关键词： Large-scale interval parameters   Dynamic systems   Screening method   High-order polynomials surrogate model   Sampling method  

摘要： This paper proposes a non-intrusive computational method for mechanical dynamic systems involving a large-scale of interval uncertain parameters, aiming to reduce the computational costs and improve accuracy in determining bounds of system response. The screening method is firstly used to reduce the scale of active uncertain parameters. The sequential high-order polynomials surrogate models are then used to approximate the dynamic system's response at each time step. To reduce the sampling cost of constructing surrogate model, the interaction effect among uncertain parameters is gradually added to the surrogate model by sequentially incorporating samples from a candidate set, which is composed of vertices and inner grid points. Finally, the points that may produce the bounds of the system response at each time step are searched using the surrogate models. The optimization algorithm is used to locate extreme points, which contribute to determining the inner points producing system response bounds. Additionally, all vertices are also checked using the surrogate models. A vehicle nonlinear dynamic model with 72 uncertain parameters is presented to demonstrate the accuracy and efficiency of the proposed uncertain computational method.

关键词： Space stations  

摘要： The manipulator mechanism of space station with clearance was taken as the research object, and the influence of motion pair wear on the motion output accuracy of the mechanism was analyzed. Firstly, the dynamic modeling of the mechanism was carried out by combining the Lankarani-Nikravesh contact impact force model and the LuGre stagnation-slip friction model, and the relationship function between wear depth and puncture depth and stiffness coefficient was established. Secondly, the dynamic response characteristics of the system under different clearance conditions were explored. Finally, the simulation results were combined with the Archard model to analyze the wear of the motion pair under different conditions, reconstruct the irregular clearance surface, and solve the effect of wear on the dynamic response of the system. The results show that for the open-loop mechanism, the closer the clearance position is to the end effector, the greater the influence on the end effector is. The wear of the kinematic pair connected to the spacecraft body is more serious. Under the irregular clearance, the time of velocity and acceleration fluctuation lags behind that of the regular clearance. © 2025 Chinese Vibration Engineering Society. All rights reserved.

关键词： Underwater manipulator   Pulsating flow   Hydrodynamic performance   Vortex shedding   Flow interference  

摘要： Pulsating flow is a common condition for under water manipulators in Bohai *** study aimed to investigate the effects of pulsation frequency and amplitude on the hydrodynamic characteristics of an underwater manipulator with different postures using the user-defined function (UDF) method. The lift coefficient (C_(L)), drag coefficient (C_(D)), and vortex shedding of the underwater manipulator in single-and dualarm forms were obtained. Results indicated that the maximum increase in the lift and drag coefficients subjected to the pulsation parameters was 24.45%and 28%, respectively, when the fluid flowed past a single arm. Compared with the single arm, the lift and drag coefficients of the arms were higher than those of the single arm when arm 2 was located upstream. Additionally, the pulsation frequency had no obvious effect on the manipulator, but the C_(L) and C_(D) of arm 2 showed an obvious increasing trend with an increase in pulsation amplitude. Meanwhile, when arm 2 was located downstream, the C_(L) and C_(D) of arm 2 were reduced by 16.38%and 1.15%, respectively, with an increase in the pulse frequency,and the maximum increase in the lift and dragcoefficients was 33.33%and 16.78%,respectively,with increasing pulsation ***, the downstream wake morphology changed significantly, and a combined vortex phenomenon appeared. Finally, a theoretical basis for examining the hydrodynamic characteristics of marine engineering equipment was established to aid future marine resource exploitation.

关键词： 仿生机械结构   新型烟花喷射动力学   仿生学  

摘要： 基于仿生学原理,研究借鉴了自然界生物(如蜂鸟、水母等)的形态特征与运动机制,对烟花喷射系统的设计进行了优化,以提高烟花喷射效率、增强视觉效果以及提升轨迹控制精度。通过结合计算流体动力学(CFD)、非线性动力学模型,经过试验验证,研究设计了仿生烟花喷射动力学模型,得到了喷射高度提升15%、燃料效率提高20%等显著成果。从传统理论和理论创新两个方面论述了新型烟花喷射动力学基础;阐述了仿生机械结构与烟花喷射的关系,包括仿生设计在烟花喷射系统中的应用、仿生机械结构对烟花喷射性能的影响;建立与优化了基于仿生机械结构的烟花喷射动力学模型;评估了仿生烟花喷射系统的性能;简述了仿生烟花喷射技术的未来发展趋势。

