| 1. |
- Birk, Wolfgang, et al.
(författare)
-
Road surface networks technology enablers for enhanced ITS
- 2010
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Ingår i: 2010 IEEE Vehicular Networking Conference, VNC 2010. - Piscataway, NJ : IEEE Communications Society. - 9781424495269 ; , s. 152-159
-
Konferensbidrag (refereegranskat)abstract
- The increased need for mobility has led to transportation problems like congestion, accidents and pollution. In order to provide safe and efficient transport systems great efforts are currently being put into developing Intelligent Transport Systems (ITS) and cooperative systems. In this paper we extend proposed solutions with autonomous on-road sensors and actuators forming a wireless Road Surface Network (RSN). We present the RSN architecture and design methodology and demonstrate its applicability to queue-end detection. For the use case we discuss the requirements and technological solutions to sensor technology, data processing and communication. In particular the MAC protocol is detailed and its performance assessed through theoretical verification. The RSN architecture is shown to offer a scalable solution, where increased node density offers more precise sensing as well as increased redundancy for safety critical applications. The use-case demonstrates that RSN solutions may be deployed as standalone systems potentially integrated into current and future ITS. RSN may provide both easily deployable and cost effective alternatives to traditional ITS (with a direct impact independent of penetration rate of other ITS infrastructures - i.e., smart vehicles, safe spots etc.) as well as provide fine grain sensory information directly from the road surface to back-end and cooperative systems, thus enabling a wide range of ITS applications beyond current state of the art.
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| 2. |
- Alhashimi, Anas, 1978-
(författare)
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The application of auto regressive spectrum modeling for identification of the intercepted radar signal frequency modulation
- 2012
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Ingår i: Inventi Impact - Telecom. - Bhopal, India : Inventi Journals Pvt.Ltd.. - 2249-1414 .- 2230-8172. ; 2012:3
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Tidskriftsartikel (refereegranskat)abstract
- In the Electronic Warfare receivers, it is important to know the type of modulation of the intercepted Radar signals (MOP modulation on pulse). This information can be very helpful in identifying the type of Radar present and to take the appropriate actions against it. In this paper, a new signal processing method is presented to identify the FM (Frequency Modulation) pattern from the received Radar pulses. The proposed processing method based on Auto Regressive Spectrum Modelling used for digital modulation classification [1]. This model uses the instantaneous frequency and instantaneous bandwidth as obtained from the roots of the autoregressive polynomial. The instantaneous frequency and instantaneous bandwidth together were used to identify the type of modulation in the Radar pulse. Another feature derived from the instantaneous frequency is the frequency rate of change. The frequency rate of change was used to extract the pattern of the frequency change. Results show that this method works properly even for low signal to noise ratios.
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| 3. |
- Stigwall, Johan, 1977, et al.
(författare)
-
Photonic GHz to THz tunable signal generation by chirped-pulse mixing
- 2006
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Ingår i: 2006 European ISIS Workshop, Emerging Optical Broadband Technologies, Boppard am Rhein, Germany, May 29 - June 1, 2006.
-
Konferensbidrag (refereegranskat)abstract
- Frequency-tunable generation of pulsed tones in the millimeter to sub-millimeter range was demonstrated by mixing of two chromatically dispersing femtosecond laser pulses split up in time by an adjustable differential group delay (DGD) and a polarizer. The signal frequency was set by adjusting the amount of DGD and the amount of dispersion, and was here tuned from below 1 GHz to 0.9 THz. Time-domain measurements were conducted using a sampling oscilloscope for the lower frequencies and an auto-correlator for the higher frequencies. Near 100% modulation depth was obtained, and the signal phase was very stable, being locked to the pulses from the femtosecond laser. The line-width of the mm-wave waveform was found to be transform-limited if the signal chirp induced by higher order dispersion was compensated for. Suggested applications for this system are for instance THz spectroscopy, characterization of high performance photo-diodes and real-time dispersion measurements.
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| 4. |
- Ribeiro, Luis, et al.
(författare)
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Industrial Agents for the Fast Deployment of Evolvable Assembly Systems
- 2015. - 1st ed.
-
Ingår i: Industrial Agents. - Amsterdam, Netherlands : Elsevier. - 9780128003411 ; , s. 301-321, s. 301-322
-
Bokkapitel (refereegranskat)abstract
- The current manufacturing scenario is characterized by high market unpredictability. Agility is therefore a central challenge for modern companies that need to understand and be proactive towards their product offer in respect to “what is offered, when it is offered, where, how and by whom” (Brown & Bessant 2003).The “what” and the “when” are particularly relevant to the research in emerging paradigms as they account for variety, customization and volume; and timing, speed and seasonality (Brown & Bessant 2003).In this scenario, several design approaches and models have been proposed in the last decade to enable re-configurability and subsequently enhance the companies’ ability to adjust their offer in nature and time.From a paradigmatic point of view research has concentrated on the organizational structure of the shop-floor and the associated controls aspects. Concepts like Reconfigurable Manufacturing Systems (RMS) (Koren & Shpitalni 2010) and Fractal Factories (FF) (Montreuil 1999) support the physical construction of production systems by regulating their layout and making a few assumptions on their logical organization. On the other hand, concepts like Bionic Manufacturing Systems (BMS)(Ueda 1992), Holonic Manufacturing Systems (HMS)(Van Brussel et al. 1998), Evolvable Assembly Systems (Ribeiro et al. 2010) essentially provide the theoretical guidelines for the logical/computational organization of the system (see (Tharumarajah 1996) for a comparison between BMS, HMS and FF and (Setchi & Lagos 2004) for the rationale supporting the shift from Dedicated Lines to Flexible Manufacturing System and finally RMS).While these paradigms provide the conceptual framework and the main design guidelines their actual interpretation and implementation has led to a wider set of architectures (Monostori, Váncza & Kumara 2006; Leitão 2009; Parunak 2000; Pěchouček & Mařík 2008).These architectures align the high-level principles with the technological offer and limitations while seeking to address the re-configurability requirements of (Mehrabi, Ulsoy & Koren 2000; Rösiö & Säfsten 2013):module mobility – modules are easy and quick to move and install;“diagnosability” – it is quick to identify the sources of quality and reliability problems;“integrability” – modules are easy to integrate into the rest of the system.“convertibility” – it is easy and quick to switch between existing products and it is easy to adapt the system to future products;scalability – it is easy to enlarge and downsize the production system;“automatibility” – a dynamic level of automation is enabled;modularity – all system elements are designed to be modular;customization – the capability and flexibility of the production system is designed according to the products to be produced in the system.Instant deployment, as addressed in the present chapter directly addresses mobility, “integrability”, “convertibility”, scalability and customization. Mechatronic modularity is a prerequisite and is enforced by the proposed architecture and the considered modular design. “Diagnosability” was not specifically tackled.In this context, the chapter analyses the agent-based architecture related with the Instantly Deployable Evolvable Assembly System (IDEAS) project that is inspired by the Evolvable Assembly System (EAS) paradigm (Ribeiro et al. 2010) as a mechanism to enable fast deployment of mechatronic modules. EAS advocates the use of process-oriented modules and envisions the production system as a collection of processes and the associated interacting agents.The architecture and the related test cases are used to draw the main lessons learned in respect to technological and conceptual implications.In this context, the remainder of this text is organized as follows: section 1.1 discusses the main deployment challenges, section 1.2 details the reference architecture and associated concepts, section 1.3 presents the principal implementation decisions, section 1.4 features the main lessons learned, sections 1.5 discusses the benefits of the proposed approach and finally section 1.6 reflects on the main conclusions.
