A starting oil supply rule control method and device for an aviation unmanned engine

Abstract

The application relates to the technical field of aero-engines and discloses a starting fuel supply law control method and device for an aero-unmanned engine, which comprises the following steps: obtaining the rotating speed and acceleration of a target moment and a historical moment, judging whether a first switching condition is met, obtaining the power turbine inlet temperature of the target moment and the historical moment if the first switching condition is met, judging whether a second switching condition is met, obtaining the fuel given quantity and the fuel feedback quantity if the second switching condition is met, judging whether a third switching condition is met, judging whether a fourth switching condition is met based on a first time consumption, a second time consumption and a third time consumption if the third switching condition is met, judging whether a fifth switching condition is met based on the first time consumption, the second time consumption and a fourth time consumption if the fourth switching condition is met, turning into a starting third stage in advance if the fifth switching condition is met, and executing the fuel supply law of the starting third stage. Through multi-stage judgment, the application realizes timely and effective switching of the fuel supply law, avoids triggering the suspension protection, and improves the engine starting success rate.

Description

Technical Field

[0001] This invention relates to the field of aero-engine technology, specifically to a method and device for controlling the start-up fuel supply pattern of an unmanned aero-engine. Background Technology

[0002] Unmanned aerial vehicle (UAV) engines are frequently started and used in harsh and variable environments such as ice, sand, rain, snow, high altitudes, plains, high temperatures, and low temperatures. To ensure smooth starting under these conditions, the starting fuel supply pattern is crucial. The traditional starting process for UAV engines consists of three stages, each employing a different fuel supply pattern: no fuel supply in the first stage; given fuel flow control in the second stage; and given acceleration control in the third stage.

[0003] Traditional fuel supply control methods involve gradually advancing the engine through three stages of startup as the compressor rotor speed increases, executing the corresponding fuel supply pattern step by step. However, with changes in the atmospheric environment, the fuel supply pattern used in the second stage of startup is poorly adaptable to the environment. In harsh environments such as extreme cold and high altitudes, the acceleration is too slow, causing the compressor rotor speed to fail to reach the specified value within a specified time. This triggers the starter suspension protection logic, preventing a smooth transition to the third stage of startup to execute the corresponding fuel supply pattern. Even if it manages to transition to the third stage, the excessively long startup time will also trigger the starter suspension protection logic, leading to engine shutdown and startup failure.

[0004] Therefore, how to successfully start the engine by controlling the switching of the fuel supply pattern in a complex and ever-changing atmospheric environment is a problem that needs to be solved. Summary of the Invention

[0005] In view of this, the present invention provides a method and device for controlling the starting fuel supply pattern of an unmanned aircraft engine, in order to solve the problem of successfully starting the engine by controlling the switching of the fuel supply pattern in a complex and variable atmospheric environment.

[0006] In a first aspect, the present invention provides a method for controlling the start-up fuel supply pattern of an unmanned aircraft engine, the method comprising:

[0007] The rotational speed and acceleration at the target time and the historical time are obtained respectively, and it is determined whether the first switching condition is met. Both the target time and the historical time are in the second stage of the start-up of the unmanned aero engine. The second stage of start-up means that the compressor rotor speed of the unmanned aero engine is in the first preset range.

[0008] When the first switching condition is met, the power turbine inlet temperature at the target time and the historical time are obtained respectively to determine whether the second switching condition is met.

[0009] When the second switching condition is met, obtain the fuel setpoint and fuel feedback amount, and determine whether the third switching condition is met.

[0010] When the third switching condition is met, the first time of starting the first stage is obtained, the second time and the third time are determined, and based on the first time, the second time and the third time, it is determined whether the fourth switching condition is met. Starting the first stage means that the compressor rotor speed of the unmanned aero-engine is in the second preset range.

[0011] When the fourth switching condition is met, the fourth time of starting the third stage is determined, and based on the first time, the second time and the fourth time, it is determined whether the fifth switching condition is met. When the fifth switching condition is met, the unmanned aircraft engine is controlled to switch from the second stage of starting to the third stage of starting in advance, and the fuel supply pattern of the third stage of starting is executed.

[0012] This invention continuously monitors the speed and acceleration changes during the second stage of starting, enabling early identification of starting anomalies from the perspective of speed trends. When a suspension trend is observed in the speed, the trend of the turbine inlet temperature is combined to further verify the starting anomaly trend. When the engine already exhibits a starting suspension trend at both speed and temperature levels, starting suspension caused by non-environmental factors such as fuel leakage is eliminated through fuel delivery and feedback, ensuring that subsequent fuel supply adjustments are based on normal fuel supply. When there is no significant leakage in the fuel system, verification is performed from a time perspective to ensure that switching to the fuel supply pattern of the third stage of starting in advance will not trigger the starting suspension protection logic, thus improving the engine starting success rate. Through multi-level dynamic judgment, the starting suspension trend is accurately identified, determining the timing for switching from the second stage of starting to the third stage of starting in advance. In harsh environments such as extreme cold and high altitudes, the system switches to a more adaptable fuel supply pattern with given acceleration control in advance, avoiding triggering the starting suspension protection logic. This solves the problem of poor adaptability of traditional given fuel flow control, achieving timely and effective switching of the fuel supply pattern and improving the engine starting success rate.

[0013] In one optional implementation, the historical time includes a first time and a second time, where the first time is the time before the target time and the second time is the time before the first time.

[0014] Obtain the rotational speed and acceleration at the target time and historical time respectively, and determine whether the first switching condition is met, including:

[0015] Obtain the first rotational speed and first acceleration at the target time, the second rotational speed and second acceleration at the first time, and the third rotational speed and third acceleration at the second time;

[0016] When the third acceleration, the second acceleration, and the first acceleration increase sequentially, or when the absolute value of the difference between the first rotational speed and the third rotational speed is less than the first threshold, it is determined that the first condition is met.

[0017] Obtain the initial acceleration of the second stage of startup, calculate the acceleration difference between the initial acceleration and the first acceleration, and calculate the acceleration ratio between the acceleration difference and the initial acceleration;

[0018] When the acceleration ratio is not less than the second threshold, the second condition is determined to be satisfied.

[0019] If the first condition and the second condition are met, it is determined that the first switching condition is met;

[0020] If the first condition and / or the second condition are not met, it is determined that the first switching condition is not met.

[0021] This invention ensures sufficient time coverage by explicitly collecting rotational speed and acceleration data across three consecutive sampling periods: the target time, the first time, and the second time. Based on the collected data, it determines whether the first and second conditions are met, accurately identifying suspension risks in the second stage of starting. The first switching condition is deemed met only when both conditions are simultaneously satisfied, ensuring that the next stage is only initiated when a serious suspension trend is genuinely present. Conversely, if either condition is not met, the process is deemed unsatisfactory, avoiding excessive intervention in the normal starting process and contributing to a higher engine starting success rate.

[0022] In one optional implementation, when the first switching condition is met, the turbine inlet temperature at the target time and the historical time are obtained respectively, and it is determined whether the second switching condition is met, including:

[0023] When the first switching condition is met, the first power turbine inlet temperature, the second power turbine inlet temperature at the first time, and the third power turbine inlet temperature at the second time are obtained at the target time, and the first temperature acceleration, the second temperature acceleration at the first time, and the third temperature acceleration at the second time are determined at the target time.

