Page - 85 - in Maximum Tire-Road Friction Coefficient Estimation

4 Sensitivity Analysis 0.2 0.4 0.6 0.8 1 -20 -15 -10 -5 0 5 -3 -2 -1 0 1 x104 -60 -40 -20 0 20 -10 -5 0 5 -4 -3 -2 -1 0 1 -10 -5 0 5 -8 -6 -4 -2 0 2 v x v y b w z w fl w fr w rl w rr b a x =4, b a y =1 µmax µmax µmax b a x =3.5, b a y =4x103 x10 x102 b a x =2.5, b a y =5 b a x =1.5, b a y =3 b a x =2.5, b a y =1x10 b a x =0.2, b a y =1 b a x =0.5, b a y =4x103 1.2 0.2 0.4 0.6 0.8 1 1.2 0.2 0.4 0.6 0.8 1 1.2 0.2 0.4 0.6 0.8 1 1.2 0.2 0.4 0.6 0.8 1 1.2 0.2 0.4 0.6 0.8 1 1.2 0.2 0.4 0.6 0.8 1 1.2 Figure 4.14.: Normalised sensitivities for all state variables for selected acceleration data points in Region 4 (positive longitudinal and lateral excitation). Sensitiv- ities for vx, vy and bωz are close to zero. 4.5.3. Sensitivities for front-braked vehicle (theoretical) To investigate the influence of the brake torque distribution between front and rear axle, theextremeandtheoretical caseof only frontbraking (100%brake torqueon frontaxle) hasbeen investigated. Thesimulationreproducedsamemanoeuvresandthe same initial vx,0 as the simulationof theconventionalbrake systemin Region 2. For theconventional braking system (as shown in Figure 4.12), the curves for the wheel speeds on the front 85