Vol. 1, No. 4 (October 2026) — Article KAGG:2610.00002

Range-Aligned Control Allocation for Agile Quadruped Navigation

Authors: Jonas Meier, Diego Navarro, Clara Fischer

Robot Dynamics Group, ETH Zurich, Zurich, Switzerland

[Received 2026-09-19; accepted 2026-09-30; published online 2026-10-03]

Abstract:

Whole-body controllers for quadrupedal robots typically distribute contact forces without knowledge of where the next obstacle will be, so stability reserves and swing clearance are allocated uniformly rather than where the upcoming motion needs them. This paper presents range-aligned control allocation, which uses a predicted future range field, computed in the style of FutureRay along the control-aligned directions of the robot, to set the weights of a whole-body quadratic program. A softmin over the field locates the predicted closest approach; stance-force weights and a linear load-shift term then bias stabilizing support toward the side opposite that approach, and a barrier-type constraint enforces swing-foot clearance only inside the predicted path corridor. All range-dependent terms scale with a field-contrast statistic that vanishes exactly when the field is uniform, and we prove that the allocator then reduces to the nominal controller, with solution deviation otherwise bounded linearly in the contrast. In an evaluation on ANYmal comprising Isaac Lab simulation across ten scenes with raised obstacles of 15 to 60 cm at 1.0 to 3.0 m/s and hardware runs beside raised obstacles, the method lowered energy per kilometer from 1334 to 1238 J/km relative to range-agnostic allocation, reduced the 95th-percentile solve time from 2.9 to 2.6 ms, and matched the unweighted controller in 99.6 percent of uniform-field evaluations. Its mean clearance margin, however, was lower (20.8 versus 24.0 cm), so the results indicate a tighter, less conservative allocation rather than uniformly larger clearance.


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Cite this article Jonas Meier, Diego Navarro, Clara Fischer, "Range-Aligned Control Allocation for Agile Quadruped Navigation," Transactions on Intelligent Robotics and Autonomous Systems, 2026, vol. 1, no. 4, KAGG:2610.00002. DOI: 10.5803/kagg.2610.00002.