Presents a fast and effective method proposed by combining the fuzzy C means (FCM) and the fuzzy neural network for solving robot inverse kinematics, and its successful application to the robot inverse kinematics and ...Presents a fast and effective method proposed by combining the fuzzy C means (FCM) and the fuzzy neural network for solving robot inverse kinematics, and its successful application to the robot inverse kinematics and concludes from simulation results that this new method not only has high efficiency and accuracy, but also good generalization, and it also overcomes the "dimension disaster" of fuzzy set in a fuzzy neural network fairly well.展开更多
This article proposes a new algorithm of quaternion and dual quaternion in matrix form. It applies quaternion in special cases of rotated plane, transforming the sine and cosine of the rotation angle into matrix form,...This article proposes a new algorithm of quaternion and dual quaternion in matrix form. It applies quaternion in special cases of rotated plane, transforming the sine and cosine of the rotation angle into matrix form, then exporting flat quaternions base in two matrix form. It establishes serial 6R manipulator kinematic equations in the form of quaternion matrix. Then five variables are eliminated through linear elimination and application of lexicographic Groebner base. Thus, upper bound of the degree of the equation is determined, which is 16. In this way, a 16-degree equation with single variable is obtained without any extraneous root. This is the first time that quaternion matrix modeling has been used in 6R robot inverse kinematics analysis.展开更多
目的:不同年龄的膝骨关节炎患者采取何种坐起策略尚未达成共识。为此,文章通过Meta分析系统评估不同年龄的膝骨关节炎患者与健康人坐起的生物力学特征,分析不同年龄患者的坐起运动模式,为改善患者坐起功能提供参考。方法:截至2023年3月,...目的:不同年龄的膝骨关节炎患者采取何种坐起策略尚未达成共识。为此,文章通过Meta分析系统评估不同年龄的膝骨关节炎患者与健康人坐起的生物力学特征,分析不同年龄患者的坐起运动模式,为改善患者坐起功能提供参考。方法:截至2023年3月,在PubMed、Web of Science和中国知网等数据库进行文献检索,纳入膝骨关节炎患者和健康人群坐起的生物力学特征的观察性研究,要求研究对象为膝关节影像学Kellgren-Lawrence严重程度分级≥Ⅰ级的50岁以上的膝骨关节炎患者,且定期出现膝关节疼痛,并根据纳入排除标准对受试者进行年龄(50-60岁vs.60岁以上)及严重程度(轻中度患者vs.重度患者)亚组分析。运用Down and black改良量表进行文献质量评价,采用Stata 16.0软件进行亚组分析确定不同年龄与严重程度的膝骨关节炎患者坐起的生物力学特征。结果:共14项随机对照试验(824例受试者)纳入Meta分析,所有纳入文献质量平均得分为76.2分,评分范围为66.7-86.7分,均达到中、高质量,具有一定代表性。Meta分析结果发现:①相比健康人,膝骨关节炎患者坐起总时长(SMD=0.92,95%CI:0.76-1.09,P<0.001)、伸展阶段时长(SMD=0.46,95%CI:0.18-0.74,P=0.001)更久;相比膝骨关节炎轻中度患者,重度患者总时长增加更明显(P<0.001),且60岁以上患者比50-60岁患者伸展阶段时长增加更明显(P=0.001)。②相比健康人,膝骨关节炎患者坐起躯干屈曲活动度(SMD=0.64,95%CI:0.37-0.91,P<0.001)更大;膝关节屈曲活动度(SMD=-0.47,95%CI:-0.70至-0.24,P<0.001)和踝关节背屈活动度(SMD=-0.32,95%CI:-0.56至-0.08,P=0.01)更小,且60岁以上患者的膝关节屈曲活动度比50-60岁患者下降更明显(P<0.001)。③膝骨关节炎患者髋关节屈曲力矩峰值(SMD=-0.57,95%CI:-0.83至-0.31,P<0.001)、膝关节伸展力矩峰值(SMD=-0.83,95%CI:-1.08至-0.59,P<0.001)更小。结论:①60岁以上膝骨关节炎患者比50-60岁患者坐起缓冲和伸展阶段的时长更久,且严重程度等级高的患者坐起总时长增加更明显,高龄与膝骨关节炎严重患者坐起时长增加,可能会使软骨承受负荷的持续时间增加,进一步加剧膝关节疼痛症状,增加该人群坐起难度。②膝骨关节炎患者表现出膝、踝关节屈曲活动度受限,且60岁以上患者膝关节活动度更为受限。③膝骨关节炎患者的髋关节屈曲、膝关节伸展力矩峰值减小,这可能是缓解疼痛的补偿策略。展开更多
An analytic inverse kinematic solution is presented for a 7-DOF(degree of freedom)redundant space manipulator.The proposed method can obtain all the feasible solutions in the global joint space,which are denoted by a ...An analytic inverse kinematic solution is presented for a 7-DOF(degree of freedom)redundant space manipulator.The proposed method can obtain all the feasible solutions in the global joint space,which are denoted by a joint angle parameter.Meanwhile,both the singularity problem and the joint limits are considered in detail.Besides,an optimization approach is provided to get one near optimal inverse kinematic solution from all the feasible solutions.The proposed method can reduce effectively the computational complexity,so that it can be applied online.Finally,the method’s validity is shown by kinematic simulations.展开更多
文摘Presents a fast and effective method proposed by combining the fuzzy C means (FCM) and the fuzzy neural network for solving robot inverse kinematics, and its successful application to the robot inverse kinematics and concludes from simulation results that this new method not only has high efficiency and accuracy, but also good generalization, and it also overcomes the "dimension disaster" of fuzzy set in a fuzzy neural network fairly well.
