how to reduce fitting error for a model after using parameter estimation tool in simulink

after using parameter estimation app in simulink and enter the measured data and for input of a current and output of a voltage as real data and having 4 parameters to estimated them in the model. there is a large error of fitting between the 2, even i changed my initial guess and make boundry for parameters also the scale

take a look :

our entered data

simulation estimation and simulated data: