CN117519270A - Attitude control system and method for vertical take-off and landing carrier rocket - Google Patents

Abstract

The invention discloses a posture control system and a posture control method for a vertical take-off and landing carrier rocket, belongs to the field of carrier rocket control, and is used for posture control of a novel reusable carrier recovery stage with control surfaces and vector technology. The attitude controller designed by the invention can be suitable for each task section in the recovery stage, and comprises a flight management system, an attitude controller and a control distributor, wherein the attitude controller is divided into three-way attitude loop controllers of an outer loop, namely pitch angle, roll angle and yaw angle controllers; an outer loop position loop controller; an inner loop angular rate loop controller and a yaw stability augmentation controller. The invention can fill the blank in the technical field of recycling of novel vertical lifting reusable carrier rockets, and has positive significance for engineering practice.

Description

Attitude control system and method for vertical take-off and landing carrier rocket

Technical Field

The invention belongs to the field of carrier rocket control, and particularly relates to a posture control system and method for a vertical take-off and landing carrier rocket.

Background

Since the first space travel of human beings, through continuous exploration and development for over sixty years, only two types of carriers which can execute space transportation tasks, namely a carrier rocket and a space shuttle, exist in the world so far, wherein the space shuttle can not be reused except for a small part of the space shuttle, and the maintenance cost of the space shuttle is very expensive, so that the space transportation cost is always high, and the pace of exploring outer space by human beings is greatly limited.

The novel vertical take-off and landing carrier rocket is a rocket capable of taking off vertically and landing vertically, and the purpose of recovering and recycling the first-level rocket can be achieved through vertical landing; the novel vertical take-off and landing carrier rocket is different from the traditional manned spacecraft which is recovered through a parachute after entering the atmosphere and is also different from the horizontal landing of a space shuttle at an airport, the vertical take-off and landing carrier rocket is a rotating body rocket body with a pneumatic control surface, the vertical landing is realized through the common control of the control surface and the vector thrust, and the process is more complicated than that of a general carrier rocket, and the novel vertical take-off and landing carrier rocket has the characteristics of model uncertainty, more external interference, severe parameter perturbation and the like, so that extremely strong nonlinearity brings great difficulty to the gesture control of the novel vertical take-off and landing carrier rocket.

Disclosure of Invention

The invention provides a posture control system and a posture control method for a vertical take-off and landing carrier rocket, which are based on an L1 self-adaptive control theory and an optimal control theory, and design a multichannel posture controller aiming at the vertical take-off and landing rocket so as to reduce design complexity of applying a plurality of single-channel posture controllers, obtain stronger robustness and control the flight posture of the rocket during vertical take-off and landing more stably.

In order to achieve the above purpose, the invention adopts the following technical scheme:

a attitude control system for a vertical take-off and landing launch vehicle, comprising: a flight management system, a attitude controller, and a control distributor;

the flight management system calls different control modes at different stages according to task demands or instruction demands, starts corresponding controllers and performs tracking control on control instructions;

the attitude controller comprises an outer loop attitude angle unit, an outer loop position loop unit, an inner loop angular rate unit and an stability enhancement control unit;

the outer loop attitude angle unit adopts a proportional integral PI control method, and specifically comprises the following steps:

an outer loop rolling channel control subunit, configured to calculate a deviation between the rolling angle instruction and a current rolling angle of the rolling channel, and output the calculated deviation to the inner loop rolling channel control subunit as an angular velocity control value of the rolling channel after the calculated deviation is subjected to a preset operation of an outer loop rolling channel gain control network and subtracted from angular velocity values of the pitch channel and the yaw channel due to a cross-linking branch;

an outer loop yaw channel control subunit, configured to calculate a deviation between the yaw angle command and a current yaw angle of the yaw channel, and output the calculated deviation to the inner loop yaw channel control subunit as an angular velocity control value of the yaw channel after the calculated deviation is subjected to a preset operation of an outer loop yaw channel gain control network and subtracted from a pitch angle velocity caused by a cross-linked branch on a pitch channel;

