Design and analysis of power failure detector module for control of axis runaway in CNC machines during unprecedented power failures

Abstract

The introduction of Computer numerical control (CNC) machines radically changed the manufacturing industry because of it is key advantages like high accuracy and faster production. Due to the development of technology, CNC machines are driven directly from files created by CAD software packages, so that an assembly or part can go from design to production without any intermediate paper drawing work being required. In one sense, CNC machines may be said to represent special industrial robot systems, as they are programmable to perform any kind of machining operation. Most of the manufacturing industries faces problems in position control of the vertical axis during machining on CNC machines, in the event of an unprecedented power failure. The axis slips downwards due to inertia and gravitational force acting on vertical axis of CNC machines. In case of die and mould applications, where the accuracy of jobs are comparatively very high, the damages caused due to this problem are very expensive when the material being machined is titanium or other costly materials. In order to avoid this problem it is necessary to stop the axis run away immediately, by applying the electromechanical brake connected to the axis servo motor or ball screw rod in advance. This paper is a result of a project work done on the early detection of power failure by a microcontroller-based control, so as to apply the axis brake in advance and protect the axis run away.