论文标题
从全球角度重新思考优化，并通过可区分的仿真进行优化
Rethinking Optimization with Differentiable Simulation from a Global Perspective
论文作者
论文摘要
可区分的仿真是用于基于快速梯度的策略优化和系统识别的有前途的工具包。但是，现有的可区分仿真方法在很大程度上已经解决了获得平滑梯度相对容易的方案，例如具有光滑动力学的系统。在这项工作中，我们研究了可区分仿真所面临的挑战，当时单个下降是不可行的，这通常是全球最佳的，这通常是接触率丰富的方案中的问题。我们分析包含刚体和可变形物体的各种情况的优化景观。在具有高度可变形的物体和流体的动态环境中，可区分的模拟器在空间的某些地方生产具有有用梯度的坚固景观。我们提出了一种将贝叶斯优化与半本地“飞跃”相结合的方法，以获得可以有效使用梯度的全局搜索方法，同时还可以在具有嘈杂梯度的地区保持稳健的性能。我们表明，我们的方法在一组模拟中的广泛实验集上优于基于梯度的几个基准，并且使用具有真实机器人和变形物的实验验证该方法。视频和补充材料可在https://tinyurl.com/globdiff上获得
Differentiable simulation is a promising toolkit for fast gradient-based policy optimization and system identification. However, existing approaches to differentiable simulation have largely tackled scenarios where obtaining smooth gradients has been relatively easy, such as systems with mostly smooth dynamics. In this work, we study the challenges that differentiable simulation presents when it is not feasible to expect that a single descent reaches a global optimum, which is often a problem in contact-rich scenarios. We analyze the optimization landscapes of diverse scenarios that contain both rigid bodies and deformable objects. In dynamic environments with highly deformable objects and fluids, differentiable simulators produce rugged landscapes with nonetheless useful gradients in some parts of the space. We propose a method that combines Bayesian optimization with semi-local 'leaps' to obtain a global search method that can use gradients effectively, while also maintaining robust performance in regions with noisy gradients. We show that our approach outperforms several gradient-based and gradient-free baselines on an extensive set of experiments in simulation, and also validate the method using experiments with a real robot and deformables. Videos and supplementary materials are available at https://tinyurl.com/globdiff