关键词： 核电动力机械手   控制系统设计   视频采集  

摘要： 针对核电站机械手的作业需求提出一个综合性的控制系统设计方案,该系统以实现精确控制和高效作业为核心目标,融合先进的硬件模块与软件算法。在控制系统总体设计中,针对机械手的运动控制需求,设计下位机运动控制系统和上位机遥操作系统,实现设备的精准运动控制。硬件模块设计包括控制器、伺服系统和防辐射摄像头的设计原理和实现方法,并通过系统测试验证了设计方案的有效性和稳定性。

关键词： 机械臂   瞬态动力学分析   受力特性   ANSYS Workbench  

摘要： 通过ANSYS Workbench对ABB IRB760机械臂进行瞬态动力学分析,探究机械臂在不同载荷条件下的受力特性变化趋势。首先建立ABB IRB760机械臂的三维仿真模型,并对机械臂中复杂的连接结构进行等效和简化。其次将模型导入ANSYS Workbench,利用其有限元分析功能得到机械臂在不同载荷下的等效弹性应变、等效应力变化趋势。最后对仿真结果进行分析。

关键词： 机械动力牵拉法   下肢整体康复训练   踝关节骨折   康复  

摘要： 目的:观察踝关节骨折患者术后康复应用机械动力牵拉法联合下肢整体康复训练后的效果。方法:按照随机数字表法将我院2023年4月至2024年6月收治的71例踝关节骨折术后患者分为对照组(接受下肢整体康复训练,n=35)和研究组(接受机械动力牵拉法联合下肢整体康复训练,n=36),两组均干预8周。对比两组干预前后的踝关节功能改善情况、疼痛程度改善情况、关节活动度改善情况、步态指标改善情况。结果:研究组干预4周后、干预8周后美国矫形足踝协会踝-后足评分系统(AOFAS)评分高于对照组(P<0.05)。研究组干预4周后、干预8周后视觉疼痛模拟评分(VAS)评分低于对照组(P<0.05)。研究组干预4周后、干预8周后背伸活动度和跖屈活动度大于对照组(P<0.05)。研究组干预4周后、干预8周后步频、步速、步长大于对照组(P<0.05)。结论:机械动力牵拉法联合下肢整体康复训练可有效促进踝关节骨折患者的踝关节功能恢复,扩大踝关节活动度,减轻疼痛。

关键词： 电动农业机械   动力系统   能量管理   性能优化   仿真分析  

摘要： 针对水稻收割机电动化过程中动力系统设计以及优化问题,本文以苏州久富农业机械有限公司4LZ-2.5型收割机为研究对象,通过实地测试获取各工况下的负载特性数据,建立了基于实测数据的动力系统数学模型,采用360V电压等级设计动力电池组,优化永磁同步电机控制策略,开发了适应农+田作业的双电机协同控制系统,试验表明,优化后的动力系统在标准收割工况下,主电机效率达92%,系统续航时间超过7小时,最大爬坡度32%,满足水稻收获作业要求,研究成果已在江苏省水稻主产区推广应用,为农业机械电动化提供了实践验证的技术方案。

关键词： 农业机械   劳动力   粮食产出  

摘要： 农业机械化发展是替代劳动力减轻劳动强度的一种发展模式,机械化程度以及劳动力替代强度会直接影响到粮食的产出数量与质量。本文重点分析农业机械对劳动力的替代强度和粮食产出的影响,进一步分析利用农业机械提升粮食产出量,保证粮食产出品质的科学方法。通过本文分析可知,农业机械对劳动力替代程度的影响主要表现在提高生产效率、降低生产成本、解放劳动力三个方面。而对粮食产出的影响主要体现在保障粮食稳产增产、促进农业绿色发展、形成标准化产出流程。为充分发挥农业机械的积极作用。需要在粮食生产过程中,推广应用先进的农业机械设备、加大农机设备应用培训力度、发展农机社会化服务,达到普及应用农业机械设备,达到提升粮食产出总量和质量的效果。

关键词： 液压支架   结构优化   动力学分析   有限元   多体动力学  

摘要： 研究旨在优化液压支架的机械结构并进行动力学分析,以提高其工作性能和可靠性。采用有限元分析和多体动力学仿真相结合的方法,对液压支架进行结构优化设计。结果表明,优化后的液压支架承载能力提高15%,动态响应时间缩短20%。通过合理的结构优化和动力学分析,可显著提升液压支架的整体性能,为煤矿安全高效生产提供有力支撑。