Code wheel fault self-diagnosis method for photoelectric absolute value encoder

Abstract

The invention discloses a code wheel fault self-diagnosis method for a photoelectric absolute value encoder. A code wheel fault self-diagnosis system includes a processor, an optical system, a counter, a power source, a transceiver, a protection circuit and a wiring terminal. The input terminal of the processor is connected with the power source and the transceiver. The output terminal of the processor is connected with the optical system and the counter. The output terminals of the power source and the transceiver are connected to the processor. The input terminals of the power source and the transceiver are connected with the protection circuit. The protection circuit is connected with the wiring terminal. According to the invention, aiming at a problem that errors of metal code wheels, plastic code wheels and glass code wheels may become more and more distinct and a user cannot judge whether they can still be put into use or not by other means, a function of implementing a code wheel fault self-diagnosis algorithm is added for the encoder, so that potential risks are avoided and self-diagnosis can be performed when product problem occurs. In this way, benefits of customers are guaranteed.

Description

technical field [0001] The invention relates to the field of encoders, in particular to a method for self-diagnosing code disc faults of a photoelectric absolute value encoder. Background technique [0002] Absolute is relative to the increment. As the name suggests, the output signal of the photoelectric absolute encoder is a unique digital coded value at each position within the measurement range. It is mainly composed of transmitter, code disc, optical receiver and conversion circuit. Different from the incremental photoelectric encoder, the absolute encoder has several concentric code tracks in the radial direction of its circular code disc, each of which is composed of light-transmitting and opaque sectors. A fixed digital code corresponding to the position can be obtained through the photoelectric receiving unit. Because each position is absolutely unique and does not need power-down memory, it has been more and more widely used in angle measurement, length measureme...

AI Technical Summary

Problems solved by technology

Due to the inherent stress relationship between the width and thickness of the opening, the metal code wheel cannot make the hole small enough to obtain high resolution and precision; the plastic code wheel can obtain sufficiently fine grating engraving, High resolution and precision, while the characteristics of cold and brittle at low temperature and high temperature thermoplastic limit the working temperature range of the application; Under vibration, relatively fragile

[0004] During the working process, due to temperature, vibration and other reasons, the three kinds of code discs may be damaged to varying degrees. Some of them can be used continuously, and some of them may bring profit losses to customers if they continue to be used.

[0008] 3) The thickness of the metal code disc is very thin, and its performance in terms of shock resistance and vibration resistance is weak. When the code disc is slightly deformed due to vibration, the resolution of the code disc will be affected, thereby affecting the accuracy;

[0009] 4) Plastic code discs and glass code discs, because the code-carrying grating pattern is attached to the surface of the code disc, and the technology requires that it must be close enough to the mask grating to suppress beam crosstalk, the grating pattern may be garbled. The common point of the code wheel and the glass code wheel is that the difference is that the thermal expansion and contraction of the plastic code wheel is more obvious than that of the glass code wheel, and the resolution and accuracy are generally not as good as the glass code wheel. The characteristics of plastic limit the working temperature range of the application; while the glass code wheel has a wider working temperature, the price is relatively expensive, and it is relatively fragile when exposed to shock and vibration.

[0010] In short, regardless of metal, plastic or glass code discs, in the long-term use process, it is inevitable that vibration, temperature or bearing wear will cause uncertain factors such as code disc eccentricity, which will cause the encoder error to increase, and the user It cannot be detected, which brings potential crisis to users

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