An engine control method, an engine control device, an engine, and a rocket

Abstract

This invention provides an engine control method, an engine control device, an engine, and a rocket. The method includes: generating control commands for each control channel of the engine, wherein the control channels are: a chamber pressure control channel, a gas temperature control channel, and a mixture ratio control channel; each time the engine is controlled, at least one of the control channels uses a combination of feedforward control and feedback control based on the control command corresponding to the control channel itself to correct the valve opening of its own control channel, forming a final valve opening command corresponding to the control channel. This allows the parameters of the control channel to be adjusted according to real-time conditions, making the engine parameters as consistent as possible with preset parameter values, thereby improving the control accuracy of the engine parameters.

Description

Technical Field

[0001] This invention relates to the field of engine control, specifically to an engine control method, an engine control device, an engine, and a rocket. Background Technology

[0002] With the development of reusable liquid rocket engines and vertical takeoff and landing (VTOL) technologies for launch vehicles, the requirements for engine thrust regulation (i.e., variable thrust) and precise control of the mixture ratio are increasing. In the control system of a liquid rocket engine, the engine chamber pressure (thrust), the gas generator temperature, and the overall mixture ratio (the mass ratio of liquid oxygen to kerosene in the engine) are the three most critical controlled variables.

[0003] In the process of developing this invention, the applicant discovered that the closed-loop control of liquid rocket engines in the prior art has at least the following problems:

[0004] In liquid rocket engine control systems, the engine is typically viewed as three independent single-input single-output (SIO) systems. Each SIO system is controlled as an independent single loop. Specifically, the chamber pressure is controlled by adjusting the oxygen circuit valves based on the chamber pressure deviation, the gas generator temperature is controlled by adjusting the auxiliary combustion valves based on the temperature deviation, and the overall mixture ratio is controlled by adjusting the main combustion valve based on the mixture ratio deviation.

[0005] In existing technologies, feedforward control is introduced to improve response speed. However, most feedforward control strategies are relatively simple, employing only a static lookup table method based on the setpoint (command value). That is, based on the target parameter value, the estimated valve opening is obtained from the table as the feedforward quantity (the feedforward quantity refers to the valve angle predicted in advance by the control system). This method cannot meet the actual changes in parameters within the engine, resulting in the engine parameter adjustment still not being consistent with the preset parameter values.

[0006] Existing independent loop control lacks information exchange between channels, relying solely on feedback loops to passively adjust for this coupling effect as an "unknown disturbance." This leads to significant fluctuations in temperature and air-fuel ratio during deep or rapid shifts, resulting in long adjustment times and potentially engine damage due to exceeding temperature limits.

[0007] Therefore, ensuring that the actual parameter values ​​obtained when adjusting the engine parameters are consistent with the preset parameter values ​​is a technical problem that urgently needs to be solved.

[0008] Open-loop feedforward based on commands cannot perceive the real-time dynamic state of the system. Especially during variable-push processes, when the valve action of the main control channel (such as the chamber pressure channel) has delayed or nonlinear characteristics, if other channels only rely on commands for feedforward, it will lead to mismatch in the timing of valve actions, which will exacerbate overshoot and oscillation in the dynamic process of the system.

[0009] When the engine is under extreme operating conditions or the valve reaches its physical / mechanical limit of being fully open / closed, if the controller continues to accumulate integrals, the integral term value will be artificially high. Once the operating condition command reverses, the controller needs a long time to "de-saturate" before the valve can actuate, resulting in severe control lag and system overshoot.

[0010] High-frequency noise from sensors or minute calculation jitter in the control algorithm can cause the output command to fluctuate slightly around the target value. Although this high-frequency oscillation has little impact on fluid control, it can cause the electric servo mechanism to be in a high-frequency reciprocating micro-motion state for a long time, leading to motor overheating, accelerated gear wear, and seriously affecting the lifespan and reliability of reusable engines. Summary of the Invention

[0011] This invention provides an engine control method, an engine control device, an engine, and a rocket, which can solve the problem in the prior art that "the adjustment of engine parameters still cannot be consistent with the preset parameter values".

[0012] To achieve the above objectives, in a first aspect, embodiments of the present invention provide an engine control method, comprising:

[0013] Control commands are programmed for each control channel of the engine, namely: chamber pressure control channel, gas temperature control channel, and air-fuel mixture control channel;

[0014] Each time the engine is controlled, at least one control channel uses a combination of feedforward control and feedback control based on the control command of the control channel itself to correct the valve opening of its own control channel, thereby forming the final valve opening command corresponding to the control channel.

[0015] Secondly, embodiments of the present invention also provide an engine control device, comprising:

[0016] The control command setting unit is used to generate control commands for each control channel of the engine. The control channels are: chamber pressure control channel, gas temperature control channel and mixture ratio control channel.

[0017] The control command correction unit is used to correct the valve opening of at least one control channel each time the engine is controlled by combining feedforward control with feedback control based on the control command corresponding to the control channel itself, so as to form the final valve opening command corresponding to the control channel.

[0018] Thirdly, embodiments of the present invention also provide an engine, including the aforementioned engine control device.

[0019] Fourthly, embodiments of the present invention also provide a rocket, including one of the aforementioned engines.

[0020] The above technical solution has the following beneficial effects: Each time the engine is controlled, for one of the multiple control channels, a combination of feedforward control and feedback control based on the control command of the control channel itself is used to correct the valve opening of that control channel, forming the final valve opening command corresponding to the control channel. This allows the parameters of the control channel to be adjusted according to real-time conditions, ensuring that the engine parameters are as consistent as possible with the preset parameter values, thereby improving the control accuracy of the engine parameters.

[0021] For the chamber pressure control channel, the engine chamber pressure command is directly executed as feedforward control, and feedback control is performed based on the execution results. This allows the actual chamber pressure of the chamber pressure control channel to be adjusted according to the real-time situation, so that the actual chamber pressure of the engine is as consistent as possible with the preset chamber pressure value, thereby improving the control accuracy of the engine chamber pressure.

[0022] For the gas temperature control channel, the engine chamber pressure command is used as feedforward control to correct and execute the opening of the auxiliary combustion valve corresponding to the generator gas temperature command. The result of the execution is combined with feedback control, which can adjust the actual gas temperature of the gas temperature control channel according to the real-time situation, so that the actual gas temperature is as consistent as possible with the preset gas temperature value, thereby improving the control accuracy of the actual gas temperature.

[0023] For the air-fuel mixture control channel, the engine chamber pressure command is used as feedforward control to correct and execute the opening of the combustion valve corresponding to the oxygen auxiliary valve opening command. The result of the execution is combined with feedback control, which can adjust the actual air-fuel mixture control channel according to the real-time situation, so that the actual air-fuel mixture is as consistent as possible with the preset air-fuel mixture ratio, thereby improving the control accuracy of the actual air-fuel mixture.

[0024] As can be seen, in this embodiment of the invention, the multivariable overall control (engine chamber pressure Pc, gas temperature Tit, and mixture ratio Ke) is decoupled into three independent single-variable individual controls. Under the individual control, the output result of the engine chamber pressure control is used as the feedforward control of gas temperature and the feedforward control of mixture ratio. That is, the output result of the engine chamber pressure control is used as the input feedback to the gas temperature control, and the output result of the gas temperature control is used as the input feedback to the mixture ratio control, so as to further improve the control accuracy of the actual gas temperature and the actual mixture ratio.

[0025] The three controlled parameters—actual chamber pressure, actual fuel gas temperature, and actual mixture ratio—are integrated. The valve opening limit state refers to the maximum and minimum values. The feedforward control circuit selects different variables as inputs based on the functional requirements of different control channels. Specifically, the chamber pressure control channel uses the chamber pressure command as the feedforward input to improve the engine's variable-thrust dynamic performance; the fuel gas temperature control channel uses the oxygen auxiliary valve intermediate correction opening command given by the chamber pressure control channel as the feedforward input to reduce the disturbance of thrust control on fuel gas temperature, thereby improving temperature tracking performance during variable-thrust processes; the mixture ratio control channel also uses the oxygen auxiliary valve intermediate correction opening command as the feedforward input to reduce the disturbance of thrust control on the overall engine mixture ratio, thereby improving mixture ratio tracking performance during variable-thrust processes.

