DEVELOPMENT AND PERFORMANCE EVALUATION OF A MULTI- SENSING RIG FOR ACQUISITION OF SELECTED MACHINING PROCESS SIGNALS

Abstract

This research achieved a multi-sensing rig for acquisition of tool-tip workpiece temperature, machine vibration and current signals during mechanical machining operation. The critical process parameters important for machining process condition monitoring were identified and the ranges of such parameters with respect to mechanical machining operation were established. Subsequently, the architecture of the multi sensing rig was developed. The device architecture integrated a vibrometer, an infrared pyrometer and a hall sensor for sensing and acquisition of the machining process vibration signal, the tool-tip workpiece temperature and the machine tool motor current signal, respectively. Appropriate holders were developed for holding the temperature and vibration sensors during machining operation. Printed circuit board was produced and used to house the components of the device. The processing unit was implemented using ATMEGA microcontroller. Evaluation of the developed rig was carried out by conducting machining operation on a lathe machine with the rig connected and positioned for signals acquisition. The Uni-T Clamp meter and X16-4 Accelerometer were simultaneously attached as a control for acquiring the same signals. After the experiments, the signals collected using the developed multisensing rig was compared with those collected by the standard equipment. Results show that the average error Ea between the standard values and actual values obtained from the rig for temperature, current and vibration are 0.01333, 0.00746, and 0.0600, respectively. The study, therefore, established that the rig produced can be used to measure the machine vibration, tool-tip workpiece temperature and current signals during machining process.