Anyone who has ever flown a quadcopter for business, scientific, military purposes, pleasure or indeed any application will know that the wind is the enemy of stable flight of these unmanned aircraft. These aircraft are often used to take aerial photographs or record video footage from the air for a wide variety of reasons. However, no amount of onboard camera stabilisation can overcome the buffeting of sudden gusts of wind or random turbulence. Moreover, strong gusts can knock a quadcopter out of the sky.
Now, Long Zhao of the School of Automation Science and Electrical Engineering, at Beihang University, China, and Zefang He and Yulong Zeng in the School of Automation Science and Electrical Engineering there have devised a new robust control system for these machines that uses the device’s integral backstepping controller to adjust the aircraft’s attitude in flight and overcome the impact of strong gusts on flight stability.
Quadcopter, also known as quadrotor helicopters or quadrotors have become rather popular for a wide range of applications including aerial photography and videography amateur, professional and media, civil and military surveillance and mapping, scientific experiments, for hobby and tourism applications, search and rescue and much more. In general, these aircraft use two pairs of identical fixed pitched propellers – two that rotate clockwise and a pair that rotate counter-clockwise. They are controlled independently by the device’s software to achieve altitude, attitude, direction, speed and turning control.
The team’s improved system for control of a quadcopter in windy conditions is now in the testing stages and could be implemented in software upgrades in future models.
Zhao, L., He, Z. and Zeng, Y. (2016) ‘Hierarchy robust control for unmanned quadrotor helicopter without linear velocity measurement‘, Int. J. Automation and Logistics, Vol. 2, No. 3, pp.252-265.