[0026] In the feedback loop, in addition to proportional and integral terms, a derivative term (D) can be introduced to form PID control, further improving the system's damping characteristics; alternatively, a fuzzy PID controller can be used, utilizing fuzzy logic to adjust the PID parameters in real time based on the magnitude of the deviation (proportional, integral, and derivative terms all have parameters). By introducing a derivative (velocity) feedforward term, a larger driving torque can be provided in the initial stage of command changes, effectively overcoming the dynamic hysteresis caused by the large volume lag of the thrust chamber of a high-thrust engine and the large inertia of the pipeline fluid. This enables the engine to quickly track high-frequency thrust variation commands issued by the host computer, improving the response speed to large inertial loads, providing high-bandwidth dynamic response support for the rocket's precise landing and attitude adjustment, and meeting the rapid adjustment requirements of the launch vehicle's vertical takeoff and landing.

[0027] To address the engine's extreme sensitivity to pressure over-limits, an anti-integral saturation module is employed, linked to the physical actuator's status. When the valve reaches its fully open or fully closed mechanical limit, the controller immediately freezes or adjusts the integral term, avoiding the artificially high integral value generated by traditional PI controllers in the saturation region. This allows the valve to respond with zero delay when control commands are reversed or the operating condition exits the saturation region, effectively suppressing potential pressure / speed overshoot that may occur at the moment of exiting saturation. This protects the engine thrust chamber and turbopump from destructive impacts, significantly improving the system's safety margin.

[0028] To improve feedforward performance, feedforward control includes valve position (proportional) and rate (derivative) control, thus requiring speed limiting of input commands. The initial amplitude and speed limiting are applied to the raw commands (engine chamber pressure command, generator gas temperature command, and generator mixture ratio command) issued by the host computer (engine controller). These commands may be abrupt; speed and amplitude limiting at the input end smooths the command and prevents overflow. The output command undergoes a second speed and amplitude limiting, as well as dead-zone processing, to prevent downstream electric servo actuators (valve servo controllers) from exceeding limits, exceeding speeds, or oscillating at high frequencies near the target value. The dead zone, due to physical structure, is the region where, after the host computer (engine controller) issues a command, the valve does not move, and the output signal is 0 or unchanged. This can be compensated for by pre-setting an offset or increasing the integral gain Ki. Dead-zone processing refers to the processing of the output end to prevent minor oscillations. Attached Figure Description

[0029] 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.

[0030] Figure 1 This is a flowchart of an engine control method according to an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the engine control method according to an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the structure of an engine control device according to an embodiment of the present invention. Detailed Implementation

[0033] 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, and 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.

[0034] like Figure 1 As shown, in conjunction with embodiments of the present invention, an engine control method is provided, comprising:

[0035] S101: To generate control commands for each control channel of the engine. The control channels are: chamber pressure control channel, gas temperature control channel, and mixture ratio control channel.

[0036] S102: Each time the engine is controlled, at least one control channel uses a combination of feedforward control and feedback control based on the control command of the control channel itself to correct the valve opening of its own control channel, thereby forming the final valve opening command corresponding to the control channel.

[0037] Each time the engine is controlled, for one of the multiple control channels, a combination of feedforward control and feedback control based on the control command of the control channel itself is used to correct the valve opening of that control channel, forming the final valve opening command corresponding to the control channel. This allows for real-time adjustment of the control channel's parameters, ensuring that the engine parameters are as close as possible to the preset parameter values, thereby improving the control accuracy of the engine parameters. This avoids the technical problem in existing technologies where "a static lookup method based solely on setpoints (command values) is used, and the estimated valve opening is obtained from the table based on the target parameters as a feedforward quantity, resulting in engine parameter adjustments still not matching the preset parameter values."

[0038] Preferably, the control commands include engine chamber pressure commands;

[0039] S102: Each time the engine is controlled, at least one control channel uses a combination of feedforward control and feedback control based on its own control commands to correct the valve opening of its own control channel, forming the final valve opening command corresponding to the control channel, including:

[0040] S102-1: The engine chamber pressure command of the chamber pressure control channel is used as the input of the feedforward control of the chamber pressure control channel. The opening degree of the valve corresponding to the chamber pressure control channel is corrected by combining the feedforward control of the chamber pressure control channel with the feedback control corresponding to the control command of the chamber pressure control channel itself, so as to obtain the final opening degree command of the oxygen auxiliary valve.

[0041] For the chamber pressure control channel, the engine chamber pressure command is directly executed as feedforward control, and feedback control is performed based on the execution results. This allows the actual chamber pressure of the chamber pressure control channel to be adjusted according to the real-time situation, so that the actual chamber pressure of the engine is as consistent as possible with the preset chamber pressure value, thereby improving the control accuracy of the engine chamber pressure.

[0042] Preferably, the engine control method further includes:

[0043] In S102, the final opening command of the oxygen auxiliary valve is used as the input for feedforward control of at least one other control channel.

[0044] By using the final opening command of the oxygen auxiliary valve as the input for feedforward control of other control channels, the control accuracy of the engine parameter values ​​corresponding to other control channels can be improved.

[0045] Preferably, S102-1: The engine chamber pressure command of the chamber pressure control channel is used as the input of the feedforward control of the chamber pressure control channel. The opening degree of the valve corresponding to the chamber pressure control channel is corrected by combining the feedforward control of the chamber pressure control channel with the feedback control corresponding to the control command of the chamber pressure control channel itself, so as to obtain the final opening degree command of the oxygen auxiliary valve, including:

[0046] S102-1-1: The engine chamber pressure command of the chamber pressure control channel is used as the input of the feedforward control of the chamber pressure control channel to form the oxygen auxiliary valve intermediate correction opening command. The actual chamber pressure of the engine is obtained by executing the oxygen auxiliary valve intermediate correction opening command through the chamber pressure control channel.

[0047] S102-1-2: Based on the chamber pressure deviation between the preset chamber pressure value carried by the intermediate correction opening command of the oxygen auxiliary valve and the actual chamber pressure, the chamber pressure deviation is used as the input of the feedback control of the chamber pressure control channel, and the final opening command of the oxygen auxiliary valve for this time is output to the chamber pressure control channel.

[0048] In the chamber pressure control channel, the oxygen auxiliary valve opening command is calculated using the engine chamber pressure command. This command carries the size of the oxygen auxiliary valve opening, enabling it to control the chamber pressure. Chamber pressure feedback primarily relies on the chamber pressure sensor. In case of sensor failure or high noise, the feedback value can be the result of multi-sensor fusion (e.g., fusing data from multiple pressure sensors using Kalman filtering), or it can incorporate the turbopump speed. It participates in feedback control as an auxiliary observation variable of ventricular pressure.

[0049] Preferably, the control commands include generator gas temperature commands;

[0050] S102: Each time the engine is controlled, at least one control channel uses a combination of feedforward control and feedback control based on its own control commands to correct the valve opening of its own control channel, forming the final valve opening command corresponding to the control channel, and also includes:

[0051] S102-2: For the gas temperature control channel, the corrected oxygen auxiliary valve opening is used as the input of the feedforward control of the gas temperature control channel. The opening of the auxiliary valve corresponding to the generator gas temperature command is corrected, and the intermediate correction opening command of the auxiliary valve is output. The actual gas temperature of the engine is obtained by executing the intermediate correction opening command of the auxiliary valve through the gas temperature control channel.

[0052] S102-3: Based on the preset gas temperature value carried by the intermediate correction opening command of the auxiliary gas valve and the actual gas temperature, the gas temperature deviation is obtained. The gas temperature deviation is used as the input of the feedback control of the gas temperature control channel to obtain the final opening command of the auxiliary gas valve for this gas temperature control channel.

[0053] In the gas temperature control channel, the generator temperature command outputs the gas auxiliary valve opening command, which carries the gas auxiliary valve opening size, thereby enabling the gas auxiliary valve to control the gas temperature.

[0054] For the gas temperature control channel, the engine chamber pressure command is used as feedforward control to correct and execute the opening of the auxiliary combustion valve corresponding to the generator gas temperature command. The result of the execution is combined with feedback control, which can adjust the actual gas temperature of the gas temperature control channel according to the real-time situation, so that the actual gas temperature is as consistent as possible with the preset gas temperature value, thereby improving the control accuracy of the actual gas temperature.

