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Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 251.
    Iwaki, Takuya
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Reglerteknik.
    Johansson, Karl H.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Reglerteknik.
    LQG Control and Scheduling Co-Design for Wireless Sensor and Actuator Networks2018Inngår i: IEEE Workshop on Signal Processing Advances in Wireless Communications, SPAWC, Institute of Electrical and Electronics Engineers Inc. , 2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper studies a co-design problem of control, scheduling and routing over a multi-hop sensor and actuator network subject to energy-saving consideration. Sensors are observing multiple independent linear systems and transmit their data to actuators in which controllers are co-located. We formulate an optimization problem, minimizing a linear combination of the averaged linear quadratic Gaussian control performance and the averaged transmission energy consumption. Optimal solutions are derived and their performance is illustrated in a numerical example. Algorithms to reconfigure routing between sensors and actuators in case of link disconnection are also provided.

  • 252.
    Iwaki, Takuya
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Intelligenta system, Reglerteknik.
    Wu, J.
    Johansson, Karl Henrik
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Intelligenta system, Reglerteknik.
    Event-triggered Feedforward Control subject to Actuator Saturation for Disturbance Compensation∗2018Inngår i: 2018 European Control Conference, ECC 2018, Institute of Electrical and Electronics Engineers (IEEE), 2018, s. 501-506, artikkel-id 8550115Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Feedfoward control is widely used to compensate measurable external disturbances. This paper studies feedforward control using an event-triggered sensor. Stability conditions when the feedback control is subject to actuator saturation are derived. We also obtain stability conditions of eventtriggered feedforward control with anti-windup compensation. A numerical example shows that event-triggered feedforward control significantly reduces communication between the sensor and the controller without performance degradation compared with continuous-time feedforward control.

  • 253.
    Iwaki, Takuya
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Wu, Yuchi
    Wu, Junfeng
    Sandberg, Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Johansson, Karl Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Wireless Sensor Network Scheduling for Remote Estimation under Energy Constraints2017Inngår i: 2017 IEEE 56TH ANNUAL CONFERENCE ON DECISION AND CONTROL (CDC), IEEE , 2017, s. 3362-3367Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper studies a design problem of how a group of wireless sensors are selected and scheduled to transmit data efficiently over a multi-hop network subject to energy-saving consideration, when they are observing multiple independent discrete-time linear systems. Each time instant, some sensors are selected to transmit their measurements to a remote estimator. We formulate an optimization problem, minimizing a linear combination of the averaged estimation error and the averaged transmission energy consumption to obtain suitable network scheduling and estimation algorithms. Necessary conditions for optimality are derived and these conditions help trim the feasible solution space so that the optimal solution can be computed efficiently. A numerical example is provided to demonstrate the theoretical results.

  • 254.
    Jacobsson, Krister
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Andrew, Lachlan L. H.
    Tang, Ao
    Johansson, Karl Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Hjalmarsson, Håkan
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Low, Steven H.
    California Institute of Technology.
    ACK-clocking dynamics: Modelling the interaction between windows and the network2008Inngår i: 27TH IEEE CONFERENCE ON COMPUTER COMMUNICATIONS (INFOCOM): VOLS 1-5, 2008, s. 181-185Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A novel continuous time fluid flow model of the dynamics of the interaction between ACK-clocking and the link buffer is presented.. A fundamental integral equation relating the instantaneous flow rate and the window dynamics is derived. Properties of the model, such as well-posedness and stability, are investigated. Packet level experiments verily that this new model is more accurate than existing models, correctly predicting qualitatively different behaviors, for example when round trill delays are heterogeneous.

    Fulltekst (pdf)
    network_infocom08_model
  • 255.
    Jacobsson, Krister
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Hjalmarsson, Håkan
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Johansson, Karl Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Towards accurate congestion control models: validation and stability analysis2006Konferansepaper (Fagfellevurdert)
    Fulltekst (pdf)
    network_mtns06_link_model
  • 256.
    Jacobsson, Krister
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Hjalmarsson, Håkan
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Johansson, Karl Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Unbiased bandwidth estimation in communication protocols2005Inngår i: Proceedings of the 16th IFAC World Congress, 2005, IFAC , 2005Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Heterogeneous communication networks with their variety of application demands, uncertain time-varying trafc load, and mixture of wired and wireless links pose several challenging problem in modeling and control. In this paper we focus on bandwidth estimation and elucidate why estimates based directly on bandwidth samples are biased. Previously, this phenomenon has been observed but not properly explained, it seems. Standard techniques for bandwidth estimation are based on measurements of inter-arrival times of packets as the bandwidth is proportional to the inverse of the  nterarrival time. Two main classes of bandwidth estimators are analyzed wrt how variations in the inter-arrival times affect the estimates. It is shown that linear time-invariant ltering of instantaneous bandwidth estimates does not change the bias. In contrast to this, smoothing the inter-arrival-time samples does give a bias reduction which depends on the properties of the smoothing lter. Hence, with such approach, noise attenuation can be traded against tracking ability wrt changes in the actual bandwidth.

