In order to select the appropriate filtering method from the UKF and CKF for the different dimensions nonlinear
systems estimation, the two filters are analyzed and compared through the Taylor expansion of function and the numerical
stability. Due to the different dimension, the captured high-order item degree of function Taylor expansion and the numerical
stability are different to appear different filter precisions, so that the filter choice ways of different dimension are acquired.
Simulation results show the correctness of with the theoretical analysis.