doc. Ing. Jiří Novák, Ph.D.

The article informs community and companies about CAN bus related projects and results achieved and offered by the Czech Technical University, Faculty of Electrical Engineering. The article informs regarding CAN FD controller open-source IP core developed at Czech Technical University and current integration and release of the corresponding driver in mainline Linux operating system kernel. Emulation of the CTU CAN FD IP core is available in mainline QEMU emulator as the result of previous work. The use of own CAN controller boards and ecosystem for testers delivered to Skoda Auto and prototype of precise CAN (FD) latencies evaluation are described as well.

Výzkumná skupina zaměřená na problematiku automobilové elektroniky a vozidlových komunikací se zformovala na katedře měření ČVUT FEL na přelomu století pod vedením doc. Petra Kocourka. Celá její existence je spojena s úzkou a dlouhodobou spoluprací s několika odděleními vývoje Škody Auto, takže lze říci, že veškeré výsledky výzkumu a vývoje jsou vzápětí aplikovány v praxi. Spolupráce se zaměřuje zejména na problematiku automatizovaného testování, která v současné době nabývá na významu vzhledem ke stále se rozšiřujícímu portfoliu uživatelských funkcí vozidel, jízdních asistentů, informačních a komunikačních systémů apod. Během uplynulých více než 20 let bylo navrženo a realizováno několik generací automatizovaných testerů chování řídicích jednotek vozidel na vozidlových sítích CAN a LIN; v rámci jejich vývoje byly vyvinuty a následně publikovány unikátní měřicí metody.

This paper deals with problematics of structure of Timed Automata models suitable for Model-Based Testing of automotive systems. Previous ex-periments, primarily focused on the environmental models, have shown that their structure does not significantly affect the coverage speed of testing process. How-ever, similar questions regarding the observer part of the system model remained open. This paper analyzes those remaining questions and focuses on uncovering possible relation between an observer model structure and the quality of gener-ated test sequences according to multiple criteria. Goal of presented experiments is to compare multiple modeling approaches and discover which one is most suit-able for automotive systems.

This paper aims to present a software facility designed to accompany the currently developed automotive radar target simulation platform. This simulation platform, together with the software facility presented in this paper, is envisioned to confront recent challenges introduced by rising complexity of radar-based automotive systems. The presented software facility allows to easily control the companion target simulation platform and design traffic scenarios for the radar testing. The trajectory design used by the app is implementation-agnostic and is based on the interpolation of linear trajectory segments with selectable velocity profiles. That enables future integration of the platform into the testing process and virtual reality-based testing platform.

Radar sensors are becoming standard equipment in modern cars. They are an integral part of systems for blind-spot detection, adaptive cruise control, or emergency braking. All these systems have to be thoroughly tested to achieve a high-quality standard of produced vehicles. One of the commonly adopted techniques is Hardware-in-the-Loop testing. A Radar sensor-based systems Hardware-in-the-Loop testing requires the capability of simulation a target to the sensor. The paper presents a purely digital approach to simulation of static as well as moving target (E.g., car) to an automotive radar sensor. The absence of analog or mechanical parts significantly reduces the solution costs.

Adaptive Random Prioritization is a Test Case Prioritization technique which orders test cases within a test suite with a goal of earlier fault detection using a semi-random heuristics. Compared to other Test Case Prioritization methods, Adaptive Random Prioritization has only an average fault detection performance. However, it is less sensitive to some test suite features which negatively affect fault detection performance than other TCP techniques due to its semi-random nature. The article proposes an improved version of Adaptive Random Prioritization technique. The key idea behind the presented enhancement is to extend the test case selection process with additional information about control flow and change of test statements coverage of a test suite. The enhancement replaces the original Test set distance function with a Multi-Criteria Decision-Making method. Validity of the proposed method is evaluated on data from six embedded systems. The evaluation criterion is fault detection performance expressed by Average Percentage of Faults Detection metric and Â12 statistic. The proposed improvement achieved better fault detection performance for all examined systems.

Test case prioritization (TCP) refers to the process, which evaluates test cases ranking within a test suite. Currently, the focus of TCP research lay mainly in code-based testing; however, the Model-Based Testing (MBT) context, still need more investigation. This paper presents a new distance function for defining the degree of similarity between MBT generated test cases. These test cases are represented by labeled graphs, and their similarity is measured. In the paper, the function is applied in Hint-Based Adaptive Random Prioritization method, and improved fault-detection performance is presented.

