Vol. 1, No. 1 (July 2026) — Article KAGG:2607.00009

Predictive Contact-Aware Path Following for Agile Quadrupeds in Narrow Passages

Authors: Felix Wagner, Ananya Iyer, Meilin Jiang, Carlos Ramirez

Legged Robotics Lab, Stanford University, Stanford, CA, USA

[Received 2026-07-16; accepted 2026-07-27; published online 2026-07-30]

Abstract:

In narrow passages, the contact sequence of a quadruped's legs and the lag between commanded and realized body velocity decide whether the robot clears the gap, yet most path followers treat the body as a point with ideal velocity response. This paper presents a predictive contact-aware path follower that couples a calibrated model of the opaque velocity interface, obtained with GAUGE, with the configuration-based motion prediction of AgniNav. For each candidate command sequence, the follower predicts the realized body trajectory, the gait phase, and the swept leg envelope over a 0.5-1.0 s horizon; it schedules body poses and contact phases so that the legs nearest the passage boundary enter in a favorable phase, and it rejects passage entries whose predicted trajectory cannot clear the gap within the clearance and time budgets. The approach is evaluated in an Isaac Lab narrow-gate suite with doorway-scale gaps of 55-90 cm, rope barriers, and pipe runs, and in Unitree Go2 trials through a 72 cm doorway-scale gap and two rope barriers at setpoints of 1.0-3.0 m/s. Compared with point-body path following under an ideal velocity assumption, the method raises first-attempt success from 75.5 to 84.6 percent and shortens time to pass from 3.2 to 2.8 s, at the cost of a smaller mean clearance margin of 13.2 cm versus 15.1 cm. Removing contact-phase scheduling, future-range rejection, or the calibrated interface model reduces success to between 72.4 and 74.4 percent.


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Cite this article Felix Wagner, Ananya Iyer, Meilin Jiang, Carlos Ramirez, "Predictive Contact-Aware Path Following for Agile Quadrupeds in Narrow Passages," Transactions on Intelligent Robotics and Autonomous Systems, 2026, vol. 1, no. 1, KAGG:2607.00009. DOI: 10.5803/kagg.2607.00009.