Configuration control of a forklift vehicle using vision system with limited angle of view

This paper presents a configuration control of a forklift vehicle using a camera-based vision system with limited angle-of-view (AOV). The configuration (i.e., position and orientation) of the vehicle is transformed to navigation variables, which are the distance left to the goal position, the angle made by the x-axis of the target coordinate and the vehicle-to-target (v-to-t) vector, and the angle made by the x-axis of the body coordinate of the vehicle and the v-to-t vector. The kinematic equations of the forklift are derived in the navigation variables and the constraint of the motion due to the limited AOV of the camera is formulated. The control law is derived using quadratic and barrier functions as a Lyapunov function candidate. The asymptotical stability of the origin of the navigation variables is assured using the Lyapunov method. From the property of the barrier function, it can be guaranteed that the motion of the vehicle does not violate the constraint due to the limited AOV of the camera. The effectiveness of the proposed method is verified through numerical simulations.