New Trends and Developments in Automotive System Engineering Part 13 potx

The Car Entertainment System 467 The principles of a good sound output are comparably easy and similar for digital and analog sources. Three key-issues need to be respected: 1. frequency response of speakers matching the human perception response 2. maximally flat phase response leading to a low group delay 3. echo reduced environment The loudspeaker itself has a frequency response, meaning that the loudspeaker is resonant for some audio frequencies, depending on the construction and type of speaker. They can be classified to bass speakers, where only very low end frequencies are audible, mid range speakers and high tone speakers, where only the highest tones are transmitted. Beside these band-limited speakers many vendors offer broadband loudspeakers, which try to transmit a broad range of the audible spectrum. Either the speaker is shifted downwards to the lower end spectrum, neglecting the upper part or wise versa. Due to the mechanical limits in construction of broadband speakers, the frequency response is rippled and not flat, meaning some frequencies are exposed while others are reduced. Figure 15 shows typical 2-way loudspeakers covering the midrange and high tones, while the bass is covered by a single bass speaker, known as subwoofer. The source of very low frequencies cannot be detected by the human ear, therefore only a single bass speaker is sufficient and its position is uncritical. Audio Frequency Response Bass Speaker Midrange Speaker Hightone Speaker Combined Frequency Response Audio Frequency Response Bass Speaker Midrange Speaker Hightone Speaker Combined Frequency Response Fig. 15. Typical frequency responses for a 2-way speaker with bass-reflex booster and 3-way speaker systems The environment in which the speaker operates influences the frequency response of the individual speaker. When the environment is comparably rigid the frequency response shifts to lower frequency band, similar a spring-mass-system where the mass is raised. The volume of the surrounding offers resonances which disturb the frequency responses of the speakers. A good sound system offers a matched frequency response similar the human perception. In order to compensate the deficiency of the speakers and the surroundings, an equalizer corrects this. Equalizing the interior of a vehicle is time consuming and most often a compromise. New Trends and Developments in Automotive System Engineering 468 Another key factor is that frequencies reach the ear at about the same time. This part is often neglected. For a natural sound impression it is obvious that not only the sound representation shall be matched but also the phase representation, known as group delay response. When loudspeakers transmit from a different distance to the listener, transmission delays occur. These delays can be compensated by delay lines in the equalizer. The speaker close to the listener will be delayed, so that sounds from all speakers reach the ear at approximately the same time. When sounds are reflected inside the car more delay is seen. The human hearing system can compensate a certain sound delay, beyond that it becomes recognized as echoes. Echoes are annoying. Taking the interior of a car into account, speakers must be placed cleverly. On the one hand it is necessary that sound reaches the human head directly. On the other hand, echoes must be reduced. Which is quite simple for one person inside the car, the job becomes difficult for all passengers. As this is mostly a compromise between frequency response, group delay response and echoes, some car manufacturers tune the sound to certain positions. For self- driving cars, the focus is the driver and the front passenger, for high-class limousines with backseat passengers, the focus is on rear seats. Some manufacturers offer to change these settings. While regular sound systems provide single broadband speakers, higher class sound systems offer at least dual-way - or better - triple-way speaker systems. Here, a lowpass filter, a bandpass and a highpass filter separates the audio spectrum according to their speaker frequency responses. Adding all frequency responses shall provide a maximally flat response. Driver Zone reflected signal Driver Zone reflected signal Fig. 16. Typical audio loudspeaker distribution inside the car, exhibit direct signals and reflected signals New Trends and Developments in Automotive System Engineering 470 and consoles, the bandwidth is quickly exhausted. In addition, cabling distance for GBit- LANs is also limited. Inside a vehicle, a cabling length of 50 meters or more is not unusual for ring-networks. When the entertainment ring is opened at any point, the whole entertainment program is interrupted. 9. Navigation system It was a long dream of mankind to navigate effortless to any destination. Since end of 1990 th , we have adapted a satellite position determination free of charge from the US military, called Global Positioning System (GPS). Since then, the navigation market raised rapidly. Today we know navigator mobile phones, portable car-retrofit devices and sophisticated in- vehicle map navigation. The Russian GLONASS satellite system has been offered as alternative to the US-system but never reached the awareness limit. In addition, European countries joined to setup their own navigation system GALILEO in opposition to GPS. At the time of this book is written, Galileo satellite system is still years away to come. Hence, we concentrate on GPS in this chapter. For GPS, low orbit satellites fly around the earth in such a way and number that at any point on the surface, minimum 3 satellites are in communication