Development of a laser range finder using the phase difference method

摘要

Making a map by using global sensor information is a mainstream tool in a mobile robot's navigation. It requires specific vision system such as a CCD camera, range finding system, and many other things. A laser range finder has highly collimated beams that can be obtained easily, thus achieving high lateral resolution, and the short wavelengths involved cause the light to be backscattered, rather than reflected by the target. For signal processing, the phase difference method using frequency modulation/demodulation is addressed in this paper. We used a diffused reflected beam to detect the phase shift in this system. But this beam has a minute signal and can be easily buried in nose. A modulation/demodulation method is used to measure the signals which are buried in noise.