Abstract: For the problem that the variable structure spherical mobile robot can’t turn when the climbing link mechanism is unfolding the structure of robot is improved. The new robot can do the zero-radius turning movement in two modes. Because that the rear-wheel also afford driving force so the climbing ability of variable structure spherical mobile robot is improved. The mechanics model of the new variable structure spherical mobile robot climbing slope and turning is created. Then these models are simulated by simulation software. The simulation result verifies the mechanism model’s accuracy. Then parameters which can influence the gradeability of spherical robot are analyzed. This work will be the theoretical basis of the further improvement of the new variable structure spherical mobile robot. Finally, the accuracy of the mechanical model, the validity of the climb link mechanism and the flexibility of turning are verified by the tests of mechanical model.

Key words: Climbing link mechanism, Climbing mechanics model, Spherical robot, Variable structure, Zero turn radius