Vehicle-mounted tail-push rotor unmanned aerial vehicle and control method of vehicle-mounted tail-push rotor unmanned aerial vehicle

Abstract

The invention discloses a vehicle-mounted tail-propelled rotor unmanned aerial vehicle and a control method of the unmanned aerial vehicle, a tail-propelled rotor is added at the tail of the rotor unmanned aerial vehicle, and the method comprises the following steps: establishing a vehicle-mounted tail-propelled rotor unmanned aerial vehicle model; according to the vehicle-mounted tail thrust rotor unmanned aerial vehicle model, an unmanned aerial vehicle state space system in a balance state is obtained, the balance state refers to the state of the unmanned aerial vehicle when the pitch angle of the unmanned aerial vehicle is zero, and the obtained unmanned aerial vehicle state space system comprises a transverse subsystem and a longitudinal subsystem; on the basis of an unmanned aerial vehicle state space system, an inner ring control structure is arranged to control the transverse subsystem, an outer ring control structure is arranged to control the longitudinal subsystem, and therefore control over the pose of the unmanned aerial vehicle is achieved. According to the vehicle-mounted tail thrust rotor unmanned aerial vehicle and the control method of the unmanned aerial vehicle, the fuselage can be parallel to the horizontal plane while movement of the fuselage is kept, and the unmanned aerial vehicle can land on the vehicle conveniently.

Description

Technical Field

[0001] The present invention relates to an in-vehicle tail-push rotor unmanned aerial vehicle and a control method thereof, belonging to the technical field of aircraft control. Background Art

[0002] Most of the existing unmanned aerial vehicles are quadrotors. In the traditional control method of quadrotor unmanned aerial vehicles, pitching angle changes are used for forward flight and backward flight.

[0003] However, when traditional quadrotor unmanned aerial vehicles and traditional control methods are applied to in-vehicle unmanned aerial vehicles, the fuselage cannot be parallel to the vehicle during forward flight, which may easily cause lateral collision and damage during landing.

[0004] Therefore, it is necessary to conduct in-depth research on existing in-vehicle quadrotor unmanned aerial vehicles and their control methods to solve the above problems. Summary of the Invention

[0005] To overcome the above problems, the inventors have conducted in-depth research and proposed an in-vehicle tail-push rotor unmanned aerial vehicle, with a tail-push rotor added to the tail of the rotor unmanned aerial vehicle. The tail-push rotor is located on the central vertical plane of the unmanned aerial vehicle, and the force generated by the tail-push rotor passes through the center of mass of the airframe and points directly in front of the unmanned aerial vehicle.

[0006] The present invention also provides a control method for an in-vehicle tail-push rotor unmanned aerial vehicle, which includes the following steps:

[0007] Establish an in-vehicle tail-push rotor unmanned aerial vehicle model;

[0008] According to the in-vehicle tail-push rotor unmanned aerial vehicle model, obtain the state space system of the unmanned aerial vehicle in the balanced state. The balanced state refers to the state of the unmanned aerial vehicle when the pitching angle is zero. The obtained state space system of the unmanned aerial vehicle includes a lateral subsystem and a longitudinal subsystem;

[0009] Based on the state space system of the unmanned aerial vehicle, set an inner-loop control structure to control the lateral subsystem, and set an outer-loop control structure to control the longitudinal subsystem, so as to realize the control of the pose of the unmanned aerial vehicle.

[0010] In a preferred embodiment, the in-vehicle tail-push rotor unmanned aerial vehicle model includes a control allocation sub-model, a blade dynamics sub-model, and a rigid body dynamics sub-model of the tail-push rotor unmanned aerial vehicle;

[0011] The in-vehicle tail-push rotor unmanned aerial vehicle model includes a control allocation sub-model, a blade dynamics sub-model, and a rigid body dynamics sub-model of the tail-push rotor unmanned aerial vehicle,

[0012] The blade dynamics sub-model is used to describe the relationship between the rotational speeds of the rotor motors and the tail-push motor and the generated forces and torques,

[0013] The control allocation sub-model is used to allocate the UAV channel control instructions to the rotor motors and the tail thrust motor.

[0014] In a preferred embodiment, the rigid body dynamics sub-model of the tail thrust rotor UAV is expressed as:

[0015]

[0016] Wherein, u, v, and w are the projections of the UAV speed in the body coordinate system, p, q, and r are the projections of the UAV angular velocity of rotation in the body coordinate system, F x , F y , F z are the projections of the forces generated by the rotors in the body coordinate system, L, M, and n are the projections of the torques generated by the rotors in the body coordinate system, L is the thrust of the tail thrust rotor, D x , D y , D z are the projections of the aerodynamic drags on the fuselage in the body coordinate system, is the projection of the aerodynamic moment on the fuselage in the body coordinate system, is the inertia matrix of the UAV, Ω i (i = 1, 2, 3, 4) are the rotational speeds of the four rotor motors, I r represents the moment of inertia of a single rotor motor, and are the gyroscopic torques generated by the rotation of the blade, is the reaction torque generated during the acceleration and deceleration of the blade, g is the acceleration due to gravity, m is the mass of the UAV, θ is the pitch angle of the UAV, ψ is the roll angle of the UAV, and φ is the yaw angle of the UAV.

