DEVELOPMENT AND IMPLEMENTATION OF A DIGITAL CONTROL SUBROUTINE FOR IMPROVING MACHINING ACCURACY IN CNC MILLING MACHINES

Abstract

This study presents the development and implementation of a digital control subroutine designed to improve machining accuracy in CNC milling machines. The proposed approach integrates adaptive digital control principles into the CNC machining process by continuously monitoring machining parameters and compensating for dimensional deviations caused by tool wear, thermal deformation, vibration, and geometric errors. A conceptual evaluation was conducted by comparing machining performance before and after the implementation of the proposed subroutine using four key indicators: coordinate error, dimensional deviation, surface roughness, and machining time. The obtained results demonstrate that the adaptive compensation mechanism significantly enhances machining precision, improves surface quality, and increases production efficiency. The proposed digital control subroutine provides an effective solution for implementing intelligent CNC machining systems within the framework of Industry 4.0 and Digital Twin technologies.

The research employed a comprehensive methodological approach consisting of a scientific literature review, comparative analysis, conceptual system design, mathematical modeling, and performance evaluation. The effectiveness of the proposed solution was assessed by comparing machining performance before and after implementation using coordinate error, dimensional deviation, surface roughness (Ra), and machining time as evaluation criteria. The percentage improvement for each indicator was calculated using comparative performance analysis.

The scientific novelty of this research lies in the development of a digital control subroutine capable of automatically compensating machining errors in CNC milling operations through adaptive real-time parameter adjustment. Unlike conventional CNC programs operating with fixed machining parameters, the proposed approach dynamically responds to changes caused by thermal deformation, tool wear, vibration, and geometric inaccuracies. The integration of adaptive compensation principles with Industry 4.0 and Digital Twin technologies provides an effective framework for improving machining accuracy and process stability in modern CNC manufacturing systems.

The proposed digital control subroutine has practical significance for modern manufacturing industries requiring high-precision machining, including aerospace, automotive, medical, and precision engineering. Its implementation can substantially reduce machining errors, improve surface quality, minimize material waste, decrease manual intervention, and increase production efficiency. The proposed approach can be integrated into existing CNC systems without significant modifications and supports the implementation of intelligent manufacturing solutions based on Industry 4.0 technologies, contributing to higher product quality and lower manufacturing costs.

The conceptual evaluation demonstrated that the implementation of the proposed digital control subroutine significantly improved all evaluated machining performance indicators. Coordinate error decreased from 0.0166 mm to 0.0065 mm, representing a 60.8% improvement, while dimensional deviation was reduced by 60.0%. Surface roughness (Ra) improved from 1.80 μm to 1.12 μm, corresponding to a 37.8% reduction, and machining time decreased from 25.4 min to 23.1 min, resulting in a 9.1% improvement. These findings confirm that adaptive digital compensation enhances machining precision, process stability, and production efficiency, supporting the adoption of intelligent CNC manufacturing technologies in advanced industrial environments.