A tilt-rotor tri-rotor UAV control distribution method and device

Abstract

The present application relates to a control allocation method and device for a tilt-rotor three-rotor UAV. The method includes: constructing a control allocation model for the tilt-rotor UAV based on virtual thrust, virtual control torque, and actuator control instructions; solving the control allocation model for the tilt-rotor UAV using a decoupling control allocation method, iterating the solution process step by step to obtain a relationship matrix between the tilt angle, rotor speed, and the control allocation matrix; simplifying the control allocation matrix using the reference tilt angle characteristic under the rotor mode, analyzing the control allocation matrix, and obtaining perturbation parameters; collecting virtual control quantities in a stable hovering state, correcting the tension constant and center of gravity position parameters based on the virtual control quantities, correcting the control allocation matrix using accurate control allocation parameters, and solving the relationship matrix based on the corrected control allocation matrix to obtain the rotor speed. This method can improve the control allocation accuracy and robustness.

Description

Technical Field

[0001] The present application relates to the field of flight control technology for three-rotor UAVs, and in particular to a control distribution method and device for a tilt-rotor three-rotor UAV. Background Art

[0002] To combine the advantages of vertical takeoff and landing (VTOL) and maneuverability of rotary-wing drones with the long endurance and high speed of fixed-wing drones, researchers have begun exploring different types of vertical takeoff and landing (VTOL) fixed-wing drones, primarily tail-seat drones, compound-wing drones, tilt-rotor drones, and tilt-wing drones. The tilt-tri-rotor drone is a typical example of this type of drone. By reusing its power system, it possesses the capabilities of vertical takeoff and landing, high-speed cruising, and long-endurance, long-range flight. The control system of a tilt-tri-rotor drone can be divided into an upper-level controller and a lower-level control distributor. The control distributor converts the virtual control torque output by the upper-level controller into a control variable for the lower-level actuator, causing the actuator to generate force or torque as desired by the controller, achieving closed-loop attitude and altitude control. The system parameters of a tilt-tri-rotor drone are typically obtained through static identification tests. Due to the complex structure and aerodynamic disturbances of the tilt-tri-rotor drone, there is a certain difference between the statically measured system parameters and the parameters during actual dynamic flight, which in turn affects the accuracy of the control distribution and reduces flight control performance. Summary of the Invention

[0003] Based on this, it is necessary to provide a tilt-rotor three-rotor UAV control allocation method and device that can improve the control allocation accuracy and robustness to address the above technical problems.

[0004] A tilt-rotor tri-rotor UAV control allocation method, the method comprising:

[0005] Obtain virtual control quantities and actuator control instructions for the tilt-rotor tri-rotor UAV; the virtual control quantities include virtual thrust and virtual control torque;

[0006] A control distribution model for a tiltrotor UAV is constructed based on virtual thrust, virtual control torque, and actuator control instructions;

[0007] The decoupling control allocation method is used to solve the control allocation model of the tilt-rotor UAV. The solution process is iteratively performed step by step to obtain the relationship matrix between the tilt angle, rotor speed and the control allocation matrix.

[0008] The factors affecting the control allocation accuracy are analyzed based on the decoupling control allocation method. The control allocation matrix is ​​simplified using the reference tilt angle characteristics under the rotor mode. The control allocation matrix is ​​analyzed to obtain the perturbation parameters; the perturbation parameters include the tension constant and the center of gravity position parameters.

[0009] Collect virtual control quantities in a stable hovering state, and modify the tension constant and center of gravity position parameters based on the virtual control quantities to obtain accurate control distribution parameters;

[0010] The control allocation matrix is ​​corrected using accurate control allocation parameters, and the relationship matrix between the rotor speed and the control allocation matrix is ​​solved according to the corrected control allocation matrix to obtain the rotor speed.

[0011] In one embodiment, a control allocation model for a tilt-rotor UAV is constructed based on virtual thrust, virtual control torque, and actuator control instructions, including:

[0012] The control distribution model of the tilt-rotor UAV is constructed based on the virtual thrust, virtual control torque and actuator control instructions:

[0013]

[0014] Among them, {Γ x , Γ y , Γ z} represents the virtual control torque, T represents the virtual thrust, {ω1, ω2, ω3} represents the three rotor speeds of the actuator, {α1, α2, α3} represents the three tilt angles of the actuator, c * represents cos(*), s * represents sin(*),ω i With α i denote the rotation speed and tilt angle of rotor i, respectively, (r ix , r iy ) is the position of rotor i relative to the center of gravity, k f 、k d They represent the thrust constant and torque coefficient of the rotor respectively.

