Automated control of the turbomachinery of a rotary-wing aircraft during a turbomachine failure
The automated control of turbomachines during failures in twin-engine aircraft reduces pilot load and errors by using an electronic control unit for power management, maintaining flight safety and power availability.
Patent Information
- Application Number
- FR2022013819
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-12-19
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2042-12-19
AI Technical Summary
Existing manual procedures for managing turbomachine failures in twin-engine aircraft increase pilot load and risk of errors, potentially leading to shutdown of healthy engines.
An automated control method using an electronic control unit to manage turbomachines during failures, involving progressive power adjustments and power limiting to maintain rotation speed and reduce pilot load.
Reduces pilot stress and minimizes errors by automatically managing power reduction on failed engines, ensuring power availability and avoiding excessive use of emergency power regimes.
Smart Images
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Abstract
Description
Title of the invention: Automated control of the turbomachinery of a rotary-wing aircraft during a turbomachine failure technical field
[0001] The present invention relates to the general field of aircraft comprising at least two turbomachines, and more particularly to a control management system for the turbomachines in the event of a fault being detected on one of the turbomachines. Prior art
[0002] Generally, on a twin-engine aircraft or one with more than two turbomachines, when a failure occurs on one of the turbomachines, the pilot is obliged to initiate a manual procedure. This manual procedure consists of idling or shutting down the engine experiencing a failure that could damage it.
[0003] This procedure has the disadvantage of increasing the load on the pilot and generating errors leading to the shutdown of the healthy engine.
[0004] This type of procedure is described in the installation manuals for engines installed on multi-engine helicopter applications, for example. The procedure could be summarized as follows: "In the event of a failure that could damage the engine (low oil pressure, metal shavings, low oil level, clogged filter), it is recommended to immediately put the engine to idle or shut it down." Description of the invention
[0005] To this end, the present invention aims to improve flight safety by reducing pilot workload and in particular by avoiding the use of selectors, which are sources of potential pilot errors.
[0006] In one object of the invention, an automated control method for the turbomachines of a rotary-wing aircraft equipped with a plurality of turbomachines is proposed in the event of a failure on one turbomachine, the method being intended to be implemented by an electronic control unit configured to receive a rotary-wing rotation speed command.
[0007] According to a technical feature of the invention, following the detection of a fault on a first turbomachine among the turbomachines of the rotary-wing aircraft, the automated control method comprises: - a determination of the flight phase in which the aircraft is located, and then, when the aircraft is in a phase other than a takeoff phase, - activation of turbomachinery operation in a misaligned mode via a command for a progressive reduction in the power of said first tur- turbomachine and a control for a progressive increase in the power of at least one second turbomachine of the aircraft, the progressive decrease in power of the first turbomachine and the progressive increase in power of said at least one second turbomachine being controlled in a complementary manner to maintain the rotational speed of the rotary wing at the rotary wing rotational speed setpoint, - activation of an indicator for the pilot, indicating an engine anomaly related to the detected fault, prompting the pilot to use cautious piloting, and - an armament of a power limiter configured to limit the power of the aircraft's turbomachines to a first maximum available power threshold (OEIH) corresponding to a maximum power usable by a turbomachine for a first limited time.
[0008] The rotary wing regime command corresponds to the desired rotary wing rotation speed and generally comes from the avionics which transmits it to the control system, i.e. the electronic control unit.
[0009] The invention thus enables fully automatic management of engine failure scenarios, reducing the pilot load and limiting the risk of errors, while simultaneously ensuring power availability, reducing stress on the failed engine, and limiting the intrusion of healthy engines into emergency power modes. During operation with a failed turbomachine, emergency power modes (OEIH, OEIL, OEIC), i.e., modes beyond a certain threshold, are referred to as OEI modes, for "One Engine Inoperative." More specifically, there is the OEIH mode for a high speed, the OEIL mode for a low speed, and the OEIC mode for continuous operation.For example, the OEIH regime may be an accessible regime for 30 seconds while the EYE regime is an accessible regime for 2 minutes, and the OEIC regime is continuously accessible, the OEIH regime being higher than the EYE regime itself being higher than the OEIC regime.
