Motion Planning of Cooperative Nonholonomic Mobile Manipulators

TL;DR

This paper presents a real-time motion planning framework for cooperative transportation by nonholonomic mobile manipulators, combining global path planning with a novel ellipse-based obstacle avoidance and NMPC for kinodynamic control.

Contribution

It introduces a lightweight ellipse-based obstacle region generation and a joint NMPC approach for mobile base and arm coordination in dynamic environments.

Findings

Framework achieves real-time performance in simulations and hardware tests.

Efficient obstacle avoidance with convex regions around the path.

Successful cooperative object transportation demonstrated.

Abstract

We propose a real-time implementable motion planning framework for cooperative object transportation by nonholonomic mobile manipulator robots (MMRs) in dynamic environments. Our global planner finds a path from start to goal through the static, obstacle-free regions in the environment and generates a set of convex, static, obstacle-free regions around the path using a novel, fast, and computationally lightweight ellipse-based technique. We introduce a nonlinear Model Predictive Control (NMPC) based real-time implementable planning technique that jointly plans feasible motion for the mobile base and the manipulator's arm and generates a kinodynamic feasible, collision-free trajectory for cooperative object transportation. Simulation and hardware experiments validate the efficiency of our proposed planning framework.