Fast and accurate measurement of the volume of earthmoving materials is of great signifcance for the real-time evaluation of loader operation efciency and the realization of autonomous operation. Existing methods for ...Fast and accurate measurement of the volume of earthmoving materials is of great signifcance for the real-time evaluation of loader operation efciency and the realization of autonomous operation. Existing methods for volume measurement, such as total station-based methods, cannot measure the volume in real time, while the bucket-based method also has the disadvantage of poor universality. In this study, a fast estimation method for a loader’s shovel load volume by 3D reconstruction of material piles is proposed. First, a dense stereo matching method (QORB–MAPM) was proposed by integrating the improved quadtree ORB algorithm (QORB) and the maximum a posteriori probability model (MAPM), which achieves fast matching of feature points and dense 3D reconstruction of material piles. Second, the 3D point cloud model of the material piles before and after shoveling was registered and segmented to obtain the 3D point cloud model of the shoveling area, and the Alpha-shape algorithm of Delaunay triangulation was used to estimate the volume of the 3D point cloud model. Finally, a shovel loading volume measurement experiment was conducted under loose-soil working conditions. The results show that the shovel loading volume estimation method (QORB–MAPM VE) proposed in this study has higher estimation accuracy and less calculation time in volume estimation and bucket fll factor estimation, and it has signifcant theoretical research and engineering application value.展开更多
To break down the development interaction of the working gadget of the multi-practical wheel loader and to compute the heap of each part, the Denavit-Hartenberg strategy was applied to build up the kinematics of the i...To break down the development interaction of the working gadget of the multi-practical wheel loader and to compute the heap of each part, the Denavit-Hartenberg strategy was applied to build up the kinematics of the instrument model. Also, all the while, set up the elements model of dynamic framework. A multi-body element programming MSC, ADAMS and its active module were applied to assemble component power through a pressure framework reenactment model. An entirety working cycle interaction of the functioning gadget of the wheel loader was mimicked, and the investigation results thoroughly show the development interaction of the functional device and the stacked state of each part, and check the mechanical properties of the working gadget and dynamic execution water-driven framework effectively.展开更多
对统一可扩展固件接口(UEFI)的体系架构和执行流程进行安全性分析,发现Windows启动过程中EFI OS Loader的可信性校验存在安全漏洞,其可导致Windows启动流程被劫持。针对该安全漏洞,从文件分离保护、开机身份认证和系统关键区域防护3个...对统一可扩展固件接口(UEFI)的体系架构和执行流程进行安全性分析,发现Windows启动过程中EFI OS Loader的可信性校验存在安全漏洞,其可导致Windows启动流程被劫持。针对该安全漏洞,从文件分离保护、开机身份认证和系统关键区域防护3个层次出发,提出了一种基于USB Key启动、动态口令手机令牌和EFI安全防护软件的三层安全加固的方案。将EFI OS Loader文件存放在USB Key中并加密,实现对文件的保护;把动态口令认证服务端置于USB Key中,两者的有机结合实现了高强度的开机身份认证;设计并开发了遵循UEFI规范的EFI应用程序型安全防护软件,实现了对系统关键区域的保护。实验结果表明,该方案的双认证与安全防护机制弥补了相关安全漏洞,增强了计算机系统启动过程的安全性。展开更多
文章提出一种基于ARMll的Windows CE 6．0引导程序（Bootloader）设计与实现方法，通过分析Bootloader架构，在解析系统镜像文件和研究DownloaderImage下载函数的基础上，设计并实现一种基于Samsung6410的Windows CE6．0的Bootloader。...文章提出一种基于ARMll的Windows CE 6．0引导程序（Bootloader）设计与实现方法，通过分析Bootloader架构，在解析系统镜像文件和研究DownloaderImage下载函数的基础上，设计并实现一种基于Samsung6410的Windows CE6．0的Bootloader。重点阐述了其控制引导和下载镜像文件的开发过程，并给出了下载镜像函数的编程模型和算法框架。测试结果表明，该Bootloader支持通用的系统镜像文件（．bin）的下载，能够达到预期的设计目标并已应用于一款基于Samsung6410处理器的IPTV手持式测试仪系统上。展开更多
基金Supported by National Key R&D Program of China(Grant Nos.2020YFB1709901 and 2020YFB1709904)National Natural Science Foundation of China(Grant Nos.51975495 and 51905460)+1 种基金Guangdong Provincial Basic and Applied Basic Research Foundation(Grant No.2021A1515012286)Guiding Funds of Central Government for Supporting the Development of the Local Science and Technology(Grant No.2022L3049).
