Experimental Evaluation of Damping Suspension Performance for Unmanned Aerial Vehicle Camera Equipment Using Combined Optical Flow and Inertial Sensor Analysis

Ensuring stabilization of imaging equipment onboard unmanned aerial vehicles is a critical factor for the quality of aerial photography and spectrometric measurements, while objective comparative assessment of the effectiveness of various damping suspensions under real flight conditions remains a methodologically challenging task. Аim of this work was an experimental evaluation of the damping suspensions for UAV payloads effectiveness using integrated analysis of IMU data and computer vision. Studies were carried out on a system based on the Matrice 300 RTK unmanned aerial vehicle and a Raspberry Pi data logger. Damping suspensions operating in compression and tension were compared with rigid mounting. Methods used for video stream analysis to determine the amplitude-frequency characteristics of the imaging system orientation angles were described. Data processing methods from the inertial measurement unit to obtain information on the dynamics of orientation angles are indicated. A method for integrated processing of camera and IMU data is disclosed, which allows combining the low-frequency accuracy of optical flow with the broad bandwidth of inertial sensor measurements. The effectiveness of different types of damping suspensions was investigated at drone flight speeds from 1 to 7 m/s. It was found that the best performance was exhibited by a suspension with silicone dampers operating in compression, which reduced the energy of vibration processes by up to 77 % in the range from 0 to 85 Hz.

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