Poster Presentation

Prof. Dr.-Ing. Dr. h. c. Albert Albers , IPEK - Institute of Product Engineering; Karlsruhe Institute of Technology (KIT), Germany
Dipl.-Ing. Sarawut Lerspalungsanti, IPEK - Institute of Product Engineering; Karlsruhe Institute of Technology (KIT), Germany

This paper presents a successful implementation of a methodology for NVH phenomenon evaluation carried out on the example of the gear rattle. The main purpose is to determine the NVH properties of a 5-speed manual transmission in view of gear rattle tendency and its effect on an entire system, especially the vehicle interior noise, in the early phase of product development process. Based on the X-in-the-loop approach of drive train development, presented in Figure 1, investigations and assessments of transmission noise can be performed in different test environments, such as test benches or fields depending on the applied evaluation criterion. In this study, two criteria are defined. The first criterion is aimed at studying the phenomenon itself and to verify the gearbox performance. The dynamic drive train test bench allows the investigation under the same boundary conditions without interference of other sources like the combustion engine. To predict the tendency of the gear rattle presence and evaluate the resulted annoying level, the user-friendly human sensation modeling tool is used. This has been developed based on the Artificial Neural Networks (ANN) and is already successfully applied for vehicle start-up analysis and ratings. To consider the second criterion, the customer-oriented evaluation of the gear rattle is carried out in the car using the presented tool. Experiments on the acoustic roller test bench and in the field are aimed to assess the interior noise based on the passenger perception of the gearbox behaviour at different driving situations such as idle or stop-and-go. In comparison to an investigation in the field, one on the roller test bench enables the same boundary conditions like runway friction coefficient or aerodynamic drag by simulation of environments. From the experimental results, the relationship between the objective parameters captured in different X-in-the-loop environments and the subjective comfort ratings based on both criteria is determined. Consequently, the elaborated human sensation models can be effectively applied to compare different gearbox solutions for future product by estimation of the gear rattle tendency and by prediction of the passenger comfort rating based on the experimental as well as simulation data. Additionally, the applied method for comfort enhancement such as the installation of a dual mass flywheel can be validated concerning the customer satisfaction.

This abstract is supplemented by a PDF, which can be viewed here.

Poster presentation: Test, simulation and calculation methods of vehicles and components