no code implementations • 27 Mar 2024 • Sebastian Schlor, Frank Allgöwer
By recognizing the bootstrapping errors occurring in the controller's state as an uncertainty in the robust control framework, we can provide stability and performance guarantees for the whole encrypted control system.
no code implementations • 22 Mar 2024 • Robin Strässer, Marc Seidel, Felix Brändle, David Meister, Raffaele Soloperto, David Hambach Ferrer, Frank Allgöwer
In this paper, we propose a collision avoidance safety filter for autonomous electric scooters to enable safe operation of such vehicles in pedestrian areas.
no code implementations • 5 Feb 2024 • Robin Strässer, Manuel Schaller, Karl Worthmann, Julian Berberich, Frank Allgöwer
The Koopman operator serves as the theoretical backbone for machine learning of dynamical control systems, where the operator is heuristically approximated by extended dynamic mode decomposition (EDMD).
no code implementations • 25 Jan 2024 • Patricia Pauli, Aaron Havens, Alexandre Araujo, Siddharth Garg, Farshad Khorrami, Frank Allgöwer, Bin Hu
However, a direct application of LipSDP to the resultant residual ReLU networks is conservative and even fails in recovering the well-known fact that the MaxMin activation is 1-Lipschitz.
no code implementations • 10 Dec 2023 • Janani Venkatasubramanian, Johannes Köhler, Mark Cannon, Frank Allgöwer
We present a novel targeted exploration strategy for linear time-invariant systems without stochastic assumptions on the noise, i. e., without requiring independence or zero mean, allowing for deterministic model misspecifications.
no code implementations • 3 Dec 2023 • Robin Strässer, Manuel Schaller, Karl Worthmann, Julian Berberich, Frank Allgöwer
We present a method to design a state-feedback controller ensuring exponential stability for nonlinear systems using only measurement data.
no code implementations • 21 Nov 2023 • Robin Strässer, Sebastian Schlor, Frank Allgöwer
Our results on the required lifting dimension are in line with the intractability of brute-force attacks.
no code implementations • 7 Sep 2023 • David Meister, Frank Allgöwer
We therefore demonstrate that the performance degradation found in the distributed setting originates from the triggering rule and not from the considered cooperative control goal.
no code implementations • 6 Jul 2023 • Johannes Köhler, Matthas A. Müller, Frank Allgöwer
This article provides an overview of model predictive control (MPC) frameworks for dynamic operation of nonlinear constrained systems.
no code implementations • 13 May 2023 • Marc Seidel, Simon Lang, Frank Allgöwer
This paper considers control systems with failures in the feedback channel, that occasionally lead to loss of the control input signal.
no code implementations • 14 Apr 2023 • Henning Schlüter, Frank Allgöwer
We present a Stochastic Model Predictive Control (SMPC) framework for linear systems subject to Gaussian disturbances.
no code implementations • 10 Apr 2023 • Robin Strässer, Julian Berberich, Frank Allgöwer
In this paper, we present a state-feedback controller design method for bilinear systems.
no code implementations • 7 Apr 2023 • Robin Strässer, Julian Berberich, Frank Allgöwer
Data-driven analysis and control of dynamical systems have gained a lot of interest in recent years.
no code implementations • 6 Apr 2023 • Matthias Köhler, Matthias A. Müller, Frank Allgöwer
We show that under suitable assumptions, the agents can incrementally move their artificial output trajectories towards the cooperative goal, and, hence, their closed-loop output trajectories asymptotically achieve it.
no code implementations • 22 Mar 2023 • Michael Hertneck, Frank Allgöwer
Most approaches for self-triggered control (STC) of nonlinear networked control systems (NCS) require measurements of the full system state to determine transmission times.
no code implementations • 20 Mar 2023 • David Meister, Frank Aurzada, Mikhail A. Lifshits, Frank Allgöwer
Inspired by existing performance analyses for the single-loop case, we provide a first fundamental performance comparison of time- and event-triggered control in a distributed multi-agent consensus setting.
1 code implementation • 20 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.
no code implementations • 17 Mar 2023 • Chris Verhoek, Julian Berberich, Sofie Haesaert, Frank Allgöwer, Roland Tóth
We derive direct data-driven dissipativity analysis methods for Linear Parameter-Varying (LPV) systems using a single sequence of input-scheduling-output data.
no code implementations • 6 Mar 2023 • Dennis Gramlich, Patricia Pauli, Carsten W. Scherer, Frank Allgöwer, Christian Ebenbauer
This paper introduces a novel representation of convolutional Neural Networks (CNNs) in terms of 2-D dynamical systems.
no code implementations • 19 Jan 2023 • Janani Venkatasubramanian, Johannes Köhler, Julian Berberich, Frank Allgöwer
This provides an a priori upper bound on the remaining model uncertainty after exploration, which can further be leveraged in a gain-scheduling controller design that guarantees robust performance.
