Next Generation Automotive Embedded Computing Requirements and Reference Platform Selection Issues. N. Abid Ali Khan Research Engineer – Embedded Systems Lab Technology, Information, Forecasting & Assessment Council, Department of Science & Technology Cent er Of Relevance and Excellence (TIFAC – CORE), Advanced Computing & Information Processing SASTRA University, Thanjavur – 613402, India.
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[email protected]; Ph No: (+091)-099-650-71698 ABSTRACT
1. Introduction
Electronic Control Unit (ECU) designs in automobiles, offering various in-vehicle services to the customer has been paradigm over the last couple of decades. This paper addresses the issues to be concentrated by automotive IT service providers specifying the next generation automotive customer needs with advances in technologies. The paper points the processor variants impact with the portability of Real-Time Operating System (RTOS) on the ECU sustainability in terms of value added features with better operability and quick integration of new added values. Later in this paper, we focus on changes in body electronics with impact and necessity to integrate smaller sub-systems of existing vehicle infrastructure to form a distributed network and have an intelligent communication network topology. We will address to some of the future changes that are likely to take place in Material Sciences through Nano fibers and Fuel Cell Hydrogen powered super car needs. The issues to consider in rapid growing features in the unstable consumer electronics market in wireless gadgets such as Cellular phones or PDA technologies will be under the future Telematics trends of automobiles. The paper concludes with the recommendations of key points that are needed to be concentrated with the ongoing Research in Vast areas of technology with results obtained in Intelligent Vehicle Computing platform.
Categories and Subject Descriptors Artificial Intelligence – Automotive ECU Designs General Terms Original Equipment Manufacturer (OEM), Telematics, Wireless Networking, Embedded Systems, 3G, 4G and Sensor Networks. Keywords Embedded Processor, RTOS, ECU, GPS, GSM, CAN, MOST, Flexrey, USB-OTG, RISC, FPGA, W-CDMA, 4G, TCP/IP.
IT companies offering Electronic Control Unit (ECU) designs and services to the OEM specifications are suffering with some of the key technological aspects and market issues. This paper addresses these factors and gives the possible key points to note while selecting an automotive software reference design platform. Initially we will focus on the version variant processor selection impact in analyzing the complexity of the design, cost and performance issues with necessity of Real Time Operating Systems (RTOS) and selecting a right embedded microcontroller with open source issues. The advances in body electronics with upcoming wireless sensor network standards are driving more complexity in taking decisions to opt for right software reference automotive platform. The buses with higher data rates connected to the sensor circuits of the mechanical parts in a vehicle forces the design to be hardreal time and with an increasing demand of infotainment and multimedia, the portability of the real-time operating system and its performance are the key factors which we will look in detail in this paper. One vehicle talk to the other and all to a central computing station offering services, which imposes much burden on computing power and query handling at the central computing station. The server services to OEM must be platform independent and should service whatever processor based dash-board electronics is embedded into the vehicle. The services such as real-time vehicle tracking through GPS, traffic monitoring and alerting systems stuffed with real-time guided assistance are some of the key requirements that need high data throughput to offer.
