Search Results for author: Ian R. Manchester

Found 32 papers, 10 papers with code

Learning Stable and Passive Neural Differential Equations

1 code implementation19 Apr 2024 Jing Cheng, Ruigang Wang, Ian R. Manchester

We take a recently proposed Polyak Lojasiewicz network (PLNet) as an Lyapunov function and then parameterize the vector field as the descent directions of the Lyapunov function.

Control contraction metrics on Lie groups

no code implementations22 Mar 2024 Dongjun Wu, Bowen Yi, Ian R. Manchester

The results extend the applicability of the CCM approach and provide a framework for analyzing the behavior of control systems with Lie group structures.

Monotone, Bi-Lipschitz, and Polyak-Lojasiewicz Networks

no code implementations2 Feb 2024 Ruigang Wang, Krishnamurthy Dvijotham, Ian R. Manchester

This paper presents a new \emph{bi-Lipschitz} invertible neural network, the BiLipNet, which has the ability to control both its \emph{Lipschitzness} (output sensitivity to input perturbations) and \emph{inverse Lipschitzness} (input distinguishability from different outputs).

Learning Stable Koopman Embeddings for Identification and Control

no code implementations16 Jan 2024 Fletcher Fan, Bowen Yi, David Rye, Guodong Shi, Ian R. Manchester

Whereas most existing works on Koopman learning do not take into account the stability or stabilizability of the model -- two fundamental pieces of prior knowledge about a given system to be identified -- in this paper, we propose new classes of Koopman models that have built-in guarantees of these properties.

Imitation Learning

On IMU preintegration: A nonlinear observer viewpoint and its application

no code implementations9 Jul 2023 Bowen Yi, Ian R. Manchester

The inertial measurement unit (IMU) preintegration approach nowadays is widely used in various robotic applications.

PEBO-SLAM: Observer design for visual inertial SLAM with convergence guarantees

no code implementations22 Jun 2023 Bowen Yi, Chi Jin, Lei Wang, Guodong Shi, Viorela Ila, Ian R. Manchester

This paper introduces a new linear parameterization to the problem of visual inertial simultaneous localization and mapping (VI-SLAM) -- without any approximation -- for the case only using information from a single monocular camera and an inertial measurement unit.

Simultaneous Localization and Mapping

Learning Over Contracting and Lipschitz Closed-Loops for Partially-Observed Nonlinear Systems (Extended Version)

1 code implementation12 Apr 2023 Nicholas H. Barbara, Ruigang Wang, Ian R. Manchester

This paper presents a policy parameterization for learning-based control on nonlinear, partially-observed dynamical systems.

Unconstrained Parametrization of Dissipative and Contracting Neural Ordinary Differential Equations

1 code implementation6 Apr 2023 Daniele Martinelli, Clara Lucía Galimberti, Ian R. Manchester, Luca Furieri, Giancarlo Ferrari-Trecate

We validate the properties of NodeRENs, including the possibility of handling irregularly sampled data, in a case study in nonlinear system identification.

Lipschitz-bounded 1D convolutional neural networks using the Cayley transform and the controllability Gramian

1 code implementation20 Mar 2023 Patricia Pauli, Ruigang Wang, Ian R. Manchester, Frank Allgöwer

We establish a layer-wise parameterization for 1D convolutional neural networks (CNNs) with built-in end-to-end robustness guarantees.

Sparse Resource Allocation for Spreading Processes on Temporal-Switching Networks

no code implementations4 Feb 2023 Vera L. J. Somers, Ian R. Manchester

Spreading processes, e. g. epidemics, wildfires and rumors, are often modeled on static networks.

Misinformation

Direct Parameterization of Lipschitz-Bounded Deep Networks

2 code implementations27 Jan 2023 Ruigang Wang, Ian R. Manchester

This paper introduces a new parameterization of deep neural networks (both fully-connected and convolutional) with guaranteed $\ell^2$ Lipschitz bounds, i. e. limited sensitivity to input perturbations.

Image Classification

Attitude estimation from vector measurements: Necessary and sufficient conditions and convergent observer design

no code implementations27 Jun 2022 Bowen Yi, Lei Wang, Ian R. Manchester

The paper addresses the problem of attitude estimation for rigid bodies using (possibly time-varying) vector measurements, for which we provide a necessary and sufficient condition of distinguishability.

Globally convergent visual-feature range estimation with biased inertial measurements

no code implementations23 Dec 2021 Bowen Yi, Chi Jin, Ian R. Manchester

The design of a globally convergent position observer for feature points from visual information is a challenging problem, especially for the case with only inertial measurements and without assumptions of uniform observability, which remained open for a long time.

Learning over All Stabilizing Nonlinear Controllers for a Partially-Observed Linear System

no code implementations8 Dec 2021 Ruigang Wang, Nicholas H. Barbara, Max Revay, Ian R. Manchester

This paper proposes a nonlinear policy architecture for control of partially-observed linear dynamical systems providing built-in closed-loop stability guarantees.

Reinforcement Learning (RL)

Youla-REN: Learning Nonlinear Feedback Policies with Robust Stability Guarantees

no code implementations2 Dec 2021 Ruigang Wang, Ian R. Manchester

This paper presents a parameterization of nonlinear controllers for uncertain systems building on a recently developed neural network architecture, called the recurrent equilibrium network (REN), and a nonlinear version of the Youla parameterization.

