Adaptive Timing Control Method and System for Propellant Starting in Turbine Engines

Abstract

This invention discloses an adaptive timing control method and system for propellant starting in a turbine engine. The method includes: detecting the current ambient temperature to obtain the corresponding initial propellant temperature; acquiring a pressure reference curve and an acceleration reference curve corresponding to the initial propellant temperature, and constructing an acceleration prediction model based on the pressure reference curve and the acceleration reference curve; predicting the time required for the engine rotor speed to reach the ignition speed based on the acceleration reference curve, and generating corresponding reference injection time and reference ignition time; and real-time correcting the reference injection time and the reference ignition time based on the difference between the measured acceleration and the predicted acceleration of the engine rotor, generating and updating the target injection time and the target ignition time until the target injection time is reached at the current time. This invention provides an adaptive timing control method with high control accuracy and fast response to solve the robust matching problem of propellant starting timing.

Description

Technical Field

[0001] This invention relates to the field of turbine engines, and more particularly to an adaptive timing control method and system for propellant starting in a turbine engine. Background Technology

[0002] The starting procedure for a turbocharged engine is as follows:

[0003] Preparation and triggering phase: The system is powered on and the controller performs a self-test; based on the start command given by the aircraft, the controller sends a trigger current to the propellant starter;

[0004] Starter-driven rotation stage: Ignition of the main charge generates high-pressure gas, which drives the starter turbine, causing the engine rotor to rotate rapidly;

[0005] Fuel injection and ignition: When the rotor speed reaches the optimal ignition speed, the controller issues a fuel injection command; fuel is injected into the combustion chamber to form a fuel mist; after a millisecond delay, the controller triggers the igniter to ignite the flame;

[0006] Flame establishment and transition: A high-energy flame ignites the fuel-air mixture, and the initial flame core is established in the combustion chamber; the exhaust temperature begins to rise sharply; during this process, the propellant power decreases, and the engine begins to accelerate by relying on the gas energy generated by its own combustion.

[0007] Autonomous acceleration to closed loop: the propellant burns out and the starter disengages; the engine controller increases fuel according to the acceleration fuel supply plan; the rotor relies entirely on the turbine power to continuously accelerate until the preset speed is reached.

[0008] Traditional turbine engines often use a fixed fuel injection ignition sequence for their propellant starting method. However, the pressure-time curve of propellant combustion fluctuates, and a fixed sequence can easily lead to starting failure or exceeding limits.

[0009] Based on the above problems, existing technologies mostly adopt the approach of increasing design margin or pure feedback control. Increasing design margin sacrifices efficiency and lifespan, while pure feedback control suffers from response lag and is difficult to cope with rapidly changing propellant dynamic processes. Summary of the Invention

[0010] This invention addresses the shortcomings of existing technologies that struggle to adaptively adjust fuel injection and ignition timing for rapidly changing propellant dynamic processes by providing a method and system for adaptive timing control of propellant starting in turbine engines.

[0011] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0012] In a first aspect, the present invention provides an adaptive timing control method for propellant starting in a turbine engine, comprising the following steps:

[0013] Detect the current ambient temperature to obtain the corresponding initial loading temperature;

[0014] Obtain the pressure reference curve and acceleration reference curve corresponding to the initial temperature of the charge, and construct an acceleration prediction model based on the pressure reference curve and the acceleration reference curve. The acceleration prediction model is used to characterize the mapping relationship between pressure and acceleration. Wherein, pressure refers to the pressure of the propellant gas and acceleration refers to the acceleration of the engine rotor.

[0015] Based on the acceleration reference curve, the time required for the engine rotor speed to reach the ignition speed is predicted, and the corresponding reference injection time and reference ignition time are generated.

[0016] Based on the difference between the measured acceleration and the predicted acceleration of the engine rotor, the reference injection time and the reference ignition time are corrected in real time to generate and update the target injection time and the target ignition time until the target injection time is reached at the current time.

[0017] The method for obtaining the predicted acceleration is as follows: based on the pressure reference curve, the predicted pressure corresponding to the current moment is obtained, and the acceleration prediction model outputs the corresponding predicted acceleration according to the predicted pressure.

[0018] As one possible implementation method:

[0019] The engine rotor speed is detected in real time, and the corresponding acceleration is calculated to obtain the corresponding measured acceleration;

[0020] The predicted pressure at the current moment is predicted based on the pressure reference curve.

[0021] Based on the predicted pressure and the drag torque corresponding to the current rotational speed, the acceleration at the current moment is predicted using the acceleration prediction model to obtain the corresponding predicted acceleration;

[0022] The difference between the measured acceleration and the predicted acceleration at the current time is input into the PI controller, and the PI controller outputs the corresponding first time correction value.

[0023] Update the target injection time based on the first time correction value and the reference injection time;

[0024] The target ignition time is updated based on the first time correction value and the reference ignition time.