[0055] Preferably, in S102-2, for the gas temperature control channel, the corrected oxygen auxiliary valve opening is used as the input to the feedforward control of the gas temperature control channel, and the output of the intermediate corrected opening command of the auxiliary valve includes:

[0056] For the gas temperature control channel, the corrected oxygen auxiliary valve opening is used as the input of the feedforward control of the gas temperature control channel. Within the feedforward control of the gas temperature control channel, the intermediate corrected opening of the auxiliary valve is calculated in real time based on the preset chamber pressure value carried by the intermediate corrected opening command of the oxygen auxiliary valve and the original gas temperature command of the generator. The intermediate corrected opening command of the auxiliary valve is generated based on the intermediate corrected opening of the auxiliary valve and output.

[0057] S102-3: Based on the preset gas temperature value carried by the intermediate correction opening command of the auxiliary gas valve and the actual gas temperature, the gas temperature deviation is obtained. This gas temperature deviation is used as the input for the feedback control of the gas temperature control channel to obtain the final opening command of the auxiliary gas valve for this gas temperature control channel, including:

[0058] The difference between the preset gas temperature value carried by the intermediate correction opening command of the auxiliary combustion valve and the actual gas temperature of the engine is taken as the gas temperature deviation. The gas temperature deviation is used as the input of the feedback control of the gas temperature control channel. Within the feedback control of the gas temperature control channel, the intermediate correction opening of the auxiliary combustion valve is corrected according to the gas temperature deviation value. Based on the intermediate correction opening of the auxiliary combustion valve, the final opening command of the auxiliary combustion valve for this gas temperature control channel is formed and output.

[0059] Preferably, the control command includes a generator mixing ratio command;

[0060] S102: Each time the engine is controlled, at least one control channel uses a combination of feedforward control and feedback control based on its own control commands to correct the valve opening of its own control channel, forming the final valve opening command corresponding to the control channel, and also includes:

[0061] S102-4: For the mixture ratio control channel, the corrected oxygen auxiliary valve opening is used as the input of the feedforward control of the mixture ratio control channel. The opening of the main combustion valve corresponding to the generator mixture ratio command is corrected, and the intermediate correction opening command of the main combustion valve is output. The actual mixture ratio is obtained by executing the intermediate correction opening command of the main combustion valve through the mixture ratio control channel. Here, the mixture ratio refers to the ratio of the mass flow rate of fuel to the combustion-supporting gas in the engine.

[0062] S102-5: Based on the mixture ratio preset value carried by the intermediate correction opening command of the main gas valve and the actual mixture ratio, the mixture ratio deviation is obtained. The mixture ratio deviation is used as the input of the feedback control of the mixture ratio control channel, and the final opening command of the main gas valve for this time is output to the mixture ratio control channel.

[0063] In the mixture ratio control channel, the mixture ratio output fuel main valve opening command is used. The fuel main valve opening command carries the size of the fuel main valve opening, which enables the fuel main valve to control the mass flow ratio of liquid oxygen and kerosene, thereby controlling the overall mass ratio of liquid oxygen and kerosene in the engine.

[0064] For the air-fuel mixture control channel, the engine chamber pressure command is used as feedforward control to correct and execute the opening of the combustion valve corresponding to the oxygen auxiliary valve opening command. The result of the execution is combined with feedback control, which can adjust the actual air-fuel mixture control channel according to the real-time situation, so that the actual air-fuel mixture is as consistent as possible with the preset air-fuel mixture ratio, thereby improving the control accuracy of the actual air-fuel mixture.

[0065] In the mixture ratio control channel, the generator mixture ratio of the generator is adjusted because the generator mixture ratio affects the turbine temperature. This avoids drastic changes in the generator mixture ratio caused by adjusting the oxygen auxiliary valve alone, which could lead to a sharp increase in temperature and damage to the turbine.

[0066] Preferably, in S102-4, for the mixture ratio control channel, the corrected oxygen auxiliary valve opening is used as the input to the feedforward control of the mixture ratio control channel, and the output is a command to correct the intermediate opening of the main combustion valve, including:

[0067] For the mixture ratio control channel, the corrected oxygen auxiliary valve opening is used as the input of the feedforward control of the mixture ratio control channel. Within the feedforward control of the mixture ratio control channel, the intermediate corrected opening of the main combustion valve is calculated based on the chamber pressure preset value carried by the corrected oxygen auxiliary valve opening and the original mixture ratio command of the generator. Based on the intermediate corrected opening of the main combustion valve, the intermediate corrected opening command of the main combustion valve is generated and output.

[0068] S102-5: Based on the mixture ratio preset value carried by the intermediate correction opening command of the main gas valve and the actual mixture ratio, the mixture ratio deviation is obtained. The mixture ratio deviation is used as the input of the feedback control of the mixture ratio control channel, and the final opening command of the main gas valve for this mixture ratio control channel is output, including:

[0069] The difference between the preset mixture ratio value carried by the intermediate correction opening command of the main combustion valve and the actual mixture ratio of the engine is taken as the mixture ratio deviation. The mixture ratio deviation is used as the input of the feedback control of the mixture ratio control channel. Within the feedback control of the mixture ratio control channel, the intermediate correction opening of the main combustion valve is corrected based on the mixture ratio deviation. Based on the corrected intermediate correction opening of the main combustion valve, the final opening command of the main combustion valve for this mixture ratio control channel is formed and output.

[0070] As can be seen, in this embodiment of the invention, the multivariable overall control (engine chamber pressure Pc, gas temperature Tit, and mixture ratio Ke) is decoupled into three independent single-variable individual controls. Under the individual control, the output result of the engine chamber pressure control is used as the feedforward control of gas temperature and the feedforward control of mixture ratio. That is, the output result of the engine chamber pressure control is used as the input feedback to the gas temperature control, and the output result of the gas temperature control is used as the input feedback to the mixture ratio control, so as to further improve the control accuracy of the actual gas temperature and the actual mixture ratio.

[0071] Preferably, in S102, the following is also included:

[0072] S102-6: The feedback control circuit used for the feedback control of each self-control channel adopts a proportional and integral controller. Each feedback control circuit includes a derivative term connected in parallel with the integral circuit. In the derivative term, each self-control channel uses the corresponding room pressure deviation, gas temperature deviation, and mixing ratio deviation as the input of the derivative term. Fuzzy logic and the integral circuit are used to adjust the PID parameters in real time.

[0073] The feedback control circuits are a first feedback control circuit, a second feedback control circuit, and a third feedback control circuit. The first feedback control circuit, the second feedback control circuit, and the third feedback control circuit use the chamber pressure deviation, the gas temperature deviation, and the mixing ratio deviation as the inputs of their respective proportional circuits and integral circuits. The integral circuit is equipped with an anti-integral saturation module, which takes the original integral circuit output as input and processes the original integral circuit output according to the valve opening limit state.

[0074] The first, second, and third feedback control circuits all include differential terms connected in parallel with the integral circuit. The magnitudes of the chamber pressure deviation, gas temperature deviation, and mixture ratio deviation are used as inputs to the differential terms. Fuzzy logic and the integral circuit are used together to adjust the PID parameters in real time.

[0075] When the calculated control quantity exceeds the limit value, the difference before and after the limit is fed back to the input of the integrator's integrating circuit through a gain feedback.

[0076] Specifically, Feedback Control (FB) is an adjustment component based on error.

[0077] All feedback control circuits employ PI (proportional-integral) controllers, using the operating condition deviation (the difference between the command value and the feedback value) as the input to both the proportional and integral circuits. To reduce the risk of overshoot caused by the integral circuit, an anti-integral saturation module is incorporated into the integral circuit. This module takes the original integral circuit output as input and processes it based on the valve opening limit state (comparing the output command before and after limitation) to prevent the integral term from growing uncontrollably after the valve actuation saturates.

[0078] The three controlled parameters—actual chamber pressure, actual fuel gas temperature, and actual mixture ratio—are integrated. The valve opening limit state refers to the maximum and minimum values. The feedforward control circuit selects different variables as inputs based on the functional requirements of different control channels. Specifically, the chamber pressure control channel uses the chamber pressure command as the feedforward input to improve the engine's variable-thrust dynamic performance; the fuel gas temperature control channel uses the oxygen auxiliary valve intermediate correction opening command given by the chamber pressure control channel as the feedforward input to reduce the disturbance of thrust control on fuel gas temperature, thereby improving temperature tracking performance during variable-thrust processes; the mixture ratio control channel also uses the oxygen auxiliary valve intermediate correction opening command as the feedforward input to reduce the disturbance of thrust control on the overall engine mixture ratio, thereby improving mixture ratio tracking performance during variable-thrust processes.

