Analysis to Accuracy of a High-speed Mobile Platform Control System

摘要

The efficient manufacture technique involves a high-speed control of platform mobile system. A linearrnacutor is presented in this paper. The linear acutor is constructed as a linear stepper motor. However, to sustainrnboth high accuracy and high speed for the position and speed control, A single-stack computer system isrnconstructed and a special control algorithm is prescribed to controled the linear actuator continuously. In thisrnpaper, the nonlinear errors resulted from the magnetic saturation and the hysteresis is anaysis and discussed. Inrnthe view of electromagnetic propotional control, the actuator is a stage proportional magnet, because the drivingrncurrent to the linear acuator changes for a number of cycles and a series of reset points will occur as the currentrnundergoes cyclic changes. At each reset point the original starting characteristics of the system are re-established.rnA large number of reset points across the full stroke of the platform results in a significant reduction in thernnonlinear behavior. The stage control is first discussed. Experiments carried out to obtain the characteristics ofrnthe mobile platform control system. It is demonstrated that with the introduction of stage control, nonlinearities,rnsuch as saturation and hysteresis, are greatly reduced, system stiffness is increased, and the positioning accuracyrnand resolution are improved. The effect of dither due to a “digital fragment” signal is also examined and foundrnto be crucial in reducing the hysteresis and in improving the resolution accuracy.