    Fulltekst (pdf)
    network_ifac05_bw
  • 257.
    Jacobsson, Krister
    et al.
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Hjalmarsson, Håkan
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Möller, Niels
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Johansson, Karl Henrik
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Estimation of RTT and bandwidth for congestion Control Applications in Communication Networks2004Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Heterogeneous communication networks with their variety of application demands, uncertain time-varying traffic load, and mixture of wired and wireless links pose several challenging problem in modeling and control. In this paper we focus on the round-trip time (RTT), which is a particularly important variable for efficient end-to-end congestion control, and on bandwidth estimation. Based on a simple aggregated model of the network, an algorithm combining a Kalman filter and a change detection algorithm is proposed for RTT estimation. It is illustrated on real data that this algorithm provides estimates of significantly better accuracy as compared to the RTT estimator currently used in TCP, especially in scenarios where new cross-trafficflows cause bottle-neck queues to rapidly build up which in turn induces rapid changes of the RTT.

    Standard techniques for bandwidth estimation is based on measurements of inter-arrival times of packets as the bandwidth is proportional to the inverse of the inter-arrival time. Two main classes of bandwidth estimators are analyzed wrt how variations in the inter-arrival times affect the estimates. It is shown that linear time-invariant filtering of instantaneous bandwidth estimates does not change the bias. In contrast to this, smoothing the inter-arrival-time samples, does give a bias reduction which depends on the smoothing filter. Hence, with such approach, noise attenuation can be traded against tracking ability wrt changes in the actual bandwidth.

    Fulltekst (pdf)
    network_rtt-est_cdc04
  • 258.
    Jacobsson, Krister
    et al.
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Hjalmarsson, Håkan
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Möller, Niels
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Johansson, Karl Henrik
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Round trip time estimation in communication networks using adaptive Kalman filtering2004Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Heterogeneous communication networks with their variety of application demands, uncertain time-varying traffic load, and mixture of wired and wireless links pose several challenging problem in modeling and control. In this paper we focus on the roundtrip time (RTT), which is a particularly important variable for efficient end-to-end congestion control. Based on a simple aggregated model of the network, an algorithm combining a Kalmanfilter and a change detection algorithm is proposed for RTT estimation. It is illustrated on real data that this algorithm provides estimates of significantly better accuracy as compared to the RTT estimator currently used in TCP, especially in scenarios where new cross-trafficflows cause a bottle-neck link to rapidly build up a queue, which in turn induces rapid changes of the RTT.

    Fulltekst (pdf)
    network_rm04
  • 259.
    Jacobsson, Krister
    et al.
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Möller, Niels
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Johansson, Karl Henrik
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Hjalmarsson, Håkan
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Some modeling and estimation issues in control of heterogeneous networks2004Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Heterogeneous communication networks with their variety of application demands, uncertain time-varying trafc load, and mixture of wired and wireless links pose several challenging problem in modeling and control. In this paper we focus on the round-trip time (RTT), which is a particularly important variable for efficient end-to-end congestion control. Based on a simple aggregated model of the network, an algorithm combining a Kalman lter and a change detection algorithm is proposed for RTT estimation. It is illustrated on real data that this algorithm provides estimates of significantly better accuracy as compared to the RTT estimator currently used in TCP.We also analyze how wireless links affect the RTT distribution. Link re-transmissions induce delays which do not conform to the assumptions on which the transport protocol is based. This causes undesired TCP control actions which reduce throughput. A link layer solution based on adding carefully selected delays to certain packets is proposed to counteract this problem.

    Fulltekst (pdf)
    network_mtns04
  • 260.
    Jafarian, Matin
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Intelligenta system, Reglerteknik.
    Mamduhi, Mohammad H.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Intelligenta system, Reglerteknik.
    Johansson, Karl H.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Intelligenta system, Reglerteknik.
    Stochastic phase-cohesiveness of discrete-time Kuramoto oscillators in a frequency-dependent tree network2019Inngår i: Proceedings 2019 18th European Control Conference (ECC), IEEE , 2019, s. 1987-1992Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents the notion of stochastic phase-cohesiveness based on the concept of recurrent Markov chains and studies the conditions under which a discrete-time stochastic Kuramoto model is phase-cohesive. It is assumed that the exogenous frequencies of the oscillators are combined with random variables representing uncertainties. A bidirectional tree network is considered such that each oscillator is coupled to its neighbors with a coupling law which depends on its own noisy exogenous frequency. In addition, an undirected tree network is studied. For both cases, a sufficient condition for the common coupling strength (kappa) and a necessary condition for the sampling-period are derived such that the stochastic phase-cohesiveness is achieved. The analysis is performed within the stochastic systems framework and validated by means of numerical simulations.

  • 261.
    Jafarian, Matin
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Reglerteknik.
    Yi, Xinlei
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Reglerteknik.
    Pirani, Mohammad
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Reglerteknik.
    Sandberg, Henrik
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Reglerteknik.
    Johansson, Karl H.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Reglerteknik.
    Synchronization of Kuramoto oscillators in a bidirectional frequency-dependent tree network2018Inngår i: 2018 IEEE CONFERENCE ON DECISION AND CONTROL (CDC), IEEE , 2018, s. 4505-4510Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper studies the synchronization of a finite number of Kuramoto oscillators in a frequency-dependent bidirectional tree network. We assume that the coupling strength of each link in each direction is equal to the product of a common coefficient and the exogenous frequency of its corresponding source oscillator. We derive a sufficient condition for the common coupling strength in order to guarantee frequency synchronization in tree networks. Moreover, we discuss the dependency of the obtained bound on both the graph structure and the way that exogenous frequencies are distributed. Further, we present an application of the obtained result by means of an event-triggered algorithm for achieving frequency synchronization in a star network assuming that the common coupling coefficient is given.