[0079] The final angle adjustment command output by each control channel is the sum of the feedback control output and the feedforward control output. To avoid feedforward overshoot, the calculation results of the feedforward control are weighted before output.

[0080] In the feedback loop, in addition to proportional and integral terms, a derivative term (D) can be introduced to form PID control, further improving the system's damping characteristics; alternatively, a fuzzy PID controller can be used, utilizing fuzzy logic to adjust the PID parameters in real time based on the magnitude of the deviation (proportional, integral, and derivative terms all have parameters). By introducing a derivative (velocity) feedforward term, a larger driving torque can be provided in the initial stage of command changes, effectively overcoming the dynamic hysteresis caused by the large volume lag of the thrust chamber of a high-thrust engine and the large inertia of the pipeline fluid. This enables the engine to quickly track high-frequency thrust variation commands issued by the host computer, improving the response speed to large inertial loads, providing high-bandwidth dynamic response support for the rocket's precise landing and attitude adjustment, and meeting the rapid adjustment requirements of the launch vehicle's vertical takeoff and landing.

[0081] When the engine is under extreme operating conditions or the valve reaches its physical / mechanical limit of being fully open / closed, if the controller continues to accumulate integrals, the integral term will be artificially high. If the operating condition command reverses, the controller will require a long time to desaturate before the valve can actuate, resulting in severe control lag and system overshoot. A reverse calculation anti-saturation method is used. When the calculated control quantity exceeds the limit value, the difference before and after the limit is passed through a gain (tracking time constant). The reciprocal of the integral term is fed back to the integrator's input, dynamically reducing the integral term and allowing the system to exit the saturation region more quickly. Addressing the engine's extreme sensitivity to pressure over-limits, an anti-integral saturation module linked to the physical actuator's state is employed. When the valve reaches its fully open or fully closed mechanical limit, the controller immediately freezes or adjusts the integral term, avoiding the artificially high integral value generated by traditional PI controllers in the saturation region. This allows the valve to respond with zero delay when the control command reverses or the operating condition exits the saturation region, effectively suppressing potential pressure / speed overshoot during the exit from saturation, thus protecting the engine thrust chamber and turbopump from destructive impacts and significantly improving the system's safety margin. It solves the overshoot and response hysteresis problems caused by controller integral divergence under valve saturation conditions during high-flow-rate operation. It eliminates the risk of pressure overshoot under extreme operating conditions.

[0082] Preferably, for the first feedback control path, a gain scheduling strategy is adopted, that is, the proportional coefficient of the proportional path is pre-established. Integral coefficients of the integrator With room pressure command The functional relationship.

[0083] Considering the drastic changes in system gain during deep thrust variation of a high-thrust engine, the proportional coefficient in feedback control... and integral coefficient It doesn't have to be a constant value. A gain scheduling strategy is used, i.e., pre-established... , With room pressure command The functional relationship is determined by table lookup or polynomial fitting. When thrust adjustment is achieved through three control channels, the controller parameters switch smoothly in real time with the operating point to ensure control quality across the entire envelope.

[0084] Preferably, the engine control method further includes:

[0085] S103: Initial speed and amplitude limits are applied to the engine chamber pressure command, generator gas temperature, and generator mixture ratio, respectively.

[0086] S104: For a control channel, the valve opening of the control channel is corrected by combining feedforward control with feedback control based on the control command of the control channel itself. The resulting output command is then used for a second speed limit and amplitude limit, as well as dead zone processing.

[0087] The dead-time handling methods include using a fixed threshold, using hysteresis comparator logic, or using dynamic dead-time, which adaptively adjusts the dead-time threshold based on the current signal-to-noise level. A hysteresis comparator has an on and off thresholds within its dead zone, and thus a hysteresis interval.

[0088] To improve feedforward performance, feedforward control includes valve position (proportional) and rate (derivative) control, thus requiring speed limiting of input commands. The initial amplitude and speed limiting are applied to the raw commands (engine chamber pressure command, generator gas temperature command, and generator mixture ratio command) issued by the host computer (engine controller). These commands may be abrupt; speed and amplitude limiting at the input end smooths the command and prevents overflow. The output command undergoes a second speed and amplitude limiting, as well as dead-zone processing, to prevent downstream electric servo actuators (valve servo controllers) from exceeding limits, exceeding speeds, or oscillating at high frequencies near the target value. The dead zone, due to physical structure, is the region where, after the host computer (engine controller) issues a command, the valve does not move, and the output signal is 0 or unchanged. This can be compensated for by pre-setting an offset or increasing the integral gain Ki. Dead-zone processing refers to the processing of the output end to prevent minor oscillations.

[0089] High-frequency noise from sensors or minute calculation jitter in the control algorithm can cause commands to fluctuate slightly at high frequencies around the target parameter value. While this has little impact on fluid control, it keeps the engine's valve actuator (electric servo mechanism) in a state of high-frequency reciprocating micro-motion for extended periods. This leads to overheating of the electric servo mechanism, accelerated mechanical wear on gears and bearings, and severely affects the lifespan and reliability of repeatedly used engines. By comprehensively adjusting dead-zone processing, speed limiting, and amplitude limiting, invalid commands caused by high-frequency noise from sensors or minute calculation jitter in the control algorithm are effectively filtered out. This keeps the electric servo motor silent near the target parameter value instead of oscillating at high frequencies. This not only reduces the thermal load on the electric servo drive and minimizes mechanical wear on gears and bearings, but also avoids the risk of overheating failure of the actuator, extending its service life and significantly improving the reliability of the engine during long-term operation and repeated use.

[0090] Besides electric servo mechanisms, actuators can also be electro-hydraulic servo valves or pneumatic regulating valves. For different types of actuators, only the form of the output interface drive signal needs to be adjusted (such as converting angle commands to current commands or PWM duty cycles), while the core closed-loop control logic remains unchanged.

[0091] Preferably, in S102, the following is also included:

[0092] S102-7: In the feedforward control of each control channel, the input signals for feedforward control include the engine chamber pressure command and the real-time measurement value of the chamber pressure sensor. and its rate of change, or the oxidant mass flow rate estimated based on the engine's real-time flow model. .

[0093] The feedforward input for the gas temperature and mixture ratio channels uses the oxygen auxiliary valve command calculated from the chamber pressure channel. Real-time measurements from a chamber pressure sensor can also be used. and its rate of change; or the oxidant mass flow rate estimated based on the engine's real-time flow model. Any physical quantity that can characterize the thrust change trend and serve as a basis for decoupling is within the scope of protection of this invention.

[0094] Feedforward control (FF) is based on a predictive adjustment component using commands. The feedforward path can use a neural network model or a multidimensional lookup table. For example, a lightweight neural network can be trained to directly output the predicted valve decoupling compensation angle, taking the chamber pressure command and the current speed as input.

[0095] In summary, a liquid rocket engine is essentially a strongly coupled, nonlinear, multivariable system. The operation of the oxygen auxiliary valve significantly alters the oxidizer flow rate into the generator and thrust chamber, thereby causing severe coupling disturbances to the gas temperature and the overall mixture ratio.

[0096] However, in existing technologies, the engine is treated as three independent loops. This independent loop control method lacks information interaction between control channels, relying solely on feedback loops to passively adjust for this coupling effect as an unknown disturbance. Consequently, during deep thrust variation (referring to large changes in amplitude) or rapid thrust variation, when the oxygen auxiliary valve in the main control channel (such as the chamber pressure channel) exhibits delayed or nonlinear characteristics, if other control channels only rely on the valve commands corresponding to their own channels for feedforward, it will lead to a mismatch in the timing of valve actions. This exacerbates overshoot and oscillations in the dynamic process of the liquid rocket engine (after valve action, the mixture ratio, temperature, thrust, etc., exceed the target values, then return to the target values ​​after significant oscillations). This results in large fluctuations in actual gas temperature and actual mixture ratio, long adjustment times, and may even damage the engine due to excessive gas temperature.