range to the receiver. Each satellite transmits a unique pseudo-noise data stream which is synchronized with an atomic clock. Inside the data stream satellite orbital information are implemented as well as timestamps. The receiver can synchronize to the data streams and calculates the position by time-differences between timestamps and orbital data. With 3 or more such time differences and orbital information, the position on earth can be determined. With the position information and a destination coordinate, a route can be calculated. Today we know a number of vectorized digital maps. Some of them are free of charge, some require a license agreement. The car industry offers a specific roadmap for their fleet. Beside the vector map, a number of additional layers are offered, e.g. petrol stations, fleet repair stations, museums, hotels, restaurants, car parks, etc. known as Point of Interest (POI). These map information are regularly updated. As the vector map base is mostly identical, car manufacturers differ between the qualities of POIs, which becomes a unique selling point. Furthermore, the algorithm to calculate the best route from actual position to destination is one of the important features to distinguish between good and better systems. There are not only shortest route and fastest route available, but in future more in concern becomes the most economic route with a number of parameters, such as fuel consumption for regular engine cars, electric power consumption for electric vehicles and hybrid cars as well as CO 2 -footprint, just to address the most popular. Today we find a number of portable external navigation systems by vendors beyond the car industry. These gadgets are comparably easy to operate and often battery powered. Mobile phones or so called smartphones offer all capabilities needed for guidance by map and voice commands. For these external devices, cabling effort is very limited to DC-power only. An external GPS-antenna is not necessarily required as the reception through regular windscreen glass is sufficient in most of the cases. When sun protective metalized windows are installed in the car, GPS-reception may be disturbed. In this exception an external GPS- antenna is needed. The Car Entertainment System 471 Comparing performance for vehicle installed navigation systems with portable external devices the cost difference is hard to explain to customers as both work equally well. However, the internal system can compensate navigation errors with wheel speed and steering angle even when GPS-reception is not available for some distance, e.g. in tunnels. The upcoming trend in the car industry is to provide interfaces for mobile phones. That means for instance that a smartphone can connect by Bluetooth or USB 2.0 to the vehicular internal GPS-positioning data, which is backed up by wheel speed and steering angles. This enables the phone to be used as hands-free telephone as well as a portable navigation system, having excellent GPS-reception and precise position. The costs and effort for a navigation computer, user interface and map updates are reduced. On top of this, it gives customers the flexibility using any phone model and is future safe. 10. Outlook and future trends From the performance point of view, a lot can be optimized in the entertainment system in the future. Especially broadcasting reception is deemed to be improved. Historically, the tuner was installed in the center console, while the receiving antenna was on the fender. The cable length was comparably short. Modern cars however offer a number of receiving antennas for diversity reception in the rear-window, side-window, bumper and fender for instance. Long cabling ways attenuate RF signals. The wide range of broadcasting standards requires multiple tuners buried in the car. Integration and size reduction is a major playground in R&D departments. Transceivers of modern mobile phones are approximately 30x30 mm² or less and 3 mm thick, offering multi-frequency and multi-standard operation already. With SDR-tuners it will become possible in near future to provide compact multi-standard broadcasting receivers exploiting diversity gain by MIMO concepts. This allows integrating such receivers into - or at least close to - the antennas. Reception performance will improve drastically unless EMC problems occur. Another mega trend of this decade is a permanent internet connection. With UMTS and WLAN it is already possible to connect laptops and mobile phones to the internet while riding in car. In near future, the vehicle itself gets connected to the internet. Upcoming mobile phone standard Long-Term Evolution (LTE) will support this trend. The merge of internet services and vehicular entertainment functionality will provide efficiency and convenience to the passengers. The sheer endless list of new service ideas for the drivers and passengers is overwhelming and becoming unique selling points for car manufactures. They will offer new services to drivers, from intelligent traffic routing, parking aid to firmware updates inside the car. Passengers will be able to stream music and videos as well as communicate while surfing the internet. 