All-electric multirotor full-scale aircraft for commuting, personal transportation, and security/surveillance

• US 9,242,728 B2
• Filed: 08/05/2014
• Issued: 01/26/2016
• Est. Priority Date: 08/07/2013
• Status: Active Grant

• Current Assignee: Alakai Technologies Corporation (Guardian Mobility Corp.)
• Original Assignee: Alakai Technologies Corporation (Guardian Mobility Corp.)
• Inventors: Morrison, Brian D.
• Primary Examiner(s): Shafi, Muhammad
• Application Number:
  US14/452,245
• Publication Number:
  US 20150353192A1
• Time in Patent Office: 539 Days
• Field of Search: 701/3, 701/4, 244/17.23, 244/17.25, 244/17.27, 244/26, 244 6- 11
• US Class Current: 1/1
• CPC Class Codes: B64C 27/08 with two or more rotors
• CPC Class Codes: B64C 27/32 Rotors
• CPC Class Codes: B64C 27/56 characterised by the control initiating means, e.g. manually actuated
• CPC Class Codes: B64C 27/57 automatic or condition responsive, e.g. responsive to rotor speed, torque or thrust
• CPC Class Codes: B64D 27/24 using steam or spring force jet aircraft B64D27/16
• CPC Class Codes: B64D 31/04 actuated personally
• CPC Class Codes: B64D 31/06 actuated automatically
• CPC Class Codes: B64D 43/00 Arrangements or adaptations of instruments arrangements of cameras B64D47/08; aeronautical measuring instruments per se G01C
• CPC Class Codes: G01C 23/005 Flight directors indicating arrangements specially adapted for rotary gyroscopes G01C19/32
• CPC Class Codes: Y02T 50/50 On board measures aiming to increase energy efficiency
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

Methods and systems for a full-scale vertical takeoff and landing manned or unmanned electric aircraft, having an all-electric, non-hydrocarbon-powered lift and propulsion system, an integrated avionics system for navigation and guidance, and simple joystick and throttle controls to provide the operator with ‘drive by wire’ style direction control. The vehicle employs counter-rotating sets of propellers and lift is provided by multiple pairs of small electric motors driving directly-connected, counter-rotating sets of propellers. Automatic computer monitoring by one or a plurality of programmed redundant digital motor management computer or autopilot controls each motor-controller and motor to produce pitch, bank and elevation, while simultaneously restricting the flight regime that the pilot can command. Sensed multi-axis information and parameter values about vehicle state are used to provide stable vehicle control and to detect when stable vehicle operating limits are about to be exceeded.

Claims

1. A full-scale, multirotor vertical takeoff and landing (vtol) electric aircraft system capable of transporting a plurality of human occupants and payload, comprising:

a. a multirotor vtol electric aircraft having a plurality of components;

b. a system comprising the plurality of components where the system comprises safety and reliability attributes necessary to safely and reliably transport human occupants and satisfy Federal Aviation Administration (FAA) or International Civil Aviation Organization (ICAO) regulatory safety-of-flight rules;

c. a physical airframe structure which mounts the plurality of components, capable of supporting a weight of the multirotor vtol electric aircraft with one or a plurality of human occupants and payload;

d. a physical motor attachment structure that provides mounting attachments for a plurality of electric motor and propeller subassemblies, and that transfers lift generated by the motor and propeller subassemblies to the airframe, passengers, and payload;

e. a plurality of electric motor and propeller subassemblies reliably attached to the multirotor attachment structure and connected to the airframe or fuselage;

f. the plurality of electric motor and propeller subassemblies comprising pairs of motor and propeller subassemblies where each pair comprises two counter-rotating motors and counter-rotating propellers;

g. the plurality of electric motors being controlled by a plurality of electric motor controllers;

h. a ground support structure comprising landing skids or wheels capable of supporting the airframe structure and a plurality of occupants, avionics, motors, electronics and batteries;

