Stable-Balancing Motion Analysis of a Bicycle Robot with Front-Wheel Drive Based on Moment Balance

Aim at a kind of bicycle robot with front-wheel drive, stable-balancing motion is analyzed based on moment balance of inertial force and gravity in this paper. Kinematics of the robot is derived under presupposition of rolling without sliding of the two road wheels. Kinematics analysis revealed that, there are only three independent generalized speeds in the system, which can be one of the Euler Angular rates of the frame, joint angular velocity of front-fork and joint angular velocity of front-wheel. It also indicates that the robot is an under-actuated system, which holds an under-actuated degree of freedom. Dynamics of the robot is discussed by considering the equilibrium of gravity and inertial force. The model shows that the bicycle can realize stable-balancing motion under proper steering angle and driving angular velocity of front-wheel. Numerical simulations with different running situation of the robot are performed in MATLAB to analyze stable-balancing motion of the robot. The work in this paper is important to realize stable running of the bicycle robot in the future research.