Deployment of the Model-based Testing methods in practice has not achieved the level it deserves. To help dissemination, as well as to improve the testing process in a particular domain, this paper presents a new Test Generation tool on a case study. The domain is automotive integration testing. The new tool is named Taster and utilizes Timed Automata for the online Model-based test generation. The objective of these tests is testing of integration of automotive comfort systems. The proposed concept, the system modeling, and the new software tool is evaluated on testing of a Keyless Access System. Purpose of the paper is to present an approach for automatic test generation intended for automotive integration testing.

Network operation of FlexRay Electronic Control Unit (ECU) in passenger cars is influenced by the significant number of parameters that have to be written into the ECU FlexRay controller. To keep the FlexRay network robust, the correct parameter values must be set in all ECUs of the FlexRay communication cluster. This is not a trivial task since particular ECUs are supplied by different manufacturers and any manufacturer can change some parameter either by mistake or even intentionally. The effect of such a change is generally unpredictable and can often be observed under specific operational conditions only. The most serious effect is a global FlexRay network failure, which usually leads to the fatal vehicle malfunction. Hence it was necessary to develop, implement and validate new dedicated measurement methods, enabling the evaluation of actual values of the most critical FlexRay parameters at the Open Systems Interconnection (OSI) data-link layer and thus the ECUs individual acceptances testing for system integrator verification purposes. As the mass production of FlexRay controllers is not applicable due to a lack of test specific features, deployment of these methods is enabled by utilization of unique FPGA-based FlexRay controller implementation. Proposed measurement methods are focused on parameters specifying the FlexRay wakeup protocol, FlexRay startup procedure, and the FlexRay synchronization mechanism. Each measurement method is described in detail, including its limits and prerequisites. All the developed methods were validated by experiments on real FlexRay networks and results are included in the paper. Two different types of FlexRay controller core (Freescale and Bosch E-Ray) were used in ECU under test (EUT) to eliminate the risk of measurement method dependence on a specific controller implementation.

The paper presents an optimized framework for model-based testing of automotive distributed system and a method of automatic assignment of testing priorities used within the framework. The proposed method, envisioned for integration into existing, currently developed model-based testing tool, utilizes classifiers in order to assign testing priorities automatically to specific parts of the tested system. The paper also introduces a set of supplemental data enriching the modeling language that are exploited by the proposed method during the classification process. It is shown, that advantages of the presented approach, such as low requirements for the testing operators’ insight, are valuable for the automotive distributed systems testing process.

The paper presents a framework for model-based testing of automotive distributed system and a method of automatic assignment of testing priorities used within the framework. The proposed method utilizes classifiers for automatic assignment of testing priorities to specific parts of the tested system. The paper also introduces a set of extraneous data accompanying the modeling language that are exploited by the proposed method during the classification process. It is shown, that advantages of the presented approach, such as lower requirements for the testing operators’ knowledge, are valuable for the automotive distributed systems testing process.

Model oriented testing methods are known relatively long time, but the right time for viable deployment is coming up now with the continuously growing amount of vehicle electronic systems. Paper proposes a new Model-Based Testing approach to testing of automotive electronics systems. The key concept is the utilization of Timed Automata for online testing of automotive electronic control units. System modeling, the new tool, a bit of necessary technology and preliminary results intended to identify future research goal are presented.

The paper presents an optimized framework for model-based testing of automotive distributed system and a method of automatic assignment of testing priorities used within the framework. The proposed method, envisioned for integration into existing, currently developed model-based testing tool, utilizes classifiers in order to assign testing priorities automatically to specific parts of the tested system. The paper also introduces a set of supplemental data enriching the modeling language that are exploited by the proposed method during the classification process. It is shown, that the presented approach’s advantages, such as low requirements for the testing operators’ insight, are valuable for the automotive distributed systems testing process.

Current trends in the passenger car industry are focused on reduction of manufacturing costs and thus increasing competitiveness on the automotive market. This paper introduces a new approach to vehicle diagnostics, promising direct cost reduction of in-vehicle diagnostic subsystems. The new approach provides for an easy transition from currently used concept of decentralized diagnostic probes to a centralized concept, based on (in an ideal case) a single diagnostic probe. This concept is demonstrated in a case study, which is focused on vehicle ignition system diagnostics. Diagnostic signatures are measured in vehicle supply network, and classified using additional information acquired from internal vehicle communication network. Case study results are presented including the discussion of advantages and limits of the centralized diagnostics concept.