[0010] Indeed, the method according to the invention improves flight safety during a turbomachine failure through automatic management of power reduction on the failed engine, in order to reduce its damage while prioritizing power availability, and limiting incursions into the OEI regimes of other engines, in order to avoid heavy maintenance operations.
[0011] The process implemented by an automated system reduces the pilot load and the risk of incorrect decisions (particularly shutdown of a healthy engine), while maintaining the "spirit" of standard recommendations (pilot habits). This automated system is activated when faults that could lead to engine damage are detected and reported to the system. Typically, this involves Failures in the oil circuit. The system then automatically manages the power reduction on the faulty engine in order to limit damage and automatically compensates with the other engines.
[0012] The method of the invention has as its basic principle replacing the pilot's management of engine failure situations with fully automated management by an electronic control unit for engine monitoring and control. This applies in particular to cases of oil system failures and provides automatic management ensuring both power availability, reduced stress on the failed engine, and limitation of the other engines' entry into operating condition. Thus, the proposed invention aims to reduce the pilot's workload while retaining the main principles of the management initially implemented when these functions were performed manually by the pilots.
[0013] In a first embodiment of the method according to the invention, a takeoff phase is detected when the power delivered by at least one turbomachine is greater than a continuous maximum power threshold.
[0014] In a second embodiment of the method according to the invention, the method may further include, before activating operation of the turbomachines in a misaligned mode, a check of the operating status of all the turbomachines, the misaligned mode being kept inactive if a failure impacting the nominal operation of at least one turbomachine is also detected on at least one of the turbomachines.
[0015] During nominal operation of a turbomachine, the safety of the turbomachine is ensured, and there is no risk that its integrity will be affected.
[0016] The expression "a failure impacting nominal operation" refers to a failure that prevents the safe operation of an aircraft turbomachine. A failure impacting the nominal operation of a turbomachine could be, for example, a failure of sensors or actuators.
[0017] In a third embodiment of the method according to the invention, the progressive decrease in the power of said first turbomachine and the progressive increase in the power of at least one second turbomachine of the aircraft are carried out until the power of the first turbomachine reaches a lower power limit, the power of said at least one second turbomachine remaining below a second maximum available power threshold (OEIL), or until the power of said at least one second turbomachine reaches the second maximum available power threshold (OEIL), the power of said first turbomachine having a value greater than said lower power limit of the first turbomachine.
[0018] In a fourth embodiment of the method according to the invention, if, following the activation of operation of the turbomachines in a misaligned mode, a pilot issues a request for a power increase, the method includes a command to increase the power of said at least one second turbomachine up to, at most, a second maximum available power threshold (OEIL), and, if the increase in the power of said at least one second turbomachine is insufficient for the turbomachines to develop in total the power required by the pilot, a command to increase the power of said first turbomachine up to, at most, the second maximum available power threshold (OEIL), the power increase on said at least one second turbomachine and, if necessary, on said first turbomachine being carried out for a limited time.
[0019] However, if the rotating wing speed setpoint cannot be reached in this way, the power increase on the turbomachines remains possible up to the first maximum available power threshold (OEIH).
[0020] In a fifth embodiment of the method according to the invention, the pilot commands an arming of a power limiter to limit the power of the aircraft's turbomachines to a second maximum available power threshold (OEIL) corresponding to a maximum power usable by a turbomachine for a second limited time greater than the first limited time, the second maximum available power threshold (OEIL) being less than the first maximum available power threshold (OEIH).
[0021] In a sixth embodiment of the method according to the invention, if, following the activation of operation of the turbomachines in a misaligned mode, a pilot issues a request for a power increase, the method includes a command to increase the power of said at least one second turbomachine up to, at most, a third maximum available power threshold (OEIC) lower than the second maximum available power threshold (OEIL), and, if the power increase of said at least one second turbomachine is insufficient for the turbomachines to develop in total the power required by the pilot, a command to increase the power of said first turbomachine up to, at most, the third maximum available power threshold (OEIC), the power increase on said at least one second turbomachine and, if necessary, on said first turbomachine being able to be carried out for an unlimited duration.
[0022] However, if the rotating wing speed setpoint cannot be reached in this way, the power increase on the turbomachines remains possible up to the second maximum available power threshold (OEIL).
