Research On Control Strategy Of Forming Process Of Full Servo Four Roller Bending Machine

The four-roller plate rolling machine is suitable for bending and forming of steel plates and other materials.It can roll round,curved and conical workpieces within a certain range,and has the function of pre-bending the end of the metal plate.There are few straight edges and high efficiency.And can roughly level the board on the machine.Permanent magnet synchronous motor is a synchronous motor that generates a synchronous rotating magnetic field by permanent magnet excitation.It is characterized by high working efficiency,small torque ripple,good dynamic response,and wide speed range.Therefore,the full-servo four-roller rolling machine driven by the motor has the characteristics of high rolling accuracy and more accurate positioning accuracy,which has become a direction of the development of the rolling machine.According to the rolling characteristics and process requirements of the full servo plate rolling machine,the research content of this article mainly includes the following three aspects:(1)Analyze the four-roller plate rolling machine's coil forming process,familiar with the main steps of preparation,centering,pre-bending,coil forming,and jointing during the coiling process,and clarify the control objects and process flow.Understand the structure and working principle of the permanent magnet synchronous motor,analyze the structure characteristics of the rotor of the motor,be familiar with the basic principle of the coordinate transformation of the permanent magnet synchronous motor,give the mathematical model of the permanent magnet synchronous motor in different coordinate systems,and derive the permanent magnet synchronous motor Motor mathematical model.(2)Compared with the conventional PI-controlled permanent magnet synchronous motor,the speed loop of the permanent magnet synchronous motor is improved to improve the robustness problem.The PI controller is mainly optimized through the bat algorithm and BP neuralnetwork.Because the PI controller parameters in the conventional method are not the global optimal solution,the optimal solution is searched through the bat algorithm to improve its control parameters;BP neural network control is adopted.When the operating state of the system changes,the neural network is used to automatically Adjust the parameters of the PI controller,and optimize the PI control parameters through self-learning and adjustment of the weighting coefficients.After the algorithm is improved,high-precision tracking of the position of the metal sheet can be achieved.(3)In the rolling process of metal sheet,the radius of curvature of the workpiece is the most important parameter,which directly affects the coiled material ratio.Therefore,online detection of the radius of curvature of the metal sheet is particularly important.Using a laser distance measuring device,combined with Siemens 300 series PLC,an online detection device system for the radius of curvature of metal sheet was designed and developed.Through the online detection of the radius of curvature of the metal sheet,the closed-loop control of the rolling process is achieved,which ensures the accuracy of the rolling of the metal sheet and the yield rate.Through the research of this subject,it is verified that after the optimization of the speed control of the all-servo four-roller rolling machine,combined with the curvature radius detection system,it meets the high-precision rolling requirements of metal plates and improves the roll forming pass rate.