i. the plurality of motor electric controllers to control a commanded voltage and torque generated by each motor and to measure its performance, comprising RPM and voltage and current;

j. a motor control or autopilot system comprising the plurality of motor electric controllers or autopilots, where the redundancy satisfies the safety and reliability required to meet regulatory safety-of-flight rules;

k. an On/Off switch connected to a high-current fuse and high-current contactor that isolates a battery system from a remainder of the system when the battery system is not required or is being charged, the battery system comprising a plurality of rechargeable high-energy density batteries connected in serial and parallel configurations to supply a required voltage and current;

l. a battery charger comprising a unit configured to receive external power accessed through a charging connector to recharge the batteries after use;

m. a battery display system that outputs performance metrics for the batteries;

n. a safety switch configured to provide a means of disabling and enabling an entire motor system;

o. an external charging connector compatible with infrastructure chargers for the multirotor vtol electric aircraft to enable multirotor vtol electric aircraft recharging;

p. a dual display system comprising an application software operating on a touch-tablet computer or an avionics display system, the dual display system capable of displaying a planned three-dimensional path from origin to destination;

q. an Automatic Dependent Surveillance-B (ADSB) unit configured to provide the avionics display system with collision avoidance, traffic, and weather information to and from the multirotor vtol electric aircraft;

r. a motor management computer or autopilot comprising a computer and input/output interfaces, Controller Area Network (CAN), analog voltage inputs, analog voltage outputs, embedded or stand-alone air data computer capabilities, embedded or stand-alone inertial measurement capability, and a cross-communications channel or network;

s. a DC-DC converter configured to down-regulate motor battery voltage for the multirotor vtol electric aircraft to either 12V or 24/28V standards, with a 12 or 24/28V battery to provide local storage, enabling the battery system to be recharged from one external connector;

t. a throttle to provide a single or dual-redundant variable voltage or potentiometer setting indicative of commanded thrust;

u. a two-axis joystick or control yoke to provide two independent sets of single- or dual-redundant variable voltage or potentiometer settings indicative of pitch command and bank command; and

v. control algorithms operating within the single or redundant motor management computer or autopilot to perform analysis, comparisons, and generate commands to individual motor controllers and monitor results to control the multirotor vertical takeoff and landing (vtol) electric aircraft for transporting multiple occupants and payload.

2. The system of claim 1, further comprising controlling the plurality of electric motors to operate the multirotor vtol electric aircraft within the predetermined performance limitations.

3. The system of claim 1, further comprising systems to operate and control the multirotor vtol electric aircraft within safety, reliability, performance and redundancy measures necessary to protect human life to accepted FAA flight-worthiness standards.

4. The system of claim 1, further comprising use of electric motors for a non-hydrocarbon powered multirotor aircraft with performance and features to meet FAA or international aviation requirements.

5. The system of claim 1, further comprising redundancy features to safely operate and land the multirotor vtol electric aircraft:

a. with one or a pair of motors being inoperative or underperforming;

b. with one or a pair of motor controllers being inoperative or underperforming;

c. with one or more motor management computers or autopilots being inoperative or underperforming;

or

d. with one cross-communication channel or network being inoperative or underperforming.

6. The system of claim 1, further comprising a multiplicity of pancake, axial flux brushless synchronous three-phase AC or DC brushless electric motors.

7. The system of claim 1, further comprising a lightweight upper truss structure that provides mounting attachments for the plurality of motor and propeller subassemblies, and that transfers the lift generated by the plurality of motor and propeller subassemblies to the airframe fuselage, passengers, batteries, payload and electronics.

8. The system of claim 1, further comprising high-voltage, high-current motor controllers capable of up to 100 kW peak performance each that comprises:

a. air-cooling for the removal of waste heat;

or

b. liquid-cooling for the removal of waste heat.

9. The system of claim 1, further comprising a motor that is operated as an aircraft motor.

10. The system of claim 1, further comprising:

a. a propeller or rotor attached to each motor to provide lift or thrust predominantly in a vertical direction;

b. the pairs of motors affixed with propellers or rotors operating in counter-rotating fashion, so as to produce no net torque to the multirotor vtol electric aircraft, and thereby negating a need for a tail rotor.

