FIELD OF THE INVENTION
[001] The present invention relates to an Electrical Vertical Take-off and Landing (E-VTOL) aircraft using tilt rotor and folding wings, and more particularly the present invention relates to systems, devices, and methods for transporting one or more passenger with the infusion of electric propulsion and autonomous flight control in an electrical tilt-rotor aircraft with folding wing.
BACKGROUND OF THE INVENTION
[002] There are many electrical vertical Take-off and landing (E-VTOL) aircrafts as well as passenger drones worldwide as an alternative to conventional aircrafts and helicopters. In recent years, a number of field trials and research studies have been undertaken by various organization for developing a new kind of E-VTOL aircraft technology. Tilt-rotor aircrafts are already present in the prior-arts says for example Bell V-22 Osprey with less lift to drag ratio, low propulsive efficiency and high structure weight.
[003] Conventional Tilt-rotor aircraft use gear box mounted on drive shaft to tilt propulsion unit which require regular lubrication and maintenance. Quad Tilt-rotors with fixed wing are much better in aerodynamic stability, Performance and endurance. There have been a number of researches provided for findings indicate the use of foldable propeller blades, and a propeller-hub assembly which may be utilized in a VTOL aircraft having various characteristics and few of them have been discussed below:
[004] US 8544787 B2 discloses a tilt rotor aircraft in which a nacelle tilt angle and a flaperon angle mechanically interlock with each other. In the tilt rotor aircraft having nacelles in which rotors are mounted in left and right main wings. The nacelles rotate according to whether the tilt rotor aircraft conducts forward flight or vertical take-off and landing flight. Further, each of the main wings is provided with a flaperon. The nacelle and the flaperon are connected to each other by a power transfer unit, enabling the flaperon also rotates together with the nacelle at the time of rotation of the nacelle, thereby allowing a change in a nacelle tilt angle to lead to a change in a flaperon angle.
[005] US 2011/0180657 A1 relates to an aircraft wing folding system which folds an outboard wing section relative to an inboard wing section between a deployed position and a stored position in two discrete motions where each motion has an independent load path separate of the loading of the wing experienced by in-flight aerodynamic forces. The wing-fold mechanism includes a fold assembly comprising a twist component and a fold component operable to fold the outboard wing section from the deployed position to the stored position that remains substantially unloaded with respect to in-flight aerodynamic forces when the wing is in the deployed or flight configuration.
[006] The aforesaid VTOL aircrafts come under flying taxi or cargo delivery services and does not fit for personal flying vehicle. However, they still have a number of limitations and shortcomings such as, but not limited to, maintenance cost, autonomous flight control system, and require a very large parking area. The above mentioned prior arts can only perform certain aspects say for example provides a vertical take-off and landing function, rotating rotors and a two-motion wing-fold mechanism with an independent flight load path etc.
[007] Accordingly, there remains a need in the prior art to have a safest, Cost effective, Compact, Environmental friendly and fully autonomous personal E- VTOL aircraft system. The present invention is having advancement in Tilt-rotor technologies, which result in good aerodynamic stability, high propulsive efficiency and avoiding mechanical cross shaft for tilting mechanism, therefore overcome the aforesaid problem and shortcomings.
OBJECTS OF THE INVENTION
[008] Some of the objects of the present invention satisfied by at least one embodiment of the present invention are as follows:
[009] An object of the present invention is to provide an E-VTOL Tilt-rotor aircraft with folding wing that can be used for daily commute within, but not limited to, the urban cities and all over the world where road traffic congestion is at utmost.
[010] Yet another object of the present invention is to reduce the maintenance cost by using all electric motor to drive propeller.
[011] Another object of the present invention is to provide autonomous flight control system for eliminating pilot/passenger skill requirement and further improves safety of this E-VTOL aircraft with tilt rotor and foldable wings.
[012] Still another object of the present invention is to provide an aircraft with compact size that takes very less parking space due to its foldable wings as compared to other E-VTOL fixed wing aircraft. These and other objects and advantages of the present invention will become more apparent from the following description, when read with the accompanying figures of drawing, which are however not intended to limit the scope of the present invention in any way.
