A method for separating the control of a symmetric reentry vehicle under lateral instability conditions

Abstract

The application relates to a separation control method for a symmetric reentry vehicle under lateral instability, and belongs to the technical field of attitude control. A three-channel trimming capability equation is established; lateral control deviation parameters LCDP are calculated; according to the three-channel trimming capability equation and the lateral control deviation parameters LCDP, the controllable attack angle interval of the vehicle is determined as [alpha min , alpha max ]; when the time is, the lateral instability is controlled; according to the physical limit constraint of the pitch rudder deviation range, a target attack angle alpha cx of preset pitch rudder deviation setting attitude adjustment demand before separation is formulated, and the separation control is performed according to the target attack angle alpha cx of the attitude adjustment demand; the application forms a separation control method for a reentry vehicle under lateral instability, is used for vehicle stable separation control method demonstration for the case that the separation control is lateral instability and the control capability is insufficient, and ensures the stability of the vehicle separation control.

Description

Technical Field

[0001] This invention belongs to the field of attitude control technology and relates to a separation and take-off control method for a symmetrical reentry vehicle under lateral instability conditions. Background Technology

[0002] For symmetrical reentry vehicles, yaw stability is weak and control efficiency is low, typically occurring at high altitudes, high speeds, and low angles of attack. Under these conditions, low angle-of-attack separation and launch vehicles face typical control characteristics of insufficient lateral trim capability and lateral instability. While shape optimization can improve these characteristics, it leads to a decrease in lift-to-drag ratio, deterioration of static stability, and reduction in load ratio, among other performance issues. Therefore, considering the overall performance of the vehicle, it is necessary to research a separation and launch control method for reentry vehicles under lateral instability conditions, but this currently presents technical challenges. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a separation and launch control method for a symmetrical reentry vehicle under lateral instability conditions. This method addresses the issue of insufficient control capability due to lateral instability in separation and launch control, and is used to demonstrate a stable separation and launch control method for the vehicle, ensuring the stability of the separation and launch control.

[0004] The solution of the present invention is:

[0005] A separation and launch control method for a surface-symmetric reentry vehicle under lateral instability conditions includes:

[0006] Establish the three-channel balancing capability equation;

[0007] Calculate the lateral control deviation parameter LCDP;

[0008] Let the actual angle of attack be denoted by α. Based on the three-channel trim capability equation and the lateral control deviation parameter LCDP, the controllable lateral angle of attack range of the aircraft is determined to be [α]. min ,α max ];

[0009] when At that time, it was a lateral unstable start-up control;

[0010] Based on the physical limits of the pitch deflection range, a pre-set pitch deflection is formulated before separation.

[0011] Set the target angle of attack α for attitude adjustment requirements. cx The target angle of attack α is determined according to the attitude adjustment requirements. cx Perform separation and start-up control.

[0012] Under the aforementioned separation and takeoff control method for a symmetrical reentry vehicle under lateral instability conditions, the three-channel trim capability equation is as follows:

[0013]

[0014] In the formula, M x M y M z It is a three-channel torque;

[0015] Ma,h,α,β, δ ψ ,δ γ In order, they are Mach number, altitude, angle of attack, sideslip angle, pitch deflection, yaw deflection, and roll deflection.

[0016] In the above-mentioned separation and launch control method under lateral instability of a symmetrical reentry vehicle, the three-channel trim capability equation achieves zero resultant torque of the three channels under different flight states.

[0017] In the separation and takeoff control method for a symmetrical reentry vehicle under lateral instability conditions described above, the calculation method for the lateral control deviation parameter LCDP is as follows:

[0018]

[0019] In the formula, These are the yaw static stability parameters;

[0020] For yaw rudder effect parameters;

[0021] These are the parameters for static stability during rolling.

[0022] For roll rudder effect parameters;

[0023] The yaw moment coefficient caused by unit roll rudder deflection;

[0024] The coefficient of the rolling moment caused by unit yaw rudder deflection;

[0025] k ψ This is the feedback gain for the yaw channel sideslip angle.

