Small scale, lightweight, and personal aircraft have been described. For example, some have imagined small aircraft used routinely for personal transportation, such as to get to and from work or school, and/or for entertainment.
Unlike unmanned aircraft, such as drones, occupant safety is a significant concern in the case of a manned aircraft. In addition, the ability to store and/or transport a personal aircraft may become a design consideration. For example, a personal aircraft may need to be transported by ground, e.g., in a trailer or on a truck bed, to be taken to a location from which the aircraft can safely take off and land.
Various embodiments of the invention are disclosed in the following detailed description and the accompanying drawings.
The invention can be implemented in numerous ways, including as a process; an apparatus; a system; a composition of matter; a computer program product embodied on a computer readable storage medium; and/or a processor, such as a processor configured to execute instructions stored on and/or provided by a memory coupled to the processor. In this specification, these implementations, or any other form that the invention may take, may be referred to as techniques. In general, the order of the steps of disclosed processes may be altered within the scope of the invention. Unless stated otherwise, a component such as a processor or a memory described as being configured to perform a task may be implemented as a general component that is temporarily configured to perform the task at a given time or a specific component that is manufactured to perform the task. As used herein, the term ‘processor’ refers to one or more devices, circuits, and/or processing cores configured to process data, such as computer program instructions.
A detailed description of one or more embodiments of the invention is provided below along with accompanying figures that illustrate the principles of the invention. The invention is described in connection with such embodiments, but the invention is not limited to any embodiment. The scope of the invention is limited only by the claims and the invention encompasses numerous alternatives, modifications and equivalents. Numerous specific details are set forth in the following description in order to provide a thorough understanding of the invention. These details are provided for the purpose of example and the invention may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the invention has not been described in detail so that the invention is not unnecessarily obscured.
A multicopter aircraft is disclosed. In various embodiments, the multicopter aircraft comprises multiple rotors, each mounted substantially horizontally on or near a distal end of a boom, i.e., an end of the boom that extends away from a central point, axis, fuselage, and/or other structure of the aircraft. The multicopter aircraft comprises a plurality of boom extensions, each boom extension being associated with a corresponding boom and each boom extension being configured to extend an associated end of said corresponding boom by an amount determined based at least in part on a swept area associated with a rotor mounted at or near said associated end. The aircraft additionally comprises a net or other non-rigid protective material (e.g., sailcloth, tarp) secured to said aircraft and having an outer free (unsecured) portion of a size sufficient to reach a far end of one or more of said boom extensions.
In various embodiments, the net or other material extended over said boom extensions provides a barrier between an occupant/user of the multicopter aircraft and said rotors, decreasing the likelihood that the occupant/user will come in contact with said rotors.
In some embodiments, the multicopter aircraft comprises four booms with a rotor attached at the two ends of each boom. Two booms may be arranged on top of and perpendicular to another two booms. A body of the aircraft may be positioned in the center of all four booms. Flotation devices may be attached underneath the booms. Boom extensions may extend the booms past the rotors. A net or multiple nets may be secured to ends of the boom extensions, covering the rotors. The aircraft may be designed to have a small form factor such that it can be easily transported when it is not flown. The aircraft may be designed for flight over water. The aircraft may be designed to crash safely without harming a pilot of the aircraft.
In some embodiments, fuselage 112 comprises a seat and a steering mechanism. The seat and steering mechanism may be designed for a human pilot. The fuselage may be uncovered. The absence of a covered or enclosed fuselage may be due to weight constraints. An open fuselage may allow a pilot greater visibility while flying over water. For example, mist and splashes from a water may hinder visibility to a greater degree in an enclosed fuselage. The fuselage may comprise a flight computer. The flight computer may implement autopilot safety features. For example, the flight computer may prevent the aircraft from tilting past a threshold angle, such as twenty degrees, in order to limit crashes. The flight computer may use sensors to prevent the aircraft from colliding with obstacles. The flight computer may be an off the shelf model such as a Pixhawk product.
In some embodiments, the multicopter aircraft has a length of 100 inches or less. The multicopter aircraft may qualify as an ultralight aircraft under federal aviation regulation guidelines. The multicopter aircraft may fit in a standard trailer designed to be towed by an automobile. In some embodiments, the aircraft is designed to be flown over water and as such does not have attached wheels. A small form factor may allow the aircraft to be easily towed over land. The multicopter may be designed to fit sideways in the trailer such that the width of the aircraft is relatively unconstrained in comparison to its length. For example, the four rotors on either side of the aircraft (e.g. rotors 106, 110, 126, and 124) may be larger than the other four rotors of the aircraft. The aircraft may be wider than it is long in order to have an increased wingspan and increased flight efficiency.
In the example shown, booms 306 and 310 are in parallel. Booms 300 and 304 are perpendicular to and attached to booms 306 and 310. Boom 304 originally extended at rotors 302 and 314 or at a short predetermined distance past the rotors (e.g. a few centimeters to a few inches). Boom extensions applied to boom 304 allow the boom to extend past the swept area of rotors 302 and 314. The swept area of a rotor may comprise the circular area that the rotor travels through when running. The boom may originally be a hollow tube and be open at both ends. The boom extensions may be hollow, open at one end, and closed at the other. The boom extension may be a tube of a greater or lesser diameter than the boom such that the open end of the boom extension and an end of the boom may be attached by sliding one tube into the other. A boom extension may plug into a boom up to a stopper or stopping point. A net or protective material may provide tension that holds the boom extensions in. The boom extensions may be always attached to the booms and be folded up when not in use. The boom extensions may be attached to the boom via screws, adhesives, interlocking parts, or any other appropriate method. The extensions may be installed before flight of the aircraft for safety reasons.
