差分粒子群算法在PUMA机器人逆运动学求解中的应用     

汪院林  袁锐波  袁安华 《教育技术导刊》2020,19(4):203-207

传统逆运动学求解主要从逆运动学方程出发,基于一定的数学理论推导,不能完全实现计算机程序化,且精度与计算效率较低;为改善这一缺陷,基于机器人正向运动学方程,借助MATLAB工具,使用蒙特卡洛法仿真分析出PUMA560机器人的工作空间,任取一点末端执行器位姿作为逆运动学求解的已知位姿矩阵T,结合差分粒子群仿生智能算法作为逆运动学求解的主要理论算法。将计算出的旋转关节变量[θ1~θ6]代入正运动学方程,得出末端位姿矩阵[T];通过计算分析T与[T]相关角度误差,两矩阵所对应的位置向量与姿态向量误差精度为0.001数量级,完全满足目前机器人定位要求。基于差分粒子群理论的机器人逆运动学求解方法计算收敛速度更快,能高度实现计算机程序化,误差精度高,提高计算效率。  相似文献   

Graphonomics,automaticity and handwriting assessment     

Oliver Tucha  Lara Tucha  Klaus W. Lange 《Literacy》2008,42(3):145-155

A recent review of handwriting research in Literacy concluded that current curricula of handwriting education focus too much on writing style and neatness and neglect the aspect of handwriting automaticity. This conclusion is supported by evidence in the field of graphonomic research, where a range of experiments have been used to investigate this issue from a movement perspective. The present article offers a brief introduction to a graphonomic approach to handwriting analysis and the findings of graphonomic research about handwriting automaticity. These findings indicate that attentional control to any characteristic of the writing process (e.g. direction, lexical status, movement, style) results in an impairment of handwriting automaticity. These findings support and add a new dimension to previous conclusions.  相似文献   

Shorter Method for Computing the Coefficient of Correlation     

《The Journal of educational research》2012,105(3):216-221

ABSTRACT

Handwriting is used throughout the school day and is important to demonstrate knowledge. This research evaluated how handwriting instructional practices and intrinsic and extrinsic factors in actual classroom settings impacted learning handwriting over the course of the school year. Findings indicated that extrinsic factors (educational instructional practices, spatial constraints) and intrinsic factors (task cognitive complexity) influenced handwriting performance, but not always in the same way for writing product and process measures. In addition, stronger relationships were found between writing process measures and handwriting fluency than legibility. Even though handwriting improved over the school year, some instructional practices resulted in a widening performance gap as the school year progressed. The impact of these findings for implementing and differentiating handwriting instruction and guiding future research is discussed.  相似文献   

第十一届全运会我国优秀男子跳远运动员起跳技术的运动学分析     

巩磊 《山东教育学院学报》2012,27(1)

选取第十一届全运会男子跳远前4名运动员为研究对象,使用二维高速摄像的研究方法,采用APAS动作解析软件对跳远起跳技术进行了定量分析。通过分析发现：我国优秀跳远运动员踏跳离地瞬间垂直速度、速度损失量和腾起角与世界优秀运动员都有显著性差异。由此提出指导跳远运动员实际训练的建议。  相似文献   

优势脚与非优势脚正脚背踢球的运动学特征对比研究     

部义峰  李世明  秦玉鹏  熊安竹  韩静 《天津体育学院学报》2007,22(4):337-341

足球运动中踢球脚有优势脚与非优势脚之分,优势脚踢球主要表现为踢球力量大、出球准确,而非优势脚则与之相反。两者摆动腿摆动特征具有相似性,但运用生物力学手段对其研究发现,优势脚与非优势脚摆动腿的摆动特征存在很多差异性,主要表现在非优势脚摆动腿的蹬地不充分、股后肌群力量较弱、小腿屈曲不充分、小腿前摆时间过早、膝关节制动太早以及小腿前摆不充分等一系列差异上。因此,平时应该加强非优势脚训练,以形成正确动力定型。  相似文献   

跳板跳水跨跳步摆动肢体的运动学分析     

刘卫国  陈晓光  李欣  宋刚  刘卉 《北京体育大学学报》2009,(5)

以国家队10名优秀男子跳板跳水运动员为研究对象,在合理界定跨跳步时相的基础上,对其摆动肢体的运动特征进行分析。发现跨跳步的摆臂方式是直肘沉臂和屈肘升臂、跨跳步的摆腿是采用控膝摆髋技术来增大人体的压板力量、快升臂和高提腿有利于增大有效压板和腾空高度。同时分别得到了跨跳步自由肢体摆动与支撑腿蹬伸协调配合的具体运动学特征和控膝摆髋技术的具体运动学参数。  相似文献   

