Patent Description:
Modem aircraft increasingly incorporate automation to facilitate the task of operators and to reduce the risk of operator error. Some examples of automation in aircraft include roll control for facilitating roll-neutral yawing, thrust-based propeller blade scheduling, and the like. In some cases, the automation of these functions leads to a reduction in the amount of actions which need to be performed by the operator.

The automation systems developed in recent years have been deployed primarily in turbofan-powered aircraft, where a singular system controls the operation of each turbofan powerplant. In contrast, turbopropeller-powered aircraft typically use separate control systems for controlling the operation of the engine and the propeller. The dual nature of the control systems used in turbopropeller-powered aircraft complicates the implementation of automation.

As such, there is room for improvements.

Prior art includes <CIT>, <CIT> and <CIT>.

In accordance with a broad aspect of the invention, there is provided a method for controlling autothrottle of an engine for a turbopropeller-powered aircraft, as claimed in claim <NUM>.

In an embodiment according to any of the previous embodiments, the method further comprises: determining a target position for the manual input based on at least one of the digital power request and an operating parameter of the engine; transmitting the target position to an actuator coupled to the manual input to cause the manual input to adopt the target position.

In an embodiment according to any of the previous embodiments, the method further comprises detecting a change in the operating parameter of the engine; determining a subsequent target position for the manual input based on the operating parameter of the engine; and transmitting the subsequent target position to actuator coupled to the manual input to cause the manual input to adopt the subsequent target position.

In an embodiment according to any of the previous embodiments, the method further comprises evaluating an autothrottle readiness condition for the engine based on an operating parameter of the engine; and when the autothrottle readiness condition is met, producing an autothrottle readiness alert for an operator of the engine.

In an embodiment according to any of the previous embodiments, the digital power request is obtained in response to the autothrottle readiness alert being provided.

In an embodiment according to any of the previous embodiments, the manual input is a power lever, and wherein the manual input mode is based on a power lever angle of the power lever.

In an embodiment according to any of the previous embodiments, controlling the engine based on the digital power request comprises: determining, based on the digital power request, a requisite engine power and a requisite propeller rotational speed for achieving a power level satisfying the digital power request; causing the engine to produce power commensurate with the requisite engine power; and causing a propeller associated with the engine to rotate at a speed commensurate with the requisite propeller rotational speed.

In an embodiment according to any of the previous embodiments, wherein the autothrottle input comprises an indication of a target airspeed.

In an embodiment according to any of the previous embodiments, the method further comprises producing a confirmation indication following the engaging.

In accordance with another broad aspect, there is provided a system for controlling autothrottle of an engine as claimed in claim <NUM>.

In an embodiment according to any of the previous embodiments, the program instructions are further executable for: determining a target position for the manual input based on at least one of the digital power request and an operating parameter of the engine; transmitting the target position to an actuator coupled to the manual input to cause the manual input to adopt the target position.

In an embodiment according to any of the previous embodiments, the program instructions are further executable for: detecting a change in the operating parameter of the engine; determining a subsequent target position for the manual input based on the operating parameter of the engine; and transmitting the subsequent target position to actuator coupled to the manual input to cause the manual input to adopt the subsequent target position.

In an embodiment according to any of the previous embodiments, the program instructions are further executable for: evaluating an autothrottle readiness condition for the engine based on an operating parameter of the engine; and when the autothrottle readiness condition is met, producing an autothrottle readiness alert for an operator of the engine.

In an embodiment according to any of the previous embodiments, the program instructions are further executable for producing a confirmation indication following the engaging.

With reference to <FIG>, an aircraft <NUM> is illustrated, having a fuselage <NUM>, a pair of wings <NUM> (or more), engines <NUM>, propellers <NUM>, and a tail <NUM>. The aircraft <NUM> may be any suitable aircraft - such as corporate, private, commercial, or the like - which includes multiple engines <NUM> and propellers <NUM>. Collectively, an engine-propeller pair may be referred to as a "powerplant". The aircraft <NUM> may be a fixed wing or a rotary wing aircraft. The fuselage <NUM> has a cockpit <NUM>, which can be positioned at any suitable location on the aircraft <NUM>, for example at a front portion of the fuselage <NUM>. The cockpit <NUM> is configured for accommodating one or more operators who control the aircraft <NUM> by way of one or more operator controls. The operator controls can include any suitable number of pedals, yokes, steering wheels, centre sticks, flight sticks, levers, knobs, switches, and the like. Although two engines <NUM> are illustrated, it should be understood that the aircraft <NUM> can have any suitable number of engines, for example three, four, six, eight, and the like.

