An adaptive design method for angular velocity limiting of air-breathing hypersonic vehicles
By introducing the correspondence between overload instructions and angle of attack instructions in air-breathing hypersonic aircraft, and combining the Mach number, dynamic pressure and mass characteristics, the variation range of the angle of attack instruction is calculated, which solves the problem that traditional controllers cannot limit the rate of change of angular velocity, realizes adaptive and precise constraint of angular velocity, and ensures the stability of the aircraft and the normal operation of the engine.
Patent Information
- Application Number
- CN202211601422.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-12-13
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2042-12-13
AI Technical Summary
Traditional controllers cannot effectively limit the rate of change of angular velocity during the flight of air-breathing hypersonic aircraft, resulting in excessively rapid attitude changes and affecting the normal operation of the engine.
By introducing the correspondence between the overload command and the angle of attack command, the angular velocity change is converted into the angular velocity change into the angular velocity change into the angular velocity limit adaptive design method, combined with the Mach number Ma, combined with the Mach number, dynamic pressure, reference area and mass characteristics, the allowable variation range of the angle of attack command is calculated, and the adaptive precise constraint on the angular velocity is achieved through the correspondence between overload and angle of attack.
It realizes adaptive and precise constraints on angular velocity changes, ensuring the normal operation of the engine and the stable flight of the aircraft. The structure is universal and suitable for the design of guidance and control systems for air-breathing hypersonic aircraft.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of hypersonic aircraft guidance and control systems, and specifically relates to a method for adaptively designing angular velocity limits for air-breathing hypersonic aircraft. This method is generally applicable to the design of guidance and control systems for air-breathing hypersonic aircraft that require a certain range of angular velocity variation. Background Art
[0002] Air-breathing hypersonic vehicles have strict restrictions on attitude changes during engine ignition and operation. Control systems must precisely control the vehicle's attitude throughout flight. Traditional controllers only limit the maximum command value, indirectly limiting the maximum angle of attack during flight, but fail to constrain the amplitude of angular velocity during attitude changes. When used in air-breathing hypersonic vehicles, traditional controllers can cause excessively rapid attitude changes, potentially impacting engine operation and leading to flight anomalies. Summary of the Invention
[0003] (1) Technical issues to be resolved
[0004] The technical problem to be solved by the present invention is: in order to solve the problem that traditional controllers cannot effectively limit the rate of change of angular velocity during the flight of air-breathing hypersonic aircraft, it is necessary to improve the design method of aircraft controllers and how to provide an adaptive design method for angular velocity limiting of air-breathing hypersonic aircraft.
[0005] (2) Technical solution
[0006] In order to solve the above technical problems, the present invention provides an angular velocity limiting adaptive design method for an air-breathing hypersonic aircraft, the method comprising the following steps:
[0007] Step 1: Overload instruction generation;
[0008] Step 2: Calculate the normal force coefficient corresponding to the overload instruction;
[0009] Step 3: Calculate the angle of attack command;
[0010] Step 4: adaptive limiting of angle of attack command;
[0011] Step 5: Calculate the overload instruction after limiting.
[0012] Wherein, in said step 1, an overload instruction is generated;
[0013] H c (kT), H(kT) represent the current altitude given by the altitude command and the inertial navigation, kT represents the current time of the missile-borne computer, and T represents the calculation cycle of the missile-borne computer. c(kT),H(kT) is simplified to H c (k), H(k); calculate the deviation ΔH(k) between the altitude instruction and the actual altitude;
[0014] ΔH(k)=H c (k)-H(k)
[0015] According to the deviation between the altitude instruction and the actual altitude, the hypersonic aircraft overload instruction n is generated. yc1 (k). ;
[0016]
[0017] in, K is the differential value of the deviation between the altitude instruction and the actual altitude, p is the proportional term control parameter, K d is the differential term control parameter.