[0017] In a preferred embodiment, the blade dynamics sub-model is expressed as:

[0018]

[0019] Wherein, ρ represents the air density, Ω represents the rotational speed of the corresponding motor, R represents the radius of the rotor blade, C T represents the lift coefficient of the rotor, T b represents the lift generated by the rotor, C H represents the lateral force generated by the rotor, H p represents the lateral force generated by the rotor, C Q represents the reaction torque of the rotor, Q p represents the torque generated by the rotor, represents the pitch moment coefficient of the rotor, M yp represents the pitch moment generated by the rotor, represents the roll moment coefficient of the rotor, M xpIndicates the rolling moment generated by the rotor.

[0020] In a preferred embodiment, the control allocation sub-model is expressed as:

[0021]

[0022] Where, Ω1 represents the rotational speed of the main rotor 1 motor, Ω2 represents the rotational speed of the main rotor 2 motor, Ω3 represents the rotational speed of the main rotor 3 motor, Ω4 represents the rotational speed of the main rotor 4 motor, Ω tail Represents the rotational speed of the tail thrust motor, R mixer Represents the control allocation matrix, δ lat Represents the control command for the roll channel, δ lon Represents the control command for the pitch channel, δ ped Represents the control command for the yaw channel, δ col Represents the control command for the altitude channel, δ tail Represents the control command for the tail thrust throttle.

[0023] In a preferred embodiment, the UAV state space system is obtained, expressed as:

[0024]

[0025]

[0026] Where, Y v Represents the derivative of the force on the Y-axis of the body frame in the equilibrium state with respect to the Y-axis velocity, Represents the X-axis velocity of the body frame in the equilibrium state, L v Represents the derivative of the moment of force on the X-axis of the body frame in the equilibrium state with respect to the Y-axis velocity, L p Represents the derivative of the moment of force on the X-axis of the body frame in the equilibrium state with respect to the X-axis angular velocity, L r Represents the derivative of the moment of force on the X-axis of the body frame in the equilibrium state with respect to the Z-axis angular velocity, L lat Represents the derivative of the moment of force on the X-axis of the body frame in the equilibrium state with respect to the roll command, L ped Represents the derivative of the moment of force on the X-axis of the body frame in the equilibrium state with respect to the yaw command, N v Represents the derivative of the moment of force on the Z-axis of the body frame in the equilibrium state with respect to the Y-axis velocity, N p Represents the derivative of the moment of force on the Z-axis of the body frame in the equilibrium state with respect to the X-axis angular velocity, N r Represents the derivative of the moment of force on the Z-axis of the body frame in the equilibrium state with respect to the Z-axis angular velocity, N lat Represents the derivative of the moment of force on the Z-axis of the body frame in the equilibrium state with respect to the roll command, N ped Represents the derivative of the moment of force on the Z-axis of the body frame in the equilibrium state with respect to the yaw command, X uRepresents the derivative of the force acting on the X-axis of the aircraft system with respect to the X-axis velocity under the equilibrium state, X w Represents the derivative of the force acting on the X-axis of the aircraft system with respect to the Z-axis velocity under the equilibrium state, Z u Represents the derivative of the force acting on the Z-axis of the aircraft system with respect to the X-axis velocity under the equilibrium state, Z w Represents the derivative of the force acting on the Z-axis of the aircraft system with respect to the Z-axis velocity under the equilibrium state, M u Represents the derivative of the moment of force acting on the Y-axis of the aircraft system with respect to the X-axis velocity under the equilibrium state, M w Represents the derivative of the moment of force acting on the Y-axis of the aircraft system with respect to the Z-axis velocity under the equilibrium state, M q Represents the derivative of the moment of force acting on the Y-axis of the aircraft system with respect to the Y-axis angular velocity under the equilibrium state, X lon Represents the derivative of the force acting on the X-axis of the aircraft system with respect to the pitch command under the equilibrium state, X col Represents the derivative of the force acting on the X-axis of the aircraft system with respect to the vertical command under the equilibrium state, Z lon Represents the derivative of the force acting on the Z-axis of the aircraft system with respect to the pitch command under the equilibrium state, Z col Represents the derivative of the force acting on the Z-axis of the aircraft system with respect to the vertical command under the equilibrium state, M lon Represents the derivative of the moment of force acting on the Y-axis of the aircraft system with respect to the pitch command under the equilibrium state, M col Represents the derivative of the moment of force acting on the Y-axis of the aircraft system with respect to the vertical command under the equilibrium state

[0027] Among them, is the lateral subsystem, is the longitudinal subsystem, and the two can be independently controlled.

