Number Of Electronic Control Units Research Articles

Automotive decentralized diagnosis based on CAN real-time analysis

Abstract Nowadays, modern automotive systems include a great number of Electronic Control Units (ECUs). These ECUs provide many sophisticated systems such as engine control, antilock braking systems, etc. This fact has increased the automotive embedded networks complexity. Another important issue in this field is the necessity to define a suitable diagnosis strategy to prevent faults propagation. The integration of diagnosis functions into the automotive embedded systems contributes to overload the communication protocols. In this context, solutions for checking latencies entailed by extra-data traffic are urgently needed. Throughout this paper, a novel approach for the automotive diagnosis design, which is based on the Controller Area Network (CAN) analysis, is detailed. The principal contribution of this work consists in developing a decentralized fault diagnosis and studying its data traffic effect on messages deadlines. Our novel method, “CAN real-time analysis based on decentralized fault diagnosis”, is a step ahead to a reliable early phase automotive design. As a proof of concept, the proposed approach is applied on a model of an advanced anti-crash system. The proposed design methodology presents several advantages. It optimizes the schedulability of tasks and facilitates the design validation. Moreover, a realistic hardware-in-the-loop simulation is carried out to validate our work.

Improving Worst-Case Delay Analysis for Traffic of Additional Stream Reservation Class in Ethernet-AVB Network.

With the increase in the number of Electronic Control Units (ECUs) and future requirements for vehicle functions, two SR (Stream Reservation) traffic classes may not be sufficient to ensure fulfilment of constraints for multiple traffic types with individual timing requirements transmitted in the Ethernet-AVB (Audio Video Bridging) networks. The goal of this paper is to determine the worst-case delay for an additional SR traffic class under the CBS (Credit-Based Shaper) algorithm. Delay evaluation is based on the impact analysis of CBS on different priority flows, particularly depending on when the credits of both SR class A and B drain from the worst-case perspective. More specifically, both the impact of CBS and the evolution trends of credit on different priority class flows are first analyzed from the worst-case perspective. Then, for an additional SR class, two types of worst-case delay models are established with the CBS configuration suggestions. Finally, an approach to calculate the worst-case queuing delay is proposed. Moreover, the worst-case end-to-end delay is determined by the network calculus approach and simulation. Numerical results show that the delay bounds of our models are tighter than those of other models, which is beneficial to the development of Ethernet-AVB for in-vehicle networking.

Software Platform for Heterogeneous In-Vehicle Environments

Modern technologies lead to more sophisticated hardware, while software is becoming more complex. These trends are widely present in consumer electronics and do not bypass automotive electronics either. There is an evident recent growth in in-vehicle infotainment, telematics, advanced driver assistance systems (ADASs) and cluster development. The number of electronic control units (ECUs) in vehicle constantly grows. Since typical vehicle ECU is providing one function per vehicle, it becomes harder for manufacturers to manage these ECUs due to diverse nature of the system, hence a rising demand for ECU consolidation exists. With the availability of sophisticated hardware, powerful system-on-chips (SoCs) can be used for multiple functions inside a vehicle. The transition toward less ECUs is an ongoing process, in which software needs to be aligned first and then transferred to the same SoC. This paper presents the software platform for heterogeneous immersive in-vehicle environments, providing a step in software consolidation, by allowing same abstractions for diverse applications executing on various hardware platforms. It proposes a framework for the scalable development of ADAS from consumer level to different automotive safety levels, provides unified access toward algorithm building blocks, multi-sensor real-time environment and easy integration of algorithms, thus enabling shorter development time.

Hardware Trojan Enabled Denial of Service Attack on CAN Bus

The trend of technological advances in the vehicle industry illustrates that future cars would have added functionalities with smart features, better connectivity and autonomous behaviour. These naturally involve a higher number of Electronic Control Units (ECUs) being connected using existing conventional in-vehicle network protocols such as Controller Area Network (CAN). In this context, security of systems is now becoming a major concern while industry’s primary interest in the manufacturing of cars is reliability and safety. It is now in daily news that smart cars are being hacked due to weaknesses in their embedded electronics that provides ways of hardware attacks [1] [2].Hardware Trojan (HT) is the threat that has been recently recognised as one of the primary sources of backdoor access that enables hackers to attack systems. As trouble, HT remains silent until a rare function/event triggers it for activation. This paper contributes to the challenge of demonstration of disruption in CAN buses raised from hidden Hardware Trojan. In this regard, it is presented how just a small size Hardware Trojan disrupts the CAN bus communication without an adversary having physical access to the bus. The attack is neither detectable via frame analysis, nor can be prevented via network segmentation; additionally, a rare triggering mechanism activates HT to process untraceable faults.