[0026] In the above-mentioned separation and takeoff control method for a symmetrical reentry vehicle under lateral instability conditions, the controllable lateral angle of attack range of the vehicle is [α]. min ,α max The method for determining ] is as follows:

[0027] When α is in [α min ,α max When within the range, If there is a solution and LCDP < 0, then [α] is determined. min ,α max [This refers to the range of controllable angles of attack for the aircraft in the lateral direction.]

[0028] Separation and launch control method under lateral instability conditions of a symmetrical reentry vehicle (as described above) This is the torque applied to the pitch channel.

[0029] In the above-mentioned separation and control method for a symmetrical reentry vehicle under lateral instability conditions, the preset pitch rudder deflection... Its function is to provide initial angular acceleration, enabling the angle of attack α after separation to quickly approach the controllable angle of attack range [α]. min ,α max ].

[0030] In the aforementioned separation and takeoff control method for a symmetrical reentry vehicle under lateral instability conditions, the target angle of attack α is determined based on the attitude adjustment requirements. cx Separate control includes two modes: proportional-derivative control and angular velocity control.

[0031] In the above-mentioned separation and takeoff control method for a symmetrical reentry vehicle under lateral instability conditions, when the target angle of attack α required for attitude adjustment is... cx In [α] min ,α max Within the specified interval, proportional-derivative (PD) control is used to achieve rapid convergence and stable attitude control; the PDR control equation is as follows:

[0032]

[0033] In the formula, δ ψcx ,δ γcx The commands are pitch yaw, yaw, and roll yaw, respectively.

[0034] α,β,γ,γ cx These are the commands for angle of attack, sideslip angle, roll angle, and roll angle, respectively.

[0035] ω x ,ω y ,ω z These are roll rate, yaw rate, and pitch rate, respectively.

[0036] k pψ ,k dψ ,k pγ ,k dγ These are the proportional gain of the pitch channel, the differential gain of the pitch channel, the proportional gain of the yaw channel, the differential gain of the yaw channel, the proportional gain of the roll channel, and the differential gain of the roll channel.

[0037] In the above-mentioned separation and takeoff control method for a symmetrical reentry vehicle under lateral instability conditions, when the target angle of attack α required for attitude adjustment is... cx In [α] min ,α max Outside the specified range, angular velocity control is used to achieve velocity damping control; the angular velocity control equation is:

[0038]

[0039] In the formula, δ ψcx ,δ γcx The commands are pitch yaw, yaw, and roll yaw, respectively.

[0040] α and β are the angle of attack and sideslip angle, respectively;

[0041] ω x ,ω y ,ω z These are roll rate, yaw rate, and pitch rate, respectively.

[0042] k pψ ,k dψ ,k pγ ,k dγ These are the proportional gain of the pitch channel, the differential gain of the pitch channel, the proportional gain of the yaw channel, the differential gain of the yaw channel, the proportional gain of the roll channel, and the differential gain of the roll channel.

[0043] The advantages of this invention compared to the prior art are:

[0044] (1) The separation and launch control method for reentry vehicles under lateral instability proposed in this invention can achieve rapid and stable attitude control and optimize the overall performance of the vehicle when the vehicle is laterally unstable and the lateral trim capability is insufficient during the separation and launch control state.

[0045] (2) Based on the three-channel trim capability equation and the lateral control deviation parameter LCDP, this invention determines the controllable lateral angle of attack range of the aircraft as [α]. min ,α max This study clarifies the distinguishing indicators between lateral unstable start-up control and stable start-up control under unstable conditions.

[0046] (3) This invention will adjust the target angle of attack α required for attitude adjustment. cx The controllable lateral angle of attack range of the aircraft is [α]. min ,α maxBy comparison, it was determined that two modes of separate start-up control, including proportional-derivative control or angular velocity control, were adopted to achieve stable start-up control under different conditions. Attached Figure Description

[0047] Figure 1 This is a flowchart illustrating the separation and control process under lateral instability conditions of the present invention. Detailed Implementation

[0048] The present invention will be further described below with reference to the embodiments.