[0028] In a preferred embodiment, the inner loop control structure includes a dynamic inverse decoupler and an improved extended state observer, and the improved extended state observer is expressed as:

[0029]

[0030] Among them, is the i-th vector in the state quantity of the improved extended state observer, which is the estimated value of the corresponding vector in the state vector of the UAV state space system; is the estimated value of the system disturbance Δ; respectively represent the linear relationships between the state quantities of the i-th row of the state space matrix A and B of the UAV state space system and the input of the UAV state space system; G i and G i ' are the undetermined coefficients in the improved extended state observer; n is the dimension of the system state quantity, ε is a constant, and the superscript · represents the derivative of the parameter.

[0031] In a preferred embodiment, the control law of the dynamic inverse decoupler is expressed as:

[0032]

[0033] wherein, u in represents the control command output by the dynamic inverse decoupler, that is, the control command after disturbance compensation, C′ is the output matrix, represents the right inverse of the matrix.

[0034] In a preferred embodiment, the outer loop control structure adopts PID control.

[0035] The beneficial effects of the present invention include:

[0036] (1) Adding a tail pusher rotor makes the pitch angle always zero during forward flight, enabling the fuselage to be parallel to the horizontal plane while maintaining the fuselage movement, facilitating landing on the vehicle;

[0037] (2) Based on the extended observer control method, the rapidity of UAV control can be improved in the inner loop control, and the modeling inaccuracy can be eliminated. The robustness of the system can be further improved through the dynamic inverse decoupler. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Shows a top view structural schematic diagram of a vehicle-mounted tail pusher rotor UAV according to a preferred embodiment of the present invention; Figure 2 Shows a side view structural schematic diagram of a vehicle-mounted tail pusher rotor UAV according to a preferred embodiment of the present invention; Figure 3 Shows a schematic flow diagram of the control method of a vehicle-mounted tail pusher rotor UAV according to a preferred embodiment of the present invention; Figure 4 Shows the estimated response of the improved extended state observer to the roll angle in the presence of disturbance in Example 1; Figure 5 Shows the estimated response of the improved extended state observer to the roll angle rate in the presence of disturbance in Example 1; Figure 6 Shows the estimated response of the improved extended state observer to the pitch angle in the presence of disturbance in Example 1; Figure 7 Shows the estimated response of the improved extended state observer to the pitch angle rate in the presence of disturbance in Example 1; Figure 8 Shows the estimated response of the improved extended state observer to the yaw angle in the presence of disturbance in Example 1; Figure 9 Shows the estimated response of the improved extended state observer to the yaw angle rate in the presence of disturbance in Example 1; Figure 10 Shows the estimated total disturbance amount of the improved extended state observer to the roll channel in the presence of disturbance in Example 1; Figure 11 Shows the estimated total disturbance amount of the improved extended state observer to the pitch channel in the presence of disturbance in Example 1; Figure 12Illustrate the estimation of the total disturbance amount in the yaw channel by the improved extended state observer in the presence of disturbances in Embodiment 1; Figure 13 Illustrate the comparison chart of the response curves of the longitudinal speeds of Embodiment 1, Comparative Example 1, and Comparative Example 2; Figure 14 Illustrate the comparison chart of the step responses of the pitch channels of Embodiment 1, Comparative Example 1, and Comparative Example 2; Figure 15 Illustrate the comparison chart of the step responses of the vertical channels of Embodiment 1, Comparative Example 1, and Comparative Example 2; Figure 16 Illustrate the comparison chart of the step responses of the yaw channels of Embodiment 1, Comparative Example 1, and Comparative Example 2. Detailed implementation manners

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Through these descriptions, the features and advantages of the present invention will become clearer and more definite.

[0040] The special term "exemplary" here means "serving as an example, an embodiment, or illustrative". Any embodiment illustrated as "exemplary" here does not have to be construed as superior to or better than other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings do not have to be drawn to scale unless otherwise specified.

[0041] According to a vehicle-mounted tail-push rotor unmanned aerial vehicle provided by the present invention, as Figure 1 , 2 shown, a tail-push rotor is added to the tail of the rotor unmanned aerial vehicle. The tail-push rotor is located on the central vertical plane of the unmanned aerial vehicle, and the force generated by the tail-push rotor passes through the center of mass of the vehicle body and points to the due front of the unmanned aerial vehicle.

[0042] For the convenience of description, in the present invention, the four rotors in the top view of the unmanned aerial vehicle are numbered as main rotor 1, main rotor 2, main rotor 3, and main rotor 4 in a counterclockwise rotation order starting from the upper right corner. Among them, the rotors with odd numbers rotate counterclockwise, and the rotors with even numbers rotate clockwise.

[0043] According to the present invention, when the tail-push rotor unmanned aerial vehicle is in a hovering state, the rotational speeds of the four motors of the main rotors are the same, so the anti-torques generated by aerodynamics cancel each other out. The controller controls the vertical pulling force generated by the main propeller to be equal to its own gravity, and the tail-push rotor does not work and does not generate forward thrust. When the rotational speed of any group of motors changes, the attitude of the tail-push rotor unmanned aerial vehicle will change accordingly, thereby causing a change in position; and the pitch angle remains zero, and the forward flight movement is only controlled by the tail-push rotor.