[0024] Obtain the maximum allowable starting temperature of the power turbine, and determine the third threshold based on the maximum allowable starting temperature;

[0025] When the third temperature acceleration, the second temperature acceleration, and the first temperature acceleration increase sequentially, it is determined that the third condition is satisfied.

[0026] When the inlet temperature of the first power turbine is less than the third threshold, the fourth condition is determined to be met;

[0027] If the third and fourth conditions are met, the second switching condition is determined to be met;

[0028] If the third and / or fourth conditions are not met, it is determined that the second switching condition is not met.

[0029] This invention, after satisfying the first switching condition, collects the turbine inlet temperature to determine whether the third and fourth conditions are met, further verifying the suspension trend from a temperature trend perspective, while avoiding overheating shutdown after transitioning to the third stage. Only when both the third and fourth conditions are met is the second switching condition deemed satisfied, ensuring consistency between temperature characteristics and suspension trends, and guaranteeing thermal safety. Conversely, if either condition is not met, the judgment is terminated and the process returns to the previous step, avoiding blindly switching the fuel supply pattern when temperature characteristics are unsupported or safety hazards exist, thus improving the reliability of engine starting control.

[0030] In one optional implementation, determining whether a third switching condition is met includes:

[0031] Calculate the fuel difference between the fuel setpoint and the fuel feedback amount, and calculate the absolute value of the ratio of the fuel difference to the fuel setpoint;

[0032] When the absolute value is not greater than the fourth threshold, the third switching condition is determined to be met;

[0033] If the absolute value is greater than the fourth threshold, it is determined that the third switching condition is not met.

[0034] This invention determines whether a third switching condition is met based on the fuel supply and fuel feedback, thereby identifying whether significant fuel leakage has occurred. This ensures that subsequent fuel supply switching is based on normal fuel supply, effectively reducing the risk of start-up failure and safety accidents caused by fuel leakage.

[0035] In one alternative implementation, determining the second and third time consumption periods includes:

[0036] Obtain the equilibrium speed and the start time of the second stage of startup;

[0037] The time difference between the target time and the start time is defined as the second time consumption.

[0038] Calculate the first speed difference between the equilibrium speed and the first speed, and determine the ratio between the first speed difference and the first acceleration as the third time consumption.

[0039] This invention provides core parameters for subsequent time verification by obtaining the equilibrium speed and the start time of the second stage of startup. The time difference between the target time and the start time is determined as the second time consumption, which intuitively reflects the time consumed from entering the second stage of startup to the current target time. Furthermore, the third time consumption is determined based on the equilibrium speed and the first speed, which quantifies the estimated time required to complete the remaining process of the second stage of startup under the current acceleration state, providing core data for the subsequent judgment of the fourth switching condition.

[0040] In one optional implementation, based on the first time consumption, the second time consumption, and the third time consumption, it is determined whether the fourth switching condition is met, including:

[0041] The first time threshold is determined based on the starting suspension protection logic, and the fifth threshold is determined based on the first time threshold.

[0042] When the sum of the first, second, and third time consumptions is less than the fifth threshold, the fourth switching condition is determined to be met.

[0043] If the sum of the first, second, and third time consumptions is not less than the first time threshold, it is determined that the fourth switching condition is not met.

[0044] This invention determines whether the second stage of starting has timed out by using a first time threshold. When the sum of the first, second, and third timeouts is less than a fifth threshold, it indicates that the total time to complete the second stage of starting under the current state is sufficient. Switching to the third stage of starting earlier can effectively shorten the timeout and will not trigger the starting suspension protection logic. If the sum of the three is not less than the first time threshold, it means that even if the switch is made earlier, the starting suspension protection logic will still be triggered due to the total time exceeding the limit. By judging the timing of the fuel supply pattern switching, the starting success rate is effectively improved.

[0045] In one alternative implementation, determining the fourth time consumption for starting the third stage includes:

[0046] Obtain the ground idle speed and the preset acceleration for the third stage of startup;

[0047] Calculate the second speed difference between the ground idle speed and the first speed, and the ratio between the second speed difference and the preset acceleration;

[0048] The product of the ratio and the sixth threshold is determined as the fourth time consumption.

[0049] This invention provides data for estimating the duration of the third stage by using the ground idle speed and the preset acceleration of the third stage of startup. The fourth stage duration is calculated based on the ground idle speed, the second speed, and the sixth threshold, quantifying the difference from the current speed to the final target speed. This makes the estimation of the fourth stage duration more closely match the actual acceleration process, providing core data for determining the subsequent fifth switching condition.

[0050] In one optional implementation, based on the first time consumption, the second time consumption, and the fourth time consumption, it is determined whether the fifth switching condition is met, including:

[0051] The second time threshold is determined based on the starting suspension protection logic, and the seventh threshold is determined based on the second time threshold;

[0052] When the sum of the first, second, and fourth timeouts is less than the seventh threshold, the fifth switching condition is determined to be met.

[0053] If the sum of the first, second, and fourth timeouts is not less than the seventh threshold, then the fifth switching condition is determined not to be met.

[0054] This invention uses a second time threshold to correspond to the starting suspension protection logic, which serves as the standard for judging starting success or failure. The seventh threshold is set based on the second time threshold. When the sum of the first, second, and fourth time consumption periods is less than the seventh threshold, it indicates that after early transition to the third starting stage, the total consumption time can be controlled within a safe range, and the starting suspension protection logic can be avoided. If the sum of the three is not less than the seventh threshold, it indicates that even if the third starting stage is entered early, there is a risk of triggering the starting suspension protection logic. By judging the timing of the fuel supply pattern switching, the starting success rate is effectively improved.

[0055] Secondly, the present invention provides a starting fuel supply control device for an unmanned aircraft engine, the device comprising:

[0056] The first judgment module is used to obtain the rotational speed and acceleration at the target time and the historical time respectively, and to determine whether the first switching condition is met. Both the target time and the historical time are in the second stage of the start-up of the unmanned aero engine. The second stage of start-up means that the compressor rotor speed of the unmanned aero engine is in the first preset range.

[0057] The second judgment module is used to obtain the power turbine inlet temperature at the target time and the historical time respectively when the first switching condition is met, and to determine whether the second switching condition is met.

[0058] The third judgment module is used to obtain the fuel setpoint and fuel feedback when the second switching condition is met, and to determine whether the third switching condition is met.

[0059] The fourth judgment module is used to obtain the first time of starting the first stage when the third switching condition is met, determine the second time and the third time, and determine whether the fourth switching condition is met based on the first time, the second time and the third time. Starting the first stage means the stage when the compressor rotor speed of the unmanned aero-engine is in the second preset range.

[0060] The control module is used to determine the fourth time of the third stage of startup when the fourth switching condition is met, and to determine whether the fifth switching condition is met based on the first time, the second time and the fourth time. When the fifth switching condition is met, the control module controls the unmanned aircraft engine to switch from the second stage of startup to the third stage of startup and executes the fuel supply pattern of the third stage of startup.

[0061] Thirdly, the present invention provides a computer device, comprising: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the starting fuel supply control method for an unmanned aircraft engine as described in the first aspect or any corresponding embodiment.

[0062] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to execute the start-up fuel supply control method for an unmanned aircraft engine according to the first aspect or any corresponding embodiment described above. Attached Figure Description

[0063] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0064] Figure 1 This is a schematic diagram of the start-up curve of an unmanned aircraft engine according to an embodiment of the present invention;

[0065] Figure 2 This is a flowchart illustrating the starting fuel supply control method for an unmanned aircraft engine according to an embodiment of the present invention.

