Research on Design of Alignment System Based on Interference Fringe
|Course||Measuring Technology and Instruments|
|Keywords||Collimator technology Interference fringes Feedback control Portability|
In recent years , a collimated laser beam measurement method as a straight-line basis over the fast development of laser collimator technology has been widely applied in the form of straightness , concentricity , flatness , parallelism bit error measurement . Difficult to overcome the problems due to the presence of the laser beam drift , the bending of light , atmospheric disturbances , the large size of the collimated laser technology detects long rail measurement accuracy has been difficult to improve . For laser collimation in the long Straightness error measurement characteristics of the design of this project based on the fringes of the portable laser collimator system . Small inclination value of the guide to the rail surface to be measured , the system will be collimated beam expander after the laser beam is projected on to the wedge-shaped optical plate , silicon photocell receiving the light beam before and after the wedge - shaped optical plate is formed after the surface reflection of the interference fringes , and then by subsequent processing circuitry , Finally , by a computer for processing measured values ??for each point of the guide surface , the calculated linear error of the measured rail . The system design of the feedback control circuit, a method of software filtering is calculated in real time the size of the DC offset in the two - way optical signal , and performs feedback control of the DC bias adjustment circuit with a proportional (P) control algorithm , to eliminate with the measurement of the optical signal includes the distance change , slow changes in the residual DC level, in order to improve the measurement accuracy of the system . The system design of the wireless communication circuit and the USB communication circuit , the measured data is sent by way of wireless communication to the wireless communication base station , and then from the base station of the wireless communication data transmitted to a computer via a USB interface ; the preparation of the application and use of VC 6.0 , to complete from USB interface to read the data , and save measurement data and calculation of rail straightness errors , making data transmission and processing of simplification . System component miniaturization , low-power design measurement subsystem , and lithium batteries to the power measurement subsystem , system portability and measurement facilitation . System stability , repeatability , calibration and long rail measurement experiments , the results show that the system can work properly , performance indicators have reached the intended target .