robust control
- Europe > Sweden > Uppsala County > Uppsala (0.04)
- Asia > Middle East > Jordan (0.04)
- North America > United States > New Jersey (0.04)
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Ignorance is Bliss: Robust Control via Information Gating
Informational parsimony provides a useful inductive bias for learning representations that achieve better generalization by being robust to noise and spurious correlations. We propose as a way to learn parsimonious representations that identify the minimal information required for a task. When gating information, we can learn to reveal as little information as possible so that a task remains solvable, or hide as little information as possible so that a task becomes unsolvable. We gate information using a differentiable parameterization of the signal-to-noise ratio, which can be applied to arbitrary values in a network, e.g., erasing pixels at the input layer or activations in some intermediate layer. When gating at the input layer, our models learn which visual cues matter for a given task.
Global Convergence of Direct Policy Search for State-Feedback \mathcal{H}_\infty Robust Control: A Revisit of Nonsmooth Synthesis with Goldstein Subdifferential
Direct policy search has been widely applied in modern reinforcement learning and continuous control. However, the theoretical properties of direct policy search on nonsmooth robust control synthesis have not been fully understood. The optimal $\mathcal{H}_\infty$ control framework aims at designing a policy to minimize the closed-loop $\mathcal{H}_\infty$ norm, and is arguably the most fundamental robust control paradigm. In this work, we show that direct policy search is guaranteed to find the global solution of the robust $\mathcal{H}_\infty$ state-feedback control design problem. Notice that policy search for optimal $\mathcal{H}_\infty$ control leads to a constrained nonconvex nonsmooth optimization problem, where the nonconvex feasible set consists of all the policies stabilizing the closed-loop dynamics. We show that for this nonsmooth optimization problem, all Clarke stationary points are global minimum. Next, we identify the coerciveness of the closed-loop $\mathcal{H}_\infty$ objective function, and prove that all the sublevel sets of the resultant policy search problem are compact. Based on these properties, we show that Goldstein's subgradient method and its implementable variants can be guaranteed to stay in the nonconvex feasible set and eventually find the global optimal solution of the $\mathcal{H}_\infty$ state-feedback synthesis problem. Our work builds a new connection between nonconvex nonsmooth optimization theory and robust control, leading to an interesting global convergence result for direct policy search on optimal $\mathcal{H}_\infty$ synthesis.
- Europe > Sweden > Uppsala County > Uppsala (0.04)
- Asia > Middle East > Jordan (0.04)
- North America > United States > New Jersey (0.04)
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Rev 1
We thank the reviewer for the positive feedback. RARL to each local linear model and then use the idea in guided policy search to piece together all local controllers. One issue is that there will not be a "global" robustness guarantee. But our results still hold locally. However, these methods can hardly be made "model-free", and are less scalable (to high dim.
Full-Pose Tracking via Robust Control for Over-Actuated Multirotors
Hachem, Mohamad, Roos, Clément, Miquel, Thierry, Bronz, Murat
This paper presents a robust cascaded control architecture for over-actuated multirotors. It extends the Incremental Nonlinear Dynamic Inversion (INDI) control combined with structured H_inf control, initially proposed for under-actuated multirotors, to a broader range of multirotor configurations. To achieve precise and robust attitude and position tracking, we employ a weighted least-squares geometric guidance control allocation method, formulated as a quadratic optimization problem, enabling full-pose tracking. The proposed approach effectively addresses key challenges, such as preventing infeasible pose references and enhancing robustness against disturbances, as well as considering multirotor's actual physical limitations. Numerical simulations with an over-actuated hexacopter validate the method's effectiveness, demonstrating its adaptability to diverse mission scenarios and its potential for real-world aerial applications.
- Europe > France > Occitanie > Haute-Garonne > Toulouse (0.05)
- North America > United States > Pennsylvania > Philadelphia County > Philadelphia (0.04)
- North America > United States > Nevada > Clark County > Las Vegas (0.04)
- (3 more...)
Ignorance is Bliss: Robust Control via Information Gating
Informational parsimony provides a useful inductive bias for learning representations that achieve better generalization by being robust to noise and spurious correlations. We propose information gating as a way to learn parsimonious representations that identify the minimal information required for a task. When gating information, we can learn to reveal as little information as possible so that a task remains solvable, or hide as little information as possible so that a task becomes unsolvable. We gate information using a differentiable parameterization of the signal-to-noise ratio, which can be applied to arbitrary values in a network, e.g., erasing pixels at the input layer or activations in some intermediate layer. When gating at the input layer, our models learn which visual cues matter for a given task.
Ignorance is Bliss: Robust Control via Information Gating
Informational parsimony provides a useful inductive bias for learning representations that achieve better generalization by being robust to noise and spurious correlations. We propose information gating as a way to learn parsimonious representations that identify the minimal information required for a task. When gating information, we can learn to reveal as little information as possible so that a task remains solvable, or hide as little information as possible so that a task becomes unsolvable. We gate information using a differentiable parameterization of the signal-to-noise ratio, which can be applied to arbitrary values in a network, e.g., erasing pixels at the input layer or activations in some intermediate layer. When gating at the input layer, our models learn which visual cues matter for a given task.
Continuous-Time Robust Control for Cancer Treatment Robots
Mihaly, Vlad, Birlescu, Iosif, Şuşcă, Mircea, Chablat, Damien, Dobra, Petru
The control system in surgical robots must ensure patient safety and real time control. As such, all the uncertainties which could appear should be considered into an extended model of the plant. After such an uncertain plant is formed, an adequate controller which ensures a minimum set of performances for each situation should be computed. As such, the continuous-time robust control paradigm is suitable for such scenarios. However, the problem is generally solved only for linear and time invariant plants. The main focus of the current paper is to include m-link serial surgical robots into Robust Control Framework by considering all nonlinearities as uncertainties.
- Europe > France > Pays de la Loire > Loire-Atlantique > Nantes (0.05)
- Europe > Romania > Nord-Vest Development Region > Cluj County > Cluj-Napoca (0.05)
- North America > United States > New Jersey > Hudson County > Hoboken (0.04)
- Europe > Germany (0.04)
- Health & Medicine > Therapeutic Area > Oncology (0.86)
- Health & Medicine > Pharmaceuticals & Biotechnology (0.86)
Unveiling LLM Mechanisms Through Neural ODEs and Control Theory
This study presents a novel approach that leverages Neural Ordinary Differential Equations (Neural ODEs) to unravel the intricate relationships between inputs and outputs in Large Language Models (LLMs), and employs robust control to fine-tune outputs to meet predefined standards. Central to our methodology is the transformation of LLM inputs and outputs into a lower-dimensional latent space, facilitating a detailed examination of the information processing pathways within LLMs. Neural ODEs play a pivotal role in this investigation by providing a dynamic model that captures the continuous evolution of data within the LLMs. Additionally, robust control mechanisms are applied to strategically adjust the model's outputs, ensuring they not only maintain high quality and reliability but also adhere to specific performance criteria. This fusion of Neural ODEs and robust control represents a significant advancement in LLM interpretability, offering a comprehensive framework that elucidates the previously opaque mechanisms of these complex models. Our empirical results validate the effectiveness of this integrated approach, making a substantial contribution to the field of explainable AI by merging advanced machine learning techniques with the critical need for transparency and control in AI outputs.
- Research Report > New Finding (0.68)
- Research Report > Promising Solution (0.48)