Sideslip angle control method for rocket fairing separation in windy condition
阅读说明：本技术 一种有风时火箭整流罩分离的侧滑角控制方法 (Sideslip angle control method for rocket fairing separation in windy condition ) 是由 董佩超 梁建军 赵新强 孙永丰 朱洪亮 陈景鹏 于 2020-05-07 设计创作，主要内容包括：本发明一种有风时火箭整流罩分离的侧滑角控制方法,属飞行器姿态控制领域,尤其涉及火箭整流罩分离的姿态控制。本发明通过火箭整流罩分离前箭体z轴受到的侧向力的两种表达式,根据原始气动数据估算侧向力对侧滑角的导数,然后结合惯组测量信息,估算出火箭整流罩分离前包含风附加侧滑角信息的箭体实际侧滑角,并加以控制,实现整流罩分离前的侧滑角精确控制。采用本方法,可估算出无法直接测量的包含风侧滑角信息的箭体实际侧滑角,实现整流罩分离前的精确控制,为整流罩分离创造良好的条件。(The invention discloses a sideslip angle control method for rocket fairing separation in windy conditions, belongs to the field of aircraft attitude control, and particularly relates to attitude control for rocket fairing separation. According to the method, two expressions of the lateral force applied to the z axis of the rocket body before the rocket fairing separation are used, the derivative of the lateral force to the sideslip angle is estimated according to original aerodynamic data, then the actual sideslip angle of the rocket body containing wind-added sideslip angle information before the rocket fairing separation is estimated by combining the inertia group measurement information, and the actual sideslip angle is controlled, so that the accurate control of the sideslip angle before the fairing separation is realized. By adopting the method, the actual slip angle of the arrow body containing the wind slip angle information which cannot be directly measured can be estimated, the accurate control before the separation of the fairing is realized, and a good condition is created for the separation of the fairing.)
1. A method for controlling a sideslip angle of rocket fairing separation in windy conditions is mainly characterized by comprising the following three aspects:
the attitude of the rocket fairing before separation is controlled by a method of firstly estimating the actual sideslip angle of the rocket body containing additional sideslip angle information caused by wind and then controlling the sideslip angle.
2. The method for estimating the actual sideslip angle of the rocket body containing the additional sideslip angle information caused by wind comprises the following steps:
firstly solving the lateral force on the z axis of the rocket body:
wherein FzIs the lateral force on the Z axis of the rocket body, m is the rocket mass (no power section before the fairing is separated, constant value), and delta WzAnd T is the control period.
And then solving the lateral aerodynamic force on the z axis of the rocket body: because the engine does not work before the rocket fairing is separated and only receives aerodynamic force, the aerodynamic lateral force generated under the condition of small lateral slip angle can be expressed as
WhereinThe derivative of the lateral force to the sideslip angle is shown as β, the actual sideslip angle of the rocket body is shown as q, the dynamic pressure calculated by the rocket machine in real time is shown as q, and S is the aerodynamic reference area (constant value) of the rocket.
The derivative of the lateral force to the sideslip angle is then estimated:the rocket is estimated by adopting an approximate method, the trajectory of the rocket is stable before the fairing is separated, and the rocket is in the states of small attack angle, small sideslip and small rudder deflection,the aerodynamic data obtained by Mach number interpolation calculation can be obtained by adopting the aerodynamic data when the attack angle α is 0 degrees, the sideslip angle β is 4 degrees and the rudder deviation is 0 degrees
Wherein C isz(Ma，α0.，β4.，0The lateral force of the rocket under different Mach numbers of α -0 degrees, β -4 degrees and 0 degrees is interpolated by a pneumatic data table according to the Mach number, and Ma is the Mach number calculated by the rocket in real time.
And finally, solving the actual sideslip angle of the rocket body containing wind information: simultaneous 1)2)3) can be obtained
3. The method for separating the front control sideslip angle of the fairing comprises the following steps:
ψ＝ψ0+kβa.9.. a.ψIn order to meet the requirement of the rudder turning angle of the yaw channel,ψ0yaw channel rudder yaw angle requirement, k, calculated for traditional PD control algorithmβIn order to design the sideslip angle control coefficient, β is the actual sideslip angle of the arrow body, and the accurate control of the attitude angle, the angular speed, the sideslip angle and the like can be simultaneously realized through the cooperative optimization design of the PD control coefficient and the sideslip angle control coefficient.
Therefore, the sideslip angle control method for rocket fairing separation in windy conditions is realized.
Technical Field
The invention discloses a sideslip angle control method for rocket fairing separation in windy conditions, belongs to the field of aircraft attitude control, and particularly relates to attitude control for rocket fairing separation.
Background
The separation height of a certain commercial rocket fairing is 30-40 km, the influence of wind cannot be ignored, and if a traditional PD control algorithm is adopted in the wind, the sideslip angle at the fairing separation moment is large, so that the separation is not favorable, and therefore a sideslip angle control method is necessary to be added. However, the sideslip angle of the rocket machine before the fairing separation, which is calculated by the speed of the rocket body, does not contain additional sideslip angle information caused by wind, but the additional sideslip angle caused by the wind is unknown, and because no equipment or technical means capable of directly measuring the additional sideslip angle information of the wind exists at present, the actual sideslip angle of the rocket body is unknown, which brings certain difficulty to the accurate control of the fairing separation.
