激光雷达多路距离测量系统设计

为了实现阵列激光雷达发射单脉冲激光瞬间3维成像,解决多路激光距离测量问题,采用并行处理架构设计了25路并行距离测量系统,由4个测量单元和1个复用单元构成1个多核并行处理机。每个测量单元包含8路跨阻放大器和8路高速比较器、1片TDC-GPX芯片和1个STM32处理器;复用单元由现场可编程门阵列实现多路测量数据打包,并通过USB2.0完成数据上传。结果表明,多路激光测距误差小于25cm;测量系统具有开放性,测量通道数易于扩展,子板可互换;并提出了按距离分段的误差校正方法,无须重复测量多次,可在单脉冲探测下直接校正测距数据。这为研制更高精度的阵列激光雷达系统奠定了一定的基础。

Design of multi-channel ranging system for lidar

In order to capture 3-D image instantaneously by transmitting single laser pulse of array lidar, solve the problem of multi-channel ranging, a 25-channel concurrent ranging system was developed. A multi-core parallel processor was consisted of four measuring units and one data multiplexing unit. Each measuring units contained 8-channel trans-impedance amplifiers, 8-channel high speed comparators, a TDC-GPX chip, and a STM32 microprocessor. Multi-channel data package and upload were completed by field-programmable gate array( FPGA) in multiplexing unit. Experimental results indicate that range error is less than 25cm. The ranging system has the feature of openness, ranging channel can be increased easily, and circuit boards are interchangeable. Error correction method based on distance is presented. The correction of ranging data can be accessed directly by single laser pulse detection without the repetition of measurement. The study gives the foundation for researching and manufacturing of array lidar with higher precision.