JPH01317898A - Method and device for monitoring state of aircraft - Google Patents

Abstract

PURPOSE: To secure safe navigation when the cutoff of a power system is returned by inputting the feathering uptrim signal into a nonvolatile memory at the time of abnormality detection by means of the condition sensors of an engine and propeller. CONSTITUTION: In a twin turbo-engine propulsion aircraft, the conditions of an engine 32 and a propeller 66 are detected by various sensors 34, 36, and 38, and together with the detected values of the other necessary sensors 48, 50, 52 they are input into a control unit 30. At the time of take-off or the like, the abnormality of the engine 32 is detected, and signals bringing the abnormal engine into the feathering condition and bringing the other engines into uptrim conditions are commanded, and they are input into a nonvolatile memory 74. At the time of abnormality, the electrical system is cut off, and thereafter, when the electrical system is returned by a backup power, the feathering uptrim condition is immediately adopted, so that safe navigation can be continued.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to the monitoring of aircraft engines, particularly during takeoff and
This invention relates to monitoring propeller power to improve aircraft control during landing and other critical flight modes.

BACKGROUND OF THE INVENTION It is desirable for dual-engine aircraft to be able to take off and land on one engine even in the event of failure of one or more engines during flit landings and other critical flight modes. For example, if both engines in a twin-engine turboprop aircraft are operating at approximately 90% of their full rated power (typical fuel-saving operating conditions) and one engine suddenly fails, the failure occurs. Control is improved by automatically feathering the engine and up-trimming a healthy engine. Feathering, for example, reduces drag on a normal aircraft by about 15%, and up-trim increases power by about 10% by increasing the amount of fuel delivered to the engine, which results in an overall increase in power of about 25%. Ru.

However, if one engine fails during takeoff and then the electrical system temporarily fails, the command to feather the failed engine and up-trim the working engine is lost. The feathering and up-trim conditions will not continue even if power is restored. Therefore, the loss of feathering increases effectiveness by about 15%, and the loss of uptrim reduces thrust by about 10%.

DISCLOSURE OF THE INVENTION It is an object of the present invention to improve control during takeoff and landing of multi-engine aircraft.

According to the invention, each engine of a multi-engine aircraft is monitored by one or more sensors corresponding to parameters indicative of the condition of the aircraft.

Also monitored are the aircraft itself and other parameters for controlling the aircraft and engines. The identity of the current state of each engine's automatic feathering system is determined according to state criteria defined as a function of the magnitude of one or more parameter signals from the various sensors. A signal indicating the identity of the current state of each engine's automatic feathering system is stored in non-volatile memory and recalled from the non-volatile memory to control the aircraft propeller according to the identified current state. It will be done. If the identified condition indicates that the engine is not running, action must be taken to feather the inoperable engine and up-trim the remaining good engine.

Depending on the algorithm chosen, the integrity of power to the aircraft control unit is checked continuously or repeatedly, and when a power interruption is detected, the last automatic activation of the engine before power interruption is performed. A non-volatile stored signal indicating the state identity of the feathering device is recalled immediately after power is restored. The called signal is provided for immediate use in controlling the aircraft's propeller in response to the last engine condition identified by the called signal.

For example, suppose a twin-turbo engine prop aircraft takes off with both engines operating, and one engine fails during takeoff mode. The signal processor stores the identity of the feathering state in non-volatile memory, and the aircraft controller feathers the inactive engine and up-trim the remaining healthy engines. Further assume that power is cut off for an indeterminate period of time immediately after one engine fails while the aircraft is in takeoff mode. According to the present invention, the feathering state leading to the feathering command and up-trim command is automatically recalled from non-volatile memory, and the feathering command and up-trim command are lost when power is restored. do not have.

An advantage of the present invention is that flight control is increased by preserving the automatic feathering state during critical flight modes, eliminating the need for backup power or uninterrupted power within the controller. control system cost, size, weight, development time, and power requirements, reducing pilot burden by eliminating the need for the pilot to repeatedly perform feathering and up-trim commands. This includes the reduction of

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be explained in detail below by way of example embodiments with reference to the accompanying figures.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an illustration showing one typical flight profile of a multi-engine aircraft to which the present invention may be usefully applied. The aircraft taxis until it reaches the takeoff point at time tI, and at time t
At l, the altitude increases rapidly until t2, and at time t! ! At , the altitude of the aircraft briefly reaches a constant altitude of 18, after which the altitude is increased again to altitude 20. The flight profile is shown broken to indicate that after this point the aircraft will remain at or near this flight altitude for an extended period of time. Near the high altitude end of the flight profile (e.g. altitude 22), the altitude is at time t
3 to a height 24, and at time t3 the aircraft begins its final descent. The flight ends at t4, at which point the aircraft returns to the ground and begins taxiing.

The period between time tl and every t, i.e. during take-off, and time t
It is desirable to be able to take off or land smoothly even if one engine of a multi-engine aircraft fails during the period between t3 and t4, ie during the final descent of the flight.

To achieve this, several conditions improve flight performance.

For example, if a particular engine fails, it is desirable to automatically feather the propeller of that engine and up-trim the other engines. "Feathering" is the process of aligning the pitch of the propeller in the front and back direction.
Meant to reduce the drag of the failing engine's propeller on the rest of the aircraft, "up-trim" increases the flow of fuel to the normally operating engines, thereby increasing their output power. For example, this means increasing the rated power to the full rated power.

If one engine fails during a critical flight mode such as takeoff or descent, and after engine failure (i.e. the failed engine is controlled under feathering conditions and the other good engine is controlled under up-trim conditions) - If a temporary electrical system failure occurs, the feather command for the failed engine and the up-trim command for other good engines will be lost. It is undesirable for these signals to remain lost even when power is restored. Loss of feathering command increases drag by, for example, about 10% in a twin engine turboprop aircraft, and loss of uptrim decreases thrust by, for example, about 10%.

FIG. 2 is a block diagram illustrating a signal processing device 30 according to the present invention, which is adapted to monitor an aircraft including at least one engine of a multi-engine aircraft. The signal processing device may also be used to monitor other engines, or each of the other engines may be provided with its own signal processing device. The signal processor is responsive to a number of engine sensors 34, 36, . . . 38 and provides a number of corresponding detection signals via lines 40, 42, . It is designed to output . Further, the signal processing device 30 shown in FIG. 2 is provided in the aircraft and receives engine signals, command signals, reference signals, and diagnostic signals inputted to the input/output boat 46 via a corresponding set of signal lines 56, 58, . . . 60. It is designed to respond to a number of other sensors that output .

Those sensors that are not strictly related to actually monitoring the engine 32 are grouped 54 for illustrative purposes.
are grouped as. The signal processing device is also adapted to respond to and output control signals such as interrupts, handshaking, etc. on line 61.

The signal processing device 30 of FIG. 2 generally operates as shown in FIG. 4, FIG. 5, or 6 to maintain a state machine such as, but not limited to, that shown in FIG. A number of logical steps are performed, including but not limited to: Depending on the current state of the engine as determined by the signal processor, the signal processor determines whether the propeller 66 is driven by the engine 32 being monitored.
The feathering command signal for feathering is on line 6.
2 to the feathering actuator 64, and an up-trim command signal is output via line 68 to up-trim one or more normal engines as shown by line 71a. It is determined whether the output is being output to the trim actuator 70 or not.

Conversely, engine 32 may be up-trimmed via similar line 71b in response to one other engine about to fail.

The signal processing device 30 is an electronic engine control device (EEC) commonly used as an aircraft engine controller.
contains part of. The signal processing device includes a random access memory (RAM) 72, a non-volatile memory 74 such as an electrically erasable programmable read only memory (EEFROM) or an electrically programmable read only memory (EAROM), and a central Processing unit (CP)
U) 76 and an input/output port 46, which are connected to each other via a bus 78 that includes functions for transmitting and receiving instruction signals, data signals, designation signals, and control signals. The multiple sensors 48, 50, . . . , 52 described above may be associated with each other as subgroups of the group 54 relating to cockpit commands, such as power lever position, for example. Other sensors may also be associated with other engines and with diagnostic information from other signal processors in the aircraft related to engine condition. The feathering actuator 64 may be part of a propeller control unit (PCU) for the engine 32 being monitored, and the up-trim actuator may be part of an electronic engine control unit (EEC) or fuel control unit for other engines of the aircraft. It may be associated with a control unit (FCU).