11. References Henk, C.M, Hamelink, S.G (2008). FMeXtra – the Principle and its Application, 9th Workshop Digital Broadcasting, Fraunhofer Institute IIS Erlangen, Germany Klawitter, G. (2005). Autoradios, Siebel Verlag, ISBN 3-88180-644-x, Verlag für Technik und Handwerk, Baden-Baden, Germany New Trends and Developments in Automotive System Engineering 472 Koch, N. (2008). Diversity for DAB – Worth the Effort?, 9th Workshop Digital Broadcasting, Fraunhofer Institute IIS Erlangen, Germany Ruoss, M. (2008). The Digitalization of the FM-Band in Europe, 9th Workshop Digital Broadcasting, Fraunhofer Institute IIS Erlangen, Germany 24 Information and Communication Support for Automotive Testing and Validation Mathias Johanson Alkit Communications AB Sweden 1. Introduction The need for automotive testing and validation is growing due to the increasing complexity of electronic control systems in modern vehicles. Since testing and validation is expensive in terms of prototypes and personnel, simply increasing the volume of the testing can be prohibitively costly. Moreover, since product development cycles must be shortened in order to reduce the time-to-market for new products, there is less time available for testing and validation. Consequently, more testing and validation work will have to be performed in less time in future automotive development projects. To some extent this challenge can be met through virtual product development techniques and simulation, but there will still be an increasing need for testing and validation of physical prototypes. This can only be accomplished by improving the efficiency of automotive testing and validation procedures, and the key to realizing this, we will argue in this chapter, is by introducing novel information and communication support tools that fundamentally transform the way automotive testing and validation is conducted. With the explosive proliferation of wireless communication technology over the last few years, new opportunities have emerged for accessing data from vehicles remotely, without requiring physical access to the vehicles. Special purpose wireless communication equipment can be installed in designated test vehicles, acting as gateways to the internal communication buses and to on-board test equipment such as flight recorders. With a fleet of test vehicles thus configured, sophisticated telematics services can be implemented that enable communication of virtually any kind of data to and from any vehicle, providing the bandwidth of the wireless connection is sufficient. This has an enormous potential of making automotive testing and validation more efficient, since much of a test engineer's time is spent finding the right data to analyse. By eliminating the need for the engineer to have physical access to the test vehicle, scarce vehicle prototypes can be made available for multiple simultaneous tests, reducing the overall need for physical prototypes. Moreover, the test vehicles can be accessed by the engineers irrespective of their geographical location, which makes a much broader range of test objects available for tests and frees up time for the engineers in scheduling a prototype for a test. The data resulting from the test can be uploaded from the vehicles to a server from where it can be accessed by any number of interested (and duly authorized) engineers. By having measurement data automatically collected into a central database, as opposed to being stored on the hard drive of each engineer's computer, the opportunities for reuse of data is greatly New Trends and Developments in Automotive System Engineering 474 improved. One can also imagine (semi-)automated analysis mechanisms being executed on the data being uploaded to a server, assisting the engineer in interpreting the data. A specific kind of data of paramount importance in automotive testing and validation is diagnostic data generated by designated diagnostic functions built into the vehicle's Electronic Control Units (ECU). By collecting and analysing Diagnostic Trouble Codes (DTC) for test vehicles, faults can be detected and corrected before the vehicle goes into production. Statistical analysis of DTCs is also important in order to find correlations between faults and to prioritise different development efforts. With the advent of wireless telematics services, diagnostic data can be collected more systematically in different development phases. This means that there will be fewer faults in production vehicles, preventing costly recalls. Since many faults that are detected in the testing and validation phases of automotive development are software related, having wireless access to fleets of test vehicles means that the software in the ECUs can be remotely updated with a bug-fixed software release over the wireless connection. Reprogramming an ECU in the traditional way is a time consuming procedure that requires test equipment to be connected physically to each vehicle. Through remote software download, many vehicles can be updated simultaneously without requiring physical access. Automotive testing facilities are commonly located in remote rural areas, due to the need for extreme climate conditions and privacy. A side-effect of this is that a significant part of the budget for automotive testing expeditions is the travel costs for the engineers. By utilizing tools to remotely access data, complemented with tools for distributed collaborative work between the test site and the automotive company's development sites, engineers can take part in testing expeditions remotely, without having to travel. The tremendous impact on automotive testing and validation processes that will result from large scale introduction of the technology and concepts described here has the potential of affecting the whole automotive development process. Referring to the established V-model of product development that is often used to elucidate automotive development processes, the testing and validation phases are at the same level as the design and simulation phases (see Fig. 1). This captures the fact that there is a considerable interplay of creative and Fig. 1. V-model of automotive product development Information and Communication