金属板材弯曲测试装置控制系统设计及试验分析

Design and experimental analysis of control system for metal sheet bending test apparatus

针对仅通过单轴拉伸试验无法准确表征材料在弯曲过程中力学性能变化的问题,设计了基于模糊比例积分微分(PID)控制的金属板材弯曲测试装置控制系统.首先,给出了控制系统的总体设计;然后,为了确保装置运动过程的稳定性,建立了装置的机电耦合仿真模型,并提出基于模糊PID的自适应控制方法,以实现装置工作过程中PID控制器参数的自适应在线整定;最后,搭建金属板材弯曲测试装置控制平台并对高强钢DP980进行弯曲测试试验.结果表明:采用基于模糊PID自适应控制方法的平台定位误差测试结果为±0.005°,降低了轴向力对板材弯曲过程的干扰;弯曲试验获得的高强钢DP980的力学性能参数与拉伸试验得到的参数存在明显差别,利用弯曲数据进行有限元仿真可以更好地描述板材在弯曲过程中的力学性能变化.

Aiming at the problem that the change in mechanical properties of sheet metal could not be accurately characterized accurately by uniaxial tensile test,a control system of sheet metal bending test device based on fuzzy proportional integral differential(PID)was designed.First,the overall design of the control system was given.Then,the electromechanical coupling simulation model of the device was established to ensure the stability of the motion process of the device,and the adaptive control method based on fuzzy PID was proposed to realize the adaptive online tuning of the parameters of PID controller during the working process of the device.Finally,the control platform of sheet metal bending test device was built,and the bending test of ultra-high strength steel DP980 was carried out.Results show that the positioning error of the platform based on the fuzzy PID adaptive control method is±0.005°,reducing the interference of axial force on the bending process of the plate.The parameters of mechanical properties of ultra-high strength steel DP980 obtained from bending test are obviously different from those obtained from tensile test,and finite element simulation using bending data can better describe the changes in mechanical properties of the plate during bending.