[0018] Wherein, in said step 2, the normal force coefficient corresponding to the overload instruction is calculated;
[0019] Overload instruction n yc1 (k) is converted into the normal force coefficient, and the conversion relationship is as follows:
[0020]
[0021] Among them: CN c (k) is the normal force coefficient corresponding to the overload command, q(k) is the dynamic pressure, S is the reference area of the aircraft, and m is the mass of the aircraft.
[0022] Wherein, in said step 3, the angle of attack instruction is calculated;
[0023] The aerodynamic data of hypersonic aircraft includes the normal force coefficients at different angles of attack α and different Mach numbers Ma. By combining the normal force coefficient command corresponding to the overload command with the current flight Mach number, the angle of attack command α corresponding to the normal force coefficient command can be interpolated from the aerodynamic data. c1 (k);
[0024] α c1 (k)=interp(CN,Ma(k),CN c (k))
[0025] Where: interp is the interpolation function, and its calculation formula description is omitted. c (k) is the normal force coefficient corresponding to the overload command, q(k) is the dynamic pressure, S is the reference area of the aircraft, and m is the mass of the aircraft.
[0026] Wherein, in said step 4, the angle of attack instruction is adaptively limited;
[0027] Compare the obtained angle of attack command with the angle of attack command of the previous cycle to obtain the angle of attack command change dα c1 (k);
[0028] dα c1 (k) = α c1 (k)-α c (k-1)
[0029] The angular velocity limit is regarded as the rate limit of the angle of attack change. Multiplying the angular velocity limit by the calculation cycle of the missile-borne computer can obtain the maximum change of the angle of attack in the next cycle, which is equal to the angle of attack command change dα. c1 (k) Compare and select the smaller amount as the change of the angle of attack in the next cycle, and superimpose it with the angle of attack command of the previous cycle to achieve adaptive limitation of the angle of attack command;
[0030] α c (k) = α c (k-1)+min(dα c1 (k),dwz(k)*T),
[0031] Where: α c (k-1) is the attack angle command for one cycle, and dwz(k) is the angular velocity limit value.
[0032] Wherein, in said step 5, the overload instruction after limiting is calculated;
[0033] The control quantity of the control system is overload. The angle of attack needs to be converted into overload. By controlling the overload, the angular velocity can be indirectly controlled. The conversion relationship is as follows:
[0034]
[0035] Among them, the method generates an overload instruction from the altitude deviation, and by introducing the corresponding relationship between the overload instruction and the angle of attack instruction, the angular velocity limit is converted into the angle of attack instruction limit, and then into the overload instruction limit, thereby realizing precise adaptive limiting of the real-time overload of the air-breathing hypersonic aircraft, thereby effectively limiting the range of angular velocity variation.
[0036] The method converts the angular velocity limit into an angle of attack command limit, and then into an overload command limit, thereby realizing adaptive angular velocity limit.
[0037] The method is used to solve the problem that traditional controllers cannot effectively limit the rate of change of angular velocity during the flight of air-breathing hypersonic aircraft.
[0038] Among them, the method introduces angular velocity limiting into overload instruction limiting; first, the overload instruction is generated by using the altitude deviation, and then the overload instruction is converted into an angle of attack instruction in combination with Mach, the normal force coefficient of the entire missile, dynamic pressure, reference area, and mass characteristics. According to the expected angular velocity change range, the allowable change range of the angle of attack instruction is calculated, and the angle of attack instruction is limited. Finally, through the correspondence between overload and angle of attack, the limited angle of attack instruction is converted into an overload instruction and introduced into the controller, thereby realizing adaptive and precise constraints on angular velocity changes during flight.
