Page - 6 - in Maximum Tire-Road Friction Coefficient Estimation

1 Introduction driver actuated vehicle environment stabilisation course planning navigation VDC warning ADAS intervening ADAS driving tasks vehicle Figure 1.4.: Simplified representation of driving process including the elements driver, vehicle and environment based on Niederkofler, [Nie11, p.106]. Warning ADAS target the driver directly. Driver and intervening ADAS both un- dertake driving tasks, requiring human machine interaction. VDC directly actuate the vehicle on the stabilisation level, but do not necessarily require interaction with the driver. Thus, the connection to this driving task is not shown in this depiction. In this work, the term VDC denotes all safety systems on the vehicle level that act on the stabilisation level without a direct feedback loop including the driver. Therefore, Figure 1.4 shows VDC as an internal closed loop of the vehicle. Controller outputs for the actuators are calculated using vehicle dynamics state variables, in order to minimize the difference between the nominal and actual values, [Ras09]. Many sources classify VDC as a subgroup of ADAS, e.g. [WHW09a]. In the present thesis, ADAS denotes all systems working on the navigation, course planning and stabilisation level, that directly include the driver in a feedback loop. A strict differentiation in VDC and ADAS on the stabilisation level is difficult. In general, ADAS can be divided into warning and intervening systems. Here, it is assumed that ADAS include only warning systems on the stabilisation level, whereas VDC include all intervening systems. This classification is chosen to emphasise the different requirements on control variables within VDC and ADAS which are discussed in Sections 1.3.2 and 1.3.3. For example, the requirements for the estimates to be used within VDC are very high due to the time characteristics and the safety-critical nature of VDC. 6