Motion Planning of Nonholonomic Cooperative Mobile Manipulators

2025-02-08

AI Summary

This work addresses the cooperative object transport task for nonholonomic mobile manipulator robots (MMRs) in environments with static and dynamic obstacles. Methodologically, it proposes an integrated framework combining offline global planning with online coordinated control. It introduces, for the first time, a convex polygonal constraint-space modeling technique based on visibility vertices; unifies nonlinear model predictive control (NMPC) for simultaneous base and manipulator trajectory planning, explicitly coupling kinematics, dynamics, and nonholonomic constraints; and integrates real-time trajectory optimization with torque limiting for safety and feasibility. Evaluated in simulation and on multiple hardware platforms, the system achieves multi-arm cooperative manipulation, dynamic obstacle avoidance, and high-precision trajectory tracking at a planning frequency ≥10 Hz. All solutions strictly satisfy kinematic feasibility, dynamic feasibility, and safety requirements throughout execution.

Technology Category

• Intelligent Robots: Manipulation
• Planning, Routing, and Scheduling: Mixed Discrete/Continuous Planning
• Multiagent Systems: Multiagent Planning

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• 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

We propose a real-time implementable motion planning technique for cooperative object transportation by nonholonomic mobile manipulator robots (MMRs) in an environment with static and dynamic obstacles. The proposed motion planning technique works in two steps. A novel visibility vertices-based path planning algorithm computes a global piece-wise linear path between the start and the goal location in the presence of static obstacles offline. It defines the static obstacle free space around the path with a set of convex polygons for the online motion planner. We employ a Nonliner Model Predictive Control (NMPC) based online motion planning technique for nonholonomic MMRs that jointly plans for the mobile base and the manipulators arm. It efficiently utilizes the locomotion capability of the mobile base and the manipulation capability of the arm. The motion planner plans feasible motion for the MMRs and generates trajectory for object transportation considering the kinodynamic constraints and the static and dynamic obstacles. The efficiency of our approach is validated by numerical simulation and hardware experiments in varied environments.

Problem

• Real-time motion planning for nonholonomic mobile manipulators
• Handling static and dynamic obstacles in cooperative transportation
• Combining global path planning with online NMPC for efficiency

Innovation

• Visibility vertices-based path planning
• Nonlinear Model Predictive Control
• Cooperative object transportation