A Safety Protection Design Method for Adaptive Augmentation Controller of Launch Vehicle

Abstract

The present invention discloses a safety protection design method for an adaptive augmented controller of a launch vehicle, comprising simplifying the error term of the adaptive augmented controller to obtain a single-input-output AAC controller; simplifying the parameter angular rate deviation Δω, the error term e of the error term loop and the damping term loop of the single-input-output AAC controller; and simplifying the parameter angular rate deviation Δω, the error term e of the error term loop and the damping term loop of the single-input-output AAC controller. r , launch vehicle attitude angle and damping term y s The signal is limited; the output channel of the output circuit is limited, and the output change rate of the AAC controller is limited; a trigger access mechanism is set for the output change rate of the single-input-output AAC controller. This invention designs a safety protection design method for an adaptive augmentation controller for launch vehicles, solving the safety protection design problem of launch vehicles using adaptive augmentation controllers, achieving beneficial, harmless, simple, flexible, and reliable engineering application effects.

Description

Technical Field

[0001] This invention relates to a safety protection design method for an adaptive augmentation controller of a launch vehicle, belonging to the field of spacecraft control technology. Background Technology

[0002] During launch vehicle flight, they are subjected to complex superimposed interference from different frequency bands and intensities. Furthermore, launch vehicles have a relatively low overload tolerance and are more sensitive to interference than other spacecraft. When the rocket body is subjected to external interference, it is necessary to increase the control bandwidth to cope. However, for situations where the control signal changes too rapidly and the bandwidth is too high, there is a problem of weak adaptability. Therefore, when applying AAC control technology to launch vehicles, it is necessary to design the AAC controller with safety features tailored to the characteristics of the controlled object. This includes limiting the input and output of each loop, limiting the AAC controller output value and rate of change, and the AAC controller trigger switching mechanism.

[0003] Currently, adaptive augmentation controllers (AADCs) are not widely used in the field of launch vehicles, and there are still no clear industry standards or successful case studies available for related safety protection design methods. Publicly available literature generally only emphasizes limiting the output signal of the AADC, without any other safety protection measures. This limiting design only provides simple protection for the output layer of the AADC, ensuring its boundedness. However, it lacks any effective protection measures for the frequency characteristics of the output signal, making it unsuitable for the flight application requirements of launch vehicles. Furthermore, this method cannot protect the entire AADC output through local isolation or limiting measures when a branch of the AADC malfunctions, nor can it achieve autonomous switching functionality of the AADC when necessary. In summary, existing methods still have room for improvement. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a safety protection design method for an adaptive augmented controller for launch vehicles. The method adjusts the structure of the AAC controller and implements protection design for each loop, thereby solving the safety protection design problem of launch vehicles using adaptive augmented controllers and achieving beneficial, harmless, simple, flexible and reliable engineering application effects.

[0005] The technical solution of this invention is: a safety protection design method for an adaptive augmentation controller of a launch vehicle, wherein:

[0006] Adjusting the error term of the adaptive augmentation controller yields a single-input-output adaptive augmentation controller, denoted as the AAC controller.

[0007] For the error term loop and damping term loop of a single-input-output AAC controller, the parameter angular rate deviation Δω and error term e are... r Launch vehicle attitude angle and damping term y s Signal amplitude limiting design;

[0008] Limit the output channel of the output circuit and limit the output rate of change of the AAC controller;

[0009] Set a trigger access mechanism for the output change rate of a single-input-output AAC controller.

[0010] Preferably, a single-input-output AAC controller is as follows:

[0011] The expression for the AAC controller output loop signal is:

[0012]

[0013] k t =k a +k0

[0014] Where, k t To adapt the final output coefficients, k a k is the integral part of the output coefficients, and k0 is the constant part of the output coefficients; For k a The derivative of k tmax e represents the upper limit of the output coefficient amplitude. r The error term represents the deviation value of the reference model; y s , where is the damping term, representing the filter value of the spectral damper; 'a' is the weight of the error term, 'c' is the weight of the damping term, and 'β' is the weight of the regression term.

