双足交替支撑轮滑步态的实验研究

单台摄影机拍摄是研究二维平面步态运动的传统方法,将其与正交摄影法相结合,并通过参考平面和参考标记点的引入,能较好地确定额状面内关节标记点的横向坐标,对具有三维运动特征的人体“单腿支撑单腿摆动”轮滑运动步态进行定量的实验研究,所得实验结果能从仿生学角度指导双足溜冰机器人的步态设计。     

水陆两栖蛇形机器人的研制及其陆地和水下步态

针对沼泽、浅滩等复杂环境对蛇形机器人的环境适应需求,在广泛分析国内外水陆两栖蛇形机器人研究最新进展的基础上,研发一种新型水陆两栖蛇形机器人。该机器人由9个具有密封设计的万向运动单元组成,保证了样机在陆地和水中均能灵活运动。基于简化的蛇形曲线得到水陆两栖蛇形机器人的基本二维运动步态即蜿蜒运动。对两个垂直平面上,即水平面和竖直面上基本步态进行复合,由基于启发式思想的三维步态生成方法,得到包括侧向蜿蜒等运动的水陆两栖蛇形机器人的多种陆地步态和水下步态,其中S形翻滚运动和螺旋翻滚运动为蛇形机器人的两种新型步态。通过步态试验验证了水陆两栖蛇形机器人的陆地和水下运动能力。在试验过程中,对陆地和水下步态的性能做出分析,分析结果对水陆两栖蛇形机器人在陆地和水下运动的位置和姿态控制具有重要意义。     

单自由度概率翻转移动连杆机构

基于一种过约束伸缩机构,设计一种单自由度的概率翻转移动连杆机构。通过分析机构的移动原理得出该机构具有两种运动步态,即定向步态和概率步态。定向步态的机构移动有确定的方向;概率步态的机构移动有两个可能方向,此随机过程在理想条件下符合伯努利概率分布。针对机构的移动特性和移动路径,提出使其在平面内任意运动的控制方法。建立移动机构的动力学模型并进行运动仿真。仿真结果表明,通过两种步态的组合控制,可以使机构实现从指定的出发点到达任意的预期目标点的平面移动。制作一台样机,验证了该单自由度机构的移动和转向功能。     

机器鳄鱼运动的仿生步态规划方法

模仿真实动物的运动步态是仿生机器人步态规划研究的一个重点。针对一种新型仿生机器鳄鱼的步态规划问题,采用动作捕捉技术获取了真实鳄鱼的运动步态。在此基础上,利用高斯牛顿法求解出机器鳄鱼的腿部关节角度,拟合得到与真实步态轨迹相似性较好的仿生步态,并分析了机器鳄鱼在该步态下的运动稳定性。虚拟样机的运动仿真实验结果表明：机器鳄鱼能用与真实鳄鱼相似的步态,以0.3 m/s的速度向前爬行,且具备较高的稳定性。     

多维数据关联的机器人运动步态识别方法

针对机器人运动步态识别方法存在有效识别率较低等问题,提出一种基于多维数据关联的机器人运动步态识别方法.首先通过背景减除法进行图像提取,采用形态学方法去除图像中的噪声及空洞;然后使用多维数据关联提取机器人运动步态轮廓形状静态特征,将计算动作能量图(AEI)以及步态能量图(GEI)进行对比分析,获取GEI更多的动态能量信息;最后通过FEI进行Fan—Beam变换,采用核主成分分析进行空间降维,获取运动目标的频率动态特征,将两个特征进行融合实现机器人运动步态识别.实验结果表明,研究方法能够快速、准确实现机器人运动步态识别,实际应用效果好.     

地面移动Altmann连杆机构

提出Altmann连杆机构的一个新用途,将其用来作为地面移动机构,以翻跟斗步态实现沿直线的行走运动,并通过自身扭动与整体反转的步态实现转向运动。提出地面移动Altmann连杆机构的设计概念和构型方案。分析地面移动Altmann连杆机构的移动原理,包括利用奇异位形来实现机构的转向运动。规划出直行和转向两种移动步态。分析两种步态的移动轨迹,并计算两种移动步态的关键参数。研究结果表明,通过对直行和转向两种步态的切换控制,可以使Altmann地面移动连杆机构以固定的步长,从平面上一个初始点移动到另一个目标点。该地面移动连杆机构基于空间单闭链六杆机构,结构简单,刚度好,同时具有良好的折叠特性,便于存储和运输。     

四足机器人在直行和转弯下的步态规划研究

针对四足机器人的直行和转弯运动,以爬行步态为基础,分别对其进行了步态规划.提出了协调旋转步态的概念并用于原地转弯中;找出直行步态与原地转弯步态的足端轨迹公共点,通过该点实现了步态的快速迁移并用于四足机器人的弯道转弯运动中;根据对四足机器人的结构设计,建立了四足机器人的虚拟样机;提出了一种新的评价准则——角度余量准则(SA准则),对规划的步态进行稳定性评价,从而找出最优步态.搭建实验平台进行了实验,结果显示,针对直行和转弯的步态规划合理、可行.     

