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Testing real-time vehicular systems challenges the tester to design test cases for concurrent and sequential input events, emulating unexpected user and usage profiles. The vehicle response should be robust to unexpected user actions. Sequence Covering Arrays (SCA) offer an approach which can emulate such unexpected user actions by generating an optimized set of test vectors which cover all possible t-way sequences of events. The objective of this research was to find an efficient nonfunctional sequence testing (NFST) strategy for testing the robustness of real-time automotive embedded systems measured by their ability to recover (prove-out test) after applying sequences of user and usage patterns generated by combinatorial test algorithms, considered as “noisy” inputs. The method was validated with a case study of an automotive embedded system tested at Hardware-In-the-Loop (HIL) level. The random sequences were able to alter the system functionality observed at the prove-out test.

To improve the effectiveness and efficiency of decision making during vehicle development programmes, new interactive NVH simulation tools have been introduced. For their optimum use during the target setting of NVH attributes new methodologies need to be established. A valuable step in achieving this is to further understand opinion forming processes during on-road appraisals. To achieve this however new approaches to capture the events of an appraisal are needed. This paper reports on the first steps taken towards developing these new approaches and demonstrates how attitudes towards vehicle sound quality and driver behavior can vary depending on the personality traits of the assessor and their role within the OEM. This insight will provide a benchmark to compare how expert assessors and customers make decisions.

Increased torque values passing from engine to transmission have, increasingly become a problem regarding shaft misalignment. Engineers are restricted with regard to applying ISO standards when investigating bearing life cycles as they tend only to cover normal [radial thrust] load conditions. Depending on the application, the need has arisen for numerical models to determine reduction in normal life cycles due to abnormal running conditions. The Simulia Finite Element package Abaqus v6.7 provides trends in the deformations, contact pressures and their respective distribution. It was found the most efficient profile, with regards to a uniform contact pressure, under both radial and misaligned conditions is the toroidal profile.

The objective of the research discussed in this paper is to propose a methodology for comparing candidate electrical architectures on a cost basis at the very beginning of the architecture design process. To achieve this objective, historical data concerning the cost of a wiring harness for a driver’s door electrical system is analysed along with information on an electrical architecture for the door system of a small four door passenger car. The study is focused around a driver’s door electrical system based on LIN and hardwired integration. However, it is concluded that the results are applicable to other types of automotive electrical architectures.

For a typical communications C-language software stack, its size in terms of ROM and RAM will be dependent upon the network properties such as number of nodes, schedules, messages and signals. A lot of this information is part of a more detailed design and during architecture selection only signal and nodal information will be available. Messages and schedule information will be part of a much more detailed part of the design process. The objective of the study described in this paper is to ascertain whether ROM and RAM requirements can be estimated from only node and signal information only as this is the information that tends to be available at the very beginning of the electrical architecture design process. Historical data from a LIN design and its associated communications stack is statistically analysed and used to develop a methodology for ROM and RAM requirement estimation.

An automotive side door latch release mechanism has been modelled for the locking and unlocking vehicle functionality in Dymola. The performance of the developed door lock model is evaluated against an existing model of a similar door locking/unlocking system in Stateflow. The model performance is also compared with measurements from a real vehicle door latch. The model is converted into a Simulink model and built for a real-time environment such as the dSPACE target with a fixed step size solver. It is shown that a step size as small as 1 ms can be used for real-time simulation without task overrunning in the real-time target. The model is also benchmarked on a multiprocessor setup as multiprocessor simulators are common in system-level networked Electronic Controller Unit (ECU) testing facilities for implementing high fidelity closed loop models of integrated ECUs and actuators.

The objective of the Project is to develop a low cost lead-acid battery solution for hybrid electric vehicles based on a novel, individual, spirally wound valve-regulated lead-acid 2V cell optimized for this application. This cell will be used as a building block for the development of a complete battery pack that is managed at the cell level. Following bench testing, this battery pack will be thoroughly evaluated by substituting it for the Nickel/Metal Hydride pack in a Honda Insight A paper given at the Future Car Congress in June 2002 covered the first half of the 3-year project and described work carried out in the following areas: Development of cell and battery testing facilities. The design and development of the prototype double-ended cell. The development of the battery pack specification and pack design. The development of the battery management system. It also gave details of the test results obtained on the demonstration vehicle with its original NiMH battery.