[0015] The formula for the damping term is:

[0016] y s =D(G(y3)) 2 )

[0017]

[0018] The formula for defining the error term is:

[0019]

[0020] Where a0 and a1 are both constant coefficients, Δω represents the launch vehicle attitude angle and angular rate deviation, respectively, and G(·), D(·), and N(·) represent the filtering functions of the high-pass filter, low-pass filter, and correction network, respectively.

[0021] Preferably, the error term loop and damping term loop of the AAC controller are designed with amplitude limiting, specifically as follows:

[0022] Based on the control accuracy requirements of flight missions, mathematical simulations are performed under normal operating conditions to obtain the angular rate deviation Δω and the error term e. r Launch vehicle attitude angle and damping term y s The signal's changing envelope range; simultaneously, combining the rocket's elastic characteristics with the onboard computer's sampling frequency, makes... and e r The amplitude limit is greater than the acceptable attitude angle deviation envelope during flight, so y s The signal limiting value is equal to the envelope range of the rocket body's elastic deviation;

[0023] For Δω, the Δω signal is written as the rigid body angular rate Δω required by the system. g Elastic noise Δω in different frequency bands tx (f) The superposition form Δω=Δω g +Δω tx (f) The limiting value should be designed to cover the maximum range of variation of the above signal, so as to ensure that the input of the subsequent filter will not be aliased or damaged due to the limiting.

[0024] Preferably, the output circuit of the AAC controller is designed with a limiting effect, specifically as follows:

[0025] Using the worst-case margin principle, without an AAC controller, the system's static amplification factor a0 is adjusted until the rocket control system reaches the upper and lower boundaries of critical stability. Under this worst-case frequency domain stability requirement, the upper limit amplitude k of the output channel is determined. tmax and lower limit amplitude k tmin .

[0026] Preferably, the output rate of change of the AAC controller is limited, specifically as follows:

[0027] Define the interference signal d(ω) as:

[0028] d(ω)=A w (ω)·sin(ω·t)

[0029] Among them, A w ω is the interference amplitude, t is the frequency, and t is the time.

[0030] Considering the rigid body cutoff frequency ω of the rocket body g and first-order elastic frequency ω t The interference magnitudes of the two important frequency bands were determined through frequency domain analysis and mathematical simulation, yielding the interference amplitude A for each band. w (ω g ) and Aw (ω t The minimum of the two values ​​is selected as the reference envelope to obtain the maximum interference acceleration amplitude A that the rocket body can tolerate in different frequency bands. wf :

[0031] A wf =min(A w (ω g ),A w (ω t ))

[0032] For the AAC controller output, it is necessary to consider that its rate of change amplitude does not exceed the aforementioned disturbance level. Furthermore, considering that the first-order elastic frequency of the rocket body is greater than the rigid body cutoff frequency, the minimum envelope combination is taken to obtain the AAC controller output rate of change. Limit:

[0033]

[0034] Wherein, κ is a coefficient less than 1, which is selected according to the actual task requirements.

[0035] Preferably, when setting a trigger access mechanism for the output change rate of the AAC controller, the trigger judgment is divided into two layers:

[0036] The first layer focuses on time-based judgment. During the rocket launch phase, large attitude maneuver phase, and power-off separation phase, no AAC controller switching judgment operation is performed to avoid additional interference to the system caused by AAC controller step jumps.

[0037] The second-level judgment uses a single-step triggering method based on the rate of change, with the AAC controller output rate of change pre-set. as well as rate of change Trigger threshold The AAC controller's calculation results will only be valid if the following conditions are met:

[0038]

[0039] Only then will it output normally; otherwise, at the current moment... Set to zero;

[0040] in, They are and The absolute value of , && represents logical AND.

[0041] Preferably, for a single-input-output AAC controller framework, there is only one input and one output, with the input being the error term e. r .

