Optimal Design of the Modular Joint Drive Train for Enhancing Cobot Load Capacity and Dynamic Performance

Automation advancements prompts the extensive integration of collaborative robot(cobot)across a range of industries.Compared to the commonly used design approach of increasing the payload-to-weight ratio of cobot to enhance load capacity,equal attention should be paid to the dynamic response characteristics of cobot during the design process to make the cobot more flexible.In this paper,a new method for designing the drive train parameters of cobot is proposed.Firstly,based on the analysis of factors influencing the load capacity and dynamic response characteristics,design criteria for both aspects are established for cobot with all optimization design criteria normalized within the design domain.Secondly,with the cobot in the horizontal pose,the motor design scheme is discretized and it takes the joint motor diameter and gearbox speed ratio as optimization design variables.Finally,all the discrete values of the optimization objectives are obtained through the enumeration method and the Pareto front is used to select the optimal solution through multi-objective optimization.Base on the cobot design method proposed in this paper,a six-axis cobot is designed and compared with the commercial cobot.The result shows that the load capacity of the designed cobot in this paper reaches 8.4 kg,surpassing the 5 kg load capacity commercial cobot which is used as a benchmark.The minimum resonance frequency of the joints is 42.70 Hz.

Effective way of alleviating poverty against poverty control: Based on the model of "Three Drives, Four Joints" in Zhen'an County

Based on the survey research of poverty controlling model of "Three Drives, Four Joints" in Zhen'an County, its forming motives, implementing mechanism, and constraint factors have been explored to testify its enlightenment and applicability, establishing a promotable, applicable, and effective poverty alleviation model. "Three Drives, Four Joints" model is linked to the poor who lacks ability of self-development. Relying on the drives from key leading companies, the capable and the rich, a community with shared interests by the poor and the subjects of the "three drives" could be formed through "Joint Production, Joint Resources, Joint Community of Stock, and Joint Operation". The linked poverty alleviation development model of "the influential and the rich bring along the poor" and "A rich household would help the others" come into being. It is found out that the model of "Three Drives, Four Joints" is in essence a poverty alleviation method focusing on the increase of the income and diversified ways of increasing the earnings. Problems of poverty alleviation carrier and joint mechanism have been solved in the poverty alleviation process. The model is innovative in activating the resource elements, helping to move the poor out of poverty. A referential, copyable, and applicable model is offered to advance the poverty alleviation in mountainous areas in China.

Research on optimal drive joints configuration of a rolling robot of closed five-bow-shaped-bar linkage

The relationship between the stability and the configuration of the driving joint was studied as a measure to improve the stability of robot.The Lagrange dynamic equation of the robot was established.According to the principle of virtual work,the least squares solution of each joint torque was obtained.The relationship between the stability of the robot and the configuration of the driving joint is obtained by the sum of the norms of the joint torque.Finally,numerical simulations verify the correctness of the theory.

Research on Angular Output Velocity of a Drive Shaft with Double Cross Universal Joints

The study object is the angular output velocity of the drive shaft which is made up of two series-wound cross universal joints. We have deduced the function relation between the angular output velocity and initiative input angle of the drive shaft with double cross universal joints that is based on the calculation formula of the angular output velocity of a single cross universal joint, and by analyzing the relation between the two input angles. By using this function relation, the constant velocity condition of the drive shaft with double cross universal joints＂ is verified. The step-by-step searching algorithm is adopted to obtain the optimal phase angle that leads to the minimum fluctuate index of the angular output velocity in the vary velocity condition. At the same time, we worked out the maximal and minimum value of the angular output velocity, and their initiative input angle. The correctness of the function of the angular output velocity and the step-by-step search algorithm are verified by an ADAMS simulation example.

