Vision-based attitude estimation and control for unmanned helicopter landing

The main challenging task for UAVs control is to find their position and orientation accurately during the flight. In this paper, we propose a new vision-based algorithm to estimate the landing attitude of unmanned helicopter (UH), using two onboard cameras. Then we design the double-loop PID controller with calculated pose parameters to stabilize the UH by analyzing the mathematical models of UH three-channel (pitch, roll and yaw). The experiments showed that the calculated real-time pose by this algorithm is accurate enough to be used in UH control, and the control method has good performance and robustness.