Flying Generator Drone Breaks Two-Hour Barrier

A world of opportunity is awaiting the drone that can fly for over 45 minutes. Here is a version that can fly 100 miles on one gallon of fuel, carrying a gallon of payload. It can hopscotch anywhere in its range and become a small electric generator. This is good news.

Flight time is one of the most annoying and brutal barriers, governed by energy-density versus weight, recharge speeds, and availability of peak power for emergency maneuvers. Curiously, a practical solution to this problem lies in 19th century technology that first appeared in an Irish submarine: an internal-combustion motor recharges the onboard batteries while the sub is surfaced, then the sub dives and runs on battery power.

Depending on the engine, the output efficiency hits its peak at a constant X thousand revolutions per minute. They’ve thought of that in this invention. There is a tiny engine on the drone that is charging the LiPO battery, and the battery makes it fly. This drone can fly 100 miles on one gallon of 87 octane. Oh, and it be a generator. This is a good thing.

The application is well thought-out, giving examples of systems and engines that may be used: “the small engine 14 can have dimensions of about 12” by 11” by 6” and a weight of about 3.5 lbs. to allow for integration in a UAV. In one example, the small engine 14 may be an HWC/Zenoah G29 RCE 3D Extreme available from Zenoah, 1-9 Minamidai Kawagoe, Saitama 350-1165, Japan […]the micro hybrid generator system 10 can provide about 1,800 watts of continuous power, 10,000 watts of instantaneous power (e.g., 6S with 16,000 mAh pulse battery) and has a 1,500 Wh/kg gasoline conversion rate. In one example, the micro hybrid generator system 10 has dimensions of about 12” by 12” by 12” and a weight of about 8 lbs.”

The Applicant has likely tested the invention, with reportable results: “the micro hybrid generator system 10 can provide a loaded (3 lb. load) flight time of up to about 2 hours 5 mins, and an unloaded flight time of about 2 hours and 35 mins. Moreover, in the event that the fuel source runs out or the small engine 14 and/or he generator motor 16 malfunctions, the micro hybrid generator system 10 can use the rechargeable battery 20 to provide enough power to allow the UAV to perform a safe landing.”

This patent application is all about a “typical conventional multi-rotor UAV includes a lithium polymer (LiPo) battery which may provide about 150 to 210 Wh/kg. This may provide a typical loaded flight time of about 15 minutes and an unloaded flight time of about 32 to 45 minutes. Advance lithium sulfur batteries may also be used which provide about 400 Wh/kg of power. In this case, the flight times are about 30 minutes in a loaded configuration.”

The present patent application couples a small motor to recharge the onboard battery: “The micro hybrid generator system of one or more embodiment of can comprise two separate power systems. A first power system included as part of the micro hybrid generator system can be a small and efficient gasoline powered engine coupled to a generator motor. In various embodiments, the first power system serves as a primary source of power of the micro hybrid generator system. A second power system, included as part of the micro hybrid generator system, can be a high energy density rechargeable battery. Together, the first power system and the second power system, combine to form a high energy continuous power source and high peak power availability for a UAV, including when a UAV performs aggressive maneuvers.”

As a cherry on top of the extended flight time, the UAV of the present invention can serve as a portable generator for remote locations. It just flies to its destination with its fuel, and can sit on the ground producing electricity. As the application mentions, “[i]n the ‘non-flight portable generator mode’, micro hybrid system 10 can divert the available power generation capability towards external one or more of loads 78, 90, 92, and/or 100 […] UAV 150 uses the power provided by micro hybrid generator system 10 to travel from an initial location to a remote location, fly, land, and then generate power at the remote location […] eliminates the need to carry both fuel and a generator to a remote location.”

The first Claim is well-written although slightly narrow. I am not an expert in the field, but is inclusion of “bridge rectifier”, limitation to AC and mention of a throttle really necessary?

Claim 1: An unmanned aerial vehicle comprising:

  • at least one rotor motor configured to drive at least one propeller to rotate, rotation of the at least one propeller generating thrust and causing the unmanned aerial vehicle to fly;
  • an electronic speed control configured to control an amount of power provided to the at least one rotor motor;
  • a micro hybrid generator system configured to provide power to the at least one rotor motor comprising:
  • a rechargeable battery configured to provide power to the at least one rotor motor;
  • a small engine configured to generate mechanical power;
  • a generator motor coupled to the small engine and configured to generate AC power using the mechanical power generated by the small engine;
  • a bridge rectifier configured to convert the AC power generated by the generator motor to DC power and provide the DC power to either or both the rechargeable battery and the at least one rotor motor;
  • an electronic control unit configured to control a throttle of the small engine based, at least in part, on a power demand of at least one load, the at least one load including the at least one rotor motor.



US Patent Application No: 20160137304

Filed (US prov): Nov. 14, 2014

Published: May 19, 2016



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