[0049] This invention provides a separation and launch control method for a symmetrical reentry vehicle under lateral instability conditions. It addresses the issue of insufficient control capability due to lateral instability during separation and launch control, and is used to demonstrate a stable separation and launch control method for the vehicle, ensuring the stability of the separation and launch control.

[0050] Separation and launch control methods for symmetrical reentry vehicles under lateral instability conditions, such as Figure 1 As shown, the specific steps include the following:

[0051] Establish the three-channel balancing capability equation; the three-channel balancing capability equation is as follows:

[0052]

[0053] In the formula, M x M y M z It is a three-channel torque;

[0054] Ma,h,α,β, δ ψ ,δ γ In order, they are Mach number, altitude, angle of attack, sideslip angle, pitch deflection, yaw deflection, and roll deflection.

[0055] The three-channel trim capability equation ensures that the resultant torque of the three channels is zero under different flight conditions.

[0056] Calculate the lateral control deviation parameter LCDP; the calculation method for the lateral control deviation parameter LCDP is as follows:

[0057]

[0058] In the formula, These are the yaw static stability parameters;

[0059] For yaw rudder effect parameters;

[0060] These are the parameters for static stability during rolling.

[0061] For roll rudder effect parameters;

[0062] The yaw moment coefficient caused by unit roll rudder deflection;

[0063] The coefficient of the rolling moment caused by unit yaw rudder deflection;

[0064] k ψ This is the feedback gain for the yaw channel sideslip angle.

[0065] Let the actual angle of attack be denoted by α. Based on the three-channel trim capability equation and the lateral control deviation parameter LCDP, the controllable lateral angle of attack range of the aircraft is determined to be [α]. min ,α max ]; The controllable lateral angle of attack range of the aircraft [α] min ,α max The method for determining ] is as follows:

[0066] When α is in [α min ,α max When within the range, If there is a solution and LCDP < 0, then [α] is determined. min ,α max [This refers to the range of controllable angles of attack for the aircraft in the lateral direction.] This is the torque applied to the pitch channel.

[0067] when At that time, it is an unstable start-up control in the lateral direction.

[0068] Based on the physical limits of the pitch deflection range, a pre-set pitch deflection is formulated before separation. Preset pitch rudder deflection Its function is to provide initial angular acceleration, enabling the angle of attack α after separation to quickly approach the controllable angle of attack range [α]. min ,α max ].

[0069] Set the target angle of attack α for attitude adjustment requirements. cx The target angle of attack α is determined according to the attitude adjustment requirements. cx Perform separation and start-up control.

[0070] Based on the target angle of attack α required for attitude adjustment cx Separate control includes two modes: proportional-derivative control and angular velocity control.

[0071] When the target angle of attack for attitude adjustment needs is α cx In [α] min ,α max Within the specified interval, proportional-derivative (PD) control is used to achieve rapid convergence and stable attitude control; the PDR control equation is as follows:

[0072]

[0073] In the formula, δ ψcx ,δ γcx The commands are pitch yaw, yaw, and roll yaw, respectively.

[0074] α,β,γ,γ cx These are the commands for angle of attack, sideslip angle, roll angle, and roll angle, respectively.

[0075] ω x ,ω y ,ω z These are roll rate, yaw rate, and pitch rate, respectively.

[0076] k pψ ,k dψ ,k pγ ,k dγ These are the proportional gain of the pitch channel, the differential gain of the pitch channel, the proportional gain of the yaw channel, the differential gain of the yaw channel, the proportional gain of the roll channel, and the differential gain of the roll channel.

[0077] When the target angle of attack for attitude adjustment needs is α cx In [α] min ,α max Outside the specified range, angular velocity control is used to achieve velocity damping control; the angular velocity control equation is:

[0078]

[0079] In the formula, δ ψcx ,δ γcx The commands are pitch yaw, yaw, and roll yaw, respectively.

[0080] α and β are the angle of attack and sideslip angle, respectively;

[0081] ω x ,ω y ,ω z These are roll rate, yaw rate, and pitch rate, respectively.