[0025] As one possible implementation method, the corresponding adaptive timing control method for propellant starting in a turbine engine includes:

[0026] The second time correction value is obtained by weighting the first time correction value based on preset weighting coefficients:

[0027] The target injection time is generated and updated based on the superposition of the first time correction value and the reference injection time.

[0028] The second time correction value and the reference ignition time are superimposed to generate and update the target ignition time.

[0029] As one possible implementation method:

[0030] A library of performance curves corresponding to different types of gunpowder is provided. The library includes several sets of performance curves, and each set of performance curves corresponds to a different first reference temperature.

[0031] Each set of performance curves includes a pressure-time curve and an acceleration-time curve at the corresponding first reference temperature.

[0032] As one possible implementation, when the target gunpowder type does not match the preset performance curve library:

[0033] Based on a pre-defined performance curve library, the pressure reference curve and acceleration reference curve corresponding to the initial loading temperature are obtained, and an acceleration prediction model is constructed based on the pressure reference curve and the acceleration reference curve.

[0034] Obtain the gas pressure characteristics corresponding to the target gunpowder type;

[0035] The pressure reference curve is corrected based on the gas pressure characteristics, and the acceleration reference curve is reconstructed based on the acceleration prediction model according to the corrected pressure reference curve.

[0036] Based on the reconstructed acceleration reference curve, the time required for the engine rotor speed to reach the ignition speed is predicted, and the corresponding reference injection time and reference ignition time are generated.

[0037] The predicted pressure at the current moment is predicted based on the corrected pressure baseline curve.

[0038] As one possible implementation method, the steps for obtaining the pressure reference curve and acceleration reference curve corresponding to the initial charge temperature based on a preset performance curve library are as follows:

[0039] The performance curve with the first reference temperature as the initial loading temperature is obtained from the preset performance curve library to obtain the corresponding pressure reference curve and acceleration reference curve.

[0040] Alternatively, two sets of performance curves adjacent to the first reference temperature and the initial charge temperature can be obtained from a preset performance curve library. The pressure-time curves in the performance curves can be interpolated to obtain a pressure reference curve corresponding to the initial charge temperature. The acceleration-time curves in the performance curves can be interpolated to obtain a corresponding acceleration reference curve.

[0041] As one possible implementation method:

[0042] The gas pressure characteristics include several gas pressure curves or maximum gas pressure corresponding to a second reference temperature;

[0043] When the gas pressure characteristic is the gas pressure curve, the gas pressure curve corresponding to the initial charge temperature is used as the corrected pressure reference curve.

[0044] When the gas pressure characteristic is the maximum gas pressure, the corresponding pressure reference curve is corrected based on the maximum gas pressure corresponding to the initial charging temperature.

[0045] As one possible implementation method:

[0046] The initial injection time and initial ignition time are pre-configured, and the time interval between the initial injection time and the initial ignition time is used as the initial ignition interval.

[0047] Several deviation levels and corresponding interval adjustment parameters are pre-configured. The deviation levels are used to indicate the direction and degree of deviation of the reference injection time relative to the initial injection time.

[0048] When the corresponding reference injection time is obtained based on the corresponding acceleration reference curve:

[0049] Calculate the difference between the reference injection time and the initial injection time to determine the deviation level corresponding to the reference injection time; correct the initial ignition interval based on the interval adjustment parameter corresponding to the deviation level to obtain the target ignition interval;

[0050] A corresponding reference ignition time is generated based on the reference injection time and the target ignition interval.

[0051] Secondly, the present invention provides an adaptive timing control system for propellant starting in a turbine engine, comprising:

[0052] A temperature sensor detects the current ambient temperature to obtain the corresponding initial loading temperature;

[0053] The feedforward module is used to acquire the pressure reference curve and acceleration reference curve corresponding to the initial temperature of the propellant charge, and to construct an acceleration prediction model based on the pressure reference curve and the acceleration reference curve. The acceleration prediction model is used to characterize the mapping relationship between pressure and acceleration. Here, pressure refers to the pressure of the propellant gas and acceleration refers to the acceleration of the engine rotor. It is also used to predict the time required for the engine rotor speed to reach the ignition speed based on the acceleration reference curve, and to generate the corresponding reference injection time and reference ignition time.

[0054] The feedback module is used to correct the reference injection time and the reference ignition time in real time based on the difference between the measured acceleration and the predicted acceleration of the engine rotor, and to generate and update the target injection time and the target ignition time until the current time reaches the target injection time; wherein, the predicted acceleration is the predicted acceleration obtained by the acceleration prediction model based on the predicted pressure corresponding to the current time obtained from the pressure reference curve.

[0055] As one possible implementation, the feedback module includes:

[0056] A speed sensor is used to detect the rotational speed of the engine rotor in real time;

[0057] The first calculation unit is used to calculate the corresponding acceleration based on the rotational speed to obtain the corresponding measured acceleration;

[0058] The pressure prediction unit is used to predict the pressure at the current moment based on the pressure reference curve.

