Clean fuel electric multirotor aircraft for personal air transportation and manned or unmanned operation

• US 9,764,822 B2
• Filed: 04/29/2015
• Issued: 09/19/2017
• Est. Priority Date: 05/01/2014
• 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): Bonzell, Philip J
• Application Number:
  US14/699,945
• Publication Number:
  US 20160200421A1
• Time in Patent Office: 874 Days
• CPC Class Codes: B64C 13/18 using automatic pilot
• CPC Class Codes: B64C 27/08 with two or more rotors
• CPC Class Codes: B64D 2041/005 Fuel cells
• CPC Class Codes: B64D 27/026 comprising different types of power plants, e.g. combination of a piston engine and a gas-turbine Hybrid electric aircraft B64D27/33
• CPC Class Codes: B64D 27/24 using steam or spring force jet aircraft B64D27/16
• CPC Class Codes: B64U 10/17 Helicopters flying platforms B64U10/13
• CPC Class Codes: B64U 2101/60 for transporting passengers; for transporting goods other than weapons
• CPC Class Codes: B64U 2201/20 Remote controls
• CPC Class Codes: B64U 50/19 using electrically powered motors
• CPC Class Codes: B64U 50/32 generated by fuel cells
• CPC Class Codes: B64U 70/90 Launching from or landing on platforms
• CPC Class Codes: G01C 23/00 Combined instruments indicating more than one navigational value, e.g. for aircraft; Combined measuring devices for measuring two or more variables of movement, e.g. distance, speed or acceleration
• CPC Class Codes: G05D 1/0077 using redundant signals or controls
• CPC Class Codes: Y02T 50/40 Weight reduction
• 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
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

Methods and systems for a full-scale vertical takeoff and landing manned or unmanned aircraft, having an all-electric, low-emission or zero-emission lift and propulsion system, an integrated ‘highway in the sky’ avionics system for navigation and guidance, a tablet-based motion command, or mission planning system to provide the operator with ‘drive by wire’ style direction control, and automatic on-board-capability to provide traffic awareness, weather display and collision avoidance. Automatic computer monitoring by a programmed triple-redundant digital autopilot computer controls each motor-controller and motor to produce pitch, bank, yaw and elevation, while simultaneously restricting the flight regime that the pilot can command, to protect the pilot from inadvertent potentially harmful acts that might lead to loss of control, or loss of vehicle stability. By using the results of the state measurements to inform motor control commands, the methods and systems contribute to the operational simplicity, reliability and safety of the vehicle.

Claims

1. A full-scale, multirotor all-electric aircraft system sized, dimensioned, and configured for transporting one or more human occupants and payload, the system comprising:

a multirotor airframe fuselage, having a structure supporting the total vehicle weight together with the one or more human occupants and payload;

a multirotor upper truss structure connected to the multirotor airframe fuselage;

a plurality of motor and propeller assemblies attached to the multirotor upper truss structure, the plurality of motor and propeller assemblies each comprising a plurality of pairs of counter-rotating propeller blades, the plurality of motor and propeller assemblies being controlled by a plurality of motor controllers;

an electrical power-generating system comprising one of;

a hydrogen fuel-cell system comprising a hydrogen storage tank, a plurality of fuel cell subsystems, one or more air-driven turbochargers supplying compressed air to the plurality of fuel cell subsystems, and a plurality of fuel cells supplying voltage and current to the plurality of motor controllers, wherein the hydrogen fuel-cell system combines hydrogen from the hydrogen storage tank with compressed air to generate electrical voltage and current;

or

a motor-generator system comprising a fuel storage tank, one or more hydrocarbon-fueled motors, and a plurality of motor-driven high voltage generators to supply current to said multirotor motor controllers;

a power distribution and circuit breaker subsystem autonomously monitoring and controlling distribution of the generated electrical voltage and current to the plurality of motor controllers and an avionics system; and

wherein the plurality of motor controllers are commanded by one or more autopilot control units, where the one or more autopilot control units control the commanded electrical voltage and torque or current for each of the plurality of motor and propeller assemblies and track the rotations per minute (RPM) and the torque produced or the current consumed at each of the plurality of motor and propeller assemblies.

2. The system of claim 1, wherein a source of power for the plurality of motor and propeller assemblies further comprises one or more hydrogen-powered fuel-cells or hydrocarbon-fueled motors with diode or field-effect transistor (FET) isolation between each electrical source and an electrical main bus and the one or more hydrogen-powered fuel-cells or hydrocarbon-fueled motors, where each engine is fueled by compressed natural gas (CNG), liquefied petroleum gas (LPG), or aviation standard fuel (avgas) and each fuel cell is powered by hydrogen or other suitable gaseous fuel.

3. The system of claim 1, further comprising controlling the plurality of motor and propeller assemblies to operate the multirotor all-electric aircraft system within predetermined aircraft performance limitations.

4. The system of claim 1, further comprising landing skids or wheels connected to the multirotor airframe fuselage supporting the multirotor all-electric aircraft system.