The engines <NUM> effect rotational motion in the propellers <NUM>, which in turn produce thrust via propeller blades, causing the aircraft <NUM> to be displaced. The propellers blades are configured for assuming a propeller blade angle, which varies the thrust produced by the propellers <NUM>. The propeller blade angle is indicative of an orientation of the blades of the propellers <NUM> relative to a particular reference angle. For example, a positive propeller blade angle can cause the propellers <NUM> to produce forward thrust, that is to say, thrust which displaces the aircraft <NUM> in a direction aligned with the heading of the aircraft <NUM>. Conversely, a negative propeller blade angle can cause the propellers <NUM> to produce reverse thrust, which is substantially opposite positive thrust.

In certain circumstances, for example during cruise portions of a flight mission, it can be desired to engage automatic control of part or all of the operation of powerplants of the aircraft <NUM>, including of the engines <NUM> and/or the propellers <NUM>. Automatic control of the engines <NUM> can be referred to as "autothrottle", and involves at least automatic control of a level of fuel flow to the engines <NUM>. Autothrottle can also involve control of other operating parameters of the engines <NUM>, including air intake and bleed, orientation of variable geometry mechanisms, and the like. In embodiments in which the aircraft <NUM> includes the propellers <NUM>, the autothrottle can additionally control a rotational speed of the propellers <NUM>.

With reference to <FIG>, there is illustrated a block diagram of an example autothrottle system <NUM> for an aircraft, for example the aircraft <NUM>. The autothrottle system <NUM> is composed of an autothrottle controller <NUM> and a digital interface <NUM>. Although illustrated here as separate components, it should be understood that in some embodiments, the autothrottle controller <NUM> and the digital interface <NUM> can be implemented via a single entity, for example any suitable digital control components. The aircraft <NUM> additionally includes an engine controller <NUM>, for controlling operation of the engine <NUM>, a propeller controller <NUM>, for controlling operation of the propeller <NUM>, as well as a manual input <NUM>, to which is coupled an actuator <NUM>, and an autothrottle input <NUM>.

The manual input <NUM> allows an operator of the aircraft <NUM> to provide an indication of a desired power setting for the engine <NUM>. The manual input <NUM> can be a power lever, a pedal, or a similar device, and a power setting for the engine <NUM> can be represented as a power lever angle, a position of the pedal, and the like. In some embodiments, the manual input <NUM> is an analog input device. In some cases, the power lever is provided with a plurality of settings, including a maximum takeoff setting, a flight idle setting, a ground idle setting, and a reverse thrust setting, each associated with respective power lever angles. The manual input <NUM> can provide a signal to the engine controller <NUM>, which indicates the power lever angle, and the engine controller can interpret the signal to determine one or more engine settings for the engine <NUM>. In some embodiments, the manual input <NUM> also allows the operator to provide an indication of a desired rotational speed for the propeller <NUM>. In other embodiments, the rotational speed for the propeller <NUM> is scheduled or otherwise defined as a function of the power setting for the engine <NUM>. In still further embodiments, the manual input <NUM> can be one of many inputs, and can include a separate input for controlling operation of the propeller <NUM>, including setting a desired rotational speed for the propeller <NUM>. Still other embodiments are considered.

