, and the disturbance suppression effect during low-speed operation of the motor is improved. According to the method, the influence of low-frequency disturbance is mainly inhibited by the sliding mode controller, disturbance information does not need to be provided, the structural design is simple, load disturbance feed-forward compensation is added, the motor can be driven to simultaneously inhibit low-frequency and medium-high-frequency torque pulsation at an extremely low rotating speed, and the control precision of the direct-drive servo motor during low-speed operation is improved.

Description

Technical field [0001] The present invention relates to the field of motor control, and particularly to a sliding mode disturbance compensation based on the low-speed direct drive motor disturbance suppression method. Background technique [0002] Direct-drive permanent magnet synchronous motor servo system in recent years, widely used in aerospace, CNC machine tools and other high-performance, high-precision control applications. Direct drive system does not use a reduction gear mechanism, a servo motor connected to the load, and there is no backlash motion transmission lag to achieve higher accuracy, efficiency and responsiveness. But the same face many problems: such as motor cogging, load changes, higher current harmonics and other disturbances mechanical friction, since no intermediate links of the reducer, acting directly on the motor shaft, affect the running accuracy of the speed control system stability and, at the same time, the influence of the disturbance torque, whil...

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Problems solved by technology

[0004] Aiming at the deficiencies of the above-mentioned prior art, the main technical problem to be solved by the present invention is that the control rate and observer design of the existing sliding mode method are complicated, and the low-frequency time-varying torque disturbance suppression effect is not obvious during low-speed operation, and a new method is proposed. A torque disturbance suppression method for low-speed direct-drive motors based on sliding mode and disturbance compensation, which has the advantages of being able to suppress the influence of low-frequency disturbances, without providing disturbance information, and having a simple structure design. Simultaneously suppress low-frequency and medium-high frequency torque ripple at extremely low speeds, improving the control accuracy of direct drive servo motors at low speeds

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