Kinodynamic Motion Planning for Collaborative Object Transportation by Multiple Mobile Manipulators

TL;DR

This work tackles the challenge of kinodynamic motion planning for cooperative transport of a rigid object by multiple mobile manipulators in environments with static and dynamic obstacles. It introduces a two-stage framework: offline generation of obstacle-free regions prioritizing narrow passages through targeted seeding, followed by online nonlinear model predictive control that jointly optimizes the mobile bases and arms within kinodynamic and collision constraints. The method achieves real-time performance, demonstrates robust dynamic obstacle avoidance, and outperforms state-of-the-art approaches in both simulations and hardware experiments. The results indicate strong potential for scalable, real-time deployment in industrial and service robotics scenarios.

Abstract

This work proposes a kinodynamic motion planning technique for collaborative object transportation by multiple mobile manipulators in dynamic environments. A global path planner computes a linear piecewise path from start to goal. A novel algorithm detects the narrow regions between the static obstacles and aids in defining the obstacle-free region to enhance the feasibility of the global path. We then formulate a local online motion planning technique for trajectory generation that minimizes the control efforts in a receding horizon manner. It plans the trajectory for finite time horizons, considering the kinodynamic constraints and the static and dynamic obstacles. The planning technique jointly plans for the mobile bases and the arms to utilize the locomotion capability of the mobile base and the manipulation capability of the arm efficiently. We use a convex cone approach to avoid self-collision of the formation by modifying the mobile manipulators admissible state without imposing additional constraints. Numerical simulations and hardware experiments showcase the efficiency of the proposed approach.

Figures (18)

• Figure 1: Formation definition in 3D. The uniform dashed shapes are the projection of the formation in the ground plane.
• Figure 2: Formation definition in 2D. The blue color rectangles represent MMR bases with their body coordinate. The red line indicates the manipulators. The light green area represents the object to be carried by the MMRs.
• Figure 3: Motion Planning overview.
• Figure 4: Path planning process.
• Figure 5: Seeding Points for the polygon generation in narrow gaps between the obstacle. The points are sorted from 1-5 in accordance to their edge length. Polygon generation starts from point 1, and the points 4, 5 are discarded as they are inside the previously generated polygons