Multi-mechanism Cooperative Force Planning Of Variable Cross Section Roll-forming Machine

With the rapid development of the automotive industry,the demand for variable section roll-forming machines for automotive shell processing is increasing.At present,the research on the mechanics of variable cross section roll-forming machines is mainly based on system dynamics research or software simulation.Few studies are based on the cooperative force planning of variable cross section roll-forming machines.This paper studies the problem of force imbalance in the process of variable section rollforming machine,and solves the collaborative force planning research from three aspects of dynamic modeling,internal force planning and sliding mode variable structure control to reach the variable section roll forming machine.The purpose of stable processing and accurate trajectory.Fundamental research on single-pass roll-forming machine with variable section.Based on the schematic diagram of the rolling mill's equivalent mechanism,the kinematics model of the rolling mill's left arm with the D-H method,and the simple space trajectory planning of the mechanical arm joints are the basis of dynamics research.Then the dynamic model of the rolling mill manipulator is derived through Lagrange dynamics,and the formulas for solving the moments of each joint are obtained.Finally,simulation examples are used to verify the kinematics and dynamics models.The internal force planning of the imbalance of the plate force during the processing of the variable section roll-forming machine is first studied.First,the working state of the rolling mill is divided into two operating modes,no-load and fullload,and the system dynamic equation including the plate is deduced..Then the mathematical expressions of the speed and force of the rolling mill joint space,operation space and sheet forming space are established.Based on the coupling problem of the dual-arm mechanical equation of a single-pass mill,three mainstream optimization methods are used to solve the force on the plate at the end of the mill operation.Finally,the internal force planning is realized to solve the problem of imbalance of the plate stress.Aiming at the unpredictable problem that the stress on the rolling mill when processing the plate is time-varying,a sliding mode variable structure control design for the rolling mill manipulator is carried out,in which the control rate is derived in detail and the stability of the system is analyzed.Sliding mode variable structure control can make the nonlinear system stable and has strong robustness.Finally,the trajectory tracking effect of the sliding-mode controller is obtained through a numerical simulation.This control study provides a basis for in-depth control research and provides a certain guiding role for practical engineering applications.