The Research On Numeric Controlled System Based On PMAC For Abrasive Water Jet Cutting Machine

As a non-traditional machining methods, abrasive water jet have unique advantages over other non-traditional machining methods, such as non-heat-affected zone in work pieces, smaller force and widely processing range etc. Abrasive water jet has now been widely used in many industrial sectors.The mechanism of abrasive water jet cutting were studied in detail. Mathematical model of abrasive water jet machining was established. Study shows that for the brittle materials, the processing mechanism is the impact of small angle micro-cutting and inter-crystalline cracks and near-vertical angle of the plastic deformation and lntergranular cracks. Material removal process is mixed fracture of transgranular fracture and intergranular. Processing parameters on the machined surface quality has a significant influence. According to the analysis of abrasive water jet machining, the relationship between surface quality and processing parameters were given out. The surface roughness reduced while water pressure increases. The surface roughness increases while cutting speed increases. The surface roughness reduced while abrasive particle size is smaller.Through detailed analysis of the functional modules of machine, a form of numeric controlled system based on industrial personal computer (IPC) and programmable multi axis controller (PMAC) for abrasive water jet machine was designed. The mechanical and mathematical models of parts of abrasive water jet machine were established.In this paper, AC servo driven system by permanent magnet synchronous motor was designed. In the closed-loop AC servo control system, industrial computer is a higher level computer, programmable malti-axis controller is lower level computer. Therefore a precision with 0.001mm by CNC abrasive water jet machine could be realized. Based on SIMULINK simulation model of servo system for CNC abrasive water jet machine tool were built. The dynamic response of the model was analyzed. The main performance indicators of servo system were studied. Dynamic performance of the servo system was improved using digital position servo control method.