Device and method for controlling gantry numerical control milling machine through double line permanent magnet synchronous motors

Abstract

The invention provides a device and method for controlling a gantry numerical control milling machine through double line permanent magnet synchronous motors and belongs to the technical field of numerical control. The method comprises the steps that firstly, a position signal is input and at this time, the two line permanent magnet synchronous motors receive the same order signal and start to operate; the actually-measured position, the actually-measured speed and the actually-measured current of a rotor of each line permanent magnet synchronous motor is determined; mixed error is calculated, the complementation sliding mode variable structure algorithm is adopted, the control rate is obtained finally, namely the control currents of the two line permanent magnet synchronous motors are obtained, and the whole calculation process is achieved in a DSP. Two sets of six-path PWM signals are generated by the DSP and drive the two line permanent magnet synchronous motors to operate respectively. According to the method for controlling the gantry numerical control milling machine through the double line permanent magnet synchronous motors, tracking errors of two axes are converted into the mixed error of a double-line-motor servo system through cross coupling control, so that the locating accuracy is improved, compared with a system controlled through a traditional method, the double-line-motor servo system is high in response speed, it is guaranteed that the tracking errors and synchronous errors are converged on zero simultaneously and rapidly, and complementation sliding mode variable structure control still has the characteristic of high robustness of tradition sliding mode control.

Description

technical field [0001] The invention belongs to the technical field of numerical control, and in particular relates to a device and method for controlling a gantry numerical control milling machine with a double linear permanent magnet synchronous motor. Background technique [0002] The dual linear motor stage has high-precision control performance and is widely used in automated production processes such as microelectronics, precision metrology, circuit assembly, printed circuit board manufacturing, and platform sheet manufacturing and inspection. The gantry milling machine is one of the most widely used dual linear motor platforms. The gantry milling machine can use multiple milling cutters to process the surface of the workpiece at the same time. It is suitable for processing large workpieces in mass production, especially for large electric equipment, marine diesel engines, and steel rolling machines. , large wind turbines and other precision machining, the CNC gantry m...

AI Technical Summary

Problems solved by technology

However, the synchronous control of the double linear motors is very difficult, because the beam spanning between the two columns and the tool holder matched with it will deviate from the center of the beam when moving and processing, for the columns on both sides , these large moving parts do not always constitute a symmetrical structure or symmetrical force; coupled with the inconsistency in manufacturing and installation, and the disturbance of various uncertain factors that are unpredictable in the processing operation, so, although the two sides of the gantry Each column adopts a set of exactly the same transmission mechanism and drive system, but in the end, the high consistency of motion cannot be guaranteed, that is, the so-called asynchronous phenomenon occurs.

In this way, the moving parts may be skewed, which further damages the accuracy of synchronous movement. The lighter ones affect the processing quality of the workpiece, and even lead to the scrapping of large and expensive precision workpieces.

In this way, it is quite difficult to achieve high-precision synchronous feed due to the existence of many uncertainties such as strong motor coupling in the dual linear motors of the positioning platform of the gantry CNC milling machine, as well as the nonlinear factors and parameter changes between the controlled object and the linear motors.

In the past few decades, the application of traditional control methods to solve the problem of synchronous feed control has achieved certain results, but it is still difficult to meet the high-precision processing requirements when used in products to achieve the highest precision. In order to meet the increasingly stringent high-precision processing requirements, Newer methods of control must be proposed

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