For their inherent stability and simplicity, wheeled robots are very common in robotics applications — but a major drawback of wheeled robots is their inability to navigate over large obstacles or steps without assistance. Active systems that have been designed for use on wheeled robots to lift the robot over a step — such as USU’s T3 and Virginia Tech’s IMPASS — are effective, but are limited due to the size, cost, and power required for the additional actuators. A novel, inertially actuated, passive dynamic system, excited by the motion of the robot, is introduced to allow a wheeled robot to “pop a wheelie” on each axle and hop over a step. The system investigated here is a sliding mass-spring that shifts forward and backward based on the acceleration of the base robot. By coordinating the acceleration and deceleration of the robot, the front wheels can lift over a step and the rear wheels can be pulled up afterward — both actions being a product of inertial actuation. Key advantages of this system are that the design is simple, cost-effective, and can be adjusted and retrofit to a different wheeled robot in the future with little effort. This paper presents the development of a novel inertially actuated, passive dynamic step climbing wheeled robot. Derivations of the dynamic model of the inertially actuated system are given and a computer simulation and experiments of an implementation of this sliding mass system are presented, followed by conclusions with possibilities for future work.
Cooperative Step Climbing Using Connected Wheeled Robots and Evaluation of Remote Operability
