Multi-rotor Vehicle with Yaw Control and Autorotation

Abstract

An improved vehicle with superior performance and reliability. The vehicle, such as an unmanned aerial vehicle, is capable of vertical takeoff and landing, uses three swashless, variable-pitch vertical lift main rotors with a yaw tail rotor system. Two rear main rotors are optionally tiltrotors, which pivot to increase forward speed without the increased coefficient of drag inherent in tilting the entire vehicle. The three main rotors are positioned in an equilateral triangular configuration, improving balance, increasing load-bearing strength, and making it more compact in size. Movements are controlled through changes in pitch of the rotors, allowing the motors to maintain constant governed rotations per minute, maximizing drivetrain efficiency. Vehicle configurations disclosed herein allow for smaller vehicle size with greater performance than prior art vehicles.

Claims

1. A vehicle comprising a main rotor system; a yaw rotor system; and a fuselage; where the main rotor system comprises three independent rotor systems, where each independent rotor system comprises a swashless variable pitch rotor and a variable speed motor; where each rotor system is connected to the fuselage and is equidistant from the other rotor systems of the main rotor system; where the yaw rotor system comprises a yaw arm, a swashless variable pitch rotor, and a variable speed motor, where the yaw rotor system is located between two of the three rotor systems of the main rotor system.

2. The vehicle of claim 1, wherein two of the three rotor systems of the main rotor system are tiltrotor systems.

3. The vehicle of claim 1, wherein each rotor system of the main rotor system comprises a servo for controlling the pitch of the variable pitch rotor.

4. The vehicle of claim 1, wherein each rotor system of the main rotor system comprises multiple servos for controlling the pitch of the variable pitch rotor.

5. The vehicle of claim 1, wherein each rotor system of the main rotor system further comprises an autorotation hub.

6. The vehicle of claim 1, wherein each rotor system of the main rotor system comprises a gear, where the variable speed motor drives the gear, where the gear in turn drives the variable pitch rotor.

7. The vehicle of claim 1, wherein each rotor system of the main rotor system further comprises an autorotation hub and a gear, where the variable speed motor drives the gear, where the gear in turn drives the autorotation hub, which in turn drives the variable pitch rotor.

8. The vehicle of claim 1, wherein each of the rotor systems of the main rotor system is one-hundred twenty degrees away from the other two rotor systems of the main rotor system.

9. The vehicle of claim 1, wherein the yaw rotor system provides rotational control over the vehicle.

10. The vehicle of claim 1, wherein the variable pitch rotor of each rotor system of the main rotor system comprises a pitch slider.

11. The vehicle of claim 1, wherein each rotor system of the main rotor system comprises multiple servos, wherein the variable pitch rotor of each rotor system of the main rotor system comprises a pitch slider, where each servo drives the pitch slider of its respective rotor system of the main rotor system.

12. An unmanned aerial system comprising a main rotor system; a yaw rotor system; and a fuselage; where the main rotor system comprises three independent rotor systems, where each independent rotor system comprises a swashless variable pitch rotor, multiple servos, a variable speed motor, and an autorotation hub, where the multiple servos control the pitch of the variable pitch rotor, where each rotor system is connected to the fuselage and is equidistant from the other rotor systems of the main rotor system; where the yaw rotor system comprises a yaw arm, a swashless variable pitch rotor, and a variable speed motor, where the yaw rotor system is located between two of the three rotor systems of the main rotor system.

13. The unmanned aerial system of claim 12, wherein two of the three rotor systems of the main rotor system are tiltrotor systems.

14. The unmanned aerial system of claim 12, wherein each rotor system of the main rotor system further comprises a gear, where the variable speed motor drives the gear, where the gear in turn drives the autorotation hub, which in turn drives the variable pitch rotor.

15. The unmanned aerial system of claim 12, wherein each of the rotor systems of the main rotor system is one-hundred twenty degrees away from the other two rotor systems of the main rotor system.

16. The unmanned aerial system of claim 12, wherein the yaw rotor system provides rotational control over the unmanned aerial system.

17. The unmanned aerial system of claim 12, wherein the variable pitch rotor of each rotor system of the main rotor system comprises a pitch slider, where the multiple servos drive the pitch slider to control the pitch of the variable pitch rotor.

