Abstract—Energy consumption is the main cost item in the marble cutting process by using segmented circular sawblade. Therefore, there are many benefits to take measures for reducing the energy consumption. The aim of this study is to reduce electricity consumption in marble cutting process by using control methods. In the study, cutting experiments were performed with a fully computer controlled test rig for three natural rocks (Burdur beige and Usak green marbles and Afyon travertine). The experiments were carried out on two modes (manual and automatic). In the experiments, travel speed is kept fixed in manual mode as usual in industry. In the experiments performed on automatic mode, travel speed is controlled by a controller embedded closed control loop during the cutting process. In addition other machine parameters such as sawblade rotation speed, cutting depth, flowing speed of cooling water are kept fixed in all experiments. In designed control systems, floating and PID controllers are used to control travel speed. Obtained results are showed that, if the travel speed is controlled during cutting process, energy saving can be provided in both of two controllers for all of three rocks. Index Terms—Energy saving, marble cutting, applied control, floating and PID controller. I. INTRODUCTION Afyon is one of the most important marble supplier cities of the world and Turkey with its plenty of marble mines and factories. For separating the block marbles taken from mine to plaques, block cutting machines segmented diamond circular sawblade are used. There exist many parameters effecting the cutting operation in circular sawblade cutting process. These are separated two parts; first one is machine parameters (sawblade rotation speed, travel speed, cutting depth, flowing speed of cooling water, cutting mode ‘down or up-cutting’, metallurgic and mechanic features of diamond sockets, sawblade thickness), second one is rock parameters (mineralogical and physical-mechanical features) [1, 2, 6-8]. Many studies have been realized to examine the effects of the said parameters [3-5]. Specific energy is defined as energy consumed per unit volume and it can be used to monitor efficiency of marble cutting process. The sawblade rotation and travel speeds have significant effects on specific energy. In studies, it is observed that the travel speed effect is more than the sawblade rotation speed effect [4, 7]. In industry, block cutting machines called as Manuscript received July 19, 2012, revised September 10, 2012. Said Mahmut Çınar and Hasan Çimen are with the Electrical Engineering Dept., Afyon Kocatepe University, Afyon/Turkey (e-mail: smcinar@gmail.com; hcimen@aku.edu.tr). Ahmet Zengin is with the Computer Engineering Dept, Sakarya University, 54187 Sakarya/ Turkey (e-mail: azengin@sakarya.edu.tr). stripper-trimmer (ST) are widely used for separating block marble to plaques. In the ST machines, sawblade rotation speed is usually adjusted with wheel-belt systems and it is fixed during cutting process. Travel speed is changed by machine operator and it is commonly held on fixed value. However, marble is not homogenous material and it can contain different hardness regions. Because of these fixed parameters, efficiency decreases in cutting process. For adjusting sawblade rotation speed, motor drivers were recently used in ST machines, but drivers are not widely used. On the other hand, for changing travel speed, drivers are nearly used in whole of ST machines. In the circular cutting process, if travel speed is controlled by a controller embedded in closed control loop, energy saving is possible. In a study travel speed has been controlled by floating controller and 10% energy saving is carried out [8]. This study is showed that if travel speed is controlled by advanced controllers such as PID and fuzzy logic, more energy saving can be obtained. In presented study, we examine floating and PID controllers embedded in closed control loop. Three natural rocks (Burdur beige marble, Usak green marble and Afyon travertine) are used as work piece for sawing experiments. Cutting experiments were performed with a fully computer controlled test rig designed just as ST machine [4, 6]. An interface which provides control of the test rig was designed with National Instrument (NI) LabVIEW programming language which is widely used for academic and industrial applications [9]. In addition NI PID toolset was used for designing PID controller. In below, firstly, control loop and controllers are presented. Then, results obtained from experiments are given and discussed. II. CONTROL LOOP AND CONTROLLERS In the marble processing industry, the specific energy can be used to monitor efficiency of cutting process and for predicting required energy. Sawblade rotation speed, travel speed, cutting depth, flowing speed of cooling water, cutting mod, metallurgic and mechanic features of diamond sockets, sawblade thickness, and marble features are directly connected with the specific energy. Travel speed effect is the most within these parameters [4, 7]. There is adverse proportion between travel speed and specific energy. In Fig. 1, an experimental result which is performed for Usak green marble is seen. This experiment is started with 0,7m/min. travel speed and after the sawblade entering completely within the marble, travel speed is gradually increased. With increase in travel speed, decreasing is showed in specific energy. The specific energy Control Applications for Energy Saving in Marble Machining Process S. M. Çınar, H. Çimen, and A. Zengin International Journal of Machine Learning and Computing, Vol. 2, No. 5, October 2012 695 10.7763/IJMLC.2012.V2.217