A vehicle comprising a movable member mounted on the vehicle and movably attached to the vehicle, the movable member comprises at least one movable part and is movable within a movement range, the vehicle further comprises an arrangement to determine a real-time three-dimensional representation of said movable member, the arrangement comprises: - at least one object detecting device provided at said vehicle and configured to wirelessly capture information of objects of the movable member within a predefined field of view, the captured information comprises at least a distance and a direction to an object defining a coordinate in a three dimensional coordinate system, the object detecting device is configured to generate an object data signal comprising data representing captured information, - a processing unit configured to receive said object data signal, characterized in that each movable part is provided with at least one identification tag being mounted such that at least one ID tag of each movable part is detectable by said object detecting device within said field of view, the processing unit comprises a storage unit including type information of said movable member including at least the number of movable parts, a three dimensional CAD model of the movable member, and a set of various typical fictitious positions of the movable member, and that the processing unit is configured to process said object data signal by applying a set of tag identification rules and by using said type information, the processing comprises: - to identify ID tags being simultaneously captured, wherein the direction and distance, i.e. the coordinates in three dimensions, are available from the object data signal and the identity of the ID tag in that specific position is determined; - to group said identified simultaneously captured tags in a tag group; - to form, by using the tags in a tag group, a 3D representation of said movable member. - at least one object detecting device provided at said vehicle and configured to wirelessly capture information of objects of the movable member within a predefined field of view, the captured information comprises at least a distance and a direction to an object defining a coordinate in a three dimensional coordinate system, the object detecting device is configured to generate an object data signal comprising data representing captured information, - a processing unit configured to receive said object data signal, characterized in that each movable part is provided with at least one identification tag being mounted such that at least one ID tag of each movable part is detectable by said object detecting device within said field of view, the processing unit comprises a storage unit including type information of said movable member including at least the number of movable parts, a three dimensional CAD model of the movable member, and a set of various typical fictitious positions of the movable member, and that the processing unit is configured to process said object data signal by applying a set of tag identification rules and by using said type information, the processing comprises: - to identify ID tags being simultaneously captured, wherein the direction and distance, i.e. the coordinates in three dimensions, are available from the object data signal and the identity of the ID tag in that specific position is determined; - to group said identified simultaneously captured tags in a tag group; - to form, by using the tags in a tag group, a 3D representation of said movable member.