Experience Report: Towards Extending an OSEK-Compliant RTOS with Mixed Criticality Support

Background: With an increase of the number of features in a vehicle, the computational requirements also increase, and vehicles may contain up to 100 Electronic Control Units (ECUs) to accommodate these requirements. For cost-e ectiveness reasons, amongst others, it is considered desirable to limit the growth of, or preferably reduce, the number of ECUs. To that end, mixed criticality is a promising approach that received a lot of attention in the literature, primarily from a theoretical perspective. Aim: In this paper, we address mixed criticality from a practical perspective. Our prime goal is to extend an OSEK-compliant real-time operating system (RTOS) with mixed criticality support, enabling such support in the automotive domain. In addition, we aim at a system (i) supporting more than two criticality levels; (ii) with minimal overhead upon an increase of the so-called criticality level indicator of the system; (iii) requiring no changes to an underlying operating system; and (iv) featuring further extensions, such as hierarchical scheduling and multi-core. Method: We used the so-called adaptive mixed criticality (AMC) scheme as a starting point for mixed criticality. We extended that scheme from two to more than two criticality levels (satisfying (i)) and complemented it with specified behavior for criticality level changes. We baptized our extended scheme AMC*. Rather than selecting a specific OSEK-compliant RTOS, we selected ExSched, an operating system independent external CPU scheduler framework for real-time systems, which requires no modifications to the original operating system source code (satisfying (iii)) and features further extensions (satisfying (iv)). Results: Although we managed to build a functional prototype of our system, our experience with ExSched made us decide to rebuild the system with a specific OSEK-compliant RTOS, being µC/OS-II. We also briefly report upon our experience with AMC* and suggest directions for improvements. Conclusions: Compared to extending ExSched with AMC*, extending µC/OS-II turned out to be straightforward. Although we now have a basic system operational and available for experimentation, enhancements of the AMC*-scheme are considered desirable before exploitation in a vehicle.

Intravehicular Energy-Harvesting Wireless Networks: Reducing Costs and Emissions

Vehicles have mutated from mechanical systems into cyberphysical systems featuring a large number of electronic control units (ECUs), sensors, and actuators. The wiring harnesses used for the transmission of data and power delivery for these components may have up to 4,000 parts, weigh as much as 40 kg, and contain up to 4 km of wiring. The amount of wiring is expected to grow as vehicles evolve and begin to include enhanced active safety features and, eventually, self-driving capabilities and diversified sensing resources. Consequently, the ability to eliminate wires in vehicles is a compelling value proposition; it decreases part, manufacturing, and maintenance costs and improves fuel efficiency and, therefore, greenhouse gas emissions. Furthermore, it may spur innovation by providing an open architecture to accommodate new components, offering the potential for growth in automotive applications-possibly similar to the computer and phone industry over the past decade.

Integrated Course projects in Automotive Electronics and RTOS

It is seen that the number of Electronic Control Units (ECUs) in the automotive has grown significantly in recent years. In today's luxury cars, up to 2500 signals are exchanged by up to 70-80 ECUs. The number communication channels implement required realize such systems is about n2, here n is the number of ECUs in the automobile. This complexity requires the use of communication networks between them and to manage the functionality of these ECUs the Real-Time Operating Systems (RTOS) is used. This real world scenario has motivated us to give the hands on experience to students by introducing integrated course projects, which includes the use of Real-Time Operating Systems (RTOS) in automotive embedded systems. This activity also involves creating an industry like environment for execution of the project. Deployment of more advanced control strategies and integration of sub modules were the major technical outcomes of the activity. For executing this activity, the problem statement given was divided into sub-problems and each sub problem is converted to sub module/ECU depicting the industry scenario. The concepts of automotive embedded systems were used during sub module development and during integration the concepts of RTOS were used. The activity provided the method and tool to facilitate the integration of different electronic subsystems coming from various suppliers. The activity created the feel of real world industry environment amongst the students and enabled to achieve various technical and professional outcomes of ABET. The processes of achieving these outcomes are discussed.