18. An unmanned aerial system comprising a main rotor system; a yaw rotor system; and a fuselage; where the main rotor system consists of three independent rotor systems, where each independent rotor system comprises a swashless variable pitch rotor, multiple servos, a variable speed motor, and an autorotation hub, where the variable speed motor drives the autorotation hub, which in turn drives the variable pitch rotor, where the multiple servos control the pitch of the variable pitch rotor, where each rotor system is connected to the fuselage and is equidistant and one-hundred twenty degrees away from the other rotor systems of the main rotor system; where the yaw rotor system comprises a yaw arm, a swashless variable pitch rotor, and a variable speed motor, where the yaw rotor system is located between two of the three rotor systems of the main rotor system, and where the yaw rotor system provides rotational control over the unmanned aerial system.

19. The unmanned aerial system of claim 18, wherein two of the three rotor systems of the main rotor system are tiltrotor systems.

20. The unmanned aerial system of claim 18, wherein the variable pitch rotor of each rotor system of the main rotor system comprises a pitch slider, where the multiple servos drive the pitch slider to control the pitch of the variable pitch rotor.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0045] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of this invention.

[0046] FIG. 1 is a perspective view of a vehicle according to selected embodiments of the current disclosure.

[0047] FIG. 2 is a diagram of rotor placement and direction of rotation for a vehicle according to selected embodiments of the current disclosure.

[0048] FIG. 3 is a cutaway perspective view of a portion of a rotor system of a vehicle according to selected embodiments of the current disclosure.

[0049] FIG. 4 is a cutaway side view of a portion of a rotor system of a vehicle according to selected embodiments of the current disclosure.

[0050] FIG. 5 is a perspective view of a portion of a rotor system of a vehicle according to selected embodiments of the current disclosure.

[0051] FIG. 6 is a perspective view of a yaw system according to selected embodiments of the current disclosure.

[0052] FIG. 7 is a top view of a yaw system with redundant rotors according to selected embodiments of the current disclosure.

[0053] FIG. 8 is a perspective view of an unmanned aerial vehicle according to selected embodiments of the current disclosure.

DETAILED DESCRIPTION OF THE FIGURES

[0054] Many aspects of the invention can be better understood with references made to the drawings below. The components in the drawings are not necessarily drawn to scale. Instead, emphasis is placed upon clearly illustrating the components of the present invention. Moreover, like-reference numerals designate corresponding parts through the several views in the drawings. Before explaining at least one embodiment of the invention, it is to be understood that the embodiments of the invention are not limited in their application to the details of construction and to the arrangement of the components set forth in the following description or illustrated in the drawings. The embodiments of the invention are capable of being practiced and carried out in various ways. In addition, the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.

REFERENCE NUMBERS USED

[0055] 1Swashless Pitch Slider [0056] 2Autorotation Hub [0057] 3Gear [0058] 4Independent and Active Rotor Drive in Yaw [0059] 5Redundant System Servos in Yaw [0060] 6Independent and Active Rotor Drive in Main [0061] 7Redundant System Servos in Main [0062] 8Rear Main Rotor Systems [0063] 9Equilateral triangle [0064] 10Dual Rotor [0065] 11Tiltrotor [0066] 12Fuselage [0067] 13Main Body [0068] 14Pitch Slider (Yaw) [0069] 16Yaw Arm [0070] 18Electronics Housing [0071] 21Main Rotor System [0072] 22Yaw Rotor System [0073] 25Propeller (Main) [0074] 26Propeller (Yaw) [0075] 30Front Rotor System

[0076] The aerial vehicle, according to selected embodiments of the current disclosure, has some traditional, and some very untraditional components. There is a base, that houses the battery, software, and other parts of the brains of the vehicle. There are three propeller arms, that serve to locate three propeller blades a set distance away from the base and each other. In direct contrast to the prior art, embodiments of the vehicle disclosed herein also has a yaw control arm that is attached to a vertically oriented yaw blade, which is a propeller that controls the yaw of the vehicle.

[0077] FIG. 1 is a perspective view of a vehicle according to selected embodiments of the current disclosure. As can be seen in this figure, when the propellers 25 of the main rotor systems 21 are moving the vehicle forward or backward, the yaw propeller 26 of the yaw rotor system 22 can control the rotation or yaw of the vehicle. Thus, the current disclosure provides for the combination of the best of current unmanned aerial vehicles on the market today with helicopter technology.

