Method, arrangement and system for estimating vehicle cornering stiffness

Disclosed herein is a method, arrangement (3, 4, 5) and system for estimating one or more vehicle (1) cornering stiffness parameters ( c f , c r ) in a linear vehicle (1) operating region (11), where the method relied on comprises the steps of: reading sensor (2) data representative of at least vehicle (1) longitudinal velocity ( v x ), vehicle (1) lateral acceleration ( a y ), vehicle (1) yaw rate ( É z ) and vehicle (1) steering angle ( ´ ); determining from the read sensor (2) data if the cornering stiffness parameters ( c f , c r ) are observable; and if so providing an estimate of the cornering stiffness parameters ( c f , c r ) using a bicycle model that includes a model of tire relaxation dynamics.