【作者】 陈建；

【导师】 王树勋；

【作者基本信息】 吉林大学 ， 信号与信息处理， 2004， 硕士

【摘要】 本论文主要对激光电子白板的定位方法进行了研究，完成了整个激光电子白板的硬件电路的设计与实现，并运用DSP对定位算法进行了实现，完成了激光电子白板的基本书写功能，弥补了国内在激光定位电子白板研制方面的空白。激光电子白板采用激光扫描的方法实现对书写笔实时跟踪定位。激光电子白板能够实现彩色笔迹书写和擦除，具有实时性好和精度高等优点。电子白板是一种替代传统的黑板、粉笔的新型数字化教学工具，是对黑板、粉笔、板擦 "三位一体"的陈旧教学、会议模式的一场革命性突破。它融入了数字处理、多媒体、远程教学、远程会议等元素，克服了传统方法的弊端，是网络时代计算机辅助教学的理想选择。现今大、中、小学仍在用黑板作为教学的主要工具，由于所用的粉笔会带来粉尘，影响了教学人员的身心健康。现在大部分会议室或办公室用白板代替了黑板，用白板笔在白板上书写,可以解决粉尘带来的麻烦。然而，普通白板同黑板一样，它不能捕捉书写板面上的文字和图画成为电脑文档保存在电脑中，仍需要会议人员记录会议的内容，也不能使在其它办公室、会议室（不管是否在同一建筑物、城市，还是在世界各地）的人员通过网络进行信息交流、共享会议信息。然而电子白板能够很好弥补上述普通白板的不足。电子白板在欧美已经得到广泛的应用。在国内，这几年电子白板也在大多数教室，会议室，宾馆，报告厅等场合得到很好的应用。目前国内已研制出扫描式电子白板、触摸式电子白板和基于超声定位的无线定位电子白板。我们实验室在基于无线定位理论的基础上，已成功研制成基于超声波信号定位的多功能交互式无线定位电子白板。基于超声信号定位的无线定位的电子白板虽然有诸多优点，但是由于超声信号的频率较低，在实际应用场合极易受到其它尖锐声音信号的干扰。而激光信号在实际应用中就不易被干扰，激光作为电磁波的一种，以其自身独有的特点，广泛应用与现代工业、农业、医学、通讯、国防等方面。以激光信号作为定位信号的激光电子白板具有定位精度高，抗干扰能力强<WP=84>以及稳定性好等优点。激光电子白板是在校准系统的配合下利用两个激光扫描器扫描定位目标，根据定位目标反射的激光信息获得两个激光扫描器的扫描角度，根据扫描角度计算出定位目标在书写板面的坐标，实现对定位目标的定位。本文的主要工作及其内容安排如下：第一章简要介绍了国内外电子白板的研制和开发历史及其现状，阐述了研制激光电子白板的开发背景，以及激光电子白板的基本组成。第二章针对远场与近场定位的多种方法进行了研究与论证，提出了激光电子白板的定位方法。第三章完成了激光电子白板的书写系统和校准系统的设计与实现，同时实现了书写笔颜色信息以及板擦信息的识别。第四章设计了激光电子白板的激光扫描系统，并对激光发射和接收的光学系统进行了实现。第五章对激光电子白板系统的硬件电路进行了设计与实现。第六章完成可激光电子白板的定位算法的DSP实现，同时给出了计算结果的误差分析以及DSP、单片机软件的控制流程。第七章对全文进行了总结，指出今后的工作和待研究的方向。本文的主要贡献在于：（1）总结和归纳远场定位的方法种类，近场定位方法方面则主要介绍基于无线定位电子白板的几种算法。（2）提出激光电子白板的定位算法，即基于激光扫描的定位方法。（3）激光信号的产生与激光二极管的自动功率控制，激光扫描光学系统的设计与实现。（4）激光电子白板硬件电路系统的自动增益调整。（5）激光电子白板的硬件电路的设计、实现、系统复杂逻辑控制以及定位算法的实现。激光电子白板的研制工作，有几个问题待解决：（1）激光扫描系统的光学系统的优化。（2）寻求合理的光学系统调试方法和检测方法。（3）不同环境因素对激光电子白板影响的研究。更多还原

【Abstract】 The work of this paper focuses on design and realization in hardware part of the laser electronic whiteboard. It studies the location method of the laser electronic whiteboard and realizes basic function of laser electronic whiteboard.The laser electronic whiteboard adopt the method of laser scanning for tracking the writing pen. It supports colorized pens writing and erasing. It is provided with real-time performance and high precision.Electronic whiteboard is the modern equipment which will replace the traditional blackboard and chalk. It is the renovation of the old teachering and meeting mode. Which embodies digital processing, multimedia, long-distance education, netmeeting and overcomes disadvantage of the traditional means, electronic whiteboard is perfect choice of the Computer Aided Education. Nowadays, blackboard is still main tools of teaching in primary schools, middle schools, and colleges. But the dust which the chalk carries may affect teachers and students’ health. The general whiteboard solves the problem, but same to the blackboard, it can not capture and save pictures and words on the board. As the electronic whiteboard appears, this sort of whiteboard solve the problem capturing and saving handwriting on board, in this way, students attending class and people who take part in conference do not needed to note anything strenuosity, thereby, the electronic whiteboard has sufficient application in America and Europe. In our country, the electronic whiteboard has sufficient application in lots of classrooms, auditoriums and hotels in recently years.Now, there are the scanning electronic whiteboard, the touching electronic whiteboard, and the electronic whiteboard based on wireless location and so on. The wireless location electronic whiteboard based on ultrasonic signal has many advantages, but this type electronic whiteboard is easily interfered by aculeated sound signal because the frequency of the ultrasonic signal the frequency is lower. Yet, the laser signal is infrequently interfered. The laser whiteboard based on laser signal as location signal have high precision, real-time performance and good stability.Cooperated with calibrating system, the laser electronic whiteboard uses two laser scanners to scanning the writing pen or eraser and utilizes the reflecting laser to obtain the scanner angle of the two laser scanner, then uses the two scanner angle to calculate the pen’s or eraser’s coordinate. The main work and contents are summed up as follows. <WP=86>The dissertation consists of seven chapters. In chapter one, it is summarized that the electronic whiteboard’s development history and actuality all over the world, and the significance of exploiting laser electronic whiteboard and laser electronic white board’s configuration have been introduced. In chapter two, some methods about near field’s and far field’s location have been introduced, the location algorithm of laser electronic whiteboard has been explained in detail.In chapter three, the design of the writing system and calibrating system has been summarized, identifying the information of writing pen’s color and eraser also has been introduced.In chapter four, the constitution of laser scanning system has been introduced. Then the system of laser emission and the system of laser receive has been explained in detail.In chapter five, according as the main function of each part of the hardware, the design and realization of the hardware has been analyzed in especially. In chapter six, the realization of the algorithm of the electronic whiteboard using DSP has been introduced. The result’s error of calculation, the software of DSP and monolithic processor have been discussed respectively.In chapter seven, it is summarized that the contribution and deficiency of the system.The main contribution of this paper is listed as follow:Ⅰ The electronic whiteboard actuality on domestic and overseas is summed up, the location methods and sorts on near field and far field are summarized. Ⅱ It更多还原