[0078] Looking at the components of the vehicle, the yaw system or control unit 22 has a yaw arm 16 that extends the unit away from the main body. Certain embodiments provide for the yaw arm 16 extending away from the center of gravity of the vehicle. However, as opposed to the prior art of quadcopters in which each main rotor system is located 90 degrees from the two adjacent ones, embodiments of this disclosure provide that the lifting units, or three main rotor systems, are located one-hundred twenty degrees (120) away from each other, thereby providing the inherently stable triangle design.

[0079] Each main rotor systems 21 includes a pitch slider 1, autorotation hub 2, and gear 3, shown in more detail in subsequent drawings. The yaw rotor system 22 has a motor 4 and system servos 5. Likewise, the main rotor systems 21 have motors 6 and system servos 7. There are rear main rotor systems 8 and a front rotor system 30. The main body 13 includes electronics housing 18.

[0080] FIG. 2 is a diagram of rotor placement and direction of rotation for a vehicle according to selected embodiments of the current disclosure. The main rotor systems 21 are equidistant from the other main rotor systems 21, whereby each is 120 from the other. The center point of each propeller of the main rotator system forms an equilateral triangle 9. The two rear main rotor systems 8 rotate in opposite directions, as indicated in this figure, thereby cancelling the torque or yaw applied to the vehicle from each of these two rear main rotor systems 8. As will be appreciated by those skilled in the art, the propellers of the rear main rotor systems 8 may rotate in a direction opposite of that indicated in this figure while achieving the same functional purpose. The yaw rotor system 22 is located between the two rear main rotor systems 8, and in this embodiment, is equidistant between the two rear main rotor systems 8.

[0081] As discussed in more detail below, the three main rotor systems may consist of two pivoting or rotating rotors systems and a fixed front rotor system, each of which are 120 away from the other. The yaw rotor system 22 is located in between the two main rear rotor systems 8 so as not to disrupt the spacing of the lifting propeller units. The purpose of the yaw rotor system, or yaw control unit, is to give the user some rotational control over the vehicle without having to use the lifting propellers to do this work. This saves significantly on battery power since the current prior art changes the speed of the lifting propellers to control yaw. There is also an electronics housing 18 integrated with the main body 13 that houses batteries, Antenna/GPS, and other electronics therein for 3D communications. The front rotor system 30, or front propeller unit, helps to control the vertical location of the vehicle and, as one corner of an equilateral triangle, provides inherent stability to the vehicle.

[0082] Because each of the three lifting propellers is located 120 degrees from the two adjacent ones, the invention avoids the retreating blade stall problems that limit the forward speed at which helicopters fly.

[0083] FIG. 3 is a cutaway perspective view of a portion of a rotor system of a vehicle according to selected embodiments of the current disclosure. This portion of the rotor system includes a pitch slider 1 that controls the pitch of the propeller blades rotating about its axle. A gear 3 drives the axle via an autorotation hub 2. As discussed below, the autorotation hub 2 allows for the propellers to continue spinning or rotating even though the gear 3 may have stopped rotating, for example, due to a motor that has stopped.

[0084] FIG. 4 is a cutaway side view of a portion of a rotor system of a vehicle according to selected embodiments of the current disclosure. The rotor system includes a gear 3 that drives an autorotation hub 2, which then in turn drives the propellers 25. System servos 7 drive a pitch slider 1, which in turn causes the blades of the propeller 25 to change pitch. Multiple system servos 7 are used to create a level of redundancy, whereby if a single system servo 7 fails, the other system servo 7 may nonetheless continue driving the pitch slider 1.

[0085] FIG. 5 is a perspective view of a portion of a rotor system of a vehicle according to selected embodiments of the current disclosure. A motor, or rotor drive 6, provides power to rotate the propellers via the gear and autorotation hub discussed above.

[0086] FIG. 6 is a perspective view of a yaw system according to selected embodiments of the current disclosure. The yaw system includes a motor, or rotor drive 4 that provides rotational power to the propeller 26. The rotor drive 4 of the yaw system is mounted horizontally, compared to the vertical orientation of the rotor drive 6 of the main rotor systems. System servos 5 drive a pitch slider 14, which in turn causes the blades of propeller 26 to change pitch. Multiple system servos 5 are used to create a level of redundancy, whereby if a single system servo 5 fails, the other system server 5 may nonetheless continue driving the pitch slider 14.

