Bionic jumping dynamics of the musculoskeletal leg mechanism for quadruped robots

As the pneumatic artificial muscle(PAM) has flexibility properties similar to biological muscle which is widely used in robotics as one kind of actuators,the bionic mechanism driven by PAMs becomes a hot spot in robotics.In this paper,a kind of musculoskeletal leg mechanism driven by PAMs is presented,which has three joints driven by four PAMs.The jumping movement is divided into three phases.The forward and inverse kinematics of the leg mechanism in different jumping phases is derived.Considering the ground reaction force between feet and environment,the dynamic in different jumping phases is analyzed by Lagrange method,then the relationship between PAM driving force and the joints angular displacement,angular velocity,angular acceleration during one jumping cycle is obtained,which will lay a foundation for the jumping experiment of the musculoskeletal leg mechanism.