[0059] An acceleration prediction unit is used to predict the acceleration at the current moment based on the acceleration prediction model, according to the predicted pressure and the drag torque corresponding to the current rotation speed, and to obtain the corresponding predicted acceleration.

[0060] The closed-loop feedback unit is used to input the difference between the measured acceleration and the predicted acceleration at the current time into the PI controller, and the PI controller outputs the corresponding first time correction value.

[0061] The correction unit is configured to update the target injection time based on the first time correction value and the reference injection time; and to update the target ignition time based on the first time correction value and the reference ignition time.

[0062] This invention, by adopting the above technical solutions, has significant technical effects:

[0063] This invention, through the design of reference injection timing and reference ignition timing, can compensate for predictable disturbances such as temperature effects in advance, significantly improve the system response speed, and achieve a substantial leap in control accuracy compared to pure feedback schemes.

[0064] Before fuel injection, the reference fuel injection timing and reference ignition timing are adjusted based on the difference between the measured acceleration and the predicted acceleration. This can significantly broaden the engine's tolerance range to fluctuations in propellant performance, effectively improve its first-shot success rate and starting safety under harsh conditions such as extreme low temperatures, and comprehensively enhance the system's operational reliability. Attached Figure Description

[0065] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0066] Figure 1 This is a flowchart illustrating an adaptive timing control method for propellant starting in a turbine engine according to the present invention.

[0067] Figure 2 A schematic diagram of the propellant pressure versus time during a ground static test;

[0068] Figure 3 This is a schematic diagram of a model for predicting engine rotor acceleration over time. Detailed Implementation

[0069] The present invention will be further described in detail below with reference to the embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0070] This application provides an adaptive timing control method for propellant starting in a turbine engine, such as... Figure 1 As shown, it includes the following steps:

[0071] S100: Detect the current ambient temperature and obtain the corresponding initial loading temperature;

[0072] S200. Obtain the pressure reference curve and acceleration reference curve corresponding to the initial temperature of the charge, and construct an acceleration prediction model based on the pressure reference curve and the acceleration reference curve.

[0073] The pressure reference curve is a curve showing how pressure changes over time;

[0074] The acceleration reference curve is a curve showing how acceleration changes over time;

[0075] The acceleration prediction model is used to characterize the mapping relationship between pressure and acceleration;

[0076] The pressure mentioned above refers to the pressure of the propellant gas, and the acceleration refers to the acceleration of the engine rotor.

[0077] The specific steps for obtaining the pressure reference curve and acceleration reference curve corresponding to the initial temperature of the propellant charge are as follows:

[0078] S210, Preset performance curve library corresponding to gunpowder type;

[0079] The performance curve library includes several sets of performance curves, and the first reference temperature corresponding to each set of performance curves is different.

[0080] Each set of performance curves includes a pressure-time curve and an acceleration-time curve at the corresponding first reference temperature.

[0081] S211. Based on the target turbine engine's propellant starter and corresponding nozzle, and the specified propellant type, obtain the pressure-time curves at each first reference temperature through experiments.

[0082] In this embodiment, a ground static test was conducted in advance on the gunpowder starter and corresponding nozzle corresponding to the target turbine engine, and on the change law of gunpowder gas pressure for the specified gunpowder type.

[0083] In this ground static experiment, multiple rounds of experiments were conducted on different batches of gunpowder for a specified type of gunpowder using controlled variables. The obtained static experimental data were used to fit and obtain the pressure-time curve at the corresponding first reference temperature to indicate the gunpowder gas pressure P. m With time t, first reference temperature T init and the changing pattern of gunpowder characteristic Q, i.e., P m (t)=f(Q,T init The curves showing the change in propellant gas pressure over time at different initial charge temperatures are shown below. Figure 2 As shown.

[0084] This embodiment also pre-conducts a ground static test on the acceleration variation law for the target turbine engine and the corresponding gunpowder starter, and for the specified gunpowder type (consistent with the gunpowder type used in the above experiment);

[0085] Reference Figure 3 In this ground static experiment, the acceleration at the corresponding time point is obtained by integrating the speed signal from the engine speed sensor, thus obtaining the acceleration-time curve at the corresponding first reference temperature. This curve is used to indicate the variation of the engine rotor acceleration over time, i.e., a m (t).

[0086] As an example, when the target gunpowder type matches a pre-defined library of performance curves:

[0087] S221. Obtain the performance curve with the first reference temperature as the initial loading temperature from the preset performance curve library, so as to obtain the corresponding pressure reference curve and acceleration reference curve.

[0088] That is, a first reference temperature that matches the initial temperature of the charge is found in the preset performance curve library, and the pressure-time curve corresponding to the first reference temperature is used as the corresponding pressure reference curve, and the acceleration-time curve is used as the corresponding acceleration reference curve.

[0089] S222. Obtain two sets of performance curves adjacent to the first reference temperature and the initial loading temperature from the preset performance curve library. Interpolate the pressure-time curve in the performance curve to obtain a pressure reference curve corresponding to the initial loading temperature. Perform difference calculation on the acceleration-time curve in the performance curve to obtain a corresponding acceleration reference curve.