[0044] The present invention also provides a control method for a vehicle-mounted tail-push rotor unmanned aerial vehicle, as Figure 3 shown, the method includes the following steps:

[0045] Establish a vehicle-mounted tail-push rotor unmanned aerial vehicle model;

[0046] According to the vehicle-mounted pusher-rotor UAV model, the UAV state-space system in the balanced state is obtained. The balanced state refers to the state of the UAV when the pitch angle of the UAV is zero. The obtained UAV state-space system includes a lateral subsystem and a longitudinal subsystem;

[0047] Based on the UAV state-space system, an inner-loop control structure is set to control the lateral subsystem, and an outer-loop control structure is set to control the longitudinal subsystem, so as to realize the control of the UAV's pose.

[0048] The vehicle-mounted pusher-rotor UAV model includes a control distribution sub-model, a blade dynamics sub-model, and a rigid-body dynamics sub-model of the pusher-rotor UAV.

[0049] The rigid-body dynamics sub-model of the pusher-rotor UAV is used to describe the attitude change of the vehicle-mounted pusher-rotor UAV under force, which is expressed as:

[0050]

[0051] Among them, u, v, and w are the projections of the UAV speed in the body coordinate system, p, q, and r are the projections of the UAV rotational angular velocity in the body coordinate system, F x 、F y 、F z are the projections of the forces generated by the rotors in the body coordinate system, L, M, and N are the projections of the torques generated by the rotors in the body coordinate system, T is the thrust of the pusher-rotor, D x 、D y 、D z are the projections of the aerodynamic drags received by the fuselage in the body coordinate system, is the projection of the aerodynamic moment received by the fuselage in the body coordinate system, is the inertia matrix of the UAV, Ω i (i = 1, 2, 3, 4) are the rotational speeds of the four rotor motors, I r represents the moment of inertia of a single rotor motor, and are the gyroscopic torques generated by the blade rotation, is the reaction torque generated when the blade accelerates or decelerates, g is the gravitational acceleration, m is the mass of the UAV, θ is the pitch angle of the UAV, ψ is the roll angle of the UAV, and φ is the yaw angle of the UAV.

[0052] The blade dynamics sub-model is used to describe the relationship between the rotational speeds of the rotor motors and the pusher motor and the forces and torques generated, which is expressed as:

[0053]

[0054] Among them, ρ represents the air density, Ω represents the rotational speed of the corresponding motor, R represents the radius of the rotor blade, C T represents the lift coefficient of the rotor, t b represents the lift generated by the rotor, C H represents the lateral force generated by the rotor, H p represents the lateral force generated by the rotor, C Q represents the anti-torque of the rotor, Q p represents the torque generated by the rotor, represents the pitch moment coefficient of the rotor, M yp represents the pitch moment generated by the rotor, represents the roll moment coefficient of the rotor, M xp represents the roll moment generated by the rotor.

[0055] Preferably, the lift T generated by the rotor b is set to:

[0056]

[0057] The lateral force H generated by the rotor p is set to:

[0058]

[0059] The torque Q generated by the rotor p is set to:

[0060]

[0061] The pitch moment M generated by the rotor yp is set to:

[0062]

[0063] The roll moment M generated by the rotor xp is set to:

[0064]

[0065] Among them, N represents the number of blades, c represents the blade chord length, a represents the change rate of the elemental lift coefficient, Θ represents the blade installation angle, α0 represents the zero-lift angle of attack, υ represents the horizontal advance ratio, μ represents the vertical advance ratio, represents the drag coefficient, which is a constant value, C m0 represents the zero-lift pitch moment coefficient, and b represents the change rate of the pitch moment coefficient.

[0066] The control allocation sub-model is used to allocate the UAV channel control instructions to the rotor motor and the tail thrust motor, and is expressed as:

[0067]

[0068] Among them, Ω1 represents the rotational speed of the main rotor 1 motor, Ω2 represents the rotational speed of the main rotor 2 motor, Ω3 represents the rotational speed of the main rotor 3 motor, Ω4 represents the rotational speed of the main rotor 4 motor, and Ω tail represents the rotational speed of the tail thrust motor, and R mixer represents the control allocation matrix, and δ lat represents the control command of the roll channel, and δ lon represents the control command of the pitch channel, and δ ped represents the control command of the yaw channel, and δ col represents the control command of the altitude channel, and δ tail represents the control command of the tail thrust throttle.

[0069] According to experience, the present invention gives a preferred control allocation matrix, which is expressed as:

[0070]

[0071] According to the present invention, in the balanced state, the vehicle-mounted tail thrust rotor UAV satisfies the following constraints:

[0072]

[0073] Among them, the parameter with a superscript "-" represents the parameter in the balanced state.

[0074] In the present invention, by setting the balanced state, the pitch angle of the UAV is always zero during forward flight, and the fuselage can be parallel to the horizontal plane while maintaining the movement of the fuselage, which is convenient for landing.

[0075] In the UAV state space system, the state vector x of the system is set as the motion state of the UAV, x = [u v w p q r φ θ ψ] T , and the input of the system is the control command u, u = [δ lat δ lon δ ped δ col δ tail T .

