Research And Design Of Pulsed Laser Range Finder

Laser is widely used in various fields because of its good directivity, high brightness and good coherence. With the rapid development of several decades, the laser range finders have been applied in various fields. Therefore, the research of laser range finder is great significance in promoting the development of science and technology.After years of research, the laser pulse ranging technology has gradually developed into a more mature technology, the current development direction of laser range finder is miniaturization and high precision. Therefore, this paper makes a research on the requirement of miniaturization and high precision of laser ranging system.In this thesis, the several theories of common flight time laser ranging are analyzed, and the method of pulse laser ranging is selected as the main method. And a solution is put forward, which includes the pulse laser transmitting module, the photoelectric receiving module, the time identifying and time measuring module, the control module.In the pulse laser transmitting module, the high-speed logic gate circuit is adopted to generate the pulse signal, and the semiconductor laser diode is driven by a laser driven chip. The solution can be used to solve the problem of emitting laser stability, and it is easy to connect with the digital circuit. The high-speed logic gate circuit can ensure the output pulse has a good waveform.The photoelectric receiving module selects the PIN photodiode, and outputs the signal through the preamplifier. The photoelectric characteristic of PIN photodiode is better, and the preamplifier circuit of PIN photodiode is simpler. The time identification and time measurement module uses the characteristic of the received signal itself to identify the time, and then the TDC-GP22 measures the flight time of the laser. TDC-GP22 has the characteristic of high accuracy in time measurement, and can preprocess the data, which can reduce the burden of the main controller. The STM32 series microcontroller is used to control the whole system.The related test results show that the design of the photoelectric receiving module can basically meet the requirements of the laser pulse distance measurement, but the research and design of the whole construction should be further improved.