Study of the X axis error positioning in the function of the machining tool temperature

Author(s)

Cláudia Hespanholo Nascimento

• Document type: Doctoral Thesis
• Press: São Carlos.
• Institution: Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD)
• Defense date: 2015-08-07

Examining board members

Reginaldo Teixeira Coelho; Patrícia Alves Barbosa; Sérgio Henrique Evangelista; Maria Célia Oliveira; Alessandro Roger Rodrigues

• Advisor: Reginaldo Teixeira Coelho

Abstract

In today\'s manufacturing industry, companies stand out if they\'re able to meet a high production demand efficiently and with quality products. During manufacturing there are several sources of error that can affect the accuracy of the machining process. Thus, it becomes important to better understand these errors to allow correction techniques to be implemented into the numerical control of the machine tool (MT) and thus improve process accuracy. In this context, the main goal of this work is to develop a method for correcting positioning errors along the X axis taking into consideration the variation in temperature, measured experimentally in specific points of the MT. First we conducted a survey of experimental positioning errors along the X axis of the MT in three different working conditions and simultaneously collecting temperature variation data. Data were treated and then synthesized using the methodology of homogeneous transformation matrices, where it was possible to store all positioning errors related to the trajectory of the board of the MT along the X axis. The elements of the matrix resulting from the homogeneous transformation are used as input data for the multiple linear regression analysis by the methods of least squares, which correlates the temperature variables with the positioning errors. As a result, linear equations obtained from the regression analysis method generates predicted values for the positioning errors which are used to correct this errors. These equations require low computer processing and therefore can be further implemented into the numerical control of the MT to correct positioning errors due to thermal deformation. The final results showed that 60 µm errors were reduced to 10 µm. It was noted the importance of synthesizing the positioning errors in homogeneous transformation matrices to apply them to the regression method. (AU)

• FAPESP's process: 10/19203-0 - Study of Dimensional Deviations in Machined Parts Caused by Heating
• Grantee: Cláudia Hespanholo Nascimento
• Support Opportunities: Scholarships in Brazil - Doctorate