[0039] (3) Beneficial effects
[0040] To address the existing technical issues, the present invention introduces angular velocity limiting into the overload command limiting. First, an overload command is generated using altitude deviation. The overload command is then converted into an angle of attack command by combining Mach, the normal force coefficient of the entire missile, dynamic pressure, reference area, and mass characteristics. Based on the desired angular velocity variation range, the allowable range of the angle of attack command is calculated and the angle of attack command is limited. Finally, based on the correspondence between overload and angle of attack, the limited angle of attack command is converted into an overload command and introduced into the controller, achieving adaptive and precise constraints on angular velocity variations during flight. This controller design method has a versatile structure and strong engineering practicality.
[0041] Compared to existing technologies, the method presented in this paper has been applied to the development of a domestic air-breathing hypersonic aircraft project. The designed angular velocity adaptive limiter ensures that the angular velocity of the hypersonic aircraft remains within a given angular velocity constraint during engine operation, while also achieving highly stable and rapid tracking. This method has broad prospects for military applications. DETAILED DESCRIPTION
[0042] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below with reference to the embodiments.
[0043] In order to solve the above technical problems, the present invention provides an adaptive design method for angular velocity limiting of an air-breathing hypersonic aircraft. In order to effectively and accurately achieve angular velocity limitation indirectly by limiting overload, a new correction strategy is introduced in the design of the adaptive overload limiter.
[0044] The method comprises the following steps:
[0045] Step 1: Overload instruction generation;
[0046] Step 2: Calculate the normal force coefficient corresponding to the overload instruction;
[0047] Step 3: Calculate the angle of attack command;
[0048] Step 4: adaptive limiting of angle of attack command;
[0049] Step 5: Calculate the overload instruction after limiting.
[0050] Wherein, in said step 1, an overload instruction is generated;
[0051] H c (kT), H(kT) represent the current altitude given by the altitude command and the inertial navigation, kT represents the current time of the missile-borne computer, and T represents the calculation cycle of the missile-borne computer. c (kT),H(kT) is simplified to H c (k), H(k); calculate the deviation ΔH(k) between the altitude instruction and the actual altitude;
[0052] ΔH(k)=H c (k)-H(k)
[0053] According to the deviation between the altitude instruction and the actual altitude, the hypersonic aircraft overload instruction n is generated. yc1 (k). ;
[0054]
[0055] in, K is the differential value of the deviation between the altitude instruction and the actual altitude, p is the proportional term control parameter, K d is the differential term control parameter.
[0056] Wherein, in said step 2, the normal force coefficient corresponding to the overload instruction is calculated;
[0057] Overload instruction n yc1 (k) is converted into the normal force coefficient, and the conversion relationship is as follows:
[0058]
[0059] Among them: CN c (k) is the normal force coefficient corresponding to the overload command, q(k) is the dynamic pressure, S is the reference area of the aircraft, and m is the mass of the aircraft.
[0060] Wherein, in said step 3, the angle of attack instruction is calculated;
[0061] The aerodynamic data of hypersonic aircraft includes the normal force coefficients at different angles of attack α and different Mach numbers Ma. By combining the normal force coefficient command corresponding to the overload command with the current flight Mach number, the angle of attack command α corresponding to the normal force coefficient command can be interpolated from the aerodynamic data. c1 (k);
[0062] α c1 (k)=interp(CN,Ma(k),CNc (k))
[0063] Where: interp is the interpolation function, and its calculation formula description is omitted. c (k) is the normal force coefficient corresponding to the overload command, q(k) is the dynamic pressure, S is the reference area of the aircraft, and m is the mass of the aircraft.
[0064] Wherein, in said step 4, the angle of attack instruction is adaptively limited;
[0065] Compare the obtained angle of attack command with the angle of attack command of the previous cycle to obtain the angle of attack command change dα c1 (k);
[0066] dα c1 (k) = α c1 (k)-α c (k-1)
[0067] The angular velocity limit is regarded as the rate limit of the angle of attack change. Multiplying the angular velocity limit by the calculation cycle of the missile-borne computer can obtain the maximum change of the angle of attack in the next cycle, which is equal to the angle of attack command change dα. c1 (k) Compare and select the smaller amount as the change of the angle of attack in the next cycle, and superimpose it with the angle of attack command of the previous cycle to achieve adaptive limitation of the angle of attack command;
[0068] α c (k) = α c (k-1)+min(dα c1 (k),dwz(k)*T),
[0069] Where: α c (k-1) is the attack angle command for one cycle, and dwz(k) is the angular velocity limit value.
