Part two of three of the series “Turnkey Vehicle Development From a Single Source”.You find the first part of the series here.
Within the last decade, FEV has become an engineering service provider capable of covering the entire service spectrum of vehicle development. Three articles take a closer look at vehicle modules, body shell, interior/exterior, light and sight and chassis modules. Vehicle properties, such as NVH, driving dynamics, passive and active safety, and fatigue strength are considered. Virtual and real-life testing are the development tools here. The activities are accompanied by various control tasks such as benchmarking with subsequent target setting, test and prototype planning, weight management and homologation.
FEV assumes responsibility for the complete scope of turnkey vehicle development, as well as for the development of individual modules and for the selective design and calculation scope of individual components. The fact that the development competence for powertrain, transmission and vehicle comes from a single source makes FEV an ideal development partner – also for electrified vehicles. FEV offers particular expertise in the conversion of conventionally powered vehicles into electric vehicles. The ideal results here can be achieved only through the closely integrated and parallel development of powertrain and vehicle. Some turnkey vehicle development tasks will be introduced in the following:
Light an sight
In automotive development, the field of “light and sight” assumes a central role at the interface of design, comfort and safety. Thanks to its years of experience, FEV offers its customers comprehensive support, with advance development projects, right through to series management. Its particular specialization is in the calculation, design and production-friendly construction of headlights, taillights, and side and interior lights. Be it laser light developments for headlights or transparent OLEDs for taillight applications, FEV is a leader in setting new standards. The company has a broad range of expertise and skills in the field of micro-optical components, such as MLA technology and REALEYES 3D technology. With the bionic approach of micro-lens array technology (MLA; Figure 1) for the first time enabling the implementation of LED projectors with completely new properties: the compact size of an LED projector with sharp projection images on arbitrary geometries with the smallest possible angle of incidence.
>> FEV IS A LEADER IN SETTING NEW STANDARDS
By using REALEYES 3D technology, it is possible to display 3D graphics and logos “in front” of a screen, without 3D glasses or further tools being necessary. This highly innovative technology is currently being further developed for the automotive sector and offers great potential in terms of driver information and safety, among other things.
Test and validation
Vehicle development is shaped by strict customer and market requirements. In addition to innovation, safety, and economic efficiency, reliability is an important prerequisite that has a direct impact on the follow-up costs. Country-specific legislation lays out the basic requirements of a complete vehicle. These are defined as the basis for each development project and thereby define the development process. An important step here is the validation that proves these requirements have been met.
The term validation covers the topics fatigue strength, function, and performance. For this, FEV has comprehensive test options, as well as extensive knowledge of the necessary target parameters. The fatigue strength of the powertrain, chassis components and cellular vehicle structure is validated during the endurance test drive. In a validation test program for the planned range of applications of a vehicle, the accumulated routes are divided proportionally into various sections of the journey, representing urban traffic, highway journeys and driving on country roads, and include roads with poor surfaces and mountain roads. Hot and cold climate testing is also included. Each section poses a different challenge for the powertrain and the overall vehicle.
>> GLOBALLY ACTIVE VEHICLE MANUFACTURERS HAVE TO MEET VARIOUS REQUIREMENTS AROUND THE WORLD
However, these test scenarios do not yet take into account the special features of ADAS/AD vehicles. New scenarios are defined that test the control units on various levels to develop a suitable test program for these vehicles. These new scenarios depend more on the surroundings of the planned route, such as traffic lights, road markings, and other road users, than the route itself. The influence of these surrounding elements and their monitoring must be examined systematically with regard to the performance of the control units. It is important to take into account that a significant amount of these elements is subject to change over time and depending on location. With the FEV Advanced Road Rating System (ARRS), the tests for ADAS/AD vehicles are based on objective assessment criteria to enable a comparison of the various test routes. The focus of the ARRS approach is on objective and efficient robustness tests for ADAS/AD systems in the real world. This enables FEV to develop test methods for the validation of future technologies, such as ADAS/AD systems, systematically and efficiently.
Noise Vibration Harshness – NVH
Inner vehicle noise and vibrations are experienced firsthand by the end customer and therefore represent an important, often subconscious decision-making criterion for the purchase of a vehicle. On the one hand, they should be perceived as pleasant, but on the other hand, depending on the vehicle class, they should also express the dynamics and match the brand. The ambient noise of the vehicle is subject to legal provisions. On the one hand, pass-by noise is limited to reduce the strain on other road users and residents, and on the other, warning sounds are required of potentially very quiet electric cars for pedestrian protection (Figure 2). Acoustics and vibrations have to be taken into account consistently, across the complete vehicle development process, to achieve these NVH objectives. This begins with a decisive definition of the target values at the overall vehicle level. These are then used to derive target values for individual components, such as the engine, transmission, bodywork, and engine mounts, based on experiences with the predecessor vehicle, competitive comparisons, and the systematic assessment of noise transfer paths.
In the early phase of the development process, simulations support the design of the full concept and the detailed layout of acoustically relevant components. This includes, for example, the multibody simulation of the powertrain and the finite elements simulation of the bodywork. With the hardware’s increasing degree of maturity, the achievement of acoustic objectives will be checked with the execution of measurements and subjective assessments in the later course of the project. applicable, necessary optimizations are reported to those responsible for the part (see Figures 3 and 4).
This established process is facing new challenges due to the current trends in the automotive industry, such as electrification and autonomous driving.Click here to read the third part of the series.