  • 262. James, Weimer
    et al.
    Varagnolo, Damiano
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Stankovic, Milos
    Johansson, Karl Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Parameter-invariant detection of unknown inputs in networked systems2013Inngår i: 2013 IEEE 52nd Annual Conference on Decision and Control (CDC), IEEE conference proceedings, 2013, s. 4379-4384Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This work considers the problem of detecting unknown inputs in networked systems whose dynamics are governed by time-varying unknown parameters. We propose a strategy in opposition to the commonly employed approach of first estimating the unknown parameters and then using the estimates as the true parameter values for detection, e.g. maximum-likelihood approaches. The suggested detection scheme employs test statistics that are invariant to the unknown parameters and do not rely on parameter estimation. We specifically consider the case of severe lack of prior knowledge, i.e., the problem of detecting unknown inputs when nothing is known of the system but some primitive structural properties, namely that the system is a linear network, subject to Gaussian noise, and that a certain input signal is either present or not. The aim is thus to analyze the structure and performances of invariant tests in a limiting case, specifically where the amount of prior information is minimal. The developed test is proven to be maximally invariant to the unknown parameters and Uniformly Most Powerful Invariant (UMPI). Simulation results indicate that for arbitrary networked systems the parameterinvariant detector achieves a specified probability of false alarm while ensuring that the probability of detection is maximized.

  • 263.
    Jang, Dohyun
    et al.
    Seoul Natl Univ, Dept Mech & Aerosp Engn, Seoul, South Korea..
    Son, Clark Youngdong
    Seoul Natl Univ, Dept Mech & Aerosp Engn, Seoul, South Korea..
    Yoo, Jaehyun
    Hankyong Natl Univ, Dept Elect Elect & Control Engn, Anseong, South Korea..
    Kim, H. Jin
    Seoul Natl Univ, Dept Mech & Aerosp Engn, Seoul, South Korea..
    Johansson, Karl H.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Intelligenta system, Reglerteknik. KTH, Skolan för elektroteknik och datavetenskap (EECS), Centra, ACCESS Linnaeus Centre.
    Efficient networked UAV control using event-triggered predictive control2019Inngår i: IFAC PAPERSONLINE, ELSEVIER , 2019, Vol. 52, nr 15, s. 412-417Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, we propose a method to improve the networked UAV control system using event-triggered control and model predictive control (MPC). Although the UAV control over the network has many advantages, it involves a long-time delay and packet loss, which adversely affect real-time control performance. Delay compensation algorithms in the networked control system (NCS) have been proposed to address such issues, however, they do not consider the resource limit of the network so that the network congestion may occur. In that case, the packet loss and network delay issues can even be worsened. In this study, we propose a method to reduce the generation of less important control signals and to use the network more efficiently by using event-triggered control. Since the event-triggered control method is also influenced by the network delay, an event trigger function suitable for NCS is designed. We validated the effectiveness of networked UAV control system and event-triggered control by simulation.

  • 264.
    Jang, Dohyun
    et al.
    SNU, Dept Mech & Aerosp Engn, Seoul, South Korea.;ASRI, Seoul, South Korea..
    Yoo, Jachyun
    Hankyong Natl Univ, Dept Elect Elect & Control Engn, Anseong, South Korea..
    Son, Clark Youngdong
    SNU, Dept Mech & Aerosp Engn, Seoul, South Korea.;ASRI, Seoul, South Korea..
    Kim, H. Jin
    SNU, Dept Mech & Aerosp Engn, Seoul, South Korea.;ASRI, Seoul, South Korea..
    Johansson, Karl H.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Intelligenta system, Reglerteknik.
    Networked operation of a UAV using Gaussian process-based delay compensation and model predictive control2019Inngår i: 2019 International Conference on Robotics And Automation (ICRA) / [ed] Howard, A Althoefer, K Arai, F Arrichiello, F Caputo, B Castellanos, J Hauser, K Isler, V Kim, J Liu, H Oh, P Santos, V Scaramuzza, D Ude, A Voyles, R Yamane, K Okamura, A, Institute of Electrical and Electronics Engineers (IEEE), 2019, Vol. 2019, s. 9216-9222Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This study addresses an operation of unmanned aerial vehicles (UAVs) in a network environment where there is time-varying network delay. The network delay entails undesirable effects on the stability of the UAV control system due to delayed state feedback and outdated control input. Although several networked control algorithms have been proposed to deal with the network delay, most existing studies have assumed that the plant dynamics is known and simple, or the network delay is constant. These assumptions are improper to multirotor-type UAVs because of their nonlinearity and time-sensitive characteristics. To deal with these problems, we propose a networked control system using model predictive control (MPC) designed under the consideration of multirotor characteristics. We also apply a Gaussian process (GP) to learn an unknown nonlinear model, which increases the accuracy of path planning and state estimation. Flight experiments show that the proposed algorithm successfully compensates the network delay and Gaussian process learning improves the UAV's path tracking performance.

