Apparatus for and method of controlling tension of a filamentary material

An apparatus for regulating tension of a filamentary material, said apparatus comprising:

• a brake wheel;
• a force sensing element arranged to sense a tension on said filamentary material and for producing an actual tension signal indicative of said sensed tension;
• motor means coupled to said brake wheel for driving said brake wheel and for generating a rotor position signal indicative of a sensed position of a rotor of said motor means;
• a motor control unit responsive to said motor means for producing an amplified rotor position signal in response to said rotor position signal, for supplying an energy signal to said motor means, and for generating an actual torque signal derived from said energy signal;
• setting means for setting a wire tension value and for generating a set wire tension value signal indicative of said set wire tension value;
• and
• a control device connected to said force sensing element, said motor control unit, and said setting means, and which receives said amplified rotor position signal, said actual torque signal, and said set wire tension value signal, for comparing said actual tension with said set wire tension value, for producing a correcting signal at least partially on the basis of said comparing, and for transmitting said correcting signal to said motor control unit for controlling said energy signal to convert said actual tension to a desired tension represented by said set wire tension value.

A method for regulating tension of a filamentary material wound between a pair of rollers and around a brake wheel, said rollers and said brake wheel being driven by a motor means, said method comprising the steps of:

• detecting an actual tension of said filamentary material;
• generating a rotor position signal associated with said motor means, an actual torque position signal according to energy supplied to said motor means, and a set wire tension value;
• determining correction signals for wire speed and wire acceleration based on said rotor position signal;
• comparing said actual tension with said set wire tension value and generating a difference signal;
• correcting said difference signal according to said correction signals and generating a corrected difference signal;
• comparing said corrected difference signal with said actual torque position signal and generating a resulting signal;
• converting said resulting signal into an energy supply signal for said motor means;
• and
• transmitting said energy supply signal to said motor means.