Validation of a Moving Base Driving Simulator for Subjective Assessments of Steering and Handling

Abstract

An important step in automotive development to evaluate the steering and handling characteristics of a vehicle is through physical subjective assessments and testing. This allows for a thorough understanding of how the vehicle behaves when driving and how it will be experienced by the customer. However, as physical subjective assessments and testing require real vehicles to be driven on a real track, it is rather inefficient time-wise, costly, and sensitive regarding repetitiveness and to surrounding conditions, compared with using digital development tools. Due to these drawbacks, the general trend in the automotive industry is to move an increasing amount of the development of vehicle steering and handling dynamics from using physical tools and methods to digital ditto. This does however require that the digital tools used provide reliable and trustworthy results, a validation of which is the main purpose of the thesis project presented in this report. The focus here is to validate the partly digital development tool that is the Moving Base Driving Simulator existing at Volvo Cars. This is performed by generating virtual vehicle models of a physical vehicle through measurements in a kinematics and compliance rig. The measurements are performed with three different antiroll bar configurations, thus generating three different vehicle models. The vehicle models are validated by simulating them driving certain manoeuvres, and driving the same manoeuvres in the physical environment in the same vehicle specimen as is used throughout the whole project. After tuning and validation, the virtual vehicle models are used as input to the Moving Base Driving Simulator. Performing a physical subjective assessment in the same vehicle as was measured in the kinematics and compliance rig, and another subjective assessment in the Moving Base Driving Simulator with the same layout, allows for a validation of the simulator by comparing the results. The project is thus covering all major steps included in vehicle dynamics development including kinematics and compliance measurements, generation, analysis and simulations of virtual vehicle models, physical objective measurements, and finally subjective assessments in a physical vehicle and in a driving simulator. The outcome of all stages are presented in this report and shows for example that 94% of the assessed handling characteristics and 78% of the steering characteristics change in the same direction in the physical and virtual subjective assessments when changing the antiroll bar configuration of the vehicle.