Inertia online identification method and system of servo motor drive system

Abstract

The invention relates to the field of servo motor control, in particular to an inertia online identification method and system of a motor servo system. Load torque state observation of a motor is obtained by a built full-dimensional observer; given electromagnetic torque of the motor is obtained; a built self-adaptive mechanism is used for determining a real-time correction parameter of an adjustable reconstruction system according to the load torque and the electromagnetic torque; zero-difference convergence of output of the adjustable reconstruction system and the output of an actual system is ensured; reconstruction of an actual object system can be finished; and a built self-adaptive identification mechanism outputs and identifies a rotational inertia and a viscous friction coefficient of a permanent magnet synchronous motor servo system according to the real-time correction coefficient of the adjustable reconstruction system under the stable condition.

Description

technical field [0001] The invention relates to the field of servo motor control, in particular to an inertia online identification method and system of a servo motor drive system. Background technique [0002] When the motor often works in multiple working conditions or the working state changes, some system parameters will change in a large range during operation. In this case, it is often difficult to achieve the expected control goal. Moment of inertia and viscous friction coefficient are the system parameters that vary with the load torque in the entire controlled system, and are the main factors affecting the selection of controller parameters, especially the viscous friction coefficient of the motor is a nonlinear function of the angular velocity of the motor. method is difficult to identify. Therefore, the observation of the disturbance load torque and the accurate identification of the equivalent moment of inertia and viscous friction coefficient are important prer...

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Problems solved by technology

[0004] For the identification of the moment of inertia, it is mainly divided into two types: offline identification and online identification. The commonly used offline identification methods include: direct calculation method, acceleration and deceleration method, etc. In order to simplify the problem, the acceleration and deceleration method only calculates the rotor inertia of the servo motor The friction torque is ignored, and the influence of the friction torque is weakened by taking the average value of its speed and acceleration and deceleration time. Since this method has no error iterative convergence process, it cannot be tracked online and the identification results fluctuate within a certain range; The identification algorithm includes traditional methods such as least squares and reference model self-adaptation. Due to the large amount of data processed by the least squares identification, DSP is required to have high data processing speed and storage capacity. Therefore, a method based on forgetting factor is also proposed. The least-squares identification method based on the method approximates that the measured electromagnetic torque is the current load torque. The disadvantage is that when the load disturbance changes in a large range during the transient process, the old load torque estimation value still participates in the recursive process. Distortion

The usual model reference adaptive identification algorithm adopts the MIT adaptive mode, which can use the adaptive law gradient descent method to simultaneously realize the identification of the moment of inertia and viscous friction coefficient. Because of the contradiction, its processing speed can only be used for offline identification, and the identification accuracy is related to the manual selection of adaptive gain, its application is severely restricted

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