[0066] Figure 3 This is a schematic diagram of the start-up curve of another unmanned aircraft engine according to an embodiment of the present invention;

[0067] Figure 4 This is a structural block diagram of a start-up fuel supply control device for an unmanned aircraft engine according to an embodiment of the present invention.

[0068] Figure 5 This is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0070] Figure 1This is a schematic diagram of the start-up curve of an unmanned aircraft engine according to an embodiment of the present invention, such as... Figure 1 As shown, the horizontal axis (time) represents time, the vertical axis (ng) represents the compressor rotor speed, and numbers 1-4 represent start-up curves under different environments. The slope of the curve represents the compressor acceleration. The start-up process of a traditional unmanned aero-engine includes three stages:

[0071] (1) Start the first stage: Figure 1 The black line segment indicates that no oil is supplied during this stage, and the compressor is driven by the starter. The acceleration is almost the same in different environments.

[0072] (2) Start the second phase: the interval from the end of the first phase to 40%, corresponding to Figure 1 The red line segment in the diagram. 40% is typically the speed at which the turbine's torque and engine drag torque first reach equilibrium, which can be represented by n. bal This indicates that due to significant variations in starter motor performance and fuel line filling, a fuel supply pattern controlled by a given fuel flow rate is used. Using a fuel supply pattern controlled by a given acceleration could easily lead to overheating or suspension issues.

[0073] (3) Start the third stage: The condition for a normal transition from the second stage to the third stage is that ng reaches a specified value. Figure 1 For example, when ng reaches 40%, the fuel supply pattern changes from given fuel flow control to given acceleration control, corresponding to... Figure 1 The blue line segment in the image.

[0074] Figure 1 The No. 1 starting curve in the figure represents engine starting at normal temperature, with similar acceleration in the second and second stages of starting. However, with changes in the atmospheric environment, especially in harsh environments such as extreme cold and high altitudes, the drawback of the fuel supply pattern with given fuel flow control having poor environmental adaptability gradually becomes apparent. As shown in the figure, the acceleration of starting curves 1-4 gradually decreases in the second stage of starting, resulting in a prolonged starting time even though the engine can enter the third stage of starting. During the starting process, a starting suspension protection logic is set. When suspension occurs, this protection logic is triggered, which will enter the shutdown state control and control the engine to stop to protect the engine. Assume that the starting suspension protection logic has two triggering conditions: Condition 1: ng < 40% after ng enters the starting state for more than 35 seconds; Condition 2: ng < 75% after ng enters the starting state for more than 65 seconds. Here, 75% is the idle speed on the ground, which can be represented by n. idl This indicates that condition 2 is also a marker for successful startup. If ng reaches 75% within 65 seconds of entering the startup state, the startup is considered successful. The startup suspension protection logic is triggered when any of the above triggering conditions are met. Figure 1As shown in start-up curve #4, if ng still does not reach 40% after 35 seconds of start-up, condition 1 is triggered, thus triggering the start-up suspension protection logic. Even if the startup can enter the third stage, condition 2 will still be triggered due to the extended start-up time, thus triggering the start-up suspension protection logic.

[0075] Therefore, it is evident that in harsh environments such as extreme cold and high altitudes, using traditional fuel supply control methods will trigger the starting suspension protection logic, leading to starting failure. Thus, this embodiment of the invention considers that the fuel supply pattern used in the third stage of starting is more adaptable to environmental changes. By acquiring parameters and performing multi-level judgments to predict the starting trend, it determines the timing for transitioning from the second stage to the third stage of starting ahead of schedule. This achieves timely and effective switching of the fuel supply pattern, avoids triggering suspension protection, and improves the engine starting success rate.

[0076] According to an embodiment of the present invention, a method for controlling the starting fuel supply pattern of an unmanned aircraft engine is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0077] This embodiment provides a method for controlling the start-up fuel supply pattern of an unmanned aerial vehicle (UAV) engine, which can be used in the numerical control system of an UAV engine. Figure 2 This is a flowchart of a starting fuel supply control method for an unmanned aircraft engine according to an embodiment of the present invention, as shown below. Figure 2 As shown, the process includes the following steps:

[0078] Step S201: Obtain the rotational speed and acceleration at the target time and the historical time respectively, and determine whether the first switching condition is met. Both the target time and the historical time are in the second stage of the start-up of the unmanned aero-engine. The second stage of start-up means that the compressor rotor speed of the unmanned aero-engine is in the first preset range.

[0079] Specifically, the stage where the compressor rotor speed is within the first preset range (e.g., 15% to 40%), that is... Figure 1 The red line segment represents the second stage of starting, employing a fuel supply pattern controlled by a given fuel flow rate. Because this fuel supply pattern has poor environmental adaptability and is prone to triggering the starting suspension protection logic, it is necessary to identify the starting suspension trend in advance during this stage. Therefore, both the target time and the historical time must be within this stage. The engine speed and acceleration at the target time and the historical time are obtained respectively to determine whether the first switching condition is met, thus achieving early identification of starting anomalies from the perspective of engine speed trend.

[0080] Step S202: When the first switching condition is met, the turbine inlet temperature at the target time and the historical time are obtained respectively, and it is determined whether the second switching condition is met.

[0081] Specifically, when the first switching condition is met, it indicates that the compressor rotor speed exhibits a slack tendency. Another typical characteristic of slack in the second stage of startup is the slow rise of the power turbine inlet temperature Tt45. Under normal circumstances, Tt45 shows a stable upward trend during this stage, with a relatively consistent acceleration; however, when there is a risk of startup slack, the rate of increase of Tt45 will slow down significantly. Simultaneously, since the third stage of startup uses a fuel supply pattern controlled by a given acceleration, the fuel supply flow will increase significantly. To prevent Tt45 from exceeding the safety threshold due to a sudden increase in fuel quantity, leading to overheating and shutdown, it is necessary to ensure that Tt45 is at a low level before transitioning to the third stage of startup. Therefore, the power turbine inlet temperature is obtained at the target time and historical times to determine whether the second switching condition is met, further verifying the abnormal startup trend from the perspective of Tt45 trend.

[0082] Step S203: When the second switching condition is met, obtain the fuel setpoint and fuel feedback amount, and determine whether the third switching condition is met.

[0083] Specifically, when the second switching condition is met, it indicates that the engine has exhibited a starting suspension trend in terms of speed and temperature. However, besides extreme environments, abnormalities in the fuel system (such as significant fuel leakage) are also a key factor causing this suspension. Fuel leakage directly disrupts the effectiveness of the fuel supply pattern, leading to a discrepancy between the actual amount of fuel entering the combustion chamber and the control command. Switching the fuel supply pattern in this situation may exacerbate the risk of failure. Therefore, it is necessary to obtain the fuel setpoint wf and the fuel feedback quantity wfdem to determine whether the third switching condition is met, further verifying this from the perspective of fuel flow trend.

[0084] Step S204: When the third switching condition is met, the first time of starting the first stage is obtained, the second time and the third time are determined, and based on the first time, the second time and the third time, it is determined whether the fourth switching condition is met. Starting the first stage means that the compressor rotor speed of the unmanned aircraft engine is in the second preset range.