[0076] According to the constraints in the balanced state and the vehicle-mounted tail thrust rotor UAV model, the UAV state space system can be obtained, which is expressed as:

[0077]

[0078]

[0079] Among them, Y v represents the derivative of the force on the Y-axis of the body coordinate system with respect to the Y-axis velocity in the balanced state, ​Represents the X-axis velocity of the aircraft system in the equilibrium state, L v Represents the derivative of the X-axis moment of force of the aircraft system with respect to the Y-axis velocity in the equilibrium state, L p Represents the derivative of the X-axis moment of force of the aircraft system with respect to the X-axis angular velocity in the equilibrium state, L r Represents the derivative of the X-axis moment of force of the aircraft system with respect to the Z-axis angular velocity in the equilibrium state, L lat Represents the derivative of the X-axis moment of force of the aircraft system with respect to the roll command in the equilibrium state, L ped Represents the derivative of the X-axis moment of force of the aircraft system with respect to the yaw command in the equilibrium state, N v Represents the derivative of the Z-axis moment of force of the aircraft system with respect to the Y-axis velocity in the equilibrium state, N p Represents the derivative of the Z-axis moment of force of the aircraft system with respect to the X-axis angular velocity in the equilibrium state, N r Represents the derivative of the Z-axis moment of force of the aircraft system with respect to the Z-axis angular velocity in the equilibrium state, N lat Represents the derivative of the Z-axis moment of force of the aircraft system with respect to the roll command in the equilibrium state, N ped Represents the derivative of the Z-axis moment of force of the aircraft system with respect to the yaw command in the equilibrium state, X u Represents the derivative of the X-axis force of the aircraft system with respect to the X-axis velocity in the equilibrium state, X w Represents the derivative of the X-axis force of the aircraft system with respect to the Z-axis velocity in the equilibrium state, Z u Represents the derivative of the Z-axis force of the aircraft system with respect to the X-axis velocity Z in the equilibrium state w Represents the derivative of the Z-axis force of the aircraft system with respect to the Z-axis velocity in the equilibrium state, M u Represents the derivative of the Y-axis moment of force of the aircraft system with respect to the X-axis velocity in the equilibrium state, M w Represents the derivative of the Y-axis moment of force of the aircraft system with respect to the Z-axis velocity in the equilibrium state, M q Represents the derivative of the Y-axis moment of force of the aircraft system with respect to the Y-axis angular velocity in the equilibrium state, X lon Represents the derivative of the X-axis force of the aircraft system with respect to the pitch command in the equilibrium state, X col Represents the derivative of the X-axis force of the aircraft system with respect to the vertical command in the equilibrium state, Z lon Represents the derivative of the Z-axis force of the aircraft system with respect to the pitch command in the equilibrium state, Z col Represents the derivative of the Z-axis force of the aircraft system with respect to the vertical command in the equilibrium state, M lon Represents the derivative of the Y-axis moment of force of the aircraft system with respect to the pitch command in the equilibrium state, M col Represents the derivative of the Y-axis moment of force of the aircraft system with respect to the vertical command in the equilibrium state.

[0080] Among them, is the lateral subsystem, It is a longitudinal subsystem, and the two can be controlled independently.

[0081] The inner-loop control structure includes a dynamic decoupler and an improved extended state observer, and the improved extended state observer is expressed as:

[0082]

[0083] Where is the i-th vector in the state variables of the improved extended state observer, which is the estimated value of the corresponding vector in the state vector of the UAV state space system; is the estimated value of the system disturbance Δ; respectively represent the linear relationships between the state variables of the i-th row of the state space matrices A and B of the UAV state space system and the input of the UAV state space system; G i and G′ i are undetermined coefficients in the improved extended state observer; n is the dimension of the system state variables, ε is a constant, and the superscript · represents the derivative of the parameter.

[0084] Preferably, for the longitudinal subsystem, n = 4;

[0085] The state space of the UAV state space system is represented as:

[0086]

[0087]

[0088] Different from the traditional extended state observer, the improved extended state observer provided by the present invention greatly reduces the influence of system disturbance on the classical dynamic inversion, making the decoupled system more robust. Specifically, it can be proved by the following method:

[0089] If the matrix E defined as the following formula is a Hurwitz matrix and satisfies the assumption of the existence of the error derivative, then for each positive constant a, when t ∈ [a, ∞), there is where the matrix E is

[0090]

[0091] Then, as long as the undetermined coefficients G i and G i ′ in the extended state observer are large enough, the extended state observer can achieve accurate estimation of the state variables and disturbances of the dynamic model. The estimated value of the state variables is used for the design of the subsequent dynamic decoupler, and the estimated value of the disturbance is used to compensate the system input according to the idea of ADRC. The compensated control command u in is

[0092]

[0093] Among them is the right inverse of matrix B. Combining with the UAV state space system, we have

[0094]

[0095] When the estimated value of the disturbance approaches the actual value Δ, the above formula degenerates into the undisturbed model, so that the decoupler can be designed according to this undisturbed model. Therefore, the existence of the extended state observer greatly reduces the influence of system disturbances on the classical dynamic inversion.

