Modeling and Control of AWOISV: A Filtered Tube-Based MPC Approach for Simultaneous Tracking of Lateral Position and Heading Angle

Abstract: An all-wheel omni-directional independent steering vehicle (AWOISV) is a specialized all-wheel independent steering vehicle with each wheel capable of steering up to 90{\deg}, enabling unique maneuvers like yaw and diagonal movement. This paper introduces a theoretical steering radius angle and sideslip angle (( \theta_R )-(\beta_R )) representation, based on the position of the instantaneous center of rotation relative to the wheel rotation center, defining the motion modes and switching criteria for AWOISVs. A generalized ( v)-(\beta)-(r ) dynamic model is developed with forward velocity (v), sideslip angle (\beta), and yaw rate (r) as states, and (\theta_R) and (\beta_R) as control inputs. This model decouples longitudinal and lateral motions into forward and rotational motions, allowing seamless transitions across all motion modes under specific conditions. A filtered tube-based linear time-varying MPC (FT-LTVMPC) strategy is proposed, achieving simultaneous tracking of lateral position and arbitrary heading angles, with robustness to model inaccuracies and parameter uncertainties. Co-simulation and hardware-in-loop (HIL) experiments confirm that FT-LTVMPC enables high-precision control of both position and heading while ensuring excellent real-time performance.