The autothrottle input <NUM> allows an operator of the aircraft <NUM> to indicate that an autothrottle mode of operation for the powerplants of the aircraft <NUM> should be engaged. In many embodiments, the autothrottle mode is engaged for all powerplants of the aircraft <NUM> substantially simultaneously, and the particular control commands then issued to the powerplants may vary between powerplants. In some embodiments, the autothrottle mode controls operation of the engine <NUM> and the propeller <NUM>, for example via the engine and propeller controllers <NUM>, <NUM>. In other embodiments, the autothrottle mode controls operation of the engine <NUM>, for example via the engine controller <NUM>, and operation of the propeller <NUM>, via the propeller controller <NUM>, can be effected via the engine controller <NUM>. Still other implementations of an autothrottle mode are considered. The autothrottle input <NUM> can be implemented via any suitable input device. In some embodiments, the autothrottle input <NUM> is a button or other binary control. In other embodiments, the autothrottle input <NUM> includes a selection input via which a particular setting for the autothrottle control can be selected, for example a cruise speed or other airspeed, a rate of fuel expenditure, and the like. Still other implementations of the autothrottle input <NUM> are considered. For example, the autothrottle input <NUM> can be part of a flight computer of the aircraft <NUM>.

The engine controller <NUM> and the propeller controller <NUM> are configured to control operation of the engine <NUM> and the propeller <NUM>, respectively. The engine controller <NUM> can be implemented using a full-authority digital electronic controller (FADEC) or similar digital control device. The propeller controller <NUM> can be implemented using a propeller electronic control (PEC) or similar digital control device. In operation, the engine controller <NUM> obtains a power request for the engine <NUM> from the manual input <NUM>, which can be a power lever angle. The engine controller <NUM> can then issue various commands to engine <NUM> and to the propeller controller <NUM>, which in turn can issue commands to the propeller <NUM>. In this fashion, the operating parameters of the engine <NUM> and the propeller <NUM> can be altered to produce output power commensurate with the power request issued via the manual input <NUM>, or via other inputs, as described hereinbelow, for example from the autothrottle system <NUM>.

The autothrottle controller <NUM> is communicatively coupled to the manual input <NUM>, to the autothrottle input <NUM>, to the digital interface <NUM>, and to the actuator <NUM>. The autothrottle controller <NUM> can obtain, from the manual input <NUM>, an indication of the power setting for the engine <NUM>, for instance the aforementioned power lever angle. In addition, autothrottle controller <NUM> is configured for obtaining, from the autothrottle input <NUM>, a request to engage the autothrottle mode (referred to herein as "autothrottle request"), and optionally one or more settings for the autothrottle mode.

In response to obtaining the autothrottle request, the autothrottle controller <NUM> can command the digital interface <NUM> to produce a digital power request for transmission to the engine controller <NUM>. In some embodiments, the autothrottle controller <NUM> and/or the digital interface <NUM> translate the information provided as part of the autothrottle request into a requisite power setting for the engine <NUM>, for example using any suitable algorithm, scheduling table, lookup table, and the like.

The digital interface <NUM> is communicatively coupled to autothrottle controller <NUM> for obtaining the command to produce the digital power request, and to the engine controller <NUM> for providing the engine controller <NUM> with the digital power request. In some embodiments, the digital interface <NUM> includes a digital concentrator. In other embodiments, the digital interface <NUM> includes an analog-to-digital converter (ADC). The digital interface <NUM> can receive an analog power request from the autothrottle controller <NUM>, and can convert the analog power request into a digital power request for transmission to the engine controller <NUM>. Still other implementations are considered, and the digital interface <NUM> can produce the digital power request using any suitable protocols, interfaces, and can communicate the digital power request using any suitable wired and/or wireless media.

In this fashion, the autothrottle request obtained via the autothrottle input <NUM> is communicated to the engine controller <NUM> as a digital power request, provided by the digital interface <NUM>. The digital power request bypasses the manual input <NUM>, and the engine controller <NUM> can then control the engine <NUM>, and in some cases the propeller <NUM>, via the propeller controller <NUM>, based on the digital power request. Put differently, when the autothrottle mode is engaged, the manual input <NUM>, which can be an analog input device, is not used to control the operation of the engine <NUM> and/or the propeller <NUM>. Instead, the engine <NUM> and/or the propeller <NUM> are controlled via a digital input, namely that provided via the digital interface <NUM>.

When the engine controller <NUM> receives the digital power request, the engine controller <NUM> first terminates a pre-existing control mode for the engine <NUM>. The pre-existing control mode can, for example, be based on the manual input <NUM>, and can be referred to as a "manual input mode". Once the manual input mode has been terminated, the autothrottle mode for the engine <NUM> can be engaged, wherein the engine <NUM> is controlled based on the digital power request obtained by the engine controller <NUM> from the digital interface <NUM>.

