Revised Simulator validation – a new methodological approach applied to motorcycle riding simulators

Whenever driving simulators are used in research and development, to a certain extent the generalizability of the gained results is subject to discussion. Typically, a simulator gets validated in a rather effortful and complex process to prove the adequacy of the use of this specific simulator as research tool for a given research question. Traditionally, there is a differentiation between a simulator’s physical validity and its behavioral validity. Whilst the first focusses on the simulator’s behavior and the presence of specific cues and operating elements, the latter focusses on the driver’s perception and consequently behavior. Furthermore, the degree of accordance between vehicle and simulator forms a category of validity, namely, absolute, and relative validity. Whilst absolute validity describes an absolute numerical accordance of measurable dimensions between vehicle and simulator (e.g., certain forces, accelerations), relative validity describes a correlational accordance. Independent of the addressed dimension, simulator validation is a highly complex process, which is specific to the respective research question for which the simulator gets validated (e.g., training race riders vs. assessing distraction caused by human-machine interfaces, HMI). Regarding single-track vehicle simulator concepts for which there is less experience from previous research, a rather broad validation procedure would be a useful tool to assess a simulator’s overall characteristics and therefore to assess its potential fields of application on a wider basis. This paper addresses this gap and presents such a methodological validation approach applied to motorcycle riding simulators. The main assumption of the method is that complex riding tasks can be divided into smaller units that allow for discrimination of specific rider input characteristics, the so-called minimal scenarios. These minimal scenarios are riding tasks such as ‘starting from standstill’ or ‘initiating a curve at constant velocity’. Furthermore, it is assumed that minimal scenarios can be reorganized to more complex riding tasks. This is intended to describe the variety of potential applications with a necessary minimum of elementary tasks to reduce the validation effort for a global assessment of the simulator’s capabilities. This more generic result can also be regarded as a limitation. The proposed empirical evidence from participant studies on a static, a dynamic motorcycle riding simulator as well as a reference ride on a real motorcycle suggests that the validation approach can be beneficial.