Abstract: Tow bar arrangement (100) for interconnection of a pulling vehicle (10) and a pulled trailer (20). The arrangement (100) comprises a control device (110) with a force sensor (111) arranged to sense an instantaneous relative force between vehicle (10) and trailer (20). The control device (110) is arranged to produce a control signal for an electric motor (21) arranged to propel the trailer (20) so that a motor force counter-acts said measured force. The invention is characterised in that the control device (110) is arranged to a first time series of force measurements, in that the control device (110) comprises a low-pass filter (112) producing a second low-pass filtered time series, and in that a regulator (113) is ar-ranged to regulate said second time series to produce said control signal.