Organizations: College of Information Science and Technology, Eastern Institute of Technology, Ningbo, P. R. China. · University of Maryland, USA. · School of Computer Science, University of Nottingham, UK. · The Hong Kong Polytechnic University, Hong Kong. · Xi’an Jiaotong-Liverpool University, China. · Eastern Institute of Technology, Ningbo, P. R. China.
In this paper, we present a Goal-Aware Uncertainty-Guided Exploration (GAUGE) framework for planner-conditioned active calibration of opaque quadruped velocity interfaces. Commercial quadrupeds commonly expose planar-velocity commands, but the underlying locomotion controller remains inaccessible and can produce systematic discrepancies between commanded and realized motion. A navigation planner typically uses a structured subset of the command envelope. GAUGE maintains a Bayesian command-to-motion model and selects authorized trials according to their expected reduction of posterior epistemic uncertainty under the planner-induced command distribution. The resulting posterior supports validation-based stopping, bounded inverse compensation, and task-relevant recalibration after detected interface shifts. In three controlled response families, GAUGE reaches the joint criterion for task-facing accuracy and uncertainty with fewer trials than passive, D-optimal, and task-agnostic alternatives. Across six held-out Isaac Sim navigation maps, it meets the declared noninferiority margins against dense calibration. Code is available at https://github.com/EurekaZang/CalibAgent.
Figures & tables
Fig. 1: GAUGE framework. (A) IVR, weighted by the planner-induced T , ranks untried commands in the finite pool C ; authorization selects the highest-ranked feasible command. Valid observations update the posterior. (B) The posterior supports bounded inversion. (C) Frozen μ , rj0 , and S support temporal shift detection. Recovery retains m , inflates Σ , and resumes (A) with the same T . Validation or hard budgets end calibration and recovery. All commands require authorization; the controller is fixed. Images are simulator captures.
Fig. 2: Core evidence for planner-conditioned acquisition. The independent unit is one of 20 paired seeds; the affine, dead-zone, and heteroscedastic response families are averaged within each seed. (a) Control-minus-task-IVR first-crossing trials for the joint RMSE ≤.04 and epistemic-variance ≤.0015 criterion; task IVR crosses at 18.7 trials on average. (b) Held-out task RMSE across fixed budgets, with the 24-trial acquisitions marked for the support test. (c) The same frozen 24-trial acquisitions re-evaluated under alternative command supports; positive values favor task IVR, while broad-uniform support reverses the ordering. Bands and error bars are paired 95% bootstrap intervals over seeds.
Fig. 3: Calibration and recovery under interface shifts. (a) Shift parameters; blue denotes row-normalized change magnitude. (b) Recovery dynamics; shading marks trials 4–9. (c–d) Independent early-effect and trial-12 estimates. Simulation intervals are paired 95% bootstrap intervals (30 seeds in b; 144 per shift in c–d). (e) Online calibration: bars show means; linked circles show matched commands. (f) Scheduled-hardware recovery: open circles show command contrasts, filled markers show block means, and spans show observed ranges. Positive contrasts favor GAUGE; hardware effects are descriptive.
Outcome
Count
Exact 95% interval
Worst p95 trials / s
False alarm
0/120
[0,.0303]
—
Detection
143–144/144
[.9619,.9998]
3.9 / 10.1
Recovery
141–144/144
[.9403,.9957]
9.0 / 46.8
TABLE I: Isaac Lab shift-monitor operating characteristics.
Fig. 4: Navigation after calibration. Top: overhead replays on six held-out Isaac Sim maps. Blue curves show executed trajectories; opacity increases with time. Bottom: (a) success counts; (b) raw-minus-GAUGE capped-time gain (60-s failure cap); (c) matched-budget RMSE contrasts; (d) noninferiority tests of GAUGE (12 trials) versus dense calibration (30 trials), with time-ratio and success-difference margins of 1.25 and −0.05 . Points and whiskers denote paired means and 95% bootstrap intervals over 72 seeds per map.
