CN117234070B - BTT distribution method based on angle control instruction - Google Patents

Abstract

The invention discloses a BTT allocation method based on angle control instructions. First, the ballistic inclination and ballistic deflection angle instructions are used to generate attack angle and sideslip angle instructions based on the actual ballistic inclination and ballistic deflection angle deviations; and then combined with Mach and full missile normal direction The force coefficient converts the angle of attack and sideslip angle commands into normal force coefficient and lateral force coefficient commands. According to the normal force coefficient commands required in the pitch and yaw directions, the roll angle command and the resultant force coefficient command can be calculated; finally, it is passed again The corresponding relationship between the full-bomb normal force coefficient and the angle of attack converts the required force coefficient command into an angle of attack command and introduces it to the controller, enabling fast tracking of the command during flight and accurate BTT coordinated turning control. The controller design method has a universal structure and strong engineering practice capabilities. It can be widely used in the design of various plane-symmetric hypersonic aircraft guidance and control systems in the future.

Description

A BTT allocation method based on angle control instructions

Technical field

The invention belongs to the technical field of aircraft, and specifically relates to a BTT allocation method based on angle control instructions.

Background technique

The position, speed, and attitude of a symmetrical hypersonic aircraft change drastically during flight. At the same time, the bank-and-turn technology (BTT) is used, which places higher requirements on the rapidity of the control system. The traditional plane-symmetrical hypersonic aircraft adopts the overload form of BTT allocation method, resulting in the pitch channel controller can only use the overload control form. The speed of the control system is completely limited by the cutoff frequency of the overload control system, and the bandwidth of the control system cannot be reduced. improve.

Contents of the invention

In order to overcome the shortcomings of the existing technology, the present invention provides a BTT allocation method based on angle control instructions. First, the ballistic inclination angle and ballistic declination angle instructions are used to generate attack angle and sideslip angle instructions using the actual ballistic inclination angle and ballistic declination angle deviations; Then combine the Mach and full-bomb normal force coefficients to convert the angle of attack and sideslip angle commands into normal force coefficient and lateral force coefficient commands. The roll angle command can be calculated based on the normal force coefficient commands required in the pitch and yaw directions. and the resultant force coefficient command; finally, through the corresponding relationship between the full bomb normal force coefficient and the angle of attack, the required force coefficient command is converted into an angle of attack command and introduced into the controller to achieve fast tracking of the command during flight and accurately realize BTT Coordinated turning control. This controller design method has a universal structure and strong engineering practice capabilities. It can be widely used in the design of various plane-symmetric hypersonic aircraft guidance and control systems in the future.

The technical solution adopted by the present invention to solve the technical problems includes the following steps:

Step 1: Generate ballistic inclination and ballistic deflection angle instructions;

Use the flight time as the independent variable to design the ballistic inclination angle and ballistic deflection angle. The design time table , the corresponding ballistic inclination number table and ballistic deflection angle number table are/> , ;n represents the dimension of the designed table;

According to the guided rocket flight time Perform one-dimensional interpolation to generate ballistic inclination angle instructions and ballistic deflection angle instructions:

in (.) is a one-dimensional interpolation function,/> They are the ballistic inclination angle command and ballistic deflection angle command at the current moment;

Step 2: Calculate the angle of attack command and sideslip angle command;

Convert the ballistic inclination angle command and ballistic deflection angle command into the angle of attack command and sideslip angle command. The conversion relationship is as follows:

in ,/> They are the angle of attack command and sideslip angle command at the current moment,/> are the ballistic inclination angle and ballistic deflection angle at the current moment, respectively,/> for flight control gain;

Step 3: Calculate the roll angle command;

Combining the current flight Mach number with the angle of attack command and sideslip angle command, the normal force coefficient and lateral force coefficient command at the current moment are calculated:

in is the flight Mach number at the current moment,/> is the normal force coefficient in aerodynamic data, and its form is a two-dimensional table of Mach number and angle of attack,/> They are the normal force coefficient commands required in the pitch and yaw directions respectively;

Calculate the roll angle command according to the normal force coefficient command required in the pitch and yaw directions. The roll angle command The expression is as follows:

Step 4: Calculate the pitch channel angle of attack command;

To synthesize the pitch and yaw channel commands into pitch pilot control commands, first synthesize the force coefficients:

Then interpolate from the aerodynamic data to obtain the angle of attack command corresponding to the normal force coefficient command. :

Step 5: Instruction tracking control;

will command Bringing it into the flight control system, angular velocity feedback realizes compound stability control of the missile body. The control law of the control system is:

in Both are flight control system gains,/> is the pitch angular velocity signal.

