基于惯性和视觉复合导航的自动导引小车研究与设计

自动导引小车(AGV)作为智能制造的重要物料搬运设备,其导航精度及路径柔性配置性能制约了其在智能制造领域的应用范围。针对这一问题,提出了基于惯性和视觉的AGV复合导航方法,利用两种导航技术的互补优势,实现高精度导航定位,提高了AGV对工作环境的适应能力和可靠性。在此基础上,利用二维码标签构建了AGV工作栅格地图,实现了AGV行驶路径的柔性配置。测试表明复合导航方法具有纵向5mm、侧向10mm、方向偏差1°的导航定位精度。

PROPER CONDITIONS OF MESHING FOR Hy-Vo SILENT CHAIN AND SPROCKET

Proper meshing of Hy-Vo silent chain and sprocket is important for realizing the transmission of the silent chain with more efficiency and less noise. Based on the study of the meshing theory of the Hy-Vo silent chain with the sprocket and the roll cutting machining principle of the sprocket with the hob, the proper conditions of the meshing for the Hy-Vo silent chain and the sprocket are put forward with the variable pitch characteristic of the Hy-Vo silent chain taken into consideration, and the proper meshing design method on the condition that the value of the link tooth pressure angle is unequal to the value of the sprocket tooth pressure angle is studied. Experiments show that this new design method is feasible. In addition, the design of the pitch, the sprocket tooth pressure angle and the fillet radius of the sprocket addendum circle are studied. It is crucial for guiding the design of the hob which cuts the Hy-Vo silent chain sprocket.

Design and Analysis of the Gemini Chain System in Dual Clutch Transmission of Automobile

Chain drive system is widely used in the conditions of high-speed, overload, variable speed and load, Many studies are focused on the meshing theory and wear characteristics of chain drive system, but system design, analysis, and noise characteristics of the chain drive system are weak. System design and noise characteristic are studied for a new type Gemini chain of dual-clutch automatic transmission. Based on the meshing theory of silent chain, the design parameters of the Gemini chain system are calculated and the mathematical models and dynamic analysis models of the Gemini chain system are established. Dynamic characteristics of the Gemini chain system is simulated and the contact force of plate and pin, plate and sprockets, the chain tension forces, the transmission error and the stress of plates and pins are analyzed. According to the simulation results of the Gemini chain system, the noise experiment about system is carried out. The noise values are tested at different speed and load and spectral characteristics are analyzed. The results of simulation and experimental show that the contact forces of plate and pin, plate and sprockets are smaller than the allowable stress values, the chain tension force is less than ultimate tension and transmission error is limited in 1.2%. The noise values can meet the requirements of industrial design, and it is proved that the design and analysis method of the Gemini chain system is scientific and feasible. The design and test system is built from analysis to test of Gemini chain system. This research presented will provide a corresponding theoretical guidance for the design and dynamic characteristics and noise characteristics of chain drive system.

EXPERIMENTAL STUDY ON HIGH-SPEED CHARACTERISTICS OF AUTOMOTIVE ENGINE OIL-PUMP CHAIN

The high-speed multi-cycle impact and speed, load fluctuant characteristics of a kind of narrow-width automotive engine oil-pump chain 06BN-1 are studied through engine assembly and road-drive tests to satisfy the light-weight demand of engine. The worn surface morphologies of rubbing area between pin, bush and roller are also analyzed based on scanning electron microscope. The results show that the main wear mechanism of automotive engine oil-pump chain is fatigue wear, and it＇s failure mechanism is the forming, extending and flaking of cracks on top layer of pin and bush. Pin and bush both occurred cycle-soften phenomenon, and roller occurred cycle-harden. Fretting wear is one of the most important ＂fall to pieces＂ failure causes of automotive chain. Ensuring sufficient strength and plasticity of roller, as well as adopting suitable shaping technology are the effective methods to increase its resistance to multi-cycle impact.

基于二次变异的齿形链内侧齿廓优化设计

提出齿形链当量链板的概念,分析了内-外复合啮合齿形链与渐开线链轮的啮合关系;指出与链轮渐开线齿廓啮合的链板内侧齿廓的正确形式,提出了一种基于二次变异的齿形链链板内侧齿廓优化设计方法;建立齿形链传动系统的多体动力学模型,对比分析了基于不同设计方法的齿形链传动系统。仿真结果表明,基于二次变异的内-外复合啮合齿形链内侧齿廓优化设计,可以显著减小齿形链传动系统的多边形效应以及啮合冲击。

基于模糊理论的滚动轴承质量评估

基于模糊理论,提出了一种评价滚动轴承质量的模糊综合评判法。首先,分析影响滚动轴承质量的因素,介绍质量影响因素权重集的确定方法;然后,建立轴承质量的模糊综合评判模型;最后,在乏信息条件下,以某型号圆锥滚子轴承质量评估为例对模型进行了验证。结果表明,利用该模型来评价轴承的质量是有效可行的。

基于啮合变异的Hy-Vo齿形链变位系数新算法

基于精准的数学建模,分别构建了Hy-Vo齿形链链板-链轮啮合模型以及滚刀-链轮啮合模型,通过构造辅助链板,提出了一种基于啮合变异的Hy-Vo齿形链渐开线链轮变位系数的新算法。基于实例,计算了不同算法下的变位系数。基于链轮的范成法模拟加工技术,得到了不同算法下的实际加工链轮。通过测量不同半径下的齿宽,分析了不同算法下的实际齿形与设计齿形的齿形偏差。基于多体动力学仿真,分析了基于不同变位系数算法下的Hy-Vo齿形链传动系统的啮合特性。结果证明,这种Hy-Vo齿形链变位系数新算法可以有效降低Hy-Vo齿形链传动系统实际性能与理想性能之间的误差,不仅计算结果更加精准,并且适用于任何滚刀齿形角与链轮压力角变异组合。

护生人文关怀品质现状与影响因素分析

目的调查河北省护生人文关怀品质现状并分析其影响因素。方法以本研究编写的护生人文关怀品质测评量表为研究工具,对河北省11所本、专科医学院校的2 693名护生进行问卷调查并分析结果。使用SPSS 21.0统计软件进行分析。计量资料采用(均数±标准差)表示,运用单因素方差分析和独立样本t检验进行对比研究,采用多元线性回归方法分析影响因素。结果研制量表总Cronbach’s α系数为0.966,各维度的Cronbach’s α系数为0.780~0.959。河北省护生人文关怀品质总得分为(119.70±15.35),总体得分率为85.50%,其中学历、年级、参加志愿者活动、性格、周围人关心程度、家庭氛围及授课教师是否提到人文关怀等的对比结果差异有统计学意义(P<0.05)。结论河北省护生人文关怀品质处于良好水平,高校可根据现状和影响因素做针对性的教育,为护生营造良好的人文课堂氛围,鼓励护生积极参加人文实践,提高护生人文关怀品质。