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| 5. |
- Birk, Wolfgang, et al.
(författare)
-
Project: iRoad
- 2011
-
Annan publikation (populärvet., debatt m.m.)
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| 6. |
- Carlson, Johan, et al.
(författare)
-
Projekt: SCOPE Norra
- 2011
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Annan publikation (populärvet., debatt m.m.)abstract
- SCOPE Norra är ett samarbetskonsortium för forskning och utveckling tillsammans med massa- och pappersindustrin i Norrbotten och Västerbotten. Projektet koordineras av centrumbildningen ProcessIT Innovations.Inom SCOPE Norra pågår ett flertal delprojekt, uppdelat på ett antal fokusområden.Huvudfinansiär för konsortiet är Tillväxtverket genom medel från EU:s strukturfonder.
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| 7. |
- Di Orio, Giovanni, et al.
(författare)
-
The PRIME Semantic Language: Plug and Produce in Standard- based Manufacturing Production Systems
- 2015
-
Ingår i: Proceedings of the Flexible Automation and Intelligent Manufacturing Conference.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Nowadays manufacturing production systems are becoming more and more responsive in order to succeed in ahighly unstable environment. The capability of a production system to effectively and efficiently adapt and evolveto face the changing requirements – imposed by volatile and dynamic global markets – is a necessary conditionto enable manufacturing enterprises to be agile. Since the agility of a manufacturing enterprise is always limitedby the agility of its own building blocks than it needs to be spread over the whole enterprise including the operationand information technologies (OT/IT). Turning to production systems, one of the significant challenges isrepresented by the possibility to provide easy and rapid (re-)configuration of their internal components and/orprocesses. Innovative technologies and paradigms have been explored during the years that combined with theincreasing advancement in manufacturing technologies enable the implementation of the “plug and produce”paradigm. The “plug and produce” paradigm is the foundation of any agile production system, since to be agile itis inevitably required to reduce the installation and (re-)engineering activities time – changing/adapting the systemto new requirements – while promoting configuration rather than programming. Therefore, the “plug andproduce” paradigm is a necessary but not sufficient condition for implementing agile production systems. Modernproduction systems are typically known for their plethora of heterogeneous component/equipment. In this complexscenario, the implementation of the “plug and produce” paradigm implies the existence of a well-definedontological model to support components/equipment abstraction with the objective to allow interactions,collaboration and knowledge sharing between them. The PRIME semantic language specifies the semanticstructure for the knowledge models and overall system communication language.
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| 8. |
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| 9. |
- Haasl, Sjoerd, et al.
(författare)
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Hybrid mounted micromachined aluminium hot-wire for near-wall turbulence measurements
- 2002
-
Ingår i: FIFTEENTH IEEE INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS. - : IEEE. - 0780371852 ; , s. 336-339
-
Konferensbidrag (refereegranskat)abstract
- We present the first micromachined metal hot-wire anemometer sensor for use in near-wall turbulence measurements. To measure close to the surface without the circuitry interfering with the flow, a novel hybrid assembly of the sensor has been developed. We present the design, fabrication and characteristics of this sensor.
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| 10. |
- Satpute, Sumeet G., 1987-, et al.
(författare)
-
Optimization Based Safe and Efficient Trajectory Planning in Proximity of an Asteroid
- 2020
-
Ingår i: 2020 7th International Conference on Control, Decision and Information Technologies (CoDIT). - : IEEE. ; , s. 939-945
-
Konferensbidrag (refereegranskat)abstract
- This article focuses on a spacecraft trajectory planning algorithm that allows observation of multiple site locations on the asteroid surface, while avoiding any collision with debris objects trapped in the asteroid’s gravity field. Asteroids provide a challenging target for satellite based visual coverage missions, since they are partially illuminated, rotating, irregular shaped celestial bodies with a low but also irregular gravity field. For addressing this problem, an optimization approach for visual coverage is proposed with an objective to determine the sequence of the imaging site locations and the associated safe and fuel efficient trajectories, while considering rotational dynamics of the asteroid, changing illumination condition for each site, irregular gravity constraints of the asteroid and the safe separation distance from the moving debris object. Numerical simulations are performed to demonstrate the ability of the trajectory planner to ensure successful optimal coverage of all the desired asteroid site locations.
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| 11. |
- Abbaspour Asadollah, Sara, et al.
(författare)
-
Evaluation of surface EMG-based recognition algorithms for decoding hand movements
- 2019
-
Ingår i: Medical and Biological Engineering and Computing. - : Springer. - 0140-0118 .- 1741-0444. ; 58:1, s. 83-100
-
Tidskriftsartikel (refereegranskat)abstract
- Myoelectric pattern recognition (MPR) to decode limb movements is an important advancement regarding the control of powered prostheses. However, this technology is not yet in wide clinical use. Improvements in MPR could potentially increase the functionality of powered prostheses. To this purpose, offline accuracy and processing time were measured over 44 features using six classifiers with the aim of determining new configurations of features and classifiers to improve the accuracy and response time of prosthetics control. An efficient feature set (FS: waveform length, correlation coefficient, Hjorth Parameters) was found to improve the motion recognition accuracy. Using the proposed FS significantly increased the performance of linear discriminant analysis, K-nearest neighbor, maximum likelihood estimation (MLE), and support vector machine by 5.5%, 5.7%, 6.3%, and 6.2%, respectively, when compared with the Hudgins’ set. Using the FS with MLE provided the largest improvement in offline accuracy over the Hudgins feature set, with minimal effect on the processing time. Among the 44 features tested, logarithmic root mean square and normalized logarithmic energy yielded the highest recognition rates (above 95%). We anticipate that this work will contribute to the development of more accurate surface EMG-based motor decoding systems for the control prosthetic hands. [Figure not available: see fulltext.].
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| 12. |
- del Aguila Pla, Pol, 1990-, et al.
(författare)
-
Clock synchronization over networks - Identifiability of the sawtooth model
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, we analyze the two-node joint clocksynchronization and ranging problem. We focus on the case of nodes that employ time-to-digital converters to determine the range between them precisely. This specific design leads to a sawtooth model for the captured signal, which has not been studied in detail before from an estimation theory standpoint. In the study of this model, we recover the basic conclusion of a well-known article by Freris, Graham, and Kumar in clock synchronization. Additionally, we discover a surprising identifiability result on the sawtooth signal model: noise improves the theoretical condition of the estimation of the phase and offset parameters. To complete our study, we provide performance references for joint clock synchronization and ranging. In particular, we present the Cramér-Rao lower bounds that correspond to a linearization of our model, as well as a simulation study on the practical performance of basic estimation strategies under realistic parameters. With these performance references, we enable further research in estimation strategies using the sawtooth model and pave the path towards industrial use.
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| 13. |
- Eriksson, Martin, et al.
