Summary: | 碩士 === 國立交通大學 === 機械工程系所 === 104 === Unmanned aerial vehicles (UAV) have comprehensive applications, including military and civil ones. Now people start to think applying UAVs on serious tasks such as aerial photography, surveillance and logistics if UAVs own endurance and the capacity to lift payload. This article proposes two optimum designs. One is to determine the battery’s weight, capacity and the most efficient working power for motors. By comprehensively considering motors’ thrust-power curve, self-weight, and the specific energy of the battery, largest endurance and/or payload capacity can be achieved. Analytic, simulation, and experimental results show this optimum design method is valid.
Moreover, a kite-like UAV is leashed by a taut tether, which supplies electric power from the ground generator or battery including DC and AC systems. Although working range is restricted, the flight time is extended significantly. In DC systems, a payload model of kite-like UAV is developed by measuring electrical and mechanical characteristics of the UAV’s propulsion unit. There exits an optimum electric cable selection to achieve maximum payload capacity, largest flying range, or highest flying altitude. Simulation results and experiment indicate the proper electric cable selection is crucial for kite-like UAV. In AC systems, an AC/DC power supply is carried by UAVs. With the same power transmission, the current can be decreased by using higher voltage source. Therefore, AC kite-like UAVs can use thinner and lighter electric cable. Simulation results and experiment indicate kite-like AC system UAV can reach at most 79 meters high without carrying payload for FreeX with 22 AWG cable.
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