  • 265.
    Jansson, Henrik
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Kozica, Eermin
    Scania CV.
    Sahlholm, Per
    Scania CV.
    Johansson, Karl Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Improved road grade estimation using sensor fusion2006Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A method for estimation of the road grade basedon standard mounted sensors in a heavy duty vehicle ispresented. The method combines information from a barometerand a GPS with velocity and torque measurements of conventionaltype. The sensor information is adaptively integratedusing extended Kalman filtering. This provides a systematicmethod for dealing with varying uncertainty in the sensors.The method can handle periods of missing or unreliable datafrom one or several sensors, e.g., occasions when the satellitecoverage is low or when the brakes are applied.

  • 266. Jia, Qing-Shan
    et al.
    Johansson, Karl Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Guest editorial: event-based control and optimization2014Inngår i: Discrete event dynamic systems, ISSN 0924-6703, E-ISSN 1573-7594, Vol. 24, nr 2, s. 99-102Artikkel i tidsskrift (Fagfellevurdert)
  • 267.
    Jin, Li
    et al.
    Massachusetts Institute of Technology.
    Čičić, Mladen
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Intelligenta system, Reglerteknik.
    Amin, Saurabh
    Massachusetts Institute of Technology.
    Johansson, Karl H.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Intelligenta system, Reglerteknik.
    Modeling the impact of vehicle platooning on highway congestion: A fluid qeuing approach2018Inngår i: HSCC 2018 - Proceedings of the 21st International Conference on Hybrid Systems: Computation and Control (part of CPS Week), Association for Computing Machinery (ACM), 2018, s. 237-246Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Vehicle platooning is a promising technology that can lead to significant fuel savings and emission reduction. However, the macroscopic impact of vehicle platoons on highway traffic is not yet well understood. In this article, we propose a new fluid queuing model to study the macroscopic interaction between randomly arriving vehicle platoons and the background traffic at highway bottlenecks. This model, viewed as a stochastic switched system, is analyzed for two practically relevant priority rules: proportional (or mixed) and segmented priority. We provide intuitive stability conditions, and obtain bounds on the long-run average length and variance of queues for both priority rules. We use these results to study how platoon-induced congestion varies with the fraction of platooned vehicles, and their characteristics such as intra-platoon spacing and arrival rate. Our analysis reveals a basic tradeoff between congestion induced by the randomness of platoon arrivals, and efficiency gain due to a tighter intra-platoon spacing. This naturally leads to conditions under which the proportional priority is preferred over segmented priority. Somewhat surprisingly, our analytical results are in agreement with the simulation results based on a more sophisticated two-class cell transmission model.

    Fulltekst (pdf)
    fulltext
  • 268.
    Jin, Ming
    et al.
    Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA..
    Lavaei, Javad
    Univ Calif Berkeley, Dept Ind Engn & Operat Res, Berkeley, CA 94720 USA..
    Johansson, Karl H.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Reglerteknik.
    A Semidefinite Programming Relaxation under False Data Injection Attacks against Power Grid AC State Estimation2017Inngår i: 55th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2017, Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 236-243Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The integration of sensing and information technology renders the power grid susceptible to cyber-attacks. To understand how vulnerable the state estimator is, we study its behavior under the worst attacks possible. A general false data injection attack (FDIA) based on the AC model is formulated, where the attacker manipulates sensor measurements to mislead the system operator to make decisions based on a falsified state. To stage such an attack, the optimization problem incorporates constraints of limited resources (allowing only a limited number of measurements to be altered), and stealth operation (ensuring the cyber hack cannot be identified by the bad data detection algorithm). Due to the nonlinear AC power flow model and combinatorial selection of compromised sensors, the problem is nonconvex and cannot be solved in polynomial time; however, it is shown that convexification of the original problem based on a semidefinite programming (SDP) relaxation and a sparsity penalty is able to recover a near-optimal solution. This represents the first study to solve the AC-based FDIA. Simulations on a 30-bus system illustrate that the proposed attack requires only sparse sensor manipulation and remains stealthy from the residual-based bad data detection mechanism. In light of the analysis, this study raises new challenges on grid defense mechanism and attack detection strategy.

