A geometric approach to target convergence and obstacle avoidance of a nonstandard tractor‐trailer robot

In this article, a solution to target convergence and obstacle avoidance problem of an underactuated nonstandard n-trailer robot is proposed. With a new geometric approach, we propose autonomous velocity and steering angle controllers for the car-like tractor robot such that the tractor-trailer system moves from an initial position to a designated target. The proposed method simultaneously takes into account the dynamics constraints of the system and also ensures that the robot avoids any fixed obstacles on its way to the target. We also generalize the results to control the motion of the nonstandard n-trailer system with an arbitrary number of passive trailers, a mathematically challenging nonlinear underactuated system, given that the angular velocity of a trailer is dependent on the angular velocity of the preceding trailer. The effectiveness of the new geometric approach and the stabilizing control inputs is verified using computer simulations.