the outer loop pitch channel control subunit is used for calculating the deviation between the pitch angle instruction and the current pitch angle of the pitch channel, and outputting the calculated deviation to the inner loop pitch channel control subunit as an angular velocity control value of the pitch channel after the calculated deviation is subjected to operation of a preset outer loop pitch channel gain control network and added with the yaw angular velocity on the yaw channel caused by the cross-linked branch;

the inner loop angular rate unit adopts an L1 self-adaptive control method, and specifically comprises the following steps:

the inner loop rolling channel control subunit is used for calculating the deviation between the angular speed control value of the rolling channel and the current angular speed of the rolling channel, and outputting the calculated deviation after the calculated deviation is calculated by a preset rolling channel L1 self-adaptive controller;

the inner loop yaw channel control subunit is used for calculating the deviation between the angular speed control value of the yaw channel and the current angular speed of the yaw channel, and outputting the calculated deviation after the calculated deviation is calculated by a preset yaw channel L1 adaptive controller;

the inner loop pitching channel control subunit is used for calculating the deviation between the angular speed control value of the pitching channel and the current angular speed of the pitching channel, and outputting the calculated deviation after the calculated deviation is calculated by a preset pitching channel L1 self-adaptive controller;

the outer loop position loop unit adopts an LQR control method, and the attitude and position linear state space equation form under the emission coordinate system can be converted into four subsystems of axial direction, rolling, pitching and yawing respectively through simplified decoupling;

the stability augmentation control unit has the functions that: because the rocket recovery stage takes the requirement of fuel economy into consideration, unpowered downslide is adopted in the energy management stage, dynamic pressure is lower than that in the starting state of an engine, so that rudder efficiency can be attenuated, the attack angle is larger at the moment, the rolling can cause a non-negligible larger sideslip angle, and in order to eliminate the influence of p sin alpha, the rocket recovery stage is specially introduced into a yaw channel to cancel r cos alpha, so that a longitudinal channel and a transverse heading channel can be decoupled, and the adverse influence caused by rolling under a large attack angle is eliminated;

introducing yaw rate into the yaw channel to increase yaw damping to achieve the purpose of eliminating sideslip angle; due to the coupling effect of the yaw channel and the roll channel, the sideslip angle signal is introduced into the roll channel to enhance the roll static stability, and the roll angle rate is introduced into the roll channel to increase the roll damping, so that the Netherlands roll modal characteristics are improved, and the control equation is as follows:

wherein, delta _r 、δ _a Equivalent rudder deflection of the rudder and the aileron respectively; k (K) _r,r ，K _r,β Gain is controlled for the yaw path; k (K) _a,p ，K _a,β Gain control for the roll channel; g _f (s) is a transfer function.

The control distributor is used for controlling and distributing according to the output of the inner loop rolling channel control subunit, the inner loop yaw channel control subunit, the inner loop pitching channel control subunit and the engine throttle control subunit, and outputting corresponding control surface deflection instructions.

The beneficial effects are that: the invention provides a posture control system and a posture control method for a vertical take-off and landing carrier rocket, which are based on an L1 self-adaptive control theory and an optimal control theory, and a multichannel posture controller for the vertical take-off and landing rocket is designed, wherein the L1 self-adaptive control architecture solves the problems of inaccurate modeling, multiple external interference and severe parameter perturbation in the recovery process of a novel vertical take-off and landing rocket, meanwhile, compared with a traditional gain scheduling method, the L1 self-adaptive parameter adjustment is simpler and more convenient, only proper bandwidth is required to be selected according to flight quality standards, the trackability quality in a full envelope under fixed gain is ensured, and complicated gain scheduling is effectively avoided; the invention reduces the design complexity of applying a plurality of single-channel attitude controllers, obtains stronger robustness, more stably controls the flight attitude of the rocket during vertical take-off and landing, and can be suitable for each task section in the recovery stage; the method has good control effect on the attitude adjustment and control of the vertical take-off and landing carrier rocket in the full envelope flight state, fills the blank in the technical field of novel vertical take-off and landing reusable carrier rocket recovery, and has positive significance on engineering practice.