[0096] The control law of the dynamic inversion decoupler is expressed as:

[0097]

[0098] where u in represents the control command output by the dynamic inversion decoupler, that is, the control command after disturbance compensation. C′ is the output matrix, represents the right inverse of the matrix.

[0099] Preferably, for the lateral subsystem, the output matrix C′ is:

[0100]

[0101] For the longitudinal subsystem, the output matrix C′ is

[0102]

[0103] In the dynamic inversion decoupler of the present invention, it is optimized for vehicle-mounted pusher-rotor UAVs. When in the longitudinal subsystem, the pitch angle and z-axis speed are selected as the desired input commands, and when in the lateral subsystem, the roll angle and yaw angle are selected as the desired input commands.

[0104] The outer loop control structure adopts PID control, and its transfer function G c (s) is set as:

[0105]

[0106] where K P is the proportional link gain coefficient, K I is the integral link gain coefficient, K D is the differential link gain coefficient, and s is the transfer parameter.

[0107] It should be understood that various forms of the processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired results of the technical solution disclosed in this invention can be achieved, and no limitation is imposed herein.

[0108] Embodiment

[0109] Embodiment 1

[0110] A simulation test is conducted on an in-vehicle pusher-rotor UAV. The in-vehicle pusher-rotor UAV is as Figure 1 shown. During the test, according to the in-vehicle pusher-rotor UAV model, the UAV state space system in the equilibrium state is obtained. The equilibrium state refers to the state of the UAV when the pitch angle of the UAV is zero. The obtained UAV state space system includes a lateral subsystem and a longitudinal subsystem;

[0111] Based on the UAV state space system, an inner-loop control structure is set to control the lateral subsystem, and an outer-loop control structure is set to control the longitudinal subsystem, thereby realizing the control of the UAV's pose.

[0112] Among them, the in-vehicle pusher-rotor UAV model is set as:

[0113]

[0114]

[0115]

[0116] Among them, the in-vehicle pusher-rotor UAV satisfies the following constraints:

[0117]

[0118] The in-vehicle pusher-rotor UAV state space system is set as:

[0119]

[0120]

[0121] The inner-loop control structure includes a dynamic decoupler and an improved extended state observer, and the improved extended state observer is expressed as:

[0122]

[0123] The control law of the dynamic decoupler is expressed as:

[0124]

[0125] Among them, for the lateral subsystem, the output matrix C' is:

[0126]

[0127] For the longitudinal subsystem, the output matrix C' is

[0128]

[0129] The outer loop control structure adopts PID control, and its transfer function G c (s) is set as:

[0130]

[0131] During the simulation process, disturbances are simultaneously added to the three attitude channels at 5 s, and the state estimation effect is observed. The effect is as Figures 4 - 12 shown, where Figure 4 shows the response estimation of the improved extended state observer for the roll angle in the presence of disturbances, Figure 5 shows the response estimation of the improved extended state observer for the roll angle rate in the presence of disturbances, Figure 6 shows the response estimation of the improved extended state observer for the pitch angle in the presence of disturbances, Figure 7 shows the response estimation of the improved extended state observer for the pitch angle rate in the presence of disturbances, Figure 8 shows the response estimation of the improved extended state observer for the yaw angle in the presence of disturbances, Figure 9 shows the response estimation of the improved extended state observer for the yaw angle rate in the presence of disturbances, Figure 10 shows the total disturbance amount estimation of the improved extended state observer for the roll channel in the presence of disturbances, Figure 11 shows the total disturbance amount estimation of the improved extended state observer for the pitch channel in the presence of disturbances, Figure 12 shows the total disturbance amount estimation of the improved extended state observer for the yaw channel in the presence of disturbances. It can be seen from the figure that in the presence of disturbances, the improved extended state observer can achieve fast and effective estimation of the disturbance value, and the estimation has no static error.

[0132] During the simulation process, to simulate the external disturbances such as gusts that the UAV may encounter during actual flight, as well as the uncertainties of the model itself, a disturbance of Δ i = 5sin(t) + WGN, i = 1, 2, 3, 4 is applied, where WGN represents Gaussian white noise. The simulation time is set to 20 s, the step size is set to 0.01 s, and a step-form desired pitch angle signal starting at 1 s is applied to the UAV in the longitudinal subsystem.

[0133] During the simulation process, unit step desired signals starting at 1 s were also applied to the pitch, vertical, and yaw channels respectively.

[0134] Comparative Example 1

[0135] The same experiment as in Example 1 was conducted, except that a Luenberger observer was used to replace the improved extended state observer.

[0136] Comparative Example 2

[0137] The same experiment as in Example 1 was conducted, except that a cascade PID was used to replace the dynamic inverse decoupler and the improved extended state observer.