11. The system of claim 1, further comprising a lightweight outer canopy or shell to protect occupants from airstream and weather while allowing visibility without negating the lift generated by the plurality of motor and propeller assemblies.

12. The system of claim 1, further comprising:

a. multiple series/parallel connected high-energy density, high-current rechargeable battery cells;

b. a Battery Management System (BMS) to monitor and control battery voltage, current, and charge level, and to report status for charging and discharging of the batteries;

c. a recharging system for the multirotor vtol electric aircraft compatible with industry electric vehicle recharging stations;

d. the (BMS) comprises components to recharge the multirotor vtol electric aircraft'"'"'s batteries at the origin, at the destination, or at roadside or rooftop electric vehicle charging stations;

e. the (BMS) comprises components to operate the multirotor vtol electric aircraft in a manned or unmanned mode coupled with a tethered power cable;

or

f. the (BMS) comprises components to use a portion of the multirotor vtol electric aircraft main battery pack to power onboard avionics through a DC-to-DC converter thereby alleviating a need for separate battery chargers or external charging ports.

13. The system of claim 1, wherein the pairs of motors may be commanded to operate at different RPM or Torque settings to produce slightly differing amounts of thrust under the motor management computer or autopilot control, thus imparting a pitch moment, or a bank moment, or a change in altitude, or simultaneously combinations thereof to the multirotor vtol electric aircraft, using position feedback from on-board multi-axis sensors to maintain stable flight attitude.

14. The system of claim 1, wherein multi-axis sensor data is read by each motor management computer or autopilot to assess physical motion and rate of motion, which is then compared to commanded motion in all three axes to determine what new motion is required.

15. The system of claim 1, wherein controlling the plurality of motors comprises:

a. means for maintaining a specified altitude, under command of a thrust lever and the motor management computer or autopilot;

b. means for increasing or decreasing altitude of the multirotor vtol electric aircraft, under command of the thrust lever and the motor management computer or autopilot;

c. means for maintaining a specified pitch and bank angle, under command of the sidearm controller and command of the motor management computer or autopilot;

d. means for changing the pitch and bank angles independently, under command of the sidearm controller and the motor management computer or autopilot;

e. means for allowing the operator to fly a specified origin-to-destination route by following a dual display;

f. means for monitoring available electrical battery capacity to ensure adequate power remains for performing a mission;

g. means for performing motor control algorithms within one to three identical microprocessor-controlled units;

or

h. means for employing voting techniques to arrive at a majority decision for every command, which is a part of providing necessary reliability and safety levels for the system and improving a tolerance to computer, calculation, or system faults.

16. The system of claim 1, wherein the avionics display system for the multirotor vtol electric aircraft comprising interfaces to airspace management resource ADSB capability to:

a. receive broadcast data from other nearby aircraft, and to thereby allow the multirotor vtol electric aircraft to avoid close encounters with other aircraft;

b. broadcast own-aircraft position data to avoid close encounters with the other aircraft;

c. receive weather data for display to the operator and for use by the avionics display system within the multirotor vtol electric aircraft;

d. allow operation of the multirotor vtol electric aircraft with no requirement to interact with or communicate with air traffic controllers; and

e. perform calculations for flight path optimization, based upon own-aircraft state, cooperating aircraft state, efficiency, and available flight path dynamics under a National Airspace System or international systems.

17. The system of claim 1, wherein the multirotor vtol electric aircraft is configured for operation in manned mode or unmanned mode, and where one or more of the position and control instructions when operating in the unmanned mode are performed outside the multirotor vtol electric aircraft, in ground-based equipment, by using a broadband, 802.11 Wi-Fi network or Radio Frequency (RF) bidirectional data-link between the multirotor vtol electric-aircraft and the ground-based equipment,

a. wherein the unmanned mode enables untethered operation in hostile environments or other unmanned applications, subject only to battery capacity and RF or wireless network range;

and

b. wherein the unmanned mode enables unmanned, tethered operation for long-duration surveillance or other missions where a significant payload is desired.

