General Scheme for Automatic Control of Continuous Bending of Beams

The paper addresses the problem of automating the process of continuous bending of metal beams. The history of previous efforts along these lines is presented and a comparison of this problem with that of numerical control in metal cutting is made. A mathematical model of the bending process suitable for a control system is presented. The uncertainties due to springback and the stochastic nature of bending properties of the beam material are discussed. The needs for parameter identification and output prediction are described. A block diagram for a closed-loop system to control this process is introduced. Results are presented which demonstrate that it is possible to bend to desired curvature if the springback characteristics are known. It is concluded that automatic control of this process is feasible making possible continuous bending of beams into arbitrary desired shapes.