Study On The Gauge Block Automatic Calibration System Based On Point To Point

Gauge block calibration is one of the key parts of length metrology. By using gauge block, the length definition can be transferred to mechanical components and products, realizing the length traceability. With the development of technology and economy, the enterprises expect more gauge blocks can be calibrated with higher length traceability. So developing a calibrating system with high precision, automation and high efficiency has become an urgent requirement for the industrial applicationIn order to decrease the manual location operation error, a two-dimensional moving platform driving by stepper motors is used to change the measurement points on the surface of standard or measured gauge blocks. By applying'one vs. multiple', the standard block's number is decreased greatly to cut down the calibration cost. Temperature sensors are used to get the temperature of gauge blocks in real time and compensate the change of the gauge block's length. In order to avoid the errors caused by manual reading and calculating data, measurement software is designed to process data and evaluate grade automatically.The main research contents include:1. On the basis of understanding gauge block calibration rules, calibration methods and research, a gauge block calibration system based on'point to point'is designed.2. Collecting and processing module is designed based on MCU, which is used to acquire small signals, measure gauge block temperature, control the automatic positioning of the two-dimensional moving platform and communicate with the computer.3. The acceleration or deceleration algorithm for stepper motor is designed to reduce vibration disturbance during movement and to improve the positioning accuracy of the moving platform. Two kinds of circuits for small inductive signal processing are designed.4. Measurement software is developed to control the two-dimensional moving platform, the laser interferometer and the inductive sensor. It can store and process data, determine the grade of tested gauge blocks and print the certificate automatically.5. Establishing the mathematical model of the system and doing measuring uncertainty analysis to show that it meets the requirement of calibrating third grade gauge block by using standard second grade gauge block. A series of experiments are given and the results are analyzed to verify the reliability of the system.