让双足机器人在不确定地形上安全行走,给出可验证的安全保障。
Probabilistically-Safe Bipedal Navigation over Uncertain Terrain via Conformal Prediction and Contraction Analysis
- 用高斯过程和置信预测构建地形高度的可信区间
- 通过收缩分析确保机器人质心轨迹稳定且不偏离安全区域
- 适合需要高可靠性行走控制的机器人研发人员
本文针对双足机器人在崎岖地形上行进的挑战,提出一种概率安全的规划与控制策略,确保动态可行性与质心鲁棒性。通过高阶模型预测控制(MPC)框架,在给定置信水平下实现向目标位置的安全穿越,同时将地形不确定性显式纳入质心动力学建模。采用高斯过程回归估计地形高程图,并利用置信预测(CP)生成校准的置信区间以捕捉真实地形高程。在此基础上,构建基于收缩理论的可达管,明确考虑地形不确定性,保证状态收敛与管路不变性。此外,提出基于收缩理论的飞轮力矩控制律,应用于简化版线性倒立摆模型(LIPM),稳定质心角动量。该方法提供概率安全性和目标可达性双重保证。在给定置信水平下,证明了实际质心相空间轨迹与高层规划轨迹之间的指数稳定,从而确保前向不变性。最后,通过在MuJoCo中对Digit双足机器人进行物理仿真验证了该框架的有效性。
原文摘要 · Abstract (English)
We address the challenge of enabling bipedal robots to traverse rough terrain by developing probabilistically safe planning and control strategies that ensure dynamic feasibility and centroidal robustness under terrain uncertainty. Specifically, we propose a high-level Model Predictive Control (MPC) navigation framework for a bipedal robot with a specified confidence level of safety that (i) enables safe traversal toward a desired goal location across a terrain map with uncertain elevations, and (ii) formally incorporates uncertainty bounds into the centroidal dynamics of locomotion control. To model the rough terrain, we employ Gaussian Process (GP) regression to estimate elevation maps and leverage Conformal Prediction (CP) to construct calibrated confidence intervals that capture the true terrain elevation. Building on this, we formulate contraction-based reachable tubes that explicitly account for terrain uncertainty, ensuring state convergence and tube invariance. In addition, we introduce a contraction-based flywheel torque control law for the reduced-order Linear Inverted Pendulum Model (LIPM), which stabilizes the angular momentum about the center-of-mass (CoM). This formulation provides both probabilistic safety and goal reachability guarantees. For a given confidence level, we establish the forward invariance of the proposed torque control law by demonstrating exponential stabilization of the actual CoM phase-space trajectory and the desired trajectory prescribed by the high-level planner. Finally, we evaluate the effectiveness of our planning framework through physics-based simulations of the Digit bipedal robot in MuJoCo.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。