In some embodiments, when the engine controller <NUM> engages the autothrottle mode in response to the digital power request, the engine controller <NUM> determines a requisite power for the engine <NUM> for achieving a power level satisfying the digital power request. Additionally, in some cases, the engine controller <NUM>, or the propeller controller <NUM>, also determines a requisite propeller rotational speed for the propeller <NUM> for achieving the power level satisfying the digital power request. Once the requisite power for the engine <NUM>, and optionally the requisite propeller rotational speed for the propeller <NUM>, are determined, the engine controller <NUM> and/or the propeller controller <NUM> cause the engine <NUM> and the propeller <NUM> to operate commensurately with the requisite power for the engine <NUM> and propeller rotational speed for the propeller <NUM>.

In order to determine the requisite power for the engine <NUM>, and optionally the requisite propeller rotational speed for the propeller <NUM>, the engine controller <NUM> and/or the propeller controller <NUM> can be provided with any suitable thrust conversion algorithms for determining the appropriate operating parameters for the engine <NUM> and/or the propeller <NUM>. In some embodiments, the engine controller <NUM> and/or the propeller controller <NUM> are provided with various information about the operating conditions of the engine <NUM> and/or the propeller <NUM>, including factors for determining aircraft drag, and the like.

In some other embodiments, the autothrottle system <NUM> determines a requisite thrust level for the powerplant(s) of the aircraft <NUM>, including the thrust contributions of both the engine <NUM> and the propeller <NUM>. In one example, the autothrottle system <NUM> can then determine, based on the requisite thrust level, a requisite power level for the engine <NUM> and a requisite rotational speed for the propeller <NUM>. The digital interface <NUM> can then communicate to the engine controller <NUM> optionally the propeller controller <NUM> respective digital power and rotational speed requests. Alternatively, the digital interface <NUM> can communicate a digital thrust request to the engine controller <NUM>, which can contain both the digital power request for the engine <NUM> and a digital rotational speed request for the propeller <NUM>. The engine controller <NUM> can then provide the digital rotational speed request to the propeller <NUM>. The digital thrust request can be provided to the engine controller <NUM> in any suitable fashion, for example substantially similarly to the way in which the digital power request is provided to the engine controller <NUM>.

In another example, the autothrottle system <NUM> provides the engine controller <NUM> with a digital thrust request, and the engine controller <NUM> is configured for determining, based thereon, a requisite power level for the engine <NUM> and a requisite rotational speed for the propeller <NUM>. This can include producing a digital power request, used within the engine controller <NUM>, and optionally a digital rotational speed request, which can be provided to the propeller controller <NUM>. In this example, the engine controller <NUM> can be provided with any suitable number of schedules, lookup tables, algorithms, and the like, for determining the appropriate requisite power level and rotational speed for the engine <NUM> and the propeller <NUM>, respectively, based on the digital thrust request. Alternatively, the autothrottle system <NUM> can provide schedules, lookup tables, algorithms, and the like, as needed to the engine controller <NUM>. Still other approaches are considered.

In addition, the autothrottle system <NUM> can obtain, for example via the digital interface <NUM>, information regarding changes in operating conditions of the engine <NUM> and/or of the propeller <NUM>. Changes in operating conditions can include changes in ambient temperature, ambient pressure, altitude, airspeed, and the like. In response to these changes, the autothrottle system <NUM> is configured for issuing a subsequent digital power request to adjust the operation of the engine <NUM> and/or the propeller <NUM>, via the engine controller <NUM> and/or the propeller controller <NUM>, in order to align the operation of the engine <NUM> and/or the propeller <NUM> with the autothrottle request obtained from the autothrottle input <NUM>.

In some embodiments, the engine controller <NUM> is configured for reporting to the autothrottle system <NUM>, for instance via the digital interface <NUM>, an autothrottle readiness condition for the engine. The autothrottle readiness condition can be indicative of whether the engine <NUM> and/or the propeller <NUM> are operating in a state suitable for engaging the autothrottle mode. In some embodiments, the autothrottle controller <NUM> can provide an autothrottle readiness alert to an operator of the aircraft <NUM>, for example via the autothrottle input <NUM>, that the autothrottle readiness condition is met. For instance, the autothrottle input <NUM> can be provided with a lamp or other visual indicator, which can be actuated when the autothrottle readiness condition is met. In another instance, the autothrottle input <NUM> can produce an audible chime or other audible indicator when the autothrottle readiness condition is met. Still other approaches for reporting the autothrottle readiness condition to the operator of the aircraft <NUM> are considered. In some embodiments, the autothrottle request is obtained in response to providing the autothrottle readiness alert to the operator of the aircraft <NUM>.

