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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et al. (2020) a method for automated test course generation on the basis of customer-oriented usage data is developed. By designing the course on the basis of the transferable general driving behavior, the load spectra can be determined by means of a driving operation measurement with a prototype of the new target vehicle. 2.2. Load monitoring in the durability road testing experiment In order to monitor compliance with the testing requirements during the durability road testing experiment, there are basically two indicators that can be taken into view: Firstly, the abidance by the prescribed driving instructions (for example speeds, braking points, etc.) and secondly a measurement as well as a comparison of the generated loads. As an example for the first method, Teutsch et al. (2010) presents a driver guidance system which compares the actual speed with the target at the actual GPS position. In addition, the further route guidance is calculated in such a way that an optimal utilization of the sections on the proving ground is realized for all vehicles driving at the same time. This first variant is particularly suitable for test courses, which have a very precise prescribed driving instruction. Otherwise, it may be more appropriate to measure the generated loads and to compare them with the test target. For example, Heiden et al. (2014) introduces a system that analyzes the load measurement data during the durability road test and plots the pseudo-damage above the mileage to show whether it is in the desired corridor. Such an approach comprises the challenge of setting a suitable target-damage, since it is highly vehicle type dependent. In comparison, the load monitoring allows a more detailed analysis and a better assessment of the fulfilment of the testing requirements. However, since this can only be done in the aftermath, the possibility of influencing the test driver is minor in relation to an onboard guidance system for a monitoring of the driving instruction-abidance. The new developed intelligent driver guidance system presented in this article aims at a hybrid solution that combines the advantages of both approaches. 3. Preparations 3.1. Task and goals The basic idea of the new driver guidance system consists in a calculation of a flexible further route on the basis of the already endured loads in such a way that the target load spectra are achieved as well as possible. The system should be designed so universally that it can be used for any type of target spectra, both in terms of the physical values and the employed counting algorithms. On the one hand, it is intended to carry out a monitoring of the endured loads by recording sensor data, but on the other hand it should give the driver an easy-to-understand driving instruction. In addition, the monitored valuables as well as the target spectra should be related to standard vehicle internal sensors. This implements a customer-oriented test by reproducing a realistic driving style from field data and enables the required transformation to load values in a simple way within the practical experiment, rather than in complex calculations. 3.2. Map data For the design of the route planning already known techniques from common navigation systems are used. By converting the road network of the test area into a mathematical graph, a digital map is generated. In the conversion, road sections are interpreted as edges and intersections as nodes, Fig. 1. The input consists of map data from “O penStreetMap, which are free of charge and provide good quality. In the modelling process, only roads that are passable during a test drive are taken into account.