Study On Position Control Based On Pulse Including Feedback And Feedforward

Position control system is one of the important parts of the CNC system, also called position servo system , the function of which is to control the movements of axes according to the position command from NC system, so that the axes can follow the change of the command quickly and exactly. As one of the most important parts of the NC machine tool, its performance has directly influence on the qualification of the entire machine tool such as precision, rapidity and reliability,which is determined the good or bad of the control. Therefore the introduction of the new position control algorithm has now become improve precision position control system the main method.In the thesis, based on the pulse control for the position control system, the position control algorithm including feedback and feedforward compensation was researched, and the feedback and feedforward control theory was analysised in-depth, and the forward differential control was proposed which combined the position control system based on pulse. The main contents as following:1 .An experimental CNC platform of NC embedded PC type with the structure of embedded PC and motion control card was established, The Panasonic AC servo driver and servo motor were used.2.The circuit handling with the feedback pulse was designed and the FPGAprocedures including frequency multiplier and counting was written.3.The second-order linear simplified model of position control system was established .The simulation model and the transfer function of the position control system was built with MATLAB/SIMULINK language ,and the parameters were established through a series of experiment and simulation.4.The programme of PC for experiment was written. In the thesis ,the author used the control methods including feedback and feed-forward , experiment and simulate on the response of the typical signals in the position control system, study the influence of numerical PID control arithmetic, feed-forward arithmetic and related control periods etc. to the performance of the control system. Through the testing results ,the control methods including feedback and feed-forward could improve the accuracy of the system ,the feasibility and practicality of the system introduced here come into affirmation.