5. The system of claim 1, wherein the multirotor all-electric aircraft system is controlled within safety, reliability, performance, and redundancy measures necessary to protect human life to accepted FAA flight-worthiness standards.

6. The system of claim 1, wherein the plurality of motor controllers are high-voltage, high-current air-cooled or liquid-cooled controllers configured for up to 100 kW peak performance minimum.

7. The system of claim 1, wherein the multirotor all-electric aircraft system is operable autonomously and wherein some or all of the position and control instructions are performed outside the multirotor all-electric aircraft system, by using a broadband or 802.11 Wi-Fi network or Radio Frequency (RF) bidirectional data-link between the multirotor all-electric aircraft system and ground-based equipment.

8. The system of claim 1, wherein the multirotor all-electric aircraft system is operable autonomously and wherein some or all of the position and control instructions are performed inside the multirotor all-electric aircraft system, by using mission planning software to designate a route, destination, and altitude profile for the multirotor all-electric aircraft system to fly, forming the flight plan for that flight to be performed without human involvement.

9. The system of claim 1, wherein the electrical power-generating system further comprises multiple high-current battery cells mounted within modular enclosures of the multirotor airframe fuselage that require periodic charging while not in flight, comprising:

a battery management system configured to monitor battery voltage, current, charge, and status of the multiple high-current battery cells; and

a recharging system compatible with automotive electric vehicle recharging stations, according to J1772 standards;

wherein the multiple high-current battery cells are configured to recharge the multirotor aircraft'"'"'s batteries at an origin, at a destination, or at roadside EV charging stations;

wherein the multiple high-current battery cells are configured to operate the multirotor all-electric aircraft system in a manned or unmanned local surveillance mode when ‘

tethered’

by a power cable; and

wherein the electrical power-generating system uses a portion of the main generated power of the multirotor all-electric aircraft system to power onboard avionics through a DC-to-DC converter or starter-alternator, thereby alleviating a need for separate charger and charge-ports for batteries powering the onboard avionics.

10. The system of claim 1, further comprising:

an On/Off key connected to a high-current contactor that isolates the electrical power-generating system from the plurality of motor and propeller assemblies when power from the electrical power-generating system is not required;

a mission display system that displays to an operator information about a state of performance metrics of the electrical power-generating system;

a motor-enable safety switch providing a means of disabling and enabling the plurality of motor and propeller assemblies;

an external refueling connector compatible with infrastructure for electric powered vehicles, to enable aircraft system refueling;

a dual display system comprising software operating on a touch-tablet computer or avionics display system;

a dual mission controller tablet computer comprising the software operating on the touch-tablet computer or the avionics display system, with wired or wireless (RF) connections to the one or more autopilot control units;

a wirelessly connected or wire-connected Automatic Dependent Surveillance-Broadcast (ADSB) unit providing the software with collision avoidance, traffic, and weather information to and from the multirotor all-electric aircraft system;

one or more autopilot control units comprising a single-board computer and input/output interfaces comprising at least one of the following interfaces;

serial RS232, Controller Area Network (CAN), Ethernet, analog voltage inputs, analog voltage outputs, pulse-width-modulated outputs for motor control, an embedded or stand-alone air data computer, an embedded or stand-alone inertial measurement device, and one or more cross-communication channels or networks;

a DC-DC converter or starter/alternator configured to down-shift at least a portion of a primary voltage of the multirotor all-electric aircraft system to either 24V or 28V standards for avionics and non-motor purposes, with a 24V or 28V battery to provide local current storage;

a tablet computer operating mission software, or a throttle or foot control pedal, providing a variable voltage or potentiometer setting indicative of commanded thrust;

a tablet computer operating mission software, or a 2-axis joystick or control yoke, providing two independent sets of variable voltage or potentiometer settings indicative of pitch command and bank command;

a means of combining pitch, roll, yaw, throttle, and other desired information onto a serial line, using servo controls, in such a way that multiple channels of command data pass from tablet to the one or more autopilot control units over the serial line, where control information is packaged in a plurality of frames that repeat at a periodic rate;

the one or more autopilot control units operating control algorithms generating commands to each of the plurality of motor controllers, managing and maintaining vehicle stability, and monitoring feedback.

11. The system of claim 10, wherein the avionics display system for the multirotor all-electric aircraft system comprises an interface to the ADSB unit, operable to:

receive broadcast data from nearby aircraft;

transmit desired state information to the one or more autopilot control units to avoid collisions with the nearby aircraft;

the one or more autopilot control units determine an action to command to avoid the collisions with the nearby aircraft;

broadcast position data of the multirotor all-electric aircraft system to the nearby aircraft to provide the nearby aircraft with the position information to avoid potential collisions;

receive weather data and display the weather data on the avionics display system;

enable operation of the multirotor all-electric aircraft system with no requirement to interact with or communicate with air traffic controllers; and

perform calculations for flight path optimization and collision avoidance, based upon a state of the multirotor all-electric aircraft, states of the nearby aircraft, and available flight path dynamics under the National Airspace System or equivalent systems in other countries.

