Search Results

This paper discusses a streamlined approach for characterizing the heat flows from the combustion chamber to the engine coolant, engine oil circuit and the ambient. The approach in this paper uses a built-in flow and heat transfer solver in the CAD model of the engine to derive heat transfer coefficients for the coolant-block interface, oil-block interface and the block-ambient interface. These coefficients take into account the changing boundary conditions of flow rate, temperatures, and combustion heat to help characterize the complex thermal interactions between each of these sub-systems during the warm-up process. This information is fed into a larger system model of the engine to get a more accurate prediction of the engine warm-up and the effect of various fuel economy improvement strategies being evaluated. One of the key benefits shared in this paper is the practicality of the process that can be replicated on every production vehicle simulation model.

Automotive electronic systems are becoming safety related causing a need for more systematic and stringent approaches for demonstrating the functional safety. The safety case consists of an argumentation, supported by evidence, of why the system is safe to operate in a given context. It is dependent on referencing and aggregating information which is part of the EAST-ADL2, an architecture description language for automotive embedded systems. This paper explores the possibilities of integrating the safety case metamodel with the EAST-ADL2, enabling safety case development in close connection to the system model. This is done by including a safety case object in EAST-ADL2, and defining the external and internal relations.

The trend in automotive systems is towards an increasing complexity, where much of safety-critical functionality is implemented in software. The emerging safety automotive standard ISO-26262, will require safety cases where are clearly argued that a system is safe in all aspects, and where showing a timely behaviour is one necessary condition. Based on industrial experiences and actual research from as well automotive as aerospace domains, this paper shows how the safety requirements from ISO-26262 with respect to timing can be met even in a complex situation, such as enabled by AUTOSAR.

With the change of luminaires from incandescent bulbs to Light Emitting Diodes (LED), we all know that the concept of thermal management for this application is now redundant and new ways of thinking need to be established. While incandescent bulbs mostly radiate (~83%) and dissipate (~12%) heat loss and do not face thermal challenges related to the light source, LEDs mostly transfer their heat loss (~60-85%) by conduction and are sensitive to the thermal management. Therefore the efficiency of a 100W incandescent bulb is ~5% while the efficiency of LEDs is ~15-40%. The main thermal challenges with LEDs are to maintain a high color stability and life expectancy. LEDs in the automotive industry need to have lifelong durability. With LEDs being not only more efficient, but also valuable in terms of higher visibility and therefore higher safety, the Economic Commission for Europe (ECE) set the Day-time running lamp (DRL) as mandatory from 2011 for all new models of cars.

With several automotive OEMs recently embracing AUTOSAR as a mandate for electronic modules throughout the vehicle, and with the established legacy around implementations of Infotainment, Instrument Cluster and Telematics systems, we see some questions and uncertainty around the best way forward. This is further complicated by the desire of many OEMs to enable the use of mobile applications and other aspects of the mobile operating systems available from Google, Apple and others, and the desire to leverage content residing on connected mobile devices. And it seems inevitable that more powerful silicon devices will enable a reduction in the number of electronic control modules in the vehicle architecture, through module consolidation.

Software and electronic circuits are commonly used with mechanical components today. In the past, the design of functionally sufficient and robust mechanical components was always completed by experienced mechanical engineers. This is changing, however. The requirements of additional functionality and reduced price have led to the introduction of mechatronics - mechanical parts augmented with electronic hardware controlled by software. Designing and verifying such a system is a challenge that requires a change in methodology as two very different engineering disciplines collide. This paper illustrates a simulation-based design methodology for software controlled, electro-mechanical components using an autonomous mobile robot as an example. VHDL-AMS, the Analog-Mixed-Signal extension (IEEE 1076.1) of the digital hardware description language VDHL, was used as the main modeling language.

This paper describes the joint development of a data model exchange interface based on STEP AP212 to support the flow of electrical data through the design process - specifically between the Mentor Graphics CHS (ECAD) system and the UGS NX3 (MCAD) system. The reasons for selecting AP212 in preference to the AP210 and KBL data exchange protocols are discussed. The scope of the interface is discussed, and examples are presented of the translation of real-world electrical objects into the AP212 data model. The definition of the exchange file format is described, with examples, and the reasoning behind its design is discussed.