Lin Ching-Fuh, Lin Ta-Jung, Liao Wei-Sheng, Lan Hsiang, Lin Jiun-Yu, Chiu Chi-Han, Danner Aaron
Graduate Institute of Photonics and Optoelectronics Graduate Institute of Electronics Engineering Department of Electrical Engineering Innovative Photonics Advanced Research Center National Taiwan University 1, Sec. 4, Roosevelt Road Taipei 10617 Taiwan.
Taipei Municipal Jianguo High School No. 56, Nanhai Road Taipei 10066 Taiwan.
Adv Sci (Weinh). 2020 Aug 19;7(20):2001497. doi: 10.1002/advs.202001497. eCollection 2020 Oct.
Sunlight energy is potentially excellent for small drones, which can often operate during daylight hours and fly high enough to avoid cloud blockade. However, the best solar cells provide limited power, compared to conventional power sources, making their use for aerial vehicles difficult to realize, especially in rotorcraft where significant lift ordinarily generated by a wing is already sacrificed for the ability to hover. In recent years, advances in materials (use of carbon-fiber components, improvement in specific solar cells and motors) have finally brought solar rotorcraft within reach. Here, the application is explored through a concise mathematical model of solar rotorcraft based on the limits of solar power generation and motor power consumption. Multiple solar quadcopters based on this model with majority solar power are described. One of them has achieved an outdoor airtime over 3 hours, 48 times longer than it can last on just battery alone with the solar cells carried as dead weight and representing a significant prolongation of drone operation. Solar-power fluctuations during long flight and their interaction with power requirements are experimentally characterized. The general conclusion is that solar cells have reached high enough efficiencies and can outperform batteries under the right conditions for quadcopters.
太阳能对小型无人机来说具有潜在的巨大优势，这类无人机通常可在白天飞行，且飞行高度足以避免云层遮挡。然而，与传统电源相比，目前最好的太阳能电池提供的电力有限，这使得太阳能在飞行器上的应用难以实现，尤其是在旋翼飞行器中，为了实现悬停功能，通常需要牺牲机翼产生的显著升力。近年来，材料方面的进步（如使用碳纤维部件、改进特定太阳能电池和电机）终于使太阳能旋翼飞行器成为可能。在此，通过一个基于太阳能发电和电机功耗限制的太阳能旋翼飞行器简明数学模型来探索其应用。文中描述了多个基于该模型的以太阳能为主的太阳能四轴飞行器。其中一个在户外的飞行时间超过了3小时，若仅靠电池供电，在携带作为额外重量的太阳能电池时，其续航时间仅为该时长的1/48，这表明太阳能显著延长了无人机的运行时间。文中通过实验对长时间飞行过程中的太阳能波动及其与电力需求之间的相互作用进行了表征。总体结论是，太阳能电池已具备足够高的效率，在合适的条件下，其性能可超越四轴飞行器的电池。
