A passive compliant non-cooperative target capture mechanism is designed to maintain the non-cooperative target on-orbit. When the relative position between capture mechanism and satellite is confirmed,a pair of four-...A passive compliant non-cooperative target capture mechanism is designed to maintain the non-cooperative target on-orbit. When the relative position between capture mechanism and satellite is confirmed,a pair of four-bar linkages lock the docking ring,which is used for connecting the satellite and the rocket. The mathematical model of capture mechanism and capture space is built by the Denavit-Hartenberg(D-H)method,and the torque of each joint is analyzed by the Lagrange dynamic equation. Besides,the capture condition and the torque of every joint under different capture conditions are analyzed by simulation in MSC. Adams. The results indicate that the mechanism can capture the non-cooperative target satellite in a wide range. During the process of capture,the passive compliant mechanism at the bottom can increase capture space,thereby reducing the difficulty and enhance stability of the capture.展开更多
A compliant F/T sensor which combines passive compliance and active sensing is proposed in thes paper to provide flexible utility. The paper describes the sensor’s mechanical design, measuring theory and kinematic eq...A compliant F/T sensor which combines passive compliance and active sensing is proposed in thes paper to provide flexible utility. The paper describes the sensor’s mechanical design, measuring theory and kinematic equations which are set up in the RPY (roll-pitch-yaw) mode.The sensor’S poSe vector can be acquired if the position signals from the PSDS are known, and vice versa. The formula between force vector and pose vector is built so that the force/ torque can be acquired after the stiffness matrix is calibrated.展开更多
悬架刚体运动学和弹性运动学特性(Kinematics and Compliance,简称K&C特性)对车辆操纵稳定性影响是至关重要,采用不同形式的导向机构的悬架系统其K&C特性不同。将K&C特性作为唯一输入变量,考察非公路车辆不同形式悬架的K&am...悬架刚体运动学和弹性运动学特性(Kinematics and Compliance,简称K&C特性)对车辆操纵稳定性影响是至关重要,采用不同形式的导向机构的悬架系统其K&C特性不同。将K&C特性作为唯一输入变量,考察非公路车辆不同形式悬架的K&C特性对操纵稳定性的影响。基于MapleSim分别建立复合连杆式、烛式、单纵臂式和双叉臂式等四种形式的独立前悬架模型,分别施加位移载荷和力载荷获取K特性和C特性并进行对比。结果表明:复合连杆式和双叉臂式悬架的K特性优于另外两种形式;四种悬架的C特性指标数值与公路车辆悬架相比均很小;C特性结果显示,非公路自卸车C特性指标数值较小,对于此类车辆悬架运动学特性主要受K特性的影响。研究方法和结论为此车辆前悬架设计研究提供参考。展开更多
The compliance modeling and rigidity performance evaluation for the lower mobility parallel manipulators are still to be remained as two overwhelming challenges in the stage of conceptual design due to their geometric...The compliance modeling and rigidity performance evaluation for the lower mobility parallel manipulators are still to be remained as two overwhelming challenges in the stage of conceptual design due to their geometric complexities. By using the screw theory, this paper explores the compliance modeling and eigencompliance evaluation of a newly patented 1T2R spindle head whose topological architecture is a 3-RPS parallel mechanism. The kinematic definitions and inverse position analysis are briefly addressed in the first place to provide necessary information for compliance modeling. By considering the 3-RPS parallel kinematic machine（PKM） as a typical compliant parallel device, whose three limb assemblages have bending, extending and torsional deflections, an analytical compliance model for the spindle head is established with screw theory and the analytical stiffness matrix of the platform is formulated. Based on the eigenscrew decomposition, the eigencompliance and corresponding eigenscrews are analyzed and the platform＇s compliance properties are physically interpreted as the suspension of six screw springs. The distributions of stiffness constants of the six screw springs throughout the workspace are predicted in a quick manner with a piece-by-piece calculation algorithm. The numerical simulation reveals a strong dependency of platform＇s compliance on its configuration in that they are axially symmetric due to structural features. At the last stage, the effects of some design variables such as structural, configurational and dimensional parameters on system rigidity characteristics are investigated with the purpose of providing useful information for the structural design and performance improvement of the PKM. Compared with previous efforts in compliance analysis of PKMs, the present methodology is more intuitive and universal thus can be easily applied to evaluate the overall rigidity performance of other PKMs with high efficiency.展开更多
基金supported by the National Natural Science Foundation of China(No.51675264)
文摘A passive compliant non-cooperative target capture mechanism is designed to maintain the non-cooperative target on-orbit. When the relative position between capture mechanism and satellite is confirmed,a pair of four-bar linkages lock the docking ring,which is used for connecting the satellite and the rocket. The mathematical model of capture mechanism and capture space is built by the Denavit-Hartenberg(D-H)method,and the torque of each joint is analyzed by the Lagrange dynamic equation. Besides,the capture condition and the torque of every joint under different capture conditions are analyzed by simulation in MSC. Adams. The results indicate that the mechanism can capture the non-cooperative target satellite in a wide range. During the process of capture,the passive compliant mechanism at the bottom can increase capture space,thereby reducing the difficulty and enhance stability of the capture.