SUMMARY OF THE INVENTION
[013] In the view of the foregoing disadvantages inherent in the known types of system, the Tilt-rotor aircrafts with all the advance technology are not able to compete with fixed wing aircrafts in payload-class, now present in the prior art, the present invention provides an autonomous E-VTOL aircraft system having tilt rotor with folding wings. As such, the general purpose of the present invention to provide the affordable aircraft system for people as compared to similar technology, which will be described subsequently in greater detail, is to provide a new and improved, which has all the advantages of the prior art and none of the disadvantages.
[014] In accordance with an aspect of the present invention, an autonomous E-VTOL aircraft has the following mode of flights: vertical takeoff, hovering, transition, cruise, hovering, and vertical landing.
[015] In accordance with another aspect of the present invention, the E-VTOL aircraft includes of four propeller units, each having two sets of co-axial, contra rotating motors and propellers. Further, the propellers and motors, the propeller unit advantageously comprises of a duct around the propeller so as to direct and increase the thrust generated by propellers and additionally reduce the noise levels and provide safety to the person nearby the rotating propellers.
[016] In accordance with another aspect of the present invention, the propeller units are electrically adjustable in orientation with respect to the fuselage to steer the aircraft.
[017] In accordance with another aspect of the present invention, for vertical takeoff, landing and hover phase of the E-VTOL aircraft the propeller units are parallel to the horizontal plane directing the thrust downward.
[018] In accordance with another aspect of the present invention, in hovering mode the propeller units of the E-VTOL aircraft is parallel to horizontal plane and in cruise flight mode the propeller units is perpendicular to horizontal plane. During the transition phase of the E-VTOL aircraft from hovering to cruise flight mode, the position of the propeller units of the E-VTOL aircraft are changed from parallel horizontal plane to perpendicular horizontal plane and vice-versa. The thrust from the each propeller unit is adjusted till the stable cruise flight mode is achieved. The thrust vectoring is produced by the after / rear propeller unit of the E-VTOL aircraft, and further, the differential thrust is provided by the other propeller units for stabilizing the flight movement of the aircraft.
[019] In accordance with another aspect of the present invention, the E-VTOL aircraft consists of foldable wings to make the aircraft compact and reduce the parking space. The wings of the aircraft are in folding position for parking, vertical takeoff and landing phase of the flight. The wings of the aircraft are unfolded in a secured manner by providing a locking unit to prevent the unnecessary movement of the wings before the transition phase during hovering.
[020] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
[021] These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[022] The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
[023] FIG. 1 illustrates the view of an E-VTOL aircraft on ground with folded wing in upward direction that is perpendicular to fuselage longitudinal axis, in accordance with an embodiment of the present invention;
[024] FIG. 2 illustrates the autonomous E-VTOL aircraft with unfolded wing and propeller parallel to fuselage horizontal plane; & FIG. 2A illustrates the autonomous E-VTOL aircraft with unfolded wing and propeller parallel to fuselage vertical plane, in accordance with another embodiment of the present invention;
[025] FIG. 3 depicts the E-VTOL aircraft in transition phase that is from hovering mode to cruise mode in accordance with another embodiment of the present invention;
[026] FIG. 4 & 4A depicts front and side view of the E-VTOL aircraft in cruise mode in accordance with another embodiment of the present invention; and
[027] FIG. 5 depicts the top view of the E-VTOL aircraft in cruise mode in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[028] In the following detailed description, reference is made to the accompanying drawings which form a part thereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that the embodiments may be combined, or that other embodiments may be utilized and that structural and logical changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents.
[029] Referring now to the drawings, there is illustrated, in FIG. 1 & 5, an improved autonomous aircraft in the form of an Electrical vertical take-off and landing (E-VTOL) aircraft (100) with tilt rotor (105A, 105B, 105C, 105D) and foldable wings (110A, 110B), comprising a fuselage, foldable wings (110A, 110B) and at least two electrical propeller unit. The E-VTOL acronym will be used for this aircraft in the given description. The fuselage is having a longitudinal axis, and foldable wings are extending each along an axis from the fuselage symmetrically with respect to the longitudinal axis of the fuselage. The electrical propeller unit is arranged on each side of the fuselage longitudinal axis, wherein each of the propeller units comprises two electrical motors and two propellers (contra-rotating) arranged co-axially, directly or indirectly linked to an arbor of the electrical motor so as to rotate about an axis of rotation.