[0023] According to another object of the invention, an electronic control unit is proposed for a rotary-wing aircraft equipped with a plurality of turbomachines, The electronic control unit is configured to receive a rotation speed command for the rotor blades and to automatically control the aircraft's turbomachinery in the event of a turbomachine failure; the electronic control unit comprises: - an input module configured to receive signals detecting a failure on the first turbomachine among the turbomachines of the rotary-wing aircraft, - a means for determining the flight phase of the aircraft, - a means for activating the operation of the turbomachines in a misaligned mode configured to deliver, when the aircraft is in a phase other than a takeoff phase, a command for a gradual decrease in the power of said first turbomachine and a command for a gradual increase in the power of at least one second turbomachine of the aircraft, the gradual decrease in power of the first turbomachine and the gradual increase in power of said at least one second turbomachine being controlled in a complementary manner to maintain the rotary-wing speed at the set rotary-wing speed, and - a means of activating an engine fault indicator for the pilot, prompting them to use cautious piloting techniques, and - a means of arming a power limiter configured to limit the power of the aircraft's turbomachines at least to a first maximum available power threshold (OEIH) corresponding to a maximum power usable by a turbomachine for a first limited time.
[0024] The rotary wing regime command corresponds to the desired rotary wing rotation speed and generally comes from the avionics which transmits it to the control system, i.e. the electronic control unit.
[0025] According to another object of the invention, a rotary-wing aircraft is proposed comprising at least two turbomachines and an electronic control unit. Brief description of the drawings
[0026] [Fig-1] Figure [Fig.1] illustrates a method for the automated control of turbomachinery of a rotary-wing aircraft during a turbomachine failure according to an implementation method.
[0027] [Fig.2] Figure [Fig.2] illustrates a method for the automated control of turbomachinery of a rotary-wing aircraft during a turbomachine failure according to a second implementation method.
[0028] [Fig.3] Figure [Fig.3] illustrates an automated control method for turbomachinery of a rotary-wing aircraft during a turbomachine failure according to a third embodiment of the invention.
[0029] [Fig.4] Fig.4 schematically presents an electronic control unit tronic according to an embodiment of the invention.
[0030] [Fig. 5] Fig. 5 graphically represents the evolution of the operating speeds of the two turbochargers. aircraft machinery when the process of [Fig.1] is implemented.
[0031] [Fig.6] Fig.6 graphically represents the evolution of the operating conditions of the two turbo- aircraft machinery when the process of [Fig.1] is implemented while the aircraft is in the takeoff phase when a failure is detected.
[0032] [Fig.7] Fig.7 graphically represents the evolution of the operating conditions of the two turbo- aircraft machinery when the process of [Fig.2] is implemented. Description of the implementation methods
[0033] Figure 1 illustrates a flowchart of an automated control method for the turbomachines of a rotary-wing aircraft during a failure on a turbomachine according to an implementation method of the invention, the method being intended to be implemented by an electronic control unit.
[0034] The aircraft comprising an electronic control unit implementing such a method is a rotary-wing aircraft, such as a helicopter, comprising at least two turbomachines for the operation of the rotary wing.
[0035] In the examples illustrated in Figures 1 to 7, the configuration consists of only two turbomachines. However, the invention also applies if there is more than one second turbomachine, the first being the one that has failed.
[0036] The automated control method according to the invention is implemented following the detection of a fault in a first turbomachine of the aircraft. The fault may correspond, for example, to a fault in oil pressure or an excessively high oil temperature, or other faults of the same level of severity; in other words, faults that do not involve a shutdown of the turbomachine's operation, but nevertheless require the turbomachine to operate in a degraded mode to preserve its integrity. These faults can indeed cause damage to the turbomachine if its operation is maintained under excessively demanding conditions.
[0037] Following the detection of an oil pressure fault, for example, the automated control method according to the invention illustrated in [Fig. 1] first comprises, in a first step 100, a check of the operating status of all the aircraft's turbomachines. If a fault affecting nominal operation is detected on at least one of the turbomachines, the method according to the invention is aborted; otherwise, it proceeds to the next step 102.
[0038] Then in a subsequent step 102, the process includes a determination of the phase flight path in which the aircraft is located.
