Development Of An Open-CNC Lathe System For Application Of Teaching

With the rapid progress of the manufacturing and the popular application of the NC equipment,more and more versatile talents of mechatronics are needed in china. At present,the equipment usedfor the traditional in most universities and training institutions are closed CNC systems. The CNCtraining for the technical personnel is limited to CAD/CAM and operation aspects of CNC machine.Some trouble is made when students learn the principles of numerical control technology，electricalstructure CNC system and CNC system control method. Meanwhile, the students’ creative thinkingand innovative experiments are limited by the traditional closed CNC systems. All of these cramp thecultivating of NC talents.The subject is based on the concept of the open numerical system.The teaching platform of CNClathe was developed that can be used for training, curriculum-design and innovating experiment of theCNC system. The hardware system is based on the motion controller of googoltech’s GTS series andunder the control of NC inserting PC system. It can realize the drive of spindle motor and steppermotor. The control of motion controlling cards, the pattern of servo-motor motion, NC decoding,circular interpolation, NURBS curve fitting and simulation are ensured in the software system. TheCNC system highlights the idea of modularization design.Training module, curriculum-design module and innovating experiment module are realized inthis teaching platform of CNC lathe. In the NC curriculum-design module, The principle of point bypoint comparison interpolation and DDA interpolation method are studied, and these two interpolationprocedures and the decoding cyclic of NC codes are developed.The NURBS curve fitting method withthe same step and the NURBS curve based on the control of contour error are focused on in the CNCinnovating experiment module. Finally,Two methods are developed,and some conclusions are got bysimulation.