The Study Of The Laser Triangulation Measuring System Based On Single Lens

As one of no-contact-classical measurement methods, laser triangulation (LT) has a wide application in many fields even including the military. Presently, a lot of the domestic and foreign research institutes have an in-depth study in LT aiming to the high-degree accuracy, high stability and high environmental adaptability. In this work, the environmental adaptability has been improved by reducing the volume of the measurement system with the higher measurement accuracy. By analyzing the LT system, a LT system to measure optical path has been proposed using normal coaxial layout. Based on the direct-injection LT, a lens has been saved by using the characteristic of the beam splitter. The advantage of this method lies in reducing the volume of the measurement system, improving the environmental adoptability and simplicity for installation and employment. By contrasting with the direct-injection LT, the proposed method sustains the high measurement accuracy. Meanwhile, the measurement range has been enlarged and the measurement environment and the measurement procedure have also been simplified. However, the requirements for the power and the stability of the laser diode (LD) are increased. Thanks to the mature semiconductor laser technology, it is simply to find the suitable LD for the proposed method.To verity the effectiveness of this method, a data acquisition system is required. So a liner array CCD optoelectronic data acquisition system has been designed based on ADC+CPLD+FIFO+USB structure It converts the optical signal, which includes the information of the analyte, into electrical signal. Then the electrical signal is amplified, filtered, sampled and stored. Finally, it sent to the host computer by USB. Through the visuaJ interface of the host computer program, the data is processed and the results are displayed. Outside box is designed according to the requirements of the optical path layout. Meanwhile, optical and data acquisition system are integrated and closed in outside box.The effectiveness of the proposed method has been verified by experiment. The results show that duo to the influence of the system mechanical production and optical device parameter, the system measurement error is about17μm. With the increasing distance, measurement error will reach100μm. Meanwhile, duo to the influence of the LD power and the measurement environment, the operating range is smaller than500mm. In addition, the vibration parameter can be accurately measured when the vibration is in70mm and smaller than1OHz. If the optical device and mechanical production are suitable selected, the measurement performance can be further enhanced. The proposed system has a wide application, duo to small volume, simple product, installation and operation, and good environmental adaptability.