Pure Rolling Steering System Design and Research for Wheeled Mobile Robot

In order to solve the problem of the side slip of the wheeled mobile robot adopting the steering trapezium, a novel pure rolling steering system for wheeled mobile robot is designed. It takes advantage of synchronous belt characteristic with long-distance, variable-direction and precise transmission and is equipped with a dual power differential drive axle. This paper details the design points of the whole mechanism; sets up the kinematic models of four-wheeled Ackerman steering, crab movement, and pivot turn modes; and then the steering drive control strategies of various modes of the robot is established. A prototype equipped with a control system consisting of a control center, four steering motors, two drive motors, an electromagnetic clutch and four angle sensors is constructed. Finally, the test results for pivot turn and four-wheel minimum radius steering on the hard road shows that the trajectory slip error are less than 0.2% and 1.7%, respectively. This verifies clearly the correctness and effectiveness of the proposed pure rolling steering system for wheeled mobile robot.