文摘A compliant F/T sensor which combines passive compliance and active sensing is proposed in thes paper to provide flexible utility. The paper describes the sensor’s mechanical design, measuring theory and kinematic equations which are set up in the RPY (roll-pitch-yaw) mode.The sensor’S poSe vector can be acquired if the position signals from the PSDS are known, and vice versa. The formula between force vector and pose vector is built so that the force/ torque can be acquired after the stiffness matrix is calibrated.
文摘悬架刚体运动学和弹性运动学特性(Kinematics and Compliance,简称K&C特性)对车辆操纵稳定性影响是至关重要,采用不同形式的导向机构的悬架系统其K&C特性不同。将K&C特性作为唯一输入变量,考察非公路车辆不同形式悬架的K&C特性对操纵稳定性的影响。基于MapleSim分别建立复合连杆式、烛式、单纵臂式和双叉臂式等四种形式的独立前悬架模型,分别施加位移载荷和力载荷获取K特性和C特性并进行对比。结果表明:复合连杆式和双叉臂式悬架的K特性优于另外两种形式;四种悬架的C特性指标数值与公路车辆悬架相比均很小;C特性结果显示,非公路自卸车C特性指标数值较小,对于此类车辆悬架运动学特性主要受K特性的影响。研究方法和结论为此车辆前悬架设计研究提供参考。
基金Supported by National Natural Science Foundation of China(Grant No.51375013)Anhui Provincial Natural Science Foundation of China(Grant No.1208085ME64)Open Research Fund of Key Laboratory of High Performance Complex Manufacturing,Central South University(Grant No.Kfkt2013-12)
文摘The compliance modeling and rigidity performance evaluation for the lower mobility parallel manipulators are still to be remained as two overwhelming challenges in the stage of conceptual design due to their geometric complexities. By using the screw theory, this paper explores the compliance modeling and eigencompliance evaluation of a newly patented 1T2R spindle head whose topological architecture is a 3-RPS parallel mechanism. The kinematic definitions and inverse position analysis are briefly addressed in the first place to provide necessary information for compliance modeling. By considering the 3-RPS parallel kinematic machine（PKM） as a typical compliant parallel device, whose three limb assemblages have bending, extending and torsional deflections, an analytical compliance model for the spindle head is established with screw theory and the analytical stiffness matrix of the platform is formulated. Based on the eigenscrew decomposition, the eigencompliance and corresponding eigenscrews are analyzed and the platform＇s compliance properties are physically interpreted as the suspension of six screw springs. The distributions of stiffness constants of the six screw springs throughout the workspace are predicted in a quick manner with a piece-by-piece calculation algorithm. The numerical simulation reveals a strong dependency of platform＇s compliance on its configuration in that they are axially symmetric due to structural features. At the last stage, the effects of some design variables such as structural, configurational and dimensional parameters on system rigidity characteristics are investigated with the purpose of providing useful information for the structural design and performance improvement of the PKM. Compared with previous efforts in compliance analysis of PKMs, the present methodology is more intuitive and universal thus can be easily applied to evaluate the overall rigidity performance of other PKMs with high efficiency.