2. Advances in Processor Architectures This is one of the key issue when we always look for embedded microcontroller performance in terms of clock speed, availability of memory, set of automotive communication bus interfaces such as CAN, MOST or Flexrey, power consumption, embedded USB, USB-OTG offering multimedia and high data storage services including new software updates. Automotive electronic vehicle infrastructure initially has started with small low-cost 8/16 bitmicrocontrollers running a small dedicated application. Today’s 1
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automobiles require high data processing capability and all most all dash board electronics are stuffed with 32-bit RISC processors or FPGA based designs. The revolutionary designs with in-built ASIC IP cores and in built memories with peripherals are in progress in VLSI era. The internal competitions in semiconductor industry vendors are delivering the new wide variety of processor cores for automotive designs with reliable processor cores such as ARM, Power PC, TI’s DSP and Sharc processors with various versions. Typically, selecting an embedded processor for automotive reference design involves the following issues. ? The Clock Speed. ? In Built Program and Data Memory. ? Set of Embedded Automotive Interfaces. ? Supported IDE and Debuggers. ? On-chip integrated peripherals. ? Feasibility of porting Real-Time Operating System. ? Power consumption of the embedded processor. ? Integrated on-chip Cache memory. ? External Memory and DMA access. ? Supporting RISC architecture features. ? In-built MAC for TCP/IP. Selecting the RISC based pipe-line architectures are mostly recommended in today’s automotive requirement as it offers better performance with good power savings at less clock rates. On the other hand IDEs are available from VLSI firm’s as well to work on automotive versatile FPGAs even the actual hardware is not available. In most of the industry proven automotive cores, provision to scale the processor clock to offer low-speed baud-rate for in-built peripheral devices is also a major aspect to notice. The advantages such as the portability of application developed for older version of RISC can be directly ported even in the latest version of the vendor specific RISC core without any more changes or integrating with the new features to the already developed design makes RISC cores at top than to go for 8/16 bit traditional microcontrollers. This will not only minimize the development time of the project but also lead to innovative services to offer. For example, ARM926EJ-S for instance, is a powerful ARM version based embedded core with advantages as mentioned. The user friendly compilers allow the software developers to design and build the custom software though the hardware is not available. Supporting the Java based programming environment eases the basic connectivity and processing of the central computing station either through SQL/MySQL queries by providing Java virtual Machine enabled cross compilers.
3. RTOS Needs & Open source Apart from the services that need to address from a central computing station to process the queries, the embedded processor needs to meet the hard real-time timing constraints for the unpredictable inputs from the mechanical nodes through sensors. This forces the seamless selection of a reference board which not only meet the requirements as of processing the central computing queries end with computing power is concerned; but also to handle the unpredictable interrupts through porting the real-time
operating system kernels much more efficiently with less foot print, future up gradable as well as meeting the critical dead lines. The selection of open source RT kernels optimizes the design cost; still the same platform has to address the query management and session with the central computing station, which is basic need in for an automotive service provider. Figure – 1 highlights the different RTOS issues that need to be considered for a cost efficient design with better performance. Vxworks®, Greenhill®, Nucleolus®, Integrity®, QNX® are some of the proven hard-real time kernels that are portable to any standard embedded RISC microcontrollers with automotive peripherals built in. OSEK, RT-Linux etc., are some of the royalty-free RT kernels that OEM’s are currently using for next generation automotive market needs.
Fig – 1: RTOS selection Criteria. The set of in-built automotive protocol stacks like integrated Flexray, CAN, CANOpen, AUTOSAR, MOST API function calls availability for wired controllers and integration of Zigbee or IEEE802.15.4, IrDA stacks for wireless automotive needs makes the selection of RT-kernels a big puzzle to project managers! While requirements on memory grow, for example, several trends are forcing powertrain software producers to add increasingly complex software algorithms that require more processor speed with examples like stringent emission regulations, advanced cruise control, better fuel efficiency, and anti-knock algorithms, the add-on service complexity also tend to increase. Optimized real-time kernels for the modern processors with set of standard automotive cores or for FPGA based versatile core-modules must meet the requirements with consistently producing the highest performance code in the automotive industry. Also easily customizable user friendly IDE compilers, ICE, logic analyzers and software debuggers are prerequisites for automotive current market trends.
4. OEM Body Electronics Future Trends In the very near future, further system services will be added to the vehicle. Although it would be possible to use the existing network in-vehicle infrastructure, for many of the new functions to embed, it would not be practical. The additional performance 2
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and complexities which are associated with the higher classes of networks are more expensive to implement. It is also more prudent from a safety standpoint to keep non-safety-critical information apart from the networks which support safety critical systems. Already some luxury vehicles have networks which resemble the networking infrastructure as shown in Figure-2. The vehicle control and body electronics control networks have been integrated with certain specialist networks. The Braking, Steering and Suspension controllers are becoming more complex and interactive in order to support full vehicle stability management systems. These systems are linked on a high-speed bus, which supports fault-tolerance.