Drawings

FIG. 1 is a block diagram of an attitude control method according to an embodiment of the present invention;

FIG. 2 is a diagram of an adaptive control framework for the inner loop angular rate L1 in an embodiment of the present invention;

FIG. 3 is a diagram of an outer ring roll angle control framework in accordance with an embodiment of the present invention;

FIG. 4 is a diagram of an outer ring pitch control frame in an embodiment of the invention;

FIG. 5 is a diagram of an outer ring yaw control framework in an embodiment of the present invention;

FIG. 6 is a block diagram of an attitude control system according to an embodiment of the present invention.

Detailed Description

The invention is described in detail below with reference to the attached drawings and the specific embodiments:

as shown in fig. 6, a attitude control system for a vertical take-off and landing launch vehicle includes: a flight management system, a attitude controller, and a control distributor;

the flight management system calls different control modes at different stages according to task demands or instruction demands, starts corresponding controllers and performs tracking control on control instructions;

the attitude controller comprises an outer loop attitude angle unit, an outer loop position loop unit, an inner loop angular rate unit and an stability enhancement control unit;

the outer loop attitude angle unit adopts a proportional integral PI control method, and specifically comprises the following steps:

an outer loop rolling channel control subunit, configured to calculate a deviation between the rolling angle instruction and a current rolling angle of the rolling channel, and output the calculated deviation to the inner loop rolling channel control subunit as an angular velocity control value of the rolling channel after the calculated deviation is subjected to a preset operation of an outer loop rolling channel gain control network and subtracted from angular velocity values of the pitch channel and the yaw channel due to a cross-linking branch;

an outer loop yaw channel control subunit, configured to calculate a deviation between the yaw angle command and a current yaw angle of the yaw channel, and output the calculated deviation to the inner loop yaw channel control subunit as an angular velocity control value of the yaw channel after the calculated deviation is subjected to a preset operation of an outer loop yaw channel gain control network and subtracted from a pitch angle velocity caused by a cross-linked branch on a pitch channel;

the outer loop pitch channel control subunit is used for calculating the deviation between the pitch angle instruction and the current pitch angle of the pitch channel, and outputting the calculated deviation to the inner loop pitch channel control subunit as an angular velocity control value of the pitch channel after the calculated deviation is subjected to operation of a preset outer loop pitch channel gain control network and added with the yaw angular velocity on the yaw channel caused by the cross-linked branch;

the inner loop angular rate unit adopts an L1 self-adaptive control method, and specifically comprises the following steps:

the inner loop rolling channel control subunit is used for calculating the deviation between the angular speed control value of the rolling channel and the current angular speed of the rolling channel, and outputting the calculated deviation after the calculated deviation is calculated by a preset rolling channel L1 self-adaptive controller;

the inner loop yaw channel control subunit is used for calculating the deviation between the angular speed control value of the yaw channel and the current angular speed of the yaw channel, and outputting the calculated deviation after the calculated deviation is calculated by a preset yaw channel L1 adaptive controller;

the inner loop pitching channel control subunit is used for calculating the deviation between the angular speed control value of the pitching channel and the current angular speed of the pitching channel, and outputting the calculated deviation after the calculated deviation is calculated by a preset pitching channel L1 self-adaptive controller;

the system comprises a pitching, rolling and yawing three-channel attitude angle controller and an inner ring angular rate controller, wherein an inner ring angular rate module and an outer ring attitude angle module are introduced into four channels to be seen, and an elevator channel in the pitching channel is used for effectively controlling a pitch angle rate, a pitch angle and an attack angle; the throttle channel controls airspeed, the aileron channel controls rolling angle speed, rolling angle and track, the rudder channel controls yaw angle speed and yaw angle, and the aileron channel plays an auxiliary role in the transverse heading channel, increases Holland rolling damping and eliminates sideslip.

The outer loop position loop unit adopts an LQR control method, and the attitude and position linear state space equation form under the emission coordinate system can be converted into four subsystems of axial direction, rolling, pitching and yawing respectively through simplified decoupling; the position loop control module controls the three-axis positions of x, y and z by controlling the descending speed, the warp speed and the weft speed.

