Kinematic Modelling and Analysis of an Ess-board-like Robot

Considering the problem of large steering error caused by hysteresis on the passive wheel of the Essboard, a kinematic model based on coordinate transformation is proposed to improve its precision of the wheel effectively. Firstly, the holonomic constraint equation and nonholonomic constraint equation are established. The Newton iteration method is used to solve the geometric relationship between the pedal roll angle and the wheel steering angle. Then, as a verification, the virtual prototype technique(VPT) is used to obtain the measured steering angle data. Comparing with the solution of the kinematics, it is found that the average error is 0.3° and maximum error is 2.4°. After comparing with the other literature(the average error is 8.2° and the maximum error is 14.5°), it is found that the kinematic model proposed in this paper is correct and can be applied to model the motion of the Essboard. In general, this kinematic equation can be applied to the other single-track vehicles, such as motorcycle with two-wheel steering, bicycles, etc. and it has a wide application value.