Sd. Jones et Ag. Ulsoy, AN OPTIMIZATION STRATEGY FOR MAXIMIZING COORDINATE MEASURING MACHINE PRODUCTIVITY .2. PROBLEM FORMULATION, SOLUTION, AND EXPERIMENTAL RESULTS, Journal of engineering for industry, 117(4), 1995, pp. 610-618
In this, the second of two papers focused on optimizing CMM productivi
ty, a strategy is presented for obtaining operating speeds that maximi
ze CMM throughput. The strategy involves posing the objective and cons
traints in terms of a nonlinear programming problem. The objective is
to minimize measuring time, and constraints are on measurement quality
, available motor power and other machine specific characteristics. So
lutions to various measurement scenarios are given, computed with a ge
neralized conjugate gradient method that uses a golden section accepta
ble search method. Also, a sensitivity study is presented that utilize
s the optimization strategy to determine how change to a CMM's design
will affect overall productivity. In the final section, experimental r
esults utilizing the optimally computed trajectories for both single a
xis and multiple axis motion are given. In addition, an example is pre
sented to demonstrate the implementation of the optimization strategy
in an actual measuring application. In the example, a connecting-rod i
s measured at three speeds: the machine's default speed, a speed const
rained by available motor power, and the optimized speed (constrained
additionally by measurement quality). The experiment demonstrates a 27
percent reduction in time for the optimized speed compared to the def
ault speed using the Bartlett test for comparing variances in the dime
nsional data obtained.