การควบคุมเครื่องกัดซีเอ็นซี ชนิด 3 แกน ด้วยตัวควบคุมแบบ พี ไอ ดี

Abstract

This research is about creating and designing the control system of 3 axis CNC machines, which will be used as the prototype for studies and experiment of closed-loop controller designing. The movement in 3 axis was driven by 300-watts permanent magnet DC Servo motor and 400-watts spindle motor. Each axis contains motor control set that use pulse width modulation. Under the closed-loop position control with PID controllers, which were made from computer program. The order for the position of movement was created from 2 types of movement profiles. The first one is constant acceleration-constant retardation. The second is constant acceleration-constant velocity-constant retardation. In which the value of velocity and acceleration that are under the control can be changed. From the experiment, the control of movement by the first type of profile, for X axis the best value is equal to +/-1.3mm/s2 and as for Y axis, the best value is +/-1.5 mm/s2 and for Z axis, the best value is +/-1mm/s2.The best results of the control under the second type of profile order for X axis occur when constant velocity is equal to 4 mm/s and constant acceleration is equal to +/- 1.5 mm/s2. And for Y axis,the best value is when velocity is equal to 4mm/s and acceleration is equal to +/-3mm/s2. And for Z axis, the best value is when velocity is equal to 2mm/s and acceleration is equal to +/-2 mm/s2. The velocity and acceleration were limited because the nonlinearity of inertia that has not been simulated in the mathematics model, the uncertain of friction in each axis’s structures and the speed of motor response.