  The paper is devoted to the accuracy improvement of robot-based milling by
using an enhanced manipulator model that takes into account both geometric and
elastostatic factors. Particular attention is paid to the model parameters
identification accuracy. In contrast to other works, the proposed approach
takes into account impact of the gravity compensator and link weights on the
manipulator elastostatic properties. In order to improve the identification
accuracy, the industry oriented performance measure is used to define optimal
measurement configurations and an enhanced partial pose measurement method is
applied for the identification of the model parameters. The advantages of the
developed approach are confirmed by experimental results that deal with the
elastostatic calibration of a heavy industrial robot used for milling. The
achieved accuracy improvement factor is about 2.4.