(författare)
-
Monitoring and modelling open compute servers
- 2017
-
Ingår i: Proceedings IECON 2017 - 43rd Annual Conference of the IEEE Industrial Electronics Society. - Piscataway, NJ : Institute of Electrical and Electronics Engineers Inc.. - 9781538611272 ; , s. 7177-7184, s. 7177-7184
-
Konferensbidrag (refereegranskat)abstract
- Energy efficient control of server rooms in modern data centers can help reducing the energy usage of this fast growing industry. Efficient control, however, cannot be achieved without: i) continuously monitoring in real-time the behavior of the basic thermal nodes within these infrastructures, i.e., the servers; ii) analyzing the acquired data to model the thermal dynamics within the data center. Accurate data and accurate models are indeed instrumental for implementing efficient data centers cooling strategies. In this paper we focus on a class of Open Compute Servers, designed in an open-source fashion and currently deployed by Facebook. We thus propose a set of methods for collecting real-time data from these platforms and a control-oriented model describing the thermal dynamics of the CPUs and RAMs of these servers as a function of both manipulable and exogenous inputs (e.g., the CPU utilization levels and the air mass flow produced by the server's fans). We identify the parameters of this model from real data and make the results available to other researchers.
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| 14. |
- Kersten, Anton, 1991, et al.
(författare)
-
Battery Loss and Stress Mitigation in a Cascaded H-Bridge Multilevel Inverter for Vehicle Traction Applications by Filter Capacitors
- 2019
-
Ingår i: IEEE Transactions on Transportation Electrification. - 2332-7782. ; 5:3, s. 659-671
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, two types of filter capacitors of varying capacity, were connected to the battery packs of a cascaded H-Bridge single-star multilevel vehicle traction inverter, and their influence on the battery losses has been analyzed. The battery and capacitor simulation models used are experimentally verified in a down-scaled system. Different capacitor configurations were simulated for four drive cycle scenarios to determine the potentials for the mitigation of current pulse stresses and battery loss reduction with respect to the added weight. By adding capacitors corresponding to a weight of 4% of the initial battery storage, the peak current is reduced by 5%-20%, depending on the operating point from DC to a few kHz, and the battery losses are reduced by 10%. In comparison, it is demonstrated that adding supercapacitors is more beneficial for lower output frequencies, while adding electrolytic capacitors is better for higher output frequencies. Furthermore, the low-order voltage harmonics of the DC-rails between the converter and battery were reduced by 10%-30% for frequencies above 9 kHz, which decreases the potential of electromagnetic disturbances. In addition, during cold battery temperatures, when it is very important to avoid heavy cyclings, the loss reduction using the capacitors was 2.5 times larger than for nominal temperature.
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| 15. |
- Kersten, Anton, 1991, et al.
(författare)
-
Fault Detection and Localization for Limp Home Functionality of Three-Level NPC Inverters with Connected Neutral Point for Electric Vehicles
- 2019
-
Ingår i: IEEE Transactions on Transportation Electrification. - 2332-7782. ; 5:2, s. 416-432
-
Tidskriftsartikel (refereegranskat)abstract
- This paper deals with the detection of single battery or inverter switch faults during operation of a common and an active three-level neutral-point-clamped (NPC) inverter with a connected neutral point. Here, the main focus lies on the detection and localization of open-circuit faults of the inverter's switches. Therefore, a fault detection algorithm, using a current estimator, and two fault localization algorithms, a pulse pattern injection principle and an online adaption of the space vector modulation (SVM), are investigated and verified through simulations and experiments. Also, investigated is how the powertrain can be operated under a fault condition, so that the vehicle can drive with a limited maximum power using an adapted SVM, referred to as "limp home" mode, to the next service station. It is shown, that an active NPC inverter can cope with any single short or open-circuit fault of the inverter's switches without bringing the vehicle to standstill, whereas a generic NPC inverter loses controllability if an open-circuit fault at an inner switch occurs. Furthermore, both inverter types are able to be operated just with half of the dc-link voltage in case of a failure in one part of the battery.
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| 16. |
- Kersten, Anton, 1991, et al.
(författare)
-
Measuring and Separating Conducted Three-Wire Emissions from a Fault-Tolerant, NPC Propulsion Inverter with a Split-Battery Using Hardware Separators Based on HF Transformers
- 2021
-
Ingår i: IEEE Transactions on Power Electronics. - 0885-8993 .- 1941-0107. ; 36:1, s. 378-390
-
Tidskriftsartikel (refereegranskat)abstract
- Conducted emissions on the traction battery's power cables in EVs must be limited to avoid unwanted electromagnetic interference (EMI). When designing an EMI filter, it is advantageous to have information of the common mode (CM) and differential mode (DM) noise levels. This article deals with the measurement and separation of the dc side's three-wire DM/CM noise of a fault-tolerant three-level neutral-point-clamped (NPC) inverter with a split-battery system. Two hardware separators, based on small-circuit highfrequency transformers, were developed to identify the dc side's CM, line-DM, and phase-DM noise levels. Their characterized CM and DM rejection ratios for the frequency range from 150 kHz to 110 MHz are at least -33 and -21 dB, respectively. The separated noise of the NPC inverter was measured, using an inductive load, when operating the inverter with three-level and two-level modulation, resembling normal operation and a possible operation under fault, respectively. A simple three-wire CM model of the used testbed and the DM power module oscillation were derived to validate the separated noise's resonance peaks/valleys. It has been seen that the CM noise is dominant, especially below 10 MHz, except for the power module oscillations. Furthermore, when using the two-level modulation, in the case of a clamping diode fault, the noise levels are increased by about 3 dB.
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| 17. |
- Kersten, Anton, 1991
(författare)
-
Modular Battery Systems for Electric Vehicles based on Multilevel Inverter Topologies - Opportunities and Challenges
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Modular battery systems based on multilevel inverter (MLI) topologies can possibly overcome some shortcomings of two-level inverters when used for vehicle propulsion. The results presented in this thesis aim to point out the advantages and disadvantages, as well as the technical challenges, of modular vehicle battery systems based on MLIs in comparison to a conventional, two-level IGBT inverter drivetrain. The considered key aspects for this comparative investigation are the drive cycle efficiency, the inverter cost, the fault tolerance capability of the drivetrain and the conducted electromagnetic emissions. Extensive experiments have been performed to support the results and conclusions. In this work, it is shown that the simulated drive cycle efficiency of different low-voltage-MOSFET-based, cascaded seven-level inverter types is improved in comparison to a similarly rated, two-level IGBT inverter drivetrain. For example, the simulated WLTP drive cycle efficiency of a cascaded double-H-bridge (CDHB) inverter drivetrain in comparison to a two-level IGBT inverter, when used in a small passenger car, is increased from 94.24% to 95.04%, considering the inverter and the ohmic battery losses. In contrast, the obtained efficiency of a similar rated seven-level cascaded H-bridge (CHB) drivetrain is almost equal to that of the two-level inverter drivetrain, but with the help of a hybrid modulation technique, utilizing fundamental selective harmonic elimination at lower speeds, it could be improved to 94.85%. In addition, the CDHB and CHB inverters’ cost, in comparison to the two-level inverter, is reduced from 342€ to 202€ and 121€, respectively. Furthermore, based on a simple three-level inverter with a dual battery pack, it is shown that MLIs inherently allow for a fault tolerant operation. It is explained how the drivetrain of a neutral point clamped (NPC) inverter can be operated under a fault condition, so that the vehicle can drive with a limited maximum power to the next service station, referred to as limp home mode. Especially, the detection and localization of open circuit faults has been investigated and verified through simulations and experiments. Moreover, it is explained how to measure the conducted emissions of an NPC inverter with a dual battery pack according to the governing standard, CISPR 25, because the additional neutral point connection forms a peculiar three-wire DC source. To separate the measured noise spectra into CM, line-DM and phase-DMquantities, two hardware separators based on HF transformers are developed and utilized. It is shown that the CM noise is dominant. Furthermore, the CM noise is reduced by 3dB to 6dB when operating the inverter with three-level instead of two-level modulation.
