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Journal Article

Markov Chain-based Reliability Analysis for Automotive Fail-Operational Systems

2017-03-28
2017-01-0052
A main challenge when developing next generation architectures for automated driving ECUs is to guarantee reliable functionality. Today’s fail safe systems will not be able to handle electronic failures due to the missing “mechanical” fallback or the intervening driver. This means, fail operational based on redundancy is an essential part for improving the functional safety, especially in safety-related braking and steering systems. The 2-out-of-2 Diagnostic Fail Safe (2oo2DFS) system is a promising approach to realize redundancy with manageable costs. In this contribution, we evaluate the reliability of this concept for a symmetric and an asymmetric Electronic Power Steering (EPS) ECU. For this, we use a Markov chain model as a typical method for analyzing the reliability and Mean Time To Failure (MTTF) in majority redundancy approaches. As a basis, the failure rates of the used components and the microcontroller are considered.
Technical Paper

Non-standard CAN Network Topologies Verification at High Speed Transmission Rate using VHDL-AMS

2010-04-12
2010-01-0688
This paper considers the verification of non-standard CAN network topologies of the physical layer at high speed transmission rate (500.0Kbps and 1.0Mbps). These network topologies including single star, multiple stars, and hybrid topologies (multiple stars in combination with linear bus or with ring topology) are simulated by using behavior modeling language (VHDL-AMS) in comparison to measurement. Throughout the verification process, CAN transceiver behavioral model together with other CAN physical layer simulation components have been proved to be very accurate. The modeling of measurement environment of the CAN network is discussed, showing how to get the measurement and simulation results well matched. This demonstrates that the simulation solution is reliable, which is highly desired and very important for the verification requirement in CAN physical layer design.
Technical Paper

Diagnostic and Control Systems for Automotive Power Electronics

2001-03-05
2001-01-0075
The recent improvements in automotive electronics have had a tremendous impact on safety, comfort and emissions. But the continuous increase of the volume of electronic equipment in cars (representing more than 25% of purchasing volume) as well as the increasing system complexity represent a new challenge to quality, post-sales customer support and maintenance. Identifying a fault in a complex network of ECUs, where the different functions are getting more and more intricate, is not an easy task. It can be shown that with the levels of reliability common in 1980, an upper-range automobile of today could never function fault-free. On-Board-Diagnostics (OBD) concepts are emerging to assist the maintenance personnel in localizing the source of a problem with high accuracy, reducing the vehicle repair time, repair costs and costs of warranty claims.
Technical Paper

μAFS High Resolution ADB/AFS Solution

2016-04-05
2016-01-1410
A cooperation of several research partners supported by the German Federal Ministry of Research and Education proposes a new active matrix LED light source. A multi pixel flip chip LED array is directly mounted to an active driver IC. A total of 1024 pixel can be individually addressed through a serial data bus. Several of these units are integrated in a prototype headlamp to enable advanced light distribution patterns in an evaluation vehicle.
Technical Paper

Extended Qualification of Power MOSFET to Fulfill Today's Requirements of Automotive Applications

2006-04-03
2006-01-0592
This paper focuses on the requirements of electronic systems in automotive applications in terms of reliability and quality. As one of the most common devices in such applications for switching electronic loads, the power MOSFET, is investigated in detail. Today's qualification procedure for discrete devices according to AEC Q101 [1] will be explained and how this correlates to the stress of the device in the application. It will be pointed out what additional tests for “extended qualification” should be made to deal with critical failure modes reducing overly conservative safety margins and preventing excessive costs on the component side. The tests will be explained and the results presented.
Technical Paper

Design Process Changes Enabling Rapid Development

2004-10-18
2004-21-0085
This paper will address the electronic development in the wireless industry and compare it to the electronic development in the automotive industry. The wireless industry is characterized by rapid, dramatic high tech changes with a less than two-year cycle time and an equivalent life cycle. The automotive electronics industry is working toward reducing the typical 2 to 3 year development cycle down 1 to 2 years but with a life cycle of 10 years or more. In addition to realizing the electronic development benefits seen in the wireless industry, the automotive industry places significantly more emphasis on the quality and reliability aspects of their designs as many of them are targeted toward, or interface with, safety critical applications. One of the lessons learned from the wireless industry is the development process; where the hardware selection process can be accomplished in a virtual environment in conjunction with concurrent software development.
Technical Paper

Microsecond Bus (μSB): The New Open-Market Peripheral Serial Communication Standard

2005-04-11
2005-01-0057
For the past approximately 20 years, the Serial Peripheral Interface (SPI) has been the established standard for serial communication between a host or central microprocessor and peripheral devices. This standard has been used extensively in control modules covering the entire spectrum of automotive applications, as well as non-automotive applications. As the complexity of engine control modules grows, with the number of vehicle actuators being controlled and monitored increasing, the number of loads the central microprocessor has to manage is growing accordingly. These loads are typically controlled using discrete and pulse-width modulated (PWM) outputs from the microcontroller when real-time operation is essential or via SPI when real-time response is not critical. The increase of already high pin-count on microcontrollers, the associated routing effort and demand for connected power stages is a concern of cost and reliability for future ECU designs.
Technical Paper

Smart Power Supply Concept for 32-Bit Microcontroller Applications

2000-03-06
2000-01-1242
The increasing complexity of automotive electronic systems can only be managed by a higher integration of the modules and a high reliability of the individual electronic devices. That means, the number of electronic components on board will decrease and their complexity will increase. This paper describes how to meet the requirements for the power supply of a 32-bit microcontroller based system in an automotive environment.
Technical Paper

High Pincount Packages Under Automotive Conditions

2000-03-06
2000-01-0459
New generation microcontrollers for automotive applications require a huge number of I/Os, dealing with various sensor and actuator signals derived from the external world. In case of the first TriCore™ based 32-Bit microcontroller this leads to approximately 270 I/Os for signal processing. Adding the power supply lines and thermal balls, the overall number of required interconnects grows far over 300. To outperform standard microcontroller packages, e.g. QFPs, the limitations in terms of package size and maximum number of interconnects have to be improved. Main goal is to adapt the component quality to the high level reliability standard, which is the basis of an implementation into automotive parts. Current tests with a P-BGA standard package show interesting results for the board level reliability, when design and test parameters are changed only slightly.
Technical Paper

LED Modules for Matrix and Pixel Light Solutions - On the Way to New Features in Headlight Systems

2014-04-01
2014-01-0432
Glare-free high beams are a consistent enhancement of adaptive headlight systems for vehicles with advanced driver assist systems. A prerequisite for these are camera-based systems with the ability to recognize and classify objects such as vehicles in front or oncoming vehicles when driving at night. These objects can then be dynamically masked out of the high beam of the specially designed headlights. Since we are talking about moving objects, it is essential for the high beam to be continuously and dynamically adapted. This paper describes a modular LED matrix system for dynamically adjusting a glare-free and continuously active high beam. The main focus was on the modularity of the system and the optimization of the thermal properties of an LED matrix in order to ensure that operation was reliable under the harsh environmental conditions inside a headlight. Specific control electronics and different interconnection methods were examined.
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