[0097] To achieve sufficient dynamic adjustment rate and disturbance resistance for each parameter, embodiments of the present invention implement multivariable dynamic decoupling during the variable propagation process, such as... Figure 3As shown, all three control channels employ a combination of feedback and feedforward control for adjustment. Specifically, a feedforward mechanism based on the modified oxygen auxiliary valve opening output from the chamber pressure control channel is used. This means that while executing the oxygen auxiliary valve opening adjustment, the opening is simultaneously sent to the gas temperature control channel and the overall engine mixture ratio control channel. Both control channels can synchronously sense changes in the oxygen auxiliary valve opening and correct their commands accordingly. This achieves dynamic tracking, enabling predictive compensation adjustments to the gas auxiliary valve and main valve the instant the thrust adjustment command is issued, significantly improving the control accuracy of the actual gas temperature and mixture ratio. This results in smaller fluctuations in the actual gas temperature and mixture ratio during deep thrust changes (large changes) or rapid thrust changes, avoiding the risk of component burnout due to excessively high local temperatures. It ensures the engine's thermodynamic stability under a wide range of thrust changes, overcoming the limitations of single-loop control in strongly coupled systems in existing technologies. It effectively overcomes the sudden temperature change of the gas generator and the drift of the overall mixture ratio caused by drastic changes in oxidant flow during the high-flow regulation process of high-thrust engines.

[0098] The engine control does not rely on complex theoretical models, but is based on logical decoupling of physical coupling relationships. It has low computational cost, high engineering practicality and robustness, and is easy to implement on a resource-constrained onboard computer. It has also been verified by hot test.

[0099] like Figure 3 As shown, in conjunction with an embodiment of the present invention, an engine control device is provided, comprising:

[0100] The control command setting unit 21 is used to generate control commands for each control channel of the engine. The control channels are: chamber pressure control channel, gas temperature control channel and mixture ratio control channel.

[0101] The control command correction unit 22 is used to correct the valve opening of at least one control channel by combining feedforward control with feedback control based on the control command corresponding to the control channel itself each time the engine is controlled, so as to form the final valve opening command corresponding to the control channel.

[0102] Each time the engine is controlled, for one of the multiple control channels, a combination of feedforward control and feedback control based on the control command of the control channel itself is used to correct the valve opening of that control channel, forming the final valve opening command corresponding to the control channel. This allows for real-time adjustment of the control channel's parameters, ensuring that the engine parameters are as close as possible to the preset parameter values, thereby improving the control accuracy of the engine parameters. This avoids the technical problem in existing technologies where "a static lookup method based solely on setpoints (command values) is used, and the estimated valve opening is obtained from the table based on the target parameters as a feedforward quantity, resulting in engine parameter adjustments still not matching the preset parameter values."

[0103] Preferably, the control commands include engine chamber pressure commands;

[0104] The control command correction unit 22 includes a first control command correction subunit, used for:

[0105] The engine chamber pressure command of the chamber pressure control channel is used as the input of the feedforward control of the chamber pressure control channel. The opening degree of the valve corresponding to the chamber pressure control channel is corrected by combining the feedforward control of the chamber pressure control channel with the feedback control corresponding to the control command of the chamber pressure control channel itself, so as to obtain the final opening degree command of the oxygen auxiliary valve.

[0106] For the chamber pressure control channel, the engine chamber pressure command is directly executed as feedforward control, and feedback control is performed based on the execution results. This allows the actual chamber pressure of the chamber pressure control channel to be adjusted according to the real-time situation, so that the actual chamber pressure of the engine is as consistent as possible with the preset chamber pressure value, thereby improving the control accuracy of the engine chamber pressure.

[0107] Preferably, the control command correction unit 22 further includes:

[0108] The final opening command of the oxygen auxiliary valve is used as the input for feedforward control of at least one other control channel.

[0109] By using the final opening command of the oxygen auxiliary valve as the input for feedforward control of other control channels, the control accuracy of the engine parameter values ​​corresponding to other control channels can be improved.

[0110] Preferably, the first control command correction subunit includes:

[0111] The first feedforward module is used to take the engine chamber pressure command from the chamber pressure control channel as the input of the feedforward control of the chamber pressure control channel, form the oxygen auxiliary valve intermediate correction opening command, and obtain the actual chamber pressure of the engine by executing the oxygen auxiliary valve intermediate correction opening command through the chamber pressure control channel.

[0112] The first feedback module is used to take the chamber pressure deviation between the preset chamber pressure value carried by the intermediate correction opening command of the oxygen auxiliary valve and the actual chamber pressure as the input of the feedback control of the chamber pressure control channel, and output the final opening command of the oxygen auxiliary valve for this time in the chamber pressure control channel.

[0113] In the chamber pressure control channel, the oxygen auxiliary valve opening command is calculated using the engine chamber pressure command. This command carries the size of the oxygen auxiliary valve opening, enabling it to control the chamber pressure. Chamber pressure feedback primarily relies on the chamber pressure sensor. In case of sensor failure or high noise, the feedback value can be the result of multi-sensor fusion (e.g., fusing data from multiple pressure sensors using Kalman filtering), or it can incorporate the turbopump speed. It participates in feedback control as an auxiliary observation variable of ventricular pressure.

[0114] Preferably, the control commands include generator gas temperature commands;

[0115] The control command correction unit 22 further includes a second control command correction subunit, which includes:

[0116] The second feedforward module is used to take the corrected oxygen auxiliary valve opening as the input of the feedforward control of the gas temperature control channel, correct the gas auxiliary valve opening corresponding to the generator gas temperature command, output the intermediate correction opening command of the gas auxiliary valve, and obtain the actual gas temperature of the engine by executing the intermediate correction opening command of the gas auxiliary valve through the gas temperature control channel.

[0117] The second feedback module is used to obtain the gas temperature deviation based on the preset gas temperature value carried by the intermediate correction opening command of the auxiliary gas valve and the actual gas temperature. The gas temperature deviation is used as the input of the feedback control of the gas temperature control channel to obtain the final opening command of the auxiliary gas valve for this gas temperature control channel.

[0118] In the gas temperature control channel, the generator temperature command outputs the gas auxiliary valve opening command, which carries the gas auxiliary valve opening size, thereby enabling the gas auxiliary valve to control the gas temperature.

[0119] For the gas temperature control channel, the engine chamber pressure command is used as feedforward control to correct and execute the opening of the auxiliary combustion valve corresponding to the generator gas temperature command. The result of the execution is combined with feedback control, which can adjust the actual gas temperature of the gas temperature control channel according to the real-time situation, so that the actual gas temperature is as consistent as possible with the preset gas temperature value, thereby improving the control accuracy of the actual gas temperature.

[0120] Preferably, the second feedforward module is specifically used for:

[0121] For the gas temperature control channel, the corrected oxygen auxiliary valve opening is used as the input of the feedforward control of the gas temperature control channel. Within the feedforward control of the gas temperature control channel, the intermediate corrected opening of the auxiliary valve is calculated in real time based on the preset chamber pressure value carried by the intermediate corrected opening command of the oxygen auxiliary valve and the original gas temperature command of the generator. The intermediate corrected opening command of the auxiliary valve is generated based on the intermediate corrected opening of the auxiliary valve and output.

[0122] The second feedback module is specifically used for:

[0123] The difference between the preset gas temperature value carried by the intermediate correction opening command of the auxiliary combustion valve and the actual gas temperature of the engine is taken as the gas temperature deviation. The gas temperature deviation is used as the input of the feedback control of the gas temperature control channel. Within the feedback control of the gas temperature control channel, the intermediate correction opening of the auxiliary combustion valve is corrected according to the gas temperature deviation value. Based on the intermediate correction opening of the auxiliary combustion valve, the final opening command of the auxiliary combustion valve for this gas temperature control channel is formed and output.

[0124] Preferably, the control command includes a generator mixing ratio command;

[0125] The control command correction unit 22 further includes a third control command correction subunit, which includes:

[0126] The third feedforward module is used to take the corrected oxygen auxiliary valve opening as the input of the feedforward control of the mixture ratio control channel, correct the main combustion valve opening corresponding to the generator mixture ratio command, output the intermediate correction opening command of the main combustion valve, and obtain the actual mixture ratio by executing the intermediate correction opening command of the main combustion valve through the mixture ratio control channel. Here, the mixture ratio refers to the ratio of the mass flow rate of fuel to the combustion-supporting gas in the engine.

