Modelling and control of all-wheel omnidirectional independent steering vehicle: a filtered tube-based MPC approach for simultaneous tracking of lateral position and heading angle

An all-wheel omni-directional independent steering vehicle (AWOISV) is a specialised all-wheel independent steering vehicle with each wheel capable of steering up to ±90∘, enabling unique manoeuvres like yaw and diagonal movement. This paper introduces a theoretical steering radius angle and sideslip angle (θR–βR) representation, based on the position of the instantaneous centre of rotation relative to the wheel rotation centre, defining the motion modes and switching criteria for AWOISVs. A generalised v–β–r dynamic model is developed with forward velocity v, sideslip angle β, and yaw rate r as states, and θR and βR 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.