燃气动力弹跳机器人的设计与试验研究

以可燃混合气体为动力源,设计了一种燃气动力的弹跳机器人,包括弹跳驱动器和轮式运动机构。弹跳驱动器采用双活塞燃烧室结构及磁力锁紧机构,有效减小驱动器体积,有利于驱动器复位和废气排除。轮式运动机构包括车身和蜂窝车轮,车身作为驱动器载体,蜂窝车轮用于机器人落地缓冲。对车轮的径向、周向和切变模量进行等效计算,采用铁木辛柯梁理论对车轮进行静力分析,计算结果与试验数据吻合;利用LS-DYNA对车轮落地碰撞进行仿真,分析了落地冲击能量消耗。对机器人的弹跳运动进行规划,弹跳越障试验表明机器人可直接越过或跃上障碍物,验证了机器人的弹跳运动能力。该弹跳机器人的研究为提高地面移动机器人的未知复杂地形适应能力提供了一种可行的技术方案。     

Assessment of Al2O3 and superabrasive wheels in nickel-based alloy grinding

This paper presents experimental research on nickel-based alloy grinding using superabrasive wheels and Al₂O₃ wheels. Through on-line monitoring and off-line inspection, grinding performance and cost are studied based on statistical analysis. By using multi-objective optimization, the models of performance and cost assessment are built to evaluate the grinding performance and cost under different grinding conditions. In this way, the grinding performance and cost of different wheels can be quantitatively and qualitatively compared. With a comprehensive performance-cost analysis, the performance index of diamond wheels have been testified to be considerably higher than that of Al₂O₃ wheels even though their purchase cost is much higher than that of Al₂O₃ wheels.     

机车底架焊接翻转装置

为使机车底架上的对接焊缝处在平焊的位置进行焊接,设计了能将底架夹持进行360°翻转的机车底架焊接翻转装置.机车底架焊接翻转装置采用摩擦轮传动,将机车底架夹持在两组转轮中.两组转轮之间的距离可调节,可满足不同车型底架的翻转.翻转装置以转轮为中心翻转至任意角度并定位,保证了机车底架上对接焊缝的质量.     

乘用车钢制车轮发展方向

通过对国外车轮市场的分析,综述了国内乘用车钢制车轮发展的趋势,介绍了乘用车钢制车轮在新材料、新结构、新工艺等方面的发展方向。     

Effect of manufacturing and assembly defects on two-stage gear systems vibration

The modeling of the dynamic behavior of a two-stage gear system is made for a general configuration of wheels location. The excitation is induced by the periodic variation of the mesh stiffness. This case describes the real working of the gearings. The variation of the mesh phasing is related to the number of teeth and also to the wheels location. We developed a plane model of a two-stage gear system. The modal analysis of the system was then treated. The calculation of the dynamic response was done by a step-by-step time integration method (Newmark algorithm). Three cases of wheels location are treated. The solutions are presented both in the frequency domain and in the time domain. Three types of geometric defects of the toothed wheels are introduced in the model: defect of eccentricity, profile error and assembly defect. An analysis of the effects of these defects on the gear system dynamic behavior is then treated.     

被动行星爬楼移动平台机构设计及分析

提出一种用于爬楼越障的移动平台,对移动平台的具体结构及爬楼越障能力进行分析。移动平台由4组相同行星轮机构组成。平地行走时,移动平台行星机构在重力作用下平顺行走;爬楼时,行星机构被动抬起从而实现爬楼功能。通过简化力学模型分析移动平台车轮半径与垂直越障高度之间的关系,并用动力学仿真软件Adams对理论分析结果进行对比分析,验证分析结果。通过爬楼实验实际检验了其爬楼能力。     

有限元分析在精量播种机限深轮优化设计中的应用

限深轮是精量播种机的重要部件之一,限深轮的工作情况直接影响精量播种机的播种深度。由于原有限深轮在工作中会出现破损现象,因此利用有限元分析对已有结构进行优化设计。     

Contribution to the geometry of elliptic gears

It is shown that the motion of elliptic wheels, usually derived from the antiparallelogram, can be constrained by a crossed transmission belt which is wound around two equal elliptic disks, confocal with the rolling ellipses. By considering the relative paths of belt points, one arrives at a simple gearing system for wheels of this kind which is the natural generalization of the usual involute system for circular wheels.     

轮式移动机器人电机驱动系统的研究与开发

以嵌入式运动控制体系为基础,以移动机器人为研究对象,结合三轮结构轮式移动机器人,对二轮差速驱动转向自主移动机器人运动学和动力学空间模型进行了分析和计算,研究和设计了自主移动机器人电机驱动系统,开发了一套二轮差速驱动转向移动机器人电机驱动系统,完成了系统各部件的整体装配和调试。试验结果表明,该设计方案可行、系统运行稳定可靠、成本低廉、所用元件易于购置,具有较好的实用的价值和应用前景。     

Die ermittlung selbstanpressungsfähiger zwischenräder-anordnungen für Reibrädergetriebe mit hilfe von graphen

Friction drives with intermediate wheels are in many ways advantageous compared with those without. Intermediate wheels can generate the correct pressure-force relationship automatically. However, a designer must know all the ways in which forces can act upon such a wheel. In this paper, these ways are described for amorphous wheels. Graphs are then formed, in which vertices represent the loci of the forces acting on the wheels, and which yield the same vertex-induced permutation group as do the loci of the wheels. In any of these graphs, one can find all configurations of two-colored vertices not mappable onto each other. The technical interpretations of the vertex-colored graphs can then easily be followed.     

