Multiple-loop absolute type rotary encoder based on rotating transformer

Abstract

The invention relates to a multiturn absolute rotary encoder based on a rotary transformer, which is characterized in that: a sensor is displaced by taking the rotary transformer as a shaft angle; a shaft angle decoding circuit can be formed by adopting DSP as a core processor; a sine wave which can be controlled by frequency and phase in the method that the circuit is synthesized by direct digital frequency for the numerical control of an oscillator; and the sine wave is directly taken as an excitation rotary transformer signal via a power amplifier and a filter circuit; the rotary transformer signal is transferred to A/D converter after being run through a matching circuit of electronic transformer; after sampling, digital filtering and digital signal processing, the sine and cosine value for the actual angle of two channels is generated; the angle error change is tracked dynamically by the PI algorithm; the mechanical displacement of the rotating object is converted into digital shaft angle position and speed. The multiturn absolute rotary encoder based on a rotary transformer has the advantages of high tracking speed, high conversion accuracy, high reliability, simple structure, sensitive movement, low environmental condition, strong anti-interference capability, high measuring accuracy and speed voltage output.

Description

technical field [0001] The invention relates to an encoder, in particular to a multi-turn absolute rotary encoder based on a rotary transformer, and belongs to the technical field of electromechanical integration. Background technique [0002] The basic components of CNC machine tool servo system include position control unit, speed control unit, drive element (motor), detection and feedback unit, and mechanical execution components. The position control unit largely determines the accuracy that CNC machine tools can achieve. At present, position sensors generally use components such as high-resolution resolvers, photoelectric encoders, and magnetic encoders. The resolver outputs two-phase quadrature waveforms and can output the absolute position of the rotor, but its decoding circuit is complex and expensive. Magnetic encoders, which rely on changes in magnetic poles to detect position, are currently under research and have low resolution. [0003] Photoelectric encoder i...

AI Technical Summary

Problems solved by technology

However, the photoelectric encoder also has the following disadvantages: precision but higher protection requirements for outdoor and harsh environments; measurement of linear displacement depends on the conversion of mechanical devices, and the error caused by mechanical clearance needs to be eliminated; it is difficult to detect orbital objects to overcome slippage. Poor; no speed voltage output

Therefore, this greatly limits the application range of photoelectric encoders

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