[0070] Wherein, in said step 5, the overload instruction after limiting is calculated;
[0071] The control quantity of the control system is overload. The angle of attack needs to be converted into overload. By controlling the overload, the angular velocity can be indirectly controlled. The conversion relationship is as follows:
[0072]
[0073] Among them, the method generates an overload instruction from the altitude deviation, and by introducing the corresponding relationship between the overload instruction and the angle of attack instruction, the angular velocity limit is converted into the angle of attack instruction limit, and then into the overload instruction limit, thereby realizing precise adaptive limiting of the real-time overload of the air-breathing hypersonic aircraft, thereby effectively limiting the range of angular velocity variation.
[0074] The method converts the angular velocity limit into an angle of attack command limit, and then into an overload command limit, thereby realizing adaptive angular velocity limit.
[0075] The method is used to solve the problem that traditional controllers cannot effectively limit the rate of change of angular velocity during the flight of air-breathing hypersonic aircraft.
[0076] Among them, the method introduces angular velocity limiting into overload instruction limiting; first, the overload instruction is generated by using the altitude deviation, and then the overload instruction is converted into an angle of attack instruction in combination with Mach, the normal force coefficient of the entire missile, dynamic pressure, reference area, and mass characteristics. According to the expected angular velocity change range, the allowable change range of the angle of attack instruction is calculated, and the angle of attack instruction is limited. Finally, through the correspondence between overload and angle of attack, the limited angle of attack instruction is converted into an overload instruction and introduced into the controller, thereby realizing adaptive and precise constraints on angular velocity changes during flight.
[0077] Example 1
[0078] The present invention is further described with reference to a hypersonic aircraft system calculation example. The hypersonic aircraft flies with an initial ballistic inclination of 9.5°, an operating altitude of 18,700m, and an operating speed of 1,400m / s. It needs to climb to a cruising altitude for altitude-holding cruise. The aircraft performs ignition preparation for the first 2 seconds, and the engine ignites after 2 seconds. The angular velocity changes within the first 5 seconds of engine operation are ≤0.5° / s, and the angular velocity changes within 5 seconds are ≤1.5° / s.
[0079] Step 1: Overload instruction generation
[0080] The calculation cycle T of the missile-borne computer is 4ms. c is the one-dimensional interpolation table of time; the proportional term control parameter K p Selected as 0.1, the differential term control parameter K d Selected as 0.6. Hypersonic aircraft overload command n yc1 (k) is:
[0081]
[0082] Step 2: Calculate the normal force coefficient corresponding to the overload instruction
[0083] Overload instruction n yc1 (k) is converted into the normal force coefficient, and the conversion relationship is as follows:
[0084]
[0085] q is the real-time dynamic pressure, and the rocket mass m is 500 kg.
[0086] Step 3: Calculate the angle of attack command
[0087] The aerodynamic data of the aircraft are divided into different angles of attack α=[-5 0 5 10] and different Mach numbers Ma c =[4 5 6] The normal force coefficient is as follows:
[0088]
[0089] The normal force coefficient is calculated using aerodynamic data in Ma c =[4 5 6] corresponding angle of attack α c 4, α c 5, α c 6.
[0090] α c 4=interp1(CN1,α,CN c )
[0091] α c 5=interp1(CN2,α,CN c )
[0092] α c 6=interp1(CN3,α,CN c )
[0093] Among them, CN1, CN2, and CN3 represent the first row elements, second row elements, and third row elements of the normal force coefficient CN, respectively.