[0090] That is, if a first reference temperature that matches the initial loading temperature is not found in the preset performance curve library, then the first reference temperature that is adjacent to the initial loading temperature will be searched to obtain the corresponding two sets of performance curves.

[0091] If the initial loading temperature is 26℃ and the performance curve library does not have a preset performance curve at this temperature, then obtain the first reference temperature that is adjacent to it and retrieve its performance curve, such as the performance curves at 25℃ and 30℃.

[0092] Interpolation is performed based on the pressure-time curves at 25℃ and 30℃ to obtain the pressure-time curve corresponding to 26℃, that is, to obtain the corresponding pressure reference curve.

[0093] Interpolation is performed on the acceleration-time curves at 25℃ and 30℃ to obtain the acceleration-time curve corresponding to 26℃, which is the corresponding acceleration reference curve.

[0094] S223. Construct an acceleration prediction model based on the pressure reference curve and the acceleration reference curve;

[0095] Engine acceleration originates from the impulse of gunpowder combustion and injection. That is, when the gunpowder nozzle is fixed, the thrust of gunpowder on the engine rotor is proportional to its gas pressure.

[0096] Given the pressure baseline curve (pressure-time) and the acceleration baseline curve (acceleration-time), curve fitting can be performed based on time to obtain the corresponding acceleration-pressure curve, that is, to obtain the acceleration prediction model.

[0097] As another example, when the target gunpowder type does not match the preset performance curve library:

[0098] The corresponding pressure reference curve and acceleration reference curve are corrected based on the gas pressure characteristics corresponding to the target gunpowder type;

[0099] Specifically:

[0100] S231. Based on a preset performance curve library, obtain the pressure reference curve and acceleration reference curve corresponding to the initial loading temperature, and construct an acceleration prediction model based on the pressure reference curve and the acceleration reference curve.

[0101] That is, according to the above steps S221 or S222, the pressure reference curve and acceleration reference curve corresponding to the initial loading temperature are obtained based on the preset performance curve library.

[0102] S232. Obtain the gas pressure characteristics corresponding to the target gunpowder type;

[0103] The gas pressure characteristics described in this embodiment include several gas pressure curves or maximum gas pressure corresponding to a second reference temperature;

[0104] S233. Correct the pressure reference curve based on the gas pressure characteristics;

[0105] The gas pressure characteristics are provided by the corresponding gunpowder manufacturer. In practical applications, the pressure reference curve is corrected based on the type of gas pressure characteristics provided by the manufacturer, specifically as follows:

[0106] When the gas pressure characteristic is a gas pressure curve, the gas pressure curve corresponding to the initial charging temperature is used as the corrected pressure reference curve. That is, according to the above steps S221 or S222, the gas pressure curve corresponding to the initial charging temperature is obtained, and the gas pressure curve is used to replace the pressure reference curve obtained earlier based on the performance curve library to obtain the corrected pressure reference curve.

[0107] When the gas pressure characteristic is the maximum gas pressure, the corresponding pressure reference curve is corrected based on the maximum gas pressure corresponding to the initial charging temperature. That is, based on the gas pressure characteristic, the maximum gas pressure corresponding to the initial charging temperature is taken as the first maximum gas pressure, and the maximum gas pressure corresponding to the pressure reference curve is taken as the second maximum gas pressure. Based on the ratio of the second maximum gas pressure to the first maximum gas pressure, the gas pressure in the pressure reference curve is scaled to obtain the corrected pressure reference curve, wherein the maximum gas pressure of the corrected pressure reference curve is consistent with the first maximum gas pressure.

[0108] S234. Based on the corrected pressure reference curve, and the acceleration prediction model, reconstruct the acceleration reference curve.

[0109] That is, each point in the corrected pressure reference curve obtained in step S233 is input into the acceleration prediction model constructed in step S231, and a new acceleration reference curve is generated based on the prediction results output by the acceleration prediction model, namely the reconstructed acceleration reference curve.

[0110] S300. Based on the acceleration reference curve, predict the time required for the engine rotor speed to reach the ignition speed, and generate the corresponding reference injection time and reference ignition time.

[0111] The acceleration reference curve here is the acceleration reference curve obtained in step S221, step S222, or step S234;

[0112] Ignition speed is the preset value;

[0113] Given the acceleration reference curve and the ignition speed, those skilled in the art can easily calculate the time required for the engine rotor speed to increase from 0 to the ignition speed, and obtain the waiting time.

[0114] The starting time of the gunpowder starter is the initial moment, that is, the moment when the engine starting mass is sent out;

[0115] The moment when the rotational speed reaches the ignition speed is the optimal moment for the gunpowder to start up under the current environment. In this embodiment, it is used as the reference injection time.

[0116] The ignition timing is usually a very short time after the fuel injection timing. In the existing technology, a fixed interval is generally used as the ignition interval.