Alternatively, or in addition, the autothrottle system <NUM> can produce a confirmation indication for the operator of the aircraft <NUM> once the autothrottle mode is engaged. The confirmation indication can be provided via the visual indicator, the audible indicator, or any other suitable system. For example, the confirmation indication can be displayed on a screen of a flight computer of the aircraft <NUM>. In some embodiments, the confirmation indication can also include other information regarding the autothrottle mode, including a current airspeed of the aircraft, a fuel expenditure rate for the aircraft, and the like.

The autothrottle controller <NUM> is configured for adjusting the manual input <NUM> based on the digital power request produced by the digital interface <NUM>. For example, in cases in which the autothrottle request results in a significant change in the power produced by the engine <NUM>, a mismatch between the actual power level of the engine <NUM> and the power level which would be requested if the engine <NUM> were controlled based on the manual input <NUM> results. By adjusting the manual input <NUM> based on the digital power request, a transition from the autothrottle mode to another flight mode, for example the manual input mode, can be performed more smoothly, reducing a so-called "thrust bump". In some embodiments, adjustments to the manual input <NUM> are also performed in order to reduce or eliminate the possibility of "loss of thrust control", which may be required by certain regulatory bodies.

In this fashion, the autothrottle system <NUM>, for example the autothrottle controller <NUM>, can determine a target position for the manual input <NUM> based on the digital power request produced by the digital interface <NUM>. In some embodiments, the target position can also be based on one or more operating parameters of the engine <NUM>. In embodiments in which the manual input <NUM> is a power lever, the target position can be a particular power lever angle. The autothrottle controller <NUM> is configured for commanding the actuator <NUM> for causing the manual input <NUM> to adopt the target position. The autothrottle controller <NUM> can command the actuator <NUM> using any suitable instructions, protocols, and the like. For example, the autothrottle controller <NUM> can provide the target position to the actuator <NUM>, which interprets the target position as a command to cause the manual input <NUM> to adopt the target position.

In addition, the autothrottle system <NUM> can periodically, or punctually, assess the position of the manual input <NUM> against the operating parameters of the engine <NUM>, and command further changes in the position of the manual input <NUM> in accordance therewith. For example, the autothrottle system <NUM> can detect a change in one or more operating parameters of the engine <NUM> and/or of the propeller <NUM>, and determine a subsequent target position for the manual input <NUM> based on the operating parameters. If the actual position of the manual input <NUM> differs from the subsequent target position, the autothrottle controller <NUM> can command the actuator <NUM> to cause the manual input to adopt the subsequent target position. The autothrottle system <NUM> can repeatedly assess the position of the manual input and adjust it as frequently as appropriate.

In some embodiments, a predetermined tolerance is provided for the target position, and if a mismatch between a current position of the manual input <NUM> and the target position is within the tolerance, the actuator <NUM> is not commanded to cause the manual input <NUM> to adopt the target position. For example, the manual input <NUM> can be set at a position of <NUM>°, and the target position can be <NUM>°. If the tolerance allows a variation of ± <NUM>°, the actuator <NUM> will not be commanded to adjust the position of the manual input <NUM>. Other values for the tolerance, and other methods of assessing the tolerance, are also considered. For example, the tolerance can be based on different engine settings, such as high cruise, mid cruise, low cruise, and the like. In another example, the tolerance is set at approximately <NUM>%, <NUM>%, <NUM>%, or any other suitable percent-based value.

In some embodiments, the tolerance used for the mismatch between the manual input <NUM> and the target position serves to reduce the strain on the actuator <NUM> and/or to minimize distractions for the operator of the aircraft <NUM>. By allowing the mismatch to remain within the predetermined tolerance without adjusting the manual input <NUM>, changes to the position of the manual input <NUM> can be effected only periodically, in response to the mismatch between the current position and the target position exceeding the tolerance.

