Motion Planning and Control of an Overactuated 4-Wheel Drive with Constrained Independent Steering

2025-10-21

AI Summary

To address the discontinuous omnidirectional motion of four-wheel independent steering (4WIS) robots caused by mechanical steering angle limits, this paper proposes a unified planning and control framework that ensures both motion smoothness and constraint feasibility. First, an analytical model of steering-angle constraints is established to partition the velocity space into regions enabling continuous motion. Second, an online replanning strategy—based on discontinuity surface detection—is introduced, wherein motion is temporarily halted and wheels are collaboratively repositioned to traverse singular regions. Finally, the ROS navigation stack is extended with a customized motion planner integrated with a local feedback controller. Simulation and real-world experiments demonstrate that the method achieves high-precision path tracking (mean error < 1.2 cm), dynamic obstacle avoidance, and agile omnidirectional maneuvering, significantly enhancing motion robustness and practicality for constrained over-actuated systems.

Technology Category

• Intelligent Robots: Motion and Path Planning
• Planning, Routing, and Scheduling: Replanning and Plan Repair
• Multiagent Systems: Multiagent Planning

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Applied ML and AI for Web-based mobile applications
• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs

Abstract

This paper addresses motion planning and con- trol of an overactuated 4-wheel drive train with independent steering (4WIS) where mechanical constraints prevent the wheels from executing full 360-degree rotations (swerve). The configuration space of such a robot is constrained and contains discontinuities that affect the smoothness of the robot motion. We introduce a mathematical formulation of the steering constraints and derive discontinuity planes that partition the velocity space into regions of smooth and efficient motion. We further design the motion planner for path tracking and ob- stacle avoidance that explicitly accounts for swerve constraints and the velocity transition smoothness. The motion controller uses local feedback to generate actuation from the desired velocity, while properly handling the discontinuity crossing by temporarily stopping the motion and repositioning the wheels. We implement the proposed motion planner as an extension to ROS Navigation package and evaluate the system in simulation and on a physical robot.

Problem

• Planning motion for overactuated 4-wheel independent steering with rotation constraints
• Addressing velocity discontinuities caused by mechanical steering limitations
• Developing constrained path tracking with smooth velocity transition handling

Innovation

• Mathematical formulation of steering constraints
• Motion planner accounting for swerve constraints
• Controller handles discontinuity by repositioning wheels