Absolute capacitive grating displacement rotary encoder

Abstract

The invention relates to an absolute capacitive grating displacement rotary encoder. A capacitive grating displacement sensor is adopted. An excitation voltage is applied to an emitting pole stator. Acapacitive grating current signal is coupled to a receiving pole stator through a rotating rotor. Two channels of sine and cosine signals of a roughing machine and a finishing machine are formed through a current amplifier, synchronous detection and low-frequency filtering. Through A / D conversion and signal processing by a microprocessor, a circumferential absolute value digital angle signal modulo 360 degrees is output. According to the absolute capacitive grating displacement rotary encoder of the invention, data combination is carried out on the digital angle of the roughing machine and the digital angle of the finishing machine, and through the data combination and error correction of the roughing machine and the finishing machine, a high-resolution and high-precision digital angle can be obtained, and a high-precision and high-resolution circumferential absolute value digital angle signal modulo 360 degrees can be output.

Description

technical field [0001] The invention belongs to the technical field of electromechanical integration, in particular to an absolute capacitive displacement rotary encoder, and relates to capacitive transformation technology, data frequency synthesis technology and capacitive coding technology. Background technique [0002] In the field of automatic control, rotary encoders are used to measure angle, position and speed sensors, and are widely used in the control fields of CNC machine tools, wind power generation, servo control, electric vehicles and robots. The rate occupies the main market of rotary encoders, but the structure is complicated, the volume is large, the price is expensive, and the ability to resist harsh environments is poor. Different from photoelectric encoders, magnetoelectric encoders and electromechanical encoders have strong environmental adaptability, but the accuracy of magnetoelectric encoders is low, while electromechanical encoders are complex in tech...

AI Technical Summary

Problems solved by technology

The sensor of the capacitive encoder works in a low voltage and low current state, and is easily affected by external electric fields, magnetic fields, especially power fluctuations or pulse fluctuations, causing distortion of the input signal, and even paralyzing the entire system.

In addition, the capacitive grid encoder is a quasi-absolute encoder. When the power is cut off for a long time, the battery needs to be replaced regularly, so it is difficult to use for long-term automatic measurement.

These defects are the main factors restricting the development of capacitive encoders

Images