SPARC: Test platform for drive-by-wire equipped vehicles in development and productionCopyright: © Thomas Knobloch
It is generally assumed that the use of electronic vehicle systems will increase considerably in the next few years due to various interest groups. Legislators want to optimize vehicle exhaust gas properties and minimize fuel consumption, while customers are interested in driving comfort and safety. In addition, OEMs are continuously improving their vehicles by creating complex systems with new functions that the customer cannot even imagine today. This technology is already built into the C5 Corvette, Acura NSX and Toyota Tundra and we can expect a growing number of new vehicles with this technology.
One of these futuristic developments is the so-called X-by-wire systems. The exclusively electronic control of the vehicle's mechanical components, also known as drive-by-wire technology, is becoming increasingly important. The goal for the future automotive driver assistance systems should be based on a common electronic platform which, in addition to the reduction of mechanical components, also includes the economisation of production processes.
Drive-by-Wire at a glance...
- Substitution of mechanical connections by mechatronic components
- Backup of each function from the computer control
- Multiple protection by redundant systems (Duo Duplex)
- Intelligent sub-controllers for each mechatronic component
- Intervention in the driving (re-)action through intelligent systems
Some of the advantages of Drive-by-Wire are:
- The extinction of the "LHD / RHD - Problem"
- Autonomous parking, even with a trailer
- Time saving
- Accident avoidable driving
The first step in creating a reliable test platform is to identify the components that need to be tested in a vehicle equipped with Drive-by-Wire and clarify the test cycle to ensure that all the functionality of the X-by-Wire components is completed.
For this purpose, it is necessary to develop a new generation of test benches in which new X-by-wire functionalities can be integrated. As an example, the functionality of the extended ESP, a vehicle body stabilizing function with breakage and steering interaction, can be cited. In addition, an autonomous vehicle must respond to dangerous situations such as automatically avoid accidents with pedestrians when crossing the road or other unpredictable traffic situations. This requires a decision control unit that compares the driver's "wish" motion vector (initialized via HMI - Human Machine Interface) with a so-called safe motion vector generated by the environmental sensors.
Testing such scenarios on available test benches is not possible at the moment because the steering function tests are not included and the so-called ECOS Electronic Tests cannot assure that the intercommunication between the control units in the vehicles equipped with X-by-wire is correct.
With the so-called 4CS (Car Communication Component Check System) it is possible to carry out system integration tests in the laboratory and in the environment of the vehicle in a completely automated manner. The tests are carried out with the so-called "button-up strategy" and are well known for the MOST system, which was developed in cooperation between DaimlerChrysler AG and BMW AG.