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

rα lateral tire relaxation length Rmin turning circle of vehicle s combined slip vector sx(y),i longitudinal (lateral) slip in contact patch of i-th wheel sα lateral slip (alternative definition for lateral tire dynamics, see Appendix B.2) S covariance matrix t time ∆t time interval between two discrete time steps k+1 and k tj track width of j-th axle T measurement time (radar sensor) Tgb rotation matrix from vehicle-fixed to global coordinate system Tbi rotation matrix from i-th wheel-fixed to vehicle-fixed coordinate system TTC time-to-collision u exemplary variable u control vector Ue effective rolling circumference of tire v vehicle’s velocity at COG vC,i translational velocity of i-th wheel centreC vC,x(y) longitudinal (lateral) component of velocity of wheel centreC vS sliding velocity in contact patch vS,x(y) longitudinal (lateral) component of sliding velocity in contact patch vx vehicle’s longitudinal velocity at COG vx,0 initial longitudinal velocity of vehicle at COG v¯x(y) vehicle’s normalised longitudinal (lateral) velocity vmaxx vehicle’s maximum longitudinal velocity ∆vx relative velocity between vehicle and obstacle ∆v¯x resolution of ∆vxmeasurement with radar sensor vy vehicle’s lateral velocity at COG w exemplary variable wref reference value from reference simulation wvar value from parameter variation W wheel contact point according to ISO 8855, [fSI11] xv