Support for Automotive Testing and Validation 475 analytical processes between these stages of the automotive development (Weber, 2009). Hence, it is easy to see that when the testing and validation phases are changed, this will heavily influence the design and simulation stages. Specifically, with an improved testing and validation process, whereby performance measurements and diagnostic data can be efficiently collected, analysed and fed back into the design process, the opportunities for component and system re-design is greatly facilitated. Moreover, validation of simulation models by measurement data improves the possibilities of more extensive simulations and virtual prototyping. Since the innovations in automotive engineering made possible by telematics services and related information and communication systems go way beyond the testing and validation stages, automotive management processes will have to be adapted to maximize the benefits. From an innovation management standpoint, Lenfle and Midler (2003) argue that the introduction of telematics services constitutes a definitive turning point for the automotive industry, which will require the adoption of management tools specifically adapted to the collective learning process involved in this field of innovation. In the remainder of this chapter we will explore the opportunities of improving automotive testing and validation by means of sophisticated information and communication support tools. Specifically, the following classes of applications will be studied: • automotive metrology and data collection, • remote vehicle diagnostics, • remote software download, • distributed collaborative automotive engineering. The focus is primarily on consumer grade vehicle development (i.e. passenger cars), although most of the technology and applications are equally relevant (and in some cases even more relevant) for trucks, buses, construction equipment, and other special purpose vehicles. Furthermore, the focus is on the later stages of the automotive development process, where testing and validation of physical prototypes and pre-series vehicles is of vital importance. The rest of this chapter is organized as follows: Section 2 gives a short introduction to automotive testing and validation; section 3 contains an overview of vehicular communication infrastructure; section 4 discusses information and communication support for automotive metrology and data collection; section 5 deals with automotive diagnostics and prognostics applications, in particular concerning telematics services and statistical analysis of diagnostic data; section 6 treats telematics services for remote ECU software updates; section 7 discusses distributed collaborative automotive engineering, and section 8 provides conclusions and a future outlook. 2. Automotive testing and validation The development of complex products in the exceedingly competitive automotive industry is a demanding undertaking that requires a very sophisticated quality assurance process. Quality assurance in the automotive industry is complicated by the high level of integration of components from many different suppliers and the fact that many of the subsystems are safety-critical. Specifically, for the embedded electronic systems that constitute a substantial part of the total development cost, the design process is based on a close cooperation New Trends and Developments in Automotive System Engineering 476 between car manufacturers and suppliers, whereby the carmakers provide the specifications of the subsystems to the suppliers, who design and deliver the systems. The resulting components are integrated into the vehicle platform by the carmaker, which performs the necessary testing and validation (Navet & Simonot-Lion, 2009). The automotive testing and validation processes have undergone dramatic developments following the exponential increase in the number and complexity of electronic control systems in vehicles. With as much as 23 percent of the total manufacturing cost of a high- end vehicle being related to electronics, and an estimate that more than 80 percent of all automotive innovation stem from electronics (Leen & Heffernan, 2002), the importance of testing and validation methods for electronic components, including software, becomes evident. This situation has spurred the development of on-board diagnostics functions being designed in parallel with the electronics components. Increasingly sophisticated external test equipment connected to the vehicles' internal communication buses has also been developed and the ability to measure physical properties through built-in sensors has been greatly improved. This has led to the current situation where automotive testing and validation is largely a practice of data capture (metrology), communication and processing. Sophisticated data analysis software has been developed to meet the need for high volume data processing, which includes filtering, transformations, visualization and various statistical methods. 2.1 Validation and verification In many situations a distinction is made between verification and validation. Verification refers to a process to determine whether a system or service complies with its specification, whereas validation is a quality assurance process for determining if a system or service fulfils its requirements and lives up to customer expectations. In this chapter we will use the term validation informally in both meanings, leaving to the reader to discern the subtle distinction from the context. 