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| 18. |
- Kersten, Anton, 1991, et al.
(författare)
-
Online and On-Board Battery Impedance Estimation of Battery Cells, Modules or Packs in a Reconfigurable Battery System or Multilevel Inverter
- 2020
-
Ingår i: IECON Proceedings (Industrial Electronics Conference). - 2162-4704 .- 2577-1647. ; , s. 1884-1891
-
Konferensbidrag (refereegranskat)abstract
- This paper shows two approaches to determine the battery impedance of battery cells or battery modules when used in a reconfigurable battery system (RBS) or in any type of modular multilevel converter (MMC) for electric drive applications. A generic battery model is used and the concepts of the recursive time and frequency-domain parameter extraction, using a current step and an electrochemical impedance spectroscopy, are explained. Thus, it is shown and demonstrated that the balancing current of neighboring cells/modules ,when in parallel operation, can be used, similar to the time-domain parameter extraction utilizing a current step, to determine the battery parameters. Furthermore, it is shown and demonstrated that a part of the inverter can be used as variable AC voltage source to control a sinusoidal current through the motor inductances of the drive train, which can be injected to the inserted battery cells/modules of an adjacent phase to perform an on-board impedance spectroscopy. Using either of the two presented approaches, the individual battery impedances can be easily determined, yielding the state of health (SOH) and the power capability of individual battery cells/modules. Nonetheless, the analyzed approaches were just considered to be applied at machine standstill, which is not suitable for grid-tied applications.
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| 19. |
- Kuder, Manuel, et al.
(författare)
-
Exponential Modular Multilevel Converter for Low Voltage Applications
- 2019
-
Ingår i: 2019 21st European Conference on Power Electronics and Applications, EPE 2019 ECCE Europe. ; , s. 1-11
-
Konferensbidrag (refereegranskat)abstract
- This paper presents the structure and control of a single phase Exponential Modular Multilevel Converter (EMMC), which works as a bidirectional AC/DC converter. In addition to the main H-bridge converter, it uses series connected H-bridges with DC link capacitors. The nominal voltage rating of the capacitors is increased with each module by factor of two. In this manner, the number of output voltage levels exponentially increases with the number of series connected H-bridges. By using low-voltage MOSFETs it is possible to achieve a very high efficiency, especially at partial loading. The high number of voltage levels reduces the output voltage THD, while using a low switching frequency. Thus, the required grid filter size can be substantially reduced. Furthermore, the additional capacitor modules increase the nominal output voltage at the AC side, so that the flow of the active and reactive power can be dynamically adjusted. Therefore, the EMMC could be used, for instance, as a vehicle charger directly connected to the grid.
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| 20. |
- Mao, Yadong, et al.
(författare)
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Decentralized Training of 3D Lane Detection with Automatic Labeling Using HD Maps
- 2023
-
Ingår i: IEEE Vehicular Technology Conference. - 1550-2252.
-
Konferensbidrag (refereegranskat)abstract
- To have competent 3D lane detection for real-world driving, a massive amount of data from all over the world is needed, but data collection and manual annotation are costly and time-consuming. The diversity of data collected by developmental cars might still be limited compared to the data collected by a large fleet of customer cars. Federated learning enables training models on edge without transferring data out of devices. However, training supervised learning tasks at the edge is directly tied to having access to high-quality labels, which is limited at the edge. In this paper, we propose a fully automatic method to generate 3D lane labels at the edge using a pre-recorded HD map to enable the federated training of the 3D lane detection model. As a reference, a semi-automatic method is applied for creating a 3D-lane dataset used as ground truth. Our experimental results show that the model can achieve comparable performance when training on the same dataset in both a centralized and a decentralized manner. And the models trained on semi-automatic labeled datasets slightly outperform those trained on fully-automatically labeled datasets. This study shows that a well-performing 3D lane detection model can be trained in a supervised and fully decentralized manner, and most importantly, data privacy at the edge is guaranteed.
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| 21. |
- Stotsky, Alexander, 1960
(författare)
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Grid Frequency Estimation Using Multiple Model with Harmonic Regressor: Robustness Enhancement with Stepwise Splitting Method
- 2017
-
Ingår i: IFAC-PapersOnLine. - : Elsevier BV. - 2405-8963. ; 50:1, s. 12817-12822
-
Konferensbidrag (refereegranskat)abstract
- Reduction of inertia in electricity networks due to high penetration level of renewable energy sources will require wind turbines to participate in frequency regulation via Active Power Control. The performance of frequency regulation and protection system depends strongly on the performance of network frequency estimation. Fast frequency variations and uncertainties associated with unknown harmonics and measurement noise in the network signals are the main obstacles to performance improvement of frequency estimation with classical zero crossing method, which is widely used in industry. The same uncertainties introduce challenges in model based frequency estimation. These challenges are addressed in this paper within the framework of multiple model with harmonic regressor. Additional challenges associated with computational complexity of matrix inversion algorithms and accuracy of inversion of ill-conditioned matrices in the multiple model are also discussed in the paper. New high order algorithms with reduced computational complexity are presented. Instability mechanism is discovered in Newton-Schulz and Neumann matrix inversion techniques in finite precision implementation environment. A new stepwise splitting method is proposed for elimination of instability and for performance improvement of matrix inversion algorithms in the multiple model. All the results are confirmed by simulations.
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| 22. |
- Theliander, Oskar, et al.
(författare)
-
Battery Modeling and Parameter Extraction for Drive Cycle Loss Evaluation of a Modular Battery System for Vehicles Based on a Cascaded H-Bridge Multilevel Inverter
- 2020
-
Ingår i: IEEE Transactions on Industry Applications. - 0093-9994 .- 1939-9367. ; 56:6, s. 6968-6977
-
Tidskriftsartikel (refereegranskat)abstract
- This article deals with the modeling and the parameterization of the battery packs used in cascaded H-bridge multilevel propulsion inverters. Since the battery packs are intermittently conducting the motor currents, the battery cells are stressed with a dynamic current containing a substantial amount of low-order harmonic components up to a couple of kHz, which is a major difference in comparison to a traditional two-level inverter drive. Different models, such as pure resistive and dynamic RC -networks, are considered to model the energy losses for different operating points (OPs) and driving cycles. Using a small-scale setup, the models’ parameters are extracted using both a low-frequency, pulsed current, and an electrochemical impedance spectroscopy (EIS) sweep. The models are compared against measurements conducted on the small-scale setup at different OPs. Additionally, a drive cycle loss comparison is simulated. The simple resistive model overestimates the losses by about 20% and is, thus, not suitable. The dynamic three-time-constant model, parameterized by a pulsed current, complies with the measurements for all analyzed OPs, especially at low speed, with a maximum deviation of 3.8%. Extracting the parameters using an EIS seems suitable for higher speeds, though the losses for the chosen OPs are underestimated by 1.5%–7.9%.