[0015] In one embodiment, a decoupled control allocation method is used to solve a control allocation model for a tilt-rotor UAV. The solution process is iteratively performed step by step to successively calculate the tilt angle and the rotor speed, including:

[0016] The decoupling control allocation method is used to solve the control allocation model of the tilt-rotor UAV. The reference proportional control is introduced in the solution process to construct the relationship matrix between the tilt angle and the virtual heading control torque.

[0017] Roll, pitch and altitude control are performed by adjusting the rotor speed, and a relationship matrix between the rotor speed and the control allocation matrix is ​​constructed;

[0018] The relationship matrix between the tilt angle and the virtual heading control torque is solved to obtain the tilt angle.

[0019] In one embodiment, a reference proportional control is introduced in the solution process to construct a relationship matrix between the tilt angle and the virtual heading control torque, including:

[0020] In the solution process, the reference proportional control is introduced to construct the relationship matrix between the tilt angle and the virtual heading control torque:

[0021]

[0022] Where α represents the reference tilt angle related to the flight mode, δ is a positive constant, and Γ z Indicates the virtual heading control torque.

[0023] In one embodiment, the roll, pitch, and altitude control are performed by adjusting the rotor speed, and a relationship matrix between the rotor speed and the control allocation matrix is ​​constructed, including:

[0024] By adjusting the rotor speed to perform roll, pitch and altitude control, the relationship matrix between the rotor speed and the control allocation matrix is ​​constructed as follows:

[0025]

[0026] Among them, Γ x represents the virtual roll control torque, Γ y represents the virtual pitch control torque, {ω1, ω2, ω3} represents the three rotor speeds of the actuator, and H -1 represents the inverse matrix of the control allocation matrix

[0027] In one embodiment, the control allocation matrix is ​​simplified by using the reference tilt angle characteristic in the rotor mode, including:

[0028] The control allocation matrix is ​​simplified by using the reference tilt angle characteristics under the rotor mode:

[0029]

[0030] Among them, k f represents the thrust constant of the rotor, r represents the distance between the front and rear rotors, 0<ε<1 is the center of gravity position parameter, and εr represents the longitudinal distance of the front rotor relative to the center of gravity.

[0031] In one embodiment, the virtual control variable includes a virtual pitch control torque in a stable hovering state; and the tension constant and the center of gravity position parameter are corrected according to the virtual control variable to obtain accurate control distribution parameters, including:

[0032] According to the virtual pitch control torque in the stable hovering state, the tension constant and the center of gravity position parameters are corrected to obtain the accurate control distribution parameters:

[0033]

[0034] Where G represents the gravity of the aircraft, k′ f , ε′ respectively represent the measured values ​​of the rotor thrust constant and the center of gravity position parameter, Γ y represents the virtual pitch control torque in the stable hovering state, T represents the virtual thrust, and r represents the distance parameter.

[0035] A tilt-rotor tri-rotor UAV control distribution device, the device comprising:

[0036] A data acquisition module is used to obtain virtual control quantities and actuator control instructions of the tilt-rotor tri-rotor UAV; the virtual control quantities include virtual thrust and virtual control torque;

[0037] A control allocation model building module is used to build a control allocation model of the tilt-rotor UAV based on the virtual thrust and virtual control torque and actuator control instructions;

[0038] The tilt angle solving module is used to solve the control allocation model of the tilt-rotor UAV using the decoupling control allocation method. The solution process is iteratively performed step by step to obtain the relationship matrix between the tilt angle, rotor speed and the control allocation matrix;

[0039] The control allocation accuracy influencing factor analysis module is used to analyze the factors affecting the control allocation accuracy based on the decoupled control allocation method. The control allocation matrix is ​​simplified by using the reference tilt angle characteristics under the rotor mode. The control allocation matrix is ​​analyzed to obtain the perturbation parameters; the perturbation parameters include the tension constant and the center of gravity position parameter.

