Browse Topic: On-board diagnostics (OBD)

Items (297)

Analysis Techniques for Racecar Data Acquisition [mms update 07.03.25]

R-367To be published on 03/22/2099

Data acquisition has become an invaluable tool for establishing racecar - and car/driver - performance. Now that the ability exists to analyze each and every performance parameter for car and driver, accurate use of this data can provide a key advantage on the racetrack. This book provides a thorough overview of the varied methods for analyzing racecar data acquisition system outputs, with a focus on vehicle dynamics.

Segers, Jorge

Diagnostic Trouble Code Definitions

J2012_202511 (Current)

11/21/2025

This document supersedes SAE J2012 DEC2007, and is technically equivalent to ISO 15031-6:2010 with the exceptions described in 1.2. This document is intended to define the standardized Diagnostic Trouble Codes (DTC) that On-Board Diagnostic (OBD) systems in vehicles are required to report when malfunctions are detected. SAE J2012 may also be used for decoding of enhanced diagnostic DTCs and specifies the ranges reserved for vehicle manufacturer specific usage.

Vehicle E E System Diagnostic Standards Committee

On-Board Diagnostics Implementation Guide

J1939/03_202510 (Current)

10/1/2025

SAE J1939-03 provides requirements and guidelines for the implementation of on-board diagnostics (OBD) on heavy duty vehicles (HDV) using the SAE J1939 family of standards. The guidelines identify where the necessary information to meet OBD regulations may be found among the SAE J1939 document set. Key requirements are identified here to ensure the interoperability of OBD scan tools across individual OBD-compliant vehicles.Market-defined regulations permit the use of SAE J1939 to meet OBD requirements. Implementers are cautioned to obtain and review the specific regulations for the markets where their products are sold. This document is focused on guidelines and requirements to satisfy the State of California Air Resources Board (CARB), the authors of 13 CCR 1971.1, United States Environmental Protection Agency, Euro IV and V requirements from European Commission directives, and UN/ECE WP 29 GRPE WWH OBD Global Technical Regulation (GTR).

Truck Bus Control and Communications Network Committee

test 09/29/2022 2:00 pm

SAE-PP-077339/29/2022

test 09/29/2022 2:00 pm

Dongari, Madhukar

Minimum Operational and Maintenance Responsibilities for Aircraft Tire Usage

ARP5265C (Historical)

9/20/2021

This SAE Aerospace Recommended Practice (ARP) sets forth criteria for the installation, inflation, inspection, and maintenance of aircraft tires and the maintenance of the operating environment to ensure the safety of support personnel and the safe operation of the aircraft.

A-5C Aircraft Tires Committee

C0708.Multi7/8/2021

On-board diagnostics, required by governmental regulations, provide a means for reducing harmful pollutants into the environment. Since being mandated in 1996, the regulations have continued to evolve and require engineers to design systems that meet strict guidelines. This one day seminar is designed to provide an overview of the fundamental design objectives and the features needed to achieve those objectives for generic on-board diagnostics. The basic structure of an on-board diagnostic will be described along with the system definitions needed for successful implementation. Please note that because of proprietary considerations, this class does not provide details of algorithm design, algorithm performance, or algorithm application. The class will cover general OBD algorithm designs and the features required to promote sound OBD system design. Individuals desiring a more in-depth look at On-Board Diagnostics should consider attending SAE seminar ID# C0707 Designing On-Board Diagnostics for Light and Medium Duty Emissions Control Systems. By attending this seminar, you will be able to: Articulate the underlying design objectives of on-board diagnostic systems Apply the design features that all diagnostics need for successful implementation Apply basic design techniques to deal with variation Use a diagnostic design template in the development of an on-board diagnostic 1 Day .7 CEUs

Catalog of Landing Gear Systems and Suppliers

AIR5631A (Current)2/3/2021

The purpose of this document is to provide a listing for current commercial and military aircraft landing gear systems and their types and manufacturers. Data has been provided for the following commercial aircraft types; wide body jet airliners, narrow body jet airliners, and turboprop/commuter aircraft and the following military aircraft types; fighter, bomber, cargo, attack, surveillance, tanker and helicopter categories. The aircraft that have been included in this document are in operational service either with airlines, business, cargo or military operators. No information is presented for aircraft that are currently being developed or that are not in extensive usage. This document will provide an informational reference for landing gear engineers to access when evaluating other gear and aircraft systems. Future revisions of this document will add aircraft as they enter into service.

A-5 Aerospace Landing Gear Systems Committee

“Rds_on” Based OBD for Pre-Supply Fuel Pump Driver Modules

SAE-PP-001601/26/2021

In automotive electronics on-board diagnostics does the fault diagnosis and reporting. It provides the level of robustness required for the control electronics against various faults. The amount of diagnostic information available via on board diagnostics are depends on the type of vehicle. Pre-supply fuel pump is the component in the common rail hydraulic system. It pumps the fuel from the fuel tank to the inlet valve of the high pressure fuel pump. Electronic control unit synchronizes its operation with high pressure fuel pump. A dedicated driver module in the ECU controls the operation of pre-supply fuel pump. The driver module consist of an ASIC with internal voltage, current monitoring modules for the fault diagnosis and the pre-drivers to control external HS and LS power stages. The software part of the OBD programmed in the internal memory of the ASIC. The “Rds_on” of the power MOSFETs are used for the fault detection purpose. The module designed to operate in dual frequencies and variable duty cycles. It ensures the optimum hydraulic performance of the pump and provides maximum possible diagnostic coverage against various faults. The on-board diagnosis against the faults such as motor inrush current, rotor Lock, short circuit to ground, short circuit to battery, line to line fault (short circuit between high side and low side pins) and open load are discussed in this paper. The wiring harness impedance has significant influence on the fault detection duration. The wiring harness length depends on the position of ECU and pump in the vehicle. Pre-supply fuel pump normally immersed in the fuel tank and ECU normally kept either in the dash board or mounted on the body of engine. The resistance and inductance of the wiring harness are the functions of wire diameter and length. The below are the parameters influences the fault diagnostics of the driver module discussed in this paper. • Fault detection threshold (Vth), • The “Rds_on” of the MOSFET, • Fault current magnitude, • Frequency at which power stage operates, • Duty cycle, • Thermal response of the MOSFET, • Safe operating conditions, • Blind bands and MOSFET turn on/off delays. These parameters possesses typical relationships each another depending on the operating modes of engine and ambient conditions.