[0127] The third feedback module is used to obtain the mixing ratio deviation based on the mixing ratio preset value carried by the intermediate correction opening command of the main gas valve and the actual mixing ratio. The mixing ratio deviation is used as the input of the feedback control of the mixing ratio control channel, and the final opening command of the main gas valve for this mixing ratio control channel is output.

[0128] In the mixture ratio control channel, the mixture ratio output fuel main valve opening command is used. The fuel main valve opening command carries the size of the fuel main valve opening, which enables the fuel main valve to control the mass flow ratio of liquid oxygen and kerosene, thereby controlling the overall mass ratio of liquid oxygen and kerosene in the engine.

[0129] For the air-fuel mixture control channel, the engine chamber pressure command is used as feedforward control to correct and execute the opening of the combustion valve corresponding to the oxygen auxiliary valve opening command. The result of the execution is combined with feedback control, which can adjust the actual air-fuel mixture control channel according to the real-time situation, so that the actual air-fuel mixture is as consistent as possible with the preset air-fuel mixture ratio, thereby improving the control accuracy of the actual air-fuel mixture.

[0130] In the mixture ratio control channel, the generator mixture ratio of the generator is adjusted because the generator mixture ratio affects the turbine temperature. This avoids drastic changes in the generator mixture ratio caused by adjusting the oxygen auxiliary valve alone, which could lead to a sharp increase in temperature and damage to the turbine.

[0131] Preferably, the third feedforward module is specifically used for:

[0132] For the mixture ratio control channel, the corrected oxygen auxiliary valve opening is used as the input of the feedforward control of the mixture ratio control channel. Within the feedforward control of the mixture ratio control channel, the intermediate corrected opening of the main combustion valve is calculated based on the chamber pressure preset value carried by the corrected oxygen auxiliary valve opening and the original mixture ratio command of the generator. Based on the intermediate corrected opening of the main combustion valve, the intermediate corrected opening command of the main combustion valve is generated and output.

[0133] The third feedback module is specifically used for:

[0134] The difference between the preset mixture ratio value carried by the intermediate correction opening command of the main combustion valve and the actual mixture ratio of the engine is taken as the mixture ratio deviation. The mixture ratio deviation is used as the input of the feedback control of the mixture ratio control channel. Within the feedback control of the mixture ratio control channel, the intermediate correction opening of the main combustion valve is corrected based on the mixture ratio deviation. Based on the corrected intermediate correction opening of the main combustion valve, the final opening command of the main combustion valve for this mixture ratio control channel is formed and output.

[0135] As can be seen, in this embodiment of the invention, the multivariable overall control (engine chamber pressure Pc, gas temperature Tit, and mixture ratio Ke) is decoupled into three independent single-variable individual controls. Under the individual control, the output result of the engine chamber pressure control is used as the feedforward control of gas temperature and the feedforward control of mixture ratio. That is, the output result of the engine chamber pressure control is used as the input feedback to the gas temperature control, and the output result of the gas temperature control is used as the input feedback to the mixture ratio control, so as to further improve the control accuracy of the actual gas temperature and the actual mixture ratio.

[0136] Preferably, the control command correction unit 22 further includes:

[0137] The proportional and integral controller is located in the feedback control circuit used in the feedback control of each control channel. Each feedback control circuit includes a derivative term connected in parallel with the integral circuit. In the derivative term, each control channel uses the corresponding chamber pressure deviation, gas temperature deviation, and mixture ratio deviation as the input of the derivative term. Fuzzy logic and the integral circuit are used to adjust the PID parameters in real time.

[0138] The feedback control circuits are a first feedback control circuit, a second feedback control circuit, and a third feedback control circuit. The first feedback control circuit, the second feedback control circuit, and the third feedback control circuit use the chamber pressure deviation, the gas temperature deviation, and the mixing ratio deviation as the inputs of their respective proportional circuits and integral circuits. The integral circuit is equipped with an anti-integral saturation module, which takes the original integral circuit output as input and processes the original integral circuit output according to the valve opening limit state.

[0139] The first, second, and third feedback control circuits all include differential terms connected in parallel with the integral circuit. The magnitudes of the chamber pressure deviation, gas temperature deviation, and mixture ratio deviation are used as inputs to the differential terms. Fuzzy logic and the integral circuit are used together to adjust the PID parameters in real time.

[0140] When the calculated control quantity exceeds the limit value, the difference before and after the limit is fed back to the input of the integrator's integrating circuit through a gain feedback.

[0141] Specifically, Feedback Control (FB) is an adjustment component based on error.

[0142] All feedback control circuits employ PI (proportional-integral) controllers, using the operating condition deviation (the difference between the command value and the feedback value) as the input to both the proportional and integral circuits. To reduce the risk of overshoot caused by the integral circuit, an anti-integral saturation module is incorporated into the integral circuit. This module takes the original integral circuit output as input and processes it based on the valve opening limit state (comparing the output command before and after limitation) to prevent the integral term from growing uncontrollably after the valve actuation saturates.

[0143] The three controlled parameters—actual chamber pressure, actual fuel gas temperature, and actual mixture ratio—are integrated. The valve opening limit state refers to the maximum and minimum values. The feedforward control circuit selects different variables as inputs based on the functional requirements of different control channels. Specifically, the chamber pressure control channel uses the chamber pressure command as the feedforward input to improve the engine's variable-thrust dynamic performance; the fuel gas temperature control channel uses the oxygen auxiliary valve intermediate correction opening command given by the chamber pressure control channel as the feedforward input to reduce the disturbance of thrust control on fuel gas temperature, thereby improving temperature tracking performance during variable-thrust processes; the mixture ratio control channel also uses the oxygen auxiliary valve intermediate correction opening command as the feedforward input to reduce the disturbance of thrust control on the overall engine mixture ratio, thereby improving mixture ratio tracking performance during variable-thrust processes.

[0144] The final angle adjustment command output by each control channel is the sum of the feedback control output and the feedforward control output. To avoid feedforward overshoot, the calculation results of the feedforward control are weighted before output.

[0145] In the feedback loop, in addition to proportional and integral terms, a derivative term (D) can be introduced to form PID control, further improving the system's damping characteristics; alternatively, a fuzzy PID controller can be used, utilizing fuzzy logic to adjust the PID parameters in real time based on the magnitude of the deviation (proportional, integral, and derivative terms all have parameters). By introducing a derivative (velocity) feedforward term, a larger driving torque can be provided in the initial stage of command changes, effectively overcoming the dynamic hysteresis caused by the large volume lag of the thrust chamber of a high-thrust engine and the large inertia of the pipeline fluid. This enables the engine to quickly track high-frequency thrust variation commands issued by the host computer, improving the response speed to large inertial loads, providing high-bandwidth dynamic response support for the rocket's precise landing and attitude adjustment, and meeting the rapid adjustment requirements of the launch vehicle's vertical takeoff and landing.

[0146] When the engine is under extreme operating conditions or the valve reaches its physical / mechanical limit of being fully open / closed, if the controller continues to accumulate integrals, the integral term will be artificially high. If the operating condition command reverses, the controller will require a long time to desaturate before the valve can actuate, resulting in severe control lag and system overshoot. A reverse calculation anti-saturation method is used. When the calculated control quantity exceeds the limit value, the difference before and after the limit is passed through a gain (tracking time constant). The reciprocal of the integral term is fed back to the integrator's input, dynamically reducing the integral term and allowing the system to exit the saturation region more quickly. Addressing the engine's extreme sensitivity to pressure over-limits, an anti-integral saturation module linked to the physical actuator's state is employed. When the valve reaches its fully open or fully closed mechanical limit, the controller immediately freezes or adjusts the integral term, avoiding the artificially high integral value generated by traditional PI controllers in the saturation region. This allows the valve to respond with zero delay when the control command reverses or the operating condition exits the saturation region, effectively suppressing potential pressure / speed overshoot during the exit from saturation, thus protecting the engine thrust chamber and turbopump from destructive impacts and significantly improving the system's safety margin. It solves the overshoot and response hysteresis problems caused by controller integral divergence under valve saturation conditions during high-flow-rate operation. It eliminates the risk of pressure overshoot under extreme operating conditions.

[0147] Preferably, the first feedback control path employs a gain scheduling strategy, i.e., the proportional coefficient of the proportional path is pre-established. Integral coefficients of the integrator With room pressure command The functional relationship.