[0085] Specifically, when the third switching condition is met, it indicates that the fuel system is working normally. At this point, it is necessary to further verify from a time perspective whether the starting suspension protection logic has been triggered. More specifically, the CNC system can automatically calculate the first time of the first starting stage. The first starting stage is the stage when ng is in the second preset range (e.g., 0-15%), that is, to calculate the time taken for ng to rise from 0 to 15%. At the same time, the second and third times are determined, and based on the above three times, it is judged whether the fourth switching condition is met.

[0086] Step S205: When the fourth switching condition is met, determine the fourth time of starting the third stage, and based on the first time, the second time and the fourth time, determine whether the fifth switching condition is met. When the fifth switching condition is met, control the unmanned aircraft engine to switch from the second stage of starting to the third stage of starting in advance, and execute the fuel supply pattern of the third stage of starting.

[0087] Specifically, as can be seen from the triggering conditions of the above-mentioned starting suspension protection logic, satisfying the fourth switching condition only indicates that condition 1 will not be triggered. It is still necessary to determine whether condition 2 will be triggered based on the fifth switching condition in order to evaluate whether the start-up can be successful. When the start-up can be successfully evaluated, the start-up transitions from the second stage to the third stage in advance, and the fuel supply pattern of the given acceleration control in the third stage is executed in advance, so that the engine can start smoothly in any environment.

[0088] This invention continuously monitors the speed and acceleration changes during the second stage of starting, enabling early identification of starting anomalies from the perspective of speed trends. When a suspension trend is observed in the speed, the trend of the turbine inlet temperature is combined to further verify the starting anomaly trend. When the engine already exhibits a starting suspension trend at both speed and temperature levels, starting suspension caused by non-environmental factors such as fuel leakage is eliminated through fuel delivery and feedback, ensuring that subsequent fuel supply adjustments are based on normal fuel supply. When there is no significant leakage in the fuel system, verification is performed from a time perspective to ensure that switching to the fuel supply pattern of the third stage of starting in advance will not trigger the starting suspension protection logic, thus improving the engine starting success rate. Through multi-level dynamic judgment, the starting suspension trend is accurately identified, determining the timing for switching from the second stage of starting to the third stage of starting in advance. In harsh environments such as extreme cold and high altitudes, the system switches to a more adaptable fuel supply pattern with given acceleration control in advance, avoiding triggering the starting suspension protection logic. This solves the problem of poor adaptability of traditional given fuel flow control, achieving timely and effective switching of the fuel supply pattern and improving the engine starting success rate.

[0089] This embodiment provides a method for controlling the start-up fuel supply pattern of an unmanned aerial vehicle (UAV) engine, which can be used in the numerical control system of the aforementioned UAV engine. The method specifically includes the following steps:

[0090] Step S301: Obtain the rotational speed and acceleration at the target time and the historical time respectively, and determine whether the first switching condition is met. Both the target time and the historical time are in the second stage of the start-up of the unmanned aero-engine. The second stage of start-up means that the compressor rotor speed of the unmanned aero-engine is in the first preset range. The historical time includes the first time and the second time. The first time is the time before the target time, and the second time is the time before the first time.

[0091] Specifically, step S301 includes:

[0092] Step S3011: Obtain the first rotational speed and first acceleration at the target time, the second rotational speed and second acceleration at the first time, and the third rotational speed and third acceleration at the second time.

[0093] Specifically, assuming the target time is 'a', then the first time is 'a-1', the second time is 'a-2', and therefore the target time is at least the third sampling time after entering the second stage of startup. By acquiring the acceleration at three consecutive times, we can determine whether the acceleration shows a continuous decreasing trend, ensuring sufficient time span coverage to identify trend changes rather than instantaneous fluctuations. Optionally, the timing can be selected based on the actual situation, but it must be ensured that these times are continuous.

[0094] Step S3012: When the third acceleration, the second acceleration, and the first acceleration increase sequentially, or when the absolute value of the difference between the first rotational speed and the third rotational speed is less than the first threshold, it is determined that the first condition is met.

[0095] Specifically, assuming the sampling period is t, typically 0.024s to 0.1s, the first threshold can be 0.2% × t. Optionally, 0.2% is just an example and can be adjusted according to actual needs. When the third acceleration > the second acceleration > the first acceleration, i.e., ngdot2... a-2 >ngdot2 a-1 >ngdot2 a This indicates a decreasing trend in acceleration, reflecting a gradual weakening of power as engine speed increases, a typical dynamic characteristic of starting suspension. When the absolute value of the difference between the first and third engine speeds is less than this first threshold, i.e., |ng a -ng a-2 | <0.2%×t indicates minimal change in engine speed, almost stagnant, reflecting obstructed starting and potential suspension risk. If any of the above conditions are met, the first condition is considered satisfied, meaning a suspension tendency may exist. Suspension under extreme conditions may manifest as gradual acceleration weakness or sudden engine speed stagnation; a dual assessment is performed to improve accuracy.

[0096] Step S3013: Obtain the initial acceleration of the second stage of starting, calculate the acceleration difference between the initial acceleration and the first acceleration, and calculate the acceleration ratio between the acceleration difference and the initial acceleration.

[0097] Specifically, the initial acceleration ngdot21 at the moment of entering the second stage of startup is obtained, and the acceleration difference between it and the first acceleration at the target time is calculated. The ratio of this acceleration difference to the initial acceleration is determined as the acceleration ratio, i.e. This quantifies the rate of decrease in current acceleration compared to the initial state.

[0098] Step S3014: When the acceleration ratio is not less than the second threshold, it is determined that the second condition is met.

[0099] Specifically, assuming the second threshold is 50%, it can be adjusted according to the actual situation, and is generally taken as 40% to 70%. When this acceleration ratio is not less than the second threshold, it means that the acceleration has dropped significantly compared to when it first entered the second stage of starting, the starting power is seriously insufficient, and the suspension risk is extremely high.

[0100] Step S3015: If the first condition and the second condition are met, determine that the first switching condition is met.

[0101] Specifically, if both the first and second conditions are met simultaneously, the first switching condition is deemed met. This indicates that the engine not only shows a trend of decreasing acceleration or stagnant speed, but also that the acceleration decay has reached a significant level, reflecting a high risk of starting suspension. This provides a reliable basis for whether to switch to the third stage of starting earlier, i.e., to switch the fuel supply pattern earlier.

[0102] Step S3016: If the first condition and / or the second condition are not met, determine that the first switching condition is not met.

[0103] Specifically, if the first condition and / or the second condition are not met, it is determined that the first switching condition is not met. This indicates that the engine speed is rising normally and there is no significant risk of starting failure. At this time, no early intervention is needed; the traditional fuel supply rule based on given fuel flow control continues until the engine speed reaches n. bal Then it will naturally transition to the third stage of startup.

[0104] Step S302: When the first switching condition is met, the turbine inlet temperature at the target time and the historical time are obtained respectively, and it is determined whether the second switching condition is met.

[0105] Specifically, step S302 includes:

[0106] Step S3021: When the first switching condition is met, obtain the first power turbine inlet temperature at the target time, the second power turbine inlet temperature at the first time, and the third power turbine inlet temperature at the second time, and determine the first temperature acceleration at the target time, the second temperature acceleration at the first time, and the third temperature acceleration at the second time.

