PSI - Issue 38

Florian Grober et al. / Procedia Structural Integrity 38 (2022) 352–361 Grober, Janßen, Küçükay / Structural Integrity Procedia 00 (2021) 000 – 000

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On the left side the road network of the digital map is shown. A triangular symbol represents the vehicle’s current position. The vector between the last GPS samples received aligns the map according to the current direction of the driver's view. By means of the plus/minus buttons the zoom can be set within defined intervals. A light blue line shows the interpolation between the last GPS samples and thus the recently driven way. Moreover, a red line indicates the route to be driven next. The right side of the interface consists of several panels. Within the left column, the instruction concept for the driver is realized with three elements: a target velocity, a braking prompt and a turning direction. To the right of the target speed, its current value is displayed. A traffic light coloration (green, yellow, red) notifies whether it is in the correct range. The braking request is represented by a stop symbol. It indicates that the driver must decelerate to a specified lower velocity or stop at a suitable location within the current road section. As soon as the speed has been reduced accordingly, the stop symbol is replaced by a green check mark as acknowledgment. To display the turning instructions for the next two road intersections, directional arrows are used. All guidance notifications are also announced by an audio output, so that the driver can keep the view on the road. Furthermore, there are two panels in the right column to display the daily as well as the total covered kilometers. In addition, there are various buttons to display the actual test level, to make settings, to mute the audio output as well as to terminate the program. 5.2. Process description Each time a new GPS sample is received, the map display is updated and it is checked whether the vehicle has reached a new edge of the road network. If so, the recorded loads of the last completed edge are stored in the experience database in order to keep it up to date. Furthermore, the actual test level is calculated in order to use it later as the basis for the route decision. Thereafter, the algorithm checks whether the intended turning maneuver has been carried out correctly. If this is the case, the previously determined instructions for the newly reached edge are displayed and announced. Subsequently, the route decision for the next node is made by means of the presented heuristic algorithm. However, if the driver has taken a wrong way, no instructions are displayed and the route planning is carried out directly. 5.3. Prototypical implementation In order to test the presented new driver guidance system, it was realized prototypically at Volkswagen AG. The program ‘MATLAB App Designer ®’ served to implement the described algorithms and to shape the user interface. By using the ‘V ehicle Network Toolbox ’ , the application was able to receive signals from the CAN bus and process them in real time. For this purpose, a laptop was connected to the CAN bus of the test vehicle with a ‘Kvaser USBcan II’ device . Thus, measurement data of the vehicle-internal sensors became available. Due to ergonomic reasons, a display was attached in the middle of the cockpit to visualize the user interface of the application to the driver, Fig. 5.

Fig. 5. Prototypical implementation of the driver guidance system with a cockpit display.