hydraulic back-up is available (as in the case of a ‘by -wire’ system), the system must continue to function in the event of a fault occurring. The unsuitability of the existing communications protocols is mainly due to the fact that they are ‘event-triggered’. A precise moment in time when a message will be received is not specified. A communications protocol can only be predictable if worst case transmission time and jitter are known at the time of the design and meet the requirements of the application. The maximum jitter depends on the longest message that it is possible to transmit. Real-time control applications are very sensitive to jitter and it is an important parameter for developing real-time distributed automotive embedded systems as in Figure-2 in future. Hybrid cars, Fuel Cell stack based Hydrogen powered super cars are the key OEM future needs probably not for the next generation; but, the generation after that. Nano Fibers will also find the significant role to play to decrease the cost and obviously driving more Technology aspects and parameters that an IT service provider must keep an eye offering user and environment friendly solutions to take part in automobiles. Research in these areas is already progressive in many western countries.
5. Automotive Telematics Trends
Fig-2: Automotive Future Body Electronics. There is a redundant bus which operates in parallel so that in the event of a fault on one bus, another exists. The Airbag system is composed of many different airbags including side airbags, rear seat airbags, etc. These are all linked on a custom network which is very robust. Finally, a very high speed ‘Intelligent Transportation Systems’ (ITS) network has been added which would use a transmission medium such as fiber optics to transfer audio and video information. Each bus system caters for the characteristics of the system and balances performance with the cost of implementing each network. Although the electronics industry is by no means short of serial communications protocols, until now there has been surprisingly little progress in developing a low cost network which provides fault tolerant communication. Fault tolerant systems are set to become a growth area in the not too distant future, particularly in the automotive world, as brake-by-wire and steer-by-wire systems are set to become a reality in the next few years. Such systems must be ‘fail-operational’ as they are deemed safety critical; if the system develops a fault, it could have life-endangering consequences. ‘By-wire’ systems transfer electrical signals down a wire instead of using a medium such as hydraulic fluid to transfer muscular energy. A conventional Antilock Braking System (ABS) is considered ‘fail-silent’; if a fault in the electronic control system is detected, the control system is switched off, leaving the manual hydraulic back-up still operational. If no such
The majority of OEM vendors agree that from the end-user prospective, the key reason behind the rapidly changing specifications are due to advances in wireless cellular phones, offering better features at low-cost. This imposes an extra burden and forms one of the key specification requirement in choosing the right software development platform and support for the better reliable and sustainable product.
Fig–3: Wireless Development Life Cycle. The primary Telematics market need in automobiles of automatically synchronizing the owner’s cell phone as soon as the person operates the vehicle, tuning the cellular phone always with a central computing station, fetching the services such as vehicle 3
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tracking, speed control, guided assistance, traffic alerts, radio, navigation, e-mail, ease of calls through voice to text and text to speech translation has to be done with a single reference design, which is a technology dependant. Figure-3A shows the statistics of how the technology in mobile consumer products has been evolved and is likely to continue in future as well. Figure-3B shows the research done already and progressive statistics in future wireless technologies and is on the way to hit the market by the key technology providers. The second issue that most bother is the amount of data throughput needed at the centralized server to handle the queries from different OEM clients. These queries must be processed in real-time by fetching the information from the existing databases with certain level of computing and providing the valuable information to the driver in the vehicle. The architectures such as Internet-scale Resource-Intensive Sensor services (IRIS), which is intended to develop a scalable software infrastructure that will enable users with Internet access to data mine the wide world of webcams is presently a wide area of research. IRIS will facilitate the deployment of webcam services that leverage both real-time and historical video feeds from any number of webcams, from other data sources, and from other types of sensor data. Each sensor is locally attached to a computer that is capable of resource-intensive processing such as image recognition. A key design goal is to facilitate dynamic reconfigurability in the sensing mobile agent networks, which a vehicle may provide to the centralized server and react from the server to talk directly with the mechanical nodes of the vehicle. Therefore the reference wireless technology selection is extremely tricky. GSM, for instance, which is the globally accepted wireless cellular technology, is on the verge. The reference designs of current automotive key Telematics providers are developing and offering the new services over GSM frequency band. However, the world class DSP giants on the other hand have already started research in the area of W-CDMA, 4G – the next generation wireless technology, which may tremendously offer good services with covering a large band in consumer cellular devices soon by 2012. So, OEMs have to address these key aspects of rapidly changing cellular market needs as well!