[0107] Specifically, when the first switching condition is met, there is a suspension trend at the engine speed level. Since the turbine inlet temperature is a key indicator reflecting combustion efficiency, its trend is correlated with the engine speed suspension, thus it can help verify the starting anomaly. The first turbine inlet temperature Tt45 at target time a is obtained. a The inlet temperature of the second power turbine at moment a-1 is Tt45.a-1 The inlet temperature of the third power turbine at the second moment a-2 is Tt45. a-2 At each moment, based on its value relative to the previous moment's Tt45, the corresponding temperature acceleration Tt45dot is determined to quantify the trend of Tt45 change.

[0108] Step S3022: Obtain the maximum allowable starting temperature of the power turbine, and determine the third threshold based on the maximum allowable starting temperature.

[0109] Specifically, assuming the maximum permissible starting temperature of the power turbine is Tt45. max Tt45 max The result at -100℃ is used as the third threshold. Optionally, the third threshold can be adjusted according to the actual situation, generally not exceeding Tt45. max -80℃.

[0110] Step S3023: When the third temperature acceleration, the second temperature acceleration, and the first temperature acceleration increase sequentially, it is determined that the third condition is satisfied.

[0111] Specifically, when the third temperature acceleration > the second temperature acceleration > the first temperature acceleration, i.e., Tt45dot2 a-2 >Tt45dot2 a-1 >Tt45dot2 a This indicates that Tt45 rises extremely slowly, reflecting a decrease in combustion efficiency. This is a typical characteristic of starting suspension in the temperature dimension, and the third condition is met.

[0112] Step S3024: When the inlet temperature of the first power turbine is less than the third threshold, it is determined that the fourth condition is met.

[0113] Specifically, if the current Tt45 is less than the third threshold, the fourth condition is met, ensuring that Tt45 is within a safe range when switching to the third stage of startup in advance, in order to avoid Tt45 overheating and stopping due to a sudden increase in fuel flow when switching to the third stage.

[0114] Step S3025: If the third and fourth conditions are met, determine that the second switching condition is met.

[0115] Specifically, if the third and fourth conditions are met simultaneously, the second switching condition is determined to be met, which further verifies the abnormal startup trend from the temperature dimension and reduces the risk of misjudgment.

[0116] Step S3026: If the third condition and / or the fourth condition are not met, determine that the second switching condition is not met.

[0117] Specifically, if the third condition is not met, it indicates that the temperature acceleration is not decreasing, suggesting normal combustion. If the fourth condition is not met, there is a risk of overheating if the fuel supply pattern is switched prematurely. Neither of these situations is suitable for prematurely switching to the fuel supply pattern of the third stage of starting. At this point, the process returns to step S301 to continue monitoring the next sampling time after the target time, achieving dynamic tracking of the starting process and ensuring timely intervention when there is a starting risk, thereby improving the engine starting success rate.

[0118] Step S303: When the second switching condition is met, obtain the fuel setpoint and fuel feedback amount, and determine whether the third switching condition is met.

[0119] Specifically, step S303 includes:

[0120] Step S3031: Calculate the fuel difference between the fuel setpoint and the fuel feedback amount, and calculate the absolute value of the ratio of the fuel difference to the fuel setpoint.

[0121] Specifically, the fuel setpoint (wf) refers to the predetermined fuel flow rate, while the fuel feedback (wfdem) refers to the actual fuel flow rate supplied to the engine by the fuel system's actuators. Under normal circumstances, the error between the two is minimal. However, in the event of a fuel leak, the predetermined fuel supply may leak at some point, leading to a significant reduction in the fuel entering the engine, potentially causing starting suspension or fire risks. Therefore, by obtaining and calculating the fuel difference between the two, and then calculating the absolute value of the ratio of this fuel difference to the fuel setpoint, i.e. By quantifying the degree of deviation in the fuel system, it can be determined from the perspective of fuel flow stability whether the suspension is started due to fuel leakage.

[0122] Step S3032: When the absolute value is not greater than the fourth threshold, it is determined that the third switching condition is met.

[0123] Specifically, assuming the fourth threshold is 15%, if the absolute value is not greater than the fourth threshold, then the fuel is normal, there is no fuel leak, and the third switching condition is met.

[0124] Step S3033: When the absolute value is greater than the fourth threshold, it is determined that the third switching condition is not met.

[0125] Specifically, if the absolute value exceeds the fourth threshold, indicating significant fuel leakage, even if the third stage of starting is initiated earlier to increase fuel supply, insufficient fuel will not improve acceleration performance and may even exacerbate the leakage risk. Therefore, the third switching condition is deemed unmet, and the process returns to step S301 to continue monitoring the next sampling time at the target time. This fuel flow-based judgment avoids ineffective intervention when the fuel system is abnormal, ensuring engine safety and reducing potential risks.

[0126] Step S304: When the third switching condition is met, the first time of starting the first stage is obtained, the second time and the third time are determined, and based on the first time, the second time and the third time, it is determined whether the fourth switching condition is met. Starting the first stage means that the compressor rotor speed of the unmanned aircraft engine is in the second preset range.

[0127] Specifically, step S304 includes:

[0128] Step S3041: Obtain the equilibrium speed and the start time of the second stage of starting.

[0129] Specifically, when the third switching condition is met, there is no significant leakage in the fuel system. The feasibility of switching the fuel supply pattern ahead of time needs to be verified from a time perspective. The core issue is determining whether the starting suspension protection logic will be triggered. More specifically, the equilibrium speed needs to be obtained, which is the speed at which the turbine-generated torque and the engine resistance torque first reach equilibrium. This is the threshold for transitioning from the traditional second stage of starting to the third stage, and can be represented by n. bal This indicates that the value is typically 40%. It also retrieves the time when the second stage of startup begins, i.e., the start time.

[0130] Step S3042: The time difference between the target time and the starting time is determined as the second time consumption.

[0131] Specifically, the second time t2 reflects the time already consumed in the second stage of startup and is a key parameter for assessing whether the remaining time is sufficient.

[0132] Step S3043: Calculate the first speed difference between the equilibrium speed and the first speed, and determine the ratio between the first speed difference and the first acceleration as the third time consumption.

[0133] Specifically, the third time consumption is determined by the following formula (1), representing the acceleration from the target time to n at the current acceleration. bal The estimated remaining time is used to predict the remaining time to complete the second stage of startup under the current state. If this time is too long, it may trigger startup protection, and the total time needs to be shortened by switching the fuel supply pattern in advance.

[0134]

[0135] Where t3 represents the third time spent; n bal Indicates the equilibrium rotational speed; ng a Indicates the first rotational speed at target time a; ngdot2 a This represents the first acceleration at the target time a.

[0136] Step S3044: Determine the first time threshold based on the starting suspension protection logic, and determine the fifth threshold based on the first time threshold.

[0137] Specifically, condition 1 of the starting suspension protection logic is that ng < n after ng enters the starting state for more than 35 seconds. bal The first time threshold T1 is 35 seconds. The fifth threshold is 0.7 * T1, which is a time margin parameter, providing a safety margin for early switching. Optionally, the first time threshold and 0.7 are just examples and can be adjusted according to the actual situation; the latter is generally selected within the range of 0.6 to 0.8.

[0138] Step S3045: When the sum of the first time, the second time, and the third time is less than the fifth threshold, it is determined that the fourth switching condition is met.

[0139] Specifically, when the sum of the first, second, and third time consumptions is less than the fifth threshold, i.e., t1+t2+t3<0.7*T1, it indicates that the total estimated time to complete the second stage of starting under the current state is less than the fifth threshold. If it is less than the fifth threshold, it is determined that the fourth switching condition is met, indicating that there is enough time remaining. Switching in advance can utilize the higher acceleration of the third stage of starting to shorten the total time consumption, avoid triggering condition 1, and improve the engine starting success rate.

