Stretching-bending-straightening system and method of the actuation thereof

A stretching-bending-straightening system, having

• a feed means for feeding a material in strip form in a movement direction into a high-tension region and a low-tension region, wherein the low-tension region is arranged downstream of the high-tension region in the movement direction,
• a bending-straightening apparatus, which is situated in the high-tension region,
• at least one measuring system for determining first measured values in the high-tension region,
• a controller, which is intended and suitable for determining a deviation of the first measured values from a predefined or predefinable desired value of the bending-straightening result and for determining at least one manipulated variable for the bending-straightening apparatus depending on the determined deviation within a first closed control loop,
• an adjustment means for influencing the manipulated variable,
• wherein there is provided in addition at least one measuring system for determining second measured values in the low-tension region,
• wherein a controller is intended and suitable for determining a deviation of the second measured values from the predefined or predefinable desired value of the bending-straightening result and for determining the at least one manipulated variable depending on the determined deviation within a second closed control loop, and
• wherein selection means are provided and are intended and suitable for selecting the first closed control loop or the second closed control loop in order to reduce the deviation of at least one of the first or second measured values from the predefined or predefinable desired value.

A method for operating a stretching-bending-straightening system, said method comprising the steps:

• feeding a material in strip form in a movement direction into a high-tension region and a low-tension region, wherein a bending-straightening apparatus is arranged in the high-tension region, and wherein the low-tension region is arranged downstream of the high-tension region in the movement direction,
• determining first measured values in the high-tension region,
• determining a deviation of the first measured values from a predefined or predefinable desired value of the bending-straightening result,
• determining at least one manipulated variable for the bending-straightening apparatus depending on the determined deviation within a closed control loop,
• determining second measured values in the low-tension region,
• determining a deviation of the second measured values from the predefined or predefinable desired value of the bending-straightening result,
• determining the at least one manipulated variable depending on the determined deviation within a second closed control loop,
• selecting the first or the second closed control loop in order to reduce the deviation of at least one of the first or second measured values from the predefined or predefinable desired value.