Research, The Psd-based Ranging System

At present, measurement technology is moving to high precision, high efficiency and automation. The non-contact distance finding is one of the important researching tasks of testing and measurement technology.Based on the survey of the non-contact measuring method, the present research status of Position Sensitive Detector (PSD) and it's development trend, present dissertation developed a distance measuring system on the base of the comprehensive knowledge of optical triangle method and PSD's operating principle; the measuring principle and the signal processing electrocircuit of the PSD's output signal are throughly studied;at last the reasons for causing error about the present system are analysed with experiment in details.The present dissertation is organized as follows:1. The distance measuring principle based on PSD is studied throughly. The relationship of position dimension and optical system is analyed, the relationship of angle for PSD and optical axis, and especial instances are discussed. PSD's Operating principle, characteristicon of signal output are analysed.2. The compose of distance measuring system is designed. System's hardware is analysed and chosed. Introduce the basic signal processing circuit of PSD detailedly. Circuit's preamplifier is studied throughly, Improve the basic signal processing circuit of PSD. Adopting sample-hold method to avoid dark-current and background light; utilizing software to replace analogue divider in order to improve stability.3. System software is programed, then user interface module, demarcate module, auto-measureing module, data logging and data-processing module are mainly introduced.4. Experiment with distance measuring system. Experiment includes system scaling, system stability, system precision and affect of different background light on system performance. Testing data and testing environment are summarized, system's error isanalyzed.5. Finally, main results and conclusions of this dissertation have been summarized; the prospects and studying emphases of the future research have been discussed and forecasted.