no code implementations • 2 Dec 2022 • Yifan Xie, Julian Berberich, Frank Allgöwer
By employing a generalized terminal constraint with artificial equilibrium, the scheme does not require prior knowledge of the optimal equilibrium.
no code implementations • 28 Nov 2022 • Patricia Pauli, Dennis Gramlich, Frank Allgöwer
In this work, we propose a dissipativity-based method for Lipschitz constant estimation of 1D convolutional neural networks (CNNs).
no code implementations • 21 Nov 2022 • Sebastian Schlor, Robin Strässer, Frank Allgöwer
In this paper, we introduce a new perspective on cryptosystems by interpreting the Diffie-Hellman key exchange as a nonlinear dynamical system.
no code implementations • 17 Nov 2022 • Lukas Schwenkel, Johannes Köhler, Matthias A. Müller, Frank Allgöwer
This work provides a framework to compute an upper bound on the robust peak-to-peak gain of discrete-time uncertain linear systems using integral quadratic constraints (IQCs).
no code implementations • 15 Nov 2022 • David Meister, Frank Dürr, Frank Allgöwer
While this motivation is commonly used also for multi-agent systems, a theoretical analysis of the impact of network effects on the performance of event- and time-triggered control for such distributed systems is currently missing.
no code implementations • 11 Nov 2022 • Mohammad Alsalti, Victor G. Lopez, Julian Berberich, Frank Allgöwer, Matthias A. Müller
We present a data-driven nonlinear predictive control approach for the class of discrete-time multi-input multi-output feedback linearizable nonlinear systems.
no code implementations • 18 Oct 2022 • Matthias Köhler, Matthias A. Müller, Frank Allgöwer
We present a sequential distributed model predictive control (MPC) scheme for cooperative control of multi-agent systems with dynamically decoupled heterogeneous nonlinear agents subject to individual constraints.
no code implementations • 22 Aug 2022 • Xin Wang, Jian Sun, Gang Wang, Frank Allgöwer, Jie Chen
The present paper deals with data-driven event-triggered control of a class of unknown discrete-time interconnected systems (a. k. a.
no code implementations • 17 Jun 2022 • David Meister, Frank Aurzada, Mikhail A. Lifshits, Frank Allgöwer
Contrary to the non-cooperative setting, we prove that event-triggered control performs worse than time-triggered control beyond a certain number of agents in this setup.
no code implementations • 24 May 2022 • Julian Berberich, Johannes Köhler, Matthias A. Müller, Frank Allgöwer
Moreover, we discuss how the presented proof technique allows to show closed-loop stability of a variety of DD-MPC schemes with noisy data, as long as the corresponding model-based MPC is inherently robust.
no code implementations • 6 May 2022 • Lukas Schwenkel, Alexander Hadorn, Matthias A. Müller, Frank Allgöwer
Under standard dissipativity and controllability assumptions, we can prove that the resulting linearly discounted economic MPC without terminal conditions achieves optimal asymptotic average performance up to an error that vanishes with growing prediction horizons.
no code implementations • 13 Apr 2022 • Ross Drummond, Stephen R. Duncan, Matthew C. Turner, Patricia Pauli, Frank Allgöwer
There is a growing debate on whether the future of feedback control systems will be dominated by data-driven or model-driven approaches.
no code implementations • 1 Apr 2022 • Stefan Wildhagen, Matthias Pezzutto, Luca Schenato, Frank Allgöwer
Networked Control Systems typically come with a limited communication bandwidth and thus require special care when designing the underlying control and triggering law.
no code implementations • 14 Mar 2022 • Christian Klöppelt, Julian Berberich, Frank Allgöwer, Matthias A. Müller
This allows the entire scheme to be set up using only a priori measured data and knowledge of an upper bound on the system order.
no code implementations • 3 Mar 2022 • Henning Schlüter, Frank Allgöwer
We propose a stochastic MPC scheme using an optimization over the initial state for the predicted trajectory.
no code implementations • 25 Feb 2022 • Matthias Köhler, Julian Berberich, Matthias A. Müller, Frank Allgöwer
In this paper, we present a data-driven distributed model predictive control (MPC) scheme to stabilise the origin of dynamically coupled discrete-time linear systems subject to decoupled input constraints.
no code implementations • 16 Feb 2022 • Xin Wang, Julian Berberich, Jian Sun, Gang Wang, Frank Allgöwer, Jie Chen
To this end, we begin by presenting a dynamic event-triggering scheme (ETS) based on periodic sampling, and a discrete-time looped-functional approach, through which a model-based stability condition is derived.
no code implementations • 9 Feb 2022 • Michael Hertneck, Frank Allgöwer
Self-triggered control (STC) is a resource efficient approach to determine sampling instants for Networked Control Systems (NCS).
