A control system and method for engine simulation autorotation training

Abstract

The present application provides a control system and method for engine simulated autorotation training, comprising a helicopter rotor (1), a transmission system (2), a 1# turboshaft engine (3), a 2# turboshaft engine (4), a 1# engine control system (5), a 2# engine control system (6), a 1# engine control switch (7) and a 2# engine control switch (8), wherein: the helicopter rotor (1) is connected to the rotor shaft of the transmission system (2), the power transmission shaft of the transmission system (2) is respectively connected to the 1# turboshaft engine (3) and the 2# turboshaft engine (4), the electrical control circuit of the 1# turboshaft engine (3) is connected to the 1# engine control system (5), the electrical control circuit of the 2# turboshaft engine (4) is connected to the 2# engine control system (6), the 1# engine control system (5) and the 2# engine control system (6) are mutually connected via the electrical control circuit, and the 1# engine control system (5) is connected to the 1# engine control switch (7).

Description

Technical Field

[0001] The invention belongs to the field of helicopter turboshaft engine control, and in particular relates to a control system and method for engine simulated autorotation training. Background Art

[0002] The autorotation landing capability is one of the unique capabilities of helicopters and is also the last means to ensure safety after engine failure. During helicopter training, the ability to simulate autorotation landing training in the air should be possessed to ensure that after all engines fail during a mission flight, the pilot can perform correct and effective operations to enable the helicopter to land safely.

[0003] To achieve helicopter simulated autorotation training, it can be achieved from the following two aspects: one is to quickly reduce the collective pitch to disengage the engine from the helicopter, and the helicopter enters the autorotation state; the other is to put the engine in a state below the slow speed, and the helicopter enters the autorotation state. However, there are cases where twin-engine helicopters cannot put the twin engines in the slow speed state due to engine power problems. The patent of this invention provides a technical approach to disengage the engine from the helicopter and put the helicopter into autorotation by controlling the engine state. Summary of the invention

[0004] The present invention provides a control system and method for engine simulated autorotation training, which can meet the use requirements of helicopter control in a twin-engine helicopter training autorotation state.

[0005] In a first aspect, the present application provides a control system for engine simulated autorotation training, including a helicopter rotor 1, a transmission system 2, a 1# turboshaft engine 3, a 2# turboshaft engine 4, a 1# engine control system 5, a 2# engine control system 6, a 1# engine control switch 7, and a 2# engine control switch 8, wherein:

[0006] The helicopter rotor 1 is connected to the rotor shaft of the transmission system 2, the power transmission shaft of the transmission system 2 is respectively connected to the 1# turboshaft engine 3 and the 2# turboshaft engine 4, the electrical control circuit of the 1# turboshaft engine 3 is connected to the 1# engine control system 5, the electrical control circuit of the 2# turboshaft engine 4 is connected to the 2# engine control system 6, the 1# engine control system 5 and the 2# engine control system 6 are connected to each other through the electrical control circuit, the 1# engine control system 5 is connected to the 1# engine control switch 7, and the 2# engine control system 6 is connected to the 2# engine control switch 8.

[0007] Specifically, the 1# engine control switch 7 and the 2# engine control switch 8 are used to output the simulated autorotation training control instruction signal;

[0008] The 1# engine control system 5 and the 2# engine control system 6 are used to receive control instructions, change the Np closed-loop control to the Ngtarget closed-loop control, and the control system adjusts the engine fuel flow and acts on the engine to reduce the engine gas turbine speed Ng to the target Ngtarget. At this time, the engine output power drops significantly, the power transmission shaft speed Np is lower than 100%, and it is disconnected from the transmission system.

[0009] Specifically, the transmission system 2 is used to connect the power output shafts of the two engines and the helicopter rotor, and transmit the power turbine torque to the helicopter rotor. The mechanical connection used makes the engine power turbine speed and the helicopter rotor speed consistent at a fixed transmission ratio.

