摘要
机载激光雷达多采用单束激光,通过扫描的方式完成对目标的探测。通常,由于扫描机构的缺陷,激光脚印在地面上的分布是不均匀的,而均匀扫描方式可提高激光雷达图像反演的质量,但在实现上存在一定的难度。首先从理论上分析了实现均匀扫描应满足的关系式,进而给出了一种工程实现的方法。电机输入曲线以理论推导的关系式为基础,在扫描视场边缘,通过曲线拟合,对理论曲线进行平滑,降低扫描输入曲线中的高次谐波分量。在测得振镜幅频特性曲线的基础上,利用迭代算法得出曲线拟合过程中的参数。与其他方法相比,该方法可以根据给定的扫描频率和视场角,自动计算出最佳电机输入曲线,从而在工程应用中,能够灵活地改变扫描参数。模拟实验结果表明,应用该方法扫描,激光点分布均匀,线性度良好。
Airborne lidar is used to detect a target by scanning with a single beam of laser. Generally,the distribution of the laser footprints on the ground is not uniform due to the flaw of the scanning mechanism. In the fact,it is more difficult to give the better quality of the image inversion for the uniform scanning than the non-uniform scanning. Firstly,the formula of the uniform scanning of the airborne lidar was discussed and a method to achieve the uniform scanning was given. The input waveform of the scanning motor was based on the formula in the middle of the view field. While on the edge of the view field,the polynomial fit was used to smooth the waveform and reduce the harmonic content. The parameters of the fit process were determined by the iterative way on the basis of frequency response of the galvanometer measured from the experiment. Compared with other methods,the proposed method can automatically give the optimal input waveform of the scanning motor based on the given scanning frequency and view field angle,so that the scanning parameters can be changed easily in engineering applications. The simulation test results show that the scanning system can achieve the uniform distribution and the good linearity of the laser points by using the proposed method.
出处
《红外与激光工程》
EI
CSCD
北大核心
2008年第4期675-678,共4页
Infrared and Laser Engineering
基金
国家863计划资助项目(2007AA12Z105)
关键词
均匀扫描
激光扫描
激光雷达
振镜
Uniform scanning,Laser scanning,Lidar,Galvanometer