[0140] Step S3046: If the sum of the first time consumption, the second time consumption, and the third time consumption is not less than the first time threshold, it is determined that the fourth switching condition is not met.

[0141] Specifically, if the sum of the above three times is not less than the first time threshold, i.e., t1+t2+t3≥T1, then even if the engine switches to the third stage early, the starting suspension protection logic 1 will be triggered because the total time exceeds T1, rendering the early switch meaningless. Therefore, the engine continues to execute the fuel supply rule according to the traditional given fuel flow control until the speed reaches n. bal Then it will naturally transition to the third stage of startup.

[0142] Step S305: When the fourth switching condition is met, determine the fourth time of starting the third stage, and based on the first time, the second time and the fourth time, determine whether the fifth switching condition is met. When the fifth switching condition is met, control the unmanned aircraft engine to switch from the second stage of starting to the third stage of starting in advance, and execute the fuel supply pattern of the third stage of starting.

[0143] Specifically, step S305 includes:

[0144] Step S3051: Obtain the ground idle speed and the preset acceleration for the third stage of starting.

[0145] Specifically, step S304 has verified the feasibility of switching the fuel supply pattern in advance based on condition 1 of the starting suspension protection logic. Step S305 needs to further verify the possibility of successful starting based on condition 2 of the protection logic. More specifically, the idle speed on the ground is obtained, which is the core parameter for evaluating whether the start is successful, and can be represented by n. idl This indicates that the value is typically 75%. Simultaneously, the fuel supply pattern for the third stage of startup is based on given acceleration control, obtaining its preset acceleration ngdot3.

[0146] Step S3052: Calculate the second speed difference between the ground idle speed and the first speed, and the ratio between the second speed difference and the preset acceleration.

[0147] Specifically, the difference between the idle speed on the ground and the first speed at the target time is calculated, and the ratio of this difference to the preset acceleration of the third stage of startup is calculated. This reflects the acceleration from the current speed to n according to the preset acceleration of the third stage of startup. idl The base time is used to assess the time taken to start the third stage.

[0148] Step S3053: The product of the ratio and the sixth threshold is determined as the fourth time consumption.

[0149] Specifically, the sixth threshold is 1.1, representing a time margin coefficient used to compensate for the transition time from the acceleration increase in the second stage of startup to the preset acceleration in the third stage. Optionally, the sixth threshold can be adjusted according to actual needs, generally ranging from 1.05 to 1.2. The product of the above ratio and the sixth threshold is determined as the fourth time t4, making the time estimation more closely match the actual acceleration process and improving the accuracy of time judgment.

[0150] Step S3054: Determine the second time threshold based on the starting suspension protection logic, and determine the seventh threshold based on the second time threshold.

[0151] Specifically, condition 2 of the starting suspension protection logic is that after ng enters the starting state, ng < n after 65 seconds. idl The second time threshold, T2, is 65 seconds. The seventh threshold is 0.9 * T2, which provides a safety buffer to handle sudden delays in the total time. Optionally, the second time threshold and 0.9 are just examples and can be adjusted according to actual circumstances.

[0152] Step S3055: When the sum of the first time, the second time, and the fourth time is less than the seventh threshold, it is determined that the fifth switching condition is met.

[0153] Specifically, assuming the engine transitions to the third stage of startup earlier than the target time 'a' in the second stage, the engine increases fuel supply. Therefore, the second time consumed in step S3042 is the time spent in the second stage of startup. When the sum of the first, second, and fourth times is less than the seventh threshold (i.e., t1 + t2 + t4 < 0.9 * T2), it indicates that the total estimated time for completing the entire startup process after switching the fuel supply pattern earlier is less than the seventh threshold. If it is less than the seventh threshold, the fifth switching condition is met, indicating that there is sufficient time to reach n within the second time threshold. idl This ensures a successful start-up.

[0154] Step S3056: If the sum of the first time, the second time, and the fourth time is not less than the seventh threshold, it is determined that the fifth switching condition is not met.

[0155] Specifically, if the sum of the above three time consumptions is not less than the seventh threshold, the fifth switching condition is not met. In this case, even if the fuel supply pattern is switched to the third stage of starting in advance, the starting failure may still occur because the total time is close to or exceeds T2, ultimately triggering condition 2. Therefore, the engine continues to execute the traditional fuel flow control fuel supply pattern until the speed reaches n. bal Then it will naturally transition to the third stage of startup.

[0156] In some alternative implementations, when the fifth switching condition is met, the engine transitions from the target time 'a' of the second starting stage to the third starting stage ahead of schedule, switching to a fuel supply pattern with more environmentally adaptable given acceleration control, thereby improving the engine's starting success rate in various environments.

[0157] In some alternative implementations, Figure 3 This is a schematic diagram of the start-up curve of another unmanned aircraft engine according to an embodiment of the present invention, such as... Figure 3 As shown, assuming that time a meets all the above switching conditions, then at time a, the startup third stage can be entered in advance. By accelerating with ngdot3, the startup suspension protection logic can be avoided, and the startup will ultimately succeed. Assuming that time a1 meets the first and third switching conditions, but does not meet the fourth switching condition, that is, it is predicted that if the startup third stage is entered in advance at time a1, the startup suspension protection logic 1 will still be triggered, resulting in startup failure.

[0158] This invention continuously monitors the speed and acceleration changes during the second stage of starting, enabling early identification of starting anomalies from the perspective of speed trends. When a suspension trend is observed in the speed, the trend of the turbine inlet temperature is combined to further verify the starting anomaly trend. When the engine already exhibits a starting suspension trend at both speed and temperature levels, starting suspension caused by non-environmental factors such as fuel leakage is eliminated through fuel delivery and feedback, ensuring that subsequent fuel supply adjustments are based on normal fuel supply. When there is no significant leakage in the fuel system, verification is performed from a time perspective to ensure that switching to the fuel supply pattern of the third stage of starting in advance will not trigger the starting suspension protection logic, thus improving the engine starting success rate. Through multi-level dynamic judgment, the starting suspension trend is accurately identified, determining the timing for switching from the second stage of starting to the third stage of starting in advance. In harsh environments such as extreme cold and high altitudes, the system switches to a more adaptable fuel supply pattern with given acceleration control in advance, avoiding triggering the starting suspension protection logic. This solves the problem of poor adaptability of traditional given fuel flow control, achieving timely and effective switching of the fuel supply pattern and improving the engine starting success rate.

[0159] This embodiment also provides a starting fuel supply control device for an unmanned aerial vehicle engine. This device is used to implement the above embodiments and preferred embodiments, and details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0160] This embodiment provides a starting fuel supply control device for an unmanned aerial vehicle engine, such as... Figure 4 As shown, it includes:

[0161] The first judgment module 401 is used to acquire the rotational speed and acceleration at the target time and the historical time respectively, and to determine whether the first switching condition is met. Both the target time and the historical time are in the second stage of the start-up of the unmanned aero-engine. The second stage of start-up means that the compressor rotor speed of the unmanned aero-engine is in the first preset range.

[0162] The second judgment module 402 is used to obtain the power turbine inlet temperature at the target time and the historical time respectively when the first switching condition is met, and to determine whether the second switching condition is met.

