An Autopilot for Steering Flying Wind Turbines
The idea of using kites as an alternative to wind turbines has been gaining ground amidst the scientific community, as winds are much stronger and consistent above a 1,000-meter altitude than on the ground. At the Swiss Federal Institute of Technology in Lausanne, Ph.D. student Sean Costello has developed an autopilot system to control and optimize a kite's movement so as to obtain the best possible electricity production. The kite's sail acts as a wind turbine blade. As it offers resistance to the wind, it creates a mechanical tension on the kite's restraining cable. It is then possible to use the cable's winding and unwinding movements to drive an electric generator that can be placed either onboard or on the ground. "The stronger the cable tension is, the higher the energy production capacity, said the researcher. The autopilot that we have developed is able to find, in any given situation, the most efficient way to control the wing so that it moves as quickly as possible and generates a maximum tension in the cable. In general, the kite's trajectory will have the shape of an 8. Since some flight paths turn out more successful than others, the autopilot will determine which one is best in each situation," says Costello.
Transcript
00:00:06 kites are an excellent way of extracting energy from the wind you can think of a kite as a wind turbine without the tower so without the structure and by removing the structure uh the blades can fly through the sky uh and they can also reach much higher altitudes than you'll be able to reach with a wind turbine the way it works is that the wind hits the wing and generates large aerodynamic
00:00:29 forces and these are mitted to the ground directly using a tedar if you want to generate electricity you wind this tedar around the generator and then you slowly unwind the the the Reel and this generates electricity so we're making an autopilot for KS on the one hand it's an advantage that the kite is free but on the other
00:00:52 hand uh it means that you constantly need to be controlling the kite if you don't steer it all the time it'll crash into the ground very quickly and a matter of seconds obviously you can't have a person constantly steering the cut 24 hours a day so that's why you need an autopilot so what we have is a motor which controls the steering lines that allows us to go left or right then
00:01:13 we have sensors uh which allow us to obtain the position the velocity and the orientation of the kite at all times we're measuring the wind and we also measure the tension in the in the tedar and all of this information is fed into the the autopilot uh which makes a decision in a split second based on that information and it decides how it's going to steer
00:01:37 the kite a basic autopilot will keep the kite in the air our aim is for the autopilot to also maximize the tther tension