Machinery-electric-hydraulic Coupling Characteristics Analysis And Vibration Control Of Mill Screw Down System

Mill Screw down system which mainly include roll, frame, hydraulic cylinder, control device, sensor and other auxiliary equipment is a typical complex Machinery-electric-hydraulic coupling system.It is complex mechanical masses structure with elastic force connection, which will be limited by manufacturing processes and materials mill machinery and be affected by structural changes, external disturbances, non-modeled dynamics and other factors. When the mill is motivated, the stability of the system will be a sharp decline. Electro-hydraulic coupling vibration will occur in the course of the work, which could affects the production efficiency and product quality, but serious damage to the device, and even endanger their personal safety.First, the paper reviews the mechanical and electrical hydraulic coupling system’s modeling, control, coupled vibration and vibration suppression of mills in the field of domestic and foreign. It account of the progress of such studies and analyzes the problems of research measures, improving modeling and simulation methods for improving the accuracy of the mill electro-hydraulic system analysis has an important role in guiding. On this basis, we proposed the use of multi-platform joint modeling and simulation methods, and implement the integration the coupled vibration suppression strategy in convergence platform, a new method for suppressing the vibration are provided.Secondly, we study the mechanism and electro-hydraulic vibration theory,establish mechanical, hydraulic and control systems mathematical model of themill Screw down system. Building multi-DOF spring mass mathematical model of roll, racks and hydraulic cylinder etc.Then create hydraulic components’ transfer function model of hydraulic cylinders, piston rods and hydraulic valve.And fulfill eight degrees of freedom mathematical model of the entire hydraulic system and mechanical structure. Build the transfer function model of control link and sensors. and finally fulfill the establishment of mill Screw down system model with machinery-electric-hydraulic coupling.In order simulate machinery-electric-hydraulic coupling features of mill Screw down system. The modeling scheme of three joint modeling platform is used to establish multi-platform virtual prototype. Use ADAMS to build a mill Screw down system with rolls, bearings, arch frame, cylinder and other mechanical device, and connect them by adding connections deputy and the driver. Use AMESim to build a system of hydraulic control section with hydraulic cylinder, hydraulic valve and load modules by libraries of the software.Use Simulink to build a control system model, which make use of the roll displacement amount feedback control, and deal with the input signal with integral and proportional. Three modeling software are used to complete the establishment of mill Screw down system virtual prototype.Firstly ADAMS and AMESim co-simulation is set up. When ADAMS as the primary software, we can model and simulate parameters of mechanical system in the frequency domain. When AMESim as the primary software, we can model and simulate parameters in the time domain.Observate the parameters simulation running by simulation animation and curve. Then Simulink and AMESim co-simulation is set up for parameters of kinematics simulation.Finally, on the basis of the foregoing, three-platform co-simulation of mill Screw down system is used to analysis. By this co-simulation, advantages of each platform has been fully exploited,and the simulation results obtained is more in line with the actual working condition.Considering the control of machinery-electric-hydraulic coupling, this article firstly proposed the integral separation control algorithm. Cut off the integral action when the integration value reaches the set threshold to address the response phase due to an excessive accumulation of points overshoot. And the overshoot suppression method is validated at a joint simulation platform.Considering machinery-electric-hydraulic coupling caused by the external disturbances, designing PI control model with disturbance observer, the controller is proved to be Effectiv rejection of external disturbances, and studied the method of low-pass filtering for inhibiting the constant interference and random vibration. Design of the control model with a band-stop filter, to filter the control current signal. Filter out the interference signal frequencies which is near the natural frequency of the system to achieve the purpose of eliminating coupling resonance. These two types of control methods from different angles can eliminate the impact for system stability and control accuracy of coupling vibration. Co-simulation shows that the virtual prototype can be more accurately simulate actual working conditions, verify its effectiveness by suppressing coupled vibration simulation.