Figure–4: Vehicle details tuned with the cellular systems at server The OEM services are provided through ASP based web-pages keeping in mind of the rapidly changing mobile phones or cellular systems or PDA consumer electronics market, as discussed. The adaptive digital map as shown in the figure-5 will provide the shortest path to any requested destination. For this prototype the University premises has been taken into consideration and implemented the query hand shaking. Through proper channel and following the Government norms to access the complete database of the state is currently in progress. This initial proposed prototype will provide the conceptual proof of vehicle monitoring over a TCP/IP link via GPRS enabled Cellular phone which in turn talks with the embedded dash board electronics.
6. Ongoing Research and Results: The ongoing research in Telematics at our Center of Excellence is mainly focused on Telematics automotive Infotainment system design. The administrative user privileges are maintained at the server to access the vehicles database with high-end computing throughput workstation, typically operating at a 17.4TeraFlops of speed, where all the active vehicles will be sensed and tracked through GPS fixed in the vehicles as shown in Figure-4. The query processing from the central computing station to any OEM client is done by SQL. Once the owner of the vehicle is properly being authenticated, the GPRS cellular phone will be automatically tune and synchronized with the embedded ECU in the vehicle and the vehicle will be monitored through out the journey and updates the same for each time slice as in Figure-4.
Figure–5: Indicating shortest path on a digital map to Driver. The server will then monitor and updates the vehicular information automatically and offer services. This query processing architecture will serve the other related requested services by vehicles irrespective of OEM vendor’s consumer electronic product market variations.
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7. CONCLUSION This paper addresses the issues of next generation automotive embedded control unit requirements in depth, identifying the key potentials of the existing technologies Vs the customer demands. We have seen the key aspects of processor selection with the platform selection issues for reference designs to build. We have also seen the real-time kernels need in ECU complex software integrations with the future body electronics enhancements that are driving the market needs. The issues of development of Intelligent Transportation System (ITS) were addressed with the integration of advances in body electronics developments to keep in tune with the Telematics ongoing research while selecting the reference design as a platform for any OEM need. The future Telematics trends with the expected changes in consumer cellular systems through the research all over the globe will certainly impact the way the IT services are offering in today’s automobiles. The on-going research in DOTAUTO project for platform independent OEM’s dash-board electronics with the landed results were projected at the end of the paper. Overall, we focused on how the technology changes in body electronics, Telematics, embedding Nano Technology in material science with Hydrogen powered fuel cell based super cars will define the next generation IT market requirements from automobile industry; and The Lions of automotive industries and Academics just might do the trick!
8. ACKNOWLEDGMENTS This work was funded by TIFAC-CORE in Advanced Computing and Information Processing, Department of Science and Technology, Govt. of India. I would like dedicate this white paper to Prof Ushadevi K, Dean – School of Computing & Coordinator TIFAC-CORE who is the key motivator to me. I would like to thank Prof R Sethuraman, Vice-Chancellor, SASTRA University, for providing scope to work and encouraging me towards
Research in all aspects. I would like to thank Mr. Venkatesh Chandrashekaran, Head, Center of Automotive Excellence, Satyam Computers Ltd., Mr. Sai Mohan, Assistant Manager – marketing, Satyam Computers Ltd., and Satyam’s DOTAUTO teammates for their valuable suggestions and most importantly to DOTAUTO project teammates of TIFAC-CORE, SASTRA University for their encouragement and contribution in this work.
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