Development of an Intelligent System for Sheet Metal Bending

该项目旨在开发一种智能金属成形系统，特别是普通金属板材弯曲，该系统具有生产灵活性和高精度，并结合前馈控制。采用新开发的适用于位移控制的弯曲工具组，实现了板料变形的在线测量；利用实测数据对材料性能进行了估计，并结合刀具位移的高精度进行了计算。为了进一步提高控制精度，在控制系统中引入了神经网络。(1)在折弯机样机上，采用新研制的圆形或椭圆形折弯工具代替传统的v形折弯工具对板料进行折弯。从而证实，灵活性得到了提高，精度也提高了一倍。这是由于学习控制系统。(2)在上述试刀过程中，工件与刀具之间的接触点根据刀具的位移而发生位移。开发了一种智能传感器，可以测量法向和切向的力。可以测量接触点和弯曲角度。(3)在系统中引入描述复杂现象的神经网络，建立了精度较高的控制模型。将变形模型估计的材料性能输入到神经网络中，从而确定结合条件。由此可见，将可塑性模型与神经模型相结合，有可能成为一种高效、高精度的控制模型。

This project is to develop an intelligent metal forming system, in particular a common sheet metal bending, that performs flexibility in production and high accuracy incorporating feed forward control. By using a newly developed bending tool set which is suitable for displacement control, deformation of sheet metal is measured on-line ; the material properties was estimated by the measured data and combining with high accuracy of the tool displacement was performed. Further, a neural network was incorporated in the control system for further improvement of accuracy.(1) Instead of conventional V-angled bending tool, the newly developed tools of circular or elliptical shape was used to bend sheet metals on a prototype bending machine. It was thus confirmed that flexibility was improved and the accuracy was also improved by one fold. This is due to the learning control system.(2) In the above tool est, the contact point between the workpiece and the tool shifts according to the tool displacement. An intelligent sensor that measures the forces, both normal and tangential directions, was developed. The contact point and thus bend angle can be measured.(3) A neural network, which describes complicated phenomena was incorporated in the system to develop a control model with high accuracy. The material properties estimated by the deformation model was input into the neural network and binding condition was thus determined. It was thus concluded that combination of plasticity model and neuro-model has its potential of an efficient control model with high accuracy.