It should be noted that signal processing device 30 of FIG. 2 is illustrative of one of the many forms of signal processing device in which the concepts of the present invention may be incorporated.

Thus, although the signal processing device 30 of FIG. 2 is illustrated as a dedicated general purpose digital signal processing device, the concepts of the present invention apply to general purpose signal processing devices, particularly discrete wiring designed for the task described above. It should be noted that the present invention may be implemented in a special purpose digital computer or equivalent analog circuit. Furthermore, the signal processing device 30
The concept of the state machine shown in FIG. Logic steps to be performed as shown in FIG. 4, FIG. 5, or FIG. 6 may be accomplished by other state change diagrams conceptually similar to the state machine shown in FIG. Note that this may be accomplished by monitoring parameters other than those specifically identified herein. In other words, only one embodiment of the present invention is illustrated, and the scope of the claims is not limited by such details.

FIG. 3 is an illustration of a state machine according to the present invention. Three states: standby state 80, arm state 82,
and feathering state 84 are illustrated in FIG. 3, but for reasons that will become apparent later, the states may be changed to only two by merging standby state 80 with arm state 82. In that case, the feathering state 84 is maintained as it is.

The standby state 80 corresponds to the time during the taxi before takeoff and after landing, and thus corresponds to the time before time tI and after time t4 in FIG. 1, and also to the time after time t-!
and t3. These are not critical flight modes and there is no need for the signal processor 30 to maintain an auto-feathering state in accordance with the present invention, and the signal processor may be in a state to accomplish other functions.

States 80, 82, and 84 shown in FIG. 3 transition to each other when a transition criterion is satisfied. Satisfaction of the transition criteria is indicated by a change in one or more of the predetermined FIG. 2 detection signals. In the example of FIG. 3, the transition from standby state 80 to arm state 82 may be within a defined "window" consisting of, for example, the power command lever of the cockbit associated with the desired power level. A similar power lever associated with the other engine of the twin-engine aircraft is detected by sensor 48 of FIG. is detected by mode sensor 52 and indicated by signal line 60, and engine 3
2 is detected by the torque sensor 36 to be generating, for example, 50% or more or other threshold torque.
A similar torque sensor (not shown in FIG. 2, but sensor group 54) of the other engine indicates that the output torque of the other engine is also greater than 50%, as indicated by the magnitude of the torque signal on FIG. The transition line 86 is satisfied by the signal of the sensor (in the sensor). Another criterion is a sensor similar to sensor 34 in FIG. Indicates whether the propeller of the other engine is in a feathering condition so as not to result in a feathering condition, and if the designer falls within the range of transition criteria generally indicated by transition line 86 in FIG. It may be provided by a sensor that outputs a signal indicative of any other desired diagnostic results that one wishes to include.

As mentioned above, the criteria selected may be simple or complex depending on the invention.

When the aircraft is in the armed state 82, it is in a critical flight mode, such as shown in FIG. 1 between times tl and t2 and between times t3 and t4. In addition, when the aircraft is in standby state 80, taxiing or time t in FIG.
: and t3. The difference between these two states is, in some cases, as shown in FIG.
5 or 6 are initiated to be fully executed more often in the arm state 82 than in the standby state 80. This achieves the purpose of freeing up the signal processing device 30 for other tasks when such monitoring is not required in non-critical flight modes.

Once in arm state 82, the aircraft transitions to standby state 80 via transition line 88 or transition line 90.
A transition can be made to the feathering state 84 via the .

