| Summary: | 碩士 === 國立彰化師範大學 === 機電工程學系 === 93 === Recently, two major research projects of the laser range finder which are phase and pulse method, were investigated。In general, the former is the short distance measurement with high resolution, and the latter is for long distance measurement. In this research we look at the high resolution and short position measuring. Therefore, the phase method will be presented.
A laser range finder has two major parts which are the optical and signal process systems. Our focus will be on the signal process in this research. The presented system consists of the laser driver circuit , frequency generating circuit, opto-detecting circuit, and the display circuit。From our studies the high resolution laser range finder with the superheterodyne method by means of missing and knocking down the frequency were presented.
Firstly, the photo-detector receives the laser beam emitted by the auto-power control circuit, and it loads a signal that is generated by the frequency generating circuit with 100 MHz. Secondly, the frequency generating circuit also obtains a signal at 9.99 MHz, and both of receiver and emission have a 10 kHz signal frequency difference between the 10 MHz and 9.99 MHz. Finally, the phase meter counts the phase difference in phase between emission and receiver, and then it would display on the LCD.
|
|---|