  • 269.
    Jin, Ming
    et al.
    Univ Calif Berkeley, Dept Ind Engn & Operat Res, Berkeley, CA 94720 USA..
    Lavaei, Javad
    Univ Calif Berkeley, Dept Ind Engn & Operat Res, Berkeley, CA 94720 USA..
    Johansson, Karl Henrik
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Reglerteknik.
    Power Grid AC-Based State Estimation: Vulnerability Analysis Against Cyber Attacks2019Inngår i: IEEE Transactions on Automatic Control, ISSN 0018-9286, E-ISSN 1558-2523, Vol. 64, nr 5, s. 1784-1799Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    To ensure grid efficiency and reliability, power system operators continuously monitor the operational characteristics of the grid through a critical process called state estimation (SE), which performs the task by filtering and fusing various measurements collected from grid sensors. This study analyzes the vulnerability of the key operation module, namely ac-based SE, against potential cyber attacks on data integrity, also known as false data injection attack (FDIA). A general form of FDIA can be formulated as an optimization problem, whose objective is to find a stealthy and sparse data injection vector on the sensor measurements with the aim of making the state estimate spurious and misleading. Due to the nonlinear ac measurement model and the cardinality constraint, the problem includes both continuous and discrete nonlinearities. To solve the FDIA problem efficiently, we propose a novel convexification framework based on semidefinite programming (SDP). By analyzing a globally optimal SDP solution, we delineate the "attackable region" for any given set of measurement types and grid topology, where the spurious state can be falsified by FDIA. Furthermore, we prove that the attack is stealthy and sparse, and derive performance bounds. Simulation results on various IEEE test cases indicate the efficacy of the proposed convexification approach. From the grid protection point of view, the results of this study can be used to design a security metric for the current practice against cyber attacks, redesign the bad data detection scheme, and inform proposals of grid hardening. From a theoretical point of view, the proposed framework can be used for other nonconvex problems in power systems and beyond.

  • 270.
    Johansson, Alexander
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Reglerteknik.
    Nekouei, Ehsan
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Reglerteknik.
    Johansson, Karl Henrik
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Reglerteknik.
    Mårtensson, Jonas
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Reglerteknik.
    Multi-Fleet Platoon Matching: A Game-Theoretic Approach2018Inngår i: 2018 21ST INTERNATIONAL CONFERENCE ON INTELLIGENT TRANSPORTATION SYSTEMS (ITSC), IEEE , 2018, s. 2980-2985Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We consider the platoon matching problem for a set of trucks with the same origin, but different destinations. It is assumed that the vehicles benefit from traveling in a platoon for instance through reduced fuel consumption. The vehicles belong to different fleet owners and their strategic interaction is modeled as a non-cooperative game where the vehicle actions are their departure times. Each truck has a preferred departure time and its utility function is defined as the difference between its benefit from platooning and the cost of deviating from its preferred departure time. We show that the platoon matching game is an exact potential game. An algorithm based on best response dynamics is proposed for finding a Nash equilibrium of the game. At a Nash equilibrium, vehicles with the same departure time are matched to form a platoon. Finally, the total fuel reduction at the Nash equilibrium is studied and compared with that of a cooperative matching solution where a common utility function for all vehicles is optimized.

  • 271.
    Johansson, Alexander
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Wei, Jieqiang
    KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Sandberg, Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Johansson, Karl H.
    KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Chen, J.
    Optimization of the H∞-norm of Dynamic Flow Networks2018Inngår i: 2018 Annual American Control Conference (ACC), Institute of Electrical and Electronics Engineers (IEEE), 2018, s. 1280-1285Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, we study the H∞-norm of linear systems over graphs, which is used to model distribution networks. In particular, we aim to minimize the H∞-norm subject to allocation of the weights on the edges. The optimization problem is formulated with LMI (Linear-Matrix-Inequality) constraints. For distribution networks with one port, i.e., SISO systems, we show that the H∞-norm coincides with the effective resistance between the nodes in the port. Moreover, we derive an upper bound of the H∞-norm, which is in terms of the algebraic connectivity of the graph on which the distribution network is defined.

  • 272.
    Johansson, Björn
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Keviczky,, T.
    Johansson, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Johansson, Karl Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Subgradient methods and consensus algorithms for solving convex optimization problems2008Inngår i: Decision and Control, 2008. CDC 2008. 47th IEEE Conference on, IEEE , 2008, s. 4185-4190Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper we propose a subgradient method for solving coupled optimization problems in a distributed way given restrictions on the communication topology. The iterative procedure maintains local variables at each node and relies on local subgradient updates in combination with a consensus process. The local subgradient steps are applied simultaneously as opposed to the standard sequential or cyclic procedure. We study convergence properties of the proposed scheme using results from consensus theory and approximate subgradient methods. The framework is illustrated on an optimal distributed finite-time rendezvous problem.

    Fulltekst (pdf)
    multiagent_cdc08
  • 273. Johansson, Björn
    et al.
    Speranzon, A.
    Johansson, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Johansson, Karl H.
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    On decentralized negotiation of optimal consensus2008Inngår i: Automatica, ISSN 0005-1098, E-ISSN 1873-2836, Vol. 44, nr 4, s. 1175-1179Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A consensus problem consists of finding a distributed control strategy that brings the state or output of a group of agents to a common value, a consensus point. In this paper, we propose a negotiation algorithm that computes an optimal consensus point for agents modeled as linear control systems subject to convex input constraints and linear state constraints. By primal decomposition and incremental subgradient methods, it is shown that the algorithm can be implemented such that each agent exchanges only a small amount of information per iteration with its neighbors.

