Flying method and system using total energy for an aircraft

Abstract

A flying method using total .[.power.]. .Iadd.energy.Iaddend., in particular for the take-off and overshoot of an aircraft, is disclosed in which the aerodynamic .[∇]. .Iadd.flight path angle .Iaddend.γa is governed by reference to a desired .[∇]. .Iadd.flight path angle .Iaddend.γd which is the .[.total gradient.]. .Iadd.potential flight path .Iaddend.γt modulated by the difference between the aircraft speed V and a reference speed V 2 . An error signal δ representative of the difference between the aerodynamic .[∇]. .Iadd.flight path angle .Iaddend.γa and the desired .[∇]. .Iadd.flight path angle .Iaddend.γd is displayed. The display of the desired .[∇]. .Iadd.flight path angle .Iaddend.γd may be by means of the .[.pitching tendency bar of the artificial horizon.]. .Iadd.pitch command bar of an attitude director indicator .Iaddend.for example.

What is claimed is: 
     
       1. A flying method using total .[.power.]. .Iadd.energy.Iaddend., for an aircraft, and comprising the following steps, governing the aerodynamic .[∇]. .Iadd.flight path angle .Iaddend.γa by reference to a desired .[∇]. .Iadd.flight path angle .Iaddend.γd, obtaining the desired .[∇]. .Iadd.flight path angle .Iaddend.γd by modulating the .[.total gradient.]. .Iadd.potential flight path .Iaddend.γt by the difference between the aircraft speed V and a reference speed V 2 , and displaying an error signal δ representative of the difference between the aerodynamic .[∇]. .Iadd.flight path angle .Iaddend.γa and the desired .[∇]. .Iadd.flight path angle .Iaddend.γd. 
     
     
       2. A flying method according to claim 1, wherein said step of displaying includes displaying said error signal δ by means of the .[.pitching tendency.]. .Iadd.pitch command .Iaddend.bar of an .[.artificial horizon.]. .Iadd.attitude director indicator.Iaddend.. 
     
     
       3. A flying method according to claim 1, and further including calculating the .[.total gradient.]. .Iadd.potential flight path .Iaddend.γt from an accelerometric box. 
     
     
       4. A flying method according to claim 1, and further including calculating the .[.total gradient.]. .Iadd.potential flight path .Iaddend.γt from the speed Vs of the aircraft with respect to the ground, and providing the value of this speed Vs by a central inertial unit. 
     
     
       5. A flying method according to claim 4, and further including calculating γt from the formula: ##EQU4## (g being the acceleration due to gravity), or the formula: ##EQU5## 
     
     
       6. A flying method according to claim 5 and further including governing the derivative dVs/dt by a magnitude proportional to the difference (V-V 2 ) in which V is the aerodynamic speed of the aircraft and V 2  is the reference speed. 
     
     
       7. A flying method according to claim 1, and further including taking into account either the variation δ, intended to subject the speed V to the control of the reference value, or a variation of the .[.stable position.]. .Iadd.pitch attitude .Iaddend.with respect to a reference position, and including transmitting the error signal δ to a .[.comparator.]. .Iadd.voter.Iaddend., comparing δ in the .[.comparator.]. .Iadd.voter .Iaddend.with a signal δ 1  corresponding to said variation of .[.position.]. .Iadd.attitude .Iaddend.and with a constant reference signal δ 2  and controlling the .[.longitudinal tendency.]. .Iadd.pitch command .Iaddend.bar of the .[.artificial horizon.]. .Iadd.attitude director indicator .Iaddend.by the intermediate signal of the group (δ, δ 1 , δ 2 ) i.e. the signal whose instantaneous value is between those of the other two signals. 
     
     
       8. A flying method according to claim 7, and utilizing a reference .[.position.]. .Iadd.attitude .Iaddend.which corresponds to θ 1  =18° and a constant reference signal which corresponds to 20°. 
     
     
       9. A flying method according to claim 1, and utilizing a reference speed of at least two values, (V 2  +10 knots) or V 2 , these two values being interchangeable according to whether the .[.total gradient.]. .Iadd.potential flight path .Iaddend.γt is above or below a calibrated value. 
     
     
       10. A flying method according to claim 9, and utilizing a calibrated value of 6°. 
     
     
       11. A flying method according to claim 1, and including limiting the speed difference signal between positive and negative values. 
     