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| 23. |
- Theliander, Oskar, et al.
(författare)
-
LiFePO4 Battery Modeling and Drive Cycle Loss Evaluation in Cascaded H-Bridge Inverters for Vehicles
- 2019
-
Ingår i: ITEC 2019 - 2019 IEEE Transportation Electrification Conference and Expo. ; June 2019, s. 1-7
-
Konferensbidrag (refereegranskat)abstract
- This paper deals with the modeling and parameterization of LiFeP04batteries when used in cascaded H-bridge multilevel inverter drive systems. Since the battery packs are intermittently conducting the motor currents, the battery cells are stressed with a dynamic current waveform containing a substantial amount of low order harmonic components in the range of a couple of kHz. Different battery models like a pure resistive or different RC networks are considered, to determine the battery losses. Measurements of the voltage drop for a pulsed current of variable frequency and magnitude are done to be able to determine the model parameters. The models are then verified against measurements on a battery pack placed in a small scale multilevel inverter operated at 6 different operating point that are representative for the operation of an electrified vehicle. It is shown that the dynamic model agrees very well with the measurements for all operating points analyzed with a maximum deviation of 4 %. The results are also compared with the commonly used resistive model which overestimates the losses with typically around 20 % for the evaluated points. Simulations of 4 full drive cycles are performed where it is stated that the resistive model always shows about 20 % more losses compared to the 3 time constant model.
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| 24. |
- Bengtsson, Lars, 1963
(författare)
-
Embedded Measurement Systems
- 2013
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The subject of Embedded Measurement Systems (EMS) is the merging of embedded systems and electrical measurement systems. This indicates that EMSs are hardware-software systems dedicated to measuring one or a few physical quantities. Applications are numerous; EMSs measure the temperature in refrigerators, freezers, irons, ovens and automobile combustion engines, they sense vibrations in tilt alarms and game consoles, they measure airflow in engines and ventilation systems, they measure shock impact in crash detectors and are used as shock and temperature loggers for transport goods, they measure air pressure in airplane cabins, humidity in air-conditioned environments, they measure liquid levels in fuel tanks, they detect smoke in fire alarms, they measure the viscosity of lubricant oil in engines, they measure the rotation speed of spinning wheels (in any engine), they measure torque in engines and are used as heart rate and ECG detectors in medicine etc. The commercial demand for ever cheaper products and worldwide environmental legislations force vendors to continuously look for more cost-efficient and less power-consuming solutions for their embedded measurement systems. This thesis is concerned most of all with the implementation of cost-efficient/low-power measurement systems in embedded controllers. This includes some novel ideas in voltage, time and resistance measurements with embedded controllers and it will demonstrate how these quantities, analog in nature, can be measured accurately and precisely by inherently digital embedded controllers.
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| 25. |
- Bengtsson, Lars, 1963
(författare)
-
New design ideas for TDR-based liquid level detectors
- 2017
-
Ingår i: I2MTC 2017 - 2017 IEEE International Instrumentation and Measurement Technology Conference. 22-25 May 2017. Turin, Italy. Proceedings. - : IEEE. - 1091-5281. - 9781509035960
-
Konferensbidrag (refereegranskat)abstract
- This work suggests some new solutions to TDR-based liquid level detectors. A 3D-printed waveguide cylinder has been designed in order to increase the sensitivity of the level measurement. By wrapping the probing waveguide-pair around a cylinder, an inclination angle ϕ is introduced which increases the time-of-flight by a factor of 1/sinϕ and hence the level resolution is increased (by the same factor). This work also illustrates how nanosecond pulses (for TDR systems) can be generated by applying a technique usually found in FIMs (Field Ion Microscopes). A time resolution of 2 ns/mm (of liquid level) is reported and a generic nanosecond pulse generator isdemonstrated.
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| 26. |
- Birk, Wolfgang, et al.
(författare)
-
iRoad - cooperative road infrastructure systems for driver support
- 2009
-
Ingår i: 16th World Congress and Exhibition on Intelligent Transport Systems 2009. - Red Hook : Curran Associates, Inc.. - 9781617385896
-
Konferensbidrag (refereegranskat)abstract
- This paper discusses the design and implementation of a cooperative road infrastructure systems, which uses an intelligent road surface. Using an overtaking assist feature as an example it is shown how such a feature can be designed and implemented on a road infrastructure and integrated with drivers and passengers using IMS. The feasibility of this feature is assessed from a functional and communication perspective. Moreover, first results from real-life tests on the Swedish highway E4 are presented which motivate the next research and development steps.
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| 27. |
- Riliskis, Laurynas, et al.
(författare)
-
Enabling remote controlled road surface networks for enhanced ITS
- 2011
-
Konferensbidrag (refereegranskat)abstract
- Intelligent Transportation Systems (ITS) will, in the future, play a key role to improve transportation efficiency and safety. However, cost-benefit of deploying traditional ITS is retarded by expensive equipment, infrastructure, installation and maintenance. The demo presents a replica of a real world experimental ITS application using recently proposed Road Surface Network architecture. The demonstrated "intelligent roundabout'' application is intended to warn and inform drivers about an upcoming roundabout and to prevent driving straight into collision. We show a lab prototype system consisting of: an authentic sensor node platform enabled for car detection, secure multihop communications and the running light application, a base station with system control center.
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| 28. |
- Lv, Zhihan, Dr. 1984-, et al.
(författare)
-
Editorial : 5G for Augmented Reality
- 2022
-
Ingår i: Mobile Networks and Applications. - : Springer. - 1383-469X .- 1572-8153.
-
Tidskriftsartikel (refereegranskat)
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| 29. |
- Farooqui, Ashfaq, et al.
(författare)
-
On Active Learning for Supervisor Synthesis
- 2024
-
Ingår i: IEEE Transactions on Automation Science and Engineering. - : Institute of Electrical and Electronics Engineers Inc.. - 1545-5955 .- 1558-3783. ; 21, s. 78-
-
Tidskriftsartikel (refereegranskat)abstract
- Supervisory control theory provides an approach to synthesize supervisors for cyber-physical systems using a model of the uncontrolled plant and its specifications. These supervisors can help guarantee the correctness of the closed-loop controlled system. However, access to plant models is a bottleneck for many industries, as manually developing these models is an error-prone and time-consuming process. An approach to obtaining a supervisor in the absence of plant models would help industrial adoption of supervisory control techniques. This paper presents, an algorithm to learn a controllable supervisor in the absence of plant models. It does so by actively interacting with a simulation of the plant by means of queries. If the obtained supervisor is blocking, existing synthesis techniques are employed to prune the blocking supervisor and obtain the controllable and non-blocking supervisor. Additionally, this paper presents an approach to interface the with a PLC to learn supervisors in a virtual commissioning setting. This approach is demonstrated by learning a supervisor of the well-known example simulated in Xcelgo Experior and controlled using a PLC. interacts with the PLC and learns a controllable supervisor for the simulated system. Note to Practitioners—Ensuring the correctness of automated systems is crucial. Supervisory control theory proposes techniques to help build control solutions that have certain correctness guarantees. These techniques rely on a model of the system. However, such models are typically unavailable and hard to create. Active learning is a promising technique to learn models by interacting with the system to be learned. This paper aims to integrate active learning and supervisory control such that the manual step of creating models is no longer needed, thus, allowing the use of supervisory control techniques in the absence of models. The proposed approach is implemented in a tool and demonstrated using a case study.