[0042] Secondly, a terminal device is provided, comprising:

[0043] Memory, used to store at least one instruction executed by a processor;

[0044] The processor is used to execute instructions stored in memory to implement the safety protection design method for the adaptive augmentation controller of the launch vehicle as described above.

[0045] Thirdly, a computer-readable storage medium is provided for storing computer instructions that, when executed on a computer, cause the computer to perform the safety protection design method for the adaptive augmentation controller of a launch vehicle as described above.

[0046] Compared with the prior art, the present invention has the following advantages:

[0047] (1) The AAC controller structure of the present invention is simpler, which is of great help to subsequent parameter design and stability evaluation;

[0048] (2) After each path of the present invention is designed for safety, it ensures that the path calculation is smooth and correct, and there will be no problems such as calculation singularity or memory overflow, and will not cause the controlled object to shake violently or cause additional interference to the controlled object.

[0049] (3) After the addition of the rate of change triggering mechanism, this invention ensures that the AAC controller does not intervene too much in the control when the controlled object is flying stably, but can respond quickly when necessary to achieve the effect of improving adaptability, which is beneficial and harmless. Attached Figure Description

[0050] Figure 1 This is a system composition block diagram of the present invention;

[0051] Figure 2 This is a diagram showing the dimensions of the lunar surface sand table screen and a lunar surface simulation diagram of the present invention;

[0052] Figure 3 This is a diagram of the three-dimensional translational motion device of the present invention. Detailed Implementation

[0053] This invention addresses the safety and reliability requirements of existing adaptive augmentation controllers applied to launch vehicles by providing a safety protection design method for an adaptive augmentation control (AAC) controller for launch vehicles. The method adjusts the structure of the AAC controller and implements protection designs for each loop.

[0054] To achieve the above objectives, the technical solution adopted by the present invention, a safety protection design method for an adaptive augmentation controller of a launch vehicle, is as follows:

[0055] Based on the characteristics of launch vehicle flight missions, to ensure that the AAC controller does not exhibit singular outputs or cause additional interference to the rocket body during flight, a safety protection design for the AAC controller is implemented. This specifically includes modifying the AAC controller to a single-input-output structure, adding limiting parameters to the input and output loops, adding limiting parameters to the AAC controller output value and rate of change, and introducing an AAC controller trigger switch mechanism. Specifically:

[0056] 1) First, the AAC controller path was adjusted and improved. The AAC algorithm access position was modified, and a correction network was added to the error term loop to simplify the control structure and construct a single-input-single-output structure;

[0057] 2) Based on the single-input-single-output structure, the three sub-modules of the AAC controller are integrated, and the limiting and protection designs are carried out for the integrated input path respectively;

[0058] 3) Based on the interference sensitivity analysis of the controlled object and the frequency domain margin index requirements under the worst operating condition, the maximum acceptable interference acceleration value is obtained by the sine derivative method, and the output limit value and output rate of change limit value of the AAC controller are set accordingly.

[0059] 4) Finally, in order to avoid unnecessary high-frequency jitter in the AAC controller output and to meet actual flight requirements, a trigger access mechanism based on the AAC controller output change rate is proposed for the output path.

[0060] Referring to the accompanying drawings, the present invention proposes a safety protection design method for an adaptive augmentation control (AAC) for launch vehicles, and the specific implementation steps are as follows:

[0061] 1) Based on the characteristics of the launch vehicle flight mission, in order to ensure that the AAC controller does not produce strange outputs or cause additional interference to the rocket body during flight, a safety protection design is carried out for the AAC controller. The specific design parameters include the input and output limiting of each loop, the limiting of the AAC controller output value and the rate of change of output, and the triggering switch mechanism of the AAC controller.