MobrxivNonAdmin, Lindsay

Marine Stern Drive and Inboard Spark-Ignition Engine On-Board Diagnostics Implementation Guide

J1939-5_202006 (Current)

6/30/2020

This document describes the application of the SAE J1939 recommended practices for compliance with on-board diagnostic malfunction detection system requirements for marine sterndrive and inboard spark ignition engines, as mandated by the California Air Resources Board (CARB). These Otto-cycle engines are not derived from automotive diesel-cycle engines.

Truck Bus Control and Communications Network Committee

Automated Diagnosis of Engine Misfire Faults Using Combination Classifiers

02-13-02-0007

6/26/2020

Existing on-board diagnostics vehicle systems can detect the existence of faults, but their diagnostic (fault isolation) capabilities are rather low. Extensions to on-board diagnostics are needed in order to provide a high degree of automated diagnostic support. In this context, we study in this article the problem of internal combustion engine misfires, which constitute a class of automotive faults known to be difficult to diagnose, and present a combination classifier that has excellent performance in classifying the various root causes of misfire faults. We first obtained real-life data and built a database consisting of 2,299 time instances of actual misfire and misfire-free cases. Fault data were captured on several different vehicle makes and models, with each misfire fault belonging to one of three different categories (air-intake, coil-ignition, and fuel-injection), further subdivided into a total of seven subcategories. We then developed a combination classifier (referred to as TMF, “Trees for MisFires”) and obtained its performance on the real-life misfire fault dataset. Extensive simulation results show that TMF outperforms a variety of other standard classifiers (whether single or ensemble) as well as other combination classifiers, both for “low-resolution” diagnosis (classification consisting of three misfire fault categories plus misfire-free) and “high-resolution” diagnosis (classification consisting of seven misfire fault subcategories plus misfire-free). Moreover, these results hold even when the training set is restricted to be a very small portion of the available dataset, which is a valuable asset of a realistic classifier.

Suda, Jessica L., Kagaris, Dimitri

Application Layer - Diagnostics

J1939/73_202006 (Historical)6/9/2020

SAE J1939-73 defines the SAE J1939 messages to accomplish diagnostic services and identifies the diagnostic connector to be used for the vehicle service tool interface. Diagnostic messages (DMs) provide the utility needed when the vehicle is being repaired. Diagnostic messages are also used during vehicle operation by the networked electronic control modules to allow them to report diagnostic information and self-compensate as appropriate, based on information received. Diagnostic messages include services such as periodically broadcasting active diagnostic trouble codes, identifying operator diagnostic lamp status, reading or clearing diagnostic trouble codes, reading or writing control module memory, providing a security function, stopping/starting message broadcasts, reporting diagnostic readiness, monitoring engine parametric data, etc. California-, EPA-, or EU-regulated OBD requirements are satisfied with a subset of the specified connector and the defined messages.

Truck Bus Control and Communications Network Committee

Virtual Switches and Indicators in Automotive Displays

2020-01-13624/14/2020

This paper presents recent advances in automotive microprocessor, operating system, and supporting software technology that supports regulatory and/or functional safety graphics within vehicle cockpit displays. These graphics include “virtual switches” that replace physical switches in the vehicle, as well as “virtual indicators” that replace physical indicator lights. We discuss the functional safety design process and impacts to software and hardware architecture as well as the software design methods to implement End-To-End [E2E] network protection between different ECUs and software processes. We also describe hardware monitoring requirements within the display panel, backlighting, and touch screen and examine an example system design to illustrate the concepts.

Rush, Scott

Data-Driven Framework for Fuel Efficiency Improvement in Extended Range Electric Vehicle Used in Package Delivery Applications

2020-01-05894/14/2020

Extended range electric vehicles (EREVs) are a potential solution for fossil fuel usage mitigation and on-road emissions reduction. The use of EREVs can be shown to yield significant fuel economy improvements when proper energy management strategies (EMSs) are employed. However, many in-use EREVs achieve only moderate fuel reduction compared to conventional vehicles due to the fact that their EMS is far from optimal. This paper focuses on in-use rule-based EMSs to improve the fuel efficiency of EREV last-mile delivery vehicles equipped with two-way Vehicle-to-Could (V2C) connectivity. The method uses previous vehicle data collected on actual delivery routes and machine learning methods to improve the fuel economy of future routes. The paper first introduces the main challenges of the project, such as inherent uncertainty in human driver behavior and in the roadway environment. Then, the framework of our practical physics-model guided data-driven approach is introduced. For vehicles with small amounts of prior data, a Bayesian method is used to adjust a control parameter in the EMS offline for each vehicle with introduced prior information derived from large numbers of trips from other vehicles in the fleet. For vehicles with many delivery trips, a reinforcement learning algorithm is used to optimize the parameter in real-time without requiring future information of the trip. Although our data-driven framework cannot achieve a globally optimal solution with respect to the fuel efficiency, it provides a systematic and immediate solution for in-use EREVs used for package delivery with a very low computation cost and no change of vehicle hardware. Also, this framework is ready to be extended for further fuel economy improvements if more information is available from advanced transportation infrastructures like Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) connectivity.

Wang, Pengyue, Northrop, William

Requirements for Built-in Service Port for On-Board Diagnostics

J2744_202003 (Current)3/11/2020

This document presents the requirements for a built-in service port to be used in vehicles intended to comply with Enhanced Evaporative Emissions Requirements. The primary function of the Service Port (Valve Assembly-Evaporative Emission Canister Purge Harness Service) is to provide non-destructive access to the evaporative emissions system to enable testing of the integrity of the system. The Service Port is used to introduce air pressure or fuel vapors into, or evacuates them out of, the system. This access may be used for the following evaluations: • Evaporative System Certifications Canister Loading and Purging • End-of-line Testing System Integrity • Service (e.g. OBD MIL on) Leak Location and Repair Verification • In-Use Compliance Testing Canister Loading and Purging • Inspection/Maintenance Testing System Integrity and Purge Check

Fuel Systems Standards Committee

Permanently or Semi-Permanently Installed Diagnostic Communication Devices, Security Guidelines

J3005-2_202003 (Current)3/4/2020

The scope of the document is to define the cyber-security best practices to reduce interference with normal vehicle operation, or to minimize risk as to unauthorized access of the vehicle's control, diagnostic, or data storage system; access by equipment (i.e., permanently or semi-permanently installed diagnostic communication device, also known as dongle, etc.) which is either permanently or semi-permanently connected to the vehicle's OBD diagnostic connector, either SAE J1939-13, SAE J1962, or other future protocol; or hardwired directly to the in-vehicle network. This document only specifies requirements and guidance for those diagnostic communication devices and not for the vehicle. Refer to SAE J3138 for requirements for the vehicle side.