[0163] The third judgment module 403 is used to obtain the fuel setpoint and fuel feedback quantity when the second switching condition is met, and to determine whether the third switching condition is met.

[0164] The fourth judgment module 404 is used to obtain the first time of starting the first stage when the third switching condition is met, determine the second time and the third time, and determine whether the fourth switching condition is met based on the first time, the second time and the third time. Starting the first stage means the stage in which the compressor rotor speed of the unmanned aircraft engine is in the second preset range.

[0165] The control module 405 is used to determine the fourth time of starting the third stage when the fourth switching condition is met, and to determine whether the fifth switching condition is met based on the first time, the second time and the fourth time. When the fifth switching condition is met, the control module 405 controls the unmanned aircraft engine to switch from the second stage of starting to the third stage of starting in advance and executes the fuel supply pattern of the third stage of starting.

[0166] In some optional implementations, the historical moment includes a first moment and a second moment, where the first moment is the moment before the target moment and the second moment is the moment before the first moment.

[0167] The first judgment module 401 includes:

[0168] The first acquisition unit is used to acquire the first rotational speed and first acceleration at the target time, the second rotational speed and second acceleration at the first time, and the third rotational speed and third acceleration at the second time.

[0169] The first determining unit is used to determine that the first condition is met when the third acceleration, the second acceleration, and the first acceleration increase sequentially or the absolute value of the difference between the first rotational speed and the third rotational speed is less than the first threshold.

[0170] The first calculation unit is used to obtain the initial acceleration of the second stage of start-up, calculate the acceleration difference between the initial acceleration and the first acceleration, and calculate the acceleration ratio between the acceleration difference and the initial acceleration.

[0171] The second determining unit is used to determine whether the second condition is met when the acceleration ratio is not less than the second threshold.

[0172] The first condition determination unit is used to determine whether the first switching condition is met when the first condition and the second condition are met.

[0173] The second condition determination unit is used to determine that the first switching condition is not met when the first condition and / or the second condition is not met.

[0174] In some optional implementations, the second determination module 402 includes:

[0175] The second acquisition unit is used to acquire the first power turbine inlet temperature at the target time, the second power turbine inlet temperature at the first time, and the third power turbine inlet temperature at the second time when the first switching condition is met, and to determine the first temperature acceleration at the target time, the second temperature acceleration at the first time, and the third temperature acceleration at the second time.

[0176] The third acquisition unit is used to acquire the maximum allowable starting temperature of the power turbine and determine the third threshold based on the maximum allowable starting temperature.

[0177] The third determining unit is used to determine whether the third condition is satisfied when the third temperature acceleration, the second temperature acceleration, and the first temperature acceleration increase sequentially.

[0178] The fourth determining unit is used to determine whether the fourth condition is met when the inlet temperature of the first power turbine is less than the third threshold.

[0179] The third condition determination unit is used to determine whether the second switching condition is met when the third and fourth conditions are met.

[0180] The fourth condition determination unit is used to determine that the second switching condition is not met when the third condition and / or the fourth condition is not met.

[0181] In some optional implementations, the third determination module 403 includes:

[0182] The second calculation unit is used to calculate the fuel difference between the fuel setpoint and the fuel feedback amount, and to calculate the absolute value of the ratio of the fuel difference to the fuel setpoint.

[0183] The fifth condition determination unit is used to determine whether the third switching condition is met when the absolute value is not greater than the fourth threshold.

[0184] The sixth condition determination unit is used to determine that the third switching condition is not met when the absolute value is greater than the fourth threshold.

[0185] In some optional implementations, the fourth determination module 404 includes:

[0186] The fourth acquisition unit is used to acquire the balancing speed and the start time of the second stage of startup.

[0187] The fifth determining unit is used to determine the time difference between the target time and the starting time as the second time consumption.

[0188] The third calculation unit is used to calculate the first speed difference between the equilibrium speed and the first speed, and to determine the ratio between the first speed difference and the first acceleration as the third time consumption.

[0189] In some optional implementations, the fourth determination module 404 includes:

[0190] The sixth determining unit is used to determine a first time threshold based on the starting suspension protection logic, and to determine a fifth threshold based on the first time threshold.

[0191] The seventh condition determination unit is used to determine whether the fourth switching condition is met when the sum of the first time consumption, the second time consumption, and the third time consumption is less than the fifth threshold.

[0192] The eighth condition determination unit is used to determine that the fourth switching condition is not met when the sum of the first time consumption, the second time consumption, and the third time consumption is not less than the first time threshold.

[0193] In some alternative implementations, the control module 405 includes:

[0194] The fifth acquisition unit is used to acquire the ground idle speed and the preset acceleration for the third stage of startup.

[0195] The fourth calculation unit is used to calculate the second speed difference between the ground idle speed and the first speed, and the ratio between the second speed difference and the preset acceleration.

[0196] The seventh determining unit is used to determine the fourth time consumption by multiplying the ratio by the sixth threshold.

[0197] In some alternative implementations, the control module 405 includes:

[0198] The eighth determining unit is used to determine the second time threshold based on the starting suspension protection logic, and to determine the seventh threshold based on the second time threshold.

[0199] The ninth condition determination unit is used to determine whether the fifth switching condition is met when the sum of the first time consumption, the second time consumption, and the fourth time consumption is less than the seventh threshold.

[0200] The tenth condition determination unit is used to determine that the fifth switching condition is not met when the sum of the first time consumption, the second time consumption, and the fourth time consumption is not less than the seventh threshold.

[0201] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0202] In this embodiment, the start-up fuel supply control device for the unmanned aerial vehicle engine is presented in the form of a functional unit. Here, a unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0203] This invention also provides a computer device having the above-described features. Figure 4 The image shows a start-up fuel supply control device for an unmanned aircraft engine.

[0204] Please see Figure 5 , Figure 5 This is a schematic diagram of the structure of a computer device provided in an optional embodiment of the present invention, such as... Figure 5 As shown, the computer device includes one or more processors 10, memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processors can process instructions executed within the computer device, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple computer devices can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 5 Take a processor 10 as an example.

[0205] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GDA), or any combination thereof.

[0206] The memory 20 stores instructions executable by at least one processor 10 to cause at least one processor 10 to perform the method shown in the above embodiments.

[0207] The memory 20 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the computer device. Furthermore, the memory 20 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 20 may optionally include memory remotely located relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0208] The memory 20 may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0209] The computer device also includes a communication interface 30 for communicating with other devices or communication networks.

[0210] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods shown in the above embodiments.