This paper presents newly researched and developed network layer protocol for narrowband power line communication (PLC) within the last mile of advanced metering management systems. This communication medium is known for its low data rates and issues with signal propagation and noise inherence. After the network properties are introduced and some of the published PLC routing papers are discussed, our network layer protocol concept is described with emphasis on the routing algorithm and route optimizations. The protocol is designed to optimize the energy efficiency of the PLC network. The next part of the paper briefly describes the network simulator and its model, which was used during the protocol development and debugging. Several networks with constant and dynamic channel parameters were simulated. The results are presented at the end of the paper. Final results proving energy efficiency and its positive influence on the network performance are presented in comparison to the minimum hop count metric.

Controller area network (CAN) is deployed in wide scale of applications at present. Many of these applications are sensitive to faults in terms of quality of communication. The article describes a novel online diagnostic method which aim is to recognize progressively degrading nodes on the data bus. The method uses existing network equipment and requires no additional/specialized network nodes. Standard components for CAN bus faults management like node error counters are used instead.

Cont rol ler area network (CAN) is now used in wide range of distributed applications. The quality of communication in such applications is usually an important factor. This paper describes validation of new developed online diagnostic method which aim is to recognize progressively degrading nodes on the CAN bus. The method uses existing network equipment and requires no additional / specialized network nodes. Standard component s for CAN bus faults management like node error counters are used instead. Validation of diagnostic model compares results of the simulations with the results achieved on actual CAN bus implementation with progressively degrading node.

Goal of this paper is to propose an improvement of an automotive distributed system testing process, namely the part called integration testing. The improvement is focused on test cases development, which is today done mostly manually by test engineers. The work is focused on deployment of Model-Based Testing method on field of integration testing.

Current trends in passenger car industry are focused on ceaseless reduction of production costs and thus on more competitive production on an automotive market. This paper describes a new diagnostics method promising direct costs reduction of in-vehicle diagnostics subsystems. The method provides for an easy transition from current decentralized concept of diagnostic obes for particular elements of electric and electronic equipment to a centralized concept based on (in an ideal case) a single measuring probe. Case study on the vehicle ignition system is presented, demonstrating the method principle, advantages and limits. Diagnostic method is based on localization and identification of fault signatures in vehicle power supply network using a template matching algorithm.

FlexRay is an incoming communication standard for automotive applications. Paper deals with an implementation of unique FlexRay communication controller in FPGA and shows examples of its usage for FlexRay Wakeup and Startup configuration parameters evaluation.

FlexRay is an incoming standard of automotive distributed system intended for safety critical applications like x-by-wire. The first part of the chapter provides an introduction to the FlexRay standard, presents an analytic model of FlexRay Synchronization Mechanism, validation of this model and offers its usage for measurement of parameters of synchronization mechanism in real FlexRay networks. The second part of the chapter presents a case study of FlexRay application in a distributed implementation of ABS (Anti-lock Braking System) in vehicle. The anti-lock braking system is nowadays a part of almost every vehicle. In order to work properly, the anti-lock braking system needs to have actual information about the rotation of every wheel. Currently, the information about the frequency of wheel rotation is being transmitted via the current loop. This paper describes a method, where the information from the rotation sensors of the wheels is transmitted into the control unit through the FlexRay bus. Additional wireless acceleration sensors located on the wheels are used to improve the ABS performance.

For FlexRay fault free communication it is necessary to ensure correct parameterization of each network node. This paper describes methods for evaluation of basic internal timing parameters of a single FlexRay node. Methods reflect common situation in automotive industry, where each electronic control unit comes from different manufacturer. No direct access to ECUs actual parameters is usually available, thus the independent methods to validate specific parameters are needed.

FlexRay is an incoming standard for automotive distributed systems. For safety critical applications like x-by-wire systems it is necessary to develop techniques for their verification and validation. This paper presents a model of FlexRay Synchronization Mechanism, validation of this model and offers its usage for validation of parameters of synchronization mechanism in real FlexRay networks.