基于蛇类生物的仿生变体机器人运动学研究

基于仿生机械学的原理,本文提出了仿生变体机器人的物理结构,讨论了仿生变体机器人的运动机理,分析了仿生变体机器人线形运动的基本步态.并对该机器人系统进行了运动学分析,实验结果证明了这种运动步态的可行性.最后指出了这种基本运动步态的局限性和改进的方向.     

蛇形机器人伸缩运动仿生研究

对生物蛇在不同环境中的运动步态进行了观察与试验,试验发现蛇具备垂直平面内的伸缩运动功能。详尽分析了水平面内和垂直面内伸缩运动的运动机理、运动特点和它们所能适应的特殊环境。分别建立了两种伸缩运动的数学模型,并对数学模型进行了运动学分析。根据蛇的伸缩运动机理,设计了蛇形机器人的仿生机械结构。最后根据数学模型,对蛇形机器人进行了伸缩运动试验,验证了这两种运动步态的可实现性。     

仿壁虎机器人地壁过渡步态规划与运动仿真

针对传统仿壁虎机器人空间运动能力不足、空间运动步态方法的可行性问题,基于仿生学原理,设计了一种具有腰关节的每条腿具有三个自由度的四足仿壁虎机器人,对仿壁虎机器人的结构进行了正运动学和逆运动学的分析,建立了各关节角度和机身空间坐标系下各参量之间的关系,在地面与墙壁交角为90°的工况下,根据其关于纵向平面对称的结构特点提出了一种对称式地壁过渡步态方法。在Matlab软件上对该步态方法的可控性进行了评价,利用各关节角度与各参量之间的函数关系编程得到了地壁过渡过程中各关节角度、角速度曲线,并在Inventor环境下进行了运动学仿真实验。研究结果表明,各关节角度、角速度均在允许范围内,且角度函数一次连续,验证了结构的合理性和步态的可行性。     

The comparison of joint kinematic error using the absolute and relative coordinate systems for human gait

