Development of a new model based servo-controlled wire tensile force control for stator winding applications

Due to the electrification of the automotive powertrain new challenges in production technology must be faced. For direct winding processes of non-circular bobbins, the control of the wire tensile force is crucial for the winding quality and displays one of the greatest challenges. Within this paper a new approach to control the tensile force along the winding trajectory will be introduced. As a first use case, the application of this approach for linear winding technology is presented. The potential of the model based servo-based wire tensile force control is demonstrated through systematic winding experiments. Since the control strategy does not solely rely on a measurement of the wire tensile force but also on the modeled behavior of the wire length, precision winding schemes can be achieved at significantly increased winding speeds. Secondly the transfer of this technology to the more complex multi axis needle winding kinematics will be presented. Finally the implementation of the control strategy in the needle winding machine will be shown and a validation with winding experiments is provided.