The Controller Area Network (CAN) has seen enormous success in automotive body and powertrain control systems, as well as industrial automation systems using higher layer protocols such as CANopen and DeviceNet. Now, the CAN standard ISO11898 is being extended to Time Triggered CAN (TTCAN) to address the safety critical needs of first generation drive-by-wire systems. However, their successful development depends upon the availability of silicon and software support, and appropriate development & analysis tools. Warwick Control Technologies and the University of Warwick are tasked with prototyping a TTCAN analyser within the European Union Media+ project Silicon Systems for Automotive Electronics (SSAE) consortium, and with funding from the British Department of Trade and Industry (DTI). This paper briefly outlines the current status of both CAN & TTCAN technology and describes the requirements of a TTCAN analyser over that of a traditional CAN analyser.

A low cost CAN bus load transducer, requiring only a few low cost components, has been developed. Traditionally, to ascertain CAN bus loading, an algorithm based upon a number of assumptions executed on a microcontroller is required. This has many disadvantages that include being potentially costly, inaccurate and can take up a significant amount of processing, especially under higher bus load situations causing a higher number of interrupts. However, the CAN bus load transducer developed, is connected to the CAN bus and outputs a varying signal proportional to bus loading. A microcontroller can then simply be used to read the bus load signal and covert it into percentage bus loading as often as is required. The method is inexpensive, accurate and provides a continuous signal for CAN bus loading measurement that does not become expensive in terms of processing under higher bus load conditions. In this paper, the application of the CAN bus load transducer technology is explored.

The Controller Area Network (CAN) has seen enormous success in automotive body and powertrain control systems. However, there is a change in emphasis arising in the industry in which CAN is seen as too powerful and expensive for simple digital body control applications, but not robust or fast enough for more safety critical applications such as the envisaged Drive-by-Wire systems of future passenger cars. The emerging protocols Local Interconnect Network (LIN), the Time Triggered Protocols (TTP/A, TTP/C), Time Triggered CAN (TTC) and Byteflight are examined in terms of their application and likelihood for future success. The paper is concluded with comments concerning a newly announced protocol known as FlexRay.

The popularity of CAN (Controller Area Network) in the production vehicles is well established. As a result, CAN has been developed for use in many non-automotive applications. This gave rise to the development of an open higher layer CAN protocol known as DeviceNet. With the popularity of DeviceNet for Automation Systems, this technology has drastically decreased in cost. Although DeviceNet is quite complex to develop, it easier to implement than SAE J1939 due to the large number of commercial off-the-shelf product that is available. Also, there are many configuration and diagnostic tools available by the same means. There are more than 300 vendors of DeviceNet product. Researchers at the University of Warwick have built a vehicle demonstrator using CAN/DeviceNet modules. This paper will illustrate the ease of vehicle system integration utilising this popular technology.

This paper outlines a method of producing optically perfect transparent glass fiber pre-pregs. The technique uses a wetting resin in a sandwich construction with glass fibers; the construction process induces complete wetting of the fibers such that they are not visible in the resin. The transparent pre-pregs have subsequently been laid into a mould and back-injected with polycarbonate. Results show that components produced via this method exhibit flexural rigidity three times greater than unreinforced equivalent polycarbonate mouldings.

The objective of the Project is to develop an optimized lead-acid battery solution for HEVs based on a novel, individual, spirally wound valve-regulated lead-acid 2V cell optimized for HEV use and low variability. This cell will be used as a building block for the development of a complete battery pack that is managed at the cell level. Following bench testing, this battery pack will be thoroughly evaluated by substituting it for the NiMH pack in a Honda Insight. The paper covers the first half of the 3-year project and will describe work carried out in the following areas: Development of cell and battery testing facilities and identification of mechanisms causing cell lifetime scatter. The design and development of the prototype double-ended cell. The development of the battery pack specification and pack design. The development of the battery management system. The paper will also give details of the test results obtained on the demonstration vehicle with its original NiMH battery.

