Research On Variable Curvature Forming Process And Control Algorithm Of Aluminum Profile

Due to the limitation of the traditional bending forming process,the forming of a profile with complex curvature usually requires more complicated springback compensation calculation to reach the designed curvature value,and the internal stress of the profile after molding is large,and the dimensional accuracy is poor.However,in China's aviation,construction,automotive and other industries,there is a huge demand for high-precision,complex-curvature aluminum alloy profiles,but China's current variable-curvature molding technology is relatively backward and cannot meet the needs of China's manufacturing2025.In order to solve the short board of China's variable curvature forming technology,this paper studies the variable curvature forming technology from the following directions.First of all,based on the theory of plasticity and finite difference algorithm,this paper deduces two algorithms for calculating the profile trajectory in extrusion variable curvature forming.At the same time,in order to shorten the calculation time and ensure a certain trajectory calculation accuracy,based on the derived trajectory calculation algorithm,according to the influence of different parameters on the time step size,a corresponding variable time step size algorithm is designed.Based on the trajectory calculation algorithm and the difference algorithm,the speed solution algorithm of the variable curvature profile interpolation node is obtained.The resulting profile motion trajectory algorithm establishes the basis for the following model feedforward control.Secondly,based on the gradient descent algorithm,this paper proposes a trajectory optimization method for bending die motion in extrusion variable curvature molding equipment.An iterative calculation algorithm for the optimization of the trajectory of the bending die when the bending die faces profiles with different curvature radii is analyzed.And consider the optimal motion trajectory corresponding to the bending mode when the optimal motion trajectory does not meet the used power of the electrical equipment.This article also focuses on the range of molding curvature of the variable curvature molding equipment under unidirectional control.Finally,the simulation of the extrusion-curvature molding equipment was established based on the Matlab,and the parameterization of the control model was realized.It was used to simulate different control methods and fit relatively better control parameters.This subject is also based on software environment such as labview,bus technology such as Mod Bus TCP / IP,hardware platforms such as arduino,Broadcom,etc.,and has developed a control system for extrusion variable curvature molding equipment.This system can realize the control of extrusion bending equipment,Reading of related parameters and input of control model and storage and display of key data.Based on the developed system,the standard also analyzes the traditional PI control,sliding film variable structure control,and impedance control,and combines the sliding film variable structure control and model feed forward control to achieve the combined control of the system,and the sampling cycle is within 10 Hz.It lays the foundation for higher precision and more intelligent variable curvature forming control.