Abstract: Based on the motion analysis, the integral dynamics model of the BYQ-3 spherical robot is introduced through the Kane equation modeling method with the characteristics of vector operation, and the simulation and experiment research are implemented. The angular velocity, angular acceleration, centroid velocity and acceleration of the spherical shell, framework and weight pendulum are defined, respectively, and the generalized rate, partial velocity, partial acceleration, generalized inertial force and generalized active force of the spherical shell, framework and weight pendulum are derived, respectively. Then, the integral dynamics model of the BYQ-3 spherical robot is proposed on the basis of derived formula above. The integral dynamics model is revised through the designed model of the moment of friction torque of the rotating joint and the couple moment of rolling torque between the ground and the spherical shell. In conditions of the line motion of which the longitude axis is parallel with the ground, the simulation is presented on the basis of revised integral dynamics model, and moreover, the open motion control experiment is also presented by using the BYQ-3 spherical robot. The results of the simulation and experiment show that considering the frication factors among the system, the integral dynamics model of the BYQ-3 spherical robot is effective.

Key words: Dynamics model, Kane equation, Spherical robot