[0010] In a second aspect, the present application provides a control method for engine simulated autorotation training, characterized in that the method comprises:

[0011] Step 1: If the 1# engine control switch 7 or the 2# engine control switch 8 receives a switch signal indicating that the simulated autorotation training function is turned on, and the simulated autorotation training entry condition is met, the simulated autorotation training function is turned on;

[0012] Step 2: The 1# engine control switch 7 or the 2# engine control switch 8 sends the switch signal to the corresponding 1# engine control system 5 or the 2# engine control system 6;

[0013] Step 3: After receiving the switch signal, the 1# engine control system 5 or the 2# engine control system 6 controls the corresponding 1# turboshaft engine 3 or 2# turboshaft engine 4 to change from Np closed-loop control to gas turbine speed Ngtarget closed-loop control;

[0014] Step 4: The fuel of the 1# turboshaft engine 3 or the 2# turboshaft engine 4 is reduced, the Np speed decreases, the transmission system of the 1# turboshaft engine 3 or the 2# turboshaft engine 4 is disengaged, and the helicopter enters the autorotation state;

[0015] Step 5: When the simulated autorotation training exit condition is met, the simulated autorotation training function is disconnected;

[0016] Step 6: 1# engine control system 5 or 2# engine control system 6 restores Np closed-loop control, 1# turboshaft engine 3 or 2# turboshaft engine 4 is refueled, engages with the transmission system, and resumes normal working state.

[0017] Specifically, the conditions for entering the simulated rotation training are:

[0018] No. 1 engine control system 5 and No. 2 engine control system 6 are both fault-free;

[0019] And both the 1# engine control switch 7 and the 2# engine control switch 8 are in the flight state control position.

[0020] Specifically, the simulated rotation training exit condition is:

[0021] If any of the following conditions are met, the simulated autorotation landing training control will be exited:

[0022] If either the 1# engine control switch 7 or the 2# engine control switch 8 is not in the flight state control position, the control systems of both engines will exit the Ngtarget closed-loop control and control will be performed according to the engine state of the position of the engine state control switch;

[0023] If the 1# engine control system 5 or the 2# engine control system 6 is not in the simulated autorotation training function on position, the station will exit the Ngtarget closed-loop control and control the engine state according to the position of the engine state control switch;

[0024] If there is a control system failure in 1# turboshaft engine 3 or 2# turboshaft engine 4, both engines will exit Ngtarget closed-loop control and be controlled according to the engine state of the position of the engine state control switch.

[0025] Specifically, Ngtarget closed-loop control is a turboshaft engine that maintains a target speed by controlling the fuel flow to keep the gas turbine speed constant.

[0026] Specifically, Np closed-loop control is that the turboshaft engine maintains the target speed constant by controlling the fuel flow to keep the power turbine speed.

[0027] In summary, the present invention provides a control method for engine simulated autorotation training, which realizes a technical solution for helicopter autorotation training without shutting down the engine by controlling the state of the helicopter turboshaft engine. The technology can be applied to conventional twin-engine helicopters and turboshaft engines with numerical control systems. It can ensure that the engine is disengaged from the helicopter transmission system at an engine slow speed. Compared with the traditional method of quickly releasing the collective pitch to make the helicopter rotor speed higher than the engine output shaft speed, it can provide the pilot with a wider range of rotor speed changes to carry out simulated autorotation training. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the structure of a control system for engine simulated autorotation training provided in this application. DETAILED DESCRIPTION

[0029] Embodiment 1

[0030] like Figure 1As shown, the present application provides a control system for engine simulated autorotation training, including a helicopter rotor 1, a transmission system 2, a 1# turboshaft engine 3, a 2# turboshaft engine 4, a 1# engine control system 5, a 2# engine control system 6, a 1# engine control switch 7 and a 2# engine control switch 8, wherein:

[0031] The helicopter rotor 1 is connected to the rotor shaft of the transmission system 2, the power transmission shaft of the transmission system 2 is respectively connected to the 1# turboshaft engine 3 and the 2# turboshaft engine 4, the electrical control circuit of the 1# turboshaft engine 3 is connected to the 1# engine control system 5, the electrical control circuit of the 2# turboshaft engine 4 is connected to the 2# engine control system 6, the 1# engine control system 5 and the 2# engine control system 6 are connected to each other through the electrical control circuit, the 1# engine control system 5 is connected to the 1# engine control switch 7, and the 2# engine control system 6 is connected to the 2# engine control switch 8.

[0032] Specifically, the 1# engine control switch 7 and the 2# engine control switch 8 are used to output the simulated autorotation training control instruction signal;

[0033] The 1# engine control system 5 and the 2# engine control system 6 are used to receive control instructions, change the Np closed-loop control to the Ngtarget closed-loop control, and the control system adjusts the engine fuel flow and acts on the engine to reduce the engine gas turbine speed Ng to the target Ngtarget. At this time, the engine output power drops significantly, the power transmission shaft speed Np is lower than 100%, and it is disconnected from the transmission system.