[0148] Considering the drastic changes in system gain during deep thrust variation of a high-thrust engine, the proportional coefficient in feedback control... and integral coefficient It doesn't have to be a constant value. A gain scheduling strategy is used, i.e., pre-established... , With room pressure command The functional relationship is determined by table lookup or polynomial fitting. When thrust adjustment is achieved through three control channels, the controller parameters switch smoothly in real time with the operating point to ensure control quality across the entire envelope.

[0149] Preferably, the engine control device further includes an adjustment unit for:

[0150] Initial speed and amplitude limits are applied to the engine chamber pressure command, generator gas temperature command, and generator mixture ratio, respectively.

[0151] For a control channel, a combination of feedforward control and feedback control based on the control command of the control channel itself is used to correct the valve opening of the control channel. The resulting output command is then used for a second speed limit, amplitude limit, and dead zone processing.

[0152] Dead-time handling methods include using hysteresis comparator logic or adaptively adjusting the dead-time threshold based on the current signal-to-noise level. .

[0153] The dead-time handling methods include using a fixed threshold, using hysteresis comparator logic, or using dynamic dead-time, which adaptively adjusts the dead-time threshold based on the current signal-to-noise level. A hysteresis comparator has an on and off thresholds within its dead zone, and thus a hysteresis interval.

[0154] To improve feedforward performance, feedforward control includes valve position (proportional) and rate (derivative) control, thus requiring speed limiting of input commands. The initial amplitude and speed limiting are applied to the raw commands (engine chamber pressure command, generator gas temperature command, and generator mixture ratio command) issued by the host computer (engine controller). These commands may be abrupt; speed and amplitude limiting at the input end smooths the command and prevents overflow. The output command undergoes a second speed and amplitude limiting, as well as dead-zone processing, to prevent downstream electric servo actuators from exceeding limits, exceeding speeds, or oscillating at high frequencies near the target value. The dead zone, due to physical structure, is the region where, after the host computer (engine controller) issues a command, the valve does not move, and the output signal is 0 or unchanged. This can be compensated for by pre-setting an offset or increasing the integral gain Ki. Dead-zone processing refers to the processing of the output end to prevent minor oscillations.

[0155] High-frequency noise from sensors or minute calculation jitter in the control algorithm can cause commands to fluctuate slightly at high frequencies around the target parameter value. While this has little impact on fluid control, it keeps the engine's valve actuator (electric servo mechanism) in a state of high-frequency reciprocating micro-motion for extended periods. This leads to overheating of the electric servo mechanism, accelerated mechanical wear on gears and bearings, and severely affects the lifespan and reliability of repeatedly used engines. By comprehensively adjusting dead-zone processing, speed limiting, and amplitude limiting, invalid commands caused by high-frequency noise from sensors or minute calculation jitter in the control algorithm are effectively filtered out. This keeps the electric servo motor silent near the target parameter value instead of oscillating at high frequencies. This not only reduces the thermal load on the electric servo drive and minimizes mechanical wear on gears and bearings, but also avoids the risk of overheating failure of the actuator, extending its service life and significantly improving the reliability of the engine during long-term operation and repeated use.

[0156] Preferably, in the feedforward control of each control channel, the input signals for the feedforward control include the engine chamber pressure command and the real-time measurement value of the chamber pressure sensor. and its rate of change, or the oxidant mass flow rate estimated based on the engine's real-time flow model. .

[0157] The feedforward input for the gas temperature and mixture ratio channels uses the oxygen auxiliary valve command calculated from the chamber pressure channel. Real-time measurements from a chamber pressure sensor can also be used. and its rate of change; or the oxidant mass flow rate estimated based on the engine's real-time flow model. Any physical quantity that can characterize the thrust change trend and serve as a basis for decoupling is within the scope of protection of this invention.

[0158] Feedforward control (FF) is based on a predictive adjustment component using commands. The feedforward path can use a neural network model or a multidimensional lookup table. For example, a lightweight neural network can be trained to directly output the predicted valve decoupling compensation angle, taking the chamber pressure command and the current speed as input.

[0159] In summary, a liquid rocket engine is essentially a strongly coupled, nonlinear, multivariable system. The operation of the oxygen auxiliary valve significantly alters the oxidizer flow rate into the generator and thrust chamber, thereby causing severe coupling disturbances to the gas temperature and the overall mixture ratio.

[0160] However, in existing technologies, the engine is treated as three independent loops. This independent loop control method lacks information interaction between control channels, relying solely on feedback loops to passively adjust for this coupling effect as an unknown disturbance. Consequently, during deep thrust variation (referring to large changes in amplitude) or rapid thrust variation, when the oxygen auxiliary valve in the main control channel (such as the chamber pressure channel) exhibits delayed or nonlinear characteristics, if other control channels only rely on the valve commands corresponding to their own channels for feedforward, it will lead to a mismatch in the timing of valve actions. This exacerbates overshoot and oscillations in the dynamic process of the liquid rocket engine (after valve action, the mixture ratio, temperature, thrust, etc., exceed the target values, then return to the target values ​​after significant oscillations). This results in large fluctuations in actual gas temperature and actual mixture ratio, long adjustment times, and may even damage the engine due to excessive gas temperature.

[0161] To achieve sufficient dynamic adjustment rate and disturbance resistance for each parameter, embodiments of the present invention implement multivariable dynamic decoupling during the variable propagation process, such as... Figure 2 As shown, all three control channels employ a combination of feedback and feedforward control for adjustment. Specifically, a feedforward mechanism based on the modified oxygen auxiliary valve opening output from the chamber pressure control channel is used. This means that while executing the oxygen auxiliary valve opening adjustment, the opening is simultaneously sent to the gas temperature control channel and the overall engine mixture ratio control channel. Both control channels can synchronously sense changes in the oxygen auxiliary valve opening and correct their commands accordingly. This achieves dynamic tracking, enabling predictive compensation adjustments to the gas auxiliary valve and main valve the instant the thrust adjustment command is issued, significantly improving the control accuracy of the actual gas temperature and mixture ratio. This results in smaller fluctuations in the actual gas temperature and mixture ratio during deep thrust changes (large changes) or rapid thrust changes, avoiding the risk of component burnout due to excessively high local temperatures. It ensures the engine's thermodynamic stability under a wide range of thrust changes, overcoming the limitations of single-loop control in strongly coupled systems in existing technologies. It effectively overcomes the sudden temperature change of the gas generator and the drift of the overall mixture ratio caused by drastic changes in oxidant flow during the high-flow regulation process of high-thrust engines.

[0162] The engine control does not rely on complex theoretical models, but is based on logical decoupling of physical coupling relationships. It has low computational cost, high engineering practicality and robustness, and is easy to implement on a resource-constrained onboard computer. It has also been verified by hot test.

[0163] In conjunction with embodiments of the present invention, an engine is provided, including any of the aforementioned engine control devices.

[0164] In conjunction with embodiments of the present invention, a rocket is provided, comprising any of the aforementioned engines.

[0165] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

[0166] In the above detailed description, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features of the single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, wherein each claim stands alone as a preferred embodiment of the invention.

[0167] The disclosed embodiments have been described above to enable any person skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the spirit and scope of this disclosure. Therefore, this disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

[0168] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

[0169] In one or more exemplary designs, the functions described in the embodiments of the present invention can be implemented in hardware, software, firmware, or any combination of these three. If implemented in software, these functions can be stored on a computer-readable medium or transmitted on a computer-readable medium in the form of one or more instructions or code. Computer-readable media include computer storage media and communication media that facilitate the transfer of computer programs from one place to another. Storage media can be any available media that can be accessed by a general-purpose or special-purpose computer. For example, such computer-readable media can include, but is not limited to, RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store program code in the form of instructions or data structures and other forms that can be read by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Furthermore, any connection can be suitably defined as a computer-readable medium, for example, if the software is transmitted from a website, server, or other remote resource via a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wirelessly, such as infrared, wireless, and microwave, it is also included in the defined computer-readable medium. The disks and discs mentioned include compressed disks, laser discs, optical discs, DVDs, floppy disks, and Blu-ray discs. Disks typically copy data magnetically, while discs typically copy data optically using lasers. Combinations of the above can also be contained in computer-readable media.