The stability augmentation control unit is used for decoupling the longitudinal channel from the transverse direction channel by introducing the rolling angle rate p into the yaw channel to cancel r cos alpha, so that the attitude control under a large attack angle is facilitated; the function is as follows: because the rocket recovery stage takes the requirement of fuel economy into consideration, unpowered downslide is adopted in the energy management stage, dynamic pressure is lower than that in the starting state of an engine, so that rudder efficiency can be attenuated, the attack angle is larger at the moment, the rolling can cause a non-negligible larger sideslip angle, and in order to eliminate the influence of p sin alpha, the rocket recovery stage is specially introduced into a yaw channel to cancel r cos alpha, so that a longitudinal channel and a transverse heading channel can be decoupled, and the adverse influence caused by rolling under a large attack angle is eliminated;

introducing yaw rate into the yaw channel to increase yaw damping to achieve the purpose of eliminating sideslip angle; due to the coupling effect of the yaw channel and the roll channel, the sideslip angle signal is introduced into the roll channel to enhance the roll static stability, and the roll angle rate is introduced into the roll channel to increase the roll damping, so that the Netherlands roll modal characteristics are improved, and the control equation is as follows:

wherein delta _r 、δ _a Equivalent rudder deflection of the rudder and the aileron respectively; k (K) _r,r ，K _r,β Gain is controlled for the yaw path; k (K) _a,p ，K _a,β Gain control for the roll channel; g _f (s) is a transfer function;

the control distributor is used for controlling and distributing according to the output of the inner loop rolling channel control subunit, the inner loop yaw channel control subunit, the inner loop pitching channel control subunit and the engine throttle control subunit, and outputting corresponding control surface deflection instructions.

As shown in fig. 1, the attitude control method of the system for the vertical take-off and landing carrier rocket comprises the following steps: the flight management system gives out control instructions, the control instructions are resolved in real time through each subsystem controller and then are subjected to feedback adjustment, the resolved control instructions are finally transmitted to the control distributor, the control instructions are converted into real control surface instructions through the virtual rudder instructions, and the real control surface instructions are input to the execution mechanism to complete attitude control and adjustment of the rocket.

The L1 self-adaptive control method adopted by the inner loop angular rate unit is quick and robust self-adaptive control, model reference self-adaptation is improved, and the separation of control law and self-adaptive law design is ensured by adding a low-pass filter in a control law design link; the state observer is designed to estimate uncertain parameters in the controlled object, so that the output errors of the state observer and the controlled object are ensured to be stable in the Lyapunov sense, an adaptive law is obtained, and meanwhile, when the adaptive gain is large enough, the system can be ensured to have good transient performance through mathematics; as shown in fig. 2, the L1 adaptive control is divided into the following four parts:

controlled objectWherein A is _m The control law of L1 self-adaptive control needs all state information of the controlled object, so that mathematical modeling is carried out on the controlled object by using a state space expression form, and uncertainty of the controlled object parameters is described by omega, theta and sigma;

state observerWherein (1)>The estimated values of variables in the corresponding controlled object respectively tend to infinity in time, the controlled object and the state observer have consistent dynamic characteristics, and the estimated deviation is stable in the sense of Lyapunov;

the adaptive law link uses the error between the state observer and the controlled objectAs main input, it is ensured that it is stable in the sense of Lyapunov to obtain the estimated parameter +.>Mathematical expression, and simultaneously, estimated parameters are also used in the control law to ensure the input and output stability of the closed-loop control system.

The control law consists of two parts: one is reconstruction of the reference input that matches the state observer; the second is a low-pass filtering link; the former is calculated by substitution of mathematical expression, so that estimated parameters are canceled, and reference input to the output of a state observer is ensuredIs stable, then can guarantee in the adaptive law link and state predictor designWhen stable in the sense of Lyapunov, the L1 self-adaptive closed-loop system is also stable in input and output; the latter design is used for guaranteeing the separation design of control law and self-adaptation law, and when increasing self-adaptation parameter and guaranteeing the good transient performance of system, can avoid the high frequency oscillation of system input signal, guarantee that the system has good transient state and dynamic performance.

As shown in fig. 3, the roll angle control framework designs the roll angle control law as follows:

p _c ＝k _φ (φ _c -φ)-tanθ(q sinφ+r cosφ)

wherein k is _φ To control bandwidth, phi for roll angle loop _c The roll angle command given to the fly-pipe system is phi the roll angle feedback value, theta the pitch angle, q the pitch angle rate, r the yaw angle rate, p _c A roll angle rate command generated by the roll angle circuit; it should be noted that the bandwidth of the pitch rate control loop is typically 3 to 5 times the pitch loop bandwidth.

The pitch angle control loop adopts a proportional control structure, the angular velocity loop is L1 self-adaptive control, as shown in FIG. 4, and the pitch angle control frame derives the pitch angle control law as follows:

wherein k is _θ For pitch loop control bandwidth, θ _c Give out for the fly-pipe systemIs the pitch angle command, θ is the pitch angle feedback value, φ is the roll angle, r is the yaw rate, q _c A pitch rate command generated by the pitch loop. It should be noted that the bandwidth of the pitch rate control loop is typically 3 to 5 times the pitch loop bandwidth.

The yaw control loop adopts a proportional control structure, the angular velocity loop is L1 self-adaptive control, as shown in figure 5, the yaw control framework derives a yaw control law as follows,

wherein k is _ψ Control bandwidth, ψ, for pitch loop _c For yaw angle command, ψ is yaw angle feedback value, q is pitch rate, r _c A yaw rate command generated by the yaw rate circuit. It should be noted that the bandwidth of the yaw rate control loop is typically chosen to be 3-5 times the bandwidth of the yaw rate loop;

the position ring unit is designed by adopting an LQR control method, and a state space equation form after the posture and the position under the emission coordinate system are simplified and decoupled to obtain the following forms, namely an axial system, a rolling system, a pitching system and a yawing system, wherein the specific state matrix expression is as follows in sequence:

wherein,is x-axis acceleration; y is _d And z _d Is the y, z axial position; a is that _t Is aerodynamic force acting on the resistance control surface; d, d _x 、d _y The vector diameter from the mass center to the center of the control surface; delta _x 、δ _y And delta _z Is a triaxial control amount.

The task sections of the vertical take-off and landing rocket in the recovery section are multiple and the control inputs of the task sections are different, so that the problem of the control difficulty of the multiple and complicated input quantity is faced, and a control allocation strategy based on virtual rudder mapping is provided according to the idea of decoupling three channels of roll, pitch and yaw according to the problem, wherein the mapping matrix is as follows:

wherein duo_q1 is the left rudder deflection amount; duo_q2 is the right rudder deflection amount; duo_h1 is the left rear rudder deflection; duo_h2 is the left rear rudder deflection; ele_l is the deflection of the left vectoring nozzle in the up-down direction; azi_l is the left-right deflection of the left vectoring nozzle; ele_r and azi_r are the amount of deflection of the right vectoring nozzle up and down and left and right, respectively.

The recovery stage is mainly divided into an unpowered downslide stage and a powered downslide stage, wherein in the motion process of the two stages, in the former stage, in order to save fuel, the attitude is controlled by adopting a resistance rudder deflection mode, and in the latter stage, the attitude is controlled by adopting a vector engine spray pipe deflection mode;

in the unpowered downslide stage, the two front rudders are asymmetrically deflected to control yaw, the front control surface and the rear control surface are symmetrically deflected to control pitch, at the moment, pneumatic analysis shows that pitching movement can be completed by simultaneously symmetrically deflecting only the two rear rudders, and coupling does not occur in order to control transverse and longitudinal directions, so that the two front rudders are not considered to control pitch, and finally, the two rear rudders are asymmetrically deflected to control rolling, at the moment, if yaw occurs, sideslip can be eliminated by fine tuning of the front rudders;

in the powered downslide stage, the two vectoring engine spray pipes deflect leftwards and rightwards to control yaw, deflect upwards and downwards to control pitch, and the two engines deflect upwards and downwards asymmetrically to control roll.