[0117] The fixed interval between fuel injection and ignition makes it impossible to adaptively adjust to external environments, which can significantly affect ignition success rate under extreme temperatures. To address this issue, this embodiment adaptively adjusts the ignition interval based on the direction and degree of deviation between the obtained reference fuel injection time and the initial fuel injection time, thereby determining the corresponding reference ignition time. The specific steps are as follows:

[0118] S310, Pre-configure the initial injection time and the initial ignition time, and use the time interval between the initial injection time and the initial ignition time as the initial ignition interval;

[0119] Those skilled in the art can select a reference temperature according to the actual situation, and determine the initial injection time and initial ignition time based on the performance curve corresponding to the reference temperature;

[0120] In this embodiment, +15℃ is selected as the reference temperature;

[0121] The purpose of preset initial injection timing and initial ignition timing is to prevent unexpected situations such as sensor failure.

[0122] S320. Several deviation levels and corresponding interval adjustment parameters are pre-configured. The deviation levels are used to indicate the direction and degree of deviation of the reference injection time relative to the initial injection time.

[0123] Those skilled in the art can pre-calculate the injection time corresponding to the first reference temperature in the performance curve library, and calculate the time difference between the obtained injection time of each nozzle and the initial injection time. Then, based on actual needs, several deviation levels can be configured according to the obtained time difference to indicate different degrees of deviation (including direction).

[0124] Those skilled in the art can configure the interval adjustment parameters for each deviation level according to actual needs. These interval adjustment parameters are used to correct the initial ignition interval.

[0125] S330. Based on the difference between the obtained reference injection time and the initial injection time, determine the corresponding deviation level, and correct the initial ignition interval based on the interval adjustment parameter of the deviation level to obtain the corresponding reference ignition time.

[0126] That is, when the corresponding reference injection time is obtained based on the corresponding acceleration reference curve:

[0127] Calculate the difference between the reference injection time and the initial injection time to determine the deviation level corresponding to the reference injection time; correct the initial ignition interval based on the interval adjustment parameter corresponding to the deviation level to obtain the target ignition interval;

[0128] A corresponding reference ignition time is generated based on the reference injection time and the target ignition interval.

[0129] S400: Based on the difference between the measured acceleration and the predicted acceleration of the engine rotor, the reference injection time and the reference ignition time are corrected in real time, and the target injection time and the target ignition time are generated and updated until the target injection time is reached at the current time.

[0130] The method for obtaining the predicted acceleration is as follows: based on the corresponding pressure reference curve, the predicted pressure at the current moment is obtained, and the acceleration prediction model outputs the corresponding predicted acceleration according to the predicted pressure.

[0131] The specific steps are as follows:

[0132] S410: Real-time detection of engine rotor speed and calculation of corresponding acceleration to obtain the corresponding measured acceleration.

[0133] S420. Based on the pressure reference curve, predict the pressure corresponding to the current moment;

[0134] The pressure reference curve here is the pressure reference curve obtained in step S221, step S222, or step S233.

[0135] S430. Based on the predicted pressure and the resistance torque corresponding to the current rotation speed, predict the acceleration at the current moment based on the acceleration prediction model to obtain the corresponding predicted acceleration;

[0136] That is, a m (t) ∝ [P m (t) - P loss (N)], where a m(t) represents the predicted acceleration at time t, P m (t) represents the predicted pressure at time t, P loss (N) is the resistance torque corresponding to the rotational speed N.

[0137] S440. Input the difference between the measured acceleration and the predicted acceleration at the current time into the PI controller, and the PI controller outputs the corresponding first time correction value;

[0138] Δa(t) = a(t) - a m (t); where a m (t) is the predicted acceleration at time t, and a(t) is the measured acceleration at time t. The difference Δa(t) is input into the PI controller, and the PI controller outputs the corresponding first-time correction value.

[0139] S450: Update the target injection time based on the first time correction value and the reference injection time;

[0140] That is, T fuel = T f0 + ΔT, where T fuel For the corresponding target injection time, T f0 ΔT represents the corresponding reference injection time, and ΔT represents the corresponding first time correction value.

[0141] S460. Update the target ignition time based on the first time correction value and the reference ignition time.

[0142] In this embodiment, the first time correction value is weighted and calculated based on a preset weighting coefficient to obtain the second time correction value; the second time correction value is superimposed with the reference ignition time to generate and update the target ignition time.

[0143] T ignition = T i0 +αΔT, where T ignition For the corresponding target ignition time, T f0 The corresponding reference ignition time is ΔT, the corresponding first time correction value is ΔT, and α is the weighting coefficient, which ranges from 0.8 to 1.2. Those skilled in the art can set it according to actual needs. In this embodiment, it is set to 1.1.

[0144] Case Study:

[0145] The drones need to take off urgently from a field airport at -40℃ to perform missions; the low temperature causes the propellant to burn at a slower rate, the gas pressure to drop to a lower peak, and the rotor to accelerate weakly; at the same time, the fuel atomization is poor and the ignition energy requirement is high at low temperatures; the failure rate of the previously fixed-sequence start-up procedure in this environment exceeds 30%.

