A METHOD FOR DETERMINING A DRAG TORQUE COEFFICIENT

A method for determining a drag torque coefficient (b) of a transmission. The method comprises performing rotational speed synchronisation involving application of synchronisation torque (T) to a first transmission component (32, 34), and obtaining an initial rotational speed of the first transmission component (32, 34) before the rotational speed synchronisation, and a final rotational speed of the first transmission component (32, 34) after the rotational speed synchronisation, and time period for performing the rotational speed synchronisation. The method further comprises obtaining information relating to a level of the synchronisation torque (T) applied to the first transmission component (32, 34) during the rotational speed synchronisation, and obtaining information relating to a total moment of inertia (J) associated with the first transmission component (32, 34). In addition, the method comprises determining the drag torque coefficient (b) based on the obtained initial rotational speed, the obtained final rotational speed, the obtained time period, the level of the applied synchronisation torque (T) and the total moment of inertia (J) associated with the first transmission component (32, 34). Furthermore, the disclosure also relates to corresponding transmission system.