In summary, the control instruction is given by the fly-pipe system, the feedback adjustment is carried out after the real-time calculation by each subsystem controller, the calculated control instruction is finally transmitted to the control distributor, the control instruction is converted into the real control surface instruction by the virtual rudder instruction, and the real control surface instruction is input to the execution mechanism to complete the attitude control and adjustment of the rocket. The invention has good control effect on the attitude adjustment and control of the vertical take-off and landing carrier rocket in the full envelope flight state, and has certain engineering significance.

The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.

Claims (10)

1. A attitude control system for a vertical take-off and landing launch vehicle, comprising: a flight management system, a attitude controller, and a control distributor; the flight manager gives out a control instruction and transmits the control instruction to the gesture controller, the gesture controller carries out feedback adjustment on real-time calculation and reception of the received control instruction and then transmits the control instruction to the control distributor, and the control distributor retransmits the control surface instruction to the executing mechanism.

2. The attitude control system for a vertical take-off and landing launch vehicle according to claim 1, wherein said attitude controller comprises an outer loop attitude angle unit, an outer loop position loop unit, an inner loop angular rate unit and an stability augmentation control unit; the external loop attitude angle unit transmits the resolved instruction to the internal loop angular rate unit, and the stability enhancement control unit is positioned in the external loop attitude angle unit and is used for eliminating adverse effects caused by rolling under a large attack angle; the outer loop position loop unit controls the three-axis positions of x, y and z by controlling the descent rate, the warp rate and the weft rate.

3. The attitude control system for a vertical take-off and landing launch vehicle according to claim 2, wherein said outer loop attitude angle unit includes:

an outer loop rolling channel control subunit, configured to calculate a deviation between the rolling angle instruction and a current rolling angle of the rolling channel, and output the calculated deviation to the inner loop rolling channel control subunit as an angular velocity control value of the rolling channel after the calculated deviation is subjected to a preset operation of an outer loop rolling channel gain control network and subtracted from angular velocity values of the pitch channel and the yaw channel due to a cross-linking branch;

an outer loop yaw channel control subunit, configured to calculate a deviation between the yaw angle command and a current yaw angle of the yaw channel, and output the calculated deviation to the inner loop yaw channel control subunit as an angular velocity control value of the yaw channel after the calculated deviation is subjected to a preset operation of an outer loop yaw channel gain control network and subtracted from a pitch angle velocity caused by a cross-linked branch on a pitch channel;

the outer loop pitch channel control subunit is used for calculating the deviation between the pitch angle instruction and the current pitch angle of the pitch channel, calculating the calculated deviation through a preset outer loop pitch channel gain control network, adding the calculated deviation with the yaw angular velocity caused by the cross-linked branch on the yaw channel, and outputting the calculated deviation to the inner loop pitch channel control subunit as an angular velocity control value of the pitch channel.

4. The attitude control system for a vertical take-off and landing launch vehicle according to claim 2, wherein said inner loop angular rate unit comprises:

the inner loop rolling channel control subunit is used for calculating the deviation between the angular speed control value of the rolling channel and the current angular speed of the rolling channel, and outputting the calculated deviation to the control distributor after the calculated deviation is calculated by a preset rolling channel L1 self-adaptive controller;

the inner loop yaw channel control subunit is used for calculating the deviation between the angular speed control value of the yaw channel and the current angular speed of the yaw channel, and outputting the calculated deviation to the control distributor after the calculated deviation is calculated by a preset yaw channel L1 self-adaptive controller;

the inner loop pitching channel control subunit is used for calculating the deviation between the angular speed control value of the pitching channel and the current angular speed of the pitching channel, and outputting the calculated deviation to the control distributor after the calculated deviation is calculated by a preset pitching channel L1 self-adaptive controller.

5. A method of attitude control for a vertical take-off and landing launch vehicle according to any one of claims 1 to 4, comprising the steps of:

the flight management system calls different control modes at different stages according to task demands or instruction demands, starts corresponding controllers and performs tracking control on control instructions;

and the control instruction given by the flight management system is resolved in real time by the attitude controller and then is fed back and adjusted, the resolved control instruction is finally transmitted to the control distributor, is converted into a real control surface instruction by the virtual rudder instruction, and is input to the execution mechanism to complete the attitude control and adjustment of the rocket.

