The Research On Electrical Control System Based On PMAC For CNC Water-jet Machine

The abrasive waterjet technology in the three-dimensional processing is still at early stage. It has broad application prospects and higher commercial value. Therefore design of computer numeric controlled (CNC) abrasive waterjet machine tools was put forward. The design of electrical control system was carried out and it is applicable to three-dimensional processing.In order to meet the requirements of turning, milling, drilling, grinding and other function of CNC abrasive waterjet machine tool, the rotation axis A and abrasive flow rate control axis B is combined to form five-axis machine tool. Thereafter control of the parameters on abrasive flow rate, machine tool feed rate, water pressure and target distance which affects the abrasive water jet machining could be realized.Based on the industrial personal computer (IPC) and programmable multi-axis controller (PMAC), hardware of open CNC system is designed. The feed servo control system uses semi-closed-loop. The spindle servo system uses AC variable frequency control. And abrasive flow rate control devices uses pulse width modulation (PWM) speed control.The testing and debugging of electrical system on test platform was carried out. The PID parameter tuning can improve system stability on PMAC. And through selection of interpolation of data sampling method in PMAC, the precision of hardware interpolation can be improved. An error compensation and speed control for the features abrasive waterjet soft tool were proposed.The turning, milling, cutting and other experiments on HJ300-0503 machine were made. It shows that compensation control of machining accuracy can significantly improve machining quality. The cutting depth of abrasive waterjet is reduced with the decrease of pressure and increase of feed speed. It proved that the three-dimensional processing can be done under the control of the corresponding parameters. It verifies that abrasive waterjet turning of materials is feasible.Therefore development of three-dimensional CNC abrasive waterjet machine tool will be a wide application prospect.