Improved Automotive CAN Protocol Based on Payload Reduction and Selective Bit Stuffing

In this research paper, the implementation strategies of automotive controller area network protocol are investigated and the short messaging scheme with selective bit stuffing method to improve the effective utilization of its bandwidth has been proposed. There would be a sharp decrease in the performance of traditional CAN protocol because of considerable increase in the number of ECUs (Electronic Control Units) and infotainment gadgets connected in the vehicle architecture. The demand for safety, emission, diagnostics and comfort norms has steeply increased the number of messages in the 250 Kbps CAN network as the computational power of ECUs has gone up. To overcome this problem, the short CAN method has been proposed and the work is benchmarked with SAEJ1939 Heavy commercial vehicle CAN standard. The Matlab Simulink based short CAN has been modeled and the performance of the proposed system has evaluated using virtual instrument cluster. Experimental results have shown that compared to the traditional CAN, the proposed method has reduced the worst case response time of CAN extended frame from 160 μ sec to 144 μ sec. Selective bit stuffing technique has reduced the impact of bit stuffing over the payload and improved the utilization factor for the CAN bus without affecting the CAN message ID properties. The proposed algorithm has been modeled and simulated using CAN Matlab model Simulink and it has been verified using virtual CAN tool and real time CAN bus hardware.

ISO 26262 표준 기반의 소프트웨어 검증을 위한 소프트웨어 결함 주입 기법

As the number of ECUs (Electronic control units) are increasing, reliability and functional stability of a software in an ECU is getting more important. Therefore the application of functional safety standards ISO 26262 is making the software more reliable. Software fault injection test (SFIT) is required as a verification technique for the application of ISO 26262. In case of applying SFIT, an artificial error is injected to inspect the vulnerability of the system which is not easily detected during normal operation. In this paper, the basic concept of SFIT will be examined and the application of SIFT based on ISO26262 will be described.

Design of a dynamic LED system controlling multi-LEDs based on AURIX multi-core processor

Recently, dynamic LED lighting systems become more important in automobile industry. Also, one of most important things in the automobile embedded system is to reduce the number of electronic control unit in vehicles. In this paper, we propose a novel design of a dynamic LED lighting system using Infineon AURIX processor which has a multi-core architecture to overcome above issue. For the implementation of a dynamic LED system, in this design, three LEDs are controlled using three cores independently. Detailed implementation of the demonstration system using color sequences for LED and a LED device is presented herein and the experimental result shows that the proposed method works well.

In-car power line communications: Advanced transmission techniques

The increasing number of electronic control units (ECUs) inside a vehicle implies the need to develop and deploy on board robust, low latency and low complex telecommunication systems. In this respect, power line communications (PLC) is an attractive solution. The benefits provided by the introduction of power line communications in the in-car environment are multiple and they are related to the possibility of exploiting the existing and capillary wiring infrastructure to simplify the design of the in-vehicle data network (IVN) and, more importantly, to save weight and cost of the wiring harness. In this paper, we deal with the analysis of the performance achievable by applying innovative advanced modulation techniques to in-car measured power line channels, i.e., multicarrier (MC) and impulsive ultra wideband (I-UWB) modulation. We show that for low speed command and control applications, I-UWB is suitable since it requires lower power and lower computational efforts w.r.t. MC systems. Furthermore, we study the design of the optimal transmitted pulse to further improve the performance of I-UWB.

COST-EFFECTIVE WIRE-HARNESS MODEL BY USING POLYMER OPTICAL FIBER

In the past decade automotive industries faced the exponential increase of in-vehicle electronic devic es. The hydraulic systems are replacing with sophisticate e lectronic systems. Market demands for exploiting ne w in-vehicle technologies such as multimedia systems, internet access, GPS, Mobile communication, intern al private network; engine, body and power train intel ligent control and monitoring systems are increasin g daily. These new needs make the wire-harness as physical pathway for power and data more complex. The amount of different data types’ transmission in veh icle networking requires higher bandwidth and subsequently applying expensive and advanced equipment. Also more functions and facilities lead to rai se the number of Electronic Control Units (ECU). The high cost of manufacturing and implementing all mentioned equipment and systems only can be justifi ed to luxury vehicle’s high prices. This study pres ents a conceptual model of in-vehicle networking which would lead to apply considerable portion of these advanced systems in non-luxury vehicles. In this co ntext, Polymer Optical Fibers (POF) exploited to achieve high speed bandwidth and cost-effective sol ution to transfer huge amount of data and one ECU to control and manage body/cabin electronic devices . Regarding to technical specification of POFs and using visible light as data carrier, they can meet all new needs of implementing modern expected technologies for non-luxury cars at inexpensive sol ution. In addition, POFs are easy-to-use, reliable and flexible in compare with silica base optical fi bers. This study suggests three red, blue and green lights for transferring video/audio, communication data network such as internet/vehicle internal network and body/cabin command lines respectively. Moreover, this concept model claims for reducing wire-harness with integration of command l ines into multiplexed POF line. By command lines integration also it is possible to merge seve ral power lines into one load calculated and shared power wire along the vehicle. After that, this conc eptual model can decrease the amount of different connectors and control switches in car electronic s ystems. At last, this solution can effects on all s teps of vehicle design, manufacturing and assembly proce ss, especially in electronic section.