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| 30. |
- Bencheikh Lehocine, Chouaib, 1993, et al.
(författare)
-
Robust Analog Beamforming for Periodic Broadcast V2V Communication
- 2022
-
Ingår i: IEEE Transactions on Intelligent Transportation Systems. - 1524-9050 .- 1558-0016. ; 23:10, s. 18404-18422
-
Tidskriftsartikel (refereegranskat)abstract
- We generalize an existing low-cost analog signal processing concept that takes advantage of the periodicity of vehicle-to-vehicle broadcast service to the transmitter side. In particular, we propose to process multiple antennas using either an analog beamforming network (ABN) of phase shifters, or an antenna switching network (ASN) that periodically alternates between the available antennas, to transmit periodic messages to receivers that have an analog combining network (ACN) of phase shifters, which has been proposed in earlier work. To guarantee robustness, we aim to minimize the burst error probability for the worst receiving vehicular user, in a scenario of bad propagation condition that is modeled by a single dominant path between the communicating vehicles. In absence of any form of channel knowledge, we analytically derive the optimal parameters of both ABN and ASN. The ABN beamforming vector is found to be optimal for all users and not only for the worst receiving user. Further, we demonstrate that Alamouti scheme for the special case of two transmit antennas yields similar performance to ABN and ASN. At last, we show that the derived parameters of the two proposed transmission strategies are also optimal when hybrid ACN-maximal ratio combining is used at the receiver.
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| 31. |
- Huang, Lirong, et al.
(författare)
-
Stability of Singular Stochastic Systems With Markovian Switching
- 2011
-
Ingår i: IEEE Transactions on Automatic Control. - 0018-9286 .- 1558-2523. ; 56:2, s. 424-429
-
Tidskriftsartikel (refereegranskat)abstract
- In recent years, singular hybrid systems have received considerable attention. However, few results are concerned with stability of singular hybrid stochastic systems. Based on a stability result for singular hybrid systems, this note studies mean-square stability of singular hybrid stochastic systems. It is found that the diffusions and the Markov chain may play important roles in system analysis in mean-square sense. As a special case, a criterion for mean-square stability of hybrid stochastic systems is developed by the frequency domain approach.
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| 32. |
- Jacobsson, Sven, 1990, et al.
(författare)
-
Massive MU-MIMO-OFDM Uplink with Hardware Impairments: Modeling and Analysis
- 2018
-
Ingår i: Conference Record - Asilomar Conference on Signals, Systems and Computers. - 1058-6393. ; , s. 1829-1835
-
Konferensbidrag (refereegranskat)abstract
- © 2018 IEEE. We study the impact of hardware impairments at the base station (BS) of an orthogonal frequency-division multiplexing (OFDM)-based massive multiuser (MU) multiple-input multiple-output (MIMO) uplink system. We leverage Bussgang's theorem to develop accurate models for the distortions caused by nonlinear low-noise amplifiers, local oscillators with phase noise, and oversampling finite-resolution analog-to-digital converters. By combining the individual effects of these hardware models, we obtain a composite model for the BS-side distortion caused by nonideal hardware that takes into account its inherent correlation in time, frequency, and across antennas. We use this composite model to analyze the impact of BS-side hardware impairments on the performance of realistic massive MU-MIMO-OFDM uplink systems.
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| 33. |
- Jönsson, Ulf T.
(författare)
-
Primal and Dual Criteria for Robust Stability and Their Application to Systems Interconnected Over a Bipartite Graph
- 2010
-
Ingår i: 2010 AMERICAN CONTROL CONFERENCE. - : IEEE. - 9781424474271 ; , s. 5458-5464
-
Konferensbidrag (refereegranskat)abstract
- A dual formulation of a standard stability criterion from robust control is derived and investigated. The dual provides additional insight into the stability criterion and is sometimes easier to use than the primal. This is illustrated for a class of systems interconnected over a bipartite graph. The dual criterion reveals structural properties of the interconnection which in some cases are easy to investigate using low complexity tests.
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| 34. |
- Stankovic, Milos S., et al.
(författare)
-
Decentralized Consensus Based Control Methodology for Vehicle Formations in Air and Deep Space
- 2010
-
Ingår i: 2010 AMERICAN CONTROL CONFERENCE. - : IEEE. - 9781424474271 ; , s. 3660-3665
-
Konferensbidrag (refereegranskat)abstract
- In this paper a new methodology is proposed for decentralized overlapping tracking control of autonomous vehicles in air and deep-space. The methodology is based on the application of recently proposed decentralized consensus-based state estimators [1], [2], [3], in conjunction with the globally LQ optimal state feedback control law. In the case of unmanned aerial vehicles (UAVs), a specific formation model is proposed and the globally optimal control law derived using an aggregation of the formation model. It is demonstrated experimentally that the whole control scheme is advantageous over similar decentralized control algorithms. In the case of deep-space formations, it is shown that a decentralized consensus based estimator can be constructed using specific nonsingular transformations from one realization of the observable part of the formation model to another. Experimental results demonstrate excellent properties of a control scheme based on this estimator in the case of a small number of available measurements.
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| 35. |
|
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| 36. |
- Teixeira, Andre, et al.
(författare)
-
Networked Control Systems under Cyber Attacks with Applications to Power Networks
- 2010
-
Ingår i: 2010 AMERICAN CONTROL CONFERENCE. - : IEEE. - 9781424474271 ; , s. 3690-3696
-
Konferensbidrag (refereegranskat)abstract
- Networked control systems under certain cyber attacks are analyzed. The communication network of these control systems make them vulnerable to attacks from malicious outsiders. Our work deals with two types of attacks: attacks on the network nodes and attacks on the communication between the nodes. We propose a distributed scheme to detect and isolate the attacks using observers. Furthermore, we discuss how to reduce the number of observer nodes while maintaining the coverage of the entire network. The results are applied to two classes of networked control systems: a network running the consensus protocol and a power network defined by the linearized swing equation. Sufficient conditions for the existence of the proposed attack detection scheme are provided for the first class of systems. For the second class, we provide a necessary condition for the existence of the proposed detection scheme.
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| 37. |
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| 38. |
- Seoane Martinez, Fernando, 1976
(författare)
-
Electrical Bioimpedance Cerebral Monitoring: Fundamental Steps towards Clinical Application
- 2007
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Neurologically related injuries cause a similar number of deaths as cancer, and brain damage is the second commonest cause of death in the world and probably the leading cause of permanent disability. The devastating effects of most cases of brain damage could be avoided if it were detected and medical treatment initiated in time. The passive electrical properties of biological tissue have been investigated for almost a century and electrical bioimpedance studies in neurology have been performed for more than 50 years. Even considering the extensive efforts dedicated to investigating potential applications of electrical bioimpedance for brain monitoring, especially in the last 20 years, and the specifically acute need for such non-invasive and efficient diagnosis support tools, Electrical Bioimpedance technology has not made the expected breakthrough into clinical application yet. In order to reach this stage in the age of evidence-based medicine, the first essential step is to demonstrate the biophysical basis of the method under study. The present research work confirms that the cell swelling accompanying the hypoxic/ischemic injury mechanism modifies the electrical properties of brain tissue, and shows that by measuring the complex electrical bioimpedance it is possible to detect the changes resulting from brain damage. For the development of a successful monitoring method, after the vital biophysical validation it is critical to have available the proper electrical bioimpedance technology and to implement an efficient protocol of use. Electronic instrumentation is needed for broadband spectroscopy measurements of complex electrical bioimpedance; the selection of the electrode setup is crucial to obtain clinically relevant measurements, and the proper biosignal analysis and processing is the core of the diagnosis support system. This work has focused on all these aspects since they are fundamental for providing the solid medico-technological background necessary to enable the clinical usage of Electrical Bioimpedance for cerebral monitoring.