Vehicle E E System Diagnostic Standards Committee

Vehicle Application Layer

J1939/71_202002 (Historical)2/11/2020

The SAE J1939 communications network is developed for use in heavy-duty environments and suitable for horizontally integrated vehicle industries. The SAE J1939 communications network is applicable for light-duty, medium-duty, and heavy- duty vehicles used on-road or off-road, and for appropriate stationary applications which use vehicle derived components (e.g., generator sets). Vehicles of interest include, but are not limited to, on-highway and off-highway trucks and their trailers, construction equipment, and agricultural equipment and implements. SAE J1939-71 is the SAE J1939 reference document for the conventions and notations that specify parameter placement in PGN data fields, the conventions for ASCII parameters, and conventions for PGN transmission rates. This document previously contained the majority of the SAE J1939 data parameters and messages for information exchange between the ECU applications connected to the SAE J1939 communications network. It also contained reference figures and reference information. The data parameters (SPNs), messages (PGNs), reference figures, and information previously published within this document are now published in SAE J1939DA. There are several SAE J1939-7X documents that collectively define all of the SAE J1939 application layer data parameters and messages. Diagnostic services and some industry-specific data parameters and messages are documented within other SAE J1939-7X application layer documents. An ECU may simultaneously use and support data parameters and messages from multiple SAE J1939-7X application layer documents.

Truck Bus Control and Communications Network Committee

Digital Twins for Prognostic Profiling

2019-28-245611/21/2019

Ability to have least failures in products on the field with minimum effort from the manufacturers is a major area of focus driven by Industry 4.0 initiatives. Amidst traditional methods of performing system/subsystem level tests often does not enable the complete coverage of a machine health performance predictions. This paper highlights a workable workflow that could be used as a template while considering system design especially employing Digital Twins that help in mimicking real-life scenarios early in the design cycle to increase product’s reliability as well as tend to near zero defects. With currently available disruptive technologies, systems integrated multi-domain 'mechatronics' systems operating in closed-loop/close-interaction. This poses great challenge to system health monitoring as failure of any component can trigger catastrophic system failures. It may be the reason that component failures, as per some aerospace reports, are found to be major contributing factors to aircraft loss-of-control. Essentially, it is either too expensive or impossible to monitor every component or subsystem of a complex machine and the current state of the Integrated Health Monitoring Systems seem to be quite inadequate. In this paper, we propose an approach that combines the best of the diagnostics and feature extraction techniques coupled with Artificial Intelligence as a solution to address the challenges of Prognostics Health Management (PHM) for complex systems. The paper also documents a standard procedure to apply the right technologies/tools at every stage so that a clear process can be applied for any similar complex system across the product development life cycle. In this paper we derive the health status of subsystems by looking at system level responses [1]. Distinguishing features are derived from the overall system level response through feature extraction methodologies and then fed into decision making frameworks that are implemented using both Convolutional Neural Networks [7, 18, 19], Machine Learning [4] and Deep Learning. Models are trained with distinguishable features through system simulations [20]. Employing rightly designed ML models provide the ability of classifying the failure modes as well as to analyze system faults/responses. Predictive modelling techniques are applied to the ML processed data to deliver useful prognostics on the criticality of the failure mode, RUL of the components/subsystems while system is in operation can be determined. The proposed concept can be easily adapted to various systems from varying domains [2]. The methodology evolved in this work can be easily extended for various use cases for instance in the Transportation domain the user can get alerts not only of failures ahead of time but also the remaining useful lifer as well as possible causes of such a failure. This would let prevent downtime of the overall vehicle/fleet and thereby ensures smooth operation of the entire service. As a case study, the present work demonstrates the a DPHM solution applied to electrical energy generator where failure mode effects of subsystems and their effect on the overall system performance are studied using Modeling and Simulation techniques. The overall work would finally lead in demonstrating a working recommendation/advisory system that understand the behavior as if it was a pure Digital Twin [24] and thereby giving a quick turn around for different use cases like study/analysis/what if/predict behavior under various operating conditions with a high level of confidence before the changes are tried on a real system.

Thukaram, Painuri, Mohan, Sreeram

Tire Performance Terminology

J2047_201911 (Current)

11/14/2019

This terminology aims to encompass all terms and definitions pertaining to the road performance of pneumatic tires designed for over-the-highway use, such as passenger car, light truck, truck and bus, and motorcycle tires. Not included are terms specific to the performance of agricultural, aircraft, industrial, and other off-highway tires. However, many terms contained in this document also apply to non-highway tires.

Highway Tire Committee

Development of Data Acquisition and Analysis System: Telemetry in Automotive

2019-28-007510/11/2019

Digital data extraction is the most important and advance informative system that are embedded in the modern world functioning machinery to acquire the most precise feedback about the real-time operational situation of the machine to the control centre of operation. This data that is acquired from the machinery can be used to increase the efficiency, operational timing, production-cost and the overall human effort that is required for the operation. This paper focuses on the development on the advanced telemetry system that is capable to acquire real-time data of the modern vehicle wirelessly during its motion. A mobile automotive telemetry system for installation on-board a vehicle, includes: diagnostic structure for monitoring operational functions of the vehicle and generating operational information; memory for storing the generated operational information; and a server, in communication with the diagnostic structure and the memory. The server includes: (a) structure to receive a request from a remote client for the generated operational information; (b) structure to retrieve the generated operational information from the memory; and (c) structure to transmit the generated operational information to the remote client.

Rastogi, Divyansh, Kumar, Gokul, Naiju, Chooriyaparambil Damodaran

E/E Data Link Security

J2186_201907 (Current)7/12/2019

Vehicle E E System Diagnostic Standards Committee

J1979-DA, Digital Annex of E/E Diagnostic Test Modes

J1979DA_201905 (Historical)5/8/2019

On-Board Diagnostic (OBD) regulations require passenger cars, and light and medium duty trucks, to support communication of a minimum set of diagnostic information to off-board “generic” test equipment. This document specifies the diagnostic data which may be required to be supported by motor vehicles and external test equipment for diagnostic purposes which pertain to motor vehicle emission-related data. SAE J1979 was originally developed to meet U.S. OBD requirements for 1996 and later model year vehicles. ISO 15031 5 was based on SAE J1979 and was intended to combine the U.S. requirements with European OBD requirements for 2000 and later model year vehicles.

