【作者】 张秀达；

【导师】 严惠民；

【作者基本信息】 浙江大学 ， 光学工程， 2008， 博士

【摘要】 三维主动光学探测技术或三维激光激光雷达技术是一种可以获得目标三维空间信息的新型光学探测技术,目前已经广泛应用在目标识别、机器人视觉、地形勘测、三维物体建模等各个领域。三维主动光学成像技术在远距离探测上较其他的三维探测技术有速度快、分辨率高和可靠性高的优点。三维主动光学成像技术作为一种新型的三维探测技术本身还在发展之中,理论基础也在建立之中。本论文在理论上分析了影响三维探测性能的因素,提出并实现了新型的三维探测方法与系统。从光源上将已有的三维主动光学成像系统划分为连续光源三维成像系统和脉冲光源三维成像系统。从光源、光传播介质、目标、背景和光电接收器等方面分析了影响以上两种三维成像系统性能的因素。从信息学的角度,分析了已有的三维主动光学成像系统的性能,提出了测距极限分辨率的概念。通过对连续光源三维成像系统的分析,从优化光源调制方式角度提出了半波相关鉴相法,将测距极限分辨率提高了28%～50%。通过将间接差频测距概念引入连续光源三维成像系统,提出了数值差频三维测距法,将绝对测距量程提高到原来的3倍。从补偿后向散射光功率的角度出发,提出了后向散射实测法来消除后向散射光的影响。新方法扩展了连续光三维探测的应用范围。通过对脉冲光源三维成像系统的分析,通过测距原理上的创新提出了脉冲形状无关的高线性度超测距分辨率三维成像方法。解决了原有超测距分辨率脉冲光源三维成像系统对光脉冲要求极高的问题。从而拓展了可使用的光源范围,使三维成像在远距离探测方法具有更大的发展空间。研制的峰峰值达6A的高频交流驱动电路,实现了对5W连续单管半导体激光器的3MHz调制。研制成峰峰值达600V的谐振高频驱动电路,实现了对像增强器的方波调制。研制了高精度的高频控制电路,频率稳定性好于0.015%,相位稳定性好于0.5%。研制成功基于新方法的连续光源三维成像系统。三维成像获得的图像像素数为800×600,最高帧率为15帧每秒。实验表明该系统在50米景深内的测距精度为0.26米,200米处测距精度为1.2米。研制的峰值电流达180A、脉冲宽度最窄为80ns、重复频率最高50KHz、工作电压最高60V的脉冲电流驱动电路,实现峰值功率864W、平均功率功率16.8W的激光脉冲输出。研制成最高重复率为100KHz、边沿时间50ns的低电磁干扰门驱动电路,实现了对光电接收器的门选通驱动。采用恒压驱动法实现了像增强器的线性时间增调制。研制的时间抖动小于1ns,可2ns步进时间差的双路驱动信号输出。实现了基于新方法的脉冲光源三维成像系统。三维成像获得的图像像素数为800×600,最高帧率为15帧每秒。实验表明系统的测距范围可达1千米以上,距离分辨率好于两米。更多还原

【Abstract】 Three-dimensional (3D) active optical detection technic or 3D laser detecting and ranging (LADAR) technic is a new optic detection technic which obtains full space information. It has been widly imployed in target identify, roborts vision, terrain reconnaissance, 3D modeling, etc. Compare with other 3D active optical detection technics 3D active optical imaging technic has merits of high speed, high resolution, and high reliable. As a new 3D detection technic, 3D active optical imaging technic is still straight forward. The theory foundation of 3D active optical imaging technic is still developing. This dissertation analyses the factors which influence the performences of 3D active imaging systems, presents the new 3D active optical imaging methods and systems.From the point of light source, the 3D active imaging system is consist with continouse wave light source 3D imaging system (CW3DIS) and pluse light souce 3D imaging system (P3DIS). Light source, targets, background and photoelectronic receiver are analized as the factors which influence the performences of 3D active imaging systems. The performances of 3D active optical imaging systems are also analized form the informatics point. The conception of distance detection limited precision is preseted.By the analisis of CW3DIS, half-wave correlation phase discrimination 3D imaging method with a performance 28%～50% higher than traditional method is present from the point of optimizing modulation style of light source. By the import of indirect differential frequences conception, numeric differential frequences method with improves the absolute measurement distance 1 times is present. From the point of amend backscatter light power, backscatter light power meausurement method is presented. The new methods expand the applicable areas of the CW3DIS.By the analisis of P3DIS, pluse-shape-free 3D imaging method with high linear accuracy and supper-resolution depth measurement is presented from an innovation of distant measurement principle. By this method, the question of the high quality pulse shape demended from the 3D imaging system with supper-resolution depth mapping is raveled out. The confine of light sources is expanded and the development space of 3D imaging system is extended.A drive circuit with a 6A apex to apex value drive current is developed. A 3 MHz modulation for a single laser diode (LD) with 5 W output power is realized. A drive circuit with 600 V apex to apex value drive voltage is developed. Square wave modulation for photoelectric receiver is realized. A control circuit with high precision frequences is developed, the stable of the frequences is better than 0.015%, the stable of phase is better than 0.5%. A CW3DIS based on new method is developed. The imaging system has an array of 800×600 pixels and an imaging rate of 15 frames per second. 3D imaging experiment results show that the distance precision is 0.26 meters at a depth of 50 meters and the distance precision is 1.2 meters at a distance of 200 meters.A drive circuit with 180 A pex current, 80 ns minimum pluse width, 50 KHz maximum repetition, and 60 V maximumu work voltage is developed. Pex 864 W output light power and average 16.8 W output light power is realized. A drive circuit with 100 KHz maximum repetition, 50 ns eadge time and low electromagnetic disturbance is developed. A gated photoelectric receiver is realized. Linear increase modulation of the image intensifier is realized by constant voltage drive method. A control circuit with less than 1 ns jitter and 2 ns step differencial delap between two drive signals is realized. The imaging system has an array of 800×600 pixels and an imaging rate of 15 frames per second. 3D imaging experiment results show that the measurement distance is longer than 1 kilometer and the distance resolution is better than 2 meters.更多还原