基于安全接头的顶驱钻柱转矩无线测量技术研究

钻柱转矩作为反映钻具工作状态的重要参数之一,对其进行转矩测量尤为重要。本文设计了一种基于顶驱安全接头的转矩无线测量系统。以实验试件表面应变等效替代型号为AJ-H203安全接头表面应变,制作了安全接头实验试件,对安全接头和实验试件进行了有限元静力学仿真,并完成了实验试件的测量实验,实验灵敏度为9.447 V/(kN·m)。实验灵敏度与理论灵敏度偏差为0.04 V/(kN·m)。表明:实验试件替代安全接头模型进行实验是合理的,说明可以通过安全接头进行顶驱钻柱转矩的测量。

智能网联汽车超车路径规划方法

针对自动驾驶车辆超车路径规划的问题,本文提出改进的人工势场法并引入相对速度构建新的引力势场和斥力势场.建立道路边界势场规范行车区域,对障碍物的影响距离进行分段解决局部极值问题,将自动驾驶车辆动力学相关约束融入人工势场法建立超车路径行驶势场模型.选取重庆市内环快速路为试验路网原型,利用无人机以及定点摄像等数据采集方法进行实地调查,并采用MATLAB/Simulink,CarSim和PreScan进行联合仿真分析.实验结果表明:相比传统的人工势场法,在前车静止、前车匀速、前车减速这3种条件下的超车路径曲率分别降低了85.07%,62.69%和83.86%,横向加速度均小于0.13m/s^(2),改进后的路径规划算法可成功实现平稳超车,驾乘人员的舒适性上有显著提升.

液压足式机器人关节驱动系统实验台研究

为测试液压足式机器人关节驱动系统的控制性能,实现对外负载力的精确模拟并研究高性能控制策略,设计液压足式机器人关节驱动系统实验台。介绍了关节驱动系统实验台的工作原理、机械结构、液压系统及测控系统;在MATLAB/Simulink平台中建立了关节驱动系统实验台仿真模型,通过仿真分析,验证了实验台的负载模拟能力及控制性能。研究结果表明,实验台能够实现负载力加载并实现精确控制,为后续液压足式机器人关节驱动系统的研究提供平台。

基于线性自抗扰控制的柔顺伺服控制研究

对于机器人关节的主动柔顺控制的建模误差、电机系统参数变化及驱动器层高采样频率和高控制频率引入的系统扰动影响等诸多问题,提出一种基于线性自抗扰控制的柔顺控制方法。通过控制底层驱动器交轴电流实现柔顺控制,设计外力矩观测器可以实现无力传感器条件下的实时力矩估计,以达到柔性关节驱动的目的。实验对比了刚性位置控制与柔顺控制在相同阶跃输入下的位置与电磁转矩响应,验证了提出柔顺控制方法的有效性。此外,探讨了阻尼系数和刚度系数对柔顺控制的位置响应和电磁转矩响应的影响。最后在单自由度系统进行实验验证,实验结果验证了方法的有效性。

Knowledge and data jointly driven aeroengine gas path performance assessment method

Aeroengines,as the sole power source for aircraft,play a vital role in ensuring flight safety.The gas path,which represents the fundamental pathway for airflow within an aeroengine,directly impacts the aeroengine's performance,fuel efficiency,and safety.Therefore,timely and accurate evaluation of gas path performance is of paramount importance.This paper proposes a knowledge and data jointly driven aeroengine gas path performance assessment method,combining Fingerprint and gas path parameter deviation values.Firstly,Fingerprint is used to correct gas path parameter deviation values,eliminating parameter shifts caused by non-component performance degradation.Secondly,coarse errors are removed using the Romanovsky criterion for short-term data divided by an equal-length overlapping sliding window.Thirdly,an Ensemble Empirical Mode Decomposition and Non-Local Means(EEMD-NLM)filtering method is designed to“clean”data noise,completing the preprocessing for gas path parameter deviation values.Afterward,based on the characteristics of gas path parameter deviation values,a Dynamic Temporary Blended Network(DTBN)model is built to extract its temporal features,cascaded with Multi-Layer Perceptron(MLP),and combined with Fingerprint to construct a Dynamic Temporary Blended AutoEncoder(DTB-AutoEncoder).Eventually,by training this improved autoencoder,the aeroengine gas path multi-component performance assessment model is formed,which can sufficiently decouple the nonlinear mapping relationship between aeroengine gas path multi-component performance degradation and gas path parameter deviation values,thereby achieving the performance assessment of engine gas path components.Through practical application cases,the effectiveness of this model in assessing the aeroengine gas path multi-component performance is verified.