    Fulltekst (pdf)
    multiagent_automatica08
  • 274.
    Johansson, Björn
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Speranzon, Alberto
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Johansson, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Johansson, Karl Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Distributed Model Predictive Consensus2006Inngår i: Proceedings of the 17th International Symposium on Mathematical Theory of Networks and Systems, 2006, s. 2438-2444Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper we consider the problem of designing a distributed control strategy such that a linear combination of the states of a number of vehicles coincide at a given time. The vehicles are described by linear difference equations and are subject to convex input constraints. It is demonstrated how primal decomposition techniques and incremental subgradient methods allow us to find a solution in which each vehicle performs individual planning of its trajectory and exchanges critical information with neighbors only. We explore various communication, computation, and control structures, and demonstrate the performance of the algorithms by numerical examples.

    Fulltekst (pdf)
    fulltext
  • 275.
    Johansson, Karl H.
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Cyber-physical control of road freight transport2016Inngår i: 2016 IEEE INTERNATIONAL CONFERENCE ON AUTONOMIC COMPUTING (ICAC) / [ed] Kounev, S Giese, H Liu, J, IEEE, 2016, s. 4-4Konferansepaper (Fagfellevurdert)
  • 276.
    Johansson, Karl H.
    Department of Electrical Engineering & Computer Sciences, University of California, Berkeley, CA.
    Interaction bounds in multivariable control systems1999Konferansepaper (Fagfellevurdert)
    Fulltekst (pdf)
    zero_ifac99
  • 277.
    Johansson, Karl H.
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Interaction bounds in multivariable control systems2002Inngår i: Automatica, ISSN 0005-1098, E-ISSN 1873-2836, Vol. 38, nr 6, s. 1045-1051Artikkel i tidsskrift (Fagfellevurdert)
    Fulltekst (pdf)
    mimo_zero_automat02
  • 278.
    Johansson, Karl H.
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Barabanov, A.
    Astrom, K. J.
    Limit cycles with chattering in relay feedback systems1997Konferansepaper (Fagfellevurdert)
  • 279.
    Johansson, Karl H.
    et al.
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Barabanov, A. E.
    Astrom, K. J.
    Limit cycles with chattering in relay feedback systems2002Inngår i: IEEE Transactions on Automatic Control, ISSN 0018-9286, E-ISSN 1558-2523, Vol. 47, nr 9, s. 1414-1423Artikkel i tidsskrift (Fagfellevurdert)
    Fulltekst (pdf)
    relay_ac02
  • 280. Johansson, Karl H.
    et al.
    Horch, Alexander
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Wijk, Olle
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Hansson, Anders
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Teaching multivariable control using the Quadruple-Tank Process1999Inngår i: Proceedings of the 38th IEEE Conference on Decision and Control, 1999, IEEE , 1999, s. 807-812Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A multivariable laboratory process is presented together with its use in a graduate control course. The process is called the quadruple-tank process and demonstrates a multivariable level control problem. The multivariable zero dynamics of the system can be made both minimum phase and nonminimum phase by simply changing a valve. This makes the quadruple-tank process suitable for illustrating many concepts in linear and nonlinear multivariable control. In the paper some of these are described together with the basic setup of the process. Two computer exercises and one laboratory exercise have been developed as part of a course in multivariable and nonlinear control. These are detailed and some experience from the course is presented.

    Fulltekst (pdf)
    quadtank_cdc99
  • 281.
    Johansson, Karl H.
    et al.
    Department of EECS, University of California.
    Hägglund, Tore
    Department of Automatic Control, Lund University.
    Control structure design in process control systems2000Konferansepaper (Fagfellevurdert)
    Fulltekst (pdf)
    adchem00
  • 282. Johansson, Karl H.
    et al.
    James, B.
    Bryant, G. F.
    Astrom, K. J.
    Multivariable controller tuning1998Inngår i: Proceedings of the American Control Conference, 1998, IEEE , 1998, s. 3514-3518Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The problem of tuning individual loops in a multivariable controller is investigated. It is shown how the performance of a specific loop relates to a row in the controller matrix. Several interpretations of this relation are given. An algorithm is also presented that estimates the model required for the tuning via a relay feedback experiment. The algorithm does not need any prior information about the system or the controller. The results are illustrated by an example.

    Fulltekst (pdf)
    multituning_acc98
  • 283. Johansson, Karl H.
    et al.
    Lygeros, J.
    Sastry, S.
    Egerstedt, Magnus
    Simulation of Zeno hybrid automata1999Inngår i: Proceedings of the 38th IEEE Conference on Decision and Control, 1999, IEEE , 1999, s. 3538-3543Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Zeno hybrid automata are hybrid systems that can exhibit infinitely many discrete transitions in a finite time interval. Such automata arise due to modeling simplifications and may deteriorate simulation efficiency and accuracy considerably. Some basic properties of Zeno hybrid automata are explored. Possible ways to extend a simulation beyond the Zeno time are suggested

    Fulltekst (pdf)
    zeno_simul_cdc99
  • 284.
    Johansson, Karl H.
    et al.
    Department of Automatic Control, Lund Institute of Technology.
    Nunes, J. L. R.
    Department of Informatics, University of Coimbra, Portugal.
    A multivariable laboratory process with an adjustable zero1998Inngår i: Proceedings of the American Control Conference, Philadelphia, Pennsylvania June 1998, AACC , 1998, s. 2045-2049Konferansepaper (Fagfellevurdert)
    Abstract [sv]

    A novel multivariable laboratory process that consists of four interconnected water tanks is presented. The linearized dynamics of the system have a multivariable zero that is possible to move along the real axis by changing a valve. The zero can be placed in both the left and the right half-plane. In this way the quadruple-tank process is ideal for illustrating many concepts in multivariable control, particularly performance limitations due to multivariable right half-plane zeros. Accurate models are derived from both physical and experimental data and multi-loop control is illustrated.

