【作者】 董斌；

【导师】 王省书；

【作者基本信息】 国防科学技术大学 ， 光学工程， 2011， 硕士

【摘要】 针对扫描成像激光雷达对高分辨率二维激光扫描的需要,论文对用于成像激光雷达的线扫描振镜的关键技术进行了研究。论文分析了现有转镜式激光扫描器垂直像素数较低的限制因素,提出了在系统中增加一个一维线扫描振镜以提高扫描图像垂直像素数的改进方案。通过对激光扫描器工作原理的分析提出了线扫描振镜的设计指标,给出了线扫描振镜的总体设计方案。采用机械控制综合设计的方法完成了振镜机械结构和控制系统设计。论文对振镜系统中的控制对象、控制器、测量噪声、驱动饱和等因素进行了仿真建模,根据仿真模型分析了振镜机械参数对系统关键性能的影响,对反射镜和柔性支撑的机械设计方案进行了优化。同时针对控制对象机械谐振频率较低的特性,提出了基于零极点对消方法的控制器设计方案。论文利用振镜样机对设计方案进行了实验验证。利用LabVIEW和数据采集卡构建了虚拟仪器系统,对控制对象的频率特性进行了测量,根据测量结果拟合得到了控制对象的传递函数。根据辨识结果完成了控制器设计和系统闭环实验。实验结果表明:虚拟频率特性测量系统能够准确辨别控制对象的频率特性,使用串联校正的方法抑制了机械谐振的影响,使系统的开环穿越频率接近控制对象的机械谐振频率,系统闭环带宽达到约100Hz,扫描线性度与开环系统相比有了明显改善。实验证明振镜的设计方案是可行的。论文的研究工作为线扫描振镜和高分辨率激光扫描器的研制奠定了基础。更多还原

【Abstract】 The critical technology and related theory of oscillating mirror laser scanner are discussed in detail in this dissertation. The problem of existing rotating mirror scanner is analyzed in general, and an improved project of 2-D laser scanner is proposed for higher resolution in vertical direction.The improved laser scanner is composed of existing rotating mirror and adding oscillating mirror. According to the principle of improved scanner and the function of oscillating mirror, the performance specifications of oscillating mirror scanner are proposed.The mechanical design which is characteristic of flexure and voice coil actuators is discussed using integrated mechanical-control design method, after analyzing and comparing optional projects. The mechanical design of reflecting mirror is analyzed and determined with compromise between weight and stiffness. The mechanical stiffness of the flexure is discussed and determined for optimization of overall system performance and facility of controller. The flexure mechanical design and controller prototype are proposed.Experimental researches are implemented to examine the feasibility of scanner design. Virtual instruments based on LabVIEW and USB 6229 are developed for transfer function identification. The transfer function model is built according to the frequency characteristic and working mechanism of the control object. With comparing to commercial dynamic signal analyzer, the VIs have the same performance and lower cost. With the high accurate transfer function, cascade compensator is designed to eliminate the mechanic resonance of control object. The compensator is implemented on embedded computer system and closed-loop experiment is completed. Experiment result shows that with the compensator added to the forward path, the system closed bandwidth is expanded effectively to about 100Hz, exceeding mechanic resonance frequency. The feasibility of the design is proved by the experiment.更多还原