An adaptable CNC system based on STEP-NC and function blocks

Abstract

Superior to G-code, STEP-NC is a new data model for computer numerical control (CNC). It provides rich information for CNC machine tools. This high-level information contains feature-based data. Unlike G-code that describes 'how-to-do', STEP-NC models 'what-to-do' at the task level in terms of features and 'Workingsteps'. In the absence of a STEP-NC controller, there is a need for a system which can work with STEP-NC data and at the same time interface with the existing CNC machine tools. This paper describes such a system. This system acts like a 'front-end' for the current CNC controllers, giving these machine tools a 'Plug-and-Play' feature. The core of the system is the mapping mechanism which accepts STEP-NC data and translates it into the type of G-code that a specific controller can understand. The key to the mapping mechanism is the use of function block (IEC 61499) technology. This gives the system robustness and modularity.

Enabling cognitive manufacturing through automated on-machine measurement planning and feedback

“…The quasi-standard of rigid, hierarchical control architectures in today's industry has been unable to cope with the new challenges successfully, since the production schedules and plans are known to become ineffective after a short time on the shopfloor [1]. Established production planning and control systems are therefore vulnerable to abrupt changes and unforeseen events in production processes and do not allow a real-time computation of sophisticated decision models [2][3][4][5][6]. Furthermore, with the increased size and scope of central-planning-based manufacturing execution systems, the structural complexity of these systems is growing rapidly.…”

A framework for machining optimisation based on STEP-NC

“…The "what-to-do" information maintains its generic nature until the last moment when a Fig. 4 IDEF0 diagram for detailed design of optimisation module CAM system populates the process plan with native manufacturing information in order to generate a specific "howto-do" process plan (Wang et al 2007;Xu et al 2006;Kramer et al 2006). Generic machining tools and generic cutting tools conform to the data defined by ISO 14649 Part 111 (ISO 14649-111: 2001).…”

Reducing data loss within adaptive process chains in the context of commonly-used CAx systems

“…Furthermore, there are approaches which combine STEP-NC with function blocks. One describes the converting of STEP-NC to function blocks [29] and others use STEP-NC as the communication format to send data between two connected function blocks [31,32].…”