Study Of High Precision Linear Servo System Parameter Identification And Compensate Control

Modern top grade numerical control machine tool has higher and higher precision demand to numerical control servo system.Adopting permanent magnet linear synchronous motor(PMLSM) direct drive is one of necessary approaches of realizing high precision.But during the period that linear system moving as to all kinds of interior and exterior cause,its parameter and exterior disturbance have large uncertainty.Owing to this uncertainty,control quality of system maybe decrease badly.In allusion to influence of mover mass variety disturbance,load resistance disturbance and friction disturbance under low speed to servo system,some studies have been done and relevant schemes has been put forward.At first,mathematical model of PMLSM is established.Simulation diagram under Matlab circumstance is built.In allusion to mover mass variety disturbance,method of disperse model reference adapt identification is adopted to estimate variety of mover mass at real time,and then according to the role using current value of identifying mover mass to amend every speed controller parameter,make servo system has good dynamic and static performance when mover mass changes.The simulation result indicates this approach make identification parameter has quick constringency speed,good real-time performance,can track input without excess,and system precision has improved greatly;In allusion to load resistance disturbance,its identification approach and compensate method is raised,make observed load resistance variety compensate proportioned to motor current control end,so as to restrain load resistance disturbance,and enhance system robustness. The simulation result indicates this scheme is effective;In allusion to nonlinear friction disturbance which can decrease servo system track performance,based on Genetic Algorithms parameter identification method is adopted to identify system friction model parameter,and compensated control to permanent magnet synchronous linear servo system is made.The simulation result indicates this control scheme make system response quickly, static precision has improved greatly,and can realize system placid run under slow speed. The studies indicate these adopted compensation measure has strong robustness to system parameter variety and friction disturbance,and it can make permanent magnet synchronous linear servo system have higher control precision,strong real-time performance and meet perfectly request of machine tool high precision process.