Method of managing a power demand for the operation of a pilotless aircraft equipped with an internal combustion engine

• US 9,677,466 B2
• Filed: 12/11/2015
• Issued: 06/13/2017
• Est. Priority Date: 12/16/2014
• Status: Active Grant

• Current Assignee: Airbus Group SAS (Airbus SE)
• Original Assignee: Airbus Group SAS (Airbus SE)
• Inventors: Smaoui, Hichem, Rechain, Bruno, Retho, Fabien
• Primary Examiner(s): Troost, Aaron L
• Application Number:
  US14/966,180
• Publication Number:
  US 20160167799A1
• Time in Patent Office: 550 Days
• CPC Class Codes: B60K 6/24 characterised by the combustion engines
• CPC Class Codes: B60K 6/387 Actuated clutches, i.e. clutches engaged or disengaged by electric, hydraulic or mechanical actuating means
• CPC Class Codes: B60K 6/40 characterised by the assembly or relative disposition of components
• CPC Class Codes: B60K 6/442 Series-parallel switching type
• 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: B64U 10/20 Vertical take-off and landing [VTOL] aircraft flying platforms B64U10/13; helicopters B64U10/17
• CPC Class Codes: B64U 50/11 using internal combustion piston engines
• CPC Class Codes: B64U 50/12 using turbine engines, e.g. turbojets or turbofans
• CPC Class Codes: B64U 50/19 using electrically powered motors
• CPC Class Codes: F01D 15/10 Adaptations for driving, or combinations with, electric generators
• CPC Class Codes: F02B 33/40 of non-positive-displacement type
• CPC Class Codes: F02B 37/00 Engines characterised by provision of pumps driven at least for part of the time by exhaust
• CPC Class Codes: F02B 65/00 Adaptations of engines for special uses not provided for in groups F02B61/00 or F02B63/00; Combinations of engines with other devices, e.g. with non-driven apparatus of rotary-piston or oscillating-piston engines F02B53/14; combinations of prime-movers consisting of electric motors and internal combustion engines for mutual or common propulsion B60K6/20
• CPC Class Codes: F02C 6/12 Turbochargers, i.e. plants for augmenting mechanical power output of internal-combustion piston engines by increase of charge pressure
• CPC Class Codes: F02C 6/14 Gas-turbine plants having means for storing energy, e.g. for meeting peak loads
• CPC Class Codes: F02C 6/206 the vehicles being airscrew driven
• CPC Class Codes: F05D 2220/329 in helicopters
• CPC Class Codes: F05D 2220/40 in turbochargers
• CPC Class Codes: F05D 2220/62 with energy recovery turbines
• CPC Class Codes: F05D 2220/76 an electrical generator
• CPC Class Codes: F05D 2220/90 : in vehicles adapted for vertical or short take off and landing (v/stol vehicles)
• CPC Class Codes: F05D 2260/42 : Storage of energy
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 50/60 : Efficient propulsion technologies, e.g. for aircraft

Abstract

A method of managing a power demand to assure the operation of a pilotless aircraft. The aircraft includes an internal combustion engine supplying a maximum principal power which can vary. The management method is particularly suitable for a rotary wing pilotless aircraft. It guarantees the storage of an amount of electrical energy at least equal to a recovery energy of the aircraft in the event of failure of the internal combustion engine. This recovery energy enables the control of autorotation and landing of the aircraft.

Claims

1. Method of managing a power demand to assure operation of a pilotless aircraft, the aircraft comprising an internal combustion engine supplying a maximum principal power P_M, which can vary, the method comprises the steps of, in the absence of an internal combustion engine failure:

a) collecting at least some of exhaust gases during an operation of the internal combustion engine;

b) feeding a turbine with an energy of the exhaust gases collected;

c) producing an electrical current using an electrical generator connected to the turbine to generate an electrical energy;

d) comparing the maximum principal power P_M supplied by the internal combustion engine with a demanded power P_D at a time of the power demand;

e) in response to a determination that the maximum principal power P_M is at least equal to the demanded power P_D for an operation of the pilotless aircraft, performing at least one of storing at least some of the electrical energy generated in at least one energy storage unit and utilizing said at least some of the electrical energy generated to assist the internal combustion engine by supplying an auxiliary power P_A complementing a main power P_t developed by the internal combustion engine, with P_t less than P_M, so that P_A+P_t=P_D;

f) in response to a determination that the maximum principal power P_M is less than the demanded power P_D for the operation of the pilotless aircraft, utilizing said at least some of the electrical energy generated to assist the internal combustion engine to provide the demanded power P_D or utilizing at least some of the electrical energy stored in said at least one energy storage unit to assist the internal combustion engine to supply the demanded power P_D;

g) in response to a determination that the demanded power P_D is greater than the sum of the maximum principal power P_M developed by the internal combustion engine and the auxiliary power that can be supplied by said at least one energy storage unit, modifying the operation of the pilotless aircraft to supply the demanded power P_D in accordance with one of the steps e) or f); and

h) in response to a determination that the pilotless aircraft is on the ground and the internal combustion is stopped, supplying the demanded power P_D to the pilotless aircraft utilizing said at least some of the electrical energy stored in said at least one storage unit.

2. Method according to claim 1, wherein the step of utilizing said at least some of the electrical energy stored in said at least one energy storage unit to assist the internal combustion engine in step e), further comprises the step of feeding at least one of a compressor of the internal combustion engine and an electric motor developing an auxiliary power P_A.

