Study On Laser Range Finding Technology In Total Station Laser Alignment System

Recently, the measuring approach by the means of alignment laser beam as the linear references has been greatly promoted. Laser alignment technology has been widely used in shape error measuring, such as linear, concentricity, flatness and parallelism. However, conventional laser collimators are incapable of obtaining distances of measuring points directly, which cause great inconvenience of measuring and data processing. Especially, in automatic measurement, distance information of the measuring point is necessary.Contra pose this deficiency of the conventional laser collimators, total station laser alignment system is designed. The system combines the portable laser interference collimator and laser range finder. In the laser alignment part, an aligned and enlarged laser beam is projected to optical wedge plate. Optoelectronic device is used to detect interference fringes created by reflected laser of front and back surface of the plate. Through signal processing, the movement of the interference fringes is obtained. Then the deviation of the target from the collimation beam is measured. In the laser range finding part, modulated laser is reflected by the cooperation target opposite. Phase difference of the emitted laser and the reflected laser is obtained by signal processing. Then the distance is measured by calculation. The total station laser alignment system have both the function of laser collimator and laser range finder, and measured data is transmitted to computer via wireless data transmission system for further data processing and display in the computer interface.The basic architecture, theory, hardware and software design of total station laser alignment system is introduced. Methods of laser range finding are discussed. Based on the characteristic of short distance measurement, the approach of phase laser range finding is selected. The hardware and software of the laser range finding system is designed.Several experiments of are performed. The possible error sources are analyzed. The results indicate that the distance measurement error is below±5cm and the system can function well and the performances have met the scheduled targets.