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This paper highlights recent development of fuel cell hybrid vehicle (FCHV) models using the Fuel Cell Library (FCL), the Vehicle Dynamics Library (VDL), and Electrification Library (EL) from Modelon. A flexible model architecture is implemented to support physical modeling of such large scale, multi-domain vehicle system. The top-level model consists of a hydrogen fuel cell subsystem with detaile
The problem of low-rank approximation with convex constraints, which appears in data analysis, system identification, model order reduction, low-order controller design and low-complexity modelling is considered. Given a matrix, the objective is to find a low-rank approximation that meets rank and convex constraints, while minimizing the distance to the matrix in the squared Frobenius norm. In man
Harmonic periods have wide applicability in industrial real-time systems. Rate monotonic (RM) is able to schedule task sets with harmonic periods up to 100% utilization. Also, if there is no release jitter and execution time variation, RM and EDF generate the same schedule for each instance of a task. As a result, all instances of a task are interfered by the same amount of workload. This property
Cloud computing has emerged as an inexpensive and powerful computing paradigm, to the point that now even applications with hard deadlines are executed in the cloud. It may happen, due to unexpected events, that an application becomes popular and receives a lot of attention and client requests in a short period of time. Provisioning computing capacity for such applications is quite a difficult tas
We present a method for augmenting a nominal controller with a peak filter to achieve improved rejection of narrowband disturbances. The method is based on consideration of the open-loop Nyquist curve, which arguably makes it more intuitive and flexible than previous approaches. We also comment on some implementation aspects, and give an application example based on a control problem at a particle
Sudden cardiac arrest is the second most common cause of death in Sweden, following tumors. Annually, 10 000 people are subject to sudden cardiac arrest outside of hospital in the country.Following sudden cardiac arrest, blood circulation in the body ceases, and the brain is subject to irreversible damage within minutes. The treatment consists mainly of mechanical chest compressions to circulate b
We reconsider the variational problem of finding the shape of a vertically hanging rope such that its elongation, due to the rope’s own weight and that of a load attached at its lower end, is minimum. The known solution is recalled and the missing proof of optimality is supplied.
We analyze the local convergence of proximal splitting algorithms to solve optimization problems that are convex besides a rank constraint. For this, we show conditions under which the proximal operator of a function involving the rank constraint is locally identical to the proximal operator of its convex envelope, hence implying local convergence. The conditions imply that the non-convex algorith
Cloud computing infrastructures are powering most of the web hosting services that we use at all times. A recent failure in the Amazon cloud infrastructure made many of the website that we use on a hourly basis unavailable1. This illustrates the importance of cloud applications being able to absorb peaks in workload, and at the same time to tune their power requirements to the power and energy cap
In this paper we consider L1 optimal and H-infinity optimal control problems for a particular class of Positive Bilinear Systems that arise in drug dosage design for HIV treatment. Starting from existent characterizations of the L1-norm for positive systems, a convex formulation for the first problem is provided. As for the H-infinity case, we propose an algorithm based on the iterative solution o
In the framework of robotics, Reinforcement Learning (RL) deals with the learning of a task by the robot itself. This paper presents a hierarchical planning approach in which the robot learns the optimal behavior for different levels. For high-level discrete actions, Q-learning was chosen, whereas for the low level we utilize Policy Improvement with Path Integrals (PI^2) algorithm to learn the par
This work presents a 2.0mm2 128×16 massive MIMO detector IC that provides 21dB array gain and 16x multiplexing gain at the system level. The detector implements iterative expectation-propagation detection (EPD) for up to 256-QAM modulation. Tested with measured channel data [1], the detector achieves 4.3dB processing gain over state-of-the-art massive MlMo detectors [2, 3], enabling 2.7x reduction
The purpose of this paper is to analyse transient dynamics in adaptive control using statistical concentration bounds. For maximal clarity, the study is limited to a linear first order system with a single uncertain parameter. Two types of bounds are given: First we prove probabilistic bounds on the parameter estimation error as a function of time. In particular, we prove that the estimation error
Forward–backward and Douglas–Rachford splitting are methods for structured nonsmooth optimization. With the aim to use smooth optimization techniques for nonsmooth problems, the forward–backward and Douglas–Rachford envelopes where recently proposed. Under specific problem assumptions, these envelope functions have favorable smoothness and convexity properties and their stationary points coincide
We consider the problem of finding an event-based sampling scheme that optimizes the trade-off between average sampling rate and control performance in a linear-quadratic-Gaussian (LQG) control problem setting with output feedback. Our analysis is based on a recently presented sampled-data controller structure, which remains LQG-optimal for any choice of sampling scheme. We show that optimization
This paper describes a method to compute frame size estimates to be used in quasi Worst-Case Transmission Times (qWCTT) for cameras that transmit frames over IP-based communication networks. The precise determination of qWCTT allows us to model the network access scheduling problem as a multiframe problem and to re-use theoretical results for network scheduling. The paper presents a set of experim
Innovation and entrepreneurship are essential processes for human development, market growth, and technological breakthroughs, and it is vital for economic growth. Despite its importance, innovation is inherently difficult to measure and hence it is almost impossible for an individual or organization to know how they can improve their innovation output or claim that they are great at innovation. T
We study a linear quadratic control problem for transportation optimization on a directed line graph. We show that the solution to the Riccati equation associated with this problem is highly structured. The feedback law is almost upper triangular, and the synthesis of the feedback law is given by a recursion, making it scalable. The structure of the feedback law also allows for an efficient realiz
