Wind Tunnel Free Flight Model Attitude Determination Based on Non-contact IR Optical Measurement

Model position and attitude measurement is one of the key techniques for wind tunnel free flight test. The state-of-the-art model attitude is determined by a wind vane sensor mounted near the nose of the model, angular sensors or attitude and heading reference system located in the model. However, the large wind vane sensor will influence the flow distribution of the model surface, which increases the difficulty of system modelling and identification. The inner sensors occupy the limited space in the model, making it more difficult to design model and inertia similarity match. This paper proposes a solution using OptiTrack system mainly applied in motion capture for model position and attitude based on wind tunnel free flight reality. Static test and Φ3.2 m wind tunnel dynamic test results show that the static position measurement accuracy is better than 0.07 mm and angular accuracy is better than 0.05°. Dynamic tests indicate the good following performance of the system, meeting the no less than 100 Hz requirement of free flight test data update.