In this paper, optimum positioning of cylindrical cutter for five-axis flank milling of non-developable ruled surface is addressed from the perspective of surface approximation. Based on the developed interchangeabili...In this paper, optimum positioning of cylindrical cutter for five-axis flank milling of non-developable ruled surface is addressed from the perspective of surface approximation. Based on the developed interchangeability principle, global optimization of the five-axis tool path is modeled as approximation of the tool envelope surface to the data points on the design surface following the minimum zone criterion recommended by ANSI and ISO standards for tolerance evaluation. By using the signed point-to-surface distance function, tool path plannings for semi-finish and finish millings are formulated as two constrained optimization problems in a unified framework. Based on the second order Taylor approximation of the distance function, a sequential approximation algorithm along with a hierarchical algorithmic structure is developed for the optimization. Numerical examples are presented to confirm the validity of the proposed approach.展开更多
目的观察表面肌电图在脑卒中后偏瘫患者手运动功能评估中的应用。方法 2018年1月至8月,43例脑卒中后手运动功能障碍偏瘫患者,均接受4周综合康复治疗。治疗前后,采集患侧腕屈肌、腕伸肌、指伸肌和拇短展肌表面肌电积分肌电值(iEMG)和均...目的观察表面肌电图在脑卒中后偏瘫患者手运动功能评估中的应用。方法 2018年1月至8月,43例脑卒中后手运动功能障碍偏瘫患者,均接受4周综合康复治疗。治疗前后,采集患侧腕屈肌、腕伸肌、指伸肌和拇短展肌表面肌电积分肌电值(iEMG)和均方根值(RMS),采用Fugl-Meyer评定量表(FMA)和Brunnstrom分期对患侧手功能进行评定。结果治疗后,患者患侧FMA评分,Brunnstrom分期,腕屈肌、腕伸肌、指伸肌和拇短展肌RMS和iEMG均提高(Z> 2.496, t> 5.361, P <0.05);FMA评分与各肌RMS和iEMG呈正相关(r=0.423～0.732, P <0.05);Brunnstrom分期与腕屈肌、腕伸肌和拇短展肌i EMG (r=0.343～0.467, P <0.05),指伸肌、腕伸肌和拇短展肌RMS呈正相关(r=0.223～0.328, P <0.05)。多元线性逐步回归分析显示,指伸肌RMS与腕伸肌iEMG进入FMA评分回归方程(t> 4.243, P <0.001),指伸肌RMS进入Brunnstrom分期回归方程(t=4.707, P <0.001)。结论表面肌电图可客观评估脑卒中偏瘫患者手运动功能,腕伸肌和指伸肌肌电参数更适用。展开更多
In order to present a new method for analyzing the reliability of a two-link flexible robot manipulator,Lagrange dynamics differential equations of the two-link flexible robot manipulator were established by using the...In order to present a new method for analyzing the reliability of a two-link flexible robot manipulator,Lagrange dynamics differential equations of the two-link flexible robot manipulator were established by using the integrated modal method and the multi-body system dynamics method.By using the Monte Carlo method,the random sample values of the dynamic parameters were obtained and Lagrange dynamics differential equations were solved for each random sample value which revealed their displacement,speed and acceleration.On this basis,dynamic stresses and deformations were obtained.By taking the maximum values of the stresses and the deformations as output responses and the random sample values of dynamic parameters as input quantities,extremum response surface functions were established.A number of random samples were then obtained by using the Monte Carlo method and then the reliability was analyzed by using the extremum response surface method.The results show that the extremum response surface method is an efficient and fast reliability analysis method with high-accuracy for the two-link flexible robot manipulator.展开更多
基金Supported by the National Natural Science Foundation of China (Grant Nos. 50775147 and 50835004)the National Basic Research Program of China ("973" Project) (Grant No. 2005CB724103)the Science & Technology Commission of Shanghai Municipality (Grant No. 07JC14028)
文摘In this paper, optimum positioning of cylindrical cutter for five-axis flank milling of non-developable ruled surface is addressed from the perspective of surface approximation. Based on the developed interchangeability principle, global optimization of the five-axis tool path is modeled as approximation of the tool envelope surface to the data points on the design surface following the minimum zone criterion recommended by ANSI and ISO standards for tolerance evaluation. By using the signed point-to-surface distance function, tool path plannings for semi-finish and finish millings are formulated as two constrained optimization problems in a unified framework. Based on the second order Taylor approximation of the distance function, a sequential approximation algorithm along with a hierarchical algorithmic structure is developed for the optimization. Numerical examples are presented to confirm the validity of the proposed approach.
文摘目的观察表面肌电图在脑卒中后偏瘫患者手运动功能评估中的应用。方法 2018年1月至8月,43例脑卒中后手运动功能障碍偏瘫患者,均接受4周综合康复治疗。治疗前后,采集患侧腕屈肌、腕伸肌、指伸肌和拇短展肌表面肌电积分肌电值(iEMG)和均方根值(RMS),采用Fugl-Meyer评定量表(FMA)和Brunnstrom分期对患侧手功能进行评定。结果治疗后,患者患侧FMA评分,Brunnstrom分期,腕屈肌、腕伸肌、指伸肌和拇短展肌RMS和iEMG均提高(Z> 2.496, t> 5.361, P <0.05);FMA评分与各肌RMS和iEMG呈正相关(r=0.423～0.732, P <0.05);Brunnstrom分期与腕屈肌、腕伸肌和拇短展肌i EMG (r=0.343～0.467, P <0.05),指伸肌、腕伸肌和拇短展肌RMS呈正相关(r=0.223～0.328, P <0.05)。多元线性逐步回归分析显示,指伸肌RMS与腕伸肌iEMG进入FMA评分回归方程(t> 4.243, P <0.001),指伸肌RMS进入Brunnstrom分期回归方程(t=4.707, P <0.001)。结论表面肌电图可客观评估脑卒中偏瘫患者手运动功能,腕伸肌和指伸肌肌电参数更适用。
基金Project(2006AA04Z405) supported by the National High Technology Research and Development Program of ChinaProject(3102019) supported by Beijing Municipal Natural Science Foundation,China
文摘In order to present a new method for analyzing the reliability of a two-link flexible robot manipulator,Lagrange dynamics differential equations of the two-link flexible robot manipulator were established by using the integrated modal method and the multi-body system dynamics method.By using the Monte Carlo method,the random sample values of the dynamic parameters were obtained and Lagrange dynamics differential equations were solved for each random sample value which revealed their displacement,speed and acceleration.On this basis,dynamic stresses and deformations were obtained.By taking the maximum values of the stresses and the deformations as output responses and the random sample values of dynamic parameters as input quantities,extremum response surface functions were established.A number of random samples were then obtained by using the Monte Carlo method and then the reliability was analyzed by using the extremum response surface method.The results show that the extremum response surface method is an efficient and fast reliability analysis method with high-accuracy for the two-link flexible robot manipulator.