Vehicle E E System Diagnostic Standards Committee

A Resonant Capacitive Coupling WPT-Based Method to Power and Monitor Seat Belt Buckle Switch Status in Removable and Interchangeable Seats

2019-01-04654/2/2019

In this study, we present an intelligent and wireless subsystem for powering and communicating with three sets of seat belt buckle sensors that are each installed on removable and interchangeable automobile seating. As automobile intelligence systems advance, a logical step is for the driver’s dashboard to display seat belt buckle indicators for rear seating in addition to the front seating. The problem encountered is that removable and interchangeable automobile seating outfitted with wired power and data links are inherently less reliable than rigidly fixed seating, as there is a risk of damage to the detachable power and data connectors throughout end-user seating removal/re-installation cycles. The present study tackles this issue through outfitting three removable and interchangeable rear seat assemblies with resonant capacitive coupling wireless power transfer as to power each rear seat across a variable gap between the interior paneling and that side of the seat closest to the interior paneling. A fundamental design challenge this system presented was the need to develop a rugged method to account for different sizes of seating, and hence to accommodate variable wireless power gaps. This issue was addressed via use of impedance matching technology to present a nearly constant load impedance to the dc-to-radiofrequency power inverter. The wirelessly received power enabled additional electronics added to the rear seat assemblies to wirelessly communicate the seat belt buckle states to a central hub where it was displayed via a custom graphical interface. Our approach involved the visibly imperceptible integration of resonant capacitively-coupled transmitting and receiving antennae behind the interior paneling for the transmitter and underneath the outer fabric of the rear seating. The resulting subsystem demonstrated the ability to power both the seat belt buckle switches and wireless communication over a range of wireless power gaps.

Cuddihy, Mark, Pottle, Brian

Improvement of the Resilience of a Cyber-Physical Remote Diagnostic Communication System against Cyber Attacks

2019-01-01124/2/2019

In the near future, vehicles will operate autonomously and communicate with their environment. This communication includes Vehicle-to-Vehicle (V2V), Vehicle-to-Infrastructure (V2I) communication, and comunication with cloud-based servers (V2C). To improve the resilience of remote diagnostic communication between a vehicle and external test equipment against cyberattacks, it is imperative to understand and analyze the functionality and vulnerability of each communication system component, including the wired and wireless communication channels. This paper serves as a continuation of the SAE Journal publication on measures to prevent unauthorized access to the in-vehicle E/E system [9], explains the components of a cyber-physical system (CPS) for remote diagnostic communication, analyzes their vulnerability against cyberattacks and explains measures to improve the resiliance.

Subke, Peter, Moshref, Muzafar

Security Mechanisms Design of Automotive Gateway Firewall

2019-01-04814/2/2019

Automotive security has become one of important topics in recent years under new automotive Electronic and Electrical Architecture (EEA). With the development of Intelligent Connected Vehicle (ICV), it has become possible to hack an automotive through in-vehicle networks. The introduction of Information Communications Technology (ICT) brings more risk threats to automotive. Researchers have shown that an attacker can easily tamper with many automotive functions via On-Board Diagnostic II (OBD-II) or In-Vehicle Infotainment (IVI). In order to protect automotive against malicious attacks, automotive security risks were analyzed and then security mechanisms based on network firewall were designed in this paper. Automotive network firewall is a security system that monitors and controls incoming and outgoing network traffics of automotive based on predetermined security rules. The main functions of network firewall include packet filter, anti-DoS and access control. Because of deferent security requirements of in-vehicle networks, CAN/FD and Ethernet were divided into two domains respectively. Packet filter mechanisms were designed to monitor CAN/FD, in which security level and time delay were considered. Ethernet firewall mechanisms were designed based on Stateful Packet Filter (SPF) technology. Beside packet filter mechanisms, anti-DoS and access control mechanisms were also designed. Security Real Time Operating System (SRTOS) was introduced to ensure lower layer security. Considering the ECU constraint, Hardware Security Module (HSM) is chosen to implement cryptography function. At last, proposed automotive network firewall were implemented base on a multicore MCU with HSM. The system is evaluated in several aspects such as packet throughput, time delay, anti-attack and memory usage. The evaluation results show that the automotive network firewall is effective and efficient.

Luo, Feng, Hou, Shuo

2019 Ram Chassis Cab: More capability, more driver-assist tech

19TOFHP04_124/1/2019

The 2019 Ram 3500, 4500, and 5500 Chassis Cab commercial trucks herald class-leading capability in towing, payload, and Gross Combined Weight Ratings (GCWR). “We drove our engineers bonkers to get the very best,” quipped Jim Morrison, head of Ram Brand at FCA North America. Morrison spoke with Truck & Off-Highway Engineering at the 2019 Chicago Auto Show following the global debut of the 2019 Ram Chassis Cab, which claims segment-leading towing of up to 35,220 lb (15,975 kg). It has the segment's highest GCWR (a combined truck, load and trailer weight) at 43,000 lb (19,504 kg), a 4,500-lb (2,041-kg) increase over the 2018 model.

Buchholz, Kami

CAN-Bus Remote Monitoring: Standalone CAN Sensor Reading and Automotive Diagnostics

12-02-01-00032/8/2019

A vehicle may be a font of data for some applications in safety, maintenance, and entertainment systems, once its electronic control units are connected to each other by a Controller Area Network (CAN) bus. By plugging a compatible device on the vehicle onboard diagnostics interface, reading raw data or conducting automotive diagnostics by International Standardization Organization 15765 and Society of Automotive Engineers J1979 is possible. The usual low-cost CAN data acquisition devices do not allow the connection to a cloud service for remote monitoring. Looking at this issue, this work proposes a low-cost NodeMCU CAN shield for data acquisition which is able to read the CAN frame of a Steering Angle Sensor, in Scenario 1, and standardized information from a vehicle such as its speed, identification number, and engine coolant temperature by automotive diagnostics, in Scenario 2. Both vehicle and standalone sensor data will be made available to the system user by the Thinger.io® Internet-of-Things platform by means of a smartphone 4G internet connection, aiming at remote CAN sensor diagnostics and vehicle monitoring.

Stevan Jr., Sergio Luiz, Farinelli, Felipe Adalberto

OBD Traceability Matrix

J1939-90_201902 (Historical)2/5/2019

This Information Report is intended to supplement the J1939 documents by offering the application of SAE RP J1939 to OBD data communications in a form that can be sorted and searched for easier use. It is NOT intended as a substitute for the actual regulations and standards documents, and any discrepancies between this document and the published documents must be resolved in favor of the published documents. This spreadsheet outlines elements in ARB OBD II and HD OBD requirements and identifies which J1939 SPNs and messages may be used to satisfy the datastream, readiness, in-use ratio, and test results requirements.

