Control methods for time-varying sliding mode variable structure and for cross-coupling control magnetic suspension system

Abstract

The invention discloses a device based on a time-varying sliding mode variable structure control and a cross-coupling two electromagnetic suspension systems synchronous control. The device comprises a time-varying sliding mode variable structure controller which outputs a controlled quantity of a suspension system according to a suspension height error amount so as to suspend a mobile crossbeam quickly and accurately to a given height, a cross-coupling synchronous controller which adjusts synchronization performance of two electromagnetic suspension systems, a driver which drives the two electromagnetic suspension systems based on output signals of the time-varying sliding mode variable structure controller and the cross-coupling controller, and a signal detector which collects a speed and a position signal of the electromagnetic suspension systems. The synchronous control method based on the time-varying sliding mode variable structure and the cross-coupling two electromagnetic suspension systems includes that a single electromagnetic suspension system uses a time-varying sliding mode variable structure control method. The control method of the invention, while keeping such characteristics of the sliding mode variable structure as the strong robustness to the parameter perturbation and the external uncertain interference, improves the response speed of the system.

Description

technical field [0001] The invention belongs to the technical field of numerical control processing, and in particular relates to a control scheme for a double electromagnetic levitation system jointly supporting the gantry frame of a suspended gantry mobile machining center; Cross-coupled synchronization control method. Background technique [0002] Gantry mobile CNC machine tools have gradually become one of the key equipment in modern manufacturing industry due to their high machining accuracy. Its running precision and reliability play a vital role in industrial production. However, the gantry mobile CNC machine tool is a large and complex system, and its running precision is finally reflected in the design of the actuator controller. Especially the moving beam feed system, which is one of the key core parts of the CNC machine tool, controls the cutting and feeding motion of each coordinate axis, and its running accuracy determines the processing quality of the parts. ...

AI Technical Summary

Problems solved by technology

However, in the existing sliding mode variable structure control, the sliding mode surface is fixed and linear, so that the system cannot be directly on the sliding mode surface at any initial state variable.

The motion of the sliding mode is asymptotically stable, and its convergence speed is determined by the parameters set in the sliding mode surface, which cannot be adjusted, and the adaptability is poor and the response speed is slow

At the same time, because the gantry machining center uses a double electromagnetic suspension system to jointly control a suspension beam, if the two electromagnetic suspension systems are out of sync, it will affect the suspension height of the moving beam and reduce the precision of workpiece processing

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