[0039] If a takeoff phase is detected in the first step 102, in particular by detecting power delivered by at least one turbomachine exceeding a maximum continuous power threshold, the subsequent steps of the process are not carried out. This continues until the takeoff phase is completed, as indicated in step 104, and as illustrated in [Fig. 6], which will be described later.
[0040] When the aircraft is in a phase other than a takeoff phase, the method according to the invention achieves, in a step 110, an activation of the operation of the turbomachines in a misaligned mode, and, at the same time, in a step 120, an activation of an indicator, for the pilot, of the activation of the misaligned mode, inviting the pilot to use cautious piloting.
[0041] As illustrated in [Fig. 5], which graphically represents the evolution of the operating speeds of the two turbomachines of an aircraft when the method of [Fig. 1] is implemented, a delay is used between the detection of the oil pressure fault and the activation of the misaligned mode in step 110. This delay is used to ensure that the aircraft is not in a takeoff phase even though the power speed of the turbomachines is lower than the maximum continuous power (MCP) speed, which represents the lower threshold of the maximum takeoff power (MTP) range.
[0042] Figure 6 graphically represents the evolution of the operating speeds of the two turbochargers. The aircraft's engines are affected when the procedure in [Fig. 1] is implemented while the aircraft is in the takeoff phase and a fault is detected. In [Fig. 6], the fault is detected while the turbomachinery power speed is within the PMD range. The procedure in [Fig. 1] is not activated as described in step 104. The pilot must wait for a reduction in turbomachinery power speed below a threshold value before the timer is initiated and the misaligned mode is automatically activated at the end of the timer period if the power speed is still below this threshold.
[0043] The threshold in question corresponds to a turbomachinery power regime strictly below the limit associated with the aircraft's maximum continuous power (MCP). For safety, a margin of a few percent below the MCP is used to set this threshold.
[0044] As illustrated in Figures 5 and 6, and in [Fig.1], step 110 of activating an operation of the turbomachines in a misaligned mode includes, in a step 112, a command for a progressive decrease in the power of the first turbomachine, Engine 1, and, in a step 114 simultaneous with step 112, a command for a progressive increase in the power of the second turbomachine, Engine 2.
[0045] At the same time, in a step 130 following step 110, the electronic control unit arms a power limiter configured to limit the power of the aircraft's turbomachines (Engine 1 and Engine 2) to a first maximum available power threshold, called the high maximum power threshold (OEIH), corresponding to a maximum power usable by a turbomachine for a first limited time.
[0046] The progressive decrease in power of the first turbomachine and the progressive increase in power of the second turbomachine are controlled in a complementary manner to maintain the rotational speed of the rotating wing at the rotational speed setpoint of the rotating wing.
[0047] As shown in step 116 in [Fig. 1], the progressive decrease in the power of the first turbomachine and the progressive increase in the power of the second turbomachine are carried out: - either until the power of the first turbomachine (denoted PI on [Fig.l]) reaches a lower power limit of the first turbomachine (denoted Lim on [Fig.l] and lower limit on figures 5 and 6), the power of the second turbomachine remaining below a second maximum available power threshold (OEIL), - either until the power of the second turbomachine (noted P2 on [Fig.l]) reaches the second maximum available power threshold (noted EYE on [Fig.l]), the power of the first turbomachine then having a value greater than the lower power limit of the first turbomachine.
[0048] Figure 2 illustrates a method according to a second embodiment of the invention. Figure 7 graphically represents the evolution of the operating conditions of the two turbomachines of an aircraft when the method of Figure 2 is implemented.
[0049] As illustrated in [Fig. 2], if, following the activation of turbomachinery operation in a misaligned mode, a pilot issues a power increase request in step 140 (labeled A in [Fig. 7]), the method further includes, in step 142, a command to increase the power of the second turbomachine (Engine 2) up to, at most, the second maximum available power threshold (OEIL), as indicated in step 144. And, if the power increase of the second turbomachine is insufficient for the turbomachinery to develop a total (labeled P in [Fig. 2]) of the power required by the pilot, the method further includes, in step 146 (labeled B in [Fig. 7]), an increase in the power of the first turbomachine (Engine 1) up to, at most, the second maximum available power threshold (OEIL), as indicated in step 148. the [Fig.2]. On the [Fig.7], the total power required by the pilot developed by the two engines is reached at stage C. The power increase on the second tur- . bomachine and, if necessary, on the first turbomachine being carried out for a limited time as indicated in step 150.