[0087] FIG. 7 is a top view of a yaw system with redundant rotors according to selected embodiments of the current disclosure. As with the embodiment shown in FIG. 6, the rotor drive 4 is mounted horizontally, but in this embodiment, drives two propellers 10. While particular embodiments provide for the two propellers 10 rotating in the same direction, counter rotating propellers, that is propellers rotating in opposite directions, reduce the net torque applied by the rotating propellers on the yaw system and consequently the main body. System servos 5 drive a pitch slider, which in turn causes the blades of the propellers to change pitch. Multiple system servos 5 are used to create a level of redundancy, whereby if a single system servo 5 fails, the other system server 5 may nonetheless continue driving the pitch slider.

[0088] Particular embodiments of the current disclosure provide for the aerial vehicle having two pivoting rear main rotor systems, which are very similar in shape and design to the front rotor system 30, but they additionally have a pivot section built into the rotor system arm that allows the unit to be set at different angles to allow for different movement of the vehicle. It is important to note that in between the yaw rotor system 22 and the main rotor systems 21, there is no need to change the speed of any one propeller to affect the yaw or angle of the vehicle; these units can operate at or near full speed all the time, thereby allowing for a more efficient operation and longer battery life. The variable pitch aspect of this invention avoids the need to accelerate and decelerate individual engines, and it also avoids the swashplate complexity, cost, and maintenance that are required to build and maintain a helicoptereven a toy one. Running the propellers continuously at or near maximum power is a more efficient way to power a vehicle and results in great movement capabilities for the same amount of battery power as compared with a drone that wastes power winding up and window down its engines constantly. Because of the more efficient power feature, vehicles according to the current disclosure can use smaller propellers that do the prior art drones, which provides important space-saving features, particularly for drone flyers who travel with their drones.

[0089] FIG. 8 is a perspective view of an unmanned aerial vehicle according to selected embodiments of the current disclosure. Two of the three main rotor systems are tiltrotor systems 11, whereby the angle of the rotor system may be changed to angle the propellers of that rotor system. The tilt rotor systems 11 rotate relative to the fuselage 12. As can be seen in this figure, the title rotors rotate about an axis that is off center from the longitudinal axis of that rotor system. Rotation about the longitudinal axis of the rotor system would cause the propellers to angle towards or away from the yaw system, and provide counter-acting forces which reduce efficiencies. Instead, by rotating about an off center axis, the tilt rotors can be angled such that each is providing substantially all or all forward and vertical thrust (that is a thrust causing the vehicle to move forward), with little to now horizontal or side to side thrust.

[0090] It should be noted that the main rotor systems have the capacity to disengage from the engine gearing of the main drive system in the event of a power loss through the use of auto-rotation hubs. The disengagement allows for auto-rotation of the blade, which will slow the descent of the unit. Current drones have propellers that are locked to the gearing that connects them to the motors, so if power fails, the propellers are frozen into position (at least until the drone hits the ground at full gravitational speed, which usually results in the propellers, camera and other sensitive parts of the drone being broken off if not completely destroyed). The auto-rotation hub acts similar to that of a bicycle wheel and gear system, whereby power is applied to the wheel (propeller) when pedaling (motor provides power), but the wheel (propeller) is allowed to freely rotate when not pedaling (loss of power from motor).

[0091] Because the lifting propellers are used only for flying, the vehicle can use propellers that are smaller than those currently on similar sized unmanned aerial systems. This saves money, but also saves space, which is very important. For a serious UAS operator, having a vehicle that can be packed compactly for travel is very important, as most flyers want to take their drones as carryon items. In addition, by having fewer moving (and non-moving parts), as compared with current drones, the vehicles disclosed herein are relatively less expensive to build, and less expensive to maintain.

[0092] In terms of providing electrical power, rechargeable batteries are contemplated as one source of power. It is envisioned that alternative sources of power may be utilized, including power plants like anti-gravity engines or any elements, i.e.; element 116 from the Periodic Table of Elements, whose atomic characteristics are feasible for the production of clean and sustainable alternative sources of energy.

[0093] To make the vehicles disclosed herein, the components can be made with known machine tools from known materials in known ways. For instance, components of this device can be made with computer aided drafting (CAD) or computer aided machining (CAM) possible on a computer numerical control (CNC) machine. These known materials can include existing materials as well as composites of existing materials. It is expected that plastic and plastic composites will be primarily used to make the body portions and the propellers.