[0062] 2) First, the mathematical formula of the Adaptive Augmentation Control (AAC) controller is analyzed and adjusted. The expression for the AAC controller output loop signal is:

[0063]

[0064] k t =k a +k0 (2)

[0065] Where, kt To adapt the final output coefficients, k a k is the integral part of the output coefficients, and k0 is the constant part of the output coefficients. For k a The derivative of k tmax e represents the upper limit of the output coefficient amplitude. r The error term represents the deviation value of the reference model; y s is the damping term, representing the filter value of the spectral damper. 'a' is the error term weight, 'c' is the damping term weight, and 'β' is the regression term weight. In the expression for the output loop, e r and y s These are the low-frequency and high-frequency interference signal values, respectively, calculated from the error term loop and the damping term loop. The formula for the error term is:

[0066]

[0067] The damping term formula is:

[0068] y s =D(G(y3)) 2 (4)

[0069]

[0070] Where a0 and a1 are both constant coefficients, Δω represents the launch vehicle attitude angle and angular rate deviation, respectively. G(·), D(·), and N(·) represent the filtering functions of the high-pass filter, low-pass filter, and correction network, respectively. Observing the above equation, it can be seen that the inputs of the error term loop and the damping term loop are different, increasing the environment of the correction network. To simplify the system, the formula for the error term loop is defined as:

[0071]

[0072] The obtained system block diagram is shown below. Figure 1 With the above improvements, a single-input-output AAC controller framework can be obtained, thereby simplifying subsequent system design.

[0073] 3) Based on the single-input-output AAC controller framework, it can be seen that the AAC controller only has one input. Therefore, the error term loop, damping term loop and output loop of the AAC controller can be integrated for parameter design.

[0074] As can be seen from the formula, the input to the AAC control system is e. rThis signal directly affects the error loop. Considering that angular rate signals typically exhibit numerous glitches and high-frequency jitter interference during actual flight, this interference may occupy channel space in the low-frequency band when the system is in a limited-amplitude state. Therefore, for Δω and e... r The signals are individually limited. Conversely, in the damping phase loop, considering the priority of identifying high-frequency interference, it is necessary to... and y s The signals are individually amplitude-limited. Specifically, based on the control accuracy requirements of the flight mission, mathematical simulations are performed under normal operating conditions to obtain Δω and e. r , and y s The range of signal variation envelope. Simultaneously, combining the rocket's elastic characteristics with the onboard computer's sampling frequency, ... and e r The amplitude limit is greater than the acceptable attitude angle deviation envelope during flight, y s The signal limiting value is equal to the envelope range of the rocket body's elastic deviation. For Δω, the influence of the elastic guideway entering the control closed loop via the sensor needs to be considered. The Δω signal can be written as the rigid body angular velocity Δω required by the system. g Elastic noise Δω in different frequency bands tx (f) The superposition form Δω=Δω g +Δω tx (f) The limiting value should be designed to cover the maximum range of variation of the above signal, so as to ensure that the input of the subsequent filter will not be aliased or damaged due to the limiting.

[0075] Finally, in the output loop, using the worst-case margin principle, the system's static amplification factor a0 is adjusted until the rocket control system reaches the upper and lower boundaries of critical stability without an AAC controller. Under this worst-case frequency domain stability requirement, the upper limit amplitude k of the output channel is determined. tmax and lower limit amplitude k tmin A schematic diagram illustrating the upper and lower limits of the AAC controller obtained from the translation margin diagram is shown below. Figure 2 .

[0076] 4) Based on the single-input-output AAC controller framework, the system has only one output k. t Traditional methods typically only limit this value. In this invention, addressing the launch vehicle's sensitivity to angular velocities affected by different frequencies of interference, an innovative approach is proposed to limit the range of k... t Based on the amplitude limit, the rate of change of AAC output. Amplitude limiting is applied. Based on frequency margin analysis and time-domain simulation analysis, the anti-interference capability of the rocket body in different frequency bands is pre-assessed, given the maximum interference acceleration amplitude A that the rocket body can accept in different frequency bands. wf .

