Dynamics analysis of leg mechanism of six-legged firefighting robot

A novel 3-DOF Leg mechanism (LM), which consists of a 2RUS+RU PM, a space parallelogram mechanism and a connecting spherical joint is proposed. The LM has good protective characteristics. The whole LM is driven by the 2RUS+RU PM. The kinematics formulae and the inertial force formulae at their mass centers of moving links are derived. Based on the principle of virtue work, the dynamics formula is built for solving the dynamic driving force of the LM. An analytic example on the kinematics and dynamics is given. The kinematics and dynamics results of the example are verified by a simulation model of the LM. On the basis of the kinematics results, motion characteristics of the LM are analyzed and the leg layout of the robot is determined. The LM is improved according to the dynamics results. The dynamic model of improved LM is established. The workspace of improved LM is drawn.