| Quadruped robots have been widely applied for the advantage of flexible mobil e way.However most of quadruped robots have large inertia and an impact load be tween the foot endpoint and ground in the process of movement because of series c onnection way.In order to solve the problems,a new mechanism of quadruped rob ot is designed and analyzed based on the flexible joint with variable stiffness.In this paper,the main research contents and innovative results are as follows:1.First of all,the bone structure and buffer principles of the German shepherd are analyzed and a kind of series-parallel hybrid mechanism is put forward on the basis of five-bar mechanism and verified in the aspect of feasibility and rationality.The model of quadruped robot was built in Solidworks and the stress and strength of key components were also analyzed.2.For the sake of obtaining the movement equation,the kinematics of single l eg is carried through with D-H method.Through the transformation matrix of coord inate system between the body and single leg,the kinematics equation of robot is d educed,solving the Jacobi matrix of quadruped robot.3.It is import to analysis the constraints of working space of robot foot endpo int moving through the three-dimensional model.The scope of working space is gen erated and analyzed by the numerical method in MATLAB.Then the following thre e jobs can be made,deriving the singular configuration of single leg mechanism,ve rifying the reliability and security of mechanism and deducing the Jacobian matrix o f force between the joints and foot endpoint.4.Finally,the trajectory of foot endpoint of quadruped robot is planned with th e cycloid principle,and the straight movement of single leg was simulated in MAT LAB and ADAMS.By analyzing the curve of angular velocity and angular accelerat ion of each joint in a single leg,the rationality of path curves was verified,which lays the foundation for designing the control system in the further. |
