| 题名: | 基于时幅转换插入法的脉冲激光测距系统研究 |
| 作者: | 周武林
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| 学位类别: | 硕士
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| 答辩日期: | 2008-06-06
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| 授予单位: | 中国科学院光电技术研究所
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| 授予地点: | 光电技术研究所
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| 导师: | 岳永坚
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| 关键词: | 脉冲激光测距
; 时间间隔测量
; 时幅转换
; 数字计数
; 插入法
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| 其他题名: | Pulsed laser ranging system research on the interpolation method of time-to-amplitude conversion
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| 学位专业: | 检测技术与自动化装置
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| 中文摘要: | 针对脉冲激光测距数字计数法精度低的问题，本文介绍了用时幅转换插入法来提高脉冲测距系统时间分辨率和测距精度的原理及技术途径，并设计了基于时幅转换插入法的脉冲激光测距系统，包括激光发射电路，激光接收电路，时间测量电路和微控制器部分。激光发射电路由半导体激光器和集成驱动芯片组成，产生了具有高峰值功率和快速上升时间的光脉冲信号；在激光接收方面，采用雪崩光电二极管APD作为探测器，选择低噪声高带宽跨阻型前置放大器和电压增益控制放大器组成信号放大电路，并设计了恒比定时时刻鉴别电路。时间测量电路由FPGA数字部分和模拟时幅转换插入部分组成。在FPGA中，实现时钟倍频，高频计数器和时序控制逻辑等功能；在模拟时幅转换插入部分电路中，时间间隔脉宽由电容恒流放电线性转化为电压幅度，经过A/D模数转换器测量，实现了时间周期细分，提高了时间分辨率。在微控制器方面，主要实现测距时序控制，测距数据结果的读取和传输，并用查表法和D/A转换器实现压控放大器的增益控制功能。测距数据结果通过串口传输显示在上位计算机上。最后，对脉冲激光测距系统进行了实验测试，得到了实验结果，并进行了误差分析。实验结果表明，基于时幅转换插入法的脉冲激光测距能够将测距精度由米级提高到厘米级。 |
| 英文摘要: | Traditional pulsed laser ranging with direct counting time measurement has low precision. In order to improve time resolution and precision of pulsed laser ranging, the interpolation method of time-to-amplitude conversion (TAC) is introduced in this paper. According to the time measurement principle, a pulsed laser ranging finder is designed, which is constructed of laser transmitting circuit, laser receiving circuit, time interval measurement unit and microcontroller. The laser transmitting circuit can produce laser pulse with high peak value power and short rise time, which includes semiconductor laser diode and integrated laser driver chip. In laser receiving circuit, an avalanche-photo-diode (APD) is used as detector. The signal amplifier circuit is composed of preamplifier and postamplifier. The preamplifier has low noise and broad band width of frequency. The gain of postamplifier can be adjusted by control voltage. The Constant Fraction Discriminator (CFD) is designed here. The time interval measurement unit includes Field Programable Gate Array (FPGA) digital device and analog TAC interpolation circuit. In FPGA, the functions of clock frequency multiplication, high frequency counter and sequential control logic are achieved. In analog TAC interpolation component, the time interval is converted to voltage amplitude by capacitor constant current discharging and then measured by A/D convertor. The process divides the time period and improves the time resolution. The ranging sequential control, data read and transmission and gain control with look-up-table method and D/A convertor, are achieved in microcontroller. The ranging data results are displayed on computer by serial port communication. In the end, the pulsed laser ranging finder is tested in experiment. The experiment results are ginven and the error of ranging system is analyzed. The experiment result shows that the precision of laser range finder with this method can be improved to centimeter level. |
| 语种: | 中文
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| 内容类型: | 学位论文
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| URI标识: | http://ir.ioe.ac.cn/handle/181551/332
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| Appears in Collections: | 光电技术研究所博硕士论文_学位论文
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| 10001_200528015128052周武林_paper.pdf（1758KB） | -- | -- | 限制开放 | | View
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| Recommended Citation: | |
周武林. 基于时幅转换插入法的脉冲激光测距系统研究[D]. 光电技术研究所. 中国科学院光电技术研究所. 2008.
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