18. A method of providing a full-scale, multirotor vertical takeoff and landing electric aircraft capable of transporting multiple occupants and payload, the method comprising the steps of:

a. providing a multirotor airframe having a plurality of components;

b. providing a physical structure that connects each of the components to each other, capable of supporting a total weight of the multirotor vtol electric aircraft with two or more human passengers;

c. providing a lightweight multirotor upper truss structure that provides mounting attachments for multiple motor and propeller assemblies, and that translates a lift of the multiple motor and propeller assemblies to a mass of the multirotor airframe fuselage, passengers, batteries, and electronics;

d. providing a plurality of the multiple motor and propeller assemblies reliably attached to the lightweight multirotor upper truss structure and connected to the multirotor airframe fuselage, the multiple motor and propeller assemblies each having a plurality of pairs of counter-rotating propellers, and motors being controlled by a plurality of motor controllers;

e. providing the multirotor fuselage with landing skids or wheels to support up to two occupants, avionics and necessary controller electronics and to protect occupants from weather;

f. providing a high energy-density battery system consisting of a plurality of rechargeable battery cells to supply current to the plurality of motor controllers;

g. providing a battery management system to monitor and control charging and discharging of the battery system;

h. the plurality of motor controllers controlling a commanded voltage and torque to each motor and measuring its performance;

i. providing a motor control or autopilot system comprising the plurality of motor controllers or autopilots, where the redundancy provides the safety and reliability required to satisfy safety-of-flight rules;

j. providing communications means comprising serial RS232, Controller Area Network (CAN), or Ethernet interfaces as cross-communications channel or network, channel or network allowing the plurality of motor controllers or the autopilots to share state data and commands for comparison or voting purposes;

k. providing an avionic display system having an interface for receiving broadcast data from other nearby aircraft, and to enable the multirotor vertical takeoff and landing electric aircraft to avoid close encounters with other aircraft;

l. providing the avionic display system having an interface for broadcasting own-aircraft position data to avoid close encounters with the other aircraft;

m. providing the avionic display system having an interface for receiving weather data for display to a pilot and for use by an avionics display system within the multirotor vertical takeoff and landing electric aircraft;

n. providing the avionic display system having an interface for allowing operation of the multirotor vertical takeoff and landing electric aircraft with little or no requirement to interact with or communicate with air traffic controllers; and

o. providing the avionic display system having an interface for performing calculations for flight path optimization and efficiency based upon own-aircraft state, cooperating aircraft state, the other nearby aircraft projected flight paths, and predicted flight path dynamics under the National Airspace System or international airspace management systems; and

controlling the multirotor vertical takeoff and landing (vtol) electric aircraft by a redundant digital Motor Management Computer (MCC) for transporting multiple occupants and payload.

19. The method of claim 18, wherein the method further comprises the steps of:

a. maintaining a specified altitude, under command of a thrust lever and the plurality of motor controllers or the autopilots;

b. increasing or decreasing an altitude of the aircraft, under command of the thrust lever and the plurality of motor controllers or the autopilots;

c. maintaining a specified pitch and bank angle, under command of a sidearm controller and command of the plurality motor controllers or the autopilots;

d. increasing or decreasing pitch and bank angles independently, under command of the sidearm controller and the plurality motor controllers or the autopilots;

e. allowing the pilot to fly a specified origin-to-destination route by following a display presentation by the avionic display system;

f. a battery management system monitoring available electrical battery capacity to ensure adequate power remains for performing a mission; and

g. the MMC performing motor control algorithms within one to three microprocessor-controlled units, and if three units are present, employing voting techniques to arrive at a two-out-of-three decision for every command, thus achieving the necessary reliability and safety requirements for the system and improving the tolerance to computer, calculation, or system faults.