[0034] The transmission system 2 is used to connect the power output shafts of the two engines and the helicopter rotor, and transmit the power turbine torque to the helicopter rotor. The mechanical connection used makes the engine power turbine speed and the helicopter rotor speed consistent at a fixed transmission ratio.

[0035] Embodiment 2

[0036] The present invention provides a control method for engine simulated autorotation training, which is applied to a helicopter variable rotor speed control system, and comprises:

[0037] Step 1: If the 1# engine control switch 7 or the 2# engine control switch 8 receives a switch signal indicating that the simulated autorotation training function is turned on, and the simulated autorotation training entry condition is met, the simulated autorotation training function is turned on;

[0038] Specifically, the conditions for entering the simulated autorotation training are: both the 1# engine control system 5 and the 2# engine control system 6 are fault-free; and both the 1# engine control switch 7 and the 2# engine control switch 8 are in the flight state control position.

[0039] Step 2: The 1# engine control switch 7 or the 2# engine control switch 8 sends the switch signal to the corresponding 1# engine control system 5 or the 2# engine control system 6;

[0040] Step 3: After receiving the switch signal, the 1# engine control system 5 or the 2# engine control system 6 controls the corresponding 1# turboshaft engine 3 or 2# turboshaft engine 4 to change from Np closed-loop control to gas turbine speed Ngtarget closed-loop control;

[0041] It should be noted that Np closed-loop control is a turboshaft engine that controls the fuel flow rate to keep the power turbine speed constant to maintain the target speed. Ngtarget closed-loop control is a turboshaft engine that controls the fuel flow rate to keep the gas turbine speed constant to maintain the target speed.

[0042] Step 4: The fuel of the 1# turboshaft engine 3 or the 2# turboshaft engine 4 is reduced, the Np speed decreases, the transmission system of the 1# turboshaft engine 3 or the 2# turboshaft engine 4 is disengaged, and the helicopter enters the autorotation state;

[0043] Step 5: When the simulated autorotation training exit condition is met, the simulated autorotation training function is disconnected;

[0044] Specifically, the simulated autorotation training exit condition is that if any of the following conditions is met, the simulated autorotation landing training control is exited:

[0045] If either the 1# engine control switch 7 or the 2# engine control switch 8 is not in the flight state control position, the control systems of both engines will exit the Ngtarget closed-loop control and control will be performed according to the engine state of the position of the engine state control switch;

[0046] If the 1# engine control system 5 or the 2# engine control system 6 is not in the simulated autorotation training function on position, the station will exit the Ngtarget closed-loop control and control the engine state according to the position of the engine state control switch;

[0047] If there is a control system failure in 1# turboshaft engine 3 or 2# turboshaft engine 4, both engines will exit Ngtarget closed-loop control and be controlled according to the engine state of the position of the engine state control switch.

[0048] Step 6: 1# engine control system 5 or 2# engine control system 6 restores Np closed-loop control, 1# turboshaft engine 3 or 2# turboshaft engine 4 is refueled, engages with the transmission system, and resumes normal working state.

[0049] It should be noted that a notable feature of the present invention is that when the helicopter is in flight, the pilot can choose to perform simulated autorotation training, and can control the engine to lower and disconnect from the helicopter transmission system by operating the control switch, and the helicopter will enter the autorotation state.

[0050] In summary, the present invention provides a control method for engine simulated autorotation training. Compared with the prior art, the present invention has the following advantages and innovations:

[0051] a) The solution of the present invention provides a method for making a helicopter enter an autorotation state by controlling a turboshaft engine to enter a low state and disengage from a transmission system, wherein the engine can maintain low-state operation and can quickly return to a normal state when the pilot needs to exit the autorotation state;

[0052] b) The present invention enables a helicopter equipped with a high-power engine to be capable of carrying out autorotation training, ensuring that the engine is disconnected from the rotor system without shutting down the engine, so that the pilot can carry out autorotation training in a wider rotor speed range;

[0053] c) The present invention proposes to set entry and exit conditions for the simulated autorotation training function, which can effectively ensure the safety of the helicopter when using this function.