[0094] Then interpolate the angle of attack command α based on the current flight Mach number c1 (k)
[0095] α c1 (k)=interp1([α c 4α c 5α c 6],[4 5 6],Ma)
[0096] Step 4: Adaptive limiting of angle of attack command
[0097] Since the angular velocity change is ≤0.5° / s in the first 5s of the engine operation and ≤1.5° / s after 5s, the angular velocity limit is a one-dimensional table of time, that is,
[0098] dwz(k)=interp1([0 5 5.1 1000],[0.5 0.5 1.5 1.5],t)
[0099] Compare the obtained angle of attack command with the angle of attack command of the previous cycle to obtain the angle of attack command change dα c1 (k).
[0100] dαc1 (k) = α c1 (k)-α c (k-1)
[0101] The adaptive limit of the angle of attack command is:
[0102] α c (k) = α c (k-1)+min(dα c1 (k),dwz(k)*T),
[0103] Step 5: Calculate the overload instruction after limiting
[0104] The control quantity of the control system is overload. The angle of attack needs to be converted into overload. By controlling the overload, the angular velocity can be indirectly controlled. The conversion relationship is as follows:
[0105]
[0106] In the simulation, the adaptive angular velocity limiting design method and controller of the present invention were used during the aircraft's climb and cruise flight, and their performance was compared. The simulation results show that the aircraft in this example can stably track altitude commands and achieve cruise control during flight. The controller of the present invention can accurately and adaptively correct the angular velocity in real time, keeping it within a safe range, ensuring the normal operation of the engine and achieving stable flight.
[0107] The present invention belongs to the technical field of hypersonic aircraft guidance and control systems, and specifically relates to a method for designing an adaptive angular velocity limiter for an air-breathing hypersonic aircraft. By introducing a corresponding relationship between an overload instruction and an angle of attack instruction, the angular velocity limiter is converted into an angle of attack instruction limiter, and then into an overload instruction limiter, thereby effectively and reliably limiting the angular velocity variation range indirectly by limiting the overload instruction. Without changing the controller structure, the adaptive angular velocity limiter is achieved by changing the limiting method, effectively ensuring the angular velocity variation requirement during the flight of the air-breathing hypersonic aircraft.
[0108] This invention addresses the strict constraints on angular velocity variations in air-breathing hypersonic aircraft during flight. First, an altitude deviation is used to generate an overload command. Then, based on the correspondence between overload and angle of attack, the overload command is converted into an angle of attack command. Based on the desired range of angular velocity variation, the allowable range of the angle of attack command is calculated, and the angle of attack command is clipped. Finally, based on the correspondence between overload and angle of attack, the clipped angle of attack command is again converted into an overload command and introduced into the controller, thus constraining angular velocity variations during flight. This adaptive angular velocity clipping design method has a versatile structure and strong engineering practicality. It is expected to be widely applied in the design of guidance and control systems for various air-breathing hypersonic aircraft requiring angular velocity clipping in the future.
[0109] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A method for adaptively designing angular velocity limiting for an air-breathing hypersonic vehicle, characterized in that: The method comprises the following steps: Step 1: Overload instruction generation; Step 2: Calculate the normal force coefficient corresponding to the overload instruction; Step 3: Calculate the angle of attack command; Step 4: adaptive limiting of angle of attack command; Step 5: Calculate the overload instruction after limiting; Wherein, in said step 3, the angle of attack instruction is calculated; The aerodynamic data of hypersonic aircraft includes the normal force coefficients at different angles of attack α and different Mach numbers Ma. By combining the normal force coefficient command corresponding to the overload command with the current flight Mach number, the angle of attack command α corresponding to the normal force coefficient command can be interpolated from the aerodynamic data. c1 (k); a c1 (k)=interp(CN,Ma(k),CN c (k)) Where: interp is the interpolation function, and its calculation formula description is omitted; CN c (k) is the normal force coefficient corresponding to the overload instruction; Wherein, in said step 4, the angle of attack instruction is adaptively limited; Compare the obtained angle of attack command with the angle of attack command of the previous cycle to obtain the angle of attack command change dα c1 (k); dα c1 (k)=a c1 (k)-a c (k-1) The angular velocity limit is regarded as the rate limit of the angle of attack change. Multiplying the angular velocity limit by the calculation cycle of the missile-borne computer can obtain the maximum change of the angle of attack in the next cycle, which is equal to the angle of attack command change dα. c1 (k) Compare and select the smaller amount as the change of the angle of attack in the next cycle, and superimpose it with the angle of attack command of the previous cycle to achieve adaptive limitation of the angle of attack command; a c (k)=a c (k-1)+min(dα c1 (k),dwz(k)*T), Where: α c (k-1) is the angle of attack command of the previous cycle, dwz(k) is the angular velocity limit value, and T represents the calculation cycle of the onboard computer.
