The lightweight and high efficiency of natural structures are the inexhaustible sources for engineering improvements. The goal of the study is to find innovative solutions for mechanical lightweight design through the...The lightweight and high efficiency of natural structures are the inexhaustible sources for engineering improvements. The goal of the study is to find innovative solutions for mechanical lightweight design through the application of structural bionic approaches. Giant waterlily leaf ribs and cactus stem are investigated for their optimal framework and superior performance. Their structural characteristics are extracted and used in the bio-inspired design of Lin MC6000 gantry machining center crossbeam. By mimicking analogous network structure, the bionic model is established, which has better load-carrying capacity than conventional distribution. Finite Element Method （FEM） is used for numerical simulation. Results show better specific stiffness of the bionic model, which is increased by 17.36%. Finally the scaled models are fabricated by precision casting for static and dynamic tests. The physical experiments are compared to numerical simulation. The results show that the maximum static deformation of the bionic model is reduced by about 16.22%, with 3.31% weight reduction. In addition, the first four natural frequencies are improved obviously. The structural bionic design is a valuable reference for updating conventional mechanical structures with better performance and less material consumption.展开更多
为了降低标准阶背式MIRA(Motor Industry Research Association)模型的气动阻力,设计了四种仿生非光滑单元体:仿生树叶菱形凸台、仿生海螺状凸台、仿生贝壳凹槽、仿生鱼尾楔形凸台。采用正交试验法,系统分析了这些单元体的安装位置、安...为了降低标准阶背式MIRA(Motor Industry Research Association)模型的气动阻力,设计了四种仿生非光滑单元体:仿生树叶菱形凸台、仿生海螺状凸台、仿生贝壳凹槽、仿生鱼尾楔形凸台。采用正交试验法,系统分析了这些单元体的安装位置、安装间距、形状、高度和宽度对气动性能的影响。结果表明:影响减阻效果主次因素为非光滑单元体安装位置,安装间距、形状、高度和宽度;最优组合为在车尾安装仿生楔形鱼尾凸台(高度为11 mm,宽度为21 mm,间距为50 mm),其阻力系数(C_(D))为0.2950,相较于原MIRA模型减阻率达到了9.006%。流场分析表明,最优组合非光滑单元体能够增加MIRA模型尾部分离区流场的能量,减小尾涡面积,有效降低气动阻力。展开更多
A bionic flexible manipulator driven by pneumatic muscle actuator(PMA)can better reflect the flexibility of the mechanism.Current research on PMA mainly focuses on the modeling and control strategy of the pneumatic ma...A bionic flexible manipulator driven by pneumatic muscle actuator(PMA)can better reflect the flexibility of the mechanism.Current research on PMA mainly focuses on the modeling and control strategy of the pneumatic manipulator system.Compared with traditional electro-hydraulic actuators,the structure of PMA is simple but possesses strong nonlinearity and flexibility,which leads to the difficulty in improving the control accuracy.In this paper,the configuration design of a bionic flexible manipulator is performed by human physiological map,the kinematic model of the mechanism is established,and the dynamics is analyzed by Lagrange method.A fuzzy torque control algorithm is designed based on the computed torque method,where the fuzzy control theory is applied.The hardware experimental system is established.Through the co-simulation contrast test on MATLAB and ADAMS,it is found that the fuzzy torque control algorithm has better tracking performance and higher tracking accuracy than the computed torque method,and is applied to the entity control test.The experimental results show that the fuzzy torque algorithm can better control the trajectory tracking movement of the bionic flexible manipulator.This research proposes a fuzzy torque control algorithm which can compensate the error more effectively,and possesses the preferred trajectory tracking performance.展开更多
基金Acknowledgements The research was sponsored by the Natural Science Foundation of China （50975012）, and the Scientific Research Foundation for the Outstanding Young Scientist of Shandong Province （2008BS05007）.
文摘The lightweight and high efficiency of natural structures are the inexhaustible sources for engineering improvements. The goal of the study is to find innovative solutions for mechanical lightweight design through the application of structural bionic approaches. Giant waterlily leaf ribs and cactus stem are investigated for their optimal framework and superior performance. Their structural characteristics are extracted and used in the bio-inspired design of Lin MC6000 gantry machining center crossbeam. By mimicking analogous network structure, the bionic model is established, which has better load-carrying capacity than conventional distribution. Finite Element Method （FEM） is used for numerical simulation. Results show better specific stiffness of the bionic model, which is increased by 17.36%. Finally the scaled models are fabricated by precision casting for static and dynamic tests. The physical experiments are compared to numerical simulation. The results show that the maximum static deformation of the bionic model is reduced by about 16.22%, with 3.31% weight reduction. In addition, the first four natural frequencies are improved obviously. The structural bionic design is a valuable reference for updating conventional mechanical structures with better performance and less material consumption.
文摘为了降低标准阶背式MIRA(Motor Industry Research Association)模型的气动阻力,设计了四种仿生非光滑单元体:仿生树叶菱形凸台、仿生海螺状凸台、仿生贝壳凹槽、仿生鱼尾楔形凸台。采用正交试验法,系统分析了这些单元体的安装位置、安装间距、形状、高度和宽度对气动性能的影响。结果表明:影响减阻效果主次因素为非光滑单元体安装位置,安装间距、形状、高度和宽度;最优组合为在车尾安装仿生楔形鱼尾凸台(高度为11 mm,宽度为21 mm,间距为50 mm),其阻力系数(C_(D))为0.2950,相较于原MIRA模型减阻率达到了9.006%。流场分析表明,最优组合非光滑单元体能够增加MIRA模型尾部分离区流场的能量,减小尾涡面积,有效降低气动阻力。
基金Supported by National Natural Science Foundation of China(Grant No.51405229)Jiangsu Provincial Natural Science Foundation of China(Grant No.BK20151470)
文摘A bionic flexible manipulator driven by pneumatic muscle actuator(PMA)can better reflect the flexibility of the mechanism.Current research on PMA mainly focuses on the modeling and control strategy of the pneumatic manipulator system.Compared with traditional electro-hydraulic actuators,the structure of PMA is simple but possesses strong nonlinearity and flexibility,which leads to the difficulty in improving the control accuracy.In this paper,the configuration design of a bionic flexible manipulator is performed by human physiological map,the kinematic model of the mechanism is established,and the dynamics is analyzed by Lagrange method.A fuzzy torque control algorithm is designed based on the computed torque method,where the fuzzy control theory is applied.The hardware experimental system is established.Through the co-simulation contrast test on MATLAB and ADAMS,it is found that the fuzzy torque control algorithm has better tracking performance and higher tracking accuracy than the computed torque method,and is applied to the entity control test.The experimental results show that the fuzzy torque algorithm can better control the trajectory tracking movement of the bionic flexible manipulator.This research proposes a fuzzy torque control algorithm which can compensate the error more effectively,and possesses the preferred trajectory tracking performance.
