At present, driverless technology has become the development trend of automobile-dominated cities, and obstacle detection is a sub-important link in driverless technology. As a main arrival detection method, laser arrival detection has the advantages of fast measurement speed and high precision, and has obvious advantages in obstacle detection. In this paper, obstacle detection of unmanned vehicles is the most important application. Aiming at the shortcomings of scanning multi-line radar, such as high cost and low ranging accuracy, the laser ranging technology is studied, and according to the vehicle environment and practical application requirements, the scanning ranging laser provincial station system is designed. The main work of this paper is as follows:

(1) The principles of pulse laser ranging and phase laser ranging are compared and analyzed. According to the real-time detection of obstacles in unmanned vehicles.

According to the requirements, the pulse ranging scheme is selected, and the key factors affecting the pulse measurement accuracy are comprehensively tested. An improved time identification and time interval measurement method is designed to optimize the acquisition and measurement performance of the system.

(2) According to the specific characteristics of semiconductor laser and photodetector, the optical system of transmitter and receiver is designed, and the ray tracing simulation is carried out in zEMAx software, which verifies the collimation compression of the transmitted beam and the effective focusing of the echo beam, thus improving the detection range and accuracy of the system.

(3) The circuit system of narrow pulse laser transmitting and signal receiving is designed and built. The system is based on FPGA devices and

As the main controller, C805 1F206 single chip microcomputer can realize narrow pulse laser with repetition frequency of 1kHz and pulse width of 60ns.

Radiation: In order to improve the signal-to-noise ratio of the receiving system, APD with high sensitivity is selected as the photoelectric detector, and combined with the signal for electrical conditioning.

Road, so as to realize the effective extraction of weak echo signal: design high-precision time difference measurement module and mechanical rotation module to verify the ranging performance of scanning laser radar system.

(4) In order to verify the performance of ranging lidar in obstacle detection of driverless cars, it is implemented in Visual Studio 20 10.

The data reconstruction interface based on MFC is developed under this platform, and the obstacle information reconstruction is realized according to the measured distance quotient data.

Build an experimental platform, measure close-range targets, verify the detection performance of the prototype system and the final results.

It shows that the designed pulse lidar system basically meets the expected detection requirements and has certain practical application value.