Research & Realization On Vital Techniques Of Optical Self-collimation Angle Sensor

Optical self-collimation angle is widely applied for its advantages of non-contact, high-accuracy and high-sensitivity. CCD(Charge Coupled Devices) is a semiconductor photoelectric device. The system with CCD has an advantage on geometrical measure such as angel measure for achieving high accuracy.Firstly, the principle of optical self-collimation angle sensor and the research work of linear CCD principle are introduced, which are based on to design optical focusing and imagery system with semiconductor laser instrument as illuminant. Secondly, peripheral circuit of linear CCD is designed in theory and experiment. Finally non-contact angle measurement instrument is constructed, using CCD as photoelectric transformation element as the controller.In this paper, the time order driving circuit of CCD is described and designed with VHDL and CPLD, which make the whole driving circuit volume smaller, shorten design period, modify design at any time, and enhance reliability and agility of circuit. The CPLD designing under MAX+PLUS II can complete all work, which makes hardware design convenient as software design. The video signal processing circuit realizes the primary catching; filtering and signal amplifying. Variable threshold binarization processing circuit and two-channel counter are designed to sample to count the output pulse signal, which is processed, deposited and displayed in microprocessor. The communication interface circuit with the computer is also designed.The experiment of CCD driving and signal processing circuit shows that the drivers can assort with CCD well, take advantage of the characteristic of CCD photoelectric transition and output steady and reliable electric signal. Video processing circuit can obviously restrain the main noise, enhance SNR and obtain high quality video signal for further signal processing. Hardware design and software program of the microprocessor are completed, and system error is analyzed. Principle analysis and experiment result indicate that the optical self-collimation angle measurement method using CCD as photoelectric transformation element is feasible.