Reachability-Based Safety Guarantees using Efficient Initializations
Reachability-Based Safety Guarantees using Efficient Initializations
复制标题
使用高效初始化的基于可达性的安全保证
DOI：
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
C. Tomlin
中科院分区：
文献类型：
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作者：
Sylvia L. Herbert;Shromona Ghosh;Somil Bansal;C. Tomlin
Hamilton Jacobi Isaacs（HJI）可达性分析是分析自治系统安全性的有力工具。这种分析是计算密集型的，并且通常离线执行。然而，在线时，自主系统可能会经历系统动态、外部干扰和/或周围环境的变化，需要更新的安全保证。而不是重新开始的安全分析，我们提出了一种方法的“热启动”的可达性，它使用用户定义的初始化（通常是以前计算的解决方案）。通过从比标准初始化更接近解的HJI函数开始，分析可以进行更少的迭代。在本文中，我们证明，热启动将导致保证保守的解决方案，通过过度近似的状态，必须避免保持安全。我们还证明，对于许多常见的问题配方，热启动将导致精确的解决方案。我们用双积分器在几个说明性的例子上演示了我们的方法，并且还用一个更实用的10维四轴飞行器模型来演示，该模型经历了质量和干扰的变化，并且必须相应地更新其安全保证。我们比较我们的方法，标准的可达性和最近提出的“折扣”的可达性方法，并发现我们的例子，热启动是1：6倍快于标准和6：2倍快于（未调整）折扣的可达性。
Hamilton-Jacobi-Isaacs (HJI) reachability analysis is a powerful tool for analyzing the safety of autonomous systems. This analysis is computationally intensive and typically performed offline. Online, however, the autonomous system may experience changes in system dynamics, external disturbances, and/or the surrounding environment, requiring updated safety guarantees. Rather than restarting the safety analysis, we propose a method of "warm-start" reachability, which uses a user-defined initialization (typically the previously computed solution). By starting with an HJI function that is closer to the solution than the standard initialization, the analysis may take fewer iterations. In this paper we prove that warm-starting will result in guaranteed conservative solutions by over-approximating the states that must be avoided to maintain safety. We additionally prove that for many common problem formulations, warm-starting will result in exact solutions. We demonstrate our method on several illustrative examples with a double integrator, and also with a more practical 10D quadcopter model that experiences changes in mass and disturbances and must update its safety guarantees accordingly. We compare our approach to standard reachability and a recently proposed "discounted" reachability method, and find for our examples that warm-starting is 1:6 times faster than standard and 6:2 times faster than (untuned) discounted reachability.
可达性分析作为雨水系统的设计工具
DOI：
10.1109/sustech.2018.8671362
发表时间：
2018
期刊：
2018 IEEE Conference on Technologies for Sustainability (SusTech
影响因子：
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作者：
Chapman, Margaret P.;Smith, Kevin M.;Cheng, Victoria;Freyberg, David L.;Tomlin, Claire J.
通讯作者：
Tomlin, Claire J.