[0094] The power sources could be any of a variety of known sources such as internal combustion engines, electric engines, turbine engines, fuel cells, ramjet, pulse jet, nuclear, solar, as well as power regenerative type systems. Any fly-by-wire flight controller can be used for flight manipulation. Alternative variable pitch system can be used to transfer rotational energy from the engine into variable thrust. The variable pitch thrust system can be controlled through the use of any of the following: servos, actuators, hydraulics, or magnetic coils such as hard drive actuators. By utilizing a variable pitch system, it has been determined that this vehicle can achieve 99.9% efficiency by allowing the power plant to run at its optimum efficiency. A one-way hub is used in order to make the variable pitch system auto-rotation capable. The disengagement of the vertical rotors from the drive system through the use of a one-way hub allows the rotors to gain or maintain speed as it slowly descends back to the ground. Although this vehicle is balanced on its center of gravity, it is not critical and the vehicle can compensate for added weight off of its center of gravity. Its center of gravity can be defined by finding the center of the equilateral triangle between the three 120 degree vertical rotors. The anti-torque yaw system also utilizes a variable pitch propeller system for maximum control. Both vertical lift and anti-torque yaw variable pitch systems can be powered either through a gear/gear, belt/gear, shaft/gear, motor/gear type systems or directly. A turbine engine may be used in place of the variable pitch system.

[0095] In another embodiment, the vehicle has a solid shell that encapsulates the main body, thereby providing the additional benefit of waterproof capabilities. In this embodiment, there are three distinct types of propeller units: A front unit that remains horizontally oriented, two pivoting propeller units that can pivotally rotate to give enhanced control (both in the air and under water) to the user of the vehicle, and a yaw control unit, which incorporates helicopter technology to control the yaw of the unit.

[0096] By pivoting the two tiltrotor systems forward, the propeller units provide forward thrust. The yaw control unit trails behind as a sort of rudder which can be used to control the yaw and direction of the drone. Notice how all or nearly all of the battery power used by the pivoting propeller units can be used to fly the drone, as the yaw control unit controls rotation and provides directional control.

[0097] The waterproof body of the drone could contain ballast tanks that are selectively flooded and emptied to direct the vehicle under water or back up to the surface. In the submersible version, there would be additional corrosion inhibitors built into the joints between the various parts. As with the solely-aerial version, the tilting propeller units would the provide the thrust and the yaw control unit would steer the drone.

[0098] Selected embodiments of the current disclosure provide for a vehicle that is usable in both air and water because of its advanced design. Ballast tanks are provided that can be opened and purged to give the vehicle a negative or positive buoyancy. To propel the vehicle in its submersible phase, the same propellers that provide lift on land will be used. Because the propellers can pivot forward, they can act just like a propeller on a regular ship or submarine. The vehicle in this embodiment will have a waterproof body with adequate pressure compensating fittings and other additional waterproofing parts, along with either a physical cable connection or some other means of communication with the vehicle while it is underwater. For example, the user could rely upon predetermined way point programming, where the user sets a map of the direction he/she wants the vehicle to travel before the vehicle enters the water. Alternatively, the vehicle could rely on the use of sonar-like systems to build itself a virtual environment and send information back above sea level to show vehicle's progress and location. The vehicle could also use surface ships as repeaters, and or satellite navigation. This list of examples of control is not meant to be restrictive in any way, and any known means of communicating with a machine under water, or in pre-programming movement of a machine under water is contemplated as potentially working with the vehicle disclosed herein.

[0099] Embodiments of the current disclosure incorporate the aspects of fixed wing aircraft, helicopters and current drones to create a vehicle with superior handling, battery life, and safer operation, in both air and aquatic environments, including operation on the surface of an aquatic environment.

[0100] It is also relevant that these technologies could be used on large scale vehicles, capable of carrying cargo or humans. The energy-saving and superior control technologies are relevant to mini-drones the size of a person's hand, and full size aerial vehicles the size of a 747 or A-380 airplane, or even as large as the super blimps being proposed that are thousands of feet long. The technology is applicable to any flying object, regardless of size, and with any surface/submersible object, regardless of size.

[0101] It should be understood that while the preferred embodiments of the invention are described in some detail herein, the present disclosure is made by way of example only and that variations and changes thereto are possible without departing from the subject matter coming within the scope of the following claims, and a reasonable equivalency thereof, which claims I regard as my invention.