文摘Fast and accurate measurement of the volume of earthmoving materials is of great signifcance for the real-time evaluation of loader operation efciency and the realization of autonomous operation. Existing methods for volume measurement, such as total station-based methods, cannot measure the volume in real time, while the bucket-based method also has the disadvantage of poor universality. In this study, a fast estimation method for a loader’s shovel load volume by 3D reconstruction of material piles is proposed. First, a dense stereo matching method (QORB–MAPM) was proposed by integrating the improved quadtree ORB algorithm (QORB) and the maximum a posteriori probability model (MAPM), which achieves fast matching of feature points and dense 3D reconstruction of material piles. Second, the 3D point cloud model of the material piles before and after shoveling was registered and segmented to obtain the 3D point cloud model of the shoveling area, and the Alpha-shape algorithm of Delaunay triangulation was used to estimate the volume of the 3D point cloud model. Finally, a shovel loading volume measurement experiment was conducted under loose-soil working conditions. The results show that the shovel loading volume estimation method (QORB–MAPM VE) proposed in this study has higher estimation accuracy and less calculation time in volume estimation and bucket fll factor estimation, and it has signifcant theoretical research and engineering application value.
文摘To break down the development interaction of the working gadget of the multi-practical wheel loader and to compute the heap of each part, the Denavit-Hartenberg strategy was applied to build up the kinematics of the instrument model. Also, all the while, set up the elements model of dynamic framework. A multi-body element programming MSC, ADAMS and its active module were applied to assemble component power through a pressure framework reenactment model. An entirety working cycle interaction of the functioning gadget of the wheel loader was mimicked, and the investigation results thoroughly show the development interaction of the functional device and the stacked state of each part, and check the mechanical properties of the working gadget and dynamic execution water-driven framework effectively.
文摘对统一可扩展固件接口(UEFI)的体系架构和执行流程进行安全性分析,发现Windows启动过程中EFI OS Loader的可信性校验存在安全漏洞,其可导致Windows启动流程被劫持。针对该安全漏洞,从文件分离保护、开机身份认证和系统关键区域防护3个层次出发,提出了一种基于USB Key启动、动态口令手机令牌和EFI安全防护软件的三层安全加固的方案。将EFI OS Loader文件存放在USB Key中并加密,实现对文件的保护;把动态口令认证服务端置于USB Key中,两者的有机结合实现了高强度的开机身份认证;设计并开发了遵循UEFI规范的EFI应用程序型安全防护软件,实现了对系统关键区域的保护。实验结果表明,该方案的双认证与安全防护机制弥补了相关安全漏洞,增强了计算机系统启动过程的安全性。
文摘文章提出一种基于ARMll的Windows CE 6．0引导程序（Bootloader）设计与实现方法，通过分析Bootloader架构，在解析系统镜像文件和研究DownloaderImage下载函数的基础上，设计并实现一种基于Samsung6410的Windows CE6．0的Bootloader。重点阐述了其控制引导和下载镜像文件的开发过程，并给出了下载镜像函数的编程模型和算法框架。测试结果表明，该Bootloader支持通用的系统镜像文件（．bin）的下载，能够达到预期的设计目标并已应用于一款基于Samsung6410处理器的IPTV手持式测试仪系统上。
