A Study Of The Online Cutting Force Control Technology Based On Machining Accuracy

Numerical control (NC) machining occupies an important place in themanufacturing industry. As one of the key technologies, NC machining is thebasement for manufacturing modernization, and is strategically important to developmilitary industry. Using existing NC machining equipments, machining processcontrol can increase efficiency and guarantee machining quality, which is important toimprove the machine ability of the equipments and produce great economic benefits.In the NC machining Process, complicated physical factors, such as cutting force,influence the machining safely, quality and efficiency. At present, the ordinary NCtechnology focuses on geometrical motion control only without considering the effectof Physical factors. Therefore, this article will optimize the performance of the CNCsystem by increasing the online cutting force control module on the open CNC systemand reduce the impact of the cutting forces.First, the tool deflection model in the tool coordinate system and the relationalmodel of tool deflection with machining accuracy in the local coordinate system areestablished by analyzing cutting force and characteristics of the vertical end millingcutter Milling process on a five-axis CNC machine tools. Also, the conversionrelationship model of tool deflection in the tool coordinate system to the localcoordinate system is established. This paper introduces principles and methods of theonline cutting force measurement and realizes a digital low-pass filter on the filteringprocess of cutting force. Because the cutting force is measured in the workpiececoordinate system, this article establishes the conversion relationship model of theworkpiece coordinate system to the tool coordinate system. Based on the fuzzycontrol theory and empirical formula of cutting force, the online cutting force controlstrategy of the combinations fuzzy control and predictive control are presented. Thispaper designs the online cutting force control algorithm and the overall structure ofthe software, and uses the C++language in Visual Studio2010software environmentto achieve the online cutting force control system. This system has a cutting forcedisplay, the data stored, the digital low-pass filter, the system parameter setting andcutting force control function. Finally, this paper tests filtering module of the controlsystem software of the online cutting force and cutting force control module by using the original cutting force data. The results show that the online cutting force controlsystem established in this paper has a certain ability to control.