[0146] An experiment was conducted on a small turbine engine used in a drone. It employs a solid-propellant starter (disposable) and a pyrotechnic igniter, and the type of propellant is matched with a built-in performance curve library. The specific control process is as follows:

[0147] 100. Initialization and feedforward prediction (before ignition);

[0148] Signal input: A temperature sensor detects the ambient temperature to obtain the corresponding initial loading temperature T. init = -40℃.

[0149] Model feedforward: Call the built-in performance curve library, which contains performance curves corresponding to -40℃, to obtain the corresponding pressure reference curve and acceleration reference curve;

[0150] The corresponding acceleration prediction model is obtained by fitting the pressure reference curve and the acceleration reference curve.

[0151] Based on the acceleration reference curve, the reference injection time (-40℃) is predicted to be delayed by 120 milliseconds compared to the initial injection time (+15℃). According to the deviation level corresponding to 120 milliseconds, the interval adjustment parameter is determined to be delayed by 50 milliseconds to obtain the corresponding reference ignition time.

[0152] That is, the reference injection time T f0 For T f +120ms, T f Initial injection time; reference ignition time T i0 For T i +120ms +50ms, T i This refers to the initial ignition time.

[0153] 200. Real-time towing and feedback correction (ignition process);

[0154] Start of towing: The gunpowder is triggered, and the engine rotor begins to rotate.

[0155] Feedback monitoring: The speed sensor measures the speed in real time and calculates the measured acceleration a(t).

[0156] Pressure prediction: Based on the pressure baseline curve, obtain the pressure corresponding to the current moment and obtain the corresponding predicted pressure.

[0157] Acceleration prediction: Based on the acceleration prediction model and the predicted pressure, the corresponding predicted acceleration α is obtained. m (t), that is, a m (t) ∝ [P m (t) - P loss (N)], where P m (t) represents the predicted pressure at time t, Ploss (N) is the resistance torque corresponding to the rotational speed N.

[0158] Corrected calculation: The calculation is based on the measured acceleration a(t) and the predicted acceleration a m The difference Δa(t) is calculated by the PI controller based on the integral of Δa(t), and the additional compensation ΔT = +15ms is calculated, indicating that the actual power is still slightly lower than expected.

[0159] Dynamic fine-tuning: The target injection time T output fuel =(T f0 +120ms) +15ms;

[0160] Target ignition time T ignition =T i0 +120ms +50ms +1.1 * 15ms.

[0161] The difference between the measured acceleration and the predicted acceleration Δa(t) is monitored in real time, and the reference injection time and reference ignition time are corrected in real time based on the integral of Δa(t) by the PI controller until the target injection time is reached at the current time to trigger injection.

[0162] Note: The PI controller uses the classic proportional-integral control law to obtain the corresponding ΔT.

[0163] 300, fuel injection ignition and autonomous acceleration

[0164] Based on the target injection and ignition timing, injection and ignition commands are issued sequentially. The pyrotechnic igniter successfully ignites the optimized atomized fuel at low temperatures, and the engine smoothly transitions to the autonomous acceleration phase, eventually reaching 84% speed within 9 seconds and entering closed-loop control.

[0165] At this temperature, a fixed timing program will either "flood" due to premature fuel injection or "overheat" due to insufficient power. This case study dynamically adjusts the target fuel injection timing and target ignition timing by monitoring the difference between the measured acceleration and the predicted acceleration, thereby achieving fuel injection and ignition at the optimal speed and acceleration, effectively improving the start-up success rate.

[0166] Based on the adaptive control method proposed in this embodiment, through feedforward prediction and real-time monitoring, it completely avoids safety hazards such as fuel-rich engine shutdown and hot suspension caused by insufficient power. The start-up success rate is significantly improved within the entire environmental envelope from -40℃ to +50℃. It also reduces the stringent requirements on batch consistency of gunpowder and storage temperature, improving the adaptability of the equipment and the flexibility of logistical support. In the research and development scenario, the control law development cycle is shortened by about 40%, and the number of expensive real-world environmental tests is reduced by about 70%, significantly reducing research and development costs and risks.

[0167] This application also proposes an adaptive timing control system for propellant starting in a turbine engine, including:

[0168] A temperature sensor detects the current ambient temperature to obtain the corresponding initial loading temperature;

[0169] The feedforward module is used to acquire the pressure reference curve and acceleration reference curve corresponding to the initial temperature of the propellant charge, and to construct an acceleration prediction model based on the pressure reference curve and the acceleration reference curve. The acceleration prediction model is used to characterize the mapping relationship between pressure and acceleration. Here, pressure refers to the pressure of the propellant gas and acceleration refers to the acceleration of the engine rotor. It is also used to predict the time required for the engine rotor speed to reach the ignition speed based on the acceleration reference curve, and to generate the corresponding reference injection time and reference ignition time.

