8 citations · 12 across the 8 of their papers we have counts for
10 papers
Static output-feedback stabilization is NP-hard
Johan Löfberg
We prove that unrestricted static output-feedback stabilization is NP-hard, already in the single-input multiple-output case. More precisely, we give a polynomial-time many-one red…
The Global Asymptotic Stability Problem for Linear MPC Is Undecidable
Johan Löfberg
We prove that deciding global asymptotic stability for constrained finite-horizon linear model predictive control is undecidable. This holds at horizon one with identity state, inp…
Second Order Zarankiewicz Number
Johan Löfberg, Liqun Qi
We introduce the \emph{second order Zarankiewicz number} for irreducible doubly simple biquadratic forms with , together with the intermediate recursive-li…
A kernel proof of the De Cock-De Moor Lyapunov identity
Jonas Gillberg, Johan Löfberg
We prove the rank-one Lyapunov spectral identity recorded as Problem 9.1 in the 2004 collection of unsolved problems in mathematical systems and control theory. Let solve t…
Exact and Asymptotic Values for Weak Limited Augmented Zarankiewicz Numbers in the Case
Liqun Qi, Johan Löfberg, Yannan Chen
We determine the exact weak limited augmented Zarankiewicz numbers for all : \[ z_{wL}(m,3)= \begin{cases} m+3+\left\lceil \dfrac{m}{2}\right\rceil+1, & 9\le…
Sparse Feedback Implementation for Sender-Receiver Transportation Linear-Quadratic Control
Anders Hansson, Johan Löfberg
We study a sparse linear-quadratic problem for transportation dynamics. The sparsity pattern has a natural directed-graph representation in which vertices are storage locations and…
A characteristic function framework for chance constraint programming in stochastic model predictive control
Yuwei Ying, Johan Löfberg, Anders Hansson
The computation of chance constraints in stochastic model predictive control is often numerically challenging due to the non-Gaussian nature of the disturbances. To overcome this p…
Fast or Cheap: Time and Energy Optimal Control of Ship-to-Shore Cranes
Filipe Marques Barbosa, Anton Kullberg, Johan Löfberg
This paper addresses the trade-off between time- and energy-efficiency for the problem of loading and unloading a ship. Container height constraints and energy consumption and rege…
Time-optimal control of cranes subject to container height constraints
Filipe Marques Barbosa, Johan Löfberg
The productivity and efficiency of port operations strongly depend on how fast a ship can be unloaded and loaded again. With this in mind, ship-to-shore cranes perform the critical…
Model Reduction using a Frequency-Limited H2-Cost
Daniel Petersson, Johan Löfberg
We propose a method for model reduction on a given frequency range, without the use of input and output filter weights. The method uses a nonlinear optimization approach to minimiz…