FlexRay 네트워크 시스템을 위한 FIBEX 자동 생성 알고리즘에 관한 연구

As vehicles become more intelligent for safety and convenience of drivers, in-vehicle networking systems such as controller are network (CAN) have been widely used due to increasing number of electronic control unit (ECU). Recently, FlexRay was developed to replace CAN protocol in chassis networking systems, to remedy the shortage of transmission capacity and unsatisfactory real-time transmission delay of conventional CAN. However, it is difficult for vehicle network designers to calculate platform configuration registers (PCR) and determine a base cycle or slot length of FlexRay. To assist vehicle network designers for designing FlexRay cluster, this paper presents automatic field bus exchange format (FIBEX) generation algorithm from CANdb information, which is de-facto standard database format for CAN. To design this program, structures of FIBEX, CANdb and relationship among PCR variables are analyzed.

Reconfigurable Computing in Next-Generation Automotive Networks

Modern vehicles incorporate a significant amount of computation, which has led to an increase in the number of computational nodes and the need for faster in-vehicle networks. Functions range from noncritical control of electric windows, through critical drive-by-wire systems, to entertainment applications; as more systems are automated, this variety and number will continue to increase. Accommodating the varying computational and communication requirements of such a diverse range of functions requires flexible networks and embedded computing devices. As the number of electronic control units (ECUs) increases, power and efficiency become more important, more so in next-generation electric vehicles. Moreover, predictability and isolation of safety-critical functions are nontrivial challenges when aggregating multiple functions onto fewer nodes. Reconfigurable computing can play a key role in addressing these challenges, providing both static and dynamic flexibility, with high computational capabilities, at lower power consumption. Reconfigurable hardware also provides resources and methods to address deterministic requirements, reliability and isolation of aggregated functions. This letter presents some initial research on the place of reconfigurable computing in future vehicles.

New Concept for Reducing Wire-Harness and Implementing Advanced Facilities for Non-Luxury Vehicles via Application of POF

In the past decade automotive industries being faced the exponential increase of in-vehicle electronic devices. The hydraulic systems are replaced with sophisticated electronic systems. Market demands for exploiting new in-vehicle technologies such as multimedia systems, internet access, GPS, Mobile communication, internal private network; engine, body and power train intelligent control and monitoring systems are increasing daily. These new needs make the wire-harness as physical pathway for power and data more complex. The amount of different data types transmission in vehicle networking requires higher bandwidth and subsequently applying expensive and advanced equipment. Furthermore functions and facilities lead to raise the number of electronic control units (ECU). The high cost of manufacturing and implementing the previous equipment and systems only can be justified to luxury vehicles high prices. This paper presents a conceptual model of in-vehicle networking which would lead to the appliance of considerable portion of these advanced systems in non-luxury vehicles. In this context, polymer optical fibers (POF) exploited to achieve high speed bandwidth and cost-effective solution to transfer huge amount of data and one ECU to control and manage body/cabin electronic devices. This paper suggests three red, blue and green lights for transferring video/audio, communication data network such as internet/vehicle internal network and body/cabin command lines respectively. Moreover, this concept model claims for reducing wire-harness with integration of command lines into multiplexed POF line.