2. The method for adaptively designing angular velocity limiting of an air-breathing hypersonic vehicle according to claim 1, wherein: In the step 1, an overload instruction is generated; H c (kT), H(kT) represent the current altitude given by the altitude command and the inertial navigation, respectively; kT represents the current time of the onboard computer; T represents the calculation cycle of the onboard computer; for the sake of convenience, H c (kT),H(kT) is simplified to H c (k), H(k); calculate the deviation ΔH(k) between the altitude instruction and the actual altitude; ΔH(k)=H c (k)-H(k) According to the deviation between the altitude instruction and the actual altitude, the hypersonic aircraft overload instruction n is generated. yc1 (k); in, K is the differential value of the deviation between the altitude instruction and the actual altitude, p is the proportional term control parameter, K d is the differential term control parameter.
3. The method for adaptively designing angular velocity limiting of an air-breathing hypersonic vehicle according to claim 2, wherein: In step 2, the normal force coefficient corresponding to the overload instruction is calculated; Overload instruction n yc1 (k) is converted into the normal force coefficient, and the conversion relationship is as follows: Among them: CN c (k) is the normal force coefficient corresponding to the overload command, q(k) is the dynamic pressure, S is the reference area of the aircraft, and m is the mass of the aircraft.
4. The method for adaptively designing angular velocity limiting of an air-breathing hypersonic vehicle according to claim 3, wherein: In the step 5, the overload instruction after limiting is calculated; The control quantity of the control system is overload. The angle of attack needs to be converted into overload. By controlling the overload, the angular velocity can be indirectly controlled. The conversion relationship is as follows:
5. The method for adaptively designing angular velocity limiting of an air-breathing hypersonic vehicle according to claim 4, wherein: The method generates an overload instruction from an altitude deviation, and by introducing a corresponding relationship between the overload instruction and the angle of attack instruction, converts the angular velocity limit into an angle of attack instruction limit, and then into an overload instruction limit, thereby achieving precise adaptive limiting of the real-time overload of an air-breathing hypersonic aircraft, thereby effectively limiting the range of angular velocity variation.
6. The method for adaptively designing angular velocity limiting of an air-breathing hypersonic vehicle according to claim 5, wherein: The method converts the angular velocity limit into an angle of attack command limit, and then into an overload command limit, thereby realizing angular velocity adaptive limit.
7. The method for adaptively designing angular velocity limiting for an air-breathing hypersonic vehicle according to claim 5, wherein: The method introduces angular velocity limiting into overload instruction limiting. First, an overload instruction is generated using altitude deviation. Then, the overload instruction is converted into an angle of attack instruction by combining Mach, the normal force coefficient of the entire missile, dynamic pressure, reference area, and mass characteristics. Based on the expected angular velocity variation range, the allowable variation range of the angle of attack instruction is calculated, and the angle of attack instruction is limited. Finally, based on the corresponding relationship between overload and angle of attack, the limited angle of attack instruction is converted into an overload instruction and introduced into a controller, thereby realizing adaptive and precise constraint on angular velocity variation during flight.