METHODS AND PROCEDURES FOR TESTING THE E-CALL IN VEHICLE UNIT FOR THE PURPOSE OF ITS PERFORMANCE ASSESSMENT AND CERTIFICATION

摘要

The main idea behind the pan-European eCall project is to automate the emergency call that is simultaneously extended by a message containing information such as current position and prior-to-crash speed, type of vehicle, VIN, VRN, number of passengers travelling, etc. The in-vehicle unit consists of measurement, communication, positioning and user-interface sub-systems, and all those sub-systems need to pass functional and performance type examinations before the device can be granted formal approval from the notified laboratory. The usual way of testing the module will be during the type approval of the car, as performance of the unit is strongly correlated to the dynamical parameters of the vehicle body and fitting procedures. Technology of today makes it relatively easy and straightforward to measure linear and angular accelerations of the vehicle chassis to estimate its full state in the 6-DOF space, however, the number of sensors required and resulting cost is mostly prohibitive, thus in practical solutions the crash detection is to be implemented based on signals acquired from a limited number of available sensors, preferably already present in the existing set-up, using also additional sources of data, such as longitudinal velocity from the speed sensor. The purpose of the project is to design a testing methodology and set-up a testing bench for the type certification of the in-vehicle e-Call system units for the accredited laboratory. The test stand should allow the production of precise and repeated predefined testing conditions to excite the device-under- test sensors and to relate their logged data and results to those of reference set of sensors built-in to the test stand. Another question we address during the study is the feasibility of data gathered in the in-vehicle e-Call unit for the purpose of reconstructing the crash.