The beneficial effects of the present invention are as follows:

The invention effectively improves the speed of the control system, meets the requirements of the guided rocket control system, and has broad application prospects.

Description of the drawings

Figure 1 is a structural diagram of the BTT allocation strategy of the present invention.

Figure 2 is a structural diagram of the pitch channel control system of the present invention.

Figure 3 is a comparison curve of ballistic inclination angle according to the embodiment of the present invention.

Figure 4 is a ballistic deflection angle comparison curve according to the embodiment of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and examples.

In order to solve the problem of rapid overload controller bandwidth limitation of traditional planar symmetric hypersonic aircraft BTT controller, it is necessary to conduct simple, universal and effective improvement research on the aircraft controller design method and BTT allocation method. The present invention provides a BTT allocation method based on angle control instructions. The angle of attack and sideslip angle instructions are generated from the ballistic inclination angle and the ballistic deflection angle deviation. By introducing the corresponding relationship between the angle of attack and sideslip angle instructions and the normal force coefficient, the angle The command is converted into a force coefficient command for BTT distribution, thereby effectively achieving fast and precise control of the angle of the plane-symmetric hypersonic aircraft. The innovation of this control method is that it makes full use of the rapidity of the angle control loop and performs BTT allocation based on the angle to improve the performance of the plane-symmetric hypersonic aircraft control system.

As shown in Figure 1, a BTT allocation method based on angle control instructions includes the following steps:

Step 1: Generate ballistic inclination and ballistic deflection angle instructions;

Use the flight time as the independent variable to design the ballistic inclination angle and ballistic deflection angle. The design time table , the corresponding ballistic inclination and ballistic deflection angle tables are/> , . If no lateral maneuver is performed, the ballistic deflection angle command can be set to 0.

According to the guided rocket flight time Perform one-dimensional interpolation to generate ballistic inclination and ballistic deflection angle commands.

in is a one-dimensional interpolation function,/> They are respectively the ballistic inclination angle command and the ballistic deflection angle command at the current moment.

Step 2: Calculate the angle of attack command and sideslip angle command;

Convert the ballistic inclination angle command and ballistic deflection angle command into the angle of attack command and sideslip angle command. The conversion relationship is as follows:

in ,/> They are the angle of attack command and sideslip angle command at the current moment,/> are the ballistic inclination angle and ballistic deflection angle at the current moment, respectively,/> for flight control gain;

Step 3: Calculate the roll angle command;

Since the roll angle command cannot be calculated directly through the angle of attack and sideslip angle commands, there is a mapping relationship between the angle of attack and the sideslip angle in the aerodynamic data, and there is a direct expression between the force and the roll angle, which can be calculated through the mapping relationship. Roll angle command.

The aerodynamic data of hypersonic aircraft includes normal force coefficients at different angles of attack and different Mach numbers. In the aerodynamic data, the current flight Mach number, angle of attack, and sideslip angle commands are combined to calculate the normal force coefficient and lateral force coefficient commands at the current moment.

in is the flight Mach number at the current moment,/> is the normal force coefficient in aerodynamic data, and its form is a two-dimensional table of Mach number and angle of attack,/> They are the normal force coefficient commands required in the pitch and yaw directions respectively;

The roll angle command can be calculated based on the normal force coefficient commands required in the pitch and yaw directions. The roll angle command The expression is as follows:

Step 4: Calculate the pitch channel angle of attack command;

During the turning process, the yaw pilot must ensure zero sideslip angle and play a role in coordinating the turning. The commands required for the pitch and yaw channels are all implemented in the pitch pilot, so the pitch and yaw channel commands need to be synthesized into pitch pilot control commands; first, the force coefficients are synthesized:

Then interpolate from the aerodynamic data to obtain the angle of attack command corresponding to the normal force coefficient command. :

Step 5: Instruction tracking control;

will command Bring in the flight control system, its composition principle is shown in Figure 2. Angular velocity feedback realizes composite stability control of the projectile. The control law of the control system is:

in Gain for the flight control system,/> is the pitch angular velocity signal.

