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体育运动中统一的人体多刚体模型及动力学分析方法 总被引:5,自引:0,他引:5
本文介绍了人体的多种多刚体模型及在体育中的应用,提出了统一的人体多刚体模 型,讨论了该模型的自由度、广义坐标、人体参数等。在比较了多种动力学分析方法后,建 议采用KANE方法。 相似文献
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为了能准确地模拟人体的振动响应特性,并减少模型的复杂程度,结合分析力学和人体各部位实际状况,建立了六自由度坐姿人体动力学模型。列出了该模型的运动微分方程,并推导出人体振动响应特性的计算公式,以试验数据为依据,以动态等效质量和座位处到头部传递函数为目标,运用多目标优化方法获得了模型参数。结果显示,六自由度模型能准确的拟合人体振动响应特性曲线。将该模型与经典的集中参数模型(ISO 5982(2001)模型)和复杂生物力学模型(Tae-Hyeong Kim的模型)进行对比分析,该模型能更好地拟合实验数据,其结构简单却能相对完整、准确地反映人体动态特性,可用于人体振动响应仿真分析。 相似文献
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面向人体损伤的载货车-摩托车事故再现研究 总被引:1,自引:1,他引:0
面向人体损伤的交通事故再现主要依据事故遗留下的刹车印迹、车身及其他相关物体变形、人体损伤等多种信息。在此基础上利用数值模拟技术获得碰撞前的速度及接触位置,结合多刚体动力学和人体损伤分析等理论方法得出人体损伤部位的生物力学数值。通过上述方法对一起车-摩托车碰撞事故案例进行实际应用,详细介绍了多刚体模型的建立步骤,及碰撞的接触,计算得到数值模拟结果与法医鉴定结果吻合,从而通过使用上述方法可以为交通事故责任鉴定提供理论依据和数值参考,同时可以对法医勘验结果给出合理解释。 相似文献
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浮式风机是深远海域风力发电的关键结构,分析其在复杂海况下的动力学响应特征对保障远海风能开发具有重要意义。在初步设计和方案比选阶段,需要开发能够定量把握浮式风机动力学主要特征、且分析高效的一体化分析模型。为此,针对大型Spar式海上浮式风机,建立了多刚体动力学全耦合分析模型。基于Lagrange方程,推导了考虑桨叶转动与桨距控制的8自由度刚体运动方程。结合所建议的多刚体模型,基于Spar式浮式风机1∶50缩尺模型试验实测数据,建立了与试验物理模型相应的一体化多刚体数值模型,并进行了静力、纯风、纯浪以及风?浪联合条件下数值分析结果与试验观测结果的对比分析。采用本文建模理论,建立了OC3?Spar式浮式风机足尺结构数值分析模型,并与常用的风机结构分析软件FAST的计算结果进行了对比分析。通过与上述缩尺物理模型试验和足尺数值模型软件分析对比,验证了浮式风机多刚体动力学分析模型的有效性。 相似文献
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突破了仅对两自由度平面柔性机械臂进行研究的传统,而对多自由度空间柔性机械臂进行动力分析。用假设模态法表示臂杆柔性,并将变形量融入D-H坐标系,通过对机械臂末端的轨迹规划得到刚性运动学的逆解。运用Kane方法对多自由度的空间柔性机械臂进行动力学建模,推导出完整的系统动力学方程,采用较高精度的四阶龙格-库塔法对动力方程进行积分求解。给定一个六自由度柔性机械臂模型,并对其进行数值仿真,验证了臂杆柔性对机械臂的动力响应产生的重要影响。 相似文献
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Arikawa K Hirose S 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2007,365(1850):171-183
The performance of existing actuators, such as electric motors, is very limited, be it power-weight ratio or energy efficiency. In this paper, we discuss the method to design a practical walking machine under this severe constraint with focus on two concepts, the gravitationally decoupled actuation (GDA) and the coupled drive. The GDA decouples the driving system against the gravitational field to suppress generation of negative power and improve energy efficiency. On the other hand, the coupled drive couples the driving system to distribute the output power equally among actuators and maximize the utilization of installed actuator power. First, we depict the GDA and coupled drive in detail. Then, we present actual machines, TITAN-III and VIII, quadruped walking machines designed on the basis of the GDA, and NINJA-I and II, quadruped wall walking machines designed on the basis of the coupled drive. Finally, we discuss walking machines that travel on three-dimensional terrain (3D terrain), which includes the ground, walls and ceiling. Then, we demonstrate with computer simulation that we can selectively leverage GDA and coupled drive by walking posture control. 相似文献
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21世纪是品牌竞争的时代。一个国家拥有品牌的数量多少、质量高低、价值大小反映了一个国家的经济实力,一个企业拥有的品牌质量和价值反应了这个企业的可持续发展能力。
山西杏花村汾酒集团是全国最大的清香型白酒生产企业,但是在各白酒企业纷纷打造品牌内涵、开展强势品牌营销的今天,汾酒集团的步伐显得缓慢。因此在竞争中,汾酒集团落在了后面。 相似文献
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中国的传统快消行业竞争已经到了白热化的阶段,最低成本、差异化营销、市场集中的营销战略已经被企业用到极致,营销面临着思路的枯竭和同质化日趋严重的局面。新的营销之路在哪里?成为快消行业人士共同冥想和探究的目标。 相似文献
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Brian R. Umberger 《Journal of the Royal Society Interface》2010,7(50):1329-1340
Leg swing in human walking has historically been viewed as a passive motion with little metabolic cost. Recent estimates of leg swing costs are equivocal, covering a range from 10 to 33 per cent of the net cost of walking. There has also been a debate as to whether the periods of double-limb support during the stance phase dominate the cost of walking. Part of this uncertainty is because of our inability to measure metabolic energy consumption in individual muscles during locomotion. Therefore, the purpose of this study was to investigate the metabolic cost of walking using a modelling approach that allowed instantaneous energy consumption rates in individual muscles to be estimated over the full gait cycle. At a typical walking speed and stride rate, leg swing represented 29 per cent of the total muscular cost. During the stance phase, the double-limb and single-limb support periods accounted for 27 and 44 per cent of the total cost, respectively. Performing step-to-step transitions, which encompasses more than just the double-support periods, represented 37 per cent of the total cost of walking. Increasing stride rate at a constant speed led to greater double-limb support costs, lower swing phase costs and no change in single-limb support costs. Together, these results provide unique insight as to how metabolic energy is expended over the human gait cycle. 相似文献
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Kimura H Fukuoka Y Cohen AH 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2007,365(1850):153-170
We describe here the efforts to induce a quadruped robot to walk with medium-walking speed on irregular terrain based on biological concepts. We propose the necessary conditions for stable dynamic walking on irregular terrain in general, and we design the mechanical and the neural systems by comparing biological concepts with those necessary conditions described in physical terms. PD-controller at joints constructs the virtual spring-damper system as the viscoelasticity model of a muscle. The neural system model consists of a central pattern generator (CPG), reflexes and responses. We validate the effectiveness of the proposed neural system model control using the quadruped robots called 'Tekken1&2'. MPEG footage of experiments can be seen at http://www.kimura.is.uec.ac.jp. 相似文献