Research On High Precision Phase Measurement Technology In Hand-held Laser Ranger

Owing to the advantages of high precision and long distance detect, the laser ranger is widely used in the fields of distance measurement. Hand-held laser ranger, as a result of introducing the principle of phase measurement, has much good qualities as higher precision, easy hold, it has a wide application potential. The high precision phase measurement technology in Hand-held laser ranger is greatly studied.Firstly, a summary of all kinds of laser ranging technology and their development trend are made. On basis of analyzing the problemes of laser ranging technology existing, as the main content of this thesis, the high precision phase measurement technology applied to the Hand-held laser ranger is proposed.Secondly, the principle of Phase-laser ranger and the special requirement for phase measurement in Hand-held laser ranger are discussed. The working parameters of the designed Hand-held laser ranger are selected based on the principle of phase laser ranger. The hardware based on digital phase measurement and the combination of digital phase measurement and analog interpolating phase measurement has been designed. The two methods and the errors of the phase measurement are analyzed through the experiment.Phase measurement technology by means of digtial signal processing is studied for improving the measurement precision. The theory of phase measurement methods using correlation detection and FFT spectrum analyzing is introduced. For solving the existing problem in sine signal phase measurement, the method based on triangular signal correlation detection in phase measurement is investigated, and periodic triangular cross-correlation function has been induced. Simulation and experiment are carried out on phase measurement methods of using correlation detection and FFT spectrum analyzing, and the error is analyzed. The result of the experiment shows that the phase measurement precision using FFT spectrum analyzing achieved 0.1°, and it is much easier to realize for the phase measurement method based on periodic triangular signal correlation detection comparing with sine signal, but the precision need improving. Finally, the work is summarized and expected.