Fig. 5: Physical Go2 navigation records. (a–b) Long-exposure views of the route-specific GAUGE deployments on offset slalom and weighted arc. (c) A separate fixed-DRL-DCLP endurance-gait comparison in the same obstacle scene: the direct-interface rollout (left) contacts an obstacle, whereas the GAUGE-calibrated rollout (right) clears it. These physical panels are qualitative route-level records.
Digital-twin calibration requires interaction data that is expensive to collect. We study two acquisition decisions: which trajectories to generate, and when to spend a limited budget on privileged parameter measurements. Our framework couples an excitation-oriented reinforcement learning controller, a recurrent parameter estimator with predictive uncertainty, and a budgeted query policy. In Pendulum, a Random Forest diagnostic recovers gravity only weakly from task-oriented trajectories and does not recover mass or length, while a GRU trained on excitation-oriented trajectories reaches a mean absolute error of 0.0066 with no queries. We then withdraw continuous oracle access partway through an episode, so that the twin must run on the estimator's output for the remainder. The estimator-plus-policy pipeline achieves a terminal error of 0.0092 under a three-query budget, against 0.2031 for an uncalibrated twin. In partially observable Waterworld, five controllers produce different observed error profiles across three hidden parameters, and an estimator trained on a five-controller mixture reaches online normalized errors of roughly 4-5%. These exploratory case studies are not controlled ablations, but they motivate treating trajectory design and query allocation as explicit design variables in data-scarce calibration.
Vladyslava Spitkovska, Dmytro Kuzmenko
Department of Mathematics, National University of Kyiv-Mohyla Academy, Kyiv, Ukraine · Department of Multimedia Systems, National University of Kyiv-Mohyla Academy, Kyiv, Ukraine · Department of Computer Science, University of Turin, Turin, Italy
Simulation is central to robot learning, yet the sim-to-real gap remains a major bottleneck. Existing approaches often tackle visual or dynamic gaps separately, overlooking how these individual mismatches accumulate and propagate throughout the robot's state evolution. In this paper, we introduce QuadVerse, an integrated framework that uses reconstructed scenes as a calibration substrate for aligning visual perception, physical interaction, and actuator dynamics. From captured RGB videos, we reconstruct geometry-constrained 3D Gaussian Splatting (3DGS) scenes that support batched photorealistic ego-view rendering and collision-ready semantic mesh extraction. The meshes further enable contact calibration by initializing spatially varying friction priors and refining them through trajectory-based posterior search. To address remaining actuator discrepancies, QuadVerse trains a residual dynamics compensator by replaying real-world trajectories on the contact-calibrated terrain, reducing the entanglement between terrain-induced contact errors and actuator non-idealities. Experiments show that QuadVerse improves reconstruction quality and locomotion tracking over relevant baselines. Leveraging this foundation, we demonstrate robust zero-shot visual-navigation policy deployment without task-specific real-world rollouts.
Agile quadruped navigation in dynamic environments demands trajectories that are both dynamically feasible and provably collision-free. Most real-time planners achieve tractability through a convex reduction that requires simplified kinematic models, discarding motion that the robot can readily execute, and certify safety only at discretization points, leaving open possible inter-sample collisions with moving obstacles. We present a real-time motion planning framework that retains the fully-actuated SE(2) model of a quadruped, with its anisotropic, heading-coupled velocity bounds, and accepts the resulting nonconvexity. By parameterizing trajectories as composite Bernstein polynomials, we exploit the convex hull property to certify collision avoidance and the input bounds over the entirety of each planning horizon. Solved at online replanning rates, the optimization runs in closed loop, commanding body velocities to the locomotion controller. We validate the approach in simulation against ablations and external baselines, and in hardware experiments on a quadruped navigating among unknown moving obstacles, recovering both lateral and heading-coupled motion that simplified models exclude.
Gage MacLin, Mason Peterson, Camilla Tabasso +4
Amazon Fulfillment Technologies & Robotics, Westborough MA, USA. · University of Iowa, Iowa City, IA 52240. · Massachusetts Institute of Technology, Cambridge, MA 02139, USA.