Today's legislation on exhaust gas emissions for heavy duty diesel (HDD) vehicles is more stringent than ever and will be even more tough in the future. More over, in a few years HDD vehicles have to be equipped with OBD (On-Board Diagnostics). This place very high demands on the manufacturers to develop better engines and strategies for OBD. As an aid in the process models can be used. This thesis presents extensions of an existing diesel engine model in Matlab/Simulink to be able to simulate emissions during standardized european test cycles. Faults in the sensor and actuator signals are implemented into the model to find out if there is an increase or decrease in the emissions. This is used to create a fault tree where it can be seen why predefined emission thresholds are exceeded. The tree is an aid when developing OBD. The results from the simulations showed that almost no faults made the emissions cross the thresholds. The only interesting faults were faults in the ambient temperature sensor and the injection angle actuator. This means that the OBD-system only needs to monitor a few components which implies a smaller system and less work.

In a system like a Scania heavy duty truck, faultcodes (DTCs) are generated and stored locally in the ECUs when components, e.g. sensors or actuators, malfunction. Tests are run periodically to detect failure in the system. The test results are processed by the diagnostic system that tries to isolate the faulty components and set local faultcodes. Currently, in a Scania truck, local diagnoses are only based on local diagnostic information, which the DTCs are based upon. The diagnosis statement can, however, be more complete if diagnoses from other ECUs are considered. Thus a system that extends the local diagnoses by exchanging diagnostic information between the ECUs is desired. The diagnostic information to share and how it should be done is elaborated in this thesis. Further, a model of distributed diagnosis is given and a few distributed diagnostic algorithms for transmitting and receiving diagnostic information are presented. A basic idea that has influenced the project is to make the diagnostic system scalable with respect to hardware and thereby making it easy to add and remove ECUs. When implementing a distributed diagnostic system in networked real-time embedded systems, technical problems arise such as memory handling, process synchronization and transmission of diagnostic data and these will be discussed in detail. Implementation of a distributed diagnostic system is further complicated due to the fact that the isolation process is a non deterministic job and requires a non deterministic amount of memory.

<p>Diagnostic systems become more and more an important within the field of vehicle systems. This is much because new rules and regulation forcing the manufacturer of heavy duty trucks to survey the emission process in its engines during the whole lifetime of the truck. To do this a diagnostic system has to be implemented which always survey the process and check that the thresholds of the emissions set by the government not are exceeded. There is also a demand that this system should be reliable, i.e. not producing false alarms or missed detection. One way of producing such a system is to use model based diagnosis system where thresholds has to be set deciding if the system is corrupt or not. There is a lot of difficulties involved in this. Firstly, there is no way of knowing if the signals logged are corrupt or not. This is because faults in these signals should be detected. Secondly, because of strict demand of reliability the thresholds has to be set where there is very low probability of finding values while driving. In this thesis a methodology is proposed for setting thresholds in a diagnosis system in an experimental test engine at Scania. Measurement data has been logged over 20 hours of effective driving by two individuals of the same engine. It is shown that the result is improved significantly by using this method and the threshold can be set so smaller faults in the system reliably can be detected.</p>

<p>Today's legislation on exhaust gas emissions for heavy duty diesel (HDD) vehicles is more stringent than ever and will be even more tough in the future. More over, in a few years HDD vehicles have to be equipped with OBD (On-Board Diagnostics). This place very high demands on the manufacturers to develop better engines and strategies for OBD. As an aid in the process models can be used. </p><p>This thesis presents extensions of an existing diesel engine model in Matlab/Simulink to be able to simulate emissions during standardized european test cycles. Faults in the sensor and actuator signals are implemented into the model to find out if there is an increase or decrease in the emissions. This is used to create a fault tree where it can be seen why predefined emission thresholds are exceeded. The tree is an aid when developing OBD. </p><p>The results from the simulations showed that almost no faults made the emissions cross the thresholds. The only interesting faults were faults in the ambient temperature sensor and the injection angle actuator. This means that the OBD-system only needs to monitor a few components which implies a smaller system and less work.</p>

Στην παρούσα διπλωματική εργασία σχεδιάστηκε, μελετήθηκε και υλοποιήθηκε ένα σύστημα διαγνωστικών αυτοκινήτου ή αλλιώς ένα σύστημα On Board Diagnostics II (OBD-II), όπως είναι η διεθνής του ονομασία. Ένα τέτοιο σύστημα έχει καταστεί απαραίτητο, λόγω της πολυπλοκότητας των αυτοκινήτων σήμερα, σε μια ευρεία κατηγορία επαγγελματιών, που ξεκινάει από τους κατασκευαστές αυτοκινήτου μέχρι και το κάθε συνεργείο, αλλά και τον εκάστοτε ιδιώτη. Κύριοι στόχοι του είναι η πληροφόρηση του χρήστη για οποιαδήποτε παράμετρο του οχήματος και ο εντοπισμός και η ένδειξη τυχόν βλαβών. Για την επίτευξη των στόχων αυτών, σχεδιάστηκε και υλοποιήθηκε με τη μορφή πλακέτας ένα σύστημα το οποίο είναι υπεύθυνο για τη σωστή αποστολή και λήψη των μηνυμάτων μεταξύ του υπολογιστή και του οχήματος. Επιπλέον, αναπτύχθηκε το απαραίτητο λογισμικό για τη χρήση του συστήματος και όλων των δυνατοτήτων του. Για το σωστό έλεγχο τόσο του κυκλώματος όσο και του λογισμικού, χρησιμοποιήσαμε έναν προσομοιωτή ECU αυτοκινήτου. / In this diploma thesis, an On Board Diagnostics system (OBD-II) was studied, designed and created. This type of system is of utmost importance to a great variety of users such as professional engineers and individuals. Its main purposes are to inform the user about all the different parameters of the vehicle and to identify potential malfunctions. To accomplish these tasks, a PCB circuit was designed and manufactured, which is responsible for the correct transmission and reception of OBD-II messages between a developed PC software and the vehicle. In order to test the circuit and the designed application, an ECU Simulator was used.

