Design Of The Signal Detection System Of Internal Reflection Angle Sensor

With the rapid development of science and technology, the machining andmanufacturing enjoy a fast moving forward to the ranks of the ultra-precisionmachining industries. In the modern enterprise quality assurance system and industrialgeometry measurement test, the accuracy requirement of online detection has beengreatly improved subsequently. An online detection technique with high precision,high resolution and high reliability, especially small-angle measurement technique isparticularly important for both enterprises and industrial production. At this stage, theaccuracy and precision of the small angle measurement technique has also beengreatly improved, especially the optical angle measurement technology. The higherprecision and accuracy of the optical angle measurement is, the more complex theequipment is and the higher the requirement of signal interference is.In order to meet the high demands of the small optical angle detect system, a signalmodulation and demodulation system was designed based on the optical internalreflection light intensity detection methods, and the processing circuit was analyzedand simulated in order to improve the anti-interference ability as well as the accuracyof the measurement. The laser light was modulated directly with a sine wave to realizethe real-time detection, processing and display. Furthermore, a tiny angle measuringsystem was built by combing with the small-angle optical measurement devices, withthe purpose of laying the foundation for the next online detection steps.This dissertation includes the following aspects:1. The purpose and significance of the research was presented, and the domesticsituation and development trend of the small angle measurement technology werereviewed by collecting information.2. The principle of modulation and demodulation was analyzed and the method ofthe light intensity modulation and phase-sensitive demodulation of the laser lightsource was introduced.3. According to the principle of the sensor, a stable LD drive circuit, a modulationcircuit, a start buffer device which can protect the circuit, a phase-locked circuit and ademodulation circuit, an AD converter circuit, data processing&display device basedon MSP430were designed. 4. Data conversation program was wrote and tested by combining with the AD andMSP430devices. Analyzed the results of the data processing devices and the reasonsof error.