Minimizing artifacts from skin movement is vital for acquiring more accurate kinematic data in human movement analysis. There are several stages that cause skin movement artifacts and these stages depend on the selection of the reference system, the error reduction method and the coordinate system in clinical gait analysis. Due to residual errors, which are applied to the Euler and Bryant angle methods in each stage, significant cumulative errors are generated in the motion analysis procedure. Thus, there is currently a great deal of research focusing on reducing kinematic errors through error reduction methods and kinematic error estimations in relation to the reference system. However, there have been no studies that have systematically examined the effects of the selected coordinate system on the estimation of kinematic errors, because most of these previous studies have been mainly concerned with the analysis of human movement using only the human models that are provided in the commercial 3D motion capture systems. Therefore, we have estimated the differences between the results of human movement analyses using an absolute coordinate system and a relative coordinate system during a gait, in order to establish which system provides a more accurate kinematic analysis at the ankle joint. Six normal adult subjects with no neurological or orthopedic conditions, lower extremity injuries, or recent history of lower extremity surgery were used in this study. The analysis was conducted at a walking speed of 1.35m/s. For the clinical estimation, we used a cardinal plane based on the segmental reference system and the differences were plotted on the planes. From this analysis, when a relative coordinate system was in the gait analysis, the average kinematic error occurring during the gait was determined to be 13.58mm, which was significantly higher than the error generated with an absolute coordinate system. Therefore, although the relative coordinate system can also be used to calculate the ankle joint center during the clinical gait analysis, the absolute coordinate system should be employed in order to obtain more accurate joint kinematic data. In addition, the results from this study can be used as a basis to select an appropriate coordinate system with regards to the diagnostic accuracy level required for various kinds of gait disorders. This paper was recommended for publication in revised form by Associate Editor Hong Hee Yoo Yong Hoon Rim received his B.S. and M.S degrees in Bio-Mechatronic engineering from Sungkyunkwan University in 2002 and 2004, respectively. Yong Hoon Rim is currently a Researcher at the Bio-Mechatronics center and also a candidate in the biomedical Ph.D. program at Sungkyunkwan University, Korea. His research interests are in the area of digital human modeling, workspace optimization and ergonomics in digital factory. Ahn Ryul Choi received his B.S. and M.S. degrees in Bio-Mechatronic engineering from Sungkyunkwan Univer-sity in 2005 and 2007, respectively. Ahn-Ryul Choi is curr-ently a Researcher at the Bio-Mechatronics center and also a candidate in the biomedical Ph.D. program at Sungkyunkwan University, Korea. His research interests are in the area of digital human modeling and simulation. Sang Sik Lee received his Ph.D. degree from Sungkyun-kwan Universi-ty in 2000. He is currently serving as a research professor at the Bio-Mechatronics center in Sungkyunkwan University. His research interests are in the area of digital human modeling and industrial ergonomics. Kyoung Kee Min received his Ph.D degree Sungkyunkwan University in 2008. Dr. Min is currently a researcher at the Bio-Mechatronics Center in Sungkyunkwan University. Dr. Min’s research interests are in the area of disease classification using artificial neural network, digital human modeling & control. Dong Hyuk Keum received his Ph.D. degree from Seoul National University in 1979. Dr. Keum is currently a Professor at the Department of Bio-Mechat- ronic engineering at Sungkyun-kwan University, Korea. He is currently serving as the chief of an evaluation committee of the Rural Development Administrator. Dr. Keum’s research interests are in the area of simulation of post-harvest systems, quality evaluation of food materials and the processing technology. Chang Hyun Choi received his Ph.D. degree from Iowa State University in 1988. Dr. Choi is currently a Professor at the Department of Bio-Mechatronic Engineering at Sungkyunkwan University, Korea. He is currently serving as an evaluation committee of the Rural Development Administration, Korea and Korea Industrial Technology Foundation. Dr. Choi’s research interests are in the area of nondestructive quality evaluation of foods, and automatic control of off-road machinery. Joung Hwan Mun received his Ph.D. degree majoring in mechanical engineering from the University of Iowa in 1998. Dr. Mun is currently a Professor at the Department of Bio-Mechat-ronic engineering at Sungkyun-kwan University in Suwon, Korea. He is currently serving as a director of the Bio-Mechatronics center with regard to an international IMS project. Dr. Mun’s research interests are in the area of digital human modeling, sports biomechanics, bio-electronics and digital factory for human oriented production system.     

基于稳定阈度分析的外骨骼动态步长规划方法

在医疗领域,康复外骨骼机器人能够帮助下肢瘫痪的患者重新行走,因此得到广泛的关注。由于下肢截瘫患者身体的特殊性,针对该类患者使用的外骨骼机器人大多使用拐杖作为平衡辅助工具。在固定步长的情况下,不同的拐杖支撑点位置,会很大程度影响步行稳定阈度。通过分析穿戴者拄拐步态所形成的多边形支撑面,利用零力矩点(ZMP)理论计算相应的压力中心位置,从而得到四足步态的稳定阈度表达式;并在此基础上提出动态调整步长的方法,得到拐杖支撑点与步长的拟合曲面,对步长进行实时、适当调整;最后通过外骨骼机器人的运动学模型,规划相应的步态轨迹。通过在课题组自主研发的外骨骼机器人样机上进行大量对比实验,证明了在每个步态周期中,针对不同的拐杖支撑位置,提出的方法可以有效增加系统步态的稳定阈度,降低拐杖支撑点的随机性对系统稳定性的影响。     

A joint normalcy index to evaluate patients with gait pathologies in the functional aspects of joint mobility