[0050] However, if the rotating wing speed setpoint cannot be reached in this way, the power increase on the turbomachines remains possible up to the first maximum available power threshold (OEIH).
[0051] On [Fig.7], the AEO operating level corresponds to the classic operating level of the two turbomachines (AEO).
[0052] Figure 3 illustrates a method according to a third embodiment of the invention.
[0053] As illustrated in [Fig.3], the pilot can command, in a step 160, an arming of a power limiter to limit the power of the aircraft's turbomachines to a second maximum available power threshold (OEIL) corresponding to a maximum power usable by a turbomachine for a second limited time greater than the first limited time, the second maximum available power threshold (OEIL) being less than the first maximum available power threshold (OEIH).
[0054] In such a case, if, following the activation of operation of the turbomachines in a misaligned mode, a pilot issues, in a step 240, a request for a power increase, the method further includes, in a step 242, a command to increase the power of said at least one second turbomachine up to, at most, a third maximum available power threshold (OEIC) lower than the second maximum available power threshold (OEIL), as indicated in step 144. And, if the power increase of said at least one second turbomachine is insufficient for the turbomachines to develop in total the power required by the pilot, the method further includes an increase, in step 246, of the power of said first turbomachine up to, at most, the third maximum available power threshold (OEIC), as indicated in step 248.
[0055] In this configuration, the power increase on the second turbomachine and, if necessary, on said first turbomachine can be carried out without time limit.
[0056] However, if the rotating wing speed setpoint cannot be reached in this way, the power increase on the turbomachines remains possible up to the second maximum available power threshold (OEIL).
[0057] Figure 4 schematically illustrates an electronic control unit according to one embodiment of the invention.
[0058] The electronic control unit 1 is configured to automatically control the turbomachinery of a multi-engine rotary-wing aircraft during a failure on a turbomachine.
[0059] The electronic control unit 1 includes an input module 2 configured to receive signals detecting a failure on a first turbomachine among the turbomachines of the rotary-wing aircraft, a means 3 for determining the flight phase of the aircraft, and a means 4 for activating misaligned operation of the turbomachines. The means 4 for activating misaligned operation of the turbomachines is configured to deliver, when the aircraft is in a phase other than a takeoff phase, a command for a gradual decrease in the power of said first turbomachine and a command for a gradual increase in the power of at least one second turbomachine of the aircraft.The progressive decrease in power of the first turbomachine and the progressive increase in power of said at least one second turbomachine are controlled in a complementary manner to maintain the rotational speed of the rotor at the rotational speed setpoint of the rotor.
[0060] The electronic control unit further includes a means 5 for activating an engine fault indicator for the pilot, prompting him to use cautious piloting, and a means 6 for arming a power limiter allowing selection of either the second maximum available power threshold (OEIL) or the third maximum available power threshold (OEIC) or a return to the first maximum available power threshold (OEIH) previously automatically selected following entry into misaligned mode.
[0061] The method according to the invention thus provides a technical solution for improving flight safety by reducing pilot workload and in particular by avoiding the use of selectors, which are sources of potential pilot errors.
Claims
Claims
1. Method for automated control of the turbomachines of a rotary wing aircraft provided with a plurality of turbomachines during a failure on a turbomachine, the method being intended to be implemented by an electronic control unit configured to receive a rotation speed setpoint of the rotary wing, characterized in that, following detection of a failure on a first turbomachine among the turbomachines of the rotary wing aircraft, the automated control method comprises: - a determination (102) of the flight phase in which the aircraft is located, then, when the aircraft is in a phase other than a takeoff phase, - an activation (110) of an operation of the turbomachines in a misaligned mode via a command (112) of a progressive reduction in the power of said first turbomachine and a command (114) of a progressive increase in the power of at least one second turbomachine of the aircraft,the progressive decrease in power of the first turbomachine and the progressive increase in power of said at least one second turbomachine being controlled in a complementary manner to maintain the rotation speed of the rotary wing at the rotation speed setpoint of the rotary wing, - an activation (120) of an indicator, for the pilot, of an engine anomaly relating to the detected failure inviting him to use prudent piloting, and - an arming (130) of a power limiter configured to limit the power of the turbomachines of the aircraft to a first maximum available power threshold (OEIH) corresponding to a maximum power usable by a turbomachine for a first limited duration.,
2. Automated control method according to claim 1, in which a take-off phase is detected when the power delivered by at least one turbomachine is greater than a maximum continuous power threshold.