In some additional embodiments, the autothrottle system <NUM> can alert an operator of the aircraft <NUM> when a mismatch in excess of the predetermined tolerance exists between the current position of the manual input <NUM> and the target input. The alert can be a visual alert, an audible alert, and the like, and can, for example, be displayed via a flight computer of the aircraft <NUM>. The alert can also suggest to the operator to adjust the position of the manual input <NUM> to align with the position of the manual input <NUM> to the target position, for example in embodiments in which the actuator <NUM> is omitted. Alternatively, or in addition, when the mismatch is in excess of the predetermined tolerance, the engine controller <NUM>, or any other suitable device, can issue a fault which causes the autothrottle mode to be disabled. This can result in the manual input mode, based on the manual input <NUM>, to become engaged, and in some cases can additionally cause a maintenance action to be flagged, for example for the operator of the aircraft <NUM>.

With reference to <FIG>, in an alternative embodiment, the engine controller <NUM> and the propeller controller <NUM> can be replaced by a unified controller <NUM>, which is configured for controlling operation of both the engine <NUM> and the propeller <NUM>. The unified controller <NUM> can be controlled based on the manual input <NUM>, for instance when operating in the manual input mode. When the unified controller <NUM> receives the digital power request via the digital interface <NUM> from the autothrottle controller, the unified controller <NUM> is configured for terminating the manual input mode and for engaging the autothrottle mode, thereby controlling the engine <NUM> and the propeller <NUM> based on the digital power request. It should be noted that the unified controller <NUM> can use the same control laws, algorithms, schedules, tables, and the like, in both the autothrottle mode and the manual input mode, and the unified controller <NUM> uses different inputs - from the manual input <NUM> or the digital power request - based on the mode of operation.

In some embodiments, the unified controller <NUM> is configured for receiving the aforementioned digital thrust request from the digital interface <NUM>. The unified controller <NUM> can then determine, based on the digital thrust request, a requisite power level for the engine <NUM> and a requisite rotational speed for the propeller <NUM>. For example, the unified controller <NUM> can produce a digital power request, used within the engine controller <NUM>, and optionally a digital rotational speed request, which can be provided to the propeller controller <NUM>. Still other approaches are considered.

With reference to <FIG>, the techniques described herein can be applied to aircraft <NUM> with multiple powerplants, that is to say, with more than one engine and a commensurate number of propellers. In this embodiment, the aircraft <NUM> is provided with two engines <NUM>, <NUM>, and two propellers <NUM>, <NUM>, though it should be understood that the aircraft can be provided with any suitable number of engines and propellers including three, four, six, eight, or any other suitable number. Each powerplant is provided with suitable controllers: the engine <NUM> is controlled by the engine controller <NUM>, the propeller <NUM> is controlled by the propeller controller <NUM>, the engine <NUM> is controlled by engine controller <NUM>, and the propeller <NUM> is controlled by propeller controller <NUM>. Alternatively, the engine and propeller controllers can be replaced by unified controllers <NUM>, <NUM>, as appropriate.

The autothrottle system <NUM> is thus coupled to controllers for both engines <NUM>, <NUM>, via the digital interface <NUM>. The digital interface <NUM> is configured for providing digital power requests to controllers for both engines <NUM>, <NUM>, in order to cause the engines <NUM>, <NUM>, to operate in the autothrottle mode. In some embodiments, both the engine controllers <NUM>, <NUM> receive the same digital power request. In other embodiments, the engine controllers <NUM>, <NUM> receive different power requests, for example power requests that are scaled based on operating parameters of the engines <NUM>, <NUM>, as provided by the engine controllers <NUM>, <NUM>. The same techniques can be applied with unified controllers <NUM>, <NUM>.