文摘This article proposes a new algorithm of quaternion and dual quaternion in matrix form. It applies quaternion in special cases of rotated plane, transforming the sine and cosine of the rotation angle into matrix form, then exporting flat quaternions base in two matrix form. It establishes serial 6R manipulator kinematic equations in the form of quaternion matrix. Then five variables are eliminated through linear elimination and application of lexicographic Groebner base. Thus, upper bound of the degree of the equation is determined, which is 16. In this way, a 16-degree equation with single variable is obtained without any extraneous root. This is the first time that quaternion matrix modeling has been used in 6R robot inverse kinematics analysis.
文摘目的:不同年龄的膝骨关节炎患者采取何种坐起策略尚未达成共识。为此,文章通过Meta分析系统评估不同年龄的膝骨关节炎患者与健康人坐起的生物力学特征,分析不同年龄患者的坐起运动模式,为改善患者坐起功能提供参考。方法:截至2023年3月,在PubMed、Web of Science和中国知网等数据库进行文献检索,纳入膝骨关节炎患者和健康人群坐起的生物力学特征的观察性研究,要求研究对象为膝关节影像学Kellgren-Lawrence严重程度分级≥Ⅰ级的50岁以上的膝骨关节炎患者,且定期出现膝关节疼痛,并根据纳入排除标准对受试者进行年龄(50-60岁vs.60岁以上)及严重程度(轻中度患者vs.重度患者)亚组分析。运用Down and black改良量表进行文献质量评价,采用Stata 16.0软件进行亚组分析确定不同年龄与严重程度的膝骨关节炎患者坐起的生物力学特征。结果:共14项随机对照试验(824例受试者)纳入Meta分析,所有纳入文献质量平均得分为76.2分,评分范围为66.7-86.7分,均达到中、高质量,具有一定代表性。Meta分析结果发现:①相比健康人,膝骨关节炎患者坐起总时长(SMD=0.92,95%CI:0.76-1.09,P<0.001)、伸展阶段时长(SMD=0.46,95%CI:0.18-0.74,P=0.001)更久;相比膝骨关节炎轻中度患者,重度患者总时长增加更明显(P<0.001),且60岁以上患者比50-60岁患者伸展阶段时长增加更明显(P=0.001)。②相比健康人,膝骨关节炎患者坐起躯干屈曲活动度(SMD=0.64,95%CI:0.37-0.91,P<0.001)更大;膝关节屈曲活动度(SMD=-0.47,95%CI:-0.70至-0.24,P<0.001)和踝关节背屈活动度(SMD=-0.32,95%CI:-0.56至-0.08,P=0.01)更小,且60岁以上患者的膝关节屈曲活动度比50-60岁患者下降更明显(P<0.001)。③膝骨关节炎患者髋关节屈曲力矩峰值(SMD=-0.57,95%CI:-0.83至-0.31,P<0.001)、膝关节伸展力矩峰值(SMD=-0.83,95%CI:-1.08至-0.59,P<0.001)更小。结论:①60岁以上膝骨关节炎患者比50-60岁患者坐起缓冲和伸展阶段的时长更久,且严重程度等级高的患者坐起总时长增加更明显,高龄与膝骨关节炎严重患者坐起时长增加,可能会使软骨承受负荷的持续时间增加,进一步加剧膝关节疼痛症状,增加该人群坐起难度。②膝骨关节炎患者表现出膝、踝关节屈曲活动度受限,且60岁以上患者膝关节活动度更为受限。③膝骨关节炎患者的髋关节屈曲、膝关节伸展力矩峰值减小,这可能是缓解疼痛的补偿策略。
基金the National 863 Program of China(2012AA041403)the National Natural Science Foundation of China(61305107)
文摘An analytic inverse kinematic solution is presented for a 7-DOF(degree of freedom)redundant space manipulator.The proposed method can obtain all the feasible solutions in the global joint space,which are denoted by a joint angle parameter.Meanwhile,both the singularity problem and the joint limits are considered in detail.Besides,an optimization approach is provided to get one near optimal inverse kinematic solution from all the feasible solutions.The proposed method can reduce effectively the computational complexity,so that it can be applied online.Finally,the method’s validity is shown by kinematic simulations.