6. The attitude control method for a vertical take-off and landing launch vehicle according to claim 5, wherein,

the roll angle control frame designs the roll angle control law as follows:

p _c ＝k _φ (φ _c -φ)-tanθ(q sinφ+r cosφ)

wherein k is _φ To control bandwidth, phi for roll angle loop _c The roll angle command given to the fly-pipe system is phi the roll angle feedback value, theta the pitch angle, q the pitch angle rate, r the yaw angle rate, p _c A roll angle rate command generated by the roll angle circuit;

the pitch angle control loop adopts a proportional control structure, the angular velocity loop is L1 self-adaptive control, and the pitch angle control frame derives the pitch angle control law as follows:

wherein k is _θ For pitch loop control bandwidth, θ _c For the pitch angle command given by the fly-pipe system, θ is the pitch angle feedback value, φ is the roll angle, r is the yaw rate, q _c A pitch rate command generated by the pitch loop;

the yaw angle control loop adopts a proportional control structure, the angular velocity loop is L1 self-adaptive control, the yaw angle control framework derives the yaw angle control law as follows,

wherein k is _ψ Control bandwidth, ψ, for pitch loop _c For yaw angle command, ψ is yaw angle feedback value, q is pitch rate, r _c A yaw rate command generated by the yaw rate circuit.

7. The attitude control method for a vertical take-off and landing launch vehicle according to claim 6, wherein a yaw rate is introduced into the yaw passage to increase yaw damping for the purpose of eliminating the sideslip angle; due to the coupling effect of the yaw channel and the roll channel, the sideslip angle signal is introduced into the roll channel to enhance the roll static stability, and the roll angle rate is introduced into the roll channel to increase the roll damping, so that the Netherlands roll modal characteristics are improved, and the control equation is as follows:

wherein, delta _r 、δ _a Equivalent rudder deflection of the rudder and the aileron respectively; k (K) _r,r ，K _r,β Gain is controlled for the yaw path; k (K) _a,p ，K _a,β Gain control for the roll channel; g _f (s) is a transfer function.

8. The attitude control method for a vertical take-off and landing launch vehicle according to claim 5, wherein the virtual rudder command is converted into a control allocation strategy based on virtual rudder mapping in the real control surface command, and the mapping matrix is as follows:

wherein duo_q1 is the left rudder deflection amount; duo_q2 is the right rudder deflection amount; duo_h1 is the left rear rudder deflection; duo_h2 is the left rear rudder deflection; ele_l is the deflection of the left vectoring nozzle in the up-down direction; azi_l is the left-right deflection of the left vectoring nozzle; ele_r and azi_r are the amount of deflection of the right vectoring nozzle up and down and left and right, respectively.

9. The attitude control method for a vertical take-off and landing launch vehicle according to claim 5, wherein the position loop unit adopts an LQR control method, and the attitude and position-linearized state space equation form under the launching coordinate system is simplified and decoupled to obtain the following forms, which are respectively an axial, a roll, a pitch and a yaw system, and the specific state matrix expressions are as follows in sequence:

wherein,is x-axis acceleration; y is _d And z _d Is the y, z axial position; a is that _t Is aerodynamic force acting on the resistance control surface; d, d _x 、d _y The vector diameter from the mass center to the center of the control surface; delta _x 、δ _y And delta _z Is a triaxial control amount.

10. The attitude control method for a vertical take-off and landing launch vehicle according to claim 9, wherein,

the rocket recovery stage is divided into an unpowered gliding stage and a powered gliding stage; the unpowered downslide stage adopts a resistance rudder deflection mode to control the gesture, and the powered downslide stage adopts a vector engine spray pipe deflection mode to control the gesture;

the two rudders in the unpowered glide phase are asymmetrically deflected to control yaw; the two rear rudders are symmetrically deflected at the same time to finish pitching motion; the two rear rudders are asymmetrically deflected to control rolling, and sideslip can be eliminated by fine adjustment of the front rudders if yaw occurs;

in the powered downslide stage, the two vectoring engine spray pipes deflect leftwards and rightwards to control yaw, deflect upwards and downwards to control pitch, and the two engines deflect upwards and downwards asymmetrically to control roll.