Gait analysis using 3D motion capture systems provides joint kinematic and kinetic analysis results such as joint relative angles and moments that can be use used to evaluate the degrees of pathological gait patterns. However, the complex data produced using these 3D motion capture systems can only analyzed by experts, because the gait analysis is highly coupled to the kinematics of each joint. Therefore, several Several previous studies using gait analysis have relied on the data compression technique to represent gait deviation from the average normal profiles as a single value. Even though it is important to evaluate gait pathologies at the joint level, all these previous studies have just used a single value to evaluate the pathological gait pattern. Using just one variable for evaluation of a gait is limited in terms of determining which joint movement patterns are getting better during rehabilitation. Therefore, in this study, a method suitable for evaluating gait deviation during a gait was developed to provide three indices for the hip, knee and ankle joints. In addition, to validate the proposed method in clinical cases, experimental tests were conducted on thirty thirty-six normal walkers and six patients with cerebral palsy. Furthermore, to validate the proposed method in regards to rehabilitation, experimental tests were conducted on three classified walking groups with imposed ankle equinus constraints. The JNI for the hip joint, knee joint and ankle were 8.78 (±3.70), 2.92 (±3.25) and 8.79 (±4.38), respectively, in the normal walking group. However, these values were significantly different for the pathological walking group with cerebral palsy. The JNI of the hip joint, knee joint and ankle joint were 203.73 (±171.59), 81.23 (±52.13) and 248.39 (±149.99), respectively, for this group. There were also differences between any two of the three classified groups with imposed ankle equinus constraints. In particular, the JNI of the ankle joint was statistically different at the p<0.01 level, and this parameter clearly increased as the degree of the imposed ankle equinus was increased. These results demonstrate that the proposed JNI can be used as a scalar factor to evaluate the angular deviation of each joint in normal and patient groups. In addition, this approach can be adapted to evaluate rehabilitation and pre/post surgery.     

基于角点稳健提取的长方体参数化拟合方法

长方体基元拟合是三维点云几何拟合的典型问题,在三维重建、逆向工程、工业三维量测等实际场景中有着广泛应用。在实际应用中由于遮挡及设备盲区等原因,通常无法获取完整长方体点云数据,导致建模或量测时难以准确拟合长方体结构。针对该问题,本文提出一种结合平面拟合投影分割以及残缺平面垂角检测的长方体参数化拟合方法实现了长方体参数化拟合。首先,该方法通过平面拟合投影分割算法获取强轮廓信息的平面点云;然后,设计了残缺平面垂角检测算法,以拟合长方体真实角点;最后,利用非共面四点法对长方体残缺角点进行计算补全,获得完整的长方体参数信息。实验表明,本文方法在各类情况下均能准确检测并补全长方体角点信息以及平面参数信息,角点查准率召回率均为100%,平均误差仅为1.204×10^-3 m,能够实现精确的长方体参数化拟合。     

成像光线追踪的舌面彩色三维成像方法研究

在中医舌诊的客观化研究中,舌面的彩色三维数据能为医生提供更全面的信息,提高诊断的准确性。提出了一种基于成像光线追踪的舌面彩色三维成像方法。在成像光线追踪模型的基础上,引入光平面约束,以准确确定成像点到空间测量点的映射,结合2个线结构光传感器的扫描测量,分别获取舌头上表面及下表面完整的三维信息,并根据空间测量点到成像点的映射,完成颜色渲染,获取对应测量空间点的颜色信息。设计并研制了舌面彩色三维成像系统,进行了测量及精度验证实验,实验结果表明该方法可以准确获取舌面的彩色三维信息。     

Method for assessing the similarity and distance between curves/trials and its applications in gait analysis

In clinical assessment or sports exercise.it is common that a subject is required to repeat a specific per-formance so that a stable movement pattern is obtained and analysed.In practice,however,the trials done by a sub-ject vary more or less,depending on the psychological or physical conditions.Some of the trials can be used as rep-resentatives of the stable movement pattern,and some not.Therefore,there is a demand for a new method to identify which trials/curves are similar.The traditional methods used to assess curve similarity are not perfecfly suitable for the case where there are only a few of trials available.This study proposes a similarity-distance coefficient to assess the similarity of curves/trials.A group of designed curves are used to validate the coefficient.The results show that given joint kinematic data during gait as examples,tlle proposed coefficient call be used to quantitatively evaluate the similarity of trials,and thus find which trials would be representative(S)for the gait investigated.The proposed method could be applied in various situations where repeat movements have to be measured and analysed.     

流形网格上机构运动轨迹的参数化生成方法

在三角网格模型上操作机构的运动轨迹生成通常采用截面线法,当网格边界复杂时由此生成的运动轨迹很难保证与边界的一致性,从而产生较多较短的单条路径。基于调和映射技术,提出复杂网格曲面上机构运动轨迹参数化生成的一般方法。通过将复杂网格模型同胚映射到平面上的圆形区域或矩形区域,建立在参数曲面基础上的Zigzag型及轮廓型等参数轨迹线的具体规划模型,给出该种情况下轨迹离散点、行距及机构运动干涉的计算方法与解决方案。实例表明该轨迹生成方法具有良好的边界一致性,并因其固有的轨迹磨光性质提高了运动机构的动力学性能及运行效率。