[0138] Comparing the response curves of the longitudinal velocity w output by the longitudinal channel after applying a step-form desired pitch angle signal starting at 1 s to the UAV in the longitudinal subsystem in Example 1, Comparative Example 1, and Comparative Example 2, the results are as Figure 13 shown. It can be seen from the figure that: for the method in Comparative Example 2, at the instant of applying the step signal, the longitudinal velocity changes suddenly, and over time, due to the completely open-loop reason, the response gradually diverges; for the method in Comparative Example 1, since dynamic inversion is used for decoupling, the response vibrates sinusoidally at the same frequency as the given sinusoidal error signal and does not diverge. However, due to the reason of not considering interference, its vibration amplitude is still large and does not meet the decoupling effect; while for the method in Example 1, it is ensured that the response fluctuates slightly around 0 all the time, indicating that its decoupling effect is the best.

[0139] Comparing the step responses of different channels after applying unit step desired signals starting at 1 s to the pitch, vertical, and yaw channels in Example 1, Comparative Example 1, and Comparative Example 2, where Figure 14 shows the step response of the pitch channel, Figure 15 shows the step response of the vertical channel, Figure 16 shows the step response of the yaw channel. It can be seen from the figure that the step responses obtained by the methods in Comparative Example 1 and Comparative Example 2 vibrate sinusoidally at the same frequency as the given sinusoidal error signal, while the step response obtained by the method in Example 1 can reach a steady state completely within 2 s.

[0140] The present invention has been described above in combination with preferred embodiments. However, these embodiments are only exemplary and only serve an illustrative purpose. On this basis, various substitutions and improvements can be made to the present invention, and these all fall within the protection scope of the present invention.

Claims

1. An on-vehicle tail-push rotor unmanned aerial vehicle, characterized in that, Add a pusher rotor to the tail of the rotary-wing UAV. The pusher rotor is located on the central vertical plane of the UAV, and the force generated by the pusher rotor passes through the centroid of the airframe and points directly in front of the UAV.

2. A control method for an in-vehicle tail-push rotor unmanned aerial vehicle, characterized in that The method includes the following steps: Establish a vehicle-mounted pusher-rotor UAV model; According to the vehicle-mounted pusher-rotor UAV model, obtain the UAV state-space system in the equilibrium state. The equilibrium state refers to the state of the UAV when the pitch angle of the UAV is zero. The obtained UAV state-space system includes a lateral subsystem and a longitudinal subsystem; Based on the UAV state-space system, set an inner-loop control structure to control the lateral subsystem, and set an outer-loop control structure to control the longitudinal subsystem, so as to realize the control of the UAV's pose.

3. The control method of the vehicle-mounted pusher-rotor UAV according to claim 2, wherein The vehicle-mounted pusher-rotor UAV model includes a control allocation sub-model, a blade dynamics sub-model, and a rigid-body dynamics sub-model of the pusher-rotor UAV; The vehicle-mounted pusher-rotor UAV model includes a control allocation sub-model, a blade dynamics sub-model, and a rigid-body dynamics sub-model of the pusher-rotor UAV, The blade dynamics sub-model is used to describe the relationship between the rotational speeds of the rotor motor and the pusher motor and the generated forces and torques, The control allocation sub-model is used to allocate the UAV channel control commands to the rotor motor and the pusher motor.

4. The control method of the vehicle-mounted pusher-rotor UAV according to claim 3, wherein The rigid-body dynamics sub-model of the pusher-rotor UAV is expressed as: Among them, u, v, and w are the projections of the UAV velocity in the body coordinate system, p, q, and r are the projections of the UAV rotational angular velocity in the body coordinate system, F x , F y , F z are the projections of the forces generated by the rotors in the body coordinate system, L, M, and N are the projections of the torques generated by the rotors in the body coordinate system, T is the thrust of the tail rotor, D x , D y , D z are the projections of the aerodynamic drags on the fuselage in the body coordinate system, is the aerodynamic torque on the fuselage in the body coordinate system, is the inertia matrix of the UAV, Ω i (i = 1, 2, 3, 4) are the rotational speeds of the four rotor motors, I r represents the moment of inertia of a single rotor motor, and are the gyroscopic torques generated by the rotation of the blades, is the reaction torque generated when the blades are accelerating or decelerating, g is the acceleration due to gravity, m is the mass of the UAV, θ is the pitch angle of the UAV, ψ is the roll angle of the UAV, and φ is the yaw angle of the UAV.

5. The control method of the vehicle-mounted pusher-rotor UAV according to claim 3, wherein The blade dynamics sub-model is expressed as: Among them, ρ represents the air density, Ω represents the rotational speed of the corresponding motor, R represents the radius of the rotor blade, C T represents the lift coefficient of the rotor, T b represents the lift generated by the rotor, C H represents the lateral force generated by the rotor, H p represents the lateral force generated by the rotor, C Q represents the anti-torque of the rotor, Q p represents the torque generated by the rotor, represents the pitch moment coefficient of the rotor, M yp represents the pitch moment generated by the rotor, represents the roll moment coefficient of the rotor, M xp represents the roll moment generated by the rotor.