[0170] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An engine control method, characterized in that, include: Control commands are programmed for each control channel of the engine, namely: chamber pressure control channel, gas temperature control channel, and mixture ratio control channel; Each time the engine is controlled, at least one of the control channels uses a combination of feedforward control and feedback control based on the control command of the control channel itself to correct the valve opening of its own control channel, thereby forming the final valve opening command corresponding to the control channel.

2. The engine control method according to claim 1, characterized in that, The control commands include engine chamber pressure commands; Each time the engine is controlled, at least one of the control channels uses a combination of feedforward control and feedback control based on its own control commands to correct the valve opening of its own control channel, forming a final valve opening command corresponding to the control channel, including: The engine chamber pressure command of the chamber pressure control channel is used as the input of the feedforward control of the chamber pressure control channel. The opening degree of the valve corresponding to the chamber pressure control channel is corrected by combining the feedforward control of the chamber pressure control channel with the feedback control corresponding to the control command of the chamber pressure control channel itself, so as to obtain the final opening degree command of the oxygen auxiliary valve.

3. The engine control method according to claim 2, characterized in that, Also includes: The final opening command of the oxygen auxiliary valve is used as the input to the feedforward control of at least one other control channel.

4. The engine control method according to claim 2, characterized in that, The engine chamber pressure command of the chamber pressure control channel is used as the input of the feedforward control of the chamber pressure control channel. The opening degree of the valve corresponding to the chamber pressure control channel is corrected by combining the feedforward control of the chamber pressure control channel with the feedback control corresponding to the control command of the chamber pressure control channel itself, to obtain the final opening degree command of the oxygen auxiliary valve, including: The engine chamber pressure command of the chamber pressure control channel is used as the input of the feedforward control of the chamber pressure control channel to form the oxygen auxiliary valve intermediate correction opening command. The actual chamber pressure of the engine is obtained by executing the oxygen auxiliary valve intermediate correction opening command through the chamber pressure control channel. Based on the chamber pressure deviation between the preset chamber pressure value carried by the intermediate correction opening command of the oxygen auxiliary valve and the actual chamber pressure, the chamber pressure deviation is used as the input of the feedback control of the chamber pressure control channel, and the final opening command of the oxygen auxiliary valve for this time is output to the chamber pressure control channel.

5. The engine control method according to claim 3, characterized in that, The control commands include generator gas temperature commands; Each time the engine is controlled, at least one of the control channels uses a combination of feedforward control and feedback control based on its own control commands to correct the valve opening of its own control channel, forming a final valve opening command corresponding to the control channel, and further includes: For the gas temperature control channel, the corrected oxygen auxiliary valve opening is used as the input of the feedforward control of the gas temperature control channel. The opening of the auxiliary valve corresponding to the generator gas temperature command is corrected, and the intermediate correction opening command of the auxiliary valve is output. The actual gas temperature of the engine is obtained by executing the intermediate correction opening command of the auxiliary valve through the gas temperature control channel. The gas temperature deviation is obtained by comparing the preset gas temperature value carried by the intermediate correction opening command of the auxiliary gas valve with the actual gas temperature. The gas temperature deviation is used as the input of the feedback control of the gas temperature control channel to obtain the final opening command of the auxiliary gas valve for this gas temperature control channel.

6. The engine control method according to claim 5, characterized in that, For the gas temperature control channel, the corrected oxygen auxiliary valve opening is used as the input to the feedforward control of the gas temperature control channel, and the output is a command for the intermediate corrected opening of the auxiliary valve, including: For the gas temperature control channel, the corrected oxygen auxiliary valve opening is used as the input of the feedforward control of the gas temperature control channel. Within the feedforward control of the gas temperature control channel, the intermediate corrected opening of the auxiliary valve is calculated in real time based on the preset chamber pressure value carried by the intermediate corrected opening command of the oxygen auxiliary valve and the original gas temperature command of the generator. The intermediate corrected opening command of the auxiliary valve is generated based on the intermediate corrected opening of the auxiliary valve and output. The gas temperature deviation is obtained based on the preset gas temperature value carried by the intermediate correction opening command of the auxiliary gas valve and the actual gas temperature. This gas temperature deviation is used as the input for the feedback control of the gas temperature control channel to obtain the final opening command of the auxiliary gas valve for this current operation, including: The difference between the preset gas temperature value carried by the intermediate correction opening command of the auxiliary combustion valve and the actual gas temperature of the engine is taken as the gas temperature deviation. The gas temperature deviation is used as the input of the feedback control of the gas temperature control channel. Within the feedback control of the gas temperature control channel, the intermediate correction opening of the auxiliary combustion valve is corrected according to the gas temperature deviation value. Based on the intermediate correction opening of the auxiliary combustion valve, the final opening command of the auxiliary combustion valve for this gas temperature control channel is formed and output.

7. The engine control method according to claim 3, characterized in that, The control commands include generator mixing ratio commands; Each time the engine is controlled, at least one of the control channels uses a combination of feedforward control and feedback control based on its own control commands to correct the valve opening of its own control channel, forming a final valve opening command corresponding to the control channel, and further includes: For the mixture ratio control channel, the corrected oxygen auxiliary valve opening is used as the input of the feedforward control of the mixture ratio control channel to correct the opening of the main combustion valve corresponding to the generator mixture ratio command, and output the intermediate correction opening command of the main combustion valve. The actual mixture ratio is obtained by executing the intermediate correction opening command of the main combustion valve through the mixture ratio control channel. The mixture ratio refers to the ratio of the mass flow rate of fuel to the mass flow rate of combustion gas in the engine. The mixing ratio deviation is obtained based on the preset value of the mixing ratio carried by the intermediate correction opening command of the main combustion valve and the actual mixing ratio. The mixing ratio deviation is used as the input of the feedback control of the mixing ratio control channel, and the final opening command of the main combustion valve for this time is output by the mixing ratio control channel.

8. The engine control method according to claim 7, characterized in that, For the mixture ratio control channel, the corrected oxygen auxiliary valve opening is used as the input to the feedforward control of the mixture ratio control channel, and the output is a command to correct the intermediate opening of the main combustion valve, including: For the mixture ratio control channel, the corrected oxygen auxiliary valve opening is used as the input of the feedforward control of the mixture ratio control channel. Within the feedforward control of the mixture ratio control channel, the intermediate corrected opening of the main combustion valve is calculated based on the preset chamber pressure value carried by the corrected oxygen auxiliary valve opening and the original mixture ratio command of the generator. Based on the intermediate corrected opening of the main combustion valve, the intermediate corrected opening command of the main combustion valve is generated and output. The mixing ratio deviation is obtained based on the preset mixing ratio value carried by the intermediate correction opening command of the main combustion valve and the actual mixing ratio. This mixing ratio deviation is used as the input to the feedback control of the mixing ratio control channel, and the final opening command of the main combustion valve for this current operation is output, including: The difference between the preset mixture ratio value carried by the intermediate correction opening command of the main combustion valve and the actual mixture ratio of the engine is taken as the mixture ratio deviation. The mixture ratio deviation is used as the input of the feedback control of the mixture ratio control channel. Within the feedback control of the mixture ratio control channel, the intermediate correction opening of the main combustion valve is corrected based on the mixture ratio deviation. Based on the corrected intermediate correction opening of the main combustion valve, the final opening command of the main combustion valve for this time is formed and output by the mixture ratio control channel.

9. The engine control method according to claim 1, characterized in that, Also includes: The feedback control circuit used in the feedback control of each self-control channel adopts a proportional and integral controller. Each feedback control circuit includes a derivative term connected in parallel with the integral circuit. In the derivative term, each self-control channel uses the corresponding chamber pressure deviation, gas temperature deviation, and mixing ratio deviation as inputs to the derivative term. Fuzzy logic and the integral circuit are used to adjust the PID parameters in real time.

10. An engine control device, characterized in that, include: The control command setting unit is used to generate control commands for each control channel of the engine, namely: chamber pressure control channel, gas temperature control channel and mixture ratio control channel; The control command correction unit is used to correct the valve opening of at least one of the control channels by combining feedforward control with feedback control based on the control command corresponding to the control channel itself each time the engine is controlled, so as to form the final valve opening command corresponding to the control channel.

11. An engine, characterized in that, Includes the engine control device as described in claim 10.

12. A rocket, characterized in that, Including the engine described in claim 11.

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