Investigation into feedback control of part-fixture systems undergoing dynamic machining forces

The main focus of research in part-fixture mechanics has been in the static deformation and part constraints. Little attention has been paid to the dynamic behaviour of these systems. However, the dynamics of the system largely determines the obtained precision during the machining process. The part is modelled as a lumped mass-spring model and the clampers and locators of the fixture are modelled as springs. The fixture frame is considered to be much stiffer than the locators such that it provides zero displacement boundary conditions to the locators. In this study a hydraulic actuator is utilized to provide adaptive clamping forces. The analysis has shown that position feedback can be used to minimize unnecessary displacement of the workpiece. Additionally, a lead filter can be used to improve the steady state response.