[030] In accordance with an embodiment of the present invention, each of the propeller units being tiltable in a vertical plane containing the propeller's axis of rotation. Further, each of the propeller units being electrically connected to primary electrical energy, i.e. a battery source disposed in the fuselage. Preferably, the primary electrical energy source is rechargeable battery having energy density of, but not limited to, 150Wh/kg and power density 2kW/kg.
[031] In accordance with an embodiment of the present invention, the battery source comprises of four modules. Each module to support at least two brushless DC motors BLDC motors. Battery modules are placed such that it will help in balancing the overall center of gravity of the aircraft. In case of failure of any module we can run the BLDC motor through remaining module. There is a secondary rechargeable battery which comprises of two modules. One module is for operating all the avionics and actuation systems, other module is backup source for both avionics and actuation systems.
[032] In accordance with another embodiment of the present invention, the E-VTOL aircraft is driven by electrical propulsion using highly efficient BLDC motor and carbon fiber propeller. A plurality of ducts is used to generate excess thrust from co-axial contra rotating propeller unit. Occupant and nearby people’s safety is ensured by shroud integration in the E-VTOL aircraft design. Preferably, the aircraft rotors can tilt from 0 degree to 90 degree and vice versa by using simple electromechanical mechanism avoiding complex mechanical cross shaft mechanism as already been used in many tilt-rotor aircrafts says for example V – 22 and the like.
[033] In accordance with another embodiment of the present invention, the E-VOL aircraft further comprises a vertical tail with rudder arranged at the tail of the aircraft for stabilized yaw steering of the aircraft. The E-VTOL aircraft is configured to utilize thrust vectoring by the after or rear propeller units for stabilized pitch steering of the aircraft without placing elevator. The E-VTOL aircraft utilizes ailerons 115A, 115B for stabilized roll steering of the aircraft.
[034] The E-VTOL aircraft uses eight contra rotating propeller units for vertical takeoff and landing and in cruise as well. FIG. 2 shows the preferred embodiment in which E-VTOL aircraft can hover for a predetermined time by using continuous power from the battery source. FIG. 2, further shows the deployed wing before it goes into flight transition phase.
[035] FIG. 3 illustrates, the aircraft in transition phase switching from hover mode to cruise flight mode by tilting rotors at desired angle and unfolded wings. FIG. 4 & 4A present various views of aircraft in cruise flight mode with a predetermined velocity and lift is generated by wing making cruise flight energy efficient. The E-VTOL aircraft is configured to have roll flight movement control provided by aileron 115A, 115B, yaw flight movement control provided by rudder 120 and pitch flight movement control provided by thrust vectoring as shown in FIG. 2 & 2A. Aircraft perform vertical takeoff and landing with thrust produced by all propellers unit parallel to fuselage longitudinal datum plane.
[036] In accordance with another embodiment of the present invention, the motors are configured to power by the rechargeable batteries. Stable takeoff, transition, hover, cruise and landing are relied on energy from the rechargeable battery source. During takeoff and transition the maximum power is required. During cruise flight power requirement from the battery source is less. The battery is selected based on the targeted at least, but not limited to, 1 hour endurance and power requirement of the motor at different instances i.e. takeoff, transition, hover, cruise and landing.
[037] In accordance with another embodiment of the present invention, the battery technology is evolving and further, the relevant battery technology is not describing for the sake of brevity of the present invention and selected from the currently available battery solution is used for the E-VTOL aircraft. A lot of research is going on to improve the existing battery technology in terms of energy density, power density etc. Many prior-arts are having various kind of battery chemistry says for example Lithium-ion, Lithium-Polymer and the like with expected energy density of 180- 250Wh/kg. As the existing battery technology improves further then the targeted endurance of at least, but not limited to, 1 hour and 100kms range shall also increase with the relevant future battery technology.