Example:

The present invention will be further described with reference to a certain guided rocket system example.

The guided rocket launch point is 0m above sea level and climbs to the designated position.

Step 1: Generate ballistic inclination and ballistic deflection angle instructions;

Design timetable , the corresponding ballistic inclination angle is/> , the ballistic deflection angle command is selected as the sight angle/> .

According to the guided rocket flight time Perform one-dimensional interpolation to generate ballistic tilt angle instructions.

Step 2: Calculate the angle of attack and sideslip angle commands;

Select , convert the ballistic inclination angle and ballistic deflection angle commands into attack angle commands. The conversion relationship is as follows:

Step 3: Calculate the roll angle command;

In the aerodynamic data, combined with the current flight Mach number, angle of attack, and sideslip angle commands, the normal force coefficient and lateral force coefficient commands at the current moment are calculated:

Among them, different angles of attack in the aerodynamic data and different Mach numbers The normal force coefficient is as follows:

The roll angle command can be calculated based on the normal force coefficient commands required in the pitch and yaw directions. The roll angle command The expression is as follows:

Step 4: Calculate the pitch channel angle of attack command;

Its force coefficients are synthesized.

Then use aerodynamic data to calculate the normal force coefficients in The corresponding angle of attack below :

in Represents the normal force coefficient/> First row element, second row element, third row element, fourth row element and fifth row element.

Then interpolate according to the current flight Mach number to obtain the angle of attack command. :

Step 5: Instruction tracking control;

will command Bring in the flight control system, its composition principle is shown in Figure 2. Angular velocity feedback realizes compound stability control of the projectile. The control law of the control system is:

In order to verify the performance of the present invention, simulations of the BTT distribution method proposed by the present invention and the BTT control method based on overload control were performed respectively. After digital simulation comparison, the curves in Figures 3 to 4 were obtained. It can be seen from the simulation results that the angle-based BTT allocation method designed in the present invention can effectively improve the speed of the control system.

Claims (1)

1. The BTT distribution method based on the angle control instruction is characterized by comprising the following steps of:

step 1: generating a ballistic dip angle instruction;

design the inclination angle of trajectory and deflection angle of trajectory by taking flight time as independent variable, design time tableThe corresponding ballistic dip angle tables and the ballistic deflection angle tables are +.>，The method comprises the steps of carrying out a first treatment on the surface of the n represents the dimension of the designed number of tables;

according to guided rocket flight timePerforming one-dimensional interpolation to generate a ballistic dip angle instruction and a ballistic deflection angle instruction:

；

wherein the method comprises the steps of() is a one-dimensional interpolation function, +.>The trajectory inclination angle instruction and the trajectory deflection angle instruction at the current moment are respectively;

step 2: calculating an attack angle instruction and a sideslip angle instruction;

the ballistic inclination angle instruction and the ballistic deflection angle instruction are converted into attack angle instruction and sideslip angle instruction, and the conversion relationship is as follows:

；

wherein the method comprises the steps of、/>An attack angle instruction and a sideslip angle instruction at the current moment, respectively,>the ballistic inclination angle and the ballistic deflection angle at the current moment are respectively +.>Gain for flight control;

step 3: calculating a roll angle instruction;

and calculating a normal force coefficient and a lateral force coefficient instruction at the current moment by combining the current flight Mach number, the attack angle instruction and the sideslip angle instruction:

；

wherein the method comprises the steps ofFor the current moment flight Mach number>Is the normal force coefficient in the pneumatic data,two-dimensional table in the form of Mach number and angle of attack, +.>Normal force coefficient instructions required by pitching and yawing directions respectively;

calculating a roll angle command according to a normal force coefficient command required by the pitching and yawing directionsThe expression is as follows:

；

step 4: calculating a pitch channel attack angle instruction;

synthesizing a pitching and yawing channel instruction into a pitching pilot control instruction, and firstly synthesizing a force coefficient:

；

then, an attack angle instruction corresponding to the normal force coefficient instruction is obtained by interpolation from the pneumatic data：

；

Step 5: instruction tracking control;

will instructThe method is brought into a flight control system, the composite stability enhancement control of the projectile body is realized through angular velocity feedback, and the control law of the control system is as follows:

；

wherein the method comprises the steps ofAll are flight control system gains->Is a pitch angle rate signal.