男子标枪运动员“第二支撑制动现象”的运动学特征分析   总被引：5，自引：0，他引：5  

谭建共 《西安体育学院学报》2000,17(4):32-36

借助KS— 16mm高速摄影机 ,对我国第五届大学生运动会前 8名男子标枪运动员最后用力双支撑阶段的投掷动作进行了拍摄。研究结果 :把髋理解为“第二支撑制动环节” ,有助于对该环节的重视 ,更有助于了解其在最后用力过程中产生制动所发挥的作用。“第二支撑制动现象”的出现 ,对上肢的“鞭打”动作 (投掷效果 )有着直接的影响  相似文献   

竞技健美操提臀类与分切类难度动作的运动学对比研究     

赵轩立  张晓莹  刘曦 《山东体育学院学报》2020,(1):82-88

高分值难度动作的选编是竞技健美操比赛运动员获胜的根本。作为难度组合的常用动作,提臀类与分切类难度动作在国际高水平赛事中选用甚多,两类动作技术的掌握对于运动员成套编排和训练以及难度分值的提升尤为重要。以高分值难度A207与A220为例,对提臀类与分切类难度动作进行运动学对比研究.比赛中两个难度区分度较低,容易混淆,A220较A207更具竞争力,但A220难度技术复杂,失误率较大。运用Qualisys红外光点高速运动捕捉系统,深层次剖析A220与A207每个动作阶段的运动学特征。研究结果表明:1)以背阔肌为主导的肩关节稳定性是提臀类和分切类难度动作推起腾空的基础。2)分切类难度肩关节高度高于髋关节,左右髋关节角度变化差异较提臀类难度动作更大。3)A207与A220两个动作总体用时无显著性差异,身体重心Z轴位移变化趋势无明显差异。4)腾起高度是运动员高质量完成提臀类与分切类难度动作的基本条件。  相似文献   

跆拳道后横踢四种战术动作击打速度效果特点及对运动训练的启示     

徐春杰  刘卫军  刘德皓  于海龙 《成都体育学院学报》2020,(1):114-120

目的:研究跆拳道后横踢4种战术动作的击打速度效果及对运动训练的启示。方法:以跆拳道后横踢"进攻""迎击""反击""近身"4种战术动作为研究对象,运用Motion-Analysis红外光点高速运动捕捉测试系统,研究在"空击"状态下部分关节转动幅度,人体重心位移变化,膝关节和踝关节的速度、加速度;并运用电子护具采集后横踢4种战术动作的击打力量。结果:进攻、反击战术动作在骨盆、髋关节旋转上与迎击、近身战术动作有差异(P<0.05),而在躯干、膝和踝关节旋转上没有差异(P>0.05)。进攻、迎击、近身战术动作的提膝向心加速和踝关节离心加速好于"反击"(P<0.05)。进攻、迎击、近身战术动作的提膝速度、击打速度均高于"反击"(P<0.05),击打力量也高于"反击",尤其是"进攻"(P<0.05)。"进攻"和"反击"重心移动速度高于"迎击"和"近身"(P<0.01),向心加速度也高于"迎击"和"近身",尤其是"进攻"(P<0.05),但"反击"移动方向与击打方向相反。结论:跆拳道后横踢4种战术中,"进攻"与"反击","迎击"与"近身"动作结构类似;"进攻""迎击""近身"在整个过程中各环节动作肌肉收缩用力、动量传递、击打力量方面均优于"反击",特别是"进攻"显著优于"反击"。在运动训练中,要以比赛规则为导向,了解战术运用现状,科学提高击打速度,提升击打效果策略,更新运动训练思路。  相似文献   

The influence of water depth on kinematic and spatiotemporal gait parameters during aquatic treadmill walking     

Taeyou Jung  Yumi Kim  Hyosok Lim  Konstantinos Vrongistinos 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(3):297-307

The purpose of this study was to investigate kinematic and spatiotemporal variables of aquatic treadmill walking at three different water depths. A total of 15 healthy individuals completed three two-minute walking trials at three different water depths. The aquatic treadmill walking was conducted at waist-depth, chest-depth and neck-depth, while a customised 3-D underwater motion analysis system captured their walking. Each participant’s self-selected walking speed at the waist level was used as a reference speed, which was applied to the remaining two test conditions. A repeated measures ANOVA showed statistically significant differences among the three walking conditions in stride length, cadence, peak hip extension, hip range of motion (ROM), peak ankle plantar flexion and ankle ROM (All p values < 0.05). The participants walked with increased stride length and decreased cadence during neck level as compared to waist and chest level. They also showed increased ankle ROM and decreased hip ROM as the water depth rose from waist and chest to the neck level. However, our study found no significant difference between waist and chest level water in all variables. Hydrodynamics, such as buoyancy and drag force, in response to changes in water depths, can affect gait patterns during aquatic treadmill walking.  相似文献