The current trends in vehicle diagnostics tend to decrease production costs, whereas the same or even higher user safety and comfort level has to be assured. One option is using the centralized diagnostics, which doesn´t increase the production costs and still gives precision to the detection of an actual fault. The centralized diagnostics is an alternative to the today online diagnostic solutions. It is based on diagnostic models of every single part of the vehicle in which a properly as well as a faulty behaviour can be simulated. In this paper, the electromechanical valve of anti-lock braking system is described and modelled in detail. In order to proceed with the centralized diagnose of the anti-lock braking system of the vehicle, good understanding of the anti-lock braking system valve is necessary. A physical analysis, mathematical description and a general model of the valve was carried out.

This paper presents new routing protocol designed for use in AMR and AMM systems using power-line communication (PLC) for data collecting and network control at their last mile. First part of the paper describes the AMR and AMM systems and the reasons for their implementation. Further the narrowband power-line communication as relatively simple way for data transfers at the last mile is shown and briefly described. Power-line channel characteristic implies a need of a network layer protocol implemented in the PLC nodes for such large-scaled narrowband PLC networks. In the next part simple routing protocol algorithm based on minimal energy consumption is presented. Finally the paper describes simulation software used for protocol design and its functional validation. Power line channel model used in simulator is described in detail.

An increasing number of Electronic Control Units in passenger cars and high communication traffic have led the car manufacturers to splitting a single CAN network into several dedicated sub-networks running concurrently. Test and evaluation tools for CAN based networks are available for years, but they are mostly focused on test scenarios with up to two CAN networks, often based on the standard CAN hardware with a limited test functionality. They usually rely on the extensive support provided by a PC running a Windows based application software, which in many cases limits accurate test timing, especially when real-time response on the bus events is required. This paper presents a set of three unique instruments (CAN generator, CAN trigger unit, CAN controller) designed in form of IP functions. Arbitrary number of the IP functions can be used in FPGA based test tools supporting real-time test scenarios over "unlimited" number of CAN sub-networks simultaneously.

Paper deals with the modelling of the mechanism ensuring the start-up of a FlexRay network. The model has been created with the use of timed automata and verified. For this purpose the UPPAAL software tool has been used that allows the modelling of discrete event systems with the use of timed automata, and subsequently the verification of the model with the use of suitable queries compiled in the so called computation tree logic. This model can be used to look for incorrect settings of time parameters of communication nodes in the network that prevent network start-up and subsequently the start of the car. The existence of this model also opens the way for finding possible errors in the standard. On the basis of the model, the work gives a case study of the start-up mechanism behaviour verification in a FlexRay network consisting of three communication nodes.

The paper describes an unusual approach to diagnose standard ignition subsystem of fuel engines. All the information about real state conditions of the ignition coils and sparks is taken from simple measurement of power consumption transient of the electric control systems of engine. The transient is processed by continuous wavelet transformation (CWT). Result of the CWT is used for a classifier. Classifier is supposed to work in learning and diagnostic modes. The main output of the classifier is two disjoint states meaning correct and incorrect functional work of the engine ignition system. The described method is going to be used as a part of standard information equipment of vehicles. The method could bring saving the costs for automobile manufacturer.

An increasing number of Electronic Control Units in passenger cars and high communication traffic have led the car manufacturers to splitting a single CAN network into several dedicated sub-networks running concurrently. Test and evaluation tools for CAN based networks are available for years, but they are mostly focused on test scenarios with up to two CAN networks, often based on the standard CAN hardware with a limited test functionality. They usually rely on the extensive support provided by PC running a Windows based application software, which in many cases limits accurate test timing, especially when realtime response on the bus events is required. This paper presents a set of unique instruments (CAN generator, CAN trigger unit, time-triggered CAN controller) designed in form of IP functions. Arbitrary number of the IP functions can be used in FPGA based test tools supporting real-time test scenarios over "unlimited" number of CAN subnetworks simultaneously.

Tento článek se zabývá novým komunikačním standardem FlexRay, primárně určeným do automobilů pro tzv. x-by-wire aplikace. Text nejprve ve stručnosti čtenáře seznamuje s vlastnostmi standardu a mechanismy v něm probíhajícími. Hlavní zaměření je pak na reálnou komunikační FlexRay síť, která vznikla na katedře měření fakulty elektrotechnické ČVUT Praha, a její využití pro verifikaci FlexRay synchronizačního mechanismu.