3. Automated control method according to one of claims 1 or 2, further comprising, before activating an operation of the turbomachines in a misaligned mode, a verification (100) of the operating state of all turbomachines, the misaligned mode being kept inactive if a failure impacting the nominal operation of at least one turbomachine is detected.
4. Automated control method according to one of claims 1 to 3, wherein the progressive reduction in the power of said first turbomachine and the progressive increase in the power of at least one second turbomachine of the aircraft are carried out until the power of the first turbomachine reaches (116) a low power limit, the power of said at least one second turbomachine remaining below a second maximum available power threshold (OEIL), or until the power of said at least one second turbomachine reaches the second maximum available power threshold (OEIL), the power of said first turbomachine having a value greater than said low power limit of the first turbomachine.
5. Automated control method according to one of claims 1 to 4, wherein if, following the activation of operation of the turbomachines in a misaligned mode, a pilot issues a request for an increase in power (140), the method comprises a command (142) for increasing the power of said at least one second turbomachine up to, at most, a second maximum available power threshold (OEIL), and, if the increase in the power of said at least one second turbomachine is insufficient for the turbomachines to develop in total the power required by the pilot, a command (146) for increasing the power of said first turbomachine up to, at most, the second maximum available power threshold (OEIL), the increase in power on said at least one second turbomachine and, if necessary, on said first turbomachine being carried out for a limited duration (150).
6. Automated control method according to one of claims 4 or 5, in which the pilot commands an arming (160) of a power limiter to limit the power of the aircraft's turbomachines to a second maximum available power threshold (OEIL) corresponding to a maximum power usable by a turbomachine for a second limited duration greater than the first limited duration, the second maximum available power threshold (OEIL) being lower than the first maximum available power threshold (OEIH).
7. An automated control method according to claim 6, wherein if, following activation of operation of the turbomachines in a
8. misaligned mode, a pilot issues a request (240) for an increase in power, the method comprises a command (242) for increasing the power of said at least one second turbomachine up to, at most, a third maximum available power threshold (OEIC) lower than the second maximum available power threshold (OEIL), and, if the increase in the power of said at least one second turbomachine is insufficient for the turbomachines to develop in total the power required by the pilot, a command (246) for increasing the power of said first turbomachine up to, at most, the third maximum available power threshold (OEIC), the increase in power on said at least one second turbomachine and, if necessary, on said first turbomachine being able to be carried out for an unlimited duration. Electronic control unit (1) for a rotary wing aircraft having a plurality of turbomachines, the electronic control unit (1) being configured to receive a rotation speed setpoint of the rotary wing and to automatically control the turbomachines of the aircraft in the event of a failure on a turbomachine, the electronic control unit (1) comprising: - an input module (2) configured to receive signals for detecting a failure on a first turbomachine among the turbomachines of the rotary wing aircraft, - a means (3) for determining the flight phase in which the aircraft is located, - a means (4) for activating an operation of the turbomachines in a misaligned mode configured to deliver, when the aircraft is in a phase other than a takeoff phase, a command for a progressive reduction in the power of said first turbomachine and a command for a progressive increase in the power of at least one second turbomachine of the aircraft, the progressive reduction in power of the first turbomachine and the progressive increase in power of said at least one second turbomachine being controlled in a complementary manner to maintain the rotation speed of the rotary wing at the rotation speed at a rotation speed setpoint of the rotary wing, - a means (5) for activating an indicator of an engine anomaly for the pilot inviting him to use cautious piloting, and - a means (6) for arming a power limiter configured to
9. limit the power of the aircraft's turbomachines to at least a first maximum available power threshold (OEIH) corresponding to a maximum power usable by a turbomachine for a first limited duration. Rotary wing aircraft comprising at least two turbomachines and an electronic control unit according to claim 8.