Multi-Stage Sparse Resource Allocation for Control of Spreading Processes over Networks

no code implementations14 Oct 2021 Vera L. J. Somers, Ian R. Manchester

In this paper we propose a method for sparse dynamic allocation of resources to bound the risk of spreading processes, such as epidemics and wildfires, using convex optimization and dynamic programming techniques.

Learning Stable Koopman Embeddings

1 code implementation13 Oct 2021 Fletcher Fan, Bowen Yi, David Rye, Guodong Shi, Ian R. Manchester

In this paper, we present a new data-driven method for learning stable models of nonlinear systems.

Contraction-Based Methods for Stable Identification and Robust Machine Learning: a Tutorial

no code implementations1 Oct 2021 Ian R. Manchester, Max Revay, Ruigang Wang

This tutorial paper provides an introduction to recently developed tools for machine learning, especially learning dynamical systems (system identification), with stability and robustness constraints.

BIG-bench Machine Learning

Distributed Identification of Contracting and/or Monotone Network Dynamics

no code implementations29 Jul 2021 Max Revay, Jack Umenberger, Ian R. Manchester

This paper proposes methods for identification of large-scale networked systems with guarantees that the resulting model will be contracting -- a strong form of nonlinear stability -- and/or monotone, i. e. order relations between states are preserved.

Minimizing the Risk of Spreading Processes via Surveillance Schedules and Sparse Control

no code implementations13 Jul 2021 Vera L. J. Somers, Ian R. Manchester

Here, risk is considered the risk of an undetected outbreak, i. e. the product of the probability of an outbreak and the impact of that outbreak, and we can bound or minimize the risk by resource allocation and persistent monitoring schedules.

Recurrent Equilibrium Networks: Flexible Dynamic Models with Guaranteed Stability and Robustness

1 code implementation13 Apr 2021 Max Revay, Ruigang Wang, Ian R. Manchester

RENs are otherwise very flexible: they can represent all stable linear systems, all previously-known sets of contracting recurrent neural networks and echo state networks, all deep feedforward neural networks, and all stable Wiener/Hammerstein models, and can approximate all fading-memory and contracting nonlinear systems.

Nonlinear parameter-varying state-feedback design for a gyroscope using virtual control contraction metrics

no code implementations11 Apr 2021 Ruigang Wang, Patrick J. W. Koelwijn, Ian R. Manchester, Roland Tóth

In this paper, we present a virtual control contraction metric (VCCM) based nonlinear parameter-varying (NPV) approach to design a state-feedback controller for a control moment gyroscope (CMG) to track a user-defined trajectory set.

Lipschitz Bounded Equilibrium Networks

no code implementations5 Oct 2020 Max Revay, Ruigang Wang, Ian R. Manchester

In image classification experiments we show that the Lipschitz bounds are very accurate and improve robustness to adversarial attacks.

Generalization Bounds Image Classification

A Convex Parameterization of Robust Recurrent Neural Networks

no code implementations11 Apr 2020 Max Revay, Ruigang Wang, Ian R. Manchester

Recurrent neural networks (RNNs) are a class of nonlinear dynamical systems often used to model sequence-to-sequence maps.

Virtual Control Contraction Metrics: Convex Nonlinear Feedback Design via Behavioral Embedding

no code implementations18 Mar 2020 Ruigang Wang, Roland Tóth, Patrick J. W. Koelwijn, Ian R. Manchester

This paper presents a systematic approach to nonlinear state-feedback control design that has three main advantages: (i) it ensures exponential stability and $ \mathcal{L}_2 $-gain performance with respect to a user-defined set of reference trajectories, and (ii) it provides constructive conditions based on convex optimization and a path-integral-based control realization, and (iii) it is less restrictive than previous similar approaches.

Sparse Resource Allocation for Control of Spreading Processes via Convex Optimization

1 code implementation17 Mar 2020 Vera L. J. Somers, Ian R. Manchester

In this letter we propose a method for sparse allocation of resources to control spreading processes -- such as epidemics and wildfires -- using convex optimization, in particular exponential cone programming.

Systems and Control Systems and Control Dynamical Systems Optimization and Control

Contracting Implicit Recurrent Neural Networks: Stable Models with Improved Trainability

1 code implementation L4DC 2020 Max Revay, Ian R. Manchester

Stability of recurrent models is closely linked with trainability, generalizability and in some applications, safety.

Specialized Interior Point Algorithm for Stable Nonlinear System Identification

no code implementations2 Mar 2018 Jack Umenberger, Ian R. Manchester

Estimation of nonlinear dynamic models from data poses many challenges, including model instability and non-convexity of long-term simulation fidelity.

Contracting Nonlinear Observers: Convex Optimization and Learning from Data

no code implementations22 Nov 2017 Ian R. Manchester

A new approach to design of nonlinear observers (state estimators) is proposed.

Convex Parameterizations and Fidelity Bounds for Nonlinear Identification and Reduced-Order Modelling

no code implementations23 Jan 2017 Mark M. Tobenkin, Ian R. Manchester, Alexandre Megretski

Model instability and poor prediction of long-term behavior are common problems when modeling dynamical systems using nonlinear "black-box" techniques.

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