The dynamic dexterity is an important issue for manipulator design, some indices were proposed for analyzing dynamic dexterity, but they can evaluate the dynamic performance just at one pose in the workspaee of the ma...The dynamic dexterity is an important issue for manipulator design, some indices were proposed for analyzing dynamic dexterity, but they can evaluate the dynamic performance just at one pose in the workspaee of the manipulator, and can＇t be applied to dynamic design expediently. Much work has been done in the kinematic optimization, but the work in the dynamic optimization is much less. A global dynamic condition number index is proposed and applied to the dynamic optimization design the parallel manipulator. This paper deals with the dynamic manipulability and dynamic optimization of a two degree-of-freedom （DOF） parallel manipulator. The particular velocity and particular angular velocity matrices of each moving part about the part＇s pivot point are derived fi＇om the kinematic formulation of the manipulator, and the inertial force and inertial movement are obtained utilizing Newton-Euler formulation, then the inverse dynamic model of the parallel manipulator is proposed based on the virtual work principle. The general inertial ellipsoid and dynamic manipulability ellipsoid are applied to evaluate the dynamic performance of the manipulator, a global dynamic condition number index based on the condition number of general inertial matrix in the workspace is proposed, and then the link lengths of the manipulator is redesigned to optimize the dynamic manipulability by this index. The dynamic manipulability of the origin mechanism and the optimized mechanism are compared, the result shows that the optimized one is much better. The global dynamic condition number index has good effect in evaluating the dynamic dexterity of the whole workspace, and is efficient in the dynamic optimal design of the parallel manipulator.展开更多
A quadruped robot with a manipulator that combines dynamic motion and manipulation capabilities will greatly expand its application scenarios.However,the addition of the manipulator raises the center of mass of the qu...A quadruped robot with a manipulator that combines dynamic motion and manipulation capabilities will greatly expand its application scenarios.However,the addition of the manipulator raises the center of mass of the quadruped robot,increasing complexity in motion control and posing new challenges for maintaining balance on sloped terrains.To address this,a balance control method based on whole-body synergy is proposed in this study,emphasizing adaptive adjustment of the robot system’s overall balance through effective utilization of the manipulator’s active motion.By establishing a mapping relationship between the manipulator and the robot’s attitude angle under system equilibrium,the desired manipulator motion is guided by real-time estimates of terrain angles during motion,enhancing motion efficiency while ensuring robot balance.Furthermore,to enhance motion tracking accuracy,the optimization of system angular momentum and manipulator manipulability is incorporated into hierarchical optimization tasks,improving manipulator controllability and overall system performance.Simulation and experimental results demonstrate that the quadruped robot with a manipulator exhibits reduced velocity and attitude angle fluctuations,as well as smoother foot-end force dynamics during climbing motions with the addition of manipulator adaptive adjustment.These results validate the effectiveness and superiority of the manipulator-based adaptive adjustment strategy proposed in this paper.展开更多
基金supported by National Natural Science Foundation of China (Grant No. 50605041, No. 50775125)National Basic Research Program of China (973 Program, Grant No. 2006CB705400)
文摘The dynamic dexterity is an important issue for manipulator design, some indices were proposed for analyzing dynamic dexterity, but they can evaluate the dynamic performance just at one pose in the workspaee of the manipulator, and can＇t be applied to dynamic design expediently. Much work has been done in the kinematic optimization, but the work in the dynamic optimization is much less. A global dynamic condition number index is proposed and applied to the dynamic optimization design the parallel manipulator. This paper deals with the dynamic manipulability and dynamic optimization of a two degree-of-freedom （DOF） parallel manipulator. The particular velocity and particular angular velocity matrices of each moving part about the part＇s pivot point are derived fi＇om the kinematic formulation of the manipulator, and the inertial force and inertial movement are obtained utilizing Newton-Euler formulation, then the inverse dynamic model of the parallel manipulator is proposed based on the virtual work principle. The general inertial ellipsoid and dynamic manipulability ellipsoid are applied to evaluate the dynamic performance of the manipulator, a global dynamic condition number index based on the condition number of general inertial matrix in the workspace is proposed, and then the link lengths of the manipulator is redesigned to optimize the dynamic manipulability by this index. The dynamic manipulability of the origin mechanism and the optimized mechanism are compared, the result shows that the optimized one is much better. The global dynamic condition number index has good effect in evaluating the dynamic dexterity of the whole workspace, and is efficient in the dynamic optimal design of the parallel manipulator.
基金supported by the Gansu Youth Science and Technology Fund(24JRRA189).
文摘A quadruped robot with a manipulator that combines dynamic motion and manipulation capabilities will greatly expand its application scenarios.However,the addition of the manipulator raises the center of mass of the quadruped robot,increasing complexity in motion control and posing new challenges for maintaining balance on sloped terrains.To address this,a balance control method based on whole-body synergy is proposed in this study,emphasizing adaptive adjustment of the robot system’s overall balance through effective utilization of the manipulator’s active motion.By establishing a mapping relationship between the manipulator and the robot’s attitude angle under system equilibrium,the desired manipulator motion is guided by real-time estimates of terrain angles during motion,enhancing motion efficiency while ensuring robot balance.Furthermore,to enhance motion tracking accuracy,the optimization of system angular momentum and manipulator manipulability is incorporated into hierarchical optimization tasks,improving manipulator controllability and overall system performance.Simulation and experimental results demonstrate that the quadruped robot with a manipulator exhibits reduced velocity and attitude angle fluctuations,as well as smoother foot-end force dynamics during climbing motions with the addition of manipulator adaptive adjustment.These results validate the effectiveness and superiority of the manipulator-based adaptive adjustment strategy proposed in this paper.
