arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2002.07870cs.ROcs.LG
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高斯过程安全临界系统的在线参数估计

Online Parameter Estimation for Safety-Critical Systems with Gaussian Processes

Georgia Institute of Technology(佐治亚理工学院)

Mouhyemen Khan, Abhijit Chatterjee

摘要:

参数估计对于复杂动态系统的建模、跟踪和控制至关重要。然而,参数的不确定性会损害系统性能的控制器依赖于标称参数值。通常,参数估计使用数值回归方法作为反问题。然而,由于存在多个局部最优解、依赖梯度、大量实验数据或稳定性问题,它们具有非唯一性。针对这些缺点,我们提出了一个贝叶斯优化框架的基础上高斯过程(GP)的在线参数估计。它使用一个有效的搜索策略在参数空间的响应面上找到全局最优值与最小的功能评估。响应面被建模为相关的代理人使用GPS噪声数据。GP后验预测方差用于智能自适应采样。这平衡了探索与开发的权衡,这是在有限预算下达到全局最优的关键。我们证明了我们的技术驱动平面摆和安全关键的四旋翼在模拟与变化的参数。我们还基准我们的结果对求解器使用内点法和序列二次规划。通过重新配置控制器与新的优化参数迭代,我们大大提高了系统的轨迹跟踪与标称情况下和其他求解器。

英文摘要:

Parameter estimation is crucial for modeling, tracking, and control of complex dynamical systems. However, parameter uncertainties can compromise system performance under a controller relying on nominal parameter values. Typically, parameters are estimated using numerical regression approaches framed as inverse problems. However, they suffer from non-uniqueness due to existence of multiple local optima, reliance on gradients, numerous experimental data, or stability issues. Addressing these drawbacks, we present a Bayesian optimization framework based on Gaussian processes (GPs) for online parameter estimation. It uses an efficient search strategy over a response surface in the parameter space for finding the global optima with minimal function evaluations. The response surface is modeled as correlated surrogates using GPs on noisy data. The GP posterior predictive variance is exploited for smart adaptive sampling. This balances the exploration versus exploitation trade-off which is key in reaching the global optima under limited budget. We demonstrate our technique on an actuated planar pendulum and safety-critical quadrotor in simulation with changing parameters. We also benchmark our results against solvers using interior point method and sequential quadratic program. By reconfiguring the controller with new optimized parameters iteratively, we drastically improve trajectory tracking of the system versus the nominal case and other solvers.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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