1 code implementation • 3 Jan 2022 • Patricia Pauli, Niklas Funcke, Dennis Gramlich, Mohamed Amine Msalmi, Frank Allgöwer
This paper is concerned with the training of neural networks (NNs) under semidefinite constraints, which allows for NN training with robustness and stability guarantees.
no code implementations • 8 Nov 2021 • Michael Hertneck, Frank Allgöwer
In the framework, a dynamic variable is used in addition to current state information to determine the next sampling instant, rendering the STC mechanism dynamic.
no code implementations • 25 Oct 2021 • Xin Wang, Jian Sun, Julian Berberich, Gang Wang, Frank Allgöwer, Jie Chen
Data-based representations for time-invariant linear systems with known or unknown system input matrices are first developed, along with a novel class of dynamic triggering schemes for sampled-data systems with time delays.
no code implementations • 14 Sep 2021 • Michael Hertneck, Frank Allgöwer
In this paper, a dynamic STC mechanism for nonlinear systems is proposed.
no code implementations • 25 Aug 2021 • Tim Martin, Frank Allgöwer
To tackle these drawbacks, we establish a polynomial representation of nonlinear functions based on a polynomial sector by Taylor's theorem and a set-membership for Taylor polynomials.
no code implementations • 20 Aug 2021 • Stefan Wildhagen, Frank Allgöwer
Rollout ETC addresses this issue by using a triggering and control law that is implicitly defined by the solution to an optimal control problem (OCP), instead of an explicit one as in classical ETC.
no code implementations • 6 Aug 2021 • Stefan Wildhagen, Frank Dürr, Frank Allgöwer
Event-triggered control (ETC) and time-triggered control (TTC), the classical concepts to determine the transmission instants for networked control systems, each come with drawbacks: It is difficult to tune ETC such that a certain bandwidth is respected, whereas TTC cannot adapt the sampling interval to the current state of the control system.
1 code implementation • 15 May 2021 • Amr Alanwar, Anne Koch, Frank Allgöwer, Karl Henrik Johansson
We consider the problem of computing reachable sets directly from noisy data without a given system model.
no code implementations • 7 May 2021 • Johannes Köhler, Matthias A. Müller, Frank Allgöwer
Robust constraint satisfaction is guaranteed by suitably incorporating these online validated bounds on the estimation error in a homothetic tube based MPC formulation.
1 code implementation • 31 Mar 2021 • Patricia Pauli, Dennis Gramlich, Julian Berberich, Frank Allgöwer
In this paper, we analyze the stability of feedback interconnections of a linear time-invariant system with a neural network nonlinearity in discrete time.
no code implementations • 30 Mar 2021 • Sebastian Schlor, Michael Hertneck, Stefan Wildhagen, Frank Allgöwer
As homomorphic encryptions are much more computationally demanding than secret sharing, they make up for a tremendous amount of the overall computational demand of this scheme.
no code implementations • 26 Mar 2021 • Stefan Wildhagen, Julian Berberich, Matthias Hirche, Frank Allgöwer
Recently, model- and data-based stability conditions for such systems were obtained by rewriting them as an interconnection of a linear time-invariant system and a delay operator, and subsequently, performing a robust stability analysis using a known bound on the gain of this operator.
no code implementations • 18 Mar 2021 • Tim Martin, Frank Allgöwer
In the context of dynamical systems, nonlinearity measures quantify the strength of nonlinearity by means of the distance of their input-output behaviour to a set of linear input-output mappings.
no code implementations • 4 Mar 2021 • Mohammad Alsalti, Julian Berberich, Victor G. Lopez, Frank Allgöwer, Matthias A. Müller
Willems et al. showed that all input-output trajectories of a discrete-time linear time-invariant system can be obtained using linear combinations of time shifts of a single, persistently exciting, input-output trajectory of that system.
no code implementations • 18 Feb 2021 • Christian Klöppelt, Lukas Schwenkel, Frank Allgöwer, Matthias A. Müller
In this paper, we provide non-averaged and transient performance guarantees for recently developed, tube-based robust economic model predictive control (MPC) schemes.
no code implementations • 15 Jan 2021 • Nils Wieler, Julian Berberich, Anne Koch, Frank Allgöwer
Given one open-loop measured trajectory of a single-input single-output discrete-time linear time-invariant system, we present a framework for data-driven controller design for closed-loop finite-horizon dissipativity.
no code implementations • 14 Jan 2021 • Julian Berberich, Johannes Köhler, Matthias A. Müller, Frank Allgöwer
We present a model predictive control (MPC) scheme to control linear time-invariant systems using only measured input-output data and no model knowledge.
