Search Results for author: Alberto Bemporad

Found 25 papers, 5 papers with code

Linear and nonlinear system identification under $\ell_1$- and group-Lasso regularization via L-BFGS-B

1 code implementation6 Mar 2024 Alberto Bemporad

In this paper, we propose an approach for identifying linear and nonlinear discrete-time state-space models, possibly under $\ell_1$- and group-Lasso regularization, based on the L-BFGS-B algorithm.

Learning disturbance models for offset-free reference tracking

no code implementations18 Dec 2023 Pablo Krupa, Mario Zanon, Alberto Bemporad

This work presents a nonlinear MPC framework that guarantees asymptotic offset-free tracking of generic reference trajectories by learning a nonlinear disturbance model, which compensates for input disturbances and model-plant mismatch.

Harmonic model predictive control for tracking periodic references

no code implementations25 Oct 2023 Pablo Krupa, Daniel Limon, Alberto Bemporad, Teodoro Alamo

Harmonic model predictive control (HMPC) is a recent model predictive control (MPC) formulation for tracking piece-wise constant references that includes a parameterized artificial harmonic reference as a decision variable, resulting in an increased performance and domain of attraction with respect to other MPC formulations.

Model Predictive Control

Data-Driven Synthesis of Configuration-Constrained Robust Invariant Sets for Linear Parameter-Varying Systems

no code implementations13 Sep 2023 Manas Mejari, Sampath Kumar Mulagaleti, Alberto Bemporad

We present a data-driven method to synthesize robust control invariant (RCI) sets for linear parameter-varying (LPV) systems subject to unknown but bounded disturbances.

Scheduling

Computation of safe disturbance sets using implicit RPI sets

no code implementations12 Sep 2023 Sampath Kumar Mulagaleti, Alberto Bemporad, Mario Zanon

Given a stable linear time-invariant (LTI) system subject to output constraints, we present a method to compute a set of disturbances such that the reachable set of outputs matches as closely as possible the output constraint set, while being included in it.

Computational Efficiency

Parameter Dependent Robust Control Invariant Sets for LPV Systems with Bounded Parameter Variation Rate

no code implementations5 Sep 2023 Sampath Kumar Mulagaleti, Manas Mejari, Alberto Bemporad

We present a method to synthesize parameter-dependent robust control invariant (PD-RCI) sets for LPV systems with bounded parameter variation, in which invariance is induced using PD-vertex control laws.

Scheduling

Self-concordant Smoothing for Large-Scale Convex Composite Optimization

1 code implementation4 Sep 2023 Adeyemi D. Adeoye, Alberto Bemporad

We introduce a notion of self-concordant smoothing for minimizing the sum of two convex functions, one of which is smooth and the other may be nonsmooth.

Counter-example guided inductive synthesis of control Lyapunov functions for uncertain systems

no code implementations17 Mar 2023 Daniele Masti, Filippo Fabiani, Giorgio Gnecco, Alberto Bemporad

We propose a counter-example guided inductive synthesis (CEGIS) scheme for the design of control Lyapunov functions and associated state-feedback controllers for linear systems affected by parametric uncertainty with arbitrary shape.

Global and Preference-based Optimization with Mixed Variables using Piecewise Affine Surrogates

1 code implementation9 Feb 2023 Mengjia Zhu, Alberto Bemporad

Optimization problems involving mixed variables, i. e., variables of numerical and categorical nature, can be challenging to solve, especially in the presence of complex constraints.

An active learning method for solving competitive multi-agent decision-making and control problems

no code implementations23 Dec 2022 Filippo Fabiani, Alberto Bemporad

To identify a stationary action profile for a population of competitive agents, each executing private strategies, we introduce a novel active-learning scheme where a centralized external observer (or entity) can probe the agents' reactions and recursively update simple local parametric estimates of the action-reaction mappings.

Active Learning Decision Making

Learning Critical Scenarios in Feedback Control Systems for Automated Driving

no code implementations26 Sep 2022 Mengjia Zhu, Alberto Bemporad, Maximilian Kneissl, Hasan Esen

We examine the approach on the case of a feedback control system for automated driving, for which we suggest the design of the objective function expressing the criticality of scenarios.

Active Learning for Regression by Inverse Distance Weighting

no code implementations14 Apr 2022 Alberto Bemporad

This paper proposes an active learning (AL) algorithm to solve regression problems based on inverse-distance weighting functions for selecting the feature vectors to query.

