Funding
Under the agenda of the high-tech strategy and the IKT2020 research program of the federal government, the University of Stuttgart began the interdisciplinary research project VALIDATE in July 2008 with the goal of reducing vehicular CO2 emissions. The 3.7 million euro project is funded by the Federal Ministry for Education and Research (BMBF) through June 2011. Full funding by the BMBF enables the design of a very powerful research platform that provides for the analysis of the benefits of future electronic control and assistance systems for motor vehicles. This analysis will provide both qualitative and quantitative results in either partial or complete virtual environments.
Project presentation
The main portion of the VALIDATE research project consists of the setup of a large driving simulator with which it is possible to develop driver assistance systems for intelligent support to reduce fuel consumption. Driving simulators represent a safe and economical way to test new systems in a virtual environment while using real drivers. In particular, the research will focus on assistance systems that will result in an indirect reduction of fuel consumption by influencing driving style. However, this requires a realistic recreation of the longitudinal and lateral accelerations, such as those occurring during a real trip and perceived by the driver via the organ of equilibrium in the inner ear.
In the structure of the VALIDATE project, this task is handled by an elaborate motion system using a combination of translatory motions in two directions (x and y) and rotary motions via a hexapod with six degrees of freedom. The vehicle environment (roadway, driving environment and traffic) is represented by a very detailed stereoscopic panoramic view. In addition, a spatial acoustic noise representation and a high-quality dynamic force feedback at the control elements (pedals, steering wheel, etc.) ensures a realistic vehicle and driver environment. This allows conducting meaningful studies with individuals and investigations of acceptance of the developed systems.
Another component of the project is a test vehicle that enables precise acquisition of energy flows inside the vehicle and the actions of the driver during everyday trips to determine saving potentials. For this, the energy flows in the powertrain, electrical system, and accessories are investigated. Everyday driving means that the vehicle is moving on a selected road network whose statistical properties correspond to the utilization profile of a given vehicle type or vehicle class matched as closely as possible. For the selected test course, which is part of the public road network, it was ensured that the distribution of road types (autobahn, country road, city streets) as well as the distribution of speed and uphill/downhill gradients closely corresponds to statistical vehicle usage data.
Another application of the test vehicle is the acquisition of environmental data, e.g. roadway courses, gradient profiles, traffic density, etc. This data can be used to derive virtual driving environments, for example to realistically study different configurations of a new driver assistance system in the driving simulator. The influences of the road are also taken into account for this purpose, such as route characteristics, road and surface condition. Furthermore, the collected data can be used to create load spectrums for the realistic operation of drive and electrical system components on the test bench. The measuring data obtained by the test vehicle can also be used for calculating the parameters of simulation models and for model validation.
A powerful real-time simulation and prototyping system is used for the simulation of the vehicle in the driving simulator. This simulation system consists of several independent networked computers that implement a simulation of the vehicle dynamics and powertrain as well as additional vehicle subsystems, e.g. the electrical system.
The rapid prototyping system allows modeling a new vehicle function by means of graphical development tools, e.g. a controller or an assist function, and immediately run it in real-time. Such a prototyping system is used in VALIDATE if a new operating strategy or assistance system is to be tested in different variants in conjunction with the driving simulator or the drive test bench.
The aforementioned drive and electrical system test bench, which is currently being assembled at the IVK, will also be integrated into the VALIDATE environment. The funds for this test bench have been approved by the University of Stuttgart and the German Research Foundation (DFG). This test bench allows for the study of various powertrains. In conjunction with the other VALIDATE components; it results in a variety of new testing possibilities that have never been implemented in this capacity.
Goals
The core of the VALIDATE research project is the construction of a research platform for developing electronic motor vehicle systems, e.g. powertrain and driver assistance systems, that enable a reduction of CO2 emissions. This platform allows a holistic quantification and optimization of fuel consumption in real driving. The goal of VALIDATE is to provide virtual evaluation and development methods for electronically controlled vehicle drives and assistance systems. VALIDATE will also concentrate on predictive control and assistance systems with which CO2 emissions can be significantly reduced.
In the framework of the project, the following factors will be researched:
- Investigation of CO2 saving potential of predictive systems for consumption reduction
- Researching possibilities of using combined driving environment sensor systems for consumption reduction
- Dimensioning of new drive and electrical system components, e.g. generators and batteries for conventional and hybrid vehicles
- Testing of driver assistance systems implemented as prototypes in a virtual environment
- Investigation of the dynamic interaction of operating strategies and drive components by combining powertrain test bench and driving simulator (HIL operation)
- Validation of simulation models for driving simulator and test bench by means of test drives
Utilization plan
The project results are intended to strengthen the economic and technological vehicle competency of the University of Stuttgart in Germany as a leading location for automotive industry and enhance the teaching and training of engineers.
For the economic utilization of project results, the VALIDATE project will be made available to interested companies in the automotive and supplier industry to test and validate new technologies and systems. The use of VALIDATE allows companies an early and reliable evaluation of new technologies and products in the sectors of electronic powertrain management, vehicle energy system and driver assistance.
During the development phases of a new product, from simulation to series-ready prototype, the development stages can be continuously tested and optimized in the VALIDATE environment.
As a result, the following potential approaches exist for vehicle manufacturers and system suppliers:
- Quantifying the energetic effects of new systems in future vehicle families by combining test drives (test vehicle) and a simulation of the new subsystems. Typical applications are electronically controlled, automated gearboxes of different configurations, generators, power electronics and batteries for an increased recovery of braking energy, electric accessories such as steering and air-conditioning as well as full and mild hybrid drives.
- Testing human-machine interfaces for driver assistance systems in the driving simulator.
- Testing electronic ECUs as well as drive and electrical system components up to complete motor vehicle drives, including hybrid technology in hardware-in-the-loop operation.
- The analysis of different variants and combinations of such systems allows reliable statements on which reduction of CO2 emissions can be expected in the standard cycle and in real operation.
Partners
Several institutes of the University of Stuttgart are participating in this research project. Combining the extensive expertise in the fields of automotive engineering, traffic infrastructure and virtual reality creates a research platform that will strengthen the leading position of the University of Stuttgart in vehicle research and simulation technology on a national and international level.