Because no equipment or technology capable of directly measuring the additional sideslip angle caused by wind exists at present, the traditional control method cannot control the actual sideslip angle of the rocket, and the method provided by the invention can effectively estimate the wind additional sideslip angle before the separation of the fairing, so that the actual sideslip angle of the rocket body containing the additional sideslip angle information caused by the wind is controlled, the accurate control before the separation of the fairing is realized, good conditions are created for the separation of the fairing, and the method is greatly improved compared with the traditional control method.
Disclosure of Invention
The invention provides a sideslip angle control method for rocket fairing separation in windy conditions.
The method mainly comprises the following steps:
(1) solving the lateral force on the z axis of the rocket body:
wherein FzIs the lateral force on the Z axis of the rocket body, m is the rocket mass (no power section before the fairing is separated, constant value), and delta WzAnd T is the control period.
(2) Because the engine does not work before the rocket fairing is separated and only receives aerodynamic force, the aerodynamic lateral force generated under the condition of small lateral slip angle can be expressed as:
whereinFor side slide by side forceThe derivative of the angle, β, is the actual sideslip angle of the rocket body, q is the dynamic pressure calculated by the rocket in real time, and S is the aerodynamic reference area of the rocket (which is a constant value).
(3) Estimate the derivative of the lateral force to the sideslip angle:
the rocket is estimated by adopting an approximate method, the trajectory of the rocket is stable before the fairing is separated, and the rocket is in the states of small attack angle, small sideslip and small rudder deflection,the aerodynamic data obtained by Mach number interpolation can be obtained by adopting the aerodynamic data when the attack angle α is 0 degrees, the sideslip angle β is 4 degrees and the rudder deviation is 0 degrees:
wherein C isz(Ma，α0°，β4°，0°) The lateral force of the rocket under different Mach numbers of α -0 degrees, β -4 degrees and 0 degrees is obtained by interpolation of an aerodynamic data table according to the Mach number, and Ma is the Mach number calculated by the rocket in real time.
(4) The simultaneous 1)2)3) can obtain the actual slip angle of the rocket body containing wind information:
(5) cowl separation front control sideslip angle:
ψ＝ψ0+kβ·β............................................5)
whereinψIn order to meet the requirement of the rudder turning angle of the yaw channel,ψ0yaw channel rudder yaw angle requirement, k, calculated for traditional PD control algorithmβTo design the sideslip angle control coefficient. Through the cooperative optimization design of the PD control coefficient and the sideslip angle control coefficient, the accurate control of the attitude angle, the angular speed, the sideslip angle and the like can be realized simultaneously.
Therefore, the sideslip angle control method for rocket fairing separation in windy conditions is realized, the sideslip angle can be controlled in a small range at the separation moment, and good conditions are created for rocket fairing separation.
Detailed Description
A sideslip angle control method for rocket fairing separation in windy conditions mainly comprises the following steps:
(1) solving the lateral force on the z axis of the rocket body:
wherein FzIs the lateral force on the Z axis of the rocket body, m is the rocket mass (no power section before the fairing is separated, constant value), and delta WzAnd T is the control period.
(2) Because the engine does not work before the rocket fairing is separated and only receives aerodynamic force, the aerodynamic lateral force generated under the condition of small lateral slip angle can be expressed as:
whereinThe derivative of the lateral force to the sideslip angle is shown as β, the actual sideslip angle of the rocket body is shown as q, the dynamic pressure calculated by the rocket machine in real time is shown as q, and S is the aerodynamic reference area (constant value) of the rocket.
(3) Estimate the derivative of the lateral force to the sideslip angle:
the rocket is estimated by adopting an approximate method, the trajectory of the rocket is stable before the fairing is separated, and the rocket is in the states of small attack angle, small sideslip and small rudder deflection,the aerodynamic number can be adopted when the angle of attack α is 0 °, the sideslip angle β is 4 °, and the rudder deflection is 0 °The Mach number interpolation is calculated to obtain:
wherein C isz(Ma，α0°，β4°，0°) The lateral force of the rocket under different Mach numbers of α -0 degrees, β -4 degrees and 0 degrees is obtained by interpolation of an aerodynamic data table according to the Mach number, and Ma is the Mach number calculated by the rocket in real time.
(4) The simultaneous 1)2)3) can obtain the actual slip angle of the rocket body containing wind information:
(5) cowl separation front control sideslip angle:
ψ＝ψ0+kβ·β..................................................5)
whereinψIn order to meet the requirement of the rudder turning angle of the yaw channel,ψ0yaw channel rudder yaw angle requirement, k, calculated for traditional PD control algorithmβTo design the sideslip angle control coefficient. Through the cooperative optimization design of the PD control coefficient and the sideslip angle control coefficient, the accurate control of the attitude angle, the angular speed, the sideslip angle and the like can be realized simultaneously.
Therefore, the sideslip angle control method for rocket fairing separation in windy conditions is realized, the sideslip angle can be controlled in a small range at the separation moment, and good conditions are created for rocket fairing separation.