To estimate the rotor-assembly (ESC, Motor, and Propeller) parameters (Thrust and Drag Coefficients), an experimental setup is carried out. In this experiment, the rotor is mounted on a 6-DOF torque/force sensor (see Appendix I for more technical details) that is connected to a NI Data Acquisition Card (NI DAC). Then, the DAC is connected to a PC, running SIMULINK program as an interface, to read data from DAC. The velocity of rotor is changed gradually, and in each time, the generated thrust and drag moment is measured and recorded using SIMULINK program. By using MATLAB Curve Fitting toolbox the acquired data of thrust and moment is fitted to be in the form of (2.88 and 2.89). Thus, the thrust and moment coefficients can be obtained. You can check this paper and this thesis for details.