With reference to <FIG>, a system diagram for the aircraft <NUM> is illustrated. The aircraft <NUM> contains an avionics controller <NUM>, a powerplant controller <NUM>, and a thrust controller <NUM>. The avionics controller <NUM> is configured for receiving various control inputs from an operator of the aircraft <NUM>, including a request to engage an autothrottle mode for the aircraft <NUM>. Thus, the avionics controller <NUM> can include the autothrottle input <NUM> as well as the autothrottle system <NUM> of <FIG>. The powerplant controller <NUM> is configured for controlling the operation of a powerplant of the aircraft <NUM>, for example the engine <NUM> and the propeller <NUM> of <FIG>. The thrust controller <NUM> is composed of a power lever angle (PLA) actuator <NUM>, and a PLA rotary variable differential transformer (RVDT) <NUM>, and is configured for providing the powerplant controller <NUM> with instructions on how the powerplant of the aircraft <NUM> should be operated. For example, the thrust controller <NUM> can include the manual input <NUM> and the actuator <NUM> of <FIG>.

In some control modes, for example the manual input mode discussed hereinabove, the operation of the powerplant is largely determined by inputs received at the powerplant controller <NUM> from the thrust controller <NUM>, for example from the PLA RVDT <NUM>. For example, the PLA RVDT <NUM> can translate a power lever angle of a power lever or other embodiment of the manual input <NUM> into a power request for transmission to the powerplant controller <NUM>.

In order to cause the powerplant controller <NUM> to engage the autothrottle mode, the avionics controller <NUM> is configured for providing the digital power request to the powerplant controller <NUM>, bypassing the thrust controller <NUM>. The powerplant controller <NUM> can then terminate the manual input mode, and engage the autothrottle mode based on the digital power request. The powerplant controller <NUM> can then inform the avionics controller <NUM> of a target position for the power lever of the PLA RVDT <NUM>, and, in turn, the avionics controller <NUM> can instruct the PLA actuator <NUM> to cause the power lever to adopt the target position.

With reference to <FIG>, there is illustrated a method <NUM> for controlling autothrottle of an engine, for example the engine <NUM> for the aircraft <NUM>. In some embodiments, the method <NUM> can be implemented via the engine controller <NUM> and, optionally, the propeller controller <NUM>, or by the unified controller <NUM>, and in collaboration with the autothrottle system <NUM>, although other embodiments are considered.

At step <NUM>, an autothrottle readiness condition for the engine <NUM> is evaluated. The autothrottle readiness condition can be based on the particular mode of operation of the engine, one or more operating parameters of the engine, and the like. At decision step <NUM>, if the autothrottle readiness condition is satisfied, the method <NUM> moves to step <NUM>. If the autothrottle readiness condition is not satisfied, the method <NUM> returns to step <NUM>.

At step <NUM>, an autothrottle readiness alert is produced, for example for an operator of an aircraft in which the engine <NUM> is operating, for instance the aircraft <NUM>. The autothrottle readiness alert can be a visual alert, an audible alert, or any other suitable kind of alert.

At step <NUM>, a digital power request is obtained from an autothrottle controller, based on an autothrottle input. The digital power request can be obtained at the engine controller <NUM> from the autothrottle system <NUM>, for example from the digital interface <NUM>, and is based on the autothrottle request obtained via the autothrottle input <NUM>. The digital power request can include any suitable information for controlling the operation of the engine <NUM> as part of an autothrottle mode. In some embodiments, the autothrottle input <NUM> is part of a flight computer of the aircraft <NUM>, which is configured for receiving input from an operator of the aircraft <NUM>.

At step <NUM>, a manual input mode of control for the engine <NUM> is terminated. At step <NUM>, the autothrottle mode for the engine <NUM> is engaged, based on the digital power request. The autothrottle mode can be used to control operation of the engine <NUM> in any suitable fashion. For example, a requisite power output for the engine <NUM>, and optionally a requisite propeller rotation speed for the propeller <NUM>, can be determined, and the engine <NUM> and the propeller <NUM> can be caused to produce power and rotational speed, respectively, commensurate with the requisite amounts.

Optionally, at step <NUM>, a confirmation indication can be produced once the autothrottle mode has been engaged. The confirmation indication can be a visual alert, an audible alert, or any other suitable kind of alert, for example displayed via a flight computer of the aircraft <NUM>.