Truck Bus Control and Communications Network Committee

Application Layer - Diagnostics

J1939/73_201901 (Historical)1/31/2019

SAE J1939-73 Diagnostics Application Layer defines the SAE J1939 messages to accomplish diagnostic services and identifies the diagnostic connector to be used for the vehicle service tool interface. Diagnostic messages (DMs) provide the utility needed when the vehicle is being repaired. Diagnostic messages are also used during vehicle operation by the networked electronic control modules to allow them to report diagnostic information and self-compensate as appropriate, based on information received. Diagnostic messages include services such as periodically broadcasting active diagnostic trouble codes, identifying operator diagnostic lamp status, reading or clearing diagnostic trouble codes, reading or writing control module memory, providing a security function, stopping/starting message broadcasts, reporting diagnostic readiness, monitoring engine parametric data, etc. California-, EPA-, or EU-regulated OBD requirements are satisfied with a subset of the specified connector and the defined messages.

Truck Bus Control and Communications Network Committee

Optional Pass-Thru Features

J2534/2_201901 (Current)1/16/2019

SAE J2534-1 defines a standard vehicle network interface that can be used to reprogram emission-related control modules. However, there is a need to support vehicles prior to the 2004 model year, as well as non-emission related control modules. The SAE J2534-2 document meets these needs by detailing extensions to an SAE J2534-1 specification. It is not required for an interface to be fully compliant with SAE J2534-1 specification to implement some of the features specified in this document. Together, these extensions provide the framework for a common interface to protect the software investment of the Vehicle OEMs and Scan Tool manufacturers. Only the optional features will be described by this document and are based on the December 2004 publication of SAE J2534-1.

Vehicle E E System Diagnostic Standards Committee

Securing the Secret Key

2019-01-00971/16/2019

Recent advances in automotive technologies have paved way to a new era of connectivity. Advanced Driver Assistance Systems are getting deployed in automobiles; many companies are developing driverless cars; connected cars are no more a work of mere research. [1] Vehicle manufacturers are developing ways to interface mobile devices with vehicles. However, all these advances in technology has introduced security risks. Unlike traditional computing systems, the security risk of an automobile can be fatal and can result in loss of lives [2]. The in-vehicle network of an automobile was originally designed to operate in a closed environment and hence network security was not considered during its design [3]. Several studies have already shown that an in-vehicle network can be easily compromised and an intruder can take full control of the vehicle. Researchers are working on various ways to solve this problem. Securing the in-vehicle communication by encrypting the messages is one such way. This depends on the strength of the secret key used to encrypt the messages. In an automobile, these secret keys will be inside the automobile itself. If the in-vehicle network is compromised, then the secret keys will get exposed to intruders. There should be mechanisms to secure the secret keys. In this paper, we propose a way of securing the secret key for automotive network.

SS, Narendra Kumar

Management of RAM Fault for Safety Applications

2019-26-03651/9/2019

As safety compliance (ISO 26262) has become a norm for automotive embedded software development, the OEMs and Tier1 are pushed to follow the safety guidelines during hardware, software development process. This demands the microcontroller to not only detect internal faults but also find the exact root cause of the failure and have a self-healing mechanism. This paper presents proposed fault detection, injection, testing and shows comparison of microcontroller fault handling with respect to ISO26262 safety standard between proposed method and traditional method by giving the example of RAM test. Also gives an overview of software implementation of this concept as per AUTOSAR standard.

Ganapathi, Anavaratha Selvan

Digital Annex of Diagnostic Trouble Code Definitions and Failure Type Byte Definitions

J2012DA_201812 (Historical)12/19/2018

The J2012 Digital Annex of Diagnostic Trouble Code Definitions Spreadsheet provides DTC information in an excel format for use in your organization's work processes. The column headings include the same information as contained in the J2012 standard. Information in the excel spreadsheet will be updated several times annually, and the spreadsheet includes a column heading denoting which DTC have been updated in the current version.

Vehicle E E System Diagnostic Standards Committee

Cybersecurity Considerations for Heavy Vehicle Event Data Recorders

11-01-02-000612/14/2018

Trust in the digital data from heavy vehicle event data recorders (HVEDRs) is paramount to using the data in legal contests. Ensuring the trust in the HVEDR data requires an examination of the ways the digital information can be attacked, both purposefully and inadvertently. The goal or objective of an attack on HVEDR data will be to have the data omitted in a case. To this end, we developed an attack tree and establish a model for violating the trust needed for HVEDR data. The attack tree provides context for mitigations and also for functional requirements. A trust model is introduced as well as a discussion on what constitutes forensically sound data. The main contribution of this article is an attack tree-based model of both malicious and accidental events contributing to compromised event data recorder (EDR) data. A comprehensive list of mitigations for HVEDR systems results from this analysis.

Daily, Jeremy, Gardiner, Ben

Data Acquisition from Light-Duty Vehicles Using OBD and CAN

R-45811/15/2018

Modern vehicles have multiple electronic control units (ECU) to control various subsystems such as the engine, brakes, steering, air conditioning, and infotainment. These ECUs are networked together to share information directly with each other. This in-vehicle network provides a data opportunity for improved maintenance, fleet management, warranty and legal issues, reliability, and accident reconstruction. Data Acquisition from Light-Duty Vehicles Using OBD and CAN is a guide for the reader on how to acquire and correctly interpret data from the in-vehicle network of light-duty (LD) vehicles. The reader will learn how to determine what data is available on the vehicle's network, acquire messages and convert them to scaled engineering parameters, apply more than 25 applicable standards, and understand 15 important test modes. Topics featured in this book include: • Calculated fuel economy • Duty cycle analysis • Capturing intermittent faults Written by two specialists in this field, Richard P. Walter and Eric P. Walter of HEM Data, the book provides a unique roadmap for the data acquisition user. The authors give a clear and concise description of the CAN protocol plus a review of all 19 parts of the SAE International J1939 standard family. Data Acquisition from Light-Duty Vehicles Using OBD and CAN is a must-have reference for product engineers, service technicians fleet managers and all interested in acquiring data effectively from the light-duty vehicles.

Walter, Eric, Walter, Richard

Detection of Lane-Changing Behavior Using Collaborative Representation Classifier-Based Sensor Fusion

09-06-02-001010/29/2018

Sideswipe accidents occur primarily when drivers attempt an improper lane change, drift out of lane, or the vehicle loses lateral traction. In this article, a fusion approach is introduced that utilizes data from two differing modality sensors (a front-view camera and an onboard diagnostics (OBD) sensor) for the purpose of detecting driver’s behavior of lane changing. For lane change detection, both feature-level fusion and decision-level fusion are examined by using a collaborative representation classifier (CRC). Computationally efficient detection features are extracted from distances to the detected lane boundaries and vehicle dynamics signals. In the feature-level fusion, features generated from two differing modality sensors are merged before classification, while in the decision-level fusion, the Dempster-Shafer (D-S) theory is used to combine the classification outcomes from two classifiers, each corresponding to one sensor. The results indicated that the feature-level fusion outperformed the decision-level fusion, and the introduced fusion approach using a CRC performs significantly better in terms of detection accuracy, in comparison to other state-of-the-art classifiers.

