Problems of Objective Function of Error Square Sum in Parameter Calibration

The objective function provides the most important information for parameter estimation.Parameter estimation mostly based on objective function of error square sum,we found that there are some problems,such as different samples corresponding to different local extremum,unreasonable information provided by different combination of the samples,even wrong information of parameter estimation.So,some suggestions of selecting objective function are put forward,which has important guiding significance for improving precision and effect of parameter estimation.