With additional reference to <FIG>, at step <NUM>, a target position for a manual input, for example the manual input <NUM>, can be determined based on the digital power request, and optionally based on one or more operating parameters of the engine <NUM>. The target position can be indicative of a position which the manual input <NUM> would assume to produce an output from the engine <NUM> which matches the requisite power output requested via the digital power request. At step <NUM>, the target position can be transmitted to an actuator coupled to the manual input <NUM>, for example the actuator <NUM>, to cause the manual input <NUM> to adopt the target position.

In some embodiments, the actuator <NUM> can be repeatedly used to ensure that the manual input <NUM> is substantially continuously, periodically, or punctually adjusted to adopt new target positions, for example in response to changes in the operating conditions of the engine <NUM>. At decision step <NUM>, a determination is made regarding whether a change in operating parameters of the engine <NUM> is detected. If no changes are detected, the method <NUM> can return to step <NUM>. If changes are detected, the method <NUM> proceeds to step <NUM>.

At step <NUM>, a subsequent target position for the manual input <NUM> can be determined, for example based on the operating parameters of the engine <NUM>. At step <NUM>, the subsequent target position can be transmitted to the actuator <NUM> to cause the manual input <NUM> to adopt the subsequent target position. In some embodiments, steps <NUM>, <NUM>, and <NUM> can be repeated substantially continuously, periodically, or punctually throughout a period of time in which the engine <NUM> is operated in the autothrottle mode.

With reference to <FIG>, one or more of the autothrottle system <NUM>, the engine controllers <NUM>, <NUM>, the propeller controllers <NUM>, <NUM>, and/or the unified controllers <NUM>, <NUM>, may be implemented by a computing device <NUM>, comprising a processing unit <NUM> and a memory <NUM> which has stored therein computer-executable instructions <NUM>. The processing unit <NUM> may comprise any suitable devices configured to implement the system <NUM> such that instructions <NUM>, when executed by the computing device <NUM> or other programmable apparatus, may cause the functions/acts/steps of the method <NUM> as described herein to be executed.

In some embodiments, the computing device <NUM> can include one or more full-authority digital engine controls (FADEC), one or more propeller electronic control (PEC) units, and the like. In some embodiments, the engine controllers <NUM>, <NUM> are implemented as dual-channel FADECs. In other embodiments, the engine controllers <NUM>, <NUM> are implemented as two separate single-channel FADECs. Additionally, in some embodiments the propeller controllers <NUM>, <NUM> are implemented as dual-channel PECs, or as two single-channel PECs, or any suitable combination thereof. The unified controllers <NUM>, <NUM> can be implemented as any suitable combination of FADECs, PECs, and/or any other suitable control devices.

The methods and systems for controlling autothrottle of an engine described herein may be implemented in a high level procedural or object oriented programming or scripting language, or a combination thereof, to communicate with or assist in the operation of a computer system, for example the computing device <NUM>. Alternatively, the methods and systems described herein may be implemented in assembly or machine language. The language may be a compiled or interpreted language. Program code for implementing the methods and systems described herein may be stored on a storage media or a device, for example a ROM, a magnetic disk, an optical disc, a flash drive, or any other suitable storage media or device. The program code may be readable by a general or special-purpose programmable computer for configuring and operating the computer when the storage media or device is read by the computer to perform the procedures described herein. Embodiments of the methods and systems described herein may also be considered to be implemented by way of a non-transitory computer-readable storage medium having a computer program stored thereon. The computer program may comprise computer-readable instructions which cause a computer, or in some embodiments the processing unit <NUM> of the computing device <NUM>, to operate in a specific and predefined manner to perform the functions described herein.

Claim 1:
A method for controlling autothrottle of an engine (<NUM>) for a turbopropeller-powered aircraft, the method comprising:
obtaining, from an autothrottle controller (<NUM>), a digital power request, the digital power request based on an autothrottle input (<NUM>) to the autothrottle controller (<NUM>);
in response to obtaining the digital power request, terminating a manual input mode for the engine (<NUM>), the engine (<NUM>), when in the manual input mode, controlled based on a power request obtained from a manual input (<NUM>) associated with the engine (<NUM>);
engaging an autothrottle mode for controlling the engine (<NUM>) based on the digital power request rather than on the power request obtained from the manual input; and
adjusting a position of the manual input (<NUM>) with the autothrottle controller (<NUM>) based on the digital power request for controlling a transition of the engine out of the autothrottle mode.