[0082] k pψ ,k dψ ,k pγ ,k dγ These are the proportional gain of the pitch channel, the differential gain of the pitch channel, the proportional gain of the yaw channel, the differential gain of the yaw channel, the proportional gain of the roll channel, and the differential gain of the roll channel.

[0083] The separation and launch control method for reentry vehicles under lateral instability proposed in this invention can achieve rapid and stable attitude control and optimize the overall performance of the vehicle when the vehicle is laterally unstable and lacks sufficient lateral trim capability during separation and launch.

[0084] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A separation and launch control method for a symmetrical reentry vehicle under lateral instability conditions, characterized in that: include: Establish the three-channel balancing capability equation; The three-channel balancing capability equation is: In the formula, It is a three-channel torque; In order, they are Mach number, altitude, angle of attack, sideslip angle, pitch deflection, yaw deflection, and roll deflection; Calculate lateral control deviation parameters ; Lateral control deviation parameters The calculation method is as follows: In the formula, These are the yaw static stability parameters; For yaw rudder effect parameters; These are the parameters for static stability during rolling. For roll rudder effect parameters; The yaw moment coefficient caused by unit roll rudder deflection; The coefficient of the rolling moment caused by unit yaw rudder deflection; For yaw channel sideslip angle feedback gain; Setting the actual angle of attack for flight This indicates that, based on the three-channel trim capability equation and the lateral control deviation parameters... Determine the controllable lateral angle of attack range of the aircraft. ; The controllable angle of attack range of the aircraft in the lateral direction The method for determining it is as follows: when exist When within range, There is a solution and Then determine This refers to the controllable lateral angle of attack range for the aircraft. when At that time, it was a lateral unstable start-up control; Based on the physical limits of the pitch deflection range, a pre-set pitch deflection is formulated before separation. ; The preset pitch rudder deflection Its function is to provide the initial angular acceleration to achieve the angle of attack after separation. Rapidly approaching the controllable angle of attack range ; Set the target angle of attack for attitude adjustment requirements. The target angle of attack according to the attitude adjustment requirements Perform separation and start-up control.

2. The separation and takeoff control method for a symmetrical reentry vehicle under lateral instability conditions according to claim 1, characterized in that: The three-channel trim capability equation ensures that the resultant torque of the three channels is zero under different flight conditions.

3. The separation and launch control method for a symmetrical reentry vehicle under lateral instability conditions according to claim 2, characterized in that: This is the torque applied to the pitch channel.

4. The separation and takeoff control method for a symmetrical reentry vehicle under lateral instability conditions according to claim 1, characterized in that: Target angle of attack based on attitude adjustment requirements Separate control includes two modes: proportional-derivative control and angular velocity control.

5. A separation and takeoff control method for a symmetrical reentry vehicle under lateral instability conditions according to claim 4, characterized in that: When the target angle of attack for attitude adjustment needs exist Within the specified interval, proportional-derivative (PD) control is used to achieve rapid attitude convergence and stable control; the PDR control equation is as follows: In the formula, The commands are pitch yaw, yaw, and roll yaw, respectively. These are the commands for angle of attack, sideslip angle, roll angle, and roll angle, respectively. These are roll rate, yaw rate, and pitch rate, respectively. These are the proportional gain of the pitch channel, the differential gain of the pitch channel, the proportional gain of the yaw channel, the differential gain of the yaw channel, the proportional gain of the roll channel, and the differential gain of the roll channel.

6. The separation and takeoff control method for a symmetrical reentry vehicle under lateral instability conditions according to claim 4, characterized in that: When the target angle of attack for attitude adjustment needs exist Outside the specified range, angular velocity control is used to achieve velocity damping control; the angular velocity control equation is: In the formula, The commands are pitch yaw, yaw, and roll yaw, respectively. These are the angle of attack and the sideslip angle, respectively. These are roll rate, yaw rate, and pitch rate, respectively. These are the proportional gain of the pitch channel, the differential gain of the pitch channel, the proportional gain of the yaw channel, the differential gain of the yaw channel, the proportional gain of the roll channel, and the differential gain of the roll channel.

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