Today's diagnostic systems used in vehicles are based on separate diagnostic subsystems for each electronic or electric device. The basic idea of the project is to develop a centralized diagnostic method to cover most of functional systems. The proposed method would expedite the overall testing time and bring other significant advantages such as savings on test equipment. This paper deals with engine lighting equipment testing technique.

V současné době dochází k značnému rozvoji v oblasti dálkové řízených létajících prostředků, bez přítomnosti pilota. Jejich výhodou je dlouhá výdrž nad rozlehlou kontrolovanou oblastí. Bezpilotní prostředky mohou být využívány pro vojenské účely např. ostraha hranic, nebo v civilním sektoru pro kontrolu např. stavu polí (USA, Brazílie) Tyto bezpilotní prostředky obsahují buď z části, nebo zcela automatický elektronický systém řízení přičemž pilot sedící v bezpečí řídícího stanoviště přikazuje pouze požadavky na změnu výšky, rychlosti nebo směru letu. Článek popisuje systémy podpory řízení bezpilotního prostředku Mamok Manta, který je vyvíjen firmou AVEKO Brno, odštěpným závodem LOM VTÚLaPVO ve spolupráci s katedrou měření ČVUT v Praze.

This paper presents a new method for sample point position measurement in the bit interval of Controller area network (CAN) nodes.

Chap. 4 - Modern Sensors Handbook (Intelligent Sensors and Sensor Networks)

Článek poskytuje přehled nabídky číslicových osciloskopů a DAQ systémů na trhu v České republice. Je zaměřen především na vlastnosti specifické pro nové přístroje obou kategorií.

CAN communication is nowadays the basic way for information exchange among the Electronic Control Units (ECUs) that control particular vehicle functionality. As the CAN is rather complex standard, the detailed testing of ECU behavior is necessary at all protocol layers of the communication stack. In order to simplify the testing and to reduce the human factor influence the automated test site has been designed and implemented, which realizes more than 50 physical, link and application protocol layer tests. The use of programmable logic for hardware implementation allows modifying the test site functionality without changes in a hardware structure. The time to run the complete test was reduced more than 10 times compared to previously used manual measurement and evaluation.

Improvement of Laboratory of Microprocessor Applications

The study branch concerning computer science and engineering (which offers the study programs of a number of Faculties of Electrical Engineering and Informatics) is often primarily focused on software engineering. It brings a tendency to minimize an amount of basic courses relevant to electrical engineering in this study branch. It concerns also the education in measurement and instrumentation. The paper describes the approach applied at the CTU in Prague, Faculty of Electrical Engineering to solve this matter. A content of lectures and labs of the basic course "Measurement in Digital Circuits" and briefly also of the optional course "Diagnostics of Digital Devices" is presented.

In this paper a method for sample point position measurement in the bit interval of Controller Area Network (CAN) nodes is presented. The position of sample point is an important parameter of CAN network node configuration, as it particularly influences the bit error rate and consequently frame error rate within the whole system. The measurement method, implementation of a specialized test instrument and the measured results evaluation are described, as well as validation procedure od the described method and its results.

V nabídce stále většího počtu firem se objevují moduly pro systémy VME a VXI. Na rozdíl od systémů na bázi ISA sběrnice, jejichž vývoj i výroba je v tuzemsku plně zvládnuta, jsou komponenty výše uvedených systémů poněkud komplikovanější a v tuzemsku se nevyrábějí. Zahraniční výrobky jsou poměrně drahé a přes stále rostoucí nabídku je většinou problematické nalézt vyhovující funkční a cenový kompromis při výběru modulů systému. Článek se zabývá především možnostmi, výhodami, ale i potencionálními nedostatky zákaznických řešení prvků VME a VXI systémů a zkušenostmi s jejich implementací.

Varianta VXIbus řešení, která se při zachování spolehlivosti, variability, univerzálnosti řešení, zpracování naměřených hodnot a robustnosti VXIbus systému cenou blíží k systémům střední třídy. Příčinou je využití standardně nabízených VXIbud modulů v kombinaci se zákaznickými VXIbus moduly podle potřeb konkrétní aplikace.

Přehled systémů pro měření, řízení a sběr dat a jejich implementace do tzv. otevřených systémů

Funkce rozhraní RS-485 pod vlivem burst impulsů

Ověření zkušeností s provozem sériové sběrnice RS 485 v průmaslovém prostředí

Trojosý magnetometr vyvinutý pro mapování časové závislosti jednotlivých složek rušivého mag.pole