Robust Nonprehensile Object Transport with Quadruped Robots

2026-10-05

AI Summary

This study addresses the issues of slippage and tracking errors caused by parametric uncertainties during non-prehensile transportation using quadrupedal robots. To this end, we propose a robust cooperative transportation framework that innovatively incorporates an uncertainty-aware trajectory optimization method designed to minimize closed-loop sensitivity. This approach is integrated with a coupled convex model predictive control (MPC) scheme to enable joint prediction and cooperative planning of robot-payload dynamics, while physical constraints such as ground reaction forces are rigorously enforced through whole-body quadratic programming (QP). Experimental results demonstrate that, compared to fixed-orientation and straight-line baselines, the proposed method reduces slippage by approximately 50% and 30%, respectively, and significantly decreases center-of-mass tracking errors.

Abstract

In this paper, we present a robust nonprehensile object transportation framework for quadruped robots. An uncertainty-aware trajectory optimization method generates object motions with minimal closed-loop sensitivity to uncertain parameters. The resulting reference trajectory is tracked using a coupled convex model predictive controller that jointly predicts the CoM dynamics of the quadruped and the payload followed by a whole-body QP that enforces ground reaction constraints. The approach is evaluated through extensive simulations and real-world experiments under variations in the object's inertial parameters. Its performance is compared with fixed-orientation and straight-line trajectories as baseline. The results show that the optimized object motion reduces the sliding by approximately 50% compared with the fixed-orientation baseline and 30% compared with the straight-line baseline, while also achieving lower robot CoM tracking errors.

Problem

• quadruped robots
• nonprehensile transport
• uncertainty
• object sliding
• robustness

Innovation

• Nonprehensile Transport
• Uncertainty-aware Trajectory Optimization
• Model Predictive Control
• Quadruped Robots
• Whole-body QP