[0170] The feedback module is used to correct the reference injection time and the reference ignition time in real time based on the difference between the measured acceleration and the predicted acceleration of the engine rotor, and to generate and update the target injection time and the target ignition time until the current time reaches the target injection time; wherein, the predicted acceleration is the predicted acceleration obtained by the acceleration prediction model based on the predicted pressure corresponding to the current time obtained from the pressure reference curve.

[0171] The feedback module includes:

[0172] A speed sensor is used to detect the rotational speed of the engine rotor in real time;

[0173] The first calculation unit is used to calculate the corresponding acceleration based on the rotational speed to obtain the corresponding measured acceleration;

[0174] The pressure prediction unit is used to predict the pressure at the current moment based on the pressure reference curve.

[0175] An acceleration prediction unit is used to predict the acceleration at the current moment based on the acceleration prediction model, according to the predicted pressure and the drag torque corresponding to the current rotation speed, and to obtain the corresponding predicted acceleration.

[0176] The closed-loop feedback unit is used to input the difference between the measured acceleration and the predicted acceleration at the current time into the PI controller, and the PI controller outputs the corresponding first time correction value.

[0177] The correction unit is configured to update the target injection time based on the first time correction value and the reference injection time; and to update the target ignition time based on the first time correction value and the reference ignition time.

[0178] As the device embodiment is basically similar to the method embodiment, the description is relatively simple, and relevant parts can be found in the description of the method embodiment.

[0179] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0180] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, apparatus, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0181] This invention is described with reference to flowchart illustrations and / or block diagrams of the method, terminal device (system), and computer program product according to the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing terminal device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal device, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0182] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing terminal device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0183] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal equipment, causing a series of operational steps to be performed on the computer or other programmable terminal equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable terminal equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0184] It should be noted that:

[0185] The phrase "an embodiment" or "an embodiment" used in this specification means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Therefore, the phrase "an embodiment" or "an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0186] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0187] Furthermore, it should be noted that the shapes and names of the parts and components described in the specific embodiments described in this specification may differ. All equivalent or simple variations made to the structure, features, and principles described in this patent concept are included within the protection scope of this patent. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not depart from the structure of this invention or exceed the scope defined in these claims, they should all fall within the protection scope of this invention.

Claims

1. An adaptive timing control method for propellant starting in a turbine engine, characterized in that, Includes the following steps: Detect the current ambient temperature to obtain the corresponding initial loading temperature; Obtain the pressure reference curve and acceleration reference curve corresponding to the initial temperature of the propellant charge, and construct an acceleration prediction model based on the pressure reference curve and the acceleration reference curve. The pressure reference curve is the curve of pressure changing with time; the acceleration reference curve is the curve of acceleration changing with time; the acceleration prediction model is used to characterize the mapping relationship between pressure and acceleration; wherein, pressure refers to the pressure of the propellant gas, and acceleration refers to the acceleration of the engine rotor. Based on the acceleration reference curve, the time required for the engine rotor speed to reach the ignition speed is predicted, and the corresponding reference injection time and reference ignition time are generated. Based on the difference between the measured acceleration and the predicted acceleration of the engine rotor, the reference injection time and the reference ignition time are corrected in real time to generate and update the target injection time and the target ignition time until the target injection time is reached at the current time. The method for obtaining the predicted acceleration is as follows: based on the pressure reference curve, the predicted pressure corresponding to the current moment is obtained, and the acceleration prediction model outputs the corresponding predicted acceleration according to the predicted pressure.

2. The adaptive timing control method for starting propellant in a turbine engine according to claim 1, characterized in that: The engine rotor speed is detected in real time, and the corresponding acceleration is calculated to obtain the corresponding measured acceleration; The predicted pressure at the current moment is predicted based on the pressure reference curve. Based on the predicted pressure and the drag torque corresponding to the current rotational speed, the acceleration at the current moment is predicted using the acceleration prediction model to obtain the corresponding predicted acceleration; The difference between the measured acceleration and the predicted acceleration at the current time is input into the PI controller, and the PI controller outputs the corresponding first time correction value. Update the target injection time based on the first time correction value and the reference injection time; The target ignition time is updated based on the first time correction value and the reference ignition time.

3. The adaptive timing control method for propellant starting in a turbine engine according to claim 2, characterized in that: The first time correction value is weighted and calculated based on a preset weighting coefficient to obtain the second time correction value; the target injection time is generated and updated based on the superposition of the first time correction value and the reference injection time. The second time correction value and the reference ignition time are superimposed to generate and update the target ignition time.

4. The adaptive timing control method for propellant starting in a turbine engine according to any one of claims 1 to 3, characterized in that: A library of performance curves corresponding to different types of gunpowder is provided. The library includes several sets of performance curves, and each set of performance curves corresponds to a different first reference temperature. Each set of performance curves includes a pressure-time curve and an acceleration-time curve at the corresponding first reference temperature.