Flotation devices 506 and 524 may be attached underneath booms 520 and 522 respectively. In the example shown, rotors are represented by their swept areas. Rotors 500, 502, 504, 506, 508, 510, 512, and 5230 surround the fuselage. Using eight rotors to fly the aircraft may provide an element of redundancy. The power capability of each rotor may provide an element of redundancy wherein the rotors possess more power than is more than is required to fly the aircraft. The rotors may have a 1.3 to 1.6 thrust to weight ratio. The thrust to weight ratio may be designed to provide an element of redundancy. In some embodiments, in the event a rotor of the multiple rotors ceases to function the remaining rotors of the multiple rotors are sufficient to fly the aircraft in a level position. A rotor opposite a malfunctioning rotor may not be used in order to maintain balance in the aircraft. Motors used to rotate the rotors may have a maximum power of 10,000 to 15,000 watts, a diameter of 100 to 200 millimeters, or a weight of 2000 to 3000 grams. A rotor blade may have a length of 12 inches to 24 inches.
In some embodiments, the multiple rotors are angled to enhance torque in directional flight. The rotors may be angled to attain greater yaw authority or increased torque. For example, in the event the rotors are level, the aircraft pitches forward to create force as it flies forward. In the event the rotors are tilted forward, the aircraft does not need to pitch forward as far to achieve the same speed. Tilting the rotors may decrease a drag experienced by the aircraft. In some embodiments, some of the rotors are pitched forward whereas other rotors are pitched back. The rotors may be tilted at differing angles in order to efficiently move the aircraft in all directions. In the example shown rotors 500, 502, 512, and 506 may be tilted down such that the left side of the swept areas of the rotors as shown are at a lower altitude than the right side. Rotors 530, 504, 508, and 510 may be tilted or angled up.
In some embodiments, pairs of rotors of the multiple rotors rotate in opposite directions from each other to minimize torque. Each rotor produces a thrust and a torque about its center of rotation. With an equal number of rotors rotating in each direction, the aircraft's acceleration about the yaw axis may be canceled out. Rotating pairs of motors in opposite direction may allow an aircraft to hover without spinning. In the example shown, rotors 504, 508, 512, and 500 may rotate to the left whereas rotors 502, 506, 510, and 530 rotate to the right.
In some embodiments, the flotation devices are filled with air. The juncture of structures 608 and 610 with flotation device 600 may be reinforced to ensure no air escapes from flotation device 600. The flotation devices may be made of a material that is lightweight, waterproof, and resistant to tears and punctures. The flotation devices may be sewn or constructed such that it maintains a desired shape despite being filled with air. The flotation devices may be concave. In the example shown, flotation device 600 has ends that curve up and away from the water. In some embodiments, the flotation devices are curved to minimize interference with the multiple rotors' wash. For example, a rotor may be attached under the left end of boom 602. The curvature of flotation device 608 near structure 608 may decrease the extent to which flotation device 600 blocks air pushed by the rotor.
Although the foregoing embodiments have been described in some detail for purposes of clarity of understanding, the invention is not limited to the details provided. There are many alternative ways of implementing the invention. The disclosed embodiments are illustrative and not restrictive.
This application is a continuation of U.S. patent application Ser. No. 15/249,074 entitled MULTICOPTER WITH BOOM-MOUNTED ROTORS filed Aug. 26, 2016, now U.S. Pat. No. 10,183,747, which is incorporated herein by reference for all purposes.
Number | Name | Date | Kind |
---|---|---|---|
2953321 | Robertson | Sep 1960 | A |
3184183 | Plasecki | May 1965 | A |
4451016 | Genovese | May 1984 | A |
4655415 | Miller | Apr 1987 | A |
9902491 | Chan | Feb 2018 | B2 |
9946267 | Youmans | Apr 2018 | B2 |
20020125368 | Phelps, III | Sep 2002 | A1 |
20050230524 | Ishiba | Oct 2005 | A1 |
20060226281 | Walton | Oct 2006 | A1 |
20090008499 | Shaw | Jan 2009 | A1 |
20120032032 | De Roche | Feb 2012 | A1 |
20150379876 | Navot | Dec 2015 | A1 |
20160101850 | Lin | Apr 2016 | A1 |
20160244162 | Weller | Aug 2016 | A1 |
20160311526 | Geise | Oct 2016 | A1 |
20160340035 | Duru | Nov 2016 | A1 |
20160375982 | Rifenburgh | Dec 2016 | A1 |
20170029106 | Chang | Feb 2017 | A1 |
20170043870 | Wu | Feb 2017 | A1 |
20170185084 | Wang | Jun 2017 | A1 |
20180002001 | Daniel, Sr. | Jan 2018 | A1 |
20180319496 | Zhang | Nov 2018 | A1 |
Number | Date | Country | |
---|---|---|---|
20190106211 A1 | Apr 2019 | US |
Number | Date | Country | |
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Parent | 15249074 | Aug 2016 | US |
Child | 16209817 | US |