A transition from the arm state to the standby state can occur, for example, when the power lever is removed from the "window", or when both engines stop producing torque, when the propeller of the other engine becomes feathered, or when diagnostic results indicate that the arm state is Occurs when conditions are not allowed or even when the aircraft is not in takeoff or descent mode. Each of these conditions is determined by the individual sensors or combinations of sensors described above.

The transition from the arm state 82 to the feathering state 84, indicated by transition line 90, may occur, for example, when the two power levers are in the proper window and the other engine is at approximately 50°C.
% or more of torque, and one engine outputs approximately 2.
Occurs when outputting less than 5% torque, the aircraft is in takeoff or descent mode, and proper diagnostics exist. Any of these signals or other signals, alone or in combination, may be selected by the designer to specify the criteria for transitioning from the arm state to the feathering state.

Once the aircraft is in the feathering condition 84, the signal processing system of FIG. and performs the necessary steps to up-trim the other engine (not shown) as indicated by the up-trim command signal on line 68.

When the aircraft is in a feathering condition 84, as indicated by transition line 92, for example, when both power levers are moved out of a predetermined "window" as indicated by the appropriate sensors in group 54 of FIG. A transition to standby state 80 occurs as shown in FIG.

FIG. 4 shows a simplified sequence of logical steps that may be performed by the signal processing device 30 of FIG. 2 in establishing a state machine such as that shown in FIG. 3 that may accomplish the objectives of the present invention. A flowchart is illustrated. Note, of course, that features illustrated in FIG. 3 as "state machines" are not the same as implying states illustrated as having physical counterparts. The state machine of FIG. 3 is itself only a conceptual mode used by the designer to establish conditions that will initiate desired control actions at appropriate times. In contrast, the signal processor of FIG. 2 becomes such a state machine when programmed according to the logic steps of FIG. 4 constructed using the state change diagram of FIG. The same thing can be said about the flowcharts of FIGS. 5 and 6.

In FIG. 4, after the control flow begins in step 100, step 102 is executed and the input signals 40.42, . . . 44 and 56.58, . is sampled to determine the current magnitude of . These signals are stored in the RAM 72 of the EEC 30, for example. The identity of the current state of the engine is retrieved from a storage location in non-volatile memory, such as EEFROM 74. At least for the time being, EEFRO
Assume that the last save location written to M corresponds to the current state of the engine.

Once the identity of the current state of the engine's automatic feathering device is determined in step 104, step 106 is then executed to check each transition criterion defining a transition from the current state to another state. . If it is determined in the next step 108 that none of the transition criteria are satisfied, the next step 110 is executed, and since the state has not changed, in the case of the run before going through the illustrated routine. A control signal with the same magnitude as , ie without any change, is output to the appropriate actuator, for example via line 62, 68 in FIG.

On the other hand, if it is determined in step 108 that the state transition criterion is satisfied, step 112 is executed before step 110 is executed, and a new state of the automatic feathering device of the engine is determined. The identity is stored in EEFROM 74. Furthermore, the control signal provided in the next executed step 110 may be different than the control signal provided if the transition criteria were not met. Of course, this also applies when the transition is from an arm state to a feathering state or from a feathering state to a standby state.

After step 110 is executed, the process advances to step 114 and the control flow ends.

FIG. 5 is another flowchart illustrating a series of logical steps that may be performed by signal processing device 30 of FIG. 2 in establishing a state machine that may achieve the objectives of the present invention. The control flow begins in step 120, and in the next step 122 the input signals 40, 42, .
. . 44 and 56, 58, . . . 60 are sampled to determine their current magnitude. These signals may be stored in RAM 72 of EEC 30, for example.

Then, in step 124, the engine's current automatic feathering system status is determined according to status criteria established in response to the magnitudes of the various combinations of input parameter signals. In the next step 126 +, a signal is provided indicating the identity of the current state to control the aircraft. For example, if the identity of an engine's current automatic feathering device state is determined to be inactive, the state signal indicates that the engine has failed and causes the failed engine to feather. Appropriate control actions are taken by the aircraft to up-trim.