Active Learning Classification +1

Training Recurrent Neural Networks by Sequential Least Squares and the Alternating Direction Method of Multipliers

no code implementations31 Dec 2021 Alberto Bemporad

This paper proposes a novel algorithm for training recurrent neural network models of nonlinear dynamical systems from an input/output training dataset.

SCORE: Approximating Curvature Information under Self-Concordant Regularization

no code implementations14 Dec 2021 Adeyemi D. Adeoye, Alberto Bemporad

In this paper, we propose the SCORE (self-concordant regularization) framework for unconstrained minimization problems which incorporates second-order information in the Newton-decrement framework for convex optimization.

Second-order methods

Data-driven synthesis of Robust Invariant Sets and Controllers

no code implementations18 Nov 2021 Sampath Kumar Mulagaleti, Alberto Bemporad, Mario Zanon

This paper presents a method to identify an uncertain linear time-invariant (LTI) prediction model for tube-based Robust Model Predictive Control (RMPC).

Model Predictive Control

Recurrent Neural Network Training with Convex Loss and Regularization Functions by Extended Kalman Filtering

no code implementations4 Nov 2021 Alberto Bemporad

We also explore the use of the algorithm in data-driven nonlinear model predictive control and its relation with disturbance models for offset-free closed-loop tracking.

Model Predictive Control

Piecewise linear regression and classification

no code implementations10 Mar 2021 Alberto Bemporad

This paper proposes a method for solving multivariate regression and classification problems using piecewise linear predictors over a polyhedral partition of the feature space.

Classification General Classification +1

Exact and Heuristic Methods with Warm-start for Embedded Mixed-Integer Quadratic Programming Based on Accelerated Dual Gradient Projection

no code implementations22 Jan 2021 Vihangkumar V. Naik, Alberto Bemporad

Moreover, in order to find an integer feasible combination of the binary variables upfront, two heuristic approaches are presented: ($i$) without using B&B, and ($ii$) using B&B with a significantly reduced number of QP relaxations.

Optimization and Control Systems and Control Systems and Control

Reduction of the Number of Variables in Parametric Constrained Least-Squares Problems

no code implementations18 Dec 2020 Alberto Bemporad, Gionata Cimini

For linearly constrained least-squares problems that depend on a vector of parameters, this paper proposes techniques for reducing the number of involved optimization variables.

Blocking Model Predictive Control

Safe Reinforcement Learning via Projection on a Safe Set: How to Achieve Optimality?

no code implementations2 Apr 2020 Sebastien Gros, Mario Zanon, Alberto Bemporad

For all its successes, Reinforcement Learning (RL) still struggles to deliver formal guarantees on the closed-loop behavior of the learned policy.

Policy Gradient Methods Q-Learning +3

Constrained Controller and Observer Design by Inverse Optimality

no code implementations23 Mar 2020 Mario Zanon, Alberto Bemporad

When a baseline linear controller exists that is already well tuned in the absence of constraints and MPC is introduced to enforce them, one would like to avoid altering the original linear feedback law whenever they are not active.

Model Predictive Control

Efficient Calibration of Embedded MPC

1 code implementation29 Nov 2019 Marco Forgione, Dario Piga, Alberto Bemporad

Model Predictive Control (MPC) is a powerful and flexible design tool of high-performance controllers for physical systems in the presence of input and output constraints.

Systems and Control Systems and Control Optimization and Control

Active preference learning based on radial basis functions

no code implementations28 Sep 2019 Alberto Bemporad, Dario Piga

The algorithm described in this paper aims at reaching the global optimizer by iteratively proposing the decision maker a new comparison to make, based on actively learning a surrogate of the latent (unknown and perhaps unquantifiable) objective function from past sampled decision vectors and pairwise preferences.

Bayesian Optimization

Global optimization via inverse distance weighting and radial basis functions

no code implementations15 Jun 2019 Alberto Bemporad

Global optimization problems whose objective function is expensive to evaluate can be solved effectively by recursively fitting a surrogate function to function samples and minimizing an acquisition function to generate new samples.

Bayesian Optimization

OSQP: An Operator Splitting Solver for Quadratic Programs

2 code implementations21 Nov 2017 Bartolomeo Stellato, Goran Banjac, Paul Goulart, Alberto Bemporad, Stephen Boyd

We present a general purpose solver for convex quadratic programs based on the alternating direction method of multipliers, employing a novel operator splitting technique that requires the solution of a quasi-definite linear system with the same coefficient matrix at almost every iteration.

Optimization and Control

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