Backward-motion control of a mobile robot with n passive off-hooked trailers

Abstract

A passive multiple-trailer system provides various practical advantages for multi-functional service robots. However, motion control is difficult because the kinematic model is highly nonlinear. The kinematic design of a trailer system was proposed in prior research of ours. In this paper, it is shown how the backward motion of a robot with n passive trailers can be controlled. Once the desired trajectory of the last trailer is computed, the control input of the pushing robot is obtained through the proposed control scheme. Some experimental issues on reversing the trailer system are addressed. This paper provides an answer to the following question: "Does the system work well even if there are sensing or modeling errors?" Although it is difficult to obtain general analytic solutions for the above research question, a practical answer will be explored though simplified analysis and experiments. Experimental verifications are carried out using a mobile robot with three passive trailers. The experimental results show that backward-motion control can be successfully carried out by applying the proposed control scheme.

Cascaded VFO Control for Non-Standard N-Trailer Robots

“…The concept 7 Velocities of the last trailer have been computed by using the tractor control inputs and propagation formula (11).…”

“…A structure of the proposed control system is a direct consequence of N-trailer kinematics, which can be formulated in the form of cascaded interconnection of unicycle subsystems with velocities resulting from propagation of tractor control inputs along a vehicle kinematic chain. Application of the cascaded control into nSNT robots is not a completely new idea-is was independently proposed in [7,25] for the straight-line backward tracking task under a special assumption of a vehicle construction (where all the hitching distances and all the trailer lengths are equal), and in [21] for the backward path following task. In contrast, the approach proposed in the current paper presents a unified solution to the set-point and trajectory tracking control tasks for nSNT vehicles by utilization of the VFO controller [18] in an outer loop of a cascade.…”

Cascade-Like Modular Tracking Controller for non-Standard N-Trailers

“…To the author's best knowledge, the only trajectory-tracking control (TTC) method elaborated for truly nSNT vehicles has been proposed in [5] employing a cascade-like concept (see also [28]), independently investigated in [17]. The cascade-like approach has revealed its big potential; however, Chung et al [5] restricted their considerations only to the special case of backward tracking of constant-curvature reference trajectories assuming omni-directional kinematics of a tractor and common positive lengths of all the hitching offsets equal to the trailer lengths.…”

The Synthesis of Steering Rules for Stabilizing Road Train Reverse Motion to Solve the Task of Reaching a Set Goal

“…It should be noted that works in this direction are actively conducted abroad in the abstractive aspect using varied mathematical tools [1][2][3][4][5] as well as in the empirical one [2,[6][7][8] during recent years. The synthesis of several possible steering laws is accomplished during the conducted research.…”