Research Of Virtual Absolute Rotary Encoder Using M-code

The optical electric axial angle encoder is a kind of widely used optical electric sensor for angle detecting.With the developing of sensor technology,new coded disc with single cycle coder has been used in rotary encoders.The M-coder(Maximum length sequence) is one of the excellent coding methods whose characteristic of maximum length and traversing serves the application of rotary encoder better.Virtual absolute rotary encoder is a new kind of optical electric sensor which is a new method for angle detecting.In this technology,we use single detecting photoelectric cell(SDP) to get the effective data of coder disc's position in many times'measurement.It can cut down the number of hardware a lot. This type of method is different from absolute rotary encoder and increment type.Comparing with the type of absolute rotary encoder,it reduces the complexity of light-emit and light-receive system,although the advantage of obtaining absolute position in real time is abandoned when the power is on.Comparing with the increment type,there is no accumulative total error and after a certain angle,we get the absolute coder disc position.As a type of transition to the absolute rotary encoder,virtual absolute rotary encoder adapt to the character of M-coder well and resolve the problem of no space for arranging component which should be faced by many types of single cycle coder.Two light-receive components which are apart make sure that once the encoder turns around ,the data is continuous.The virtual absolute encoder's turnaround is judged by two channels.The phase offset between them is 90°.According to the principle of M-coder,first of all,we briefly introduce the measure principle of rotary encoder.After that, we particularly describe the point of the M-coder,the generation mechanism and the method for obtaining M-coder.At last,we give out the design precept of virtual absolute rotary encoder using M-coder.This precept integrate the idea of virtual absolute rotary encoder and the character of M-coder. Although The real-precept for rotary encoder's precision of guinea pig is poor,but we make the M-coder's application in rotary encoder coming true.It will be an important reference frame for further developing of rotary encoder.