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arXiv · 2506.01141

Standing Tall: Sim to Real Fall Classification and Lead Time Prediction for Bipedal Robots

Gokul Prabhakaran·Jessy W. Grizzle·M. Eva Mungai
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Abstract

This paper extends a previously proposed fall prediction algorithm to a real-time (online) setting, with implementations in both hardware and simulation. The system is validated on the full-sized bipedal robot Digit, where the real-time version achieves performance comparable to the offline implementation while maintaining a zero false positive rate, an average lead time (defined as the difference between the true and predicted fall time) of 1.1s (well above the required minimum of 0.2s), and a maximum lead time error of just 0.03s. It also achieves a high recovery rate of 0.97, demonstrating its effectiveness in real-world deployment. In addition to the real-time implementation, this work identifies key limitations of the original algorithm, particularly under omnidirectional faults, and introduces a fine-tuned strategy to improve robustness. The enhanced algorithm shows measurable improvements across all evaluated metrics, including a 0.05 reduction in average false positive rate and a 1.19s decrease in the maximum error of the average predicted lead time.

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Gokul Prabhakaran, Jessy W. Grizzle, M. Eva Mungai. 2026-01-04. Standing Tall: Sim to Real Fall Classification and Lead Time Prediction for Bipedal Robots. https://arxiv.org/abs/2506.01141

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