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| 39. |
- Fan, Yuchuan, et al.
(författare)
-
Feedforward Neural Network-Based EVM Estimation : Impairment Tolerance in Coherent Optical Systems
- 2022
-
Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - : Institute of Electrical and Electronics Engineers Inc.. - 1077-260X .- 1558-4542. ; 28:4
-
Tidskriftsartikel (refereegranskat)abstract
- Error vector magnitude (EVM) is commonly used for evaluating the quality of m-ary quadrature amplitude modulation (mQAM) signals. Recently proposed deep learning techniques for EVM estimation extend the functionality of conventional optical performance monitoring (OPM). In this article, we evaluate the tolerance of our developed EVM estimation scheme against various impairments in coherent optical systems. In particular, we analyze the signal quality monitoring capabilities in the presence of residual in-phase/quadrature (IQ) imbalance, fiber nonlinearity, and laser phase noise. We use feedforward neural networks (FFNNs) to extract the EVM information from amplitude histograms of 100 symbols per IQ cluster signal sequence captured before carrier phase recovery. We perform simulations of the considered impairments, along with an experimental investigation of the impact of laser phase noise. To investigate the tolerance of the EVM estimation scheme to each impairment type, we compare the accuracy for three training methods: 1) training without impairment, 2) training one model for all impairments, and 3) training an independent model for each impairment. Results indicate a good generalization of the proposed EVM estimation scheme, thus providing a valuable reference for developing next-generation intelligent OPM systems.
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| 40. |
- Fritzin, Jonas, et al.
(författare)
-
Phase Predistortion of a Class-D Outphasing RF Amplifier in 90 nm CMOS
- 2011
-
Ingår i: IEEE Transactions on Circuits and Systems - II - Express Briefs. - 1549-7747 .- 1558-3791. ; 58:10, s. 642-646
-
Tidskriftsartikel (refereegranskat)abstract
- This brief presents a behavioral model structure and a model-based phase-only predistortion method that are suitable for outphasing RF amplifiers. The predistortion method is based on a model of the amplifier with a constant gain factor and phase rotation for each outphasing signal, and a predistorter with phase rotation only. The method has been used for enhanced data rates for GSM evolution (EDGE) and wideband code-division multiple-access (WCDMA) signals applied to a Class-D outphasing RF amplifier with an on-chip transformer used for power combining in 90-nm CMOS. The measured peak power at 2 GHz was +10.3 dBm with a drain efficiency and power-added efficiency of 39% and 33%, respectively. For an EDGE 8 phase-shift-keying (8-PSK) signal with a phase error of 3 degrees between the two input outphasing signals, the measured power at 400 kHz offset was -65.9 dB with predistortion, compared with -53.5 dB without predistortion. For a WCDMA signal with the same phase error between the input signals, the measured adjacent channel leakage ratio at 5-MHz offset was -50.2 dBc with predistortion, compared with -38.0 dBc without predistortion.
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| 41. |
- Savic, Vladimir, et al.
(författare)
-
Belief consensus algorithms for fast distributed target tracking in wireless sensor networks
- 2014
-
Ingår i: Signal Processing. - : Elsevier. - 0165-1684 .- 1872-7557. ; 95, s. 149-160
-
Tidskriftsartikel (refereegranskat)abstract
- In distributed target tracking for wireless sensor networks, agreement on the target state can be achieved by the construction and maintenance of a communication path, in order to exchange information regarding local likelihood functions. Such an approach lacks robustness to failures and is not easily applicable to ad-hoc networks. To address this, several methods have been proposed that allow agreement on the global likelihood through fully distributed belief consensus (BC) algorithms, operating on local likelihoods in distributed particle filtering (DPF). However, a unified comparison of the convergence speed and communication cost has not been performed. In this paper, we provide such a comparison and propose a novel BC algorithm based on belief propagation (BP). According to our study, DPF based on metropolis belief consensus (MBC) is the fastest in loopy graphs, while DPF based on BP consensus is the fastest in tree graphs. Moreover, we found that BC-based DPF methods have lower communication overhead than data flooding when the network is sufficiently sparse.
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| 42. |
- Xie, Haotian, et al.
(författare)
-
Robust parallel predictive torque control with model reference adaptive estimator for im drives
- 2020
-
Ingår i: Proceedings - 2020 International Conference on Electrical Machines, ICEM 2020. ; 23 August 2020, s. 1219-1224
-
Konferensbidrag (refereegranskat)abstract
- This paper presents the robustness improvement for the proposed parallel structure predictive torque control (PPTC) via a MRA-based estimator. Although predictive torque control (PTC) has the merits of lower switching frequency and straightforward implementation, it inevitably suffers from the inherent drawbacks of high torque ripple and inappropriate tuning of the weighting parameter. To solve this issue, the proposed PPTC employs two homogeneous objective terms which are optimized in a parallel strucutre, to bypass the usage of weighting parameters. However, the parameter mismatches in the control plant will lead to the prediction torque and flux error, which further impacts the control behavior of the system. Therefore, this paper evaluates the parameter sensitivity for PPTC, aiming to improve robustness of the proposed algorithm with a MRA-based parameter estimator. Finally, the validity of the proposed scheme is confirmed through an experimental assessment.
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| 43. |
- Yin, Hang, et al.
(författare)
-
Policy Learning with Embedded Koopman Optimal Control
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Embedding an optimization process has been explored for imposing efficient and flexible policy structures. Existing work often build upon nonlinear optimization with explicitly unrolling of iteration steps, making policy inference prohibitively expensive for online learning and real-time control. Our approach embeds a linear-quadratic-regulator (LQR) formulation with a Koopman representation, thus exhibiting the tractability from a closed-form solution and richness from a non-convex neural network. We use a few auxiliary objectives and reparameterization to enforce optimality conditions of the policy that can be easily integrated to standard gradient-based learning. Our approach is shown to be effective for learning policies rendering an optimality structure and efficient reinforcement learning, including simulated pendulum control, 2D and 3D walking, and manipulation for both rigid and deformable objects. We also demonstrate real world application in a robot pivoting task.
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| 44. |
- Bengtsson, Lars, 1963
(författare)
-
RISC-baserad 50 MHz räknare med alfanumerisk display
- 1995
-
Ingår i: Allt om elektronik. ; 6, s. 35-37
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Denna artikel presenterar en konstruktion som använder en RISC-kontroller (PIC16C54) som frekvensräknare. Frekvensen räknas på controllerns RTCC-ingång och signalfrekvensen, uttryckt i kHz visas på en alfanumerisk display.