    Fulltekst (pdf)
    quadtank_acc98
  • 285.
    Johansson, Karl H.
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Pappas, George J.
    Tabuada, Paulo
    Tomlin, Claire J.
    Special Issue on Control of Cyber-Physical Systems2014Inngår i: IEEE Transactions on Automatic Control, ISSN 0018-9286, E-ISSN 1558-2523, Vol. 59, nr 12, s. 3120-3121Artikkel i tidsskrift (Annet vitenskapelig)
  • 286.
    Johansson, Karl Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Automation and vehicular applications of networked control2008Konferansepaper (Fagfellevurdert)
  • 287.
    Johansson, Karl Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Book review of Relay Feedback by Wang et al2007Inngår i: Control Systems Magazine, ISSN 0272-1708, Vol. 27, nr 3, s. 101-103Artikkel i tidsskrift (Annet vitenskapelig)
    Fulltekst (pdf)
    IEEE Control Systems Magazine
  • 288.
    Johansson, Karl Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Discussion on: "Stabilization of networked control system with time delays and data-packet losses"2007Inngår i: European Journal of Control, ISSN 0947-3580, E-ISSN 1435-5671, Vol. 13, nr 4, s. 353-355Artikkel i tidsskrift (Annet vitenskapelig)
  • 289.
    Johansson, Karl Henrik
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Hybrid control systems2004Inngår i: UNESCO Encyclopedia of Life Support Systems (EOLSS), Unesco, 2004Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Most practical control systems involve both analogue and logic components. Hybrid control system is a generic term for such systems, where the continuous and the discrete dynamics are interacting. These systems arise naturally in many applications of automatic control, for example when a physical plant is controlled by a finite set of controls. Hybrid systems is a recent and very active research area, which evolves from the foundations of control theory and computer science. The developed framework is suitable for the design of complex embedded and networked control systems, which are often hard to analyze with traditional tools. Here a brief introduction to hybrid control is presented and the EOLSS articles under hybrid control systems are put into context.

    Fulltekst (pdf)
    eolss_6.43.28
  • 290.
    Johansson, Karl Henrik
    Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA.
    The Quadruple-Tank Process-A multivariable laboratory process with an adjustable zero2000Inngår i: IEEE Transactions on Control Systems Technology, ISSN 1063-6536, E-ISSN 1558-0865, Vol. 8, nr 3, s. 456-465Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A multivariable laboratory process that consists of four interconnected water tanks is presented. The linearized dynamics of the system have a multivariable zero that is possible to move along the real axis by changing a valve. The zero can be placed in both the left and the right half-plane. In this way the quadruple-tank process is ideal for illustrating many concepts in multivariable control, particularly performance limitations due to multivariable right half-plane zeros. The location and the direction of the zero have an appealing physical interpretation. Accurate models are derived from both physical and experimental data and decentralized control is demonstrated on the process.

    Fulltekst (pdf)
    quadtank_ieeecst00
  • 291.
    Johansson, Karl Henrik
    et al.
    University of California, Berkeley.
    Egerstedt, Magnus
    KTH.
    Lygeros, J.
    University of California, Berkeley.
    Sastry, S.
    University of California, Berkeley.
    On the regularization of Zeno hybrid automata1999Inngår i: Systems & control letters (Print), ISSN 0167-6911, E-ISSN 1872-7956, Vol. 38, nr 3, s. 141-150Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Fundamental properties of hybrid automata, such as existence and uniqueness of executions, are studied. Particular attention is devoted to Zeno hybrid automata, which are hybrid automata that take infinitely many discrete transitions in finite time. It is shown that regularization techniques can be used to extend the Zeno executions of these automata to times beyond the Zeno time. Different types of regularization may, however, lead to different extensions. A water tank control problem and a bouncing ball system are used to illustrate the results.

    Fulltekst (pdf)
    zeno_scl99
  • 292.
    Johansson, Karl Henrik
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Lygeros, J.
    Sastry, S.
    Zhang, J.
    Hybrid automata: A formal paradigm for heterogeneous modeling2000Konferansepaper (Fagfellevurdert)
  • 293.
    Johansson, Karl Henrik
    et al.
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Lygeros, John
    Sastry, Shankar
    Modeling of hybrid systems2004Inngår i: Encyclopedia of Life Support Systems (EOLSS), Theme 6.43: Control Systems, Robotics and Automation, Unesco, 2004Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    The distinguishing characteristic of hybrid systems is the interaction between a continuous-time and a discrete-event component. By modeling these different components using differential equations and finite state automata, it is possible to represent a wide range of phenomena present in physical and technological systems. This paper illustrates hybrid dynamics by several simple examples. Some of these examples illustrate properties of hybrid systems not present in purely continuous or purely discrete systems, while others illustrate application domains such as vehicle control and real-time systems. A mathematical model called a hybrid automaton is then introduced, to show how hybrid dynamics can be formally analyzed.

