Adaptive Process Control System of Fine Turning with the Use of Vibroacoustic Signal on CNC Machines

Abstract

One way to improve the quality and accuracy of machining is a method based on intervention in the process course. Adaptive control is a promising direction of process control. The creation of machines of high accuracy and rigidity, high resistance tool, the development of active control has led to the fact that the role of the dominant factors that generate processing error, were random factors and primarily such as the fluctuation of the allowance and hardness of the workpiece material, as well as the wear of the cutting tool and the condition of the equipment. The actions of these factors are the main reason that prevents the quality improvement and processing productivity. The aim of this work is to study the possibility of using the vibroacoustic signal as an information source for the structure and algorithm development of the finishing turning process adaptive control system. It is established in the work that the signal generated by the technological processing system is random when finishing turning parts from hard-to-process materials. As an information signal for the technological processing system diagnosis, the most promising will be the use of an acoustic signal that directly accompanies the process of parts mechanical processing. Experimental dependences of roughness parameters and vibration signal parameters on cutting conditions (tool feed, spindle speed) and tool wear are presented. The calculations carried out in the work showed that there is a correlation between the vibration signal parameters and the parts surface roughness parameters. The correlation coefficient between these functions reached 0.75…0.85. Therefore, by controlling the level of the vibroacoustic signal, it is possible to estimate the output parameters of the machining process. On the basis of the conducted researches the adaptive control system structure variant is offered, the information source for which is the vibrations Converter occurring in technological system.