[0211] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0212] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for controlling the starting fuel supply pattern of an unmanned aircraft engine, characterized in that, The method includes: The rotational speed and acceleration at the target time and the historical time are obtained respectively, and it is determined whether the first switching condition is met. The target time and the historical time are both located in the second stage of the start-up of the unmanned aero engine. The second stage of start-up indicates that the compressor rotor speed of the unmanned aero engine is in the first preset range. The historical time includes a first time and a second time. The first time is the time before the target time, and the second time is the time before the first time. When the first switching condition is met, the power turbine inlet temperature at the target time and the historical time are obtained respectively to determine whether the second switching condition is met. When the second switching condition is met, the fuel input and fuel feedback are obtained, and it is determined whether the third switching condition is met. When the third switching condition is met, the first time of the first stage of starting is obtained, the second time and the third time are determined, and based on the first time, the second time and the third time, it is determined whether the fourth switching condition is met. The first stage of starting means the stage in which the compressor rotor speed of the unmanned aircraft engine is in the second preset range. When the fourth switching condition is met, the fourth time of starting the third stage is determined, and based on the first time, the second time and the fourth time, it is determined whether the fifth switching condition is met. When the fifth switching condition is met, the unmanned aircraft engine is controlled to switch from the second stage of starting to the third stage of starting in advance, and the fuel supply pattern of the third stage of starting is executed. The step of obtaining the turbine inlet temperature at the target time and the historical time when the first switching condition is met, and determining whether the second switching condition is met, includes: When the first switching condition is met, the first power turbine inlet temperature at the target time, the second power turbine inlet temperature at the first time, and the third power turbine inlet temperature at the second time are obtained, and the first temperature acceleration at the target time, the second temperature acceleration at the first time, and the third temperature acceleration at the second time are determined. Obtain the maximum allowable starting temperature of the power turbine, and determine a third threshold based on the maximum allowable starting temperature; When the third temperature acceleration, the second temperature acceleration, and the first temperature acceleration increase sequentially, it is determined that the third condition is satisfied; When the inlet temperature of the first power turbine is less than the third threshold, it is determined that the fourth condition is met; When the third and fourth conditions are met, it is determined that the second switching condition is met; If the third condition and / or the fourth condition are not met, it is determined that the second switching condition is not met; The step of determining whether the fourth switching condition is met based on the first time consumption, the second time consumption, and the third time consumption includes: A first time threshold is determined based on the starting suspension protection logic, and a fifth threshold is determined based on the first time threshold; When the sum of the first time consumption, the second time consumption, and the third time consumption is less than the fifth threshold, it is determined that the fourth switching condition is met; If the sum of the first time consumption, the second time consumption, and the third time consumption is not less than the first time threshold, it is determined that the fourth switching condition is not met.

2. The method according to claim 1, characterized in that, The step of acquiring the rotational speed and acceleration at the target time and the historical time respectively, and determining whether the first switching condition is met, includes: Obtain the first rotational speed and first acceleration at the target time, the second rotational speed and second acceleration at the first time, and the third rotational speed and third acceleration at the second time; When the third acceleration, the second acceleration, and the first acceleration increase sequentially, or when the absolute value of the difference between the first rotational speed and the third rotational speed is less than a first threshold, it is determined that the first condition is met. Obtain the initial acceleration of the second stage of startup, calculate the acceleration difference between the initial acceleration and the first acceleration, and calculate the acceleration ratio between the acceleration difference and the initial acceleration; When the acceleration ratio is not less than the second threshold, it is determined that the second condition is satisfied; When the first condition and the second condition are met, it is determined that the first switching condition is met; If the first condition and / or the second condition are not met, it is determined that the first switching condition is not met.

3. The method according to claim 1, characterized in that, The determination of whether the third switching condition is met includes: Calculate the fuel difference between the fuel setpoint and the fuel feedback amount, and calculate the absolute value of the ratio of the fuel difference to the fuel setpoint; When the absolute value is not greater than the fourth threshold, it is determined that the third switching condition is met; When the absolute value is greater than the fourth threshold, it is determined that the third switching condition is not met.

4. The method according to claim 2, characterized in that, The determination of the second and third time consumption includes: Obtain the equilibrium speed and the start time of the second stage of startup; The time difference between the target time and the starting time is determined as the second time consumption; Calculate the first speed difference between the equilibrium speed and the first speed, and determine the ratio between the first speed difference and the first acceleration as the third time consumption.

5. The method according to claim 2, characterized in that, The determination of the fourth time consumption for the third stage of startup includes: Obtain the ground idle speed and the preset acceleration of the third stage of startup; Calculate the second speed difference between the ground idle speed and the first speed, and the ratio between the second speed difference and the preset acceleration; The product of the ratio and the sixth threshold is determined as the fourth time consumption.

6. The method according to claim 1, characterized in that, The step of determining whether the fifth switching condition is met based on the first time consumption, the second time consumption, and the fourth time consumption includes: A second time threshold is determined based on the starting suspension protection logic, and a seventh threshold is determined based on the second time threshold; When the sum of the first time consumption, the second time consumption, and the fourth time consumption is less than the seventh threshold, it is determined that the fifth switching condition is met; If the sum of the first time consumption, the second time consumption, and the fourth time consumption is not less than the seventh threshold, it is determined that the fifth switching condition is not met.

7. A starting fuel supply control device for an unmanned aircraft engine, characterized in that, The device includes: The first judgment module is used to acquire the rotational speed and acceleration at the target time and the historical time respectively, and to determine whether the first switching condition is met. The target time and the historical time are both located in the second stage of the start-up of the unmanned aero engine. The second stage of start-up indicates that the compressor rotor speed of the unmanned aero engine is in the first preset range. The historical time includes a first time and a second time. The first time is the time before the target time, and the second time is the time before the first time. The second judgment module is used to obtain the power turbine inlet temperature at the target time and the historical time respectively when the first switching condition is met, and to determine whether the second switching condition is met. The third judgment module is used to obtain the fuel setpoint and fuel feedback when the second switching condition is met, and to determine whether the third switching condition is met. The fourth judgment module is used to obtain the first time of the first stage of starting when the third switching condition is met, determine the second time and the third time, and determine whether the fourth switching condition is met based on the first time, the second time and the third time. The first stage of starting refers to the stage in which the compressor rotor speed of the unmanned aero-engine is in the second preset range. The control module is used to determine the fourth time of the third stage of startup when the fourth switching condition is met, and to determine whether the fifth switching condition is met based on the first time, the second time and the fourth time. When the fifth switching condition is met, the control module controls the unmanned aircraft engine to switch from the second stage of startup to the third stage of startup in advance and executes the fuel supply pattern of the third stage of startup. The second judgment module includes: The second acquisition unit is used to acquire the first power turbine inlet temperature at the target time, the second power turbine inlet temperature at the first time, and the third power turbine inlet temperature at the second time when the first switching condition is met, and to determine the first temperature acceleration at the target time, the second temperature acceleration at the first time, and the third temperature acceleration at the second time. The third acquisition unit is used to acquire the maximum allowable starting temperature of the power turbine and determine a third threshold based on the maximum allowable starting temperature. The third determining unit is used to determine that the third condition is met when the third temperature acceleration, the second temperature acceleration, and the first temperature acceleration increase sequentially. The fourth determining unit is used to determine that the fourth condition is met when the inlet temperature of the first power turbine is less than the third threshold. The third condition determination unit is used to determine that the second switching condition is met when the third condition and the fourth condition are met; The fourth condition determination unit is used to determine that the second switching condition is not met when the third condition and / or the fourth condition is not met; The fourth judgment module includes: The sixth determining unit is used to determine a first time threshold based on the starting suspension protection logic, and to determine a fifth threshold based on the first time threshold; The seventh condition determination unit is used to determine that the fourth switching condition is met when the sum of the first time consumption, the second time consumption, and the third time consumption is less than the fifth threshold. The eighth condition determination unit is used to determine that the fourth switching condition is not met when the sum of the first time consumption, the second time consumption, and the third time consumption is not less than the first time threshold.

8. A computer device, characterized in that, include: The system includes a memory and a processor, which are interconnected. The memory stores computer instructions, and the processor executes the computer instructions to perform the start-up fuel supply control method for any one of claims 1 to 6.

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