     
       12. A system for applying a flying method using total .[.power.]. .Iadd.energy.Iaddend., for an aircraft, and comprising the steps of governing the .[.aerodynamic gradient δa.]. .Iadd.flight path angle γa .Iaddend.by reference to a desired .[.gradient δd.]. .Iadd.flight path angle γd.Iaddend., obtaining the desired .[.gradient δd.]. .Iadd.flight path angle γd .Iaddend.by modulating the .[.total gradient δt.]. .Iadd.potential flight path angle γc .Iaddend.by the difference between the aircraft speed .[.B.]. .Iadd.V .Iaddend.and a reference speed V 2 , and displaying an error signal δ representative of the difference between the aerodynamic .[.gradient δa.]. .Iadd.flight path angle γa .Iaddend.and the desired .[.gradient δd.]. .Iadd.flight path angle γd.Iaddend., and wherein a signal representative of the total .[.gradient δt.]. .Iadd.potential flight path angle γc .Iaddend.is transmitted to a first input of an adder which receives at a second input a signal corresponding to the difference between the speed V and a reference speed, the adder output being connected to a first input of a subtractor which receives at a second input, a signal corresponding to the aerodynamic .[.graident δa.]. .Iadd.flight path angle γa.Iaddend., the subtractor output being transmitted to a .[.comparator.]. .Iadd.voter .Iaddend.which is connected to a member for controlling the .[.pitching tendency.]. .Iadd.pitch command .Iaddend.bar of the .[.artificial horizon.]. .Iadd.attitude director indicator.Iaddend., and the .[.comparator.]. .Iadd.voter .Iaddend.also receiving a signal representative of a variation of .[.stable position.]. .Iadd.pitch attitude .Iaddend.and a reference signal. 
     
     
       13. A system according to claim 12, wherein the signal representative of the aerodynamic .[∇]. .Iadd.flight path angle .Iaddend.is provided by a circuit which forms the difference between the .[.stable position.]. .Iadd.pitch attitude .Iaddend.θ 1  and the .[.incidence.]. .Iadd.aerodynamic angle of attack .Iaddend.α, this circuit being able to comprise a commutation device controlled by a signal representing the state of the .[.under-carriage.]. .Iadd.main undercarriage.Iaddend., in order to substitute the .[.stable position.]. .Iadd.pitch attitude .Iaddend.θ 1  for the .[.incidence.]. .Iadd.aerodynamic angle of attack .Iaddend.αwhen said .[.under-carriage.]. .Iadd.main undercarriage .Iaddend.is .[.collapsed.]. .Iadd.compressed.Iaddend., in order to cancel out said difference. 
     
     
       14. A system according to .[.one of.]. claim 12, wherein the signal corresponding to the variation between the speed V and the reference speed comprises a subtractor which subtracts from the speed V, provided by an anemometer, a reference speed V 2 , the subtractor being connected to a first input of a second subtractor, having a second input connected to a source of reference voltage by means of a commutator controlled by a level detector of .[.total gradient.]. .Iadd.potential flight path .Iaddend.γt, the second .[.comparator.]. .Iadd.subtractor .Iaddend.being connected to a non-linear member which serves as a limiter and which provides said speed variation signal. 
     
     
       15. A system according to claim 12, wherein the level detection circuit which operates from the signal γt is composed of a low pass filter connected to an adder by a direct connection and by a derivation circuit comprising a differentiation and filtering member followed by a diode, the output of the adder being connected to a level detector which ensures the control of said commutator. 
     
     
       16. A system according to claim 15, wherein the level detector is adapted to control the non-linear member. 
     
     
       17. A system according to claim 12, wherein the .[.comparator.]. .Iadd.voter .Iaddend.is connected to a member for controlling the .[.pitching tendency.]. .Iadd.pitch command .Iaddend.bar of the .[.artificial horizon.]. .Iadd.attitude director indicator .Iaddend.by means of a limiter. 
     
     
       18. A system according to claim 12, wherein, in order to ensure protection against abnormal negative .[.gradients.]. .Iadd.flight path angle .Iaddend.of the aircraft, due in particlar to poor operation of the flying system circuit providing the signal δ, the input of the .[.comparator.]. .Iadd.voter .Iaddend.corresponding to the signal δ 2  is connected to a circuit providing a signal K (γa-γo), in which K is an adjustment gain and γo is a value representative of a minimum safety .[∇]. .Iadd.flight path angle.Iaddend., below which one should not drop. 
     
     
       19. A system according to claim 12, comprising a detection device serving to detect at the output of the .[.comparator.]. .Iadd.voter .Iaddend.the presence of the signal δ 2  when the latter is selected, and to disconnect the entire flying system when the signal δ 2  remains selected at the end of a predetermined period of time. 
     
     
       20. A system according to claim 12, wherein the input δ 2  of the .[.comparator.]. .Iadd.voter .Iaddend.is connected to an amplifier for an adjustment gain K, which receives the differential signal of a subtractor, which in turn receives a signal representative of the aerodynamic .[∇]. .Iadd.flight path angle .Iaddend.γa and, a signal γo representative of a .[∇]. .Iadd.flight path angle .Iaddend.of predetermined value. 
     
     
       21. A system according to claim 20, wherein the predetermined .[∇]. .Iadd.flight path angle .Iaddend.value is 0.5°. 
     
     
       22. A system according to claim 20, wherein the amplifier for the gain K is connected to a subtractor which also receives the output signal of the .[.comparator.]. .Iadd.voter.Iaddend., and the differential signal provided by said subtractor is transmitted to a logic unit which acts on the .[.flight control horizon.]. .Iadd.attitude director indicator .Iaddend.in order to cause the .[.pitching tendency.]. .Iadd.pitch command .Iaddend.bar to disappear when said differential signal remains zero for a period of time greater.[.,.]. than a predetermined period.