Dynamic analysis for the leg mechanism of a wheel-leg hybrid rescue robot

The inverse dynamic of the leg with a (2-UPS+U)R series-parallel mechanism of the hybrid rescue robot is analyzed in this paper. First, the constrained relationships in the leg are determined, and the 6×6 Jacobian matrices of the series-parallel leg are derived and presented. Second, the velocity, acceleration, angular velocity and acceleration of center of mass in each link are solved and the dynamic model of the series-parallel leg is established with virtual work principle and its standard Lagrange formula are presented in detail. In the end, the numerical simulation of the series-parallel leg is carried out. The dynamic equations of the leg lay the foundation for a number of computational algorithms that are useful in the later control, simulation, animation and built the hybrid rescue robot prototype.