Expanding transmission capacity of can systems using dual communication channels with kalman prediction

The controller area network (CAN) protocol is widely used for in-vehicle network (IVN) systems, and many automotive companies also use the CAN in chassis network systems. However, the increasing number of electronic control units (ECUs) dictated by the need for more intelligent and fuel-efficient functions requires an IVN system with a greater transmission capacity and less network delay. Automotive companies have tried several approaches such as segmenting CAN systems and developing time-triggered protocols. This paper presents a practical method for increasing the transmission capacity and reducing the network delay in CAN systems using dual communication channels with a traffic-balancing algorithm based on Kalman prediction to forecast the traffic on each channel and allocate frames to the one that is most appropriate. An experimental testbed using commercial microcontrollers with two or more CAN protocol controllers was used to demonstrate the feasibility of the Kalman traffic-balancing algorithm. Experimental results show that the traffic-balancing CAN system with Kalman prediction reduced the transmission delay of all priority messages compared to that of a simple method, such as a channel-switching CAN, without sacrificing the performance for high-priority messages.

Design Optimization of Vehicle Control Networks

The advancement of electronic technology has made significant contributions to the safety and convenience of modern vehicles. New intelligent functionalities of vehicles have been implemented in a number of electronic control units (ECUs) that are connected to each in vehicle control networks (VCNs). However, with the rapid increase in the number of ECUs, VCNs currently face several challenges, e.g., design complexity, space constraints, system reliability, and interdependency. Considering these factors, the complexity of the VCN design problem exponentially increases, which means that the problem cannot be solved within a reasonable time using conventional optimization techniques. In this paper, we report a new methodology for the optimal design of VCNs. An analytical model was derived to examine the fundamental characteristics of the VCN design problem. Compared with the case of a conventional data network, which typically considers temporal scheduling over a fixed physical topology, the VCN design problem should also consider spatial constraints, e.g., volume, position, and weight. Moreover, the spatial constraints change during the solving procedure. Such temporal and spatial joint optimization problems with varying constraints incur extremely high computational complexity. To tackle the high complexity, this paper proposes a fast solution based on a repeated-matching method, which reduces the problem complexity from <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">O</i> ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">NNN</i> ) to <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">O</i> ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">NN</i> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> ). By applying our methodology to a number of different real-world VCN design scenarios, this proposal can produce a 1% near-optimal design within a significantly reduced time.

Design of Homogeneous MultiCore based Vehicular Embedded Controller

Increasing use of Electronic gadget in vehicular system need researchers‟ attention to provide optimize solution for the system; in various aspects like power consumption, size, cost, complexity etc. There are many economic and technical arguments for the reduction of the number of Electronic Control Units (ECUs). One can be number of nearby applications of homogeneous or heterogeneous nature can be controlled by one ECU. The use of multi-core technology gives facility to put multiple cores depends on the applications in to single die with their peripherals. The paper presents design of multi-core embedded controller for vehicular system. Two Leon processor cores connected with AMBA shared bus with memory and peripherals. Some vehicular applications are modeled on the designed system. The modeling of dual core embedded system and application are presented in the paper with their simulation results

Design and simulation of automotive communication networks: the challenges

In the last few years the amount of electronics inside cars has increased significantly. Current vehicles have implemented highly distributed electronic systems. The high number of Electronic Control Units (ECUs) and the high amount of data which must be exchanged require high bandwidth and reliable communication systems. Flexray is the communication protocol developed to fulfill these requirements. Due to its higher data rate and consequent bit length reduction, Flexray has more restrictive specifications than its precursor. One of the main goals of the communication network designers is on ensuring sufficient signal integrity at the analog bus. Behavioral simulations can be a useful tool for forecasting design problems and for supporting architecture decision. In this context, the paper explains the main reasons for analyzing the Electrical Physical Layer (EPL), lists the advantages of using behavioral simulations and provides a detailed overview of the challenges related to network design and verification. Moreover, it illustrates the impact of different aspects by way of dedicated use cases, such as topology decision and aging effects, on the signal integrity and therefore on communication quality and system robustness.

매틀랩/시뮬링크 기반 플렉스레이 네트워크 시스템의 구현 및 검증

As increasing the number of Electronic Control Units in a vehicle, the proportion for reliability and stability of the software is going increasingly. Accordingly, the traditional CAN network has occurred the situation that the requirement of developing vehicle software is not sufficient. To solve these problems, the FlexRay network which is ensured the high bandwidth and real-time is generated. However it is difficult to implement FlexRay based application software because of complex protocol than traditional CAN network. Accordingly the system for analysis and verification of network state is needed. Also vehicle vendor develops application software using Matlab/Simulink in order to increase productivity. But this development method is hard to solve the network problem of node to node. Therefore this paper implements Matlab/Simulink based FlexRay network system and verifies it through comparing with existing embedded system.