[0054] The present invention provides a control method for engine simulated autorotation training, which is a technical solution for realizing helicopter autorotation training without shutting down the engine by controlling the state of a helicopter turboshaft engine. The technology can be applied to a conventional twin-engine helicopter and a turboshaft engine with a numerical control system, and can ensure that the engine is disengaged from the helicopter transmission system at an engine slow speed. Compared with the conventional method of rapidly releasing the collective pitch to make the helicopter rotor speed higher than the engine output shaft speed, the technology can provide the pilot with the ability to carry out simulated autorotation training within a wider range of rotor speed variations.

Claims

1. A control system for engine simulation autorotation training, characterized in that: The invention comprises a helicopter rotor (1), a transmission system (2), a first turboshaft engine (3), a second turboshaft engine (4), a first engine control system (5), a second engine control system (6), a first engine control switch (7) and a second engine control switch (8), wherein: The helicopter rotor (1) is connected to the rotor shaft of the transmission system (2); the power transmission shaft of the transmission system (2) is respectively connected to the first turboshaft engine (3) and the second turboshaft engine (4); the electrical control circuit of the first turboshaft engine (3) is connected to the first engine control system (5); the electrical control circuit of the second turboshaft engine (4) is connected to the second engine control system (6); the first engine control system (5) and the second engine control system (6) are connected to each other via the electrical control circuit; the first engine control system (5) is connected to the first engine control switch (7); and the second engine control system (6) is connected to the second engine control switch (8); The first engine control switch (7) and the second engine control switch (8) are used to output a simulated autorotation training control instruction signal; The first engine control system (5) and the second engine control system (6) are used to receive control instructions, change the Np closed-loop control to the Ngtarget closed-loop control, and the control system adjusts the engine fuel flow and acts on the engine, so that the engine gas turbine speed Ng drops to the target Ngtarget, at which time the engine output power drops significantly, the power transmission shaft speed Np is lower than 100%, and the engine is disconnected from the transmission system; The transmission system (2) is used to connect the power output shafts of the two engines and the helicopter rotor, and transmit the power turbine torque to the helicopter rotor. The mechanical connection used allows the engine power turbine speed and the helicopter rotor speed to remain consistent at a fixed transmission ratio.

2. A control method for engine simulated autorotation training, characterized in that: Methods include: Step 1: If the first engine control switch (7) or the second engine control switch (8) receives a switch signal indicating that the simulated autorotation training function is turned on, and if the simulated autorotation training entry condition is met, the simulated autorotation training function is turned on; Step 2: The first engine control switch (7) or the second engine control switch (8) sends a switch signal to the corresponding first engine control system (5) or the second engine control system (6); Step 3: After receiving the switch signal, the first engine control system (5) or the second engine control system (6) controls the corresponding first turboshaft engine (3) or the second turboshaft engine (4) to change from Np closed-loop control to gas turbine speed Ngtarget closed-loop control; Step 4: The fuel of the first turboshaft engine (3) or the second turboshaft engine (4) is reduced, the Np speed decreases, the transmission system of the first turboshaft engine (3) or the second turboshaft engine (4) is disengaged, and the helicopter enters an autorotation state; Step 5: When the simulated autorotation training exit condition is met, the simulated autorotation training function is disconnected; Step 6: The first engine control system (5) or the second engine control system (6) restores the Np closed-loop control, and the first turboshaft engine (3) or the second turboshaft engine (4) is refueled, meshed with the transmission system, and restored to a normal working state; The entry conditions for the simulated rotation training are: The first engine control system (5) and the second engine control system (6) are both free of faults; The first engine control switch (7) and the second engine control switch (8) are both in the flight state control position; The simulated rotation training exit condition is: If any of the following conditions are met, the simulated autorotation landing training control will be exited: If either the first engine control switch (7) or the second engine control switch (8) is not in the flight state control position, both engine control systems exit the Ngtarget closed-loop control and control is performed according to the engine state of the position of the engine state control switch; If the first engine control system (5) or the second engine control system (6) is not in the simulated autorotation training function on position, the engine will exit the Ngtarget closed loop control and control will be performed according to the engine state of the position of the engine state control switch; If a control system failure occurs in the first turboshaft engine (3) or the second turboshaft engine (4), both engines exit the Ngtarget closed-loop control and are controlled according to the engine state of the position of the engine state control switch; Ngtarget closed-loop control is a turboshaft engine that controls the fuel flow rate to keep the gas turbine speed constant at the target speed; Np closed-loop control is a turboshaft engine that controls the fuel flow to keep the power turbine speed constant to maintain the target speed.

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