脉冲激光测距漂移误差的研究

Study on Walk Error in Pulsed Laser Range-Finding

光脉冲接收是脉冲激光测距的关键技术之一。稳定有效地探测反射激光脉冲信号和提高脉冲激光测距仪的环境抗干扰能力 ,是光脉冲接收技术需解决的主要问题。对 PIN光电二极管的光探测过程进行了理论分析。指出PIN管中的光生载流子和耗尽层电荷的相互作用导致了耗尽层宽度的改变 ,进而引起 PIN管的光接收响应时间的变化。结合半导体基本理论 ,构建了相应的 PIN管光探测过程理论模型 ,定义两个描述 PIN结性能的特征参数 :单位光功率敏感度 K和单位时间抖动Δτp 0 ,进一步给出了 PIN管的光响应时间及其抖动大小与光照强度的近似函数关系。该理论模型成功用于解释自触发脉冲激光测距中的漂移误差现象 ,经过对实验现象和相应实验结果的定性分析 ,验证了理论分析的正确性。

The reception of laser pulses is one of the key technologies in the laser rangefinding. The stable and effective detection and the increased ability of anti-jamming are the main problems to be solved. In this paper, an elementary study on walk error in pulsed laser range finding is carried out. The photodiode response time is affected by the change of depletion layer width, which is caused by the interaction between depletion layer charges and photo-induced carriers. The basic theoretic model is set up to explain this process, and two characteristic parameters unit optical power sensitivity K and unit time jitter Δτ_ p0 are introduced. The approximate relation between the photodiode response time, its jitter and the laser pulse power projected on the detector is obtained respectively, which are successfully employed to explain the walk error phenomena in the self-triggering pulsed time-of-flight laser rangefinding experiment.