Anti-interference compound control method of permanent magnet synchronous motor servo system based on backlash compensation

Abstract

The invention discloses an anti-interference compound control method of a permanent magnet synchronous motor servo system based on backlash compensation. The method is based on nonlinear system identification, a finite time interference observer and a sliding mode control technology, and comprises the following steps of: firstly, obtaining a motor system of a current PI control closed loop based on a vector control scheme of a permanent magnet synchronous motor; secondly, aiming at the approximate dead zone backlash nonlinear model, identifying key parameters of the backlash model by adopting a nonlinear least square iterative algorithm; thirdly, estimating gear transmission torque according to the identified backlash model; aiming at lumped disturbance existing in the system, designing a high-order sliding mode observer with finite time convergence to observe the lumped disturbance; and finally, designing a composite anti-interference controller based on the sliding mode technology in combination with estimation of gear transmission torque and lumped disturbance. According to the scheme, the influence of backlash nonlinearity and other system uncertainty and disturbance factors is effectively suppressed, the anti-interference capability is high, and the tracking performance and the steady-state precision of the system are ensured.

Description

technical field [0001] The invention relates to a compound anti-interference servo control method for a permanent magnet synchronous motor servo system with backlash nonlinearity and uncertainty disturbance, and belongs to the technical field of motion control and servo. Background technique [0002] In recent years, with the rapid development of advanced control theory and modern science and technology, servo systems have been widely used in production practice, and permanent magnet synchronous motors have also been rapidly promoted under the development of motor control theory and power electronics technology. However, the nonlinear link, parameter uncertainty and load disturbance in the permanent magnet synchronous motor servo system are the main factors restricting its control performance, especially in high-precision applications. With the development of microelectronics technology and integrated circuit technology, the computing power of servo system hardware equipment...

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Problems solved by technology

However, the difficulty of this scheme lies in the control of switching timing, and most of the current switching control strategies do not take into account the disturbance caused by gear collision, so they cannot be well realized in practice.

The literature (R.L.Dong, Q.Y.Tan, Y.H.Tan, A Non-smooth Nonlinear Programming Based Predictive Control for Mechanical Servo Systems with Backlash-like Hysteresis[J].Asian Journal of Control,2018,20(4):1519-1532) proposed a A multi-step-ahead predictive control method for servo dynamic systems with backlash hysteresis characteristics based on non-smooth nonlinear programming. In this method, a non-smooth multi-step-ahead prediction model is established to control Servo dynamic system for long-term prediction, but this paper only considers the hysteresis characteristics of the backlash, and the method is limited to theoretical research, and engineering application is difficult

Literature (Y.F.WANG, J.W.MA, A Dual-motor Anti-backlash Algorithm Based on Tracking System of Ship-borne Antenna [J]. Equipment Manufacturing Technology, 2018, 7:123:132.) proposed a dual-motor anti-backlash algorithm based on speed loop Motor anti-backlash technology, and theoretical analysis and experimental verification of the dual-motor anti-backlash technology, but the shortcomings of this scheme are also obvious. The multi-motor anti-backlash control method comes from engineering practice, and there are many engineering applications but insufficient theoretical research. Moreover, due to the increase of driving devices, new problems such as high cost, high system complexity, and difficulty in multi-motor coordination have been brought.

[0006] In addition to the nonlinear problem of backlash, the servo also has factors such as load disturbance, system uncertainty, and other nonlinearities.

How to better solve the problems of backlash nonlinearity, external disturbance and system uncertainty in the servo system is the main purpose of this patent

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