Controller

Abstract

It is disclosed that it is used to detect the maintenance needs and abnormal operation of the machine due to the long-term change resulting in the reduction of power. The acceleration detection device is attached to the driven element driven by the servo motor. The processor of each axis control circuit for feedback control of servo motor position and speed performs position and speed feedback control processing for each position / speed control cycle, thereby acquiring current commands and outputting the commands to current loop processing. The detected acceleration value αf is read from the acceleration detection means. When the detected acceleration value is not less than the threshold αs, an abnormal signal is output to display a warning and stop the machine from working. Since the acceleration of the driven element is directly detected by the acceleration detection device, it is possible to safely detect machine abnormalities such as common vibrations due to machine aging, collision of the driven element with other objects, or breakage of the element.

Description

technical field [0001] The present invention relates to controllers for controlling the position and / or speed of driven parts in machine installations, such as machine tools. Background technique [0002] In a machine arrangement, such as a machine tool, a tool is moved relative to a workpiece to be machined during machining. In order to control the position and speed of processing, the driven elements (workpiece, table, and tools, etc.) are driven by servo motors, and their position and speed are usually controlled by position, speed and current feedback. [0003] With driven elements driven by motors for position and speed control, the machine becomes progressively more prone to wobble with continued use. According to a single difference, the machine is reduced in strength, so that the operating precision of position and speed is reduced. In the case of machine tools, machining accuracy is lowered. However, it is difficult to detect these long-term changes. [0004] Co...

AI Technical Summary

Problems solved by technology

[0006] It is difficult to detect machine shaking or a decrease in machine strength caused by long-term use of the machine

[0007] Due to the limitation of the position at which the condition of the machine is observed, the information detected by the position, speed, and current detectors may fail to detect a malfunction or abnormality of the machine, or may be erroneously detected under the influence of a load estimation error

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