[0077] The mathematical expression for the interference signal d(ω) is:

[0078] d(ω)=A w (ω)·sin(ω·t) (7)

[0079] Among them, A w Let d(ω) be the interference amplitude, ω be the frequency, and t be the time. It can be seen that the interference signal d(ω) is a function of frequency. For launch vehicles, the rigid body cutoff frequency ω is generally of concern. g and first-order elastic frequency ω t The interference magnitudes of two important frequency bands. Through frequency domain analysis and mathematical simulation, the interference amplitude A of the two frequency bands mentioned above can be obtained. w (ω g ) and A w (ω t The minimum of the two is selected as the reference envelope, denoted as:

[0080] A wf =min(A w (ω g ),A w (ω t (8)

[0081] For the AAC controller output, it is necessary to consider that its rate of change amplitude cannot exceed the above-mentioned disturbance level. Furthermore, considering that the first-order elastic frequency of the rocket body is greater than the rigid body cutoff frequency, the minimum envelope combination is taken to obtain the AAC controller output rate of change. Limit:

[0082]

[0083] Wherein, κ is a coefficient less than 1, which is selected according to the actual task requirements.

[0084] 5), Formula (9) has already designed the output path of the single-input-output AAC controller framework with amplitude limiting to ensure that the output signal does not contain too many high-frequency characteristics. This method can suppress the interference of high-frequency disturbances with large amplitudes on low-frequency angular rate signals. However, in order to optimize the interference to the system when the amplitude of the high-frequency interference signal is small, a trigger access mechanism based on the output change rate of the AAC controller needs to be proposed. The trigger judgment is divided into two layers. The first layer is based on time judgment. During the rocket takeoff, large attitude maneuver, and power-off separation periods, the AAC controller switching judgment operation is not performed to avoid the AAC controller step jump causing additional interference to the system. The second layer of judgment adopts the single-step triggering method of change rate, and the AAC controller output change rate is preset. as well as rate of change Trigger threshold In actual flight, the AAC controller's calculations will only be valid if the following conditions are met:

[0085]

[0086] in, They are and The absolute value of , && represents AND logic, meaning that only when both of the above conditions are satisfied. Only then will it output normally; otherwise, at the current moment... Set to zero. See the flowchart for the trigger judgment process. Figure 3 .

[0087] Secondly, a terminal device is provided, comprising:

[0088] Memory, used to store at least one instruction executed by a processor;

[0089] The processor is used to execute instructions stored in memory to implement the safety protection design method for the adaptive augmentation controller of the launch vehicle as described above.

[0090] Thirdly, a computer-readable storage medium is provided for storing computer instructions that, when executed on a computer, cause the computer to perform the safety protection design method for the adaptive augmentation controller of a launch vehicle as described above.

[0091] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A safety protection design method for an adaptive augmentation controller of a launch vehicle, characterized in that... include: Adjusting the error term of the adaptive augmentation controller yields a single-input-output adaptive augmentation controller, denoted as an AAC controller. For the error term loop and damping term loop of a single-input-output AAC controller, the parameter angular rate deviation Δω and error term e are... r Launch vehicle attitude angle and damping term y s Signal amplitude limiting design; Limit the output channel of the output circuit and limit the output rate of change of the AAC controller; Set a trigger access mechanism for the output change rate of a single-input-output AAC controller; When setting a trigger access mechanism for the output change rate of the AAC controller, the trigger judgment is divided into two layers: The first layer focuses on time-based judgment. During the rocket launch phase, large attitude maneuver phase, and power-off separation phase, no AAC controller switching judgment operation is performed to avoid additional interference to the system caused by AAC controller step jumps. The second-level judgment uses a single-step triggering method based on the rate of change, with the AAC controller output rate of change pre-set. as well as rate of change Trigger threshold The AAC controller's calculation results will only be valid if the following conditions are met: Only then will it output normally; otherwise, at the current moment... Set to zero; in, They are and The absolute value of , && represents logical AND.