[0040] The perturbation parameter correction module is used to collect virtual control quantities in a stable hovering state, and to correct the tension constant and center of gravity position parameters according to the virtual control quantities to obtain accurate control distribution parameters;

[0041] The rotor speed solving module is used to correct the control allocation matrix using accurate control allocation parameters, and solve the relationship matrix between the rotor speed and the control allocation matrix according to the corrected control allocation matrix to obtain the rotor speed.

[0042] The control allocation method and device for a tilt-trirotor UAV first establishes a control allocation model based on the UAV's structural characteristics; then designs a control allocation algorithm to decouple heading from other channels; further, combining the control allocation model and algorithm, analyzes parameter perturbations in the control allocation; and finally, designs a control allocation correction method based on the perturbed parameters to improve control allocation robustness and efficiency, reduce allocation errors, and enhance allocation accuracy. Compared to existing control allocation methods, this invention further analyzes the sources of allocation errors and provides improvement methods, which helps improve control allocation robustness and flight control performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 1 is a flow chart of a control allocation method for a tilt-rotor tri-rotor UAV according to an embodiment;

[0044] Figure 2 A schematic diagram of a tilt-rotor tri-rotor UAV model in one embodiment;

[0045] Figure 3 The simulation results of the control distribution of a tilt-rotor tri-rotor UAV in one embodiment are shown;

[0046] Figure 4 The figure is a schematic diagram of a control distribution device for a tilt-rotor tri-rotor UAV in one embodiment. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0048] In one embodiment, Figure 1 As shown, a control allocation method for a tilt-rotor tri-rotor UAV is provided, comprising the following steps:

[0049] Step 102: Acquire virtual control variables and actuator control instructions of the tilt-rotor tri-rotor UAV; the virtual control variables include virtual thrust and virtual control torque; and construct a control allocation model for the tilt-rotor UAV based on the virtual thrust, virtual control torque, and actuator control instructions.

[0050] Tilt-rotor drones such as Figure 2 As shown, the tilt-rotor tri-rotor UAV adopts a dual-tail-strut, three-point design. Its actuators include three rotor power subsystems, three tilt servo subsystems, elevators, ailerons, and rudders, resulting in three flight modes. This paper primarily addresses the issue of efficient and robust control allocation within the rotor mode. In rotor mode, attitude control is achieved by adjusting rotor speed and tilt angle. Roll motion is achieved through differential control of left and right rotor speeds, pitch motion through differential control of front and rear rotor speeds, and yaw motion based on differential tilt angles. Altitude control is achieved by synchronously adjusting the speeds of all three rotors.

[0051] There are four virtual control quantities in the rotor control mechanism, namely the virtual thrust T output by the altitude controller, the virtual control torque {Γ x , Γ y , Γ z}, the actuator has three speeds {ω1, ω2, ω3} and three tilt angles {α1, α2, α3}. The goal of control allocation is to allocate the virtual control quantity {Γx , Γ y , Γ z , T} solves the actuator control instructions {ω1, ω2, ω3} and {α1, α2, α3}.

[0052] The tilt angle is defined as zero when the rotor is pointing vertically upward and negative when tilted forward. The tilt angles of the three rotors can be expressed as α1 = α + Δα, α2 = α - Δα, and α3 = α, respectively, where α is the reference tilt angle and Δα represents the differential angle used for heading control. The control allocation problem for a tilt-rotor UAV can be expressed as:

[0053]

[0054] Among them, c * represents cos(*), s * represents sin(*),ω i With α i denote the rotation speed and tilt angle of rotor i, respectively, (r ix , r iy ) is the position of rotor i relative to the center of gravity, k f 、k d are the thrust coefficient and torque coefficient of the rotor respectively.

[0055] Step 104 , using a decoupled control allocation method to solve the control allocation model of the tilt-rotor UAV, iterating the solution process step by step to obtain a relationship matrix between the tilt angle, the rotor speed, and the control allocation matrix.

[0056] Based on the control distribution model, since the response characteristics of the motor and the tilt servo are very different, and the heading control is achieved based on the differential adjustment of the tilt angle, this application designs a decoupling control distribution method. The basic idea is to iteratively solve the problem step by step. First, the tilt angle {α1, α2, α3} is calculated, and then the rotor speed {ω1, ω2, ω3} is calculated.