Sound quality targets for new vehicles are currently specified by jury evaluation techniques based upon listening studies in a sound laboratory. However, jury testing is costly, time consuming and at present there are no methods to include customer expectations or brand requirements. This paper describes a neural computing approach that is being developed to generate knowledge and tools to enable objective measures of a product's sound to be converted into a prediction of the subjective impression of potential customers without carrying out the traditional jury evaluation tests.

Hardware-in-the-loop (HIL) simulations have long been used to test electronic control units (ECUs) and software in car manufacturers. It provides an effective platform to the rapid development process of the ECU control algorithms and accommodates the added complexity of the plant under control. Accurate Model based HIL simulation (AMHIL) is considered as a most efficient and cost effective way for exploration of new designs and development of new products, particularly in calibration and parameterization of vehicle stability controllers. The work presented in the paper is to develop a mathematical model of a windscreen wiper system for the purpose of conducting HIL vehicle test and eventually to replace the real component with the model for cost cutting and improved test efficiency. The model is developed based on the electro-mechanical engineering principles.

Robustness is particularly important in complex systems of systems due to emergent behaviour. This paper presents two novel, techniques developed as part of a framework for design for robustness of complex automotive electronic systems, but in principle could be applied to a broad range of distributed electronic systems. The overall framework is described to give the context of use for the techniques. The first technique is a “robustness case” which is a structured argument for the robustness of a system analogous to a safety case. The second is a model based approach to early robustness verification of complex systems. The approaches are demonstrated by their application to the system initialisation of the propulsion control system of a hybrid electric vehicle. The hybrid system initialisation process is discussed in terms of the key objectives and the technical implementation, illustrating the level of complexity underlying a simple high level requirement.

Complexity of electronics and embedded software systems in automobiles has been increasing over the years. This necessitates the need for an effective and exhaustive development and validation process in order to deliver fault free vehicles at reduced time to market. Model-based Product Engineering (MBPE) is a new process for development and validation of embedded control software. The process is generic and defines the engineering activities to plan and assess the progress and quality of the software developed for automotive applications. The MBPE process is comprised of six levels (one design level and five verification and validation levels) ranging from the vehicle requirements phase to the start of production. The process describes the work products to be delivered during the course of product development and also aligns the delivery plan to overall vehicle development milestones.

Increasing automation in the automotive systems has re-focused the industry’s attention on verification and validation methods and especially on the development of test scenarios. The complex nature of Advanced Driver Assistance Systems (ADASs) and Automated Driving (AD) systems warrant the adoption of new and innovative means of evaluating and establishing the safety of such systems. In this paper, the authors discuss the results from a semi-structured interview study, which involved interviewing ADAS and AD experts across the industry supply chain. Eighteen experts (each with over 10 years’ of experience in testing and development of automotive systems) from different countries were interviewed on two themes: test methods and test scenarios. Each of the themes had three guiding questions which had some follow-up questions. The interviews were transcribed and a thematic analysis via coding was conducted on the transcripts.

A Rover car equipped with a Controller Area Network (CAN) system was tested for radio frequency susceptibilities in the Electromagnetic Compatibility (EMC) chamber at Rover Gaydon Test Centre. The system consisted of four electronic control units linked together using a serial network (CAN) to share signal information. The car was configured in turn with two different types of twisted pair wire and a flat pair for the CAN data bus. Each type of wire was tested in the chamber at a range of frequencies and with various antenna positions. The CAN data was collected and stored on a commercially available personal computer (PC) based network analyzer for later analysis to determine bus latency under EMC error conditions.

For high Reynolds number flows, the fine structure turbulence is universal in the inertial subrange according to the Kolmogorov local isotropy theory; while for low-to-moderate Reynolds number flows, the turbulence tends to display a common structure for a particular type of shear flows from the Townsend structural similarity. The power laws for the turbulent flows reflect the similarity in the turbulence fine structure. The paper discusses the relationship between drop breakup and turbulence fine structure. A predictive formula for drop breakup in the turbulent flow is suggested based on the energy balance between turbulence separating kinetic energy (i.e. turbulence structure function) and surface tension. The model has been validated on a number of empirical relations for drop breakup in different turbulent flows. It is known that the drop size distribution in shear flows can be approximately expressed by a lognormal distribution.