某型船用大功率液控离合器传动系统联合仿真研究

进行了有关船用大功率液压驱动齿式离合器运动学及接触动力学的Adams和AMESim联合仿真流程研究,并进行了联合仿真交互操作界面开发,在给定参数下,能够输出可视化的计算结果。仿真分析结果表明,齿式离合器轴向接合过程的动态特性与冲击载荷受到主动端扭转刚度与轮齿端面结构的影响;减压阀最大开口压力为2.5 MPa,该压力下的最大推力为1.884×10^(5) N;在内外圈发生碰撞时,油压会急速上升,如果减压阀的流量不足,则进油油路会泄漏。经过多次联合仿真发现,进口压力在0.008~0.01 MPa就能实现在4 s左右完成离合器的接合脱开过程。

从接点到融合:治理相对贫困与实现共同富裕——基于S市T区的经验观察

中国共产党领导全体人民为实现共同富裕开展了广泛深入的试点探寻和系列探索,展现了以治理驱动共同富裕的可行之法。但广大农村相对贫困地区面临的上下层级组织间张力不足、资源统筹和贯彻执行效力不足、个体驱动和参与建设动力不足等问题影响共同富裕进程。文本基于S市T区通过治贫致富的实践探索有效建构“政党组织—市场利益—社会合力”的三维结构,打通“接点驱动—融合治理—共同富裕”的运行机制,形成“以治理助力减贫,以治理驱动共富”的相对贫困地区发展经验,呈现三条关键启示:第一,结构性的“组织接点”融合是共富为民的前提条件,优化了市场经济环境;第二,要素性的“利益接点”融合是共富利民的内在机理,激活了灵活多样的项目建设;第三,功能性的“社会接点”融合是共富惠民的现实方向,为产业创新和城市转型贡献了社会力量。

欠驱动蛇形机器人轨迹跟踪算法

蛇形机器人由于其狭长的机械臂和超冗余自由度,在复杂极端环境中具有优越的灵活性。本文在欠驱动蛇形臂机器人的结构基础上,提出了基于等效杆长和等效虚拟关节的两种轨迹跟踪算法,实现蛇形臂机器人对目标曲线的跟踪,满足蛇形臂机器人的运动控制需求。最后,设计了臂长1075 mm包含7关节单元的蛇形机器人样机,并进行了轨迹跟踪实验,结果表明蛇形机器人可轻松穿过直径90 mm以上的狭小管道。运动过程平稳、无振动,验证了轨迹控制算法的正确性和结构设计的合理性。

正流量液压挖掘机多路阀阀口压力损失研究

挖掘机液压系统存在管道损失、溢流损失、节流损失及泄漏损失等问题,导致挖掘机作业过程中功率损失较大,能量利用率不高。为提高挖掘机液压系统功率利用率,以正流量挖掘机为研究对象,通过建立机电液联合仿真平台,针对多路阀压力损失较大的问题,提出改变主阀异形阀口区域过流面积的方法,以降低局部压力损失,提高液压系统的功率利用率。以铲斗联为例,改变铲斗主阀进出油口、合流阀口的过流面积及其之间的匹配,将铲斗动作的驱动效率提高了4%,降低了液压系统的功率损失,提高了液压系统的节能性能。

变长度柔性机械臂的双柔性伺服驱动系统振动抑制策略

变长度的柔性机械臂在旋转运动过程中由于受到环境扰动以及自身柔性的影响导致了伺服驱动系统输出转速的波动现象,这会加剧柔性机械臂的振动,严重影响了柔性机械臂的运动精度.基于此,设计了一种基于干扰观测器的PI控制策略来抑制伺服驱动系统转速的波动.首先使用拉格朗日原理建立了双柔性伺服驱动系统的动力学模型并分析了双柔性伺服驱动系统的传动特性;其次将基于干扰观测器的PI控制策略应用于双柔性伺服驱动系统的速度环中,并通过鲁棒稳定性分析设计干扰观测器中的低通滤波器参数;最后开展了数值仿真分析和控制实验.实验结果验证了提出的控制策略能够有效减少变长度柔性机械臂的转速波动,提高伺服驱动系统的运动精度.

