Methods for automatically initiating stopping of an engine of an aircraft at a desired engine-stop speed are disclosed. An embodiment of the method includes receiving data indicative of a current speed and a current acceleration of the aircraft, the current speed being different from the engine-stop speed of the aircraft. Using the received data, an initiation time at which to initiate stopping of the engine to cause the engine to stop substantially at the engine-stop speed of the aircraft is determined. Stopping of the engine is automatically initiated at the initiation time.

A method for controlling thrust from a turbojet that is fuel flow rate regulated by a high limit value for providing protection against surging of a compressor of the turbojet is provided. The method includes: obtaining a first thrust value corresponding to a first operating point of the compressor on the high limit value, the high limit value taking account of an underestimate of the fuel flow rate; controlling the turbojet to reach the first thrust value; monitoring the turbojet to detect underspeed of the compressor; and where applicable: obtaining a second thrust value corresponding to a second operating point that guarantees a predetermined margin relative to the high limit value so as to obtain protection against underspeed of the turbojet; and controlling the turbojet to reach the second value.

A method for controlling thrust from a turbojet that is fuel flow rate regulated by a high limit value for providing protection against surging of a compressor of the turbojet is provided. The method includes: obtaining a first thrust value corresponding to a first operating point of the compressor on the high limit value, the high limit value taking account of an underestimate of the fuel flow rate; controlling the turbojet to reach the first thrust value; monitoring the turbojet to detect underspeed of the compressor; and where applicable: obtaining a second thrust value corresponding to a second operating point that guarantees a predetermined margin relative to the high limit value so as to obtain protection against underspeed of the turbojet; and controlling the turbojet to reach the second value.

The present disclosure provides systems and methods for controlling thrust produced at takeoff by at least one engine (114, 116) of an aircraft (100). At least one input signal comprising input data indicative of a speed of the aircraft is received (202). The speed of the aircraft is compared to a first pre-determined threshold. Responsive to determining that the speed is below the first threshold, a thrust limit for the at least one engine is determined (204) from the input data and output to the at least one engine a thrust limitation signal for causing the thrust to be limited according to the thrust limit (210).

The present disclosure provides systems and methods for controlling thrust produced at takeoff by at least one engine (114, 116) of an aircraft (100). At least one input signal comprising input data indicative of a speed of the aircraft is received (202). The speed of the aircraft is compared to a first pre-determined threshold. Responsive to determining that the speed is below the first threshold, a thrust limit for the at least one engine is determined (204) from the input data and output to the at least one engine a thrust limitation signal for causing the thrust to be limited according to the thrust limit (210).

According to an aspect, a correction factor for a fuel flow of a fuel system of an engine is determined. A nominal fuel flow is determined based on a metering valve stroke. The correction factor is applied to the nominal fuel flow to produce an estimated fuel flow to control combustion in the engine.

According to an aspect, a correction factor for a fuel flow of a fuel system of an engine is determined. A nominal fuel flow is determined based on a metering valve stroke. The correction factor is applied to the nominal fuel flow to produce an estimated fuel flow to control combustion in the engine.

An auxiliary power unit (APU) control system for an aircraft is disclosed. The APU control system includes an APU, one or more processors, and a memory coupled to the one or more processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the APU control system to receive a one or more ambient signals indicative of an air density value and one or more power signals indicative of a specific amount of power generated by the APU. The APU control system is further caused to determine a variable rotational speed of the APU based on the air density value and instruct the APU to operate at the variable rotational speed. The APU continues to generate the specific amount of power when operating at the variable rotational speed.

An auxiliary power unit (APU) control system for an aircraft is disclosed, and includes an APU drivingly coupled to one or more generators, one or more processors, and a memory coupled to the one or more processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the APU control system to receive one or more ambient signals indicative of an air density value and one or more power signals indicative of a specific amount of power generated by the APU. The system is further caused to determine a first variable rotational speed of the APU based on the air density value. The APU continues to generate the specific amount of power when operating at the first variable rotational speed. After instructing the APU to operate at the first variable rotational speed, the system receives an electrical load signal.

A design method for optimization of a transient control law of the aero-engine is disclosed, and performs the transient schedule optimization for the aero-engine by adopting an SQP algorithm, to realize the design of the transient control law along a constrained boundary condition. The fuel flow rate value is adjusted, other constraints remain unchanged, and the transient control law is designed under different limits. The transient time under each transient control law is calculated by constructing the transient time evaluation function. A lookuptable interpolation table is established by using the calculated transient time and corresponding fuel flow, to realize the fuel flow scheduling under different transient time. The fuel flow obtained by scheduling in the expected time is taken as an acceleration and deceleration control schedule of the closed-loop control of the aero-engine, and the output thereof is taken as the reference instruction of an acceleration process.