Relative type rotary encoder and measurement method thereof

Abstract

The invention discloses a relative type rotary encoder and a measurement method thereof. The rotary encoder comprises a round coding disc, a rotary shaft, a data processing module, a casing, multiple light source systems and multiple photoelectric sensors, wherein a relative code channel and a reference zero code channel are arranged on the outer side surface of the round coding disc, the relative code channel comprises multiple grating strips which have the same width and are uniformly engraved on a circumference of the outer side surface of the round coding disc, and the reference zero code channel comprises two grating strips with different widths; the light source systems are all installed on the casing and are located in the radial direction of the round coding disc respectively; the plurality of photoelectric sensors are installed on the outer side of one light source system respectively and are connected with the data processing module. The relative type rotary encoder can avoid measurement errors caused by radial vibration, is high in measurement precision, anti-interference capacity, anti-pollution capacity and reliability and can be widely used for the field of rotation angle measurement.

Description

technical field [0001] The invention relates to the field of rotary encoders, in particular to a relative rotary encoder and a measuring method thereof. Background technique [0002] The motor of an AC servo motor is usually equipped with a photoelectric rotary encoder to measure the rotation angle of the motor. The photoelectric rotary encoder can obtain the rotation angle of the rotor to obtain the motor speed information, and the speed information can be fed back to the relevant speed control unit to accurately control the motor. At the same time, the movement displacement, speed, acceleration and other information of the actuator can be calculated indirectly. The positioning accuracy of the servo motor depends on the resolution of the encoder. Photoelectric rotary encoder is a sensor that converts the mechanical geometric displacement on the output shaft into pulse or digital quantity through photoelectric conversion. It is currently the most widely used sensor in the m...

AI Technical Summary

Problems solved by technology

[0003] Incremental encoders can only provide information about the current position relative to the previous position. After the power is interrupted, the information change of the position must be reset to zero before it can be confirmed. At the moment when the power is turned on again, the incremental encoder The server cannot immediately know the current location of the organization

The grating code disc of the incremental encoder is a circular grating disc with several rectangular holes equally divided on a circular plate with a certain diameter. The grating code disc of the absolute encoder is provided with several concentric holes along the radial direction on the grating plate Track, each track is composed of light-transmitting and opaque fan-shaped areas alternately. Both of them use circular grating code discs, because the grating code discs of both are depicted on the circular plane perpendicular to the motor axis, and the motor is running In the process, a certain radial runout will inevitably be generated due to vibration, which may cause a small displacement of the code track of the grating code disc. When the radial displacement caused by vibration reaches a certain amplitude, it may cause the encoder to read incorrectly. Affect the accuracy of the measurement results

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