Force modeling and machining characteristics of the intermittent grinding wheels

In the surface grinding operations, the grinding fluid cannot be supplied sufficiently in the cutting zone. Temperature generated in the cutting zone increases rapidly and causes thermal damage such as burning on the surface of a workpiece. To reduce thermal damage, the intermittent grinding wheels, which have an excellent cooling effect, have been applied. This paper describes machining characteristics by using intermittent grinding wheels. The grinding force of the intermittent wheels has been simulated by the SIMULAB, which is a program for simulating dynamic systems. Using the intermittent grinding wheels, the characteristics of grinding force, temperature, surface roughness, and geometric error have been evaluated experimently.     

辊轮的失效分析

本文介绍了轧管机上辊轮的失效分析过程。分析了辊轮开裂和磨损的原因，并提出了提高辊轮寿命的措施。     

[轮轨磨耗及预测]弹性车轮作用下低地板有轨电车轮轨磨耗研究

为研究使用弹性车轮的车辆踏面以及运行弹性车轮的钢轨磨耗情况,基于Archard磨耗模型建立了轮轨磨耗预测模型,对不同轨道不平顺条件、不同曲线半径条件下的车轮踏面以及钢轨磨耗情况进行了分析。对比分析弹性车轮和刚性车轮,结果表明：在线路较差的情况下,弹性车轮具有更好的降磨效果;弹性车轮在曲线半径较小的线路上对磨耗的降低效果较小,随着曲线半径的增大,弹性车轮的降磨效果明显;运行弹性车轮时比运行刚性车轮时钢轨的最大累积磨耗量减小了33%;弹性车轮对曲线钢轨磨耗有一定的降低作用。     

电动固定平台搬运车四轮转向系统的分析与设计

确定了电动固定平台搬运车四轮转向系统的总体结构布置,基于两套交叉式双梯形转向机构的运动分析和四轮转向瞬时转动条件的分析,建立了前后转向轮之间的转角关系和机构优化设计模型,运用MATLAB优化工具箱获得了具有应用价值的设计结果。     

氧化铝砂轮地貌的量化评价及数学建模

砂轮地貌特征是指砂轮表面磨粒密度、磨粒切削刃和磨粒出刃高度分布等情况。准确测量和量化评价砂轮地貌不仅有助于加深对磨削机理的认识,而且是磨削过程优化、磨削过程建模与仿真不可缺少的前提条件。采用白光干涉仪对氧化铝砂轮地貌进行了测量;用伯明翰三维表面粗糙度特征参数量化砂轮地貌特征,评价不同粒度号氧化铝砂轮的磨粒密度、磨粒形状和磨粒锋利程度;根据磨粒出刃高度测量结果,利用统计方法建立氧化铝砂轮表面磨粒出刃高度分布的数学模型。结果表明,氧化铝砂轮表面磨刃形状近似为尖端带有圆球半径的圆锥形状,随着砂轮粒度号数的增加,磨刃的圆头半径减小;在同一砂轮修整工艺条件下,磨刃的顶锥角相差不大;氧化铝砂轮表面磨粒出刃高度符合正态分布规律。     

基于摩擦轮的自动推进系统的设计

介绍了一种利用摩擦轮作为传动部件来推进细径线状传感器的自动推进系统,传感器被夹持在两摩擦轮凹槽之间,依靠摩擦轮和传感器表面之间的摩擦力,利用摩擦和挤压的方式介入光纤光栅传感器。通过手柄上的弹簧调整两摩擦轮之间的间隙,还可以灵活改变介入力大小。在介绍了相应的安装了光电码盘的推进机构和工作原理之后给出了系统的电路设计和软件设计．并给出了推进实验结果。该自动推进系统具有结构简单、实现容易等特点,可以满足智能化渐进式内窥镜形状感知和重建的要求。     

基于控制的自由摆激光追踪系统

分析了自由摆激光笔控制系统设计的要点与难点,建立了激光笔转角与自由摆转角之间的数学关系。利用单片机根据一定的控制方法与策略,采用步进电机控制位于摆杆末端与激光笔固连的平板转动,使得自由摆在任意摆动过程中激光笔光斑始终能够瞄准照射在靶纸的中心。最后在该自动控制系统的基础上提出了两种改进方案。拓宽其应用范围,并且对其未来的发展方向做出了展望。     

60t履带起重机四轮一带结构有限元分析

阐述了60t履带起重机中四轮一带结构的组成和受力特点,对结构进行了有限元计算与分析,适应了履带起重机发展的需求,可以更好地指导实际生产。     

垂直轴风轮阻力型支撑杆研究

为了研究阻力型支撑杆对垂直轴风轮自启动性能和风能利用率的影响,分析了阻力型支撑杆的气动特性,获得了顺风区和逆风区作用在支撑杆上的相对风速分布。在此基础上,理论对比了圆形、V形外凸圆和V形内凹圆三种截面支撑杆各自旋转一周的平均输出转矩,分析显示,V形内凹圆截面支撑杆组成的风轮具有较好的自启动能力和稍高的风能利用率。为进一步验证理论计算结果,通过数值模拟计算了以上三种截面支撑杆各自在不同转速下的平均输出转矩。仿真结果表明：与传统的圆形截面支撑杆相比,V形内凹圆截面支撑杆能改善垂直轴风轮的自启动能力,可使风能利用率提高3.44%,这与理论分析结果吻合较好。