Abstract
Efforts in the field of passive safety have reduced the number of injured persons in accidents substantially. However, many active safety systems that are able to avoid or mitigate accidents are becoming more and more important. The evaluation of the expected benefit of such systems or even ideas of future systems is challenging because this has to be done prospectively. Beside acceptance, the predicted real-world benefit of active safety systems is one of the most important and interesting measures. Therefore, appropriate methods should be used that meet the requirements concerning representativeness, robustness and accuracy.
The main aim was the development of a methodology for the assessment of current and future vehicle safety systems. It was considered that the variety of systems requires several tools and methods which are now integrated in a common tool box. This toolbox consists of three levels. The first one focuses on data and scenarios. Mostly, accident databases like GIDAS are used for the estimation of effectiveness in accident situations. Furthermore, NDS data can be used for analyzing the acceptance. Also aspects like representativeness are considered in this part. In the second level the safety systems are evaluated by different measures like pre-crash-simulations, automated crash computation, single-case-analyses or driving simulator studies. Finally, the benefit of the system(s) is calculated, e.g. by using injury risk functions; giving us the number of avoided/ mitigated accidents, the reduction of the injured or killed persons or the decrease of economic costs.
The procedure and complexity of benefit analyses for active safety systems strongly depends on the system functionality. Currently, a large variety of functions, sensors and algorithms are existing; aiming at the avoidance or mitigation of accidents. Thus, it is hardly possible to create a universal method for the evaluation of every conceivable system. However, the presentation gives an overview about the developed toolbox, where available benefit estimation methods are united and combined. Furthermore, the procedure of a complete benefit estimation is shown with an example of a current active safety system for passenger cars. To demonstrate the capabilities of the toolbox, a complex assistant for crossing traffic situations is chosen for the application of the toolbox.
The quality of benefit estimations always depends on the availability of appropriate data, the accuracy of the used methods and the possibility of being representative for a country or even a bigger region like e.g. the EU-27. The presented method will also focus on the achievable accuracy of benefit estimations.
The paper shows a comprehensive method for the benefit estimation of vehicle safety systems. The experience of many single studies and the variety of available methods are summarized in a common toolbox. The method allows a standardized benefit estimation of active and passive safety systems. One important thing is that the system must not necessarily be developed yet. It is also possible to predict the future benefit of systems or system ideas.
KEYWORDS – Benefit estimation, Injury Risk Function, Accident simulation, Field of operation,