12. The system of claim 1, wherein the plurality of motor and propeller assemblies comprise pancake, axial flux brushless synchronous three-phase AC or DC electric motors.

13. The system of claim 12, wherein the plurality of motor and propeller assemblies are an aircraft motor.

14. The system of claim 12, wherein the plurality of motor controllers and propeller assemblies provide lift or thrust forces predominantly in a vertical direction.

15. The system of claim 12, wherein pairs of propellers operate in counter-rotating fashion, so as to produce no net torque to the multirotor all-electric aircraft system, in such a way that a tail rotor is not necessary for stabilized and controlled rotary aircraft operation.

16. The system of claim 15, wherein pairs of the plurality of motor and propeller assemblies operate at different RPM or Torque settings to produce slightly differing amounts of thrust under computer control, thereby imparting a pitch moment, or a bank moment, or a yaw moment, or a change in altitude, or simultaneously combinations thereof, to the multirotor all-electric aircraft system, using position feedback from on-board inertial, atmospheric, global positioning system (GPS), and magnetic sensors to maintain flight stability.

17. A method for implementing an advanced fault tolerant control of a multirotor all-electric aircraft, comprising:

receiving, by at least one valid autopilot computing device communicating over a redundant network, a route or position command set from dual redundant pilot control tablets;

translating, by each available valid autopilot computing device of the at least one valid autopilot computing device, the received route or position command set into output commands to control multiple motor controllers, the translating comprising using control algorithms to generate the output commands for each of the multiple motor controllers;

voting on the output commands to be transmitted to the multiple motor controllers, by each of the at least one autopilot computing device, the voting comprising determining which of a majority of the output commands of the available valid autopilot computing device are in agreement; and

automatically transmitting the output commands determined majority vote to the multiple motor controllers.

18. The method as claimed in claim 17, wherein the method further includes the steps of:

receiving broadcast data from nearby aircraft;

transmitting new output commands to the available valid autopilot computing devices to avoid collisions with the nearby aircraft;

broadcasting position data of the multirotor all-electric aircraft to the nearby aircraft;

receiving weather data and displaying weather data on an avionics display system within the multirotor all-electric aircraft;

enabling operation of the multirotor all-electric aircraft without requiring interaction with or communication with air traffic controllers; and

performing calculations for flight path optimization and collision avoidance, based upon a state of the multirotor all-electric aircraft, states of the nearby aircraft, and available flight path dynamics under the National Airspace System.

19. A method for automated flight control and mission planning for operating a multirotor all-electric aircraft, comprising:

a plurality of autopilot computing devices receiving, from a tablet computing device, a route or position command set, comprising at least one of physical motion and command detected by the tablet computing device or a pre-planned mission route pre-programed into the tablet computing device;

the plurality of autopilot computing devices measuring and/or receiving multirotor all-electric aircraft real-time state information;

the plurality of autopilot computing devices translating the received route or position command set and the real-time state information into outputs to control multiple motor controllers of the multirotor all-electric aircraft;

the plurality of autopilot computing devices transmitting the outputs to the multiple motor controllers;

the plurality of autopilot computing devices measuring and/or receiving updated multirotor all-electric aircraft real-time state information;

the plurality of autopilot computing devices automatically assessing whether a new route or position command set is needed to maintain stability of the multirotor all-electric aircraft based on the updated real-time state information; and

the plurality of autopilot computing devices transmitting a new route or position command set to the multiple motor controllers.

20. The method of claim 19, further comprising:

maintaining a specified altitude of the multirotor all-electric aircraft, under command of the tablet computing device and the plurality of autopilot computing devices;

increasing or decreasing an altitude of the multirotor all-electric aircraft, under command of the tablet computing device and the plurality of autopilot computing devices;

maintaining a pitch, bank, and yaw angle of the multirotor all-electric aircraft, under command of the tablet computing device and the plurality of autopilot computing devices;

increasing or decreasing the pitch, bank, and yaw angles independently under command of the tablet computing device and the plurality of autopilot computing devices;

allowing an operator to fly a specified origin to destination route by following a display presentation;

allowing the operator or an unmanned vehicle to fly a pre-programmed origin to destination route and elevation profile by following a pre-programmed mission profile;

monitoring available electrical and fuel capacity to ensure available flight path dynamics adequate power remains for performing a flight to the specified origin to destination or the pre-programmed origin to destination; and

performing motor control algorithms within the plurality of autopilot computing devices.

21. The method of claim 20, wherein the real-time state information further comprises reading sensor data and assessing physical motion and rate of motion by each of the plurality of autopilot computing devices to be compared to commanded motion in all three dimensions to assess whether the new route or position command set is needed.

22. The method of claim 20, wherein the plurality of autopilot computing devices comprise a plurality of autopilot computing devices and employ voting node techniques to arrive at a majority decision for performing the motor control algorithms, thereby achieving reliability and safety requirements for the multirotor all-electric aircraft and improving fault tolerance.