Technical Paper
A path tracking method for an unmanned bicycle based on the body-fixed coordinate frame
2024-04-09
2024-01-2303
The paper presents a trajectory tracking method for an unmanned bicycle in its local body-fixed coordinate frame. A bicycle is regarded as a multibody system consisting of four rigid bodies which are named front wheel, front fork, body frame, and rear wheel. Unlike many studies before, the interaction between tire and road is regarded as tire force instead of a nonholonomic constraint. The body frame has six degrees of freedom and the rear wheel and front fork have one degree of freedom relative to the body frame respectively. The front wheel has one degree of freedom relative to the front fork. Thus, a bike has nine degrees of freedom in total. The kinetic energy of a bike is expressed using quasi-coordinates in the local body-fixed coordinate frame which has a simpler form than using absolute coordinates in the global frame. The dynamic model can be acquired by submitting the expression of kinetic energy into the Lagrange equation.