Abstract
Abstract:
The growing demands being placed on the infrastructure by ever-increasing transport volumes is driving the search for possible ways to ensure improved road safety for private transport. Since it is not only the vehicle, but also, to a considerable extent, the driver that is involved in exercising control and deciding on motion strategies, measures are required that offer optimal support and assistance to drivers, thereby preventing possible errors during the course of their driving duties. This is precisely where driver assistant systems come into play. The development and, in particular, the integration of these systems into the vehicle significantly increases the cost and functional content of today’s vehicles. However, the need to keep the complexity of vehicle systems under control and to keep the processes needed to integrated future functions into the vehicle at a manageable level requires not only the consistent application of new procedures and technologies, but also the development of forward-looking overall designs. This is an area where mechatronics can help raise the level of road safety, on the one hand, while at the same time improving the reliability of the overall vehicle system. Thus the aim of this paper is to present a modular mechatronic system based around the engine, transmission, axle, and steering components. The overall concept−an integrated power train that is designed to fulfill the holistic movement tasks using the driving, braking, steering and carrying functions−is realized on the basis of electronic actuation. The specification of a requested movement (direction and acceleration) at an electronic coordination level allows the power train to be controlled as a drive-by-wire module. This paper outlines various options in terms of system architecture design as well as the degree of function integration, with the aim of keeping the number of control units to a minimum. Other possibilities such as the incorporation of new assistance systems and alternative human-machine controls such as the sidestick are also addressed. Questions relating to the causes of accidents are discussed with a view to improving active traffic safety. The goal of future developments is to enable data from predictive and reactive systems to be used to avoid dangerous traffic situations before a driving command is executed. The use of recorded data to carry out a targeted evaluation of a vehicle’s surroundings before a validated coordinated target movement is passed on can help to reduce the number of accidents. Innovative systems such as tire sensing and the further development of electronically controlled chassis systems have significant contributions to make in this regard. On the one hand, this data can now being used to optimize current active safety by providing advance control for systems such as ABS and ESP. On the other hand, it can also be made available to other road users by means of telemetry, thus allowing data to be taken into account in a preventative and predictive manner. Along with issues relating to technical realization, the application of these systems in scenarios that may extend to partially autonomous driving also requires the consideration of issues relating to the acceptance of these systems by the legislature and society in general. The PEIT project (Powertrain Equipped with Intelligent Technologies), approved by the EU and carried out with an association of partners, has made a major, positive contribution in this respect. A drive-by-wire module with a standardized interface to allow the application of new assistance systems has been developed and presented as a prototype. Legislative and homologative requirements for system have been agreed. In the successor project SPARC (Secure Propulsion using Advanced Redundant Control), which has been running since January 2004, this power train module will be connected, as part of the overall vehicle design, to a digital level in the driver cockpit and connected to the combination of existing and future assistance systems as a “virtual driver”. In the case of commercial vehicles in particular, additional consideration is given to the combination of tractor and trailer/semi-trailer because most of the vehicle weight is concentrated on the accompanying top carrier. Finally, the paper expounds the benefits offered by the consistent use of mechatronics in designing vehicle platforms. This means that the system architecture presented here can be applied both in commercial vehicles and passenger cars simply by changing the mechatronic components such as the engine, transmission, axles and steering system.