The status signal is then stored in non-volatile memory in step 128. A determination is then made in step 130 as to whether power is full and is currently being maintained. If power is full, control flow ends at step 132. On the other hand, if the power is not perfect,
In the next step 134, it is determined whether or not power has been restored after the power cutoff was detected in step 130. If a determination is not made that power has been restored, step 134 is executed repeatedly until power is restored. When power is restored, the next step 136 is executed to recall a signal stored in non-volatile memory indicating the last automatic feathering device status of the engine before power was removed.

In the next step 138, the signal invoked is provided as a status signal indicating the current state of the automatic feathering system of the engine to control the aircraft as described above.

FIG. 6 is yet another flowchart illustrating a series of logical steps that may be performed by signal processing device 30 of FIG. 2 in establishing a state machine that can accomplish the objectives of the present invention. It should be noted that any number of other flowcharts that achieve the objectives of the invention may be constructed by those skilled in the art by rearranging, adding, or deleting some steps. Therefore, the scope of the claims should not be construed in the narrow sense indicated by these various flowcharts.

Control flow begins in step 140 and then in step 142 a signal indicating the last saved state of the engine's automatic feathering system is retrieved from non-volatile memory. Then, in step 144, the input signals 40.41, . . . 40 and 56.58 of FIG.
,...60 are sampled to determine their current magnitude.

In the next step 146, the current identity of the engine's automatic feathering device is determined according to the previously established condition criteria.

In a next step 148, the identity of the current state of the engine's automatic feathering device and the identity of the called state are compared, and if there is a difference between them, in a next step 150, the identity of the engine's automatic feathering device is compared. The current state of the automatic feathering device is stored in a non-volatile signal storage medium.

If there is no difference between the above two states or step 1
After the current state of the automatic feathering device of the engine is saved at 50, the next step 152 is performed,
It is determined whether the power has been full or is still being maintained.

If power is full, the next step 154 is executed, which is a call indicating the identity of the current state of the engine automatic feathering system to control the aircraft, as described above in connection with the other flowcharts above. signal is given.

Control flow then ends at step 156.

If it is determined in step 152 that the power is not maintained at full power, the next step 158 is executed to determine whether the power has been restored. If it is determined that power has not been restored, step 158 is repeatedly executed until power is restored. Once a determination is made that power has been restored, the next step 160 is executed and the saved signal indicating the last state before power was interrupted is retrieved. In the next step to be performed, step 154, it is this signal that is provided as an indication of the identity of the current state to control the aircraft. Control flow then ends at step 156.

For methods and means for actually storing status signal information in non-volatile memory, U.S. Pat.
No. 0 describes a method suitable for the present invention (not limited thereto).

Although the present invention has been described above in detail with reference to several embodiments, the present invention is not limited to these embodiments, and various other embodiments are possible within the scope of the present invention. It will be obvious to those skilled in the art that this is the case.

[Brief explanation of the drawing]

FIG. 1 is an illustration showing one typical flight profile for a multi-engine aircraft. FIG. 2 is a block diagram illustrating an engine monitoring and control system for a multi-engine aircraft according to the present invention. FIG. 3 is an illustration showing a state change diagram used in one embodiment of the present invention. FIGS. 4-6 illustrate, for example, a second system for monitoring the states shown in FIG. 3 and saving the identity of these states in non-volatile memory when they occur
2 is a simplified flowchart illustrating a series of logical steps that may be performed by a signal processing device such as that shown. 30... Signal processing device, 32... Engine, 34.
36.38...sensor, 46...input/output port, 4
8.50.52...Sensor, 64...Feathering actuator, 66...Propeller, 70...Up trim actuator, 72...RAM, 74...
・Non-volatile memory, 76...CPU, 78...Bus Patent applicant United Chiknoloshes Corporation Agent Patent attorney Akashi
Takeshi Masa F/G3 F/G, 4

Claims (6)

