提出可微且高效并行的接触流形构造方法,提升机器人接触场景模拟的计算效率。
Novel Algorithms for Smoothly Differentiable and Efficiently Vectorizable Contact Manifold Construction

- 从头设计可微分的碰撞检测流程,支持二阶导数计算
- 采用高效SDF表示与可微分接触生成,实现大规模并行化
- 适用于需梯度优化的机器人动力学仿真,尤其适合GPU加速
在高接触密度的机器人行为生成中,当前主要依赖零阶方法。利用刚体动力学中的一阶、二阶信息有望显著提升求解速度与计算效率。然而,其核心瓶颈在于模拟流程中三阶段(碰撞检测、接触动力学、时间积分)均存在导致梯度与海森矩阵难以获取的病态问题。本文聚焦于碰撞检测环节,提出一种全新设计的可微分、高度可向量化管道,以双可微性与GPU大规模并行作为首要目标。相较传统基于CPU优化、内存占用小但逻辑复杂、控制流多的碰撞检测方案,本方法具有更强的可微性与并行潜力。具体贡献包括:i) 高表达力且计算高效的SDF表示;ii) 基于该表示的可微分宽相与窄相接触检测,生成顶点-SDF与边-SDF接触;iii) 基于凸分解的可微分接触融合算法。
原文摘要 · Abstract (English)
Generating intelligent robot behavior in contact-rich settings is a research problem where zeroth-order methods currently prevail. Developing methods that make use of first/second order information about rigid-body dynamics in the presence of contact holds great promise in terms of increasing the solution speed and computational efficiency. The main bottleneck in this research direction is the difficulty in obtaining gradients and Hessians that are actually useful for numerical optimization, due to pathologies in all three steps of a common simulation pipeline: i) collision detection, ii) contact dynamics, iii) time integration. This abstract proposes a method that aims to address the collision detection part of the puzzle, via a novel pipeline designed from scratch with smooth (i.e. twice) differentiability and massive vectorizability on GPUs as the main priorities. This is in contrast to standard collision detection routines that are instead optimized for runtime on CPUs and minimal memory footprint, but do employ logic and control flow that hinder differentiability and vectorization. The proposed pipeline consists of the following contributions: i) highly expressive and compute efficient SDF representations, ii) differentiable broad-phase and narrow-phase routines that use these representations to generate vertex-SDF and edge-SDF contacts, iii) a differentiable routine for convex decomposition based contact blending.
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。