The invention relates, among other things, to an
estimation device (1) for determining a new estimated motion value (v_virt), which indicates the speed of a railway vehicle (200) having at least two axles, comprising: a
Kalman filter (30), which is fed on the input side with at least torque values (m_p_i, m_e_i),
vertical force values (Q_i), wheel size values (r_i) and wheel speed values (ω_i) and on the basis of these, as well as on the basis of a
Kalman filter, determines a Kalman estimated vehicle speed value (v_k);a slip module (40), which receives on the input side the values of the torque (m_p_i, m_e_i), the values of the wheel size (r_i), the values of the wheel speed (ω_i) and the respective previous estimated motion value (v_virt) from the estimating device (1), and determines a circumferential speed value of the wheel (v_umlauf) and a slip indication, which indicates any slippage of the respective axle; and an evaluation module (50), which determines the new estimated motion value (v_virt) of the estimating device (1), based on the Kalman estimated vehicle speed value (v_k), the circumferential speed value of the wheel (v_umlauf) and the slip indications.