3. Vehicular communication infrastructure The tremendous development of digital communication technologies over the last few decades has fundamentally transformed automotive testing and validation, making it possible to access and distribute vehicle data efficiently and reliably. We will briefly outline the state of the art in communication infrastructure for automotive applications. 3.1 In-vehicle communication networks Modern automobiles typically contain between 20 and 50 ECUs, controlling different subsystems of the vehicle. The ECUs are interconnected by an in-vehicle communication bus. In many cases there is more than one such bus, interconnecting different subsets of ECUs. The original motivation for in-vehicle networks was to reduce weight by replacing discrete wiring, but the additional benefit of improved means of communication between electronic subsystems can now be seen as one of the major facilitators of technological innovation in automotive engineering. The most common in-vehicle bus technology currently in use is the Controller Area Network (CAN) developed by Bosch in the mid 1980s. CAN is a broadcast serial bus [...]... diagnostics data and other vehicle data almost ubiquitously This has a tremendous impact on the way automotive testing and validation is conducted Instead of devoting much of their time to hunting down prototype vehicles for the purpose of reading out diagnostic data or 490 New Trends and Developments in Automotive System Engineering reconfiguring flight recorders, the engineers can focus on designing test... increasingly important tasks in automotive engineering From a testing and validation perspective, tracking down and documenting ECU software bugs have become major issues When a software bug has been found and fixed, the new version of the software needs to be installed, followed by new testing to verify that the problem is solved and that no new problems have been introduced The cycle of finding software related... important for preservation and reuse Knowing where a measurement was conducted can also be valuable contextual information in the analysis of the data 482 New Trends and Developments in Automotive System Engineering 5 Remote vehicle diagnostics and prognostics Collection and analysis of diagnostic data from electronic control units in vehicles is of vital importance in the automotive industry, both from... while they are not in a traffic situation (for example, while on private residential property) 496 New Trends and Developments in Automotive System Engineering 2.1.3 Asia Gandhi & Trivedi (2007) give a good overview of statistics in developing countries in their introduction During 2001, there were 80,000 fatalities on Indian roads, which grew in the last decade by 5% per year (Singh, 2005), with 60%–80%... been well integrated, resulting in unnecessary duplication of effort in developing different diagnostics applications, each with its own infrastructure and software components This leads to inefficient use of resources and high costs for developing and maintaining the diagnostics applications Luo et al (2007) further stress the Information and Communication Support for Automotive Testing and Validation... sophisticated software tools for remote interactions and data sharing between the engineers Information and Communication Support for Automotive Testing and Validation 489 Traditionally, tools for collaborative engineering and design have focused on supporting distributed group meetings using synchronous communication tools, like videoconferencing and application sharing Sophisticated collaboration studios... safety conscious, and insurance companies and regulators begin to recognise the positive impact such systems can have on accident rates Concurrently, vision systems are becoming increasingly common in road vehicles due to advances in technology, as discussed in the previous section Some vehicles currently come equipped with vision systems for displaying blind zone and as parking and reversing aids However,... 494 New Trends and Developments in Automotive System Engineering actualisation, and scene processing for active machine vision-based safety assessment Visual display applications require the display of the vehicle’s environment in such a manner that is both intuitive and useful to the driver of the vehicle Scene processing applications require a video stream that is suitable for automated processing... logger' are sometimes used synonymously 480 New Trends and Developments in Automotive System Engineering Fig 2 Measurement data capture and analysis cycle 4.1 Wireless communication in automotive metrology To improve the efficiency of fault tracing in automotive development, a key concern is to reduce the time of the data capture and analysis cycle, shown in Fig 2 With the advent of more or less ubiquitous... Developments in Automotive System Engineering view to enable the driver of a motor vehicle to detect areas behind the motor vehicle to reduce death and injury resulting from backing incidents, particularly incidents involving small children and disabled persons” and that the expanded field-of-view “may be met by the provision of additional mirrors, sensors, cameras, or other technology to expand the driver’s . and the surroundings, an equalizer corrects this. Equalizing the interior of a vehicle is time consuming and most often a compromise. New Trends and Developments in Automotive System Engineering. distribution inside the car, exhibit direct signals and reflected signals New Trends and Developments in Automotive System Engineering 470 and consoles, the bandwidth is quickly exhausted. In addition,. prototyping. Since the innovations in automotive engineering made possible by telematics services and related information and communication systems go way beyond the testing and validation stages, automotive