2. The safety protection design method for an adaptive augmentation controller of a launch vehicle according to claim 1, characterized in that: A single-input-output AAC controller, specifically: The expression for the AAC controller output circuit signal is: k t =k a +k0 Where, k t To adapt the final output coefficients, k a k is the integral part of the output coefficients, and k0 is the constant part of the output coefficients; For k a The derivative of k tmax e represents the upper limit of the output coefficient amplitude. r The error term represents the deviation value of the reference model; y s , where is the damping term, representing the filter value of the spectral damper; 'a' is the weight of the error term, 'c' is the weight of the damping term, and 'β' is the weight of the regression term. The formula for the damping term is: y s =D(G(y3) 2 ) The formula for defining the error term is: Where a0 and a1 are both constant coefficients, Δω represents the launch vehicle attitude angle and angular rate deviation, respectively, and G(·), D(·), and N(·) represent the filtering functions of the high-pass filter, low-pass filter, and correction network, respectively.

3. The safety protection design method for an adaptive augmentation controller of a launch vehicle according to claim 1, characterized in that: The error term loop and damping term loop of the AAC controller are designed with limiting, specifically as follows: Based on the control accuracy requirements of flight missions, mathematical simulations are performed under normal operating conditions to obtain the angular rate deviation Δω and the error term e. r Launch vehicle attitude angle and damping term y s The signal's changing envelope range; simultaneously, combining the rocket's elastic characteristics with the onboard computer's sampling frequency, makes... and e r The amplitude limit is greater than the acceptable attitude angle deviation envelope during flight, so y s The signal limiting value is equal to the envelope range of the rocket body's elastic deviation; For Δω, the Δω signal is written as the rigid body angular rate Δω required by the system. g Elastic noise Δω in different frequency bands tx (f) The superposition form Δω=Δω g +Δω tx (f) The limiting value should be designed to cover the maximum range of variation of the above signal, so as to ensure that the input of the subsequent filter will not be aliased or damaged due to the limiting.

4. The safety protection design method for an adaptive augmentation controller of a launch vehicle according to claim 1, characterized in that: The output circuit of the AAC controller is designed with limiting, specifically as follows: Using the worst-case margin principle, without an AAC controller, the system's static amplification factor a0 is adjusted until the rocket control system reaches the upper and lower boundaries of critical stability. Under this worst-case frequency domain stability requirement, the upper limit amplitude k of the output channel is determined. tmax and lower limit amplitude k tmin .

5. The safety protection design method for an adaptive augmentation controller of a launch vehicle according to claim 1, characterized in that: The output rate of change of the AAC controller is limited, specifically as follows: Define the interference signal d(ω) as: d(ω)=A w (ω)·sin(ω·t) Among them, A w ω is the interference amplitude, t is the frequency, and t is the time. Considering the rigid body cutoff frequency ω of the rocket body g and first-order elastic frequency ω t The interference magnitudes of the two important frequency bands were determined through frequency domain analysis and mathematical simulation, yielding the interference amplitude A for each band. w (ω g ) and A w (ω t The minimum of the two values ​​is selected as the reference envelope to obtain the maximum interference acceleration amplitude A that the rocket body can tolerate in different frequency bands. wf : A wf =min(A w (oh g ),A w (oh t )) For the AAC controller output, it is necessary to consider that its rate of change amplitude does not exceed the aforementioned disturbance level. Furthermore, considering that the first-order elastic frequency of the rocket body is greater than the rigid body cutoff frequency, the minimum envelope combination is taken to obtain the AAC controller output rate of change. Limit: Wherein, κ is a coefficient less than 1, which is selected according to the actual task requirements.

6. The safety protection design method for an adaptive augmentation controller of a launch vehicle according to claim 1, characterized in that: For a single-input-output AAC controller framework, there is only one input and one output, with the input being the error term e. r .

7. A terminal device, characterized in that, include: Memory, used to store at least one instruction executed by a processor; A processor for executing instructions stored in memory to implement the method as described in any one of claims 1-6.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1-6.

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