Gao, Jun, Murphey, Yi Lu

Effects of Environmental Parameters on Real-World NOx Emissions and Fuel Consumption for Heavy-Duty Diesel Trucks Using an OBD Approach

2018-01-18179/10/2018

OBD (On-Board Diagnostic) test system is applied to research influences of environmental parameters (altitude and environment temperature) on real-world NOx emission and fuel consumption for heavy-duty diesel trucks in this paper. The research results indicate that altitude and environment temperature have great influence on NOx emission rate and fuel consumption. High altitude in range of 3000~4000 m results in NOx emission rate is lower than low and moderate temperature because of air intake amount decreasing. However the fuel consumption rate is higher than lower altitude because altitude influences real-time changes of air inflow and combustion conditions in the cylinder of the engine. NOx emission rate and fuel consumption is more stable at different vehicle speed, VSP and RPM at high altitude, and NOx emission rate fluctuate dramatically at low and moderate altitude. The fuel consumption rate is higher at 10~20 °C than that at lower and higher temperature. The environment temperature of 20~35 °C provides beneficial conditions for NOx production and deteriorates emission, and the environment temperature of −10~10 °C provides oxygen enrichment environment because of low temperature and high air density, so increases in production amount of NOx. Effects of altitude and environment temperature on NOx emission rate and fuel consumption rate show an opposite tendency. Compared with fuel consumption rate, NOx emission rate is more sensitive to vehicle speed, VSP and rotating speed.

Zhou, Hua, Zhao, Hongwei, Feng, Qian, Yin, Zenghui, Li, JIngyuan, Qin, Kongjian, Li, Mengliang, Cao, Lijuan

On Board Diagnostics (OBD) for Multi Topology Hybrid Electric Powertrain Architectures

2018-01-18279/10/2018

OBD is extended to electric powertrain components in Hybrid Electric Vehicle (HEV) architectures to monitor all components which influence vehicle emissions and electrical energy consumption. Besides main electric components, like battery, inverter, electric machines including their thermal management, other electric powertrain components and systems need to be evaluated as part of comprehensive component monitoring. The multiple possible HEV topologies require a complex assessment regarding the OBD relevance decisions of the electric drivetrain components or systems. In addition, specificities to OBD perimeter design in the hybrid architecture need to be appropriately chosen. This paper analyzes in detail the OBD regulation requirements for electric propulsion components as in the US regulation, which is an envelope for major global markets like Europe, China, Japan and Korea. Typical hybrid topologies from the literature and FEV’s comprehensive library are used as citation in this study. The monitors from these topologies are assessed for OBD relevance based on regulation requirements and the approach is detailed in this paper. The assessment is extended to safety relevant monitors, which are not part of traditional powertrain systems. The in-use performance ratio needs to be calculated for non-continuous monitors. The arithmetic between on-road driving, utility factor and frequency of non-continuous monitoring is also included. An efficient OBD development approach is elaborated for electric propulsion components in an HEV architecture. This covers requirement analysis, assessment approach for different types of input, output and functional monitors and concludes with an efficient validation approach.

Soundara Rajan, Ragupathi, Ferzli, Michel, Richert, Felix, Weem, Dirk Van Der

Serial Control and Communications Heavy Duty Vehicle Network - Top Level Document

J1939_201808 (Historical)8/20/2018

This top level document provides a general overview of the SAE J1939 network and describes the subordinate document structure. This document includes definitions of terms and abbreviations which are used among the various SAE J1939 subordinate documents.

Truck Bus Control and Communications Network Committee

Guidelines for Testing and Support of Aerospace, Fiber Optic, Inter-Connect Systems

ARP5061A (Current)8/16/2018

ARP5061A provides guidelines for optical performance testing of short haul fiber optic inter-connection systems used in aerospace vehicles. The focus of this document is to introduce the proper testing tools and establish common pre- and post-installation test methods and troubleshooting methodologies.

AS-3 Fiber Optics and Applied Photonics Committee

Early Acquisition and Preservation of Information in a Motor Vehicle Crash

J1674_201807 (Current)7/12/2018

The purpose of this SAE Recommended Practice is to offer simplified and prioritized guidelines for collecting and preserving on-scene data related to motor vehicle crashes. It is intended that these guidelines improve the effectiveness of data collection, which will assist subsequent analysis and reconstruction of a particular crash. This document is intended to guide early data collectors whose objectives include documenting information related to the crash. It may be used by law enforcement personnel, safety officials, insurance adjusters and other interested parties. This document identifies categories of scene physical features that deteriorate relatively quickly and recommends documentation task priorities. Detailed methods of collecting data are not part of this document. However, some widely used methods are described in the references in Section 2.

Data Collection and Archiving Standards Committee

A Robust Wheel Slip Control Design with Radius Dynamics Observer for EV

10-02-02-00096/18/2018

In order to improve the safety and dynamic performance of electric vehicles equipped with four in-wheel electric motors, and prevent the wheels from locking or slipping when braking or accelerating, a new longitudinal control strategy which combines ASR traction and ABS braking control is proposed using an observation algorithm of effective radius for four wheel of electric vehicle. Using the electric motor torques as the unique actuator signal sources, this combined ASR/ABS can act as acceleration slip regulation (ASR) by preventing the wheels from slipping during acceleration and as an antilock braking system (ABS) by preventing the wheels from getting locked during braking. A variation of effective radius of the wheel’s tire can have an incidence on the longitudinal and lateral control. Moreover, the wheel effective radius observer based on high order sliding mode approach using the information of the electric motor torques and the angular velocities is used in the combined ASR/ABS systems. First, adjusting the motor torque and based on Fuzzy logic control, the acceleration slip regulation (ASR) is designed to maintain the wheel slip in the optimal range using the angular acceleration and slip rate. Second, for limiting the wheel slip by adjusting the motor torque the sliding mode control is used. Several Matlab/Simulink simulation tests will be carried out to validate the effectiveness of the proposed controller.