    Fulltekst (pdf)
    eolss_6.43.28.1
  • 294. Johansson, Karl Henrik
    et al.
    Rantzer, A.
    Decentralized control of sequentially minimum phase systems1999Inngår i: IEEE Transactions on Automatic Control, ISSN 0018-9286, E-ISSN 1558-2523, Vol. 44, nr 10, s. 1909-1913Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Fundamental limitations in decentralized control of systems with multivariable zeros are considered. It is shown that arbitrary bandwidth can be obtained with a stable block-diagonal controller, if certain subsystems of the open-loop system fail to have zeros in the right half-plane and a high-frequency condition holds. Implications on control structure design and sequential loop-closuring methods are discussed.

    Fulltekst (pdf)
    seq_mph_ac99
  • 295. Johansson, Karl Henrik
    et al.
    Rantzer, A.
    Global analysis of third-order relay feedback systems1996Konferansepaper (Fagfellevurdert)
  • 296. Johansson, Karl Henrik
    et al.
    Rantzer, A.
    Multi-loop control of minimum phase processes1997Konferansepaper (Fagfellevurdert)
  • 297. Johansson, Karl Henrik
    et al.
    Rantzer, Anders
    Ås ström", Karl Johan
    Fast switches in relay feedback systems1999Inngår i: Automatica, ISSN 0005-1098, E-ISSN 1873-2836, Vol. 35, nr 4, s. 539-552Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Relays are common in automatic control systems. Even linear systems with relay feedback are, however, far from fully understood. New results are given about the behavior of these systems via a state-space approach. It is proved that there exist multiple fast switches if and only if the sign of the first nonvanishing Markov parameter of the linear system is positive. Fast switches are shown to occur as part of stable limit cycles. An analysis is developed for these limit cycles that illustrates how they can be predicted.

    Fulltekst (pdf)
    relay_automatica99
  • 298.
    Johansson, Karl Henrik
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Santucci, Fortunato
    On hybrid control problems in communication systems2005Inngår i: Proceedings of the 44th IEEE Conference on Decision and Control, and the European Control Conference 2005, IEEE , 2005, s. 5624-5629Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The importance of a strong research agenda on the convergence of communications and control has been emphasized by several researchers recently. The purpose of this paper is to evidence through concrete application examples how the envisioned synergy can actually be exploited. The focus is on control of wireless communication networks. In order to address in a rigorous and exhaustive way the complexity of interactions that usually arise in these systems, we try to devise how hybrid modelling may intrinsically provide a theoretical framework to formulate problems and provide partial solutions.

    Fulltekst (pdf)
    network_hycon_cdc05
  • 299.
    Johansson, Karl Henrik
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Speranzon, Alberto
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Zampieri, S.
    On quantization and communication topologies in multi-vehicle rendezvous2005Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A rendezvous problem for a team of autonomous vehicles that is communicating through quantized channels is considered. Communication topologies and feedback control law are presented that solves the rendezvous problem in the sense that a meeting point for the vehicles is practically stabilized. In particular, it is shown that uniform quantizers can sometimes be replaced by logarithmic quantizers and thus reduce the need for communication bandwidth.

    Fulltekst (pdf)
    multirobot_ifac05
  • 300.
    Johansson, Karl Henrik
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Törngren, Martin
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Inbyggda styrsystem.
    Nielsen, Lars
    Linköping University.
    Vehicle Applications of Controller Area Network2005Inngår i: HANDBOOK OF NETWORKED AND EMBEDDED CONTROL SYSTEMS / [ed] Dimitrios Hristu-Varsakelis and William S. Levine, Springer, 2005, s. 741-765Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    The Controller Area Network (CAN) is a serial bus communications protocol developed by Bosch in the early 1980s. It defines a standard for efficient and reliable communication between sensor, actuator, controller, and other nodes in real-time applications. CAN is the de facto standard in a large variety of networked embedded control systems. The early CAN development was mainly supported by the vehicle industry: CAN is found in a variety of passenger cars, trucks, boats, spacecraft, and other types of vehicles. The protocol is also widely used today in industrial automation and other areas of networked embedded control, with applications in diverse products such as production machinery, medical equipment, building automation, weaving machines, and wheelchairs.The purpose of this chapter is to give an introduction to CAN and some of its vehicle applications. The outline is as follows. Section 2 describes the CAN protocol, including its message formats and error handling. The section is concluded by a brief history of CAN. Examples of vehicle application architectures based on CAN are given in Section 3. A few specific control loops closed over CAN buses are discussed in Section 4. The paper is concluded with some perspectives in Section 5, where current research issues such as x-by-wire and standardized software architectures are considered. The examples are described in more detail in [14]. A detailed description of CAN is given in the textbook [6]. Another good resource for further information is the homepage of the organization CAN-in-Automation (CiA) [3]. The use of CAN as a basis for distributed control systems is discussed in [13].

    Fulltekst (pdf)
    fulltext
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