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| 45. |
- Bengtsson, Lars, 1963
(författare)
-
Single-chip Implementation of LVDT Signal Conditioning
- 2018
-
Ingår i: American Journal of Sensor Technology. - 2373-3454 .- 2373-3462. ; 5:1, s. 7-16
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this work was to prove that the signal conditioning electronics for linear variable transformers (LVDTs) can be implemented in inexpensive, general-purpose 8-bit microcontrollers, making expensive dedicated signal conditioning chips redundant. A low-cost, high-resolution signal conditioning solution for LVDTs is presented. Apart from a few external passive components, the entire solution is implemented in a low-cost, analog-digital hybrid microcontroller. The excitation sinusoid is generated by filtering out the fundamental frequency of a (self-sustained) pwm-generated square wave and the secondary coils’ signals are demodulated with classic peak detector circuits implemented in the microcontroller using a combination of its embedded analog and digital building blocks. A resolution of 1 μm over a range of ±6.35 mm for a commercial LVDT is reported and an uncertainty of 6 μm in the absolute value is deduced. The entire solution is implemented as surface mounted components on a small printed circuit board and the LVDT core displacement is displayed on an LCD display. Due to the simplicity and low-cost components required, this signal conditioning proposal has the potential to have a significant impact on commercial LVDT signal conditioning chips in the future since it is significantly less expensive than the present state-of-the-art signal conditioning chips offered by the main commercial suppliers and other solutions previously suggested in scientific literature.
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| 46. |
- Selvaraj, Yuvaraj, 1990
(författare)
-
On Provably Correct Decision-Making for Automated Driving
- 2020
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The introduction of driving automation in road vehicles can potentially reduce road traffic crashes and significantly improve road safety. Automation in road vehicles also brings several other benefits such as the possibility to provide independent mobility for people who cannot and/or should not drive. Many different hardware and software components (e.g. sensing, decision-making, actuation, and control) interact to solve the autonomous driving task. Correctness of such automated driving systems is crucial as incorrect behaviour may have catastrophic consequences. Autonomous vehicles operate in complex and dynamic environments, which requires decision-making and planning at different levels. The aim of such decision-making components in these systems is to make safe decisions at all times. The challenge of safety verification of these systems is crucial for the commercial deployment of full autonomy in vehicles. Testing for safety is expensive, impractical, and can never guarantee the absence of errors. In contrast, formal methods , which are techniques that use rigorous mathematical models to build hardware and software systems can provide a mathematical proof of the correctness of the system. The focus of this thesis is to address some of the challenges in the safety verification of decision-making in automated driving systems. A central question here is how to establish formal verification as an efficient tool for automated driving software development. A key finding is the need for an integrated formal approach to prove correctness and to provide a complete safety argument. This thesis provides insights into how three different formal verification approaches, namely supervisory control theory, model checking, and deductive verification differ in their application to automated driving and identifies the challenges associated with each method. It identifies the need for the introduction of more rigour in the requirement refinement process and presents one possible solution by using a formal model-based safety analysis approach. To address challenges in the manual modelling process, a possible solution by automatically learning formal models directly from code is proposed.
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| 47. |
- Törngren, Martin, 1963-, et al.
(författare)
-
Strategies and considerations in shaping cyber-physical systems education
- 2016
-
Ingår i: ACM SIGBED Review. - : Association for Computing Machinery (ACM). - 1551-3688. ; :1, s. 53-60
-
Tidskriftsartikel (refereegranskat)abstract
- Embedded and Cyber-Physical Systems education faces several challenges as well as opportunities as every-“thing” becomes connected, and as technology development accelerates. Initiatives such as CDIO, as well as several other academic and industry initiatives to create new CPS programs illustrate strong interests and awareness of these challenges. We provide an overview of foreseen educational needs, existing state of the art in education and an analysis of the subject of CPS with the purpose of understanding the implications for education. The investigation points to key issues in curriculum design regarding balancing depth and breadth, theory and practices, academic and industrial needs, and core technical skills with complementary skills. Curricula in CPS could, if the right balance is achieved, educate CPS engineers of the future that are “ready to engineer”. We conclude by synthesizing high level guidelines in terms of strategies and considerations for CPS curriculum development.
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| 48. |
- Dadhich, Siddharth, et al.
(författare)
-
Machine Learning approach to Automatic Bucket Loading
- 2016
-
Ingår i: 24th Mediterranean Conference on Control and Automation (MED). - Piscataway, NJ : IEEE Communications Society. - 9781467383455 ; , s. 1260-1265
-
Konferensbidrag (refereegranskat)abstract
- The automation of bucket loading for repetitive tasks of earth-moving operations is desired in several applications at mining sites, quarries and construction sites where larger amounts of gravel and fragmented rock are to be moved. In load and carry cycles the average bucket weight is the dominating performance parameter, while fuel efficiency and loading time also come into play with short loading cycles. This paper presents the analysis of data recorded during loading of different types of gravel piles with a Volvo L110G wheel loader. Regression models of lift and tilt actions are fitted to the behavior of an expert driver for a gravel pile. We present linear regression models for lift and tilt action that explain most of the variance in the recorded data and outline a learning approach for solving the automatic bucket loading problem. A general solution should provide good performance in terms of average bucket weight, cycle time of loading and fuel efficiency for different types of material and pile geometries. We propose that a reinforcement learning approach can be used to further refine models fitted to the behavior of expert drivers, and we briefly discuss the scooping problem in terms of a Markov decision process and possible value functions and policy iteration schemes.
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| 49. |
- Fu, Keren, 1988, et al.
(författare)
-
One-Class SVM Assisted Accurate Tracking
- 2012
-
Ingår i: 6th ACM/IEEE Int'l Conf on Distributed Smart Cameras (ICDSC 12), Oct 30 - Nov.2, 2012, Hong Kong. ; , s. 6 pages-
-
Konferensbidrag (refereegranskat)abstract
- Recently, tracking is regarded as a binary classification problem by discriminative tracking methods. However, such binary classification may not fully handle the outliers, which may cause drifting. In this paper, we argue that tracking may be regarded as one-class problem, which avoids gathering limited negative samples for background description. Inspired by the fact the positive feature space generated by One-Class SVM is bounded by a closed sphere, we propose a novel tracking method utilizing One-Class SVMs that adopt HOG and 2 bit-BP as features, called One-Class SVM Tracker (OCST). Simultaneously an efficient initialization and online updating scheme is alsoproposed. Extensive experimental results prove that OCST outperforms some state-of-the-art discriminative tracking methods on providing accurate tracking and alleviating serious drifting.
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| 50. |
- Theorin, Alfred, et al.
(författare)
-
An Event-Driven Manufacturing Information System Architecture
- 2015
-
Ingår i: 15th IFAC Symposium onInformation Control Problems inManufacturing - INCOM 2015. - : Elsevier BV. ; 48:3, s. 547-554
-
Konferensbidrag (refereegranskat)abstract
- Future manufacturing systems need to be more flexible, to embrace tougher and constantly changing market demands. They also need to make better use of plant data, ideally utilizing all data from the entire plant. Low-level data should be refined to real-time information for decision making, to facilitate competitiveness through informed and timely decisions. The Line Information System Architecture, LISA, is designed to enable flexible factory integration and data utilization. In LISA, international standards and established off-the-shelf technologies have been combined with the main objective to be industrially applicable. LISA is an event-driven architecture with a prototype-oriented information model and formalized transformation services. It features loose coupling, flexibility, and ease of retrofitting legacy devices. The architecture has been evaluated on both real industrial data and industrial demonstrators and is also being installed at a large automotive company.
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