基于RRT算法的自由飞行空间机器人避碰运动规划

自由飞行空间机器人在微重力环境下的非完整性运动学特性是其运动规划问题的特殊难点.为此,针对空间机器人的非完整特性,提出了一个基于快速随机扩展树(RRT)算法的避碰运动规划算法.经过实验表明,该算法可以有效地求解自由飞行空间机器人的避碰运动规划问题.     

一种南方马铃薯分级装置的力学分析

运用马铃薯物理形态分级原理,研制出一种动定辊杆组合的马铃薯分级机,分析了马铃薯在该机具分级过程中的运动及动力学特性。同时,进行初步试验,研究该设备的运行速度与分级效果的关系,为样机优化设计提供试验基础。     

液压机械无级变速传动系统计算与分析

液压机械无级变速传动可以通过电控系统实现自动换挡。本文以小松WA380-3液压机械无级变速系统为例,介绍了它的组成和工作原理,对其进行了运动学分析,并阐述了在大功率拖拉机上的应用的可行性。     

栅条式水田行间除草装置运动学分析与试验研究

为解决化学药剂控制水田杂草所带来的环境污染及杂草抗药性增强等危害,设计了一种栅条式水田行间除草装置。同时,对其工作原理进行了阐述,通过运动学分析,推导了栅条的运动轨迹方程,并在试验台上进行试验研究。试验结果表明,该装置可一次性完成对杂草的压、翻、埋等作业,且在栅条个数为10个、栅条宽度为30mm、除草深度为50mm时,除草效果最佳,除草率可达81%,满足水田作业除草性能的要求。     

Effects of Shortening Breakover at the Toe on Gait Kinematics at the Walk and Trot

Point of breakover, defined as the portion of the hoof last in contact with the ground during the terminal stance phase of a limb, can be influenced by many factors including craniocaudal placement of the shoe. Shortening the point of breakover has been suggested to decrease strain on the deep digital flexor tendon and navicular bone as well as to improve the alignment of the second and third phalanx. The current experiment involved eight sound horses fitted with aluminum plates adhered to their front hooves, which were drilled and tapped to allow additional aluminum plates of various lengths to be attached (the longest plate was placed flush with the toe, while the shortest plate was moved 3.81 cm caudal to the toe). Horses were recorded on video while at the walk and trot over a distance of 70 meters for six repetitions to determine differences in gait kinematics. Results of this study show significant changes in stride kinematics caused by shortening the point of breakover. Retraction of the forelimbs was greatest when breakover was moved 1.27 cm back from the toe (P < .05), and minimum height of the fetlock at the trot was higher on all treatments where the breakover point was moved caudally (P < .05). Some improvements in gait quality were observed when breakover was shortened, although extreme caudal placement of the shoe (negative placement in relation to P3) resulted in a decrease in gait quality as seen by decreased retraction of the forelimb (P < .05) coupled with hoof height occurring earlier in the stride (P < .05).     

Robot Manipulator Lettering Technology and Motion

Lettering robot manipulator is a kind of teaching and science popularization device which is fit for schools and science museums and so on. The basic construction, parameter and control system are introduced. The homogeneous transformation equation of manipulator is created according to the Denavit-Hartenberg method, and the kinematics solution and inverse kinematics solution are analyzed. The present state of vector font handling in CAD/CAM application is summarized. Because it is difficult to analyze directly the format of TTF font file and to get the outline of a certain letter, we call the windows API function GetGlyphOutline to read the data of TTF vector font in windows system. On the dot array mongline font we have vectorize it with VC++.Through the wectorised data and kinematics equation,the track programming and control and so on can be realized.     

一类6-SPS相似平台并联机构正运动学的简明解

6-SPS相似 Stewart平台是一种动、静平台均为平面六边形 ,且彼此相似的并联机构。并联机构正运动学是一个位置和姿态耦合的复杂非线性问题 ,难以求得解析解。通过引入四元数来表示旋转变换和应用对偶空间方法对高阶多项式进行降阶处理 ,可以用一组二阶方程来表示该类并联机构的正运动学。在这组方程中 ,动平台的位置和姿态是解耦的。此外 ,在方程组求解过程中 ,能避免产生伪复根。最后通过求根公式直接得到机构动平台位姿的 8个解析解     

加强白蚁防治管理,营造社区和谐

阐述白蚁基本理论,分析和探讨白蚁的危害,以及白蚁防治中存在的主要问题,并针对问题提出具体的建议与对策。     

4LB-0.7型半喂入联合收割机的振动控制与研究

4LB-0.7型半喂入水稻联合收割机具有体积小、重量轻、结构简单、稳定性高等优点,特别适合山区小田块水稻收割。该机采用的滑块式切割机构在作业时会产生较大的惯性力,从而引起收割机不断振动,甚至导致联合收割机不能正常工作,必须在曲柄上增加一定质量的配重以减少振动。通过对该机的切割机构进行动力学分析和研究,用三维直角坐标确定机构中各构件的位置,并建立曲柄、滑块、割刀的运动学模型,利用程序计算得到最优位置和最合理的配重质量,这样就可以解决振动问题。