Bime Logo

FB4 Logo

Tracking Error Transform in Parallel Kinematic Machining (2011)

Amirian, G.; Schenck, C.; Kuhfuß, B.:

Key Engineering Materials, Vol. 450 (2011), pp. 585-588, Trans Tech Publications, Switzerland


Parallel kinematic machine tools (PKM) are developed to increase dynamic parameters for high speed and high accuracy machining to gain short lead times and high productivity. One of the most important components of machine tools is the numerical controller (NC). Most NCs are organized in a cascade structure, comprising the position, velocity and current loops. PID types of servo controllers generate tracking errors in each axis. Tracking errors are a significant factor on machining accuracy, besides geometric machine errors, vibrations, temperature changes and tool errors. In this paper the contour error originated from servo tracking controller in Cartesian kinematic machine tools (CKM) and PKM are presented. The effects of the forward transformation of the tracking errors in PKM are addressed with experiment and simulation results. The servo tracking effect on trace accuracy is discussed by a Tripod mechanism. Measured radial deviations are obtained with a double ball bar.