[0057] The heading adjustment is achieved by differential control of the rotor tilt angle. The tilt angle is related to the virtual heading control torque Γ z Related, introducing proportional control, the tilt angle is:

[0058]

[0059] Where α represents the reference tilt angle, which is related to the flight mode and has a value range of [-π / 2, 0]. In rotor mode, α = 0. δ is a positive constant that has a direct impact on the heading control effect and is adjusted according to the actual situation during flight. Roll, pitch, and altitude control are achieved by adjusting the rotor speed. Based on the distribution model and tilt angle, we have:

[0060]

[0061]

[0062] Among them, the control allocation matrix H∈R 3×3 The tensile force constant k in f and torque constant k d The coordinate position (r ix , r iy ) can be obtained based on actual measurement of the center of gravity. The tilt servo has high control accuracy. The tilt angles {α1, α2, α3} have been obtained in the above calculation process, so the rotor speed is:

[0063]

[0064] The control allocation algorithm described above solves the control allocation problem for tilt-rotor tri-rotor UAVs. Its solution is simple and easy to apply in engineering applications. However, it requires high precision in the allocation matrix. Inaccurate parameters can result in large allocation errors, degrading flight control performance and even compromising flight safety.

[0065] Step 106 , analyzing factors influencing control allocation accuracy according to the decoupled control allocation method, simplifying the control allocation matrix using the reference tilt angle characteristic under the rotor mode, analyzing the control allocation matrix, and obtaining perturbation parameters; the perturbation parameters include the tension constant and the center of gravity position parameter.

[0066] According to the control allocation algorithm, we further analyze the specific factors that affect the control allocation accuracy. For the rotor power system, the torque constant k d Much smaller than the tensile constant k f , and the reference tilt angle α in the rotor mode is 0, and the tilt angles α1 and α2 are very small, then the control allocation matrix H can be simplified to:

[0067]

[0068] Where r represents the distance between the front and rear rotors, 0<ε<1 is the center of gravity position parameter, the longitudinal distance of the front rotor relative to the center of gravity is expressed as εr, and the longitudinal distance of the tail rotor relative to the center of gravity is r(1-ε). This application further analyzes and finds that the uncertainty in the control allocation matrix mainly comes from the tension constant and the center of gravity position parameter, that is, the parameter k f There is an error between the measured value of ε and the true value in dynamic flight.

[0069] Step 108 : collecting virtual control quantities in a stable hovering state, and correcting the tension constant and the center of gravity position parameters according to the virtual control quantities to obtain accurate control distribution parameters.

[0070] Step 110 , using accurate control allocation parameters to correct the control allocation matrix, and solving the relationship matrix between the rotor speed and the control allocation matrix based on the corrected control allocation matrix to obtain the rotor speed.

[0071] For the two perturbation parameters, if the control allocation parameters are accurate, in the absence of external interference and the condition of stable hovering of the aircraft, the virtual control torque is zero, and the virtual control thrust T is equal to the aircraft gravity G. When the aircraft is in a stable hovering state, the actual rotor speed and tilt angle remain basically unchanged. This fact is not affected by the accuracy of the control allocation and is only related to the power configuration and aircraft structure. From the control allocation matrix, it can be seen that when the rotor speed and tilt angle are constant, the thrust constant k f Too large will directly lead to the virtual thrust T and virtual pitch control torque Γ y Increase. A large parameter ε will result in a virtual pitch control torque Γ during hovering. y Increase. In summary, the perturbation of control allocation parameters mainly affects pitch and altitude control, and causes the virtual control amount to deviate from the theoretical value. Combined with the above analysis, the virtual control amount {Γ y ,T} design correction method to improve the robustness of control allocation and lay the foundation for attitude control. Assume that the control allocation parameters are all accurate values ​​k f , ε, then the control allocation error is zero. In the stable hovering state, the virtual control torque is equal to the actual torque, that is, Γ y =0, T=G, combined with the control allocation model, the following equation holds:

[0072]

[0073] Assume that the control allocation parameters are all measured values ​​k′ f , ε′, then there is an error in the control allocation. In the stable hovering state, the virtual control quantity Γ output by the controller is y ≠0, T≠G, we can deduce:

[0074]

[0075] where k′ f , ε′ represent the measured values ​​of tension constant and center of gravity position parameter, respectively, {Γ y , T} is the virtual control variable in the stable hovering state, and G represents the aircraft gravity. The rotor speed and tilt angle in the stable hovering state are considered as unknown constants. Combining the above two equations, the control allocation parameters satisfy:

[0076]

[0077] The core idea of ​​the control allocation parameter correction method is to collect virtual control quantities {Γ y, T}, and then the above formula is used to perform offline calculation to obtain accurate control allocation parameters.