Optimization and Control Systems and Control Systems and Control
no code implementations • 12 Jan 2021 • Johannes Köhler, Frank Allgöwer
In this paper, we provide a stability and performance analysis of model predictive control (MPC) schemes based on finite-tail costs.
no code implementations • 4 Jan 2021 • Stefan Wildhagen, Julian Berberich, Michael Hertneck, Frank Allgöwer
This article is concerned with data-driven analysis of discrete-time systems under aperiodic sampling, and in particular with a data-driven estimation of the maximum sampling interval (MSI).
no code implementations • 23 Nov 2020 • Patricia Pauli, Johannes Köhler, Julian Berberich, Anne Koch, Frank Allgöwer
In this paper, we present a method to analyze local and global stability in offset-free setpoint tracking using neural network controllers and we provide ellipsoidal inner approximations of the corresponding region of attraction.
no code implementations • 23 Nov 2020 • Robin Strässer, Julian Berberich, Frank Allgöwer
While most existing approaches focus on systems with polynomial dynamics, our approach allows to design controllers for unknown systems with rational or general non-polynomial dynamics.
1 code implementation • 17 Nov 2020 • Amr Alanwar, Anne Koch, Frank Allgöwer, Karl Henrik Johansson
In this paper, we propose a data-driven reachability analysis approach for unknown system dynamics.
no code implementations • 11 Sep 2020 • Julian Berberich, Carsten W. Scherer, Frank Allgöwer
We present a framework for systematically combining data of an unknown linear time-invariant system with prior knowledge on the system matrices or on the uncertainty for robust controller design.
no code implementations • 5 Jun 2020 • Michael Hertneck, Frank Allgöwer
When designing Networked Control Systems (NCS), the maximum allowable transmission interval (MATI) is an important quantity, as it provides the admissible time between two transmission instants.
no code implementations • 25 May 2020 • Johannes Köhler, Matthias A. Müller, Frank Allgöwer
The paper also contains novel results for MPC without terminal constraints with positive semidefinite input/output stage costs that are of independent interest.
no code implementations • 7 May 2020 • Johannes Köhler, Lukas Schwenkel, Anne Koch, Julian Berberich, Patricia Pauli, Frank Allgöwer
Our theoretical findings support various recent studies by showing that 1) adaptive feedback strategies are required to reliably contain the COVID-19 outbreak, 2) well-designed policies can significantly reduce the number of fatalities compared to simpler ones while keeping the amount of social distancing measures on the same level, and 3) imposing stronger social distancing measures early on is more effective and cheaper in the long run than opening up too soon and restoring stricter measures at a later time.
2 code implementations • 6 May 2020 • Patricia Pauli, Anne Koch, Julian Berberich, Paul Kohler, Frank Allgöwer
More specifically, we design an optimization scheme based on the Alternating Direction Method of Multipliers that minimizes not only the training loss of an NN but also its Lipschitz constant resulting in a semidefinite programming based training procedure that promotes robustness.
no code implementations • 9 Apr 2020 • Janani Venkatasubramanian, Johannes Köhler, Julian Berberich, Frank Allgöwer
We present a novel strategy for robust dual control of linear time-invariant systems based on gain scheduling with performance guarantees.
no code implementations • 15 Mar 2020 • Julian Berberich, Johannes Köhler, Matthias A. Müller, Frank Allgöwer
We propose a purely data-driven model predictive control (MPC) scheme to control unknown linear time-invariant systems with guarantees on stability and constraint satisfaction in the presence of noisy data.
no code implementations • 22 Dec 2019 • Julian Nubert, Johannes Köhler, Vincent Berenz, Frank Allgöwer, Sebastian Trimpe
Fast feedback control and safety guarantees are essential in modern robotics.
no code implementations • 21 Oct 2019 • Julian Berberich, Johannes Köhler, Matthias A. Müller, Frank Allgöwer
We propose a data-driven tracking model predictive control (MPC) scheme to control unknown discrete-time linear time-invariant systems.
no code implementations • 12 Jun 2019 • Miel Sharf, Anne Koch, Daniel Zelazo, Frank Allgöwer
In this paper, we develop a data-based controller design framework for diffusively coupled systems with guaranteed convergence to an $\epsilon$-neighborhood of the desired formation.
no code implementations • 11 Jun 2019 • Julian Berberich, Johannes Köhler, Matthias A. Müller, Frank Allgöwer
First, we prove exponential stability of a nominal data-driven MPC scheme with terminal equality constraints in the case of no measurement noise.
no code implementations • 11 Jun 2018 • Michael Hertneck, Johannes Köhler, Sebastian Trimpe, Frank Allgöwer
A supervised learning framework is proposed to approximate a model predictive controller (MPC) with reduced computational complexity and guarantees on stability and constraint satisfaction.