Design And Analysis Of A Device For Indication Automatic Verification Of Vernier Caliper

With the continuous development of science and technology,industry has been proposed higher requirements on dimension accuracy of spare parts.Measuring instruments(such as vernier caliper,micrometer,dial indicator,etc.)has been widely applied to mechanical processing,the accuracy is the assurance of spare parts' quality.Vernier caliper is selected as the common measuring instruments,its verification method is still dominated by manual verification at this stage,the manual verification process is high repeatability,low efficiency and the detection results are easy affected by human factors too.In order to solve those verification problems and improve the verification accuracy,this paper presents an automatic verification device of vernier caliper which is based on machine vision.Vernier caliper automatic verification device is an intelligent verification instrument which integrates mechanical system,electromechanical control system,visual system and image processing system.It uses high-precision grating displacement sensor instead of standard gauge block as a measurement standard,the movement direction of the device is the same as the movement of vernier caliper direction to reduce Abbe error.The device uses the stepping motor to replace the manual operation to drive the ball screw and control the slider movement to drive the vernier caliper moving on.Through the design of motion control driving system and the feedback control,it realizes the control of verification system of servo closed loop movement to guarantee the high precision vernier calipers accuracy requirements in terms of the hardware respect.It uses machine vision technology instead of the human eye to capure the venire caliper indication image in real-time.After finishing the image processing,the caliper values will be acquired and compared with the grating indication to get the error.It uses the Internet information management technology to transmit verification data to the remote computer and store verification data in the measurement information management system in real-time to realize the network transmission and storage of the data.The invention of the device not only improves the precision and accuracy of the calibrating device,but also makes the whole process automatic operation,saves manpower and improves the efficiency of verification.