5. The adaptive timing control method for propellant starting in a turbine engine according to claim 4, characterized in that, When the target propellant type does not match the preset performance curve library: Based on the preset performance curve library, obtain the pressure reference curve and acceleration reference curve corresponding to the initial charge temperature, and construct an acceleration prediction model based on the pressure reference curve and the acceleration reference curve. Obtain the gas pressure characteristics corresponding to the target gunpowder type; The pressure reference curve is corrected based on the gas pressure characteristics, and the acceleration reference curve is reconstructed based on the acceleration prediction model according to the corrected pressure reference curve. Based on the reconstructed acceleration reference curve, the time required for the engine rotor speed to reach the ignition speed is predicted, and the corresponding reference injection time and reference ignition time are generated. The predicted pressure at the current moment is predicted based on the corrected pressure baseline curve.

6. The adaptive timing control method for propellant starting in a turbine engine according to claim 5, characterized in that, The steps for obtaining the pressure reference curve and acceleration reference curve corresponding to the initial loading temperature based on the preset performance curve library are as follows: obtain the performance curve with the first reference temperature as the initial loading temperature from the preset performance curve library to obtain the corresponding pressure reference curve and acceleration reference curve. Alternatively, two sets of performance curves adjacent to the first reference temperature and the initial charge temperature can be obtained from a preset performance curve library. The pressure-time curves in the performance curves can be interpolated to obtain a pressure reference curve corresponding to the initial charge temperature. The acceleration-time curves in the performance curves can be interpolated to obtain a corresponding acceleration reference curve.

7. The adaptive timing control method for propellant starting in a turbine engine according to claim 5, characterized in that, The gas pressure characteristics include several gas pressure curves or maximum gas pressure corresponding to a second reference temperature; When the gas pressure characteristic is the gas pressure curve, the gas pressure curve corresponding to the initial charge temperature is used as the corrected pressure reference curve. When the gas pressure characteristic is the maximum gas pressure, the corresponding pressure reference curve is corrected based on the maximum gas pressure corresponding to the initial charging temperature.

8. The adaptive timing control method for starting propellant in a turbine engine according to claim 4, characterized in that... ； The initial injection time and initial ignition time are pre-configured, and the time interval between the initial injection time and the initial ignition time is used as the initial ignition interval. Several deviation levels and corresponding interval adjustment parameters are pre-configured. The deviation levels are used to indicate the direction and degree of deviation of the reference injection time relative to the initial injection time. When the corresponding reference injection time is obtained based on the corresponding acceleration reference curve: calculate the difference between the reference injection time and the initial injection time, and determine the deviation level corresponding to the reference injection time; The initial ignition interval is corrected based on the interval adjustment parameter corresponding to the deviation level to obtain the target ignition interval; A corresponding reference ignition time is generated based on the reference injection time and the target ignition interval.

9. An adaptive timing control system for propellant starting in a turbine engine, characterized in that, include: A temperature sensor detects the current ambient temperature to obtain the corresponding initial loading temperature; The feedforward module is used to acquire the pressure reference curve and acceleration reference curve corresponding to the initial temperature of the propellant charge, and to construct an acceleration prediction model based on the pressure reference curve and the acceleration reference curve. The pressure reference curve is a curve showing the change of pressure over time; the acceleration reference curve is a curve showing the change of acceleration over time; the acceleration prediction model is used to characterize the mapping relationship between pressure and acceleration; where pressure refers to the pressure of the propellant gas and acceleration refers to the acceleration of the engine rotor; it is also used to predict the time required for the engine rotor speed to reach the ignition speed based on the acceleration reference curve, and to generate the corresponding reference injection time and reference ignition time. The feedback module is used to correct the reference injection time and the reference ignition time in real time based on the difference between the measured acceleration and the predicted acceleration of the engine rotor, and to generate and update the target injection time and the target ignition time until the current time reaches the target injection time; wherein, the predicted acceleration is the predicted acceleration obtained by the acceleration prediction model based on the predicted pressure corresponding to the current time obtained from the pressure reference curve.

10. The adaptive timing control system for propellant starting in a turbine engine according to claim 9, characterized in that, The feedback module includes: a speed sensor, used to detect the speed of the engine rotor in real time; The first calculation unit is used to calculate the corresponding acceleration based on the rotational speed to obtain the corresponding measured acceleration; The pressure prediction unit is used to predict the pressure at the current moment based on the pressure reference curve. An acceleration prediction unit is used to predict the acceleration at the current moment based on the acceleration prediction model, according to the predicted pressure and the drag torque corresponding to the current rotation speed, and to obtain the corresponding predicted acceleration. The closed-loop feedback unit is used to input the difference between the measured acceleration and the predicted acceleration at the current time into the PI controller, and the PI controller outputs the corresponding first time correction value. The correction unit is configured to update the target injection time based on the first time correction value and the reference injection time; and to update the target ignition time based on the first time correction value and the reference ignition time.

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