Abstract
This paper proposes a control method for a helicopter connected to a station on the ground with power supply and signal cables. Although the helicopter has virtually unlimited flight time because of the power supply from the station, the cable applies an extra load to the helicopter. The static cable tension exerted on the helicopter is estimated on the assumption that the cable can be considered to be a catenary. We obtain the optimum cable length for each helicopter position, which minimizes the helicopter thrust needed to balance the cable tension and gravity force on the helicopter. The energy loss due to the cable load is minimized by reeling the cable in or out to maintain the optimum length, according to the helicopter position. Experiments illustrate validity of the analysis.