3. Method according to claim 1, wherein the pilotless aircraft is a rotary wing aircraft;

and further comprising the step of regulating the stored electrical energy to be at least equal to a recovery energy of the pilotless aircraft in the event of the internal combustion engine failure.

4. Method according to claim 3, wherein the pilotless aircraft comprises N electrical energy storage units, with N>

1; and

further comprising the step of adjusting a capacity of a first storage unit to be less than or equal to a threshold value Vs/N where Vs corresponds to the recovery energy of the pilotless aircraft in the event of the internal combustion engine failure, in response to a determination, in step f), that a sum of remaining capacities in other N−

1 storage units is greater than or equal to Vs.

5. Method according to claim 1, before the steps e) and f), further comprising the step determining a state of charge for each energy storage unit.

6. Method according to claim 5, wherein the pilotless aircraft is a rotary wing aircraft comprising N electrical energy storage units, with N>

1; and

further comprising the step of adjusting a capacity of a first storage unit to be less than or equal to a threshold value Vs/N where Vs corresponds to a recovery energy of the pilotless aircraft in the event of the internal combustion engine failure, in response to a determination, in step f), that a sum of remaining capacities in other N−

1 storage units is greater than or equal to Vs.

7. Method according to claim 1, wherein the pilotless aircraft is a rotary wing aircraft comprising at least two rotors;

and further comprising the step of disengaging a mechanical coupling of each rotor to assure a free rotation of said at least two rotors and an autorotation of the pilotless aircraft in an event of the internal combustion engine failure.

8. Method according to claim 7, further comprising the step of supplying a demanded power to the pilotless aircraft to control a descent in the autorotation and landing of the pilotless aircraft in the event of the internal combustion engine failure utilizing said at least some of the electrical energy stored in said at least one storage unit.

9. Method according to claim 7, further comprising the step of automatically disengaging the mechanical coupling of said each rotor in the event of a stoppage of the internal combustion engine.

10. Method according to claim 9, further comprising the step of supplying a demanded power to the pilotless aircraft to control a descent in the autorotation and landing of the pilotless aircraft in the event of the internal combustion engine failure utilizing said at least some of the electrical energy stored in said at least one storage unit.

11. Method according to claim 1, wherein the step of modifying the operation of the pilotless aircraft comprises at least one of the following actions:

reducing an altitude of the pilotless aircraft and modifying a speed of the pilotless aircraft.

12. Rotary wing pilotless aircraft, comprising:

a supercharged internal combustion engine to drive a rotary wing system, the internal combustion engine comprises a first compressor, the internal combustion engine is configured to drive the rotary wing system and to supply a maximum principal power, which can vary, to assure at least the driving of the rotary wing system; and

a recovery system to recover a thermal energy and convert the recovered thermal energy into an electrical energy, the recovery system comprises a collector to collect at least some of exhaust gases during an operation of the internal combustion engine, a turbine fed with the exhaust gases collected to convert an energy of the exhaust gases collected into a mechanical energy; and

an electrical generator fed by the turbine to produce an electrical energy;

at least one energy storage unit configured to store at least some of the electrical energy produced by the recovery system;

a propulsion control unit configured to determine a maximum principal power P_M supplied by the internal combustion engine at the time of a power demand P_D and to manage generation of the electrical energy to meet the power demand as a function of the power demand to at least drive the rotary wing and the maximum power supplied by the internal combustion engine;

wherein in response to a determination that the maximum principal power P_M is at least equal to the power demand P_D for an operation of the rotary wing pilotless aircraft, the propulsion control unit is configured to control at least one of the following;

said at least one energy storage unit to store at least some of the electrical energy generated by the electrical generator, and the recovery system to utilize said at least some of the electrical energy generated by the electrical generator to assist the internal combustion engine by supplying an auxiliary power P_A complementing a main power P_t developed by the internal combustion engine, with P_t less than P_M, so that P_A+P_t=P_D;

wherein in response to a determination that the maximum principal power P_M is less than the power demand P_D for the operation of the rotary wing pilotless aircraft, the propulsion control is configured to control the recovery system to utilize said at least some of the electrical energy generated by the electrical generator to assist the internal combustion engine to provide the power demand P_D, or said at least one energy storage unit to supply the auxiliary power P_A to assist the internal combustion engine in supplying the power demand P_D;

wherein in response to a determination that the power demand P_D is greater than the sum of the maximum principal power P_M developed by the internal combustion engine and the auxiliary power that can be supplied by said at least one energy storage unit, the propulsion control unit is configured to modify the operation of the rotary wing pilotless aircraft to supply the power demand P_D; and

wherein in response to a determination that the rotary wing pilotless aircraft is on the ground and the internal combustion is stopped, the power demand P_D is supplied to the rotary wing pilotless aircraft utilizing said at least some of the electrical energy stored in said at least one storage unit.

13. Rotary wing pilotless aircraft according to claim 12, wherein the internal combustion engine comprises a second compressor configured to be fed with the electrical energy from said at least one energy storage unit.

14. Rotary wing pilotless aircraft according to claim 12, further comprising a main gearbox connected to the internal combustion engine, and an electric motor configured to be fed with the electrical energy from said at least one energy storage unit, the electric motor is connected to the main gearbox.

15. Rotary wing pilotless aircraft according to claim 12, further comprising at least two rotors and a device to disengage a mechanical coupling of each rotor to assure a free rotation of said at least two rotors in an event of an internal combustion engine failure.

16. Rotary wing pilotless aircraft according to claim 12, further comprising a system to manage a state of charge of each energy storage unit to have available at all times a recovery energy of the rotary wing pilotless aircraft in the event of an internal combustion engine failure.