Hartani, Kada, Khalfaoui, Mohamed, Merah, Abdelkader, Aouadj, Norediene

Characterization, Conducted Immunity

J2628_201806 (Current)6/12/2018

The methods included in this document are: a Voltage-Temperature Design Margins. b Voltage Interruptions and Transients. c Voltage Dropouts and Dips. d Current Draw Under a Number of Conditions. e Switch Input Noise These methods are best applied during the Development stage but can be used at all stages (e.g., Pre-Qualification, Qualification or Conformity).

Electromagnetic Compatibility (EMC) Standards

Evaluation of Hitachi Electric Vehicle Combined Battery System Lifespan in India

2018-01-04474/3/2018

We have developed a drive cycle (DC) to test Hitachi’s combined battery system (CBS) for electric vehicles (EVs) having battery lifespan enhancements. Conventionally EV batteries consist of high energy density cells, and we call them as energy cells (EC). A major issue with the EVs is high operational costs mainly due to short lifespan of the ECs. CBS almost doubles the EC and thus overall battery system lifespan, as per the evaluation over a WLTP based method. We want to test the CBS under Indian conditions which has predominantly hot weather, and traffic jam scenarios. Battery deterioration and thus its lifespan is sensitive to traffic conditions and ambient temperature. Hence, it was needed to evaluate the CBS over an Indian DC and use 40°C as ambient temperature. However, it was difficult to carry out the tests since there is no standard Indian DC for small / light weight four wheelers. Hence, we decided to synthesize a DC and collected over 1.5 million OBD data samples from four cars driven along different routes within Bangalore city. We propose a novel method to synthesize DC. We evaluate our method through statistical and frequency based similarity between the synthesized DC and OBD data. Finally, using the synthesized DC it was recognized that the battery lifespan could be enhanced by a factor of 2 through CBS over EC alone, for Indian conditions also. However, lifespan under the Indian conditions is reduced by a factor of 0.72 of the corresponding WLTP based lifespan estimates.

Chandra, Rishi, Yamauchi, Shin

An Innovative Design of In-Tire Energy Harvester for the Power Supply of Tire Sensors

2018-01-11154/3/2018

With the development of intelligent vehicle and active vehicle safety systems, the demand of sensors is increasing, especially in-tire sensors. Tire parameters are essential for vehicle dynamic control, including tire pressure, tire temperature, slip angle, longitudinal force, etc.. The diversification and growth of in-tire sensors require adequate power supply. Traditionally, embedded batteries are used to power sensors in tire, however, they must be replaced periodically because of the limited energy storage. The power limitation of the batteries would reduce the real-time data transmission frequency and deteriorate the vehicle safety. Heightened interest focuses on generating power through energy harvesting systems in replace of the batteries. Current in-tire energy harvesting devices include piezoelectric, electromagnetic, electrostatic and electromechanical mechanism, whose energy sources include tire deformations, vibrations and rotations. Through comparison, in-tire energy harvesting systems on basis of the electromagnetic induction principle have the advantage of relatively high energy density. Based on electromagnetic induction, this paper designs a novel design of in-tire energy harvester, taking use of the tire deformation when the tire contacts the ground. This paper describes the innovative design and builds the simulation model of magnetic field, integrated circuit, interaction between magnet and coils with Simulink. This work optimizes the parameters of the design according to the simulation, including the size of magnet, coils, materials, etc.. The induced voltage and power output have been discussed under different driving conditions, taking account of various vehicle speeds and loads. Eventually, this work sets up the test bench and conducts the experiment to verify the simulation result. The simulation result shows maximum induced voltage of 7 V, load power of 6.8 mW. The experimental equivalent induced voltage is 2 V under motor speed of 160 r/min, which is consistent to the simulation result.

Liu, Xiaoxue, Yu, Liangyao, Zheng, Sheng, Chang, Jinghu

A Proposal to Re-architect Automotive OBD Freeze Frame Storage Requirements and the Associated Service-Oriented Freeze Frame Storage Algorithm Design

2018-01-08724/3/2018

Automotive OBD freeze frame storage is mandated by regulations since the creation of OBD-II in 1994. The main purpose is to help service engineers to identify the cause of the associated fault. Although OBD regulations [1] have gone through multiple updates and major changes since 1994, the regulations requirements on freeze frame storage, however, remain almost the same. The flexibility to comply with the mandated requirements allows OEMs to come up with very different designs, and potentially would confuse the service engineers when repairing different powertrains and could compromise the main purpose of helping identify the root cause of faults. In 2015, GM fellows [2], together with SAE J1979 committee members, proposed a set of future requirements on the OBD freeze frame storage with the intention to standardize the requirements by mandating the rules what to store and when to store, the minimum number of frames, and the numbering of the frames. The proposal is better than the current requirements in terms of standardization and modernization, but it has several obvious shortcomings. For example, the minimum of four freeze frame storage will dramatically increase OEM’s costs and could potentially force OEMs to update their powertrain control units to have more storage capacity, and the downward compatibility with the current requirements is questionable. In addition, the prohibition of non-emission related faults in the freeze frames is not a service-friendly solution. Finally, the GM’s proposal gives no priority boarding for misfire or fuel system faults, which does not comply with the ARB CCR 1968.2 requirements. This paper proposes to re-architect the OBD freeze frame storage requirements with low cost to OEMs and downward compatibility to current requirements. In addition, a service-oriented freeze frame storage algorithm design is proposed based on the new requirements. This preliminary work offers OEMs an opportunity to extensively review theirs needs from service and designs and potentially will influence CARB to update the associated freeze frame requirements in the next version.

Guo, Yichao, LU, Wei, Terauchi, Kazumichi

2021-12-29.TEST Information Security Risk Management of Vehicles

2018-01-0015

4/3/2018

The results of this work is allowed to identify a number of cybersecurity threats of the automated security-critical automotive systems, which reduces the efficiency of operation, road safety and system safety. Wired or wireless access of the information networks of the modern vehicles allows to gain control over power unit, chassis, security system components and comfort systems. According to the evaluating criterion of board electronics, the presence of poorly-protected communication channels, the 75% of the researched modern vehicles do not meet the minimum requirements of cybersecurity due to the danger of external blocking of vital systems. The revealed vulnerabilities of the security-critical automotive systems lead to the necessity of developing methods for mechanical and electronic protection of the modern vehicle. The law of normal distribution of the mid-points of the expert evaluation of the cyber-security of a modern vehicle has been determined. Based on the system approach, ranking of the main cybersecurity treats is performed. Electronic body systems of modern vehicles are the most likely to be damaged by intruders, which can lead to the vehicle theft. Using the complex of safety criteria of modern vehicles, the probability and possible consequences of risks in the interception of the control of vehicles are determined. The obtained results can be used at the stages of production and operation of the vehicles with the aim to improve cybersecurity, road safety and system safety as a whole taking into account its life-cycle management.

