Design Of Indication Verification Device For External Diameter Micrometer

The indication verification of external diameter micrometer is at the stage of laboratory manual verification.The efficiency is low,the result is easily influenced by human factors.To solve these problems,to improve the efficiency and reduce the artificial error,an indication verification device for micrometer is designed.The device includes mechanical system,control system,lighting system and image processing system.The free degree of micrometer is restricted by the mechanical system to complete the fixing.The position is determined by using the line image as reference.The step motor is used as the driving source,the high precision grating ruler is selected as the detector to form the closed-loop control.The measured value of the grating ruler is regarded as the standard value.All the lighting sources on the market are compared,and the LED is selected.The scheme of ring and dome lighting are analyzed theoretically,the simulation experiments are done by Tracepro.The illumination uniformity of the surface under the circular light source and the dome light source are 72.2% and 74.6% respectively,and the actual effect is verified.From an economic point of view,the circular light source is chosen.The binary image is obtained by image preprocessing.Based on black and white mutation,the numerical recognition of fixed sleeve is realized.The numbers on the differential sleeve are identified by the threading method.The scale value of the differential cylinder is estimated by the pixel method.According to the scale values identified,the error value is calculated.The verification work is completed,and the accuracy rate of the calibration result is 90.9%.The whole indication verification work can be completed by the device.Manpower is saved.The human error is reduced.The automation of device is improved.And the credibility of the verification result is also improved.