Page - 71 - in Integration of Advanced Driver Assistance Systems on Full-Vehicle Level - Parametrization of an Adaptive Cruise Control System Based on Test Drives

6 Upper Level Controller Parameter Identification 6.1. Non-Linear Time Gap Controller The investigated Adaptive Cruise Control (ACC) controller is based on the Continuous Time Gap (CTG) controller of eq. (2.28). For comfort reasons, small errors in the position or velocity of eq. (2.23) and eq. (2.24) should lead to small desired accelerations ades. Thismay leadtoproblemswhenaplatoonofvehicles, eachequippedwiththesame CTG controller, is travelling at steady state and the first vehicle decelerates. Figure 6.1 illustrates this situation for the vehicles with the number 1 and i−1 to i+1. Accordingto [LP99], thevehiclemotionof the i−1-thandand i-thvehiclearedescribed by τlong ... xi−1 + x¨i−1 =P3 [r˙i−1 +P4(ri−1−s0−vi−1 τset)] and (6.1) τlong ... xi+ x¨i=P3 [r˙i+P4(ri−s0−vi τset)], (6.2) using thevehiclemodel of eq. (2.25)andthegeneralCTGcontroller of eq. (2.28) reading ades=P3 (er˙+P4er). (6.3) The inter-vehicle distance and velocity are defined by ri = xi−1− lveh,i−1−xi and its