Advances in engine oil technology and increased combustion efficiency has resulted in the longer oil intervals in vehicles. Current oil change interval practice only takes into account the mileage a vehicle has driven and does not consider other vehicle operations that affect oil life like extended idle. Routine oil sampling is one way to ensure optimal oil intervals, but the price continuous analysis can be prohibitive. It is possible to use on board diagnostic (OBD) data to correlate oil degradation to engine usage in order to develop an algorithm that is applicable to many vehicles. While much research has been conducted for light duty vehicles, little has been completed for heavy duty vehicles, in particular vehicles that idle a majority of their time. This study uses multiple heavy duty vehicles that are monitored by monthly routine oil analysis and logging of on board diagnostic data to determine the effects extended idle has on the wear rate of oil. The vehicles were used in their normal operation; this resulted in an average idle run time of 60% of run time and no less than 50% in a single vehicle. At each sample the quality of the oil and the operation of the engines were assessed. The results of the oil analysis showed very little degradation of oil. As expected, a negative correlation was seen in viscosity and total base number (TBN) but not abnormal when compared to base oil. Significant degradation was not seen even after using the vehicle passed the manufacturer recommended oil intervals. Analysis of engine operation showed that the temperature of the oil was optimal for 85% of idle operation. In addition, oil pressures at idle were sufficiently higher than the minimum pressure recommended by the manufacturer, but was less than half of the average in use oil pressure. The combination of low pressure and optimal temperature has resulted in little oil degradation. The results from the study have shown that extended idling in the study vehicles can be treated similar to long trip interval service for oil degradation. Additionally, extended idling did not result in abnormal engine wear or excessive contamination.

The main purpose of this project is to analyse used protocols in vehicles available under the OBD II specifications. In the project we will also focus on processing diagnostic data. We will design device for vehicle diagnostic. This device will be able to send processed data on external web server via Internet network. Obtained data will be saved on data server. Building of functional receiver will be the major part of master´s thesis.

The thesis deals with possibilities of application of VAG-COM PROFI diagnostic kit in forensic engineering. After defining a theoretical basis, according to possibilities of evaluation of technical condition of a vehicle, the thesis is focused on applying diagnostic methods using above mentioned diagnostic kit. With respect to opportunities of identification of driving parameters, possibility of acceleration measurement and estimation of engine power are introduced. Describing of methodology and making the final statement are contained in the thesis as a part of every single measurement.

The subject area of this project is IT security related to cars, specifically the security of devices connected through a cars OBD-II connector. The aim of the project is to see the security level of the AutoPi OBD-II unit and to analyse where potential vulnerabilities are likely to occur when in use. The device was investigated using threat modeling consisting of analysing the architecture, using the STRIDE model to see the potential attacks that could be implemented and risk assessments of the attacks using the DREAD model. After modelling the system, attempts of implementing attacks, with the basis in the threat modelling, were carried out. No major vulnerabilities were found in the AutoPi device but a MITM attack on the user was shown to be possible for an attacker to succeed with. Even though no major vulnerability was found IoT devices connected to cars might bring security concerns that needs to be looked into by companies and researchers. / Ämnesområdet för detta projekt är ITsäkerhet relaterad till bilar, mer specifikt säkerheten gällande enheter som kopplas in i en bils OBD-II-kontakt. Syftet med uppsatsen är att bedöma säkerhetsnivån på en OBD-II-enhet av modell AutoPi och att analysera var potentiella sårbarheter kan finnas i systemet. Enheten kommer att undersökas med hjälp av hotmodellering som består av att analysera arkitekturen, använda STRIDE-modellen för att upptäcka potentiella attackmetoder samt bedöma riskerna för attackerna med hjälp av DREAD-modellen. Efter det steget görs attackförsök utifrån resultaten från hotmodelleringen. Inga större sårbarheter hittades i AutoPi-enheten men en MITM-attack på användaren visades vara möjlig för en angripare att lyckas med. Ä ven fast inga större sårbarheter hittades kan IoT-enheter kopplade till bilar medföra säkerhetsbrister som företag och forskare måste se över.

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