Solar powered miniature drone
Endurance is related to the "vitality" of the UAV, and solar energy supply is one of the important ways to achieve long-term endurance of the UAV.
A research team at Beihang University in China has successfully developed a solar-powered miniature drone weighing only 4.21 grams using a new type of electrostatic motor independently developed by the university to achieve continuous flight under pure natural light. The results were published in the international academic journal Nature on July 18.
Solar powered large drones are not new, but how to use solar power to drive micro drones has been a problem in the industry. Current UAVs usually use traditional electromagnetic motors as engine components, although the current conversion rate of solar panels is low, but large uAVs can load large areas of solar panels to provide enough kinetic energy; For the micro-UAV, the electromagnetic motor increases in speed and heat after miniaturization, and the energy conversion rate decreases sharply, while the fuselage cannot bear the load of a large area of solar panels, resulting in its inability to fly.
The tiny drone has a wingspan of about 20 centimeters and is fitted with two ordinary solar cells that are less than half the size of a hand.
How does it fly?
"The key is the power system." Professor of Beihang Energy and Power Engineering College said that the primary consideration is to reduce the heat loss of the power system, so that the electric energy generated by solar cells is efficiently converted into kinetic energy. The team innovatively proposed a new electrostatic drive scheme and developed a micro-electrostatic motor with low speed, less heat and high efficiency to realize the take-off and continuous flight of the micro-aircraft under the energy supply of pure natural light.
The professor said that the reason why electrostatic motors can reduce heat is that static electricity has the characteristics of high voltage and low current, and the smaller the current, the less heat. "It's the same way static electricity works when you wear clothes in winter. The voltage of static electricity on clothes can reach thousands or even tens of thousands of volts, but because of the small charge and small current, the electrical power generated is small, and it has almost no impact on the human body." He said that the team specially developed an ultra-lightweight high-voltage power converter weighing only 1.13 grams, which increased the voltage generated by the solar cell from about 4.5 volts to 9,000 volts, creating an electrostatic system.
The solar micro-UAV can achieve long endurance flight, and after further development in the future, it is expected to be applied in emergency rescue, narrow space detection and other scenarios.