粘接方式方法设计与粘接过程控制管理研究

介绍了在粘接设计过程中需要考虑的重要因素和遵循的设计原则。粘接设计前,需要考虑粘接影响因素分析、主要承受载荷的分析、基本设计规则和粘接接头承载能力分析等方面。同时从人、机、料、法、环五个维度介绍了粘接的过程控制原则,即必须根据产品特点、功能要求和发展趋势来设计;必须考虑到强度、耐久性、可维护性和经济性等方面的因素;需要选择合适的设计流程和方法来提高设计的效率和质量;还需要根据工程实际情况进行不断的调整和优化。

含内外螺纹管接头注射模设计

针对管接头同时有内外螺纹的结构,设计了1模2腔的模具,成型塑件的外螺纹及外圆柱面设计了斜导柱+弹簧+滑块的脱模机构,为了实现塑件内螺纹结构的自动脱模,设计了液压缸+齿轮齿条+齿轮传动+螺纹螺母的脱膜机构,在开模前通过液压缸活塞杆驱动该机构运动,使内螺纹型芯一边旋转一边上升完成脱模。经实际生产验证:模具动作稳定可靠,成型的塑件质量符合要求。

少先队社会化工作的动力机制研究——基于扎根理论的分析

新时代少先队工作的外部环境和参与主体已发生了新变化,少先队组织应主动适应社会,创造与中国式现代化发展相适应的工作模式,构建新时代少先队社会化工作体系。因此,本文运用扎根理论的质性研究方法探究新时代少先队社会化工作的动力机制。研究发现,参与主体的组织利益驱动、个体情感驱动构成了少先队社会化工作的内在驱动力,资源条件、文化氛围和政策环境形成了少先队社会化工作的外部驱动力。

肩部康复外骨骼单关节摩擦建模及补偿方法研究

针对肩部康复外骨骼关节转动时摩擦力大、反向驱动困难的问题,搭建了一个单关节实验平台,用于模拟肩部单关节的运动。为了较好反映运动中的摩擦力,采用Stribeck摩擦模型对单关节摩擦力进行建模,并通过最小二乘法拟合模型的未知参数,此外结合位置差和电流差的正负号确定摩擦力的方向。实验结果表明,采用Stribeck摩擦模型对摩擦力进行建模后,反向驱动力矩均值至少减少了80%,从而有效解决了肩部康复外骨骼单关节中阻力大、反向驱动困难的问题。

驱动桥主减速器壳体渗油问题分析及解决

针对某驱动桥主减速器壳体在承载系耐久试验中出现的接合面渗油问题,基于有限元分析方法,对主减速器壳体密封性能进行分析,确定了接合面错移量大导致密封胶剪断为渗油现象的主要原因,并在工装已投无法大范围改动的前提下,从减小接合面错移量和防止密封胶剪断两个方向的对策出发寻找解决方案。改进后的方案经过试验验证,主减速器接合面未发生渗油现象。所建立的解决思路对预防和解决主减速器壳体渗油具有一定的工程应用价值。

基于多岛遗传算法的电动拖拉机分布式驱动系统优化设计与试验

针对分布式驱动电动拖拉机(Distributed drive electric tractor, DDET)牵引效率低、系统能量损耗大的问题,提出了一种基于多岛遗传算法(Multi-island genetic algorithm, MIGA)的分布式驱动系统参数优化设计与验证方法。根据犁耕作业工况,建立了拖拉机分布式驱动系统7自由度耦合动力学模型以及轮胎-土壤交互模型,完成了驱动系统关键部件参数设计和匹配选型。提出基于MIGA的前后轮边传动比参数优化策略,将轮边传动比作为决策变量,驱动系统能量损失最小为优化目标,驱动电机功率和转速为约束条件。搭建Matlab/Simulink-NI PXI联合仿真平台验证了参数优化策略的正确性和实时可执行性。结果表明,基于MIGA参数优化后的分布式驱动系统各方面性能得到了有效提升。犁耕循环工况下,拖拉机平均牵引力为10 610 N,最大牵引功率为31.25 kW;平均效率提升了0.38%,驱动电机能耗降低了7.53%。本研究可为分布式驱动电动拖拉机优化设计和系统控制提供理论基础和验证方法。