Research on the Modulation Method Application in the Angular Sensor System

Angle measurement is an important component of the geometrical dimensional measurement technologies. It plays an important role in the modern quality control system. With the development of the precision machining and ultra-high-speed machining, the study on the method of small-angle measurement with high-precision and high-resolution in this field has become an important element. Small-angle measurement accuracy and precision have reached a high level, but there are some defects such as huge size, high cost, strict requirements on measuring environment and difficult to assemble multi-dimensional angle-measuring system in the traditional small-angle measuring instruments, for example Laser Interferometer, photoelectric autocollimator and so on. So they are very difficult to be applied in industrial high-precision on-line measurements.To solve the problems metioned above, Laser signal modulation method is adopted for the two-dimensional angular sensor to improve its performance of anti-interference capability. The system is designed and trail made. This work is prepared for the next step of designing and establishing a miniaturization multi-dimension angular and displacement measurement system to make a foundation of realizing the measurement of the moving status or errors of precision machining tool or coordinate measurement machine. The MCU MSP430 was used to improve the system speed.The main works of this paper include the followings:1, The purpose of the study is presented. A large number of references are collected and referred to, an overview of the current national and international situation and developmental trends in the field of micro angle measurement methods is discussed.2, The new angle measurement method based on light modulation angular sensor discussed theoretically.3, A modulated laser diode device, including modulated signal generation circuit and modulation drive circuit is designed and trail-made.4, The paper designed and manufactured the circuits as following: photoelectric switching circuit, amplifying circuit, regulating circuit, filter circuit, analog to digital converting circuit based on singlechip, data processing circuit and LED display circuit. MCU MSP430 was used in this system to improve the data acquisition and process speed. Each circuit was described in detail and tested.5, The evaluation method of the critical angle sensor is presented. The error factors that affect the measuring accuracy of the measurement system are discussed.