【作者】 王典；

【导师】 刘晋浩；

【作者基本信息】 北京林业大学 ， 森林工程， 2012， 博士

【摘要】 众多环境和人为的因素影响了林木联合采育机的作业效率。为发挥多功能林木采育装备作业范围大,林间路径通过性强,采育作业效率高的设计特点,急需缩短作业的间隔时间。因此,为解决目前的森林联合采育装备发展所面临的问题,优化采育作业操作,提高森林资源利用率,提出在采育作业的观察、识别阶段,建立非接触激光扫描测量系统,进行立木识别与定位、树径测量和立木间株距计算等研究,为获取采育目标立木的精确模型提供关键数据,为采育工作装置作业提供精准目标数据,为林业装备的林间地面作业行走提供导航和障碍物探测,最终为提升多功能采育装备的自动识别水平奠定技术基础,丰富应用于复杂环境辅助作业的理论和方法。研究工作以及所取得的重要结论主要有以下几个方面：1.概述了国内外激光扫描测量系统研究应用的现状,分析探讨了国外典型的激光扫描测量系统开发应用现状。通过汲取国外先进的研究经验,结合我国激光测量应用技术的研究现状及人工林采育作业环境,提出了适合我国国情、林情的多功能林木联合采育机非接触激光扫描测量系统的研究方案和技术路线。2.依据现有WCF-1型多功能林木联合采育装备的现有情况,选取LMS291型激光扫描仪作为非接触测量系统的核心部件,编制了激光扫描仪和上位机之间的通讯与控制软件。并根据联合采育机的作业参数,合理的配置了非接触测量激光扫描仪的作业参数,并采集了多组现场数据。3.基于Matlab软件,根据激光扫描仪输出数据的形式,分别采用基于腐蚀扩张聚类计算原理和差分计算原理编制特征提取滤波算法,滤除原始激光扫描数据中的背景噪声和其他非目标噪声,提取扫描目标立木等的表面轮廓数据。4.根据特征提取、噪声滤除后的扫描目标表面轮廓数据,假设所有目标横截面为标准圆,采用三角公式拟合和最小二乘拟合两种算法分别计算采育目标立木的直径,并根据计算结果与人工测量结果的比较,选择结果精度较高的最小二乘拟合法作为立木直径计算方法。5.林木联合采育装备作业的林地环境复杂,除采育目标立木外,还有可能存在其他可能影响采育作业的大型障碍物,如岩石,房屋、墙体等。为了避免采育工作装置的误操作,根据最小二乘法拟合目标直径的结果,采用一种基于多元统计分析的系统聚类方法对拟合目标直径结果数据进行分类,进而实现采育目标立木和大型障碍物的有效区分。6.由于多功能林木联合采育装备还要进行大量的抚育伐作业,需在林间行走,而立木间株距大小对于整车能否顺利通过有较大影响。本文通过激光扫描测量系统,获取采育作业林地内立木间的株距数据,为多功能林木联合采育装备驾驶员提供辅助信息,为联合采育装备在林地内的行走、避障、通过性和路径规划等进一步研究提供数据支撑。更多还原

【Abstract】 Many environmental and human factors greatly affected the operating efficiency. To express its features designed of large operation range, strong passing ability and high efficiency, it is urgent to curtail the time interval. Therefore, in order to solve the current problems, to optimize the cutting and cultivating operation, to improve the utilization of forest resources, forest recognition and observation, and to establish non-contact laser scanning system, we have to investigate the stumpage identification and position, diameter measurement and interval calculation so that to obtain critical data for the accurate model of target stumpage and to provide obstacle detection for operations during walking on forest land. Finally, it will lay the technical foundation for multi-function forest felling &cultivation equipment to enhance the level of automatic identification which can be profusely applied into theoretical research of auxiliary operations in complex environment.This paper mainly researched for non-contact laser scanning system theoretical research and applications in the forestry felling & cultivation machine. It mainly included severe aspects as follows:1. It summarized the current situation of laser scanning measuring system applications at home and abroad, analyzed and explored the typical foreign current situation of it.By bring in foreign advanced experience, combining with our research application situation and environment of cutting and cultivating operations, the research programs and technology route of multi-function forest felling & cultivation machine non-contact laser scanning system have been proposed, which were suited for China’s national conditions and forestry situation.2. In accordance with the existing situation of WCF-1 multi-functional forest felling &cultivation equipment, we selected the LMS291 laser scanner as a core component of non-contact measurement system, and have compiled the software of communication and control between the host computer and laser scanner. Meanwhile, according to operating parameters of the machine, the non-contact measurement was reasonably configured and many groups of field data were collected.3. According to the form of the laser scanner output data, based on Matlab and the filtering algorithm compiled by corrosion expansion and cluster calculation principle background noise and other non-target noise were filtered out in the original laser scan data so that we can obtain profile data of target stumpage, etc. 4. According to the profile data after being filtered, we assumed that all the objectives as the standard circle, and utilized the two algorithms of triangle formula and least-squares fitting to separately calculate the target stumpage diameter. In accordance with the results and its comparison with manual measurement, we chose the least squares fitting with high accuracy as the method for stumpage diameter calculation.5. For the complex environment of forest land, besides the target stumpage, there probably exist other large obstacles such as rocks, houses, walls, which may affcct the operation. According to the least squares method, we sorted the results data of target stumpage by Hierarchical cluster method based on multivariate statistics analysis in case of false operation of the device, and then we can effectively distinguish between the target stumpage and large obstacles.6 To operate a lot of tending felling, the multi-functional forest felling & cultivation equipment needs to walk in the forest. However, the row spacing of stumpage does a great influence on whether it can pass through successfully. In this paper, with the laser scanning system, we obtained the data of the stumpage row spacing in order to provide supplementary information for the operators, and to provide data support for the equipment walking, obstacle avoidance, passing ability, path planning and other further studies.更多还原