Alexander Flach

CAR-2-X and Pedestrian Safety

Traffic accidents involving pedestrians or cyclists cause thousands of fatalities and serious injuries every year. In this article, we present an innovative approach for a collision avoidance system that seeks to reduce these accidents. We also discuss the different architectural approaches utilizing ad hoc and/or cellular technologies and different processing setups and present a physical analysis of the system time available between detection, warning, and reaction to give an overview of the time constraint.

A Physical Analysis of an Accident Scenario between Cars and Pedestrians

Every year still thousands of people are injured or killed in accidents with cars, trucks and busses. Many of these people are pedestrians or cyclists. Several research groups work on solutions to avoid accidents between cars and pedestrians with the help of different technologies. In this paper we present an innovative approach for a collision avoidance system which should be able to tackle these accidents. To understand the potential of this approach, we will present a physical analysis of the system time available between detection, warning and reaction. We also discuss different architectures of our approach utilizing ad-hoc and/or cellular technologies. Additionally, we present experimental results of connection establishment and ping response times of these wireless technologies.

Pedestrian Movement Recognition for Radio Based Collision Avoidance: A Performance Analysis

In todays increasingly mobile society, car manufacturers and suppliers worldwide face the imperative requirement and have already been working to reduce the number of people killed in traffic accidents. In this context pedestrian protection respectively collision avoidance between cars and pedestrians is of vital importance. Several approaches exist to detect pedestrians but only a few of them are able to work without line of sight and/ or only have a very brief view of the movement history of the pedestrian. However, radio communication based systems which exchange GPS based position information of the pedestrian and the car might have a detailed view to the movement history but the update frequency of GPS positions provided by the mobile phone reduces the speed of the system and might induce false alarms. In this paper, the additional use of pedestrian movement recognition using an acceleration sensor implemented in a mobile phone in the area of collision avoidance between cars and pedestrian is presented and a performance analysis is carried out using the results of an experiment. Finally, the benefits of this approach to the reduction of false alarms and detection of endangered pedestrians are discussed.

Combining Radio Transmission with Filters for Pedestrian Safety: Experiments and Simulations

Improving the safety of vulnerable road users is an international demand because still thousands of pedestrians and cyclists are injured or killed in accidents with cars, trucks and busses. Car manufacturers and several research groups work on different solutions to avoid accidents with the help of sensor based systems. Moreover, research is done in radio communication based collision avoidance systems which uses exchanged information to distinguish between dangerous and non dangerous situations. In this paper we present various filters differing by the input information used to find dangerous situations implemented in a radio based collision avoidance system simulator. The results of the filters applied to a scenario are also presented. Furthermore, we analyse the influence of different conditional parameters to transmission delay times by taking further measurements for cellular networks to determine if cellular networks can be used as a communication technology in a collision avoidance system.

Car and Pedestrian Collisions: Causes and Avoidance Techniques

Pedestrian safety is of vital importance and of increasing interest worldwide. New legislation passed to heighten pedestrian safety as well as car manufacturers’ own ethical goals have precipitated the search for viable solutions as to how to best protect pedestrians. In order to fulfill these legal requirements, car manufacturers and various research groups employ different technologies to develop passive and active pedestrian protection systems.