[038] The present invention offers maximum range and endurance among its electrical VTOL tilt-rotor and fixed wing aircraft category. Folding wing design makes this E-VTOL aircraft very compact in size during vertical takeoff and landing. This E-VTOL aircraft is most compact if one consider similar fixed wing with tilt rotor aircrafts. This E-VTOL aircraft is very light in weight by using carbon composite structure which makes it very energy efficient one or more passenger flying vehicle. The present invention is invented to solve the city’s traffic congestion problem. This E-VTOL aircraft can fly over congested cities and populated areas fully autonomously without interference of boarded human being.
[039] The above-mentioned autonomous E-VTOL aircraft, exploits advanced electric propulsion technology together with highly efficient, autonomously piloted Vertical Take-Off and Landing (VTOL) systems. The E-VTOL aircraft has the aim of bringing the VTOL capable aircraft to a completely new status and commercial relevance and viability with a tilt-propeller design relying on electrical power as energy for driving tillable propeller units. The E-VTOL aircraft offers a safe, legal, and practical flying vehicle to operate within populated, built-up localities, and to achieve speeds and ranges competitive with current fixed wing, propeller-driven aircraft, while less efficient rotary wing aircraft (e.g., helicopters and quad copters etc.) innately show lower lift-to-drag ratios preventing them from competing with fixed-wing, propeller-driven aircraft in speed and range.
[040] It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-discussed embodiments may be used in combination with each other. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description.
[041] The benefits and advantages which may be provided by the present invention have been described above with regard to specific embodiments. These benefits and advantages, and any elements or limitations that may cause them to occur or to become more pronounced are not to be construed as critical, required, or essential features of any or all of the embodiments.
[042] While the present invention has been described with reference to particular embodiments, it should be understood that the embodiments are illustrative and that the scope of the invention is not limited to these embodiments. Many variations, modifications, additions and improvements to the embodiments described above are possible. It is contemplated that these variations, modifications, additions and improvements fall within the scope of the invention.

CLAIMS:We Claim:
1. an Autonomous Electrical vertical take-off and landing (E-VTOL) aircraft 100, comprising:
foldable wings (110A, 110B, 110C, 110D) with a locking unit;
a tiltable rotor (105A, 105B, 105C, 105D)adapted to move in a defined axis for providing vertical take-off and landing to the aircraft and working as a propeller unit;
wherein the E-VTOL aircraft is configured to utilize thrust vectoring by the after or rear propeller units for stabilized pitch steering of the aircraft without placing elevator;
wherein the aircraft in transition phase switching from hover mode to cruise flight mode by the tilting rotors at desired angle; and
wherein the aircraft is configured to have roll flight movement control provided by aileron 115, yaw flight control provided by rudder and pitch flight movement control provided by thrust vectoring.
2. The E-VTOL aircraft as claimed in claim 1, wherein the foldable wings (110A, 110B, 110C, 110D) are further comprised of a locking unit.
3. The E-VTOL aircraft as claimed in claim 2, wherein the locking unit is activated on the defined movement of the foldable wings (110A, 110B, 110C, 110D).
4. The E-VTOL aircraft as claimed in claim 1, wherein the aircraft further comprises a vertical tail with a rudder 120 arranged at the tail of the aircraft for stabilized yaw steering of the aircraft.
5. The E-VTOL aircraft as claimed in claim 1, wherein the differential thrust is produced by the propeller unit.
6. The E-VTOL aircraft as claimed in claim 1, wherein the aircraft is having thrust vectoring by the after / rear propeller units for stabilizing the flight movement of the aircraft.
7. The E-VTOL aircraft as claimed in claim 1, wherein the Aircraft performs vertical takeoff and landing with thrust produced by all propellers unit parallel to fuselage longitudinal datum plane.
8. The E-VTOL aircraft as claimed in claim 1, wherein the aircraft utilizes aileron 115A, 115B for stabilized roll steering of the aircraft.
9. The E-VTOL aircraft as claimed in claim 1, wherein the aircraft uses eight contra rotating propeller units for vertical takeoff and landing and in cruise.
10. The E-VTOL aircraft as claimed in claim 1, wherein each of the propeller units comprises two electrical motors and two propellers (contra-rotating) arranged co-axially, directly or indirectly linked to an arbor of the electrical motor so as to rotate about an axis of rotation.