Klets, Dmytro, Gritsuk, Igor V., Makovetskyi, Andrii, Bulgakov, Nickolay, Podrigalo, Mikhail, Kyrychenko, Ihor, Volska, Olena, Kyzminec, Nikolai

2021-12-29.TEST Security Mechanisms Design for In-Vehicle Network Gateway

2018-01-0018

4/3/2018

In the automotive network architecture, the basic functions of gateway include routing, diagnostic, network management and so on. With the rapid development of connected vehicles, the cybersecurity has become an important topic in the automotive network. A spoof ECU can be used to hack the automotive network. In order to prevent the in-vehicle networks from attacking, the automotive gateway is an important part of the security architecture. A secure gateway should be able to authenticate the connected ECU and control the access to the critical network domain. The data and signals transferred between gateway and ECUs should be protected to against wiretap attacking. The purpose of this paper is to design a secure gateway for in-vehicle networks. In this paper, the designing process of the automotive secure gateway is presented. Based on the threat analysis, security requirements for automotive gateway are defined. Secure communication, key master, and firewall are proposed as the security mechanisms to protect the automotive gateway. Secure communication mechanisms contain the message authentication and data encryption. Key master is a gateway function to distribute and update the keys for the secure communication of connected ECUs. Firewall based on message filter is designed to isolate the untrusted network domain and trusted network domain. The security functions of the automotive gateway are validated in a simulated attacking environment. A microcontroller with HSM is used to implement the secure gateway. Considering the influences of security mechanisms, the network latency is tested and the results have proved the secure gateway is effective and efficient.

Luo, Feng, Hu, Qiang

2021-12-29.TEST Practical Approaches for Detecting DoS Attacks on CAN Network

2018-01-0019

4/3/2018

Some of the recent studies reveal that it is possible to access the in-vehicle networks and inject malicious messages to alter the behavior of the vehicle. Researchers have shown that, it is possible to hack a car’s communication network and remotely take control of brake, steering, power window systems, etc. Hence, it becomes inevitable to implement schemes that detect anomalies and prevent attacks on Controller Area Network (CAN). Our work explores the complete anomaly detection process for CAN. We cover the techniques followed, available tools and challenges at every stage. Beginning with what makes CAN protocol vulnerable, we discuss case studies about attacks on CAN with major focus on Denial of Service (DoS) attack. We analyze the pattern of normal CAN messages obtained from real vehicle, along with patterns of simulated attack data using different methods/tools. The work in this paper presents a statistical data analysis based machine learning algorithm with two approaches “time-based” and “message-based” to detect DoS attack on CAN bus. Comparative analysis of observations and accuracy results are highlighted. The average accuracy obtained for “time-based” approach is 81% while that for “message-based” is 80%.

Kalyanasundaram, Pallavi, Kareti, Venkatesh, Sambranikar, Meghana, SS, Narendra Kumar, Ranadive, Priti

In-Use Compliance Opportunity for Diesel Powertrains

2018-01-08774/3/2018

In-use compliance under LEV III emission standards, GHG, and fuel economy targets beyond 2025 poses a great opportunity for all ICE-based propulsion systems, especially for light-duty diesel powertrain and aftertreatment enhancement. Though diesel powertrains feature excellent fuel-efficiency, robust and complete emissions controls covering any possible operational profiles and duty cycles has always been a challenge. Significant dependency on aftertreatment calibration and configuration has become a norm. With the onset of hybridization and downsizing, small steps of improvement in system stability have shown a promising avenue for enhancing fuel economy while continuously improving emissions robustness. In this paper, a study of current key technologies and associated emissions robustness will be discussed followed by engine and aftertreatment performance target derivations for LEV III compliant powertrains. The core of the discussion will be focused on identifying opportunities in engine and aftertreatment hardware and controls to position the diesel applications appropriately for future in-use compliance. Additionally, the authors will discuss the potential diesel powertrain hardware enhancements that could deliver improved emissions robustness while saving fuel, in real-world operation. Since OBD has become an integral part of in-use compliance, this paper will present novel ways to address the malfunction detection with reduced margin of variance while still delivering robust separation between worst performing acceptable (WPA) and best performing unacceptable (BPU) components. In conclusion, a summary of road maps to position diesel technology for future compliance targets will be presented.

Vakiti, Karthik, Deussen, Joel, Pilger, Claude, Nanjundaswamy, Harsha K., Szailer, Tamas, Franke, Michael, Tomazic, Dean, Thomas, Korfer, Romijn, Marcel, Deppenkemper, Kai, Vagnoni, Giovanni

Lumped Approach for Flow-Through and Wall-Flow Monolithic Reactors Modelling for Real-Time Automotive Applications

2018-01-09544/3/2018

The increasingly restrictive legislation on pollutant emissions is involving new homologation procedures driven to be representative of real driving emissions. This context demands an update of the modelling tools leading to an accurate assessment of the engine and aftertreatment systems performance at the same time as these complex systems are understood as a single element. In addition, virtual engine models must retain the accuracy while reducing the computational effort to get closer to real-time computation. It makes them useful for pre-design and calibration but also potentially applicable to on-board diagnostics purposes. This paper responds to these requirements presenting a lumped modelling approach for the simulation of aftertreatment systems. The basic principles of operation of flow-through and wall-flow monoliths are covered leading the focus to the modelling of gaseous emissions conversion efficiency and particulate matter abatement, i.e. filtration and regeneration processes. The model concept is completed with the solution of pressure drop and heat transfer processes. The lumped approach hypotheses and the solution of the governing equations for every sub-model are detailed. While inertial pressure drop contributions are computed from the characteristic pressure drop coefficient, the porous medium effects in wall-flow monoliths are considered separately. Heat transfer sub-model applies a nodal approach to account for heat exchange and thermal inertia of the monolith substrate and the external canning. In wall-flow monoliths, the filtration and porous media properties are computed as a function of soot load applying a spherical packed bed approach. The soot oxidation mechanism including adsorption reactant phase is presented. Concerning gaseous emissions, the general scheme to solve the chemical species transport in the bulk gas and washcoat regions is also described. In particular, it is finally applied to the modelling of CO and HC abatement in a DOC and DPF brick. The model calibration steps against a set of steady-state in-engine experiments allowing separate certain phenomena are discussed. As a final step, the model performance is assessed against a transient test during which all modelled processes are taking place simultaneously under highly dynamic driving conditions. This test is simulated imposing different integration time-steps to demonstrate the model’s potential for real-time applications.

Payri, Francisco, Arnau, Francisco José, Piqueras, Pedro, Ruiz, María José

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