If a tether, attached to a kite on the ground, is retracted at the rate of 5 to 8 m/s, this is equivalent to a wind speed of 5 to 8 m/s acting on the kite and it will launch. In systems such as Daisy, MAR3 and Kitewinder, it is only necessary to retract the tether, which is attached to the lifter kite and not the whole device which remains on the ground until the kite is elevated to a height where it can lift the device. I have thought of an idea of a removable wind/unwind winch, which could be used to serve this purpose. This winch is removed from the system during normal operation. In order for this to work, we require the tether to be a loop so that it can be wound up from both sides as shown in the attached sketch:
At the beginning of the launch, the kite is lying flat on the ground. The leading edge of the kite must be raised 1 to 2 meters in order to catch the wind when the winch is activated. This could be achieved by using a simpler version of a lever arm device:
As the kite rises, the elevation and the angle of the winch must be modified to ensure that the winch is in line with the tether. For autonomous operation, we need to know either the slope of the tether or the altitude of the kite, in order to know when to stop the retraction. The winch is then slowly unwound, maintaining the same tether slope/altitude. When the winch is completely unwound, it can be removed from the system. If the winch is mounted on a vehicle, then this single vehicle can be used to launch kites in a kite farm, using a self driving program.