[0078] According to the modified control allocation matrix, the relationship matrix between the rotor speed and the control allocation matrix is ​​solved to obtain the rotor speed. The goal of the control allocation is to calculate the virtual control quantity {Γ x , Γ y , Γ z , T} solves the actuator control instructions {ω1, ω2, ω3} and {α1, α2, α3}, achieving efficient and robust control allocation effect.

[0079] In the aforementioned control allocation method for a tilt-trirotor UAV, a control allocation model is first established based on the UAV's structural characteristics. A control allocation algorithm is then designed to decouple heading from other channels. Furthermore, the control allocation model and algorithm are combined to analyze parameter perturbations in the control allocation. Finally, a control allocation correction method is designed based on the perturbed parameters to improve the robustness and efficiency of the control allocation, reduce allocation errors, and enhance allocation accuracy. Compared to existing control allocation methods, this method further analyzes the sources of allocation errors and provides improvement methods, which helps improve control allocation robustness and flight control performance.

[0080] In one embodiment, a control allocation model for a tilt-rotor UAV is constructed based on virtual thrust, virtual control torque, and actuator control instructions, including:

[0081] The control distribution model of the tilt-rotor UAV is constructed based on the virtual thrust, virtual control torque and actuator control instructions:

[0082]

[0083] Among them, {Γ x , Γ y , Γ z} represents the virtual control torque, T represents the virtual thrust, {ω1, ω2, ω3} represents the three rotor speeds of the actuator, {α1, α2, α3} represents the three tilt angles of the actuator, c * represents cos(*), s * represents sin(*),ω i With α i denote the rotation speed and tilt angle of rotor i, respectively, (r ix , r iy ) is the position of rotor i relative to the center of gravity, k f 、k d They represent the thrust constant and torque coefficient of the rotor respectively.

[0084] In one embodiment, a decoupled control allocation method is used to solve a control allocation model for a tilt-rotor UAV. The solution process is iteratively performed step by step to successively calculate the tilt angle and the rotor speed, including:

[0085] The decoupling control allocation method is used to solve the control allocation model of the tilt-rotor UAV. The reference proportional control is introduced in the solution process to construct the relationship matrix between the tilt angle and the virtual heading control torque.

[0086] Roll, pitch and altitude control are performed by adjusting the rotor speed, and a relationship matrix between the rotor speed and the control allocation matrix is ​​constructed;

[0087] The relationship matrix between the tilt angle and the virtual heading control torque is solved to obtain the tilt angle.

[0088] In one embodiment, a reference proportional control is introduced in the solution process to construct a relationship matrix between the tilt angle and the virtual heading control torque, including:

[0089] In the solution process, the reference proportional control is introduced to construct the relationship matrix between the tilt angle and the virtual heading control torque:

[0090]

[0091] Where α represents the reference tilt angle related to the flight mode, δ is a positive constant, and Γ z Indicates the virtual heading control torque.

[0092] In one embodiment, the roll, pitch, and altitude control are performed by adjusting the rotor speed, and a relationship matrix between the rotor speed and the control allocation matrix is ​​constructed, including:

[0093] By adjusting the rotor speed to perform roll, pitch and altitude control, the relationship matrix between the rotor speed and the control allocation matrix is ​​constructed as follows:

[0094]

[0095] Among them, Γ x represents the virtual roll control torque, Γ y represents the virtual pitch control torque, {ω1, ω2, ω3} represents the three rotor speeds of the actuator, and H -1 represents the inverse matrix of the control allocation matrix

[0096] In one embodiment, the control allocation matrix is ​​simplified by using the reference tilt angle characteristic in the rotor mode, including:

[0097] The control allocation matrix is ​​simplified by using the reference tilt angle characteristics under the rotor mode:

[0098]

[0099] Among them, k f represents the thrust constant of the rotor, r represents the distance between the front and rear rotors, 0<ε<1 is the center of gravity position parameter, and εr represents the longitudinal distance of the front rotor relative to the center of gravity.

[0100] In one embodiment, the virtual control variable includes a virtual pitch control torque in a stable hovering state; and the tension constant and the center of gravity position parameter are corrected according to the virtual control variable to obtain accurate control distribution parameters, including:

[0101] According to the virtual pitch control torque in the stable hovering state, the tension constant and the center of gravity position parameters are corrected to obtain the accurate control distribution parameters:

[0102]

[0103] Where G represents the gravity of the aircraft, k′ f , ε′ respectively represent the measured values ​​of the rotor thrust constant and the center of gravity position parameter, Γ y represents the virtual pitch control torque in the stable hovering state, T represents the virtual thrust, and r represents the distance parameter.

[0104] To more intuitively demonstrate the effectiveness of the present invention, simulations were performed using MATLAB software. Considering practical application scenarios, a tilt-rotor tri-rotor unmanned aerial vehicle (UAV) with a fixed tail rotor was used as the controlled object, representing the nonlinear platform in this embodiment. The control allocation method proposed in this invention was used to address the control allocation issues of the UAV, verifying the effectiveness of the present invention.

[0105] Step 1: Establish a control allocation model for a tilt-rotor tri-rotor UAV;

[0106] The control allocation model of the tilt-rotor tri-rotor UAV in this embodiment is shown below. The physical measurement parameters in the model can be obtained through identification experiments. f =4.513×10 -5 , k d =9.409×10 -7 , r 1x =0.22m, r 1y =0.32m, r 3x =-0.44m.

[0107]

[0108] Step 2: Based on the control allocation model in step 1, design a control allocation algorithm;

[0109] The solution process is iterated step by step, and a decoupling control allocation method is designed. First, the tilt angle {α1, α2, α3} is calculated, and then the rotor speed {ω1, ω2, ω3} is calculated. The tilt angle and the virtual heading control torque Γ z Related, in the rotor mode, α3 = 0, introducing proportional control, the tilt angle is:

[0110]

[0111] Roll, pitch, and altitude control are achieved by adjusting the rotor speed. Based on the distribution model and tilt angle, the rotor speed is:

[0112]

[0113]

[0114] Step 3: Analyze the control allocation parameter perturbation problem;

[0115] Further analysis of the specific factors affecting the control distribution accuracy, for the rotor power system, the torque constant k d Much smaller than the tensile constant k f , and the reference tilt angle α in the rotor mode is 0, the tilt angles α1 and α2 are very small, and the control allocation matrix H can be simplified to:

[0116]

[0117] Where r = 0.66m represents the distance between the front and rear rotors, and ε = 1 / 3 is the center of gravity position parameter. Considering the interference of airflow on the rotors and the change of the center of gravity of the aircraft, the uncertainty in the control allocation matrix mainly comes from the tension constant and the center of gravity position parameter, that is, the parameter k f There is an error between the measured value of ε and the true value in dynamic flight.

[0118] Step 4: Design a control allocation parameter correction method;

[0119] For the two perturbation parameters in step 3, a control allocation parameter correction method is designed to obtain accurate model parameters, improve control allocation accuracy and control performance. The control allocation parameters are all accurate values ​​and k f , ε, the measured values ​​of tension constant and center of gravity position parameters are represented by k′ f ,ε′ indicates that the control allocation parameters satisfy:

[0120]

[0121] {Γ y , T} represents the virtual control quantity collected in the stable hovering state, and G = 53.9N represents gravity.

[0122] Step 5: Comprehensively apply the methods of steps 1, 2, 3, and 4 to implement the control allocation of the tilt-rotor tri-rotor UAV to achieve efficient and robust control allocation effects.

[0123] For the above aircraft model and control parameters, the control allocation algorithm and control allocation correction method of the present invention are used to perform simulation. Figure 3 The simulation demonstrates the pitch channel tracking performance and the evolution of the virtual control variable, both without and with corrections, when the controller and its parameters remain consistent. The black curve represents the desired pitch angle, the dashed line represents the tracking result without corrections, and the dotted line represents the tracking result after the control allocation parameter correction method is introduced. Simulation results demonstrate that the control allocation method effectively distributes virtual control torque, forming a closed control loop. The introduction of the control allocation parameter correction significantly improves control allocation accuracy and pitch tracking performance.

[0124] It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. In addition, Figure 1 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0125] In one embodiment, Figure 4 As shown, a control distribution device for a tilt-rotor tri-rotor UAV is provided, comprising: a data acquisition module 402, a control distribution model construction module 404, a tilt angle solution module 406, a control distribution accuracy influencing factor analysis module 408, a perturbation parameter correction module 410, and a rotor speed solution module 412, wherein:

[0126] The data acquisition module 402 is used to obtain virtual control quantities and actuator control instructions of the tilt-rotor tri-rotor UAV; the virtual control quantities include virtual thrust and virtual control torque;

[0127] A control allocation model building module 404 is used to build a control allocation model of the tilt-rotor UAV based on the virtual thrust and virtual control torque and the actuator control instructions;

[0128] The tilt angle solving module 406 is used to solve the control allocation model of the tilt-rotor UAV using a decoupled control allocation method, iterating the solution process step by step to obtain a relationship matrix between the tilt angle, rotor speed, and the control allocation matrix;

[0129] The control allocation accuracy influencing factor analysis module 406 is configured to analyze the factors influencing the control allocation accuracy based on the decoupled control allocation method, simplify the control allocation matrix using the reference tilt angle characteristics under the rotor mode, analyze the control allocation matrix, and obtain perturbation parameters; the perturbation parameters include the tension constant and the center of gravity position parameter;

[0130] The perturbation parameter correction module 410 is used to collect virtual control quantities in a stable hovering state, and correct the tension constant and the center of gravity position parameters according to the virtual control quantities to obtain accurate control distribution parameters;

[0131] The rotor speed solving module 412 is used to modify the control allocation matrix using accurate control allocation parameters, and solve the relationship matrix between the rotor speed and the control allocation matrix according to the modified control allocation matrix to obtain the rotor speed.

[0132] The specific definition of a tilt-rotor tri-rotor unmanned aerial vehicle control distribution device can be found in the definition of a tilt-rotor tri-rotor unmanned aerial vehicle control distribution method described above and will not be repeated here. Each module in the aforementioned tilt-rotor tri-rotor unmanned aerial vehicle control distribution device can be implemented in whole or in part through software, hardware, or a combination thereof. Each of the aforementioned modules can be embedded in or independent of a processor in a computer device in hardware form, or can be stored in a computer device memory in software form, so that the processor can call and execute the corresponding operations of each of the aforementioned modules.

[0133] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0134] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A tilt-rotor tri-rotor UAV control allocation method, characterized in that: The method comprises: Obtaining virtual control quantities and actuator control instructions for the tilt-rotor tri-rotor UAV; the virtual control quantities include virtual thrust and virtual control torque; Constructing a control distribution model for the tilt-rotor UAV according to the virtual thrust and virtual control torque and actuator control instructions; The control allocation model of the tilt-rotor UAV is solved using a decoupling control allocation method, and the solution process is iteratively performed step by step to obtain a relationship matrix between the tilt angle, the rotor speed, and the control allocation matrix; Analyzing factors influencing control allocation accuracy according to the decoupling control allocation method, simplifying the control allocation matrix using the reference tilt angle characteristics under the rotor mode, analyzing the control allocation matrix to obtain perturbation parameters; the perturbation parameters include a tension constant and a center of gravity position parameter; Collecting virtual control quantities in a stable hovering state, and correcting the tension constant and center of gravity position parameters according to the virtual control quantities to obtain accurate control distribution parameters; The control allocation matrix is ​​corrected using the accurate control allocation parameters, and a relationship matrix between the rotor speed and the control allocation matrix is ​​solved according to the corrected control allocation matrix to obtain the rotor speed.

2. The method according to claim 1, characterized in that A control distribution model for the tilt-rotor UAV is constructed according to the virtual thrust, the virtual control torque, and the actuator control instructions, including: The control distribution model of the tilt-rotor UAV is constructed according to the virtual thrust, virtual control torque and actuator control instructions: Among them, {Γ x , Γ y , Γ z } represents the virtual control torque, T represents the virtual thrust, {ω1, ω2, ω3} represents the three rotor speeds of the actuator, {α1, α2, α3} represents the three tilt angles of the actuator, c* represents cos(*), s* represents sin(*), ω i With α i denote the rotation speed and tilt angle of rotor i, respectively, (r ix , r iy ) is the position of rotor i relative to the center of gravity, k f 、k d They represent the thrust constant and torque coefficient of the rotor respectively.

3. The method according to claim 1, characterized in that The control allocation model of the tilt-rotor UAV is solved using a decoupled control allocation method. The solution process is iteratively performed step by step to calculate the tilt angle and rotor speed, including: The control allocation model of the tilt-rotor UAV is solved using a decoupling control allocation method. A reference proportional control is introduced during the solution process to construct a relationship matrix between the tilt angle and the virtual heading control torque. Roll, pitch and altitude control are performed by adjusting the rotor speed, and a relationship matrix between the rotor speed and the control allocation matrix is ​​constructed; The relationship matrix between the tilt angle and the virtual heading control torque is solved to obtain the tilt angle.

4. The method according to claim 3, characterized in that In the solution process, reference proportional control is introduced to construct the relationship matrix between the tilt angle and the virtual heading control torque, including: In the solution process, the reference proportional control is introduced to construct the relationship matrix between the tilt angle and the virtual heading control torque: Where α represents the reference tilt angle related to the flight mode, δ is a positive constant, and Γ z Indicates the virtual heading control torque.

5. The method according to claim 3, characterized in that By adjusting the rotor speed to control roll, pitch and altitude, a relationship matrix between the rotor speed and the control allocation matrix is ​​constructed, including: By adjusting the rotor speed to perform roll, pitch and altitude control, the relationship matrix between the rotor speed and the control allocation matrix is ​​constructed as follows: Among them, Γ x represents the virtual roll control torque, Γ y represents the virtual pitch control torque, (ω1, ω2, ω3} represents the three rotor speeds of the actuator, and H -1 represents the inverse of the control allocation matrix.

6. The method according to claim 2, characterized in that The control allocation matrix is ​​simplified by using the reference tilt angle characteristics under the rotor mode, including: The control allocation matrix is ​​simplified by using the reference tilt angle characteristics under the rotor mode: Among them, k f represents the thrust constant of the rotor, r represents the distance between the front and rear rotors, 0<ε<1 is the center of gravity position parameter, and εr represents the longitudinal distance of the front rotor relative to the center of gravity.

7. The method according to claim 2, characterized in that The virtual control amount includes a virtual pitch control torque in a stable hovering state; The tension constant and the center of gravity position parameter are corrected according to the virtual control amount to obtain accurate control distribution parameters, including: The tension constant and the center of gravity position parameters are corrected according to the virtual pitch control torque in the stable hovering state to obtain the accurate control distribution parameters: Where G represents the gravity of the aircraft, k′ f , ε′ respectively represent the measured values ​​of the rotor thrust constant and the center of gravity position parameter, Γ y represents the virtual pitch control torque in the stable hovering state, T represents the virtual thrust, and r represents the distance parameter.

8. A tilt-rotor tri-rotor UAV control distribution device, characterized in that: The device comprises: A data acquisition module is used to obtain virtual control quantities and actuator control instructions of the tilt-rotor tri-rotor UAV; the virtual control quantities include virtual thrust and virtual control torque; a control allocation model building module, configured to build a control allocation model for the tilt-rotor UAV based on the virtual thrust and virtual control torque and actuator control instructions; A tilt angle solving module is used to solve the control allocation model of the tilt-rotor UAV using a decoupling control allocation method, iteratively performing the solution process step by step to obtain a relationship matrix between the tilt angle, rotor speed, and the control allocation matrix; a control allocation accuracy influencing factor analysis module, configured to analyze the factors influencing the control allocation accuracy according to the decoupled control allocation method, simplify the control allocation matrix using the reference tilt angle characteristic under the rotor mode, analyze the control allocation matrix, and obtain perturbation parameters; the perturbation parameters include a tension constant and a center of gravity position parameter; a perturbation parameter correction module, configured to collect virtual control quantities in a stable hovering state, and correct the tension constant and center of gravity position parameters according to the virtual control quantities to obtain accurate control allocation parameters; The rotor speed solving module is used to correct the control allocation matrix using the accurate control allocation parameters, and solve the relationship matrix between the rotor speed and the control allocation matrix according to the corrected control allocation matrix to obtain the rotor speed.

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