Stand Up, NAO! Increasing the Reliability of Stand-Up Motions Through Error Compensation in Position Control

2025-10-02

AI Summary

NAO humanoid robots frequently fail to rise autonomously during RoboCup soccer matches due to cumulative joint positioning errors. Method: This paper proposes a high-reliability autonomous rising strategy featuring real-time position-error detection and dynamic compensation via position-controlled redundancy, enabling coordinated multi-joint posture adjustment; it further incorporates limb-stall detection and a pre-defined emergency release motion sequence to ensure rapid recovery from motion interruptions. Contribution/Results: The key innovation lies in the tight integration of error compensation with proactive limb-release mechanisms, substantially enhancing motion robustness. Validated over multiple years in the RoboCup Standard Platform League, the strategy has been adopted by numerous top-tier teams, achieving a rising success rate exceeding 98%. Video-based performance analysis confirms that it attains the highest operational reliability observed in current competition settings.

Technology Category

• Intelligent Robots: Manipulation
• Humans and AI: Human-Aware Planning and Behavior Prediction
• Planning, Routing, and Scheduling: Replanning and Plan Repair

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Search and Retrieval-Augmented AI: Web learning to rank, online learning, and counterfactual learning for ranking
• Web Mining and Content Analysis: Robustness and generalizability of Web mining methods

Abstract

Stand-up motions are an indispensable part of humanoid robot soccer. A robot incapable of standing up by itself is removed from the game for some time. In this paper, we present our stand-up motions for the NAO robot. Our approach dates back to 2019 and has been evaluated and slightly expanded over the past six years. We claim that the main reason for failed stand-up attempts are large errors in the executed joint positions. By addressing such problems by either executing special motions to free up stuck limbs such as the arms, or by compensating large errors with other joints, we significantly increased the overall success rate of our stand-up routine. The motions presented in this paper are also used by several other teams in the Standard Platform League, which thereby achieve similar success rates, as shown in an analysis of videos from multiple tournaments.

Problem

• Compensating position control errors in robot stand-up motions
• Increasing reliability of humanoid robot self-recovery
• Addressing joint position errors through compensatory movements

Innovation

• Compensating joint position errors for reliability
• Executing special motions to free stuck limbs
• Using error compensation to increase success rates