Method of diagnosing abnormality of reduction gear and apparatus for carry out the method

Abstract

An apparatus for carry out a method of diagnosing abnormality of a reduction gear, the reduction gear including an intermediate shaft element disposed between an input shaft and an output shaft and rotating in proportion to a rotation of the input shaft to transmit the rotation to the output shaft, the apparatus has: a disturbance observer that obtains an estimated disturbance value regarding the reduction gear, based on a torque instruction and a velocity feedback-value acquired when a pair of driven members which rotate relative to each other with a motor as a driving source are in relative rotation at a constant velocity; a specific spectral component specifying portion for extracting a specific spectral component corresponding to a constant multiple of a rotational frequency of the intermediate shaft element from a frequency components of the estimated disturbance value obtained by frequency analysis; and a diagnosing portion, which compares an amplitude of the specific spectral component specified by the specific spectral component specifying portion with a threshold value, and diagnoses an abnormality in a case where the amplitude of the specific spectral component exceeds the threshold value, or a normality in a case where the amplitude of the specific spectral component is equal to or less than the threshold value.

Description

technical field [0001] The present invention relates to a reduction gear abnormality diagnosis method and a reduction gear abnormality diagnosis device for diagnosing an abnormality of a reduction gear having an intermediate shaft that transmits rotation between an input shaft and an output shaft and rotates in proportion to the rotation of the input shaft. A component such as a crankshaft for eccentrically rotating an external gear that meshes with an internal gear. Background technique [0002] As a speed reducer abnormality diagnosis method, there is a method of diagnosing a speed reducer abnormality based on information of a sensor mounted on a portion to be diagnosed. This diagnosis method is very effective in that abnormalities of robots, machine tools, etc. can be found without damage, but on the other hand, it has various disadvantages because it becomes an afterthought after the abnormality has occurred. For example, it takes a very long time to repair the reducer ...

AI Technical Summary

Problems solved by technology

[0004] In the above-mentioned conventional method, since the signal detected by the sensor includes various noises, it is impossible to directly extract only the signal that is effective for the diagnosis of the joint, and there is a concern that the occurrence of an abnormality cannot be accurately predicted from the detected signal.

In other words, in the conventional method, if the difference between the frequency component of the signal detected by the sensor and the normal frequency component is large, it can be regarded as an imminent failure. In the state where the abnormal signal and noise of the joint are mixed, it may not be possible to clearly distinguish the difference between the abnormal state and the normal state of the joint.

[0005] In addition, since the signal detected by the sensor changes due to the influence of gravity, the magnitude of the detected signal is unstable depending on the position and posture of the joint, and there is a problem that the reliability of the diagnosis result is poor.

[0006] In addition, it is necessary to install sensors for detecting abnormalities on robots or machine tools, and there is a problem of additional cost equivalent to the purchase cost of sensors

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