6. The control method of the vehicle-mounted pusher-rotor UAV according to claim 3, wherein The control allocation sub-model is expressed as: Among them, Ω1 represents the rotational speed of the main rotor 1 motor, Ω2 represents the rotational speed of the main rotor 2 motor, Ω3 represents the rotational speed of the main rotor 3 motor, Ω4 represents the rotational speed of the main rotor 4 motor, and Ω tail represents the rotational speed of the tail thrust motor, and R mixer represents the control allocation matrix, and δ lat represents the control command for the roll channel, and δ lon represents the control command for the pitch channel, and δ ped represents the control command for the yaw channel, and δ col represents the control command for the altitude channel, and δ tail represents the control command for the tail thrust throttle.

7. The control method of the vehicle-mounted pusher-rotor UAV according to claim 2, wherein Obtain the UAV state-space system, expressed as: Among them, Y v represents the derivative of the force acting on the Y-axis of the aircraft system with respect to the Y-axis velocity in the equilibrium state, represents the X-axis velocity of the aircraft system in the equilibrium state, L v represents the derivative of the moment of force acting on the x-axis of the aircraft system with respect to the Y-axis velocity in the equilibrium state, L p represents the derivative of the moment of force acting on the X-axis of the aircraft system with respect to the X-axis angular velocity in the equilibrium state, L r represents the derivative of the moment of force acting on the X-axis of the aircraft system with respect to the Z-axis angular velocity in the equilibrium state, L lat represents the derivative of the moment of force acting on the X-axis of the aircraft system with respect to the roll command in the equilibrium state, L ped represents the derivative of the moment of force acting on the X-axis of the aircraft system with respect to the yaw command in the equilibrium state, N v represents the derivative of the moment of force acting on the Z-axis of the aircraft system with respect to the Y-axis velocity in the equilibrium state, N p represents the derivative of the moment of force acting on the Z-axis of the aircraft system with respect to the X-axis angular velocity in the equilibrium state, N r represents the derivative of the moment of force acting on the Z-axis of the aircraft system with respect to the Z-axis angular velocity in the equilibrium state, N lat represents the derivative of the moment of force acting on the Z-axis of the aircraft system with respect to the roll command in the equilibrium state, N ped represents the derivative of the moment of force acting on the Z-axis of the aircraft system with respect to the yaw command in the equilibrium state, X u represents the derivative of the force acting on the X-axis of the aircraft system with respect to the X-axis velocity in the equilibrium state, X w represents the derivative of the force acting on the X-axis of the aircraft system with respect to the Z-axis velocity in the equilibrium state, Z u represents the derivative of the force acting on the Z-axis of the aircraft system with respect to the X-axis velocity Z in the equilibrium state w represents the derivative of the force acting on the Z-axis of the aircraft system with respect to the Z-axis velocity in the equilibrium state, M u represents the derivative of the moment of force acting on the Y-axis of the aircraft system with respect to the X-axis velocity in the equilibrium state, M w represents the derivative of the moment of force acting on the Y-axis of the aircraft system with respect to the Z-axis velocity in the equilibrium state, M q represents the derivative of the moment of force acting on the Y-axis of the aircraft system with respect to the Y-axis angular velocity in the equilibrium state, X lon represents the derivative of the force acting on the X-axis of the aircraft system with respect to the pitch command in the equilibrium state, X col represents the derivative of the force acting on the X-axis of the aircraft system with respect to the vertical command in the equilibrium state, Z lon represents the derivative of the force acting on the Z-axis of the aircraft system with respect to the pitch command in the equilibrium state, Z col represents the derivative of the force acting on the Z-axis of the aircraft system with respect to the vertical command in the equilibrium state, M lon represents the derivative of the moment of force acting on the Y-axis of the aircraft system with respect to the pitch command in the equilibrium state, M col represents the derivative of the moment of force acting on the Y-axis of the aircraft system with respect to the vertical command in the equilibrium state Among them, is the horizontal subsystem, is the vertical subsystem, and the two can be controlled independently.

8. The control method of the vehicle-mounted pusher-rotor UAV according to claim 2, wherein The inner-loop control structure includes a dynamic inverse decoupler and an improved extended state observer. The improved extended state observer is expressed as: Among them, is the i-th vector in the state variables of the improved extended state observer, which is the estimated value of the corresponding vector in the state vector of the UAV state space system; is the estimated value of the system disturbance Δ; respectively represent the linear relationships between the state variables of the i-th row of the state space matrices A and B of the UAV state space system and the input of the UAV state space system; G i and G′ i are the undetermined coefficients in the improved extended state observer; n is the dimension of the system state variables, ε is a constant, and the superscript · represents the derivative of the parameter.

9. The control method of the vehicle-mounted pusher-rotor UAV according to claim 8, wherein The control law of the dynamic inverse decoupler is expressed as: where, u in represents the control command output by the dynamic inverse decoupler, that is, the control command after disturbance compensation, C′ is the output matrix, represents the right inverse of the matrix.

10. The control method of the vehicle-mounted pusher-rotor UAV according to claim 2, wherein The outer-loop control structure adopts PID control.

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