A novel external modular hardware architecture for PC-based Soft-CNC system

In recent years, there have been growing interests on the study of software-oriented computer numerical control (Soft-CNC) system which plays an important role in the field of advanced manufacturing. However, existing Soft-CNC systems have somewhat limitations in that special motion control and I/O card should be inserted into PC or needed to use the servo driver based on digital communication such as SERCOS, EtherCAT, and so on. To get a better universality, in this paper we propose a novel external modular hardware architecture for developing Soft-CNC system on general PC. The external modular hardware architecture consists of seven kinds of partial module units: main module unit, axis module unit, spindle module unit, digital I/O module unit, analog I/O module unit, MPG module unit, and MCP module unit. We present the detailed design and functions of seven kinds of particular module units, and the data communication methods are described. Also the software implementations of Soft-CNC system using the external modular hardware architecture are presented. The proposed system has implemented on three axis machine tool and verified the operating correctness of proposed architecture by experiments on path of 3D butterfly shape. The experimental result shows that the external modular hardware architecture for Soft-CNC system operates correctly.