[Claims] (1) A method of monitoring the state of an aircraft, in which a signal indicating the last state of the aircraft among a plurality of predetermined states is determined from the last written storage location in a non-volatile signal storage medium. and monitoring one or more parameter signals indicative of one or more corresponding sensed parameters associated with said aircraft, each alone or in combination with other parameter signals. said state by checking the fulfillment of one or more state transition criteria defined by at least one parameter signal and corresponding to a defined transition from said last state to one new state other than said last state. a step of verifying that a transition to a new state exists from a last state; a step of storing a signal indicating the identity of the new state after the transition in a non-volatile storage location; and a step of storing a signal indicating the identity of the new state after the transition; A method comprising: providing a control signal according to; (2) a method of monitoring an aircraft, comprising: monitoring one or more parameter signals indicative of one or more corresponding detected parameters associated with the aircraft; determining the identity of the current state of the monitored aircraft according to a state criterion defined in response to the magnitude of a parameter signal; and providing a signal indicative of the identity of the current state for use as a control signal. storing a signal indicative of the identity of the current state in a non-volatile signal storage medium; and testing whether power is present, if restoration of power after power interruption is detected. retrieving a stored signal indicative of the identity of the last state of the engine before the power cutoff; and providing the retrieved signal for use as a control signal. (3) A method for monitoring the state of an aircraft, wherein one of a plurality of predetermined states of the aircraft is selected from the last written storage location in a non-volatile signal storage medium. invoking a signal indicative of a last condition; monitoring one or more parameter signals indicative of one or more corresponding sensed parameters associated with the aircraft; determining the identity of the current state of the monitored aircraft according to a state criterion determined according to the magnitude of the parameter signal and providing a current state signal indicative of the identity; determining whether a transition to a state has occurred and, if the transition exists, storing the current state signal in the non-volatile signal storage medium; and whether power is present. and invoking a stored signal indicating the identity of the last state before the power outage if restoration of power after the power outage is detected; and the recalled signal to be used as a control signal. A method comprising: a process for providing a signal; (4) a device for monitoring the state of an aircraft, the last state of the aircraft being one of a plurality of predetermined states that the aircraft may assume, stored in a non-volatile signal storage medium; signal processing means responsive to stored signals indicative of one or more corresponding sensed parameters associated with said aircraft, each independently or one or more states defined by at least one parameter signal in combination with other parameter signals, each corresponding to a defined transition from said last state to another new state. configured to test for the existence of a transition from said last state to a new state by checking whether one of the transition criteria is satisfied, and to provide a new state signal if a transition exists; An apparatus comprising: signal processing means; and non-volatile signal storage means responsive to a new signal indicative of a new state identity of the monitored aircraft and storing said signal. (5) in an apparatus for monitoring an aircraft, signal processing means responsive to one or more parameter signals indicative of one or more corresponding sensed parameters associated with the aircraft; or more determining the identity of the current state of the monitored aircraft according to a defined state criterion depending on the magnitude of the parameter signal and indicating the identity of the current state for use as a control signal. providing a signal and storing a signal indicative of the identity of the current state in a non-volatile signal storage medium; signal processing means configured to retrieve a stored signal indicative of the identity of the last state of the aircraft and provide the retrieved signal to be used as a control signal; non-volatile signal storage means for storing the signal recalled by the signal processing device in response to the signal. (6) An apparatus for monitoring an aircraft, wherein the aircraft is selected from one of a plurality of predetermined states of the aircraft from the last written storage location in a non-volatile signal storage medium. signal processing means for evoking a signal indicative of a last state of the aircraft, the signal processing means monitoring one or more parameter signals indicative of one or more corresponding sensed parameters relating to said aircraft; determining the identity of the current state of the monitored aircraft according to a state criterion determined according to the magnitude of the parameter signal or more, and providing a current state signal indicative of the identity of the current state; determine whether a transition to the current state has occurred from the state of and configured to invoke a stored signal indicating the identity of the last state before the power interruption if restoration of power after the power interruption is detected and provide the recalled signal as a control signal. a non-volatile signal responsive to the current status signal for storing the current status signal and providing the current status signal on recall as a signal indicative of the last status of the aircraft; a storage means; and an apparatus comprising: