An unmanned aerial vehicle performance ground test verification platform and method

Abstract

The application discloses a kind of unmanned aerial vehicle performance ground test verification platform and method, for the comprehensive test of multi-rotor unmanned aerial vehicle function and performance parameter, ground verification, evaluation and airworthiness determination.The present application is tested through indoor platform, and a single person can operate, without organizing large-scale manpower and material resources to carry out field test, shorten test preparation time, reduce manpower, equipment and comprehensive cost such as site.The present application can place verification platform in controllable test environment, fix unmanned aerial vehicle on verification platform, while accurately simulating weather, airspace and various complex external scenes, controllable throughout, avoid unmanned aerial vehicle crash and other risks in field test.Finally, the present application integrates high-precision sensor to collect data, can capture unmanned aerial vehicle deflection angle, lift and operation data in real time for specific working conditions, ensure the accuracy, integrity and timeliness of data, provide solid data support for performance in-depth analysis, algorithm iteration and system optimization.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of unmanned system testing, and particularly relates to a UAV performance ground test verification platform and method, which is used for comprehensive testing, ground verification, evaluation and airworthiness judgment of multi-rotor UAV functions and performance parameters. BACKGROUND

[0002] With the deep integration and wide application of UAV technology in military, industrial, civil and other fields, the system complexity, task reliability and safety requirements of UAV are increasingly improved. However, the current research and development, verification and airworthiness certification of UAVs are heavily dependent on field flight testing. This traditional testing method has many bottlenecks:

[0003] (1) Long testing period and high cost: a large amount of manpower, material resources and a large amount of time are required.

[0004] (2) Uncontrollable environment and high risk: affected by external factors such as weather and airspace, it is difficult to test the performance boundary, fault injection and intelligent algorithm verification in complex environment, and once a fault occurs, it may cause the UAV to crash, resulting in property loss and even personnel casualties.

[0005] (3) Incomplete data collection: field testing cannot accurately and comprehensively collect all dynamic parameters of UAV under specific working conditions, which limits the in-depth analysis and optimization of its performance.

[0006] Therefore, there is a lack of a comprehensive indoor test platform that can simulate multi-degree-of-freedom motion, synchronously and accurately measure force and displacement, and integrate data visualization and analysis functions; and before field flight, the necessary flight conditions of the UAV are fully verified in a safe and controllable indoor environment. SUMMARY

[0007] In view of the deficiencies in the prior art, the purpose of the present application is to provide a UAV performance ground test verification platform and method, which simulates the flight state of a multi-rotor UAV on the ground, tests the deflection angle, lift and motor speed of the UAV, and realizes the verification and evaluation of the function parameters of the multi-rotor UAV, thereby providing technical support for field flight testing and airworthiness certification.

[0008] To achieve the above purpose, the first aspect of the present application provides a UAV performance ground test verification platform, comprising:

[0009] an upper circular table for rigidly fixing a measured multi-rotor UAV, and making the center of gravity of the UAV coaxial with the center of rotation of the upper circular table;

[0010] a cross-axis universal joint arranged between the upper circular table and the intermediate rod, which gives the upper circular table a double-degree-of-freedom deflection capability around the X and Y axes;

[0011] An intermediate rod is fixedly connected with the cross shaft universal joint at an upper end and is connected with a dynamic force sensor at a lower end through a dynamic force sensor pressure head, and the dynamic force sensor is used for collecting the overall lift of the unmanned aerial vehicle in real time;

[0012] The guide rail units are not less than three groups, and each guide rail unit comprises:

[0013] A guide rail and a guide rail slider are used for providing radial translation guidance;

[0014] A grating ruler slide rail and a grating ruler slider are used for measuring the displacement of the slider in real time;

[0015] An upper side rod and a lower side rod are connected with each other through a side rod force sensor, and the side rod force sensor is used for acquiring the axial force of the rod;

[0016] An upper spherical hinge and a lower spherical hinge are respectively connected with the upper end of the upper side rod and the bottom end of the lower side rod to the upper circular table and the grating ruler slider, and a spatial spherical pair is formed;

[0017] A control and data acquisition system is used for synchronously collecting the real-time signals of the dynamic force sensor, the side rod force sensor and the grating ruler, and calculating the spatial deflection angle of the upper circular table, the overall lift and the lift distribution of each rotor according to the signals, so as to complete the performance verification of the unmanned aerial vehicle in an indoor environment.

[0018] The second aspect of the present application also provides a method for verifying the performance of an unmanned aerial vehicle on the ground, which adopts the platform and comprises the following steps:

[0019] S1: building the verification platform and modeling the platform;

[0020] S2: fixing and installing the unmanned aerial vehicle, controlling the unmanned aerial vehicle through a remote controller, and testing the deflection angle of the unmanned aerial vehicle based on the moving distance of the slider of the guide rail unit;

[0021] S3: calculating the component force in the direction perpendicular to the rotation plane of the rotor according to the detection data of the dynamic force sensor and each guide rail unit, and calculating the resultant force as the overall lift of the unmanned aerial vehicle;

[0022] S4: controlling the unmanned aerial vehicle to be in a static working condition at any angle, solving the pitch angle and the roll angle according to the overall slope angle and the overall yaw angle of the unmanned aerial vehicle, further calculating the pitch moment and the roll moment, and selecting the standardized solution meeting the preset standard from the motor speed solution set according to the mixed control logic to obtain the lift of a single motor of the unmanned aerial vehicle and further obtain the motor speed;

[0023] S5: placing the verification platform in a controllable test environment, and accurately simulating various complex external scenes to capture the deflection angle, the lift and the operation data of the unmanned aerial vehicle in real time for specific working conditions.

[0024] Based on the above technical solution, the present application has the following beneficial effects:

[0025] (1) Cycle is greatly shortened, cost is significantly reduced: test on indoor platform, single person can operate, no need to organize large-scale manpower and material resources to carry out field test, shorten test preparation time, reduce comprehensive cost of manpower, equipment and site, etc.

[0026] (2) Environment is controllable, risk is extremely reduced: the verification platform can be placed in a controllable test environment, the unmanned aerial vehicle is fixed on the verification platform, and various complex external scenes such as weather and airspace are simulated accurately, which is controllable throughout the process, avoiding the risk of unmanned aerial vehicle crash in field test.

[0027] (3) Data collection is comprehensive and accurate, supporting deep optimization: integrated high-precision sensor data collection can capture unmanned aerial vehicle deflection angle, lift and operation data in real time for specific working conditions, ensuring the accuracy, integrity and timeliness of the data, and providing solid data support for performance in-depth analysis, algorithm iteration and system optimization. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a structural diagram of an unmanned aerial vehicle performance ground test verification platform according to an embodiment of the present application;

[0029] Figure 2 is an exploded view of Figure 1 ;

[0030] Figure 3 is a top view of Figure 1 ;

[0031] Figure 4 is a side view of Figure 1 ;

[0032] Figure 5 is a model schematic diagram constructed according to Figure 1 ;

[0033] Figure 6 is a working method flow chart of an unmanned aerial vehicle performance ground test verification platform according to an embodiment of the present application;

[0034] Figure 7 is a schematic diagram of the displacement deflection of the upper circular table of Figure 5 in a single direction;

[0035] Figure 8 is a schematic diagram of the plane equation of Figure 5 ;

[0036] Figure 9 is a plane lift decomposition diagram of Figure 5 ;

[0037] Figure 10 is a schematic diagram of the distribution of the four-rotor unmanned aerial vehicle motor selected by the present application. DETAILED DESCRIPTION

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed in the embodiments will be briefly introduced as follows. Obviously, the accompanying drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without any creative effort.

[0039] The embodiment of the present application first provides a UAV performance ground test verification platform, comprising:

[0040] A lower base for overall support and fixing to the ground;

[0041] An upper circular table for rigidly fixing a measured multi-rotor UAV and coaxially arranging the UAV gravity center and the upper circular table rotation center;

[0042] A cross-axis universal joint arranged between the upper circular table and the middle rod, and giving the upper circular table a double-degree-of-freedom deflection capability around the X and Y axes;

[0043] A middle rod, the upper end of which is fixedly connected with the cross-axis universal joint, and the lower end of which is connected with a dynamic force sensor through a dynamic force sensor pressure head, and the dynamic force sensor is fixed to the lower base and used for real-time collection of the overall lift of the UAV;

[0044] No less than three groups of guide rail units are evenly distributed between the lower base and the upper circular table, and each group of guide rail units comprises:

[0045] A support frame fixedly connected with the lower base;

[0046] A guide rail and a guide rail slider for providing radial translation guidance;

[0047] A grating ruler slide rail and a grating ruler slider for real-time measurement of the slider displacement;

[0048] An upper side rod and a lower side rod, between which a side rod force sensor is connected in series, and used for acquiring the axial force of the rod;

[0049] An upper spherical hinge and a lower spherical hinge, which respectively connect the upper end of the upper side rod to the upper circular table and connect the bottom end of the lower side rod to the grating ruler slider, and form a spatial spherical pair;

[0050] A control and data acquisition system for synchronously collecting real-time signals of the dynamic force sensor, the side rod force sensor and the grating ruler, and calculating the spatial deflection angle of the upper circular table, the overall lift and the lift distribution of each rotor according to the real-time signals, so as to complete the performance verification of the UAV in an indoor environment.

[0051] The embodiment of the present application also provides a UAV performance ground test verification method, which adopts the above platform and comprises the following steps:

[0052] S1: build a verification platform and model it;

[0053] S2: fix the unmanned aerial vehicle, control the remote controller to control the unmanned aerial vehicle, and test the deflection angle of the unmanned aerial vehicle based on the moving distance of the slider of the guide rail unit;

[0054] S3: calculate the component force perpendicular to the rotating plane direction of the rotor based on the detection data of the dynamic force sensor and each guide rail unit, and calculate the resultant force as the overall lift of the unmanned aerial vehicle;

[0055] S4: control the unmanned aerial vehicle to be in an arbitrary angle static working condition, solve the pitch angle and roll angle based on the overall slope angle and overall yaw angle of the unmanned aerial vehicle, further calculate the pitch moment and roll moment, and select the standardized solution meeting the preset standard from the motor speed solution set based on the mixed control logic to obtain the unmanned aerial vehicle single motor lift and further obtain the motor speed;

[0056] S5: place the verification platform in a controllable test environment, and simultaneously accurately simulate various complex external scenes to capture the unmanned aerial vehicle deflection angle, lift and operation data in real time for specific working conditions.

[0057] Based on the same concept as the above embodiment, as shown in Figure 1 , Figure 3 and Figure 4 , the test example selects three guide rails to constitute an unmanned aerial vehicle performance ground test verification platform, specifically:

[0058] Lower base 1, first guide rail unit 2, second guide rail unit 3, third guide rail unit 4, upper circular table 5, cross shaft universal joint 6, intermediate rod 7, dynamic force sensor pressure head 8 and dynamic force sensor 9.

[0059] One end of the cross shaft universal joint 6 is connected and fixed with the upper circular table 5 through threads, and the other end is connected with the intermediate rod 7; the lower end of the intermediate rod 7 is provided with a dynamic force sensor pressure head 8 through a screw, the pressure head is connected with a dynamic force sensor 9, and the dynamic force sensor 9 is finally fixed on the lower base 1 through a bolt and a nut, to jointly constitute a complete force detection system.

[0060] Further, as shown in Figure 2 , the first guide rail unit 2 comprises a support frame 21, a guide rail 22, a guide rail slider 23, a connecting piece 24, a grating ruler slider 25, a grating ruler slide rail 26, a lower spherical hinge 271, an upper spherical hinge 272, a lower side rod 281, an upper side rod 282 and a side rod force sensor 29.

[0061] The lower base 1 and each support frame are made of steel, and the four are connected and fixed through screws to enhance the stability and structural firmness of the overall base.

[0062] It is worth noting that the first guide rail unit 2, the second guide rail unit 3 and the third guide rail unit 4 have the same specific assembly mode and structure. The specific assembly mode of the first guide rail unit 2 will be described in detail below:

[0063] The guide rail 22 is mounted on the support frame 21 and fixed by screws; the guide rail slider 23 is designed as a roller and is paired with the guide rail 22 to slide freely along the guide rail 22. The upper part of the guide rail slider 23 is connected to the connecting piece 24 by screws to achieve smooth transmission. The grating ruler slide rail 26 is fixed to the support frame 21 by means of side holes through the cooperation of bolts and nuts; the grating ruler slide block 25 is matched with the grating ruler slide rail 26 and can slide smoothly. The grating ruler slide block 25 is further rigidly connected to the connecting piece 24 through bolts and nuts. The side rod force sensor 29 has its two ends connected to the lower side rod 281 and the upper side rod 282, respectively, wherein the other end of the lower side rod 281 is fixed to the connecting piece 24 by means of the lower spherical hinge 271 and screws, and the other end of the upper side rod 282 is also fixed to the upper circular table 5 by means of the upper spherical hinge 272 and screws, forming a flexible force transmission support structure.

[0064] The three side rod force sensors are used to measure the tension and pressure in the corresponding directions, and the dynamic force sensor 9 in the middle measures the force in the vertical direction. The grating ruler measures the displacement in three directions, and the displacement can be used to calculate the deflection angle of the upper circular table 5 in three directions; then the three deflection angles are coupled to calculate the deflection angle of the entire upper circular table 5.

[0065] Among them, the upper and lower spherical hinges can realize three degrees of freedom deflection, and the deflection angle range is limited within 45 degrees with the vertical direction of its base; the cross shaft universal joint 6 can realize two degrees of freedom deflection.

[0066] As shown in Figure 5 , the overall structure of the above device is modeled, wherein the gray line represents the overall structure model of the upper circular table in the initial horizontal state, and the black line represents the overall structure model of the upper circular table after deflection. The centers of the three upper spherical hinges are defined as , the centers of the three lower spherical hinges are defined as , , and the vertical distance from the middle rod axis to the vertical point is , and the vertical point is defined as . In the initial horizontal state of the upper circular table, the coordinate system is defined as : the center of rotation of the cross shaft universal joint 6 is taken as the origin of the coordinate system , and the point is in the same plane, and the direction is taken as the positive direction of the axis, the axis is along the point, and the horizontal counterclockwise rotation of 90 degrees is the The positive direction of the axis, the vertical direction is The positive direction of the axis, the vertical direction is The length is , The length is , The length is . The upper spherical hinge after the upper circular truncated cone is deflected The lower spherical hinge after the upper circular truncated cone is deflected

[0067] As Figure 6 shown, on the basis of the above, based on the same concept of the method of the embodiment of the application, the test example of the application further provides a detailed calculation derivation process, specifically:

[0068] Step 1: Fix the unmanned aerial vehicle, control the remote controller to control the unmanned aerial vehicle; based on the sliding distance of the guide rail unit, test the deflection angle of the unmanned aerial vehicle. Specifically:

[0069] Fix the unmanned aerial vehicle at a predetermined position on the upper circular truncated cone, and the center of gravity of the machine body is on the same vertical line as point The head points to The positive direction of the axis. Control the remote controller to give the unmanned aerial vehicle a basic lift and keep it unchanged, and then control the unmanned aerial vehicle pitch and roll through the remote controller.

[0070] Use the model to solve the slope angle of a single direction by a single direction . Take the first guide rail unit as an example, the moving distance of the guide rail slider is read by the signal output by the grating ruler slider , which changes dynamically over time. According to the spatial geometric mapping relationship, the specific calculation method is as follows:

[0071] As Figure 7 shown, when the unmanned aerial vehicle pitches along the straight line , the slope angle of the straight line deflected to the straight line is defined as , which can be expressed as , wherein is the angle between the straight line and the straight line after the unmanned aerial vehicle is deflected. When the unmanned aerial vehicle does not have yaw motion (i.e. does not rotate along the vertical direction), point only does translational motion in the plane.

[0072] Connect point and point , and take it as an auxiliary line segment, and the length is .

[0073]

[0074]

[0075]

[0076] Similarly, when the second guide rail unit and the third guide rail unit move, the corresponding slope angle is:

[0077]

[0078] When the slope angle of point is calculated, the projection of the straight line connecting point and point on the plane forms an angle with the axis, which is the yaw angle . According to the calculation result of the slope angle and the yaw angle , the plane equation of point is solved, and the specific calculation process is as follows:

[0079] As shown in Figure 8 , let the plane equation of point be . For any point on the plane, connect the origin and point to form a straight line , and the angle between the straight line and the plane is denoted as (i.e., the slope angle), the projection of point on the plane is point , and connect the origin and point to form a straight line , and the angle between the straight line and the axis is denoted as (i.e., the yaw angle). The direction vector of the straight line is , and the included angle between the direction vector and the plane is , which satisfies . Substitute point into the above plane equation to obtain , and the yaw angle of point satisfies Therefore, in polar coordinates, we have ,in Substituting the above polar coordinates into... We can obtain:

[0080] (5)

[0081] Based on the above reasoning process, the following conclusion can be drawn: For a plane any point on Its slope angle and yaw angle All satisfy the result of equation (5), that is:

[0082] (6)

[0083] Therefore, we can conclude that for a plane Three feature points on Their respective slope angles With yaw angle All satisfy the spatial geometric relationship defined by equation (6), that is: (7)

[0084] Known Direction is Positive direction of axis, straight line The two sides form a 120-degree angle with each other; after the drone deflects, the plane... If the relationship between the points on the line remains unchanged, then the line... They also form a 120-degree angle with each other, point Yaw angle They are respectively Then we can obtain:

[0085] (8)

[0086] Theoretically satisfied .

[0087] From point The relationship between the slope angle and the yaw angle is as follows: (9)

[0088] From point The relationship between the slope angle and the yaw angle is as follows: (10)

[0089] From the above, we can derive the equation of the plane as: (11), or (12).

[0090] Define the plane slope angle as the plane With the horizontal plane (i.e.) The angle between the plane and the axis, i.e. the overall pitch angle of the UAV, is denoted as The plane yaw angle is the angle between the plane and the axis, i.e. the overall yaw angle of the UAV, is denoted as The projection of the line on which the direction with the largest pitch angle lies on the plane, and the axis, i.e. the overall pitch angle of the UAV, is denoted as The projection of the line on which the direction with the largest pitch angle lies on the plane, and the axis, i.e. the overall pitch angle of the UAV, is denoted as The projection of the line on which the direction with the largest pitch angle lies on the plane, and the axis, i.e. the overall pitch angle of the UAV, is denoted as The plane equation of the plane is The normal vector of the plane is .

[0091] The overall pitch angle of the UAV can be expressed as:

[0092] (13)

[0093] The overall yaw angle of the UAV can be expressed as:

[0094] (14)

[0095] Step 2: Test the lift of the UAV. Fix the UAV at a predetermined position on the upper circular table, and make the rotor rotation plane of the UAV parallel to the upper surface of the upper circular table. Control the remote controller to give the UAV a lift signal, and control the pitch and roll of the UAV. Based on the installation relationship, calculate the component force in the direction perpendicular to the rotor rotation plane according to the data detected by the dynamic force sensor and the three side rod force sensors, and further obtain the overall lift of the UAV. According to the spatial geometric mapping relationship, the specific calculation method is as follows:

[0096] As shown in FIG. 4, it is known that the upper circular table is parallel to the plane, and the corresponding relationship between the force of the point along the vertical direction of the plane (i.e. the lift perpendicular to the rotor rotation plane), the detection force of the guide rail unit side rod force sensor and the plane yaw angle is calculated. Wherein, Figure 9 Based on this derivation logic, The vertical force of the four points corresponding to the rotor rotation plane, and the detection force of the corresponding mechanical sensor, satisfy:

[0097] (15) ​​​​​​​​​​​​​​

[0098] wherein, are the angles between the straight line and the normal vector of the plane .

[0099] Take the first guide rail unit as an example, when the guide rail slider moves, the moving distance is obtained by reading the signal output by the grating ruler slider, which dynamically changes with time. The mathematical relationship between and is calculated by spatial geometric mapping, and the specific calculation method is as follows:

[0100] Given the plane equation , the normal vector , and the coordinates of point and point , then the direction vector is: According to the formula of the angle between a straight line and the normal of a plane, we get:

[0101] (17)

[0102] As above, in the second guide rail unit and the third guide rail unit, the angle between the extension line of the lower side rod of the second guide rail unit and the lower side rod of the third guide rail unit and the normal vector of the plane is , and the corresponding cosine value is: (18)

[0103] Then the relationship between the detection force of the three side rod force sensors and the corresponding force is: (19)

[0104] The force of the middle rod and the force of the corresponding vertical plane are related as: (20)

[0105] The overall lift of the UAV can be represented as: (21)

[0106] Step 3: Test the motor speed of the UAV based on the UAV performance ground test verification platform. Control the UAV to be in any angle static working condition, at this time the parameters measured by the UAV performance ground test verification platform are fixed values and do not change with time.

[0107] Establish the relationship between the lift of a single motor and the motor speed. For a single motor, the lift generated by the rotation of the rotor ​​With motor speed They are directly proportional, that is, they satisfy the relational expression. ,in It is the thrust coefficient; the thrust coefficient With air density propeller diameter And related to the geometric design parameters of the propeller, it can be approximated as follows: (in It is a coefficient that integrates all the aerodynamic characteristics of a propeller.

[0108] like Figure 10 As shown, this test case uses a quadcopter drone as the application object, and the propeller geometry design parameters of the four rotors of the quadcopter drone are kept consistent. When the quadcopter drone is in a hovering state, the sum of the lift generated by the rotation of the four rotors is equal to the total weight of the drone. The corresponding mathematical model can be expressed as follows: (in The lift generated by each of the four rotors is respectively. (where is the total weight of the UAV). Replacing the lift of each rotor with its corresponding motor speed expression, we can obtain: ,in Motors The rotational speed. When the quadcopter UAV is in flight, the total lift generated by its four rotors must meet the following requirements. .

[0109] Utilizing the overall lift of the drone Overall slope angle of the drone and the overall yaw angle of the drone Solve for the rotational speeds of the four motors of the drone. Based on the drone control logic in this test case, the final output speed of each motor is determined by the base lift. Pitch control signals Roll control signal and yaw control signals The result is obtained by superposition: final motor speed = base lift + pitch control + roll control + yaw control. The motor speed value can be output by the flight controller, and the specific calculation method is as follows:

[0110] Under static operating conditions, based on the overall lift of the UAV Overall slope angle of the drone and the overall yaw angle of the drone A set of possible solutions of the motor speed can be calculated, but the unique solution of the motor speed cannot be determined. The present test case solves the above problem of no unique solution by a mixer integrated in the PID controller. Specifically, the mixer can filter a standardized solution meeting a preset standard from the solution set. The mixer is internally preset with a fixed distribution matrix. For an X-shaped layout of the unmanned aerial vehicle, the mixer logic is as follows:

[0111] (22)

[0112] wherein, represents the basic lift distributed by a single motor; the pitch control amount (wherein is the pitch moment); the roll control amount (wherein is the roll moment); is a constant factor containing the force arm and the layout (the overall layout of the unmanned aerial vehicle plus the rotor structure). This structure does not consider yaw, so the yaw control amount . Therefore, the four motor lifts of the quad-rotor unmanned aerial vehicle can be expressed as (23)

[0113] The four motors of the quad-rotor unmanned aerial vehicle are set to have the same length of force arm to the center of gravity of the unmanned aerial vehicle, and the length of the force arm is denoted as When the unmanned aerial vehicle is in a static deflection state (i.e., has a preset deflection angle), the PID controller carried by the unmanned aerial vehicle can calculate the moment required to operate the unmanned aerial vehicle to the target attitude based on the lift relationship defined above:

[0114] (24)

[0115] In the static balance working condition, the pitch moment is related to the pitch angle of the unmanned aerial vehicle, and satisfies the relationship ; the roll moment is related to the roll angle , and satisfies the relationship (wherein is the mass of the unmanned aerial vehicle, is the acceleration of gravity, is the vertical distance from the center of gravity of the unmanned aerial vehicle to the rotor plane), and the relationship between the moment and the control amount can be obtained by substituting formula (23) into formula (24): (25)

[0116] Substituting formula (25) into formula (23) can obtain the four motor lifts and the total lift of the unmanned aerial vehicle, the pitch angle and the roll angle Relationships:

[0117] (26)

[0118] It is known that the four motors of a quadcopter each generate a lift force with the total lift force of the quadcopter , a pitch angle and a roll angle , based on which the pitch angle and the roll angle of the quadcopter can be solved based on the overall slope angle and the overall yaw angle of the quadcopter. In this test example, the head of the quadcopter is set to point to the positive direction of the axis of the world coordinate system, the pitch angle is the angle of rotation of the quadcopter around the axis of the world coordinate system, and the roll angle is the angle of rotation of the quadcopter around the axis of the world coordinate system.

[0119] Based on the above parameter definitions, the mapping relationship between the pitch angle , the roll angle , the overall slope angle and the overall yaw angle of the quadcopter needs to be further established and solved. The most commonly used implementation is to solve it through rotation matrix operation:

[0120] 1) After the quadcopter is deflected, the spatial direction vector of the axis of the quadcopter body can be represented using a spherical coordinate system: .

[0121] 2) The Z-Y-X rotation matrix used in this test example is a commonly used matrix for spatial angle conversion, and the relationship between the quadcopter body coordinate system and the pitch angle and the roll angle can be established, and the combined rotation matrix is specifically set as: wherein is the rotation matrix around the axis, which is in a mapping relationship with the roll angle , and is the rotation matrix around the axis, which is in a mapping relationship with the pitch angle . , The model expression is:

[0122] (27)

[0123] (28)

[0124] The combined rotation matrix is calculated as:

[0125] (29)

[0126] The body frame is initially in a horizontal state, and the UAV body coordinate system is The axis vector (0, 0, 1) becomes: (30)

[0127] After the UAV rotates, the overall slope angle of the UAV is utilized and the overall yaw angle of the UAV is utilized The body coordinate system is calculated The axis vector should be the same as the body coordinate system calculated by the pitch angle and the roll angle The body coordinate system is calculated The axis vector is in the same direction, that is: (31)

[0128] Solving the equation, we get:

[0129] (32)

[0130] The pitch angle and the roll angle are related to the overall slope angle of the UAV and the overall yaw angle of the UAV as follows: (33)

[0131] Based on the above calculations, the four motor speeds of the quadrotor UAV can be represented as:

[0132] (34)

[0133] According to formulas (13) and (14), the dynamic changes of the overall slope angle of the UAV and the overall yaw angle of the UAV can be analyzed. Given a fixed deflection angle of the UAV, the static working condition can also be maintained, and whether the factory UAV can reach the given deflection angle can also be tested through step 1.

[0134] According to formula (21), the dynamic changes of the UAV lift can be analyzed. Given a fixed lift value of the UAV, the static working condition can also be maintained, and whether the factory UAV can reach the given lift value can also be tested through step 2.​

[0135] According to formula (34), the four motor speeds of the quad-rotor unmanned aerial vehicle in the static working condition can be analyzed Given a fixed value of the four motor speeds of the quad-rotor unmanned aerial vehicle, the static working condition is maintained, and whether the unmanned aerial vehicle can reach the given fixed value of the motor speed can also be tested through step 3.

[0136] In summary, the test example is verified by reverse derivation to prove that the method of the present application can test whether the unmanned aerial vehicle can work normally and accurately reach the given performance indicators such as the deflection angle, the lift and the motor speed.

[0137] The principles and implementation manners of the present application are described by applying specific examples in the present application. The above example is only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, the specific implementation manners and application ranges will be changed according to the idea of the present application. In summary, the content of the present application should not be understood as a limitation of the present application.

Claims

1. An unmanned aerial vehicle performance ground test verification platform, characterized by, include: The upper circular platform (5) is used to rigidly fix the multi-rotor UAV under test and make the center of gravity of the UAV coaxial with the rotation center of the upper circular platform; A cross-shaped universal joint (6) is provided between the upper truncated cone and the intermediate rod, giving the upper truncated cone the ability to deflect around the X and Y axes with two degrees of freedom. The middle rod (7) is fixed at the upper end to the cross shaft universal joint, and at the lower end is connected to the dynamic force sensor (9) through the dynamic force sensor pressure head (8). The dynamic force sensor (9) is used to collect the overall lift of the UAV in real time. No fewer than three sets of guide rail units, each set of guide rail units including: The guide rail (22) and guide rail slider (23) are used to provide radial translation guidance; The grating ruler slide rail (26) and the grating ruler slider (25) are used to measure the slider displacement in real time; The upper rod (282) and the lower rod (281) are connected in series with a side rod force sensor (29) to obtain the axial force of the rod; The upper ball hinge (272) and the lower ball hinge (271) respectively connect the top of the upper side rod to the upper truncated cone and the bottom of the lower side rod to the slider of the grating ruler, forming a spatial spherical pair; The control and data acquisition system is used to synchronously acquire real-time signals from the dynamic force sensor, side rod force sensor, and grating ruler, and calculate the spatial deflection angle of the upper truncated cone, the overall lift, and the lift distribution of each rotor, thereby completing the performance verification of the UAV in an indoor environment. 2.The UAV performance ground test verification platform of claim 1, wherein, It also includes a lower base (1) for overall support and fixing to the ground; a support frame (21) fixed to the lower base; the not less than three sets of guide rail units are evenly distributed along the circumference between the lower base and the upper truncated cone, and the lower base (1) is also fixed with the dynamic force sensor pressure head (8).

3. A UAV performance ground test verification method, using the platform of claim 1 or 2, characterized in that, Includes the following steps: S1: Build a verification platform and model it; S2: Fixed installation of the drone; control of the drone with a remote controller; test the drone's deflection angle based on the slider movement distance of the guide rail unit. S3: Based on the detection data from the dynamic force sensor and each guide rail unit, calculate the component force perpendicular to the rotor rotation plane, and calculate the resultant force as the overall lift of the UAV; S4: Control the UAV to be in a static state at any angle. Based on the overall slope angle and overall yaw angle of the UAV, solve for the pitch angle and roll angle, and further calculate the pitch moment and roll moment. Based on the hybrid control logic, select the standardized solution that meets the preset standard from the solution set of motor speeds to obtain the lift of a single motor of the UAV, and further obtain the motor speed.

4. The method for ground testing and verification of UAV performance according to claim 3, characterized in that, In step S1, modeling the verification platform specifically involves defining a coordinate system in the initial horizontal state of the upper frustum. The origin of the coordinate system is the center of rotation of the universal joint. ,point The direction of the line connecting the center of the ball to the upper ball hinge is Positive axis direction shaft edge Rotate the point horizontally counterclockwise by 90 degrees. The positive direction of the axis, the vertical direction is Positive direction of the axis.

5. The method for ground testing and verification of UAV performance according to claim 4, characterized in that, S2 includes: S2.1: Fix the drone in the preset position on the upper circular platform, with the drone's center of gravity aligned with point [missing information]. On the same vertical line, the nose points Positive direction of the axis; S2.2: Use the remote controller to apply a basic lift to the drone rotor and keep it constant, then control the drone's pitch and roll. S2.3: Measure the slider movement distance of each guide rail unit and calculate the slope angle of each guide rail unit direction; combine the obtained slope angle of each guide rail unit direction with the yaw angle of each guide rail unit direction, fit the upper frustum plane after pose transformation and solve the plane equation to obtain the overall slope angle and yaw angle of the plane.

6. The method for ground testing and verification of UAV performance according to claim 5, characterized in that, In S2.3, the slope angle of each guide rail unit is calculated as follows: By combining the vertical distance from the center of each lower ball hinge to the axis of the middle rod in the initial horizontal state with the slider movement distance of the guide rail unit, the length of the line segment connecting point O and the center of each lower ball hinge is calculated. Then, the angle between the upper frustum and the center of the middle rod after the pose transformation is further solved. ; According to the above By determining the positional relationship between the slope angles of each guide rail unit and the slope angles of the guide rail units, which are complementary angles, the slope angles of each guide rail unit can be obtained.

7. The method for ground testing and verification of UAV performance according to claim 6, characterized in that, S3 includes: Taking the center of the upper ball hinge of each guide rail unit as a fixed point and the center of the upper rod as the direction, a straight line is determined; the drawn straight line is combined with the plane equation to calculate the angle between each upper rod and the plane; this angle is combined with the detected force of each rod force sensor to calculate the lift force perpendicular to the plane measured by each guide rail unit; the lift force perpendicular to the plane measured by the dynamic force sensor is solved using the overall slope angle of the plane and the detected force of the dynamic force sensor. The overall lift of the UAV is obtained by calculating the resultant force of the lift of all guide rail units and the lift obtained from the dynamic force sensor.

8. The method for ground testing and verification of UAV performance according to claim 7, characterized in that, The force detected by each side rod force sensor The specific calculation method is as follows: Apply a force perpendicular to the upper frustum along the center of each upper ball hinge. ,get and The included angle ; The angle between the center of each upper rod and the normal vector of the upper frustum after pose transformation is denoted as . ; and They are vertical angles, hence we get .

9. The method for ground testing and verification of UAV performance according to claim 8, characterized in that, S4 includes: Under the control of the UAV in a static state at any angle, the pitch angle and roll angle are solved based on the mapping relationship between the pitch angle, roll angle and the overall bank angle and overall yaw angle of the UAV; further, the pitch moment is calculated through the pitch angle and the roll moment is calculated through the roll angle. Combining the drone's own hybrid control logic and constant coefficients, the pitch control quantity is calculated based on the pitch moment, the roll control quantity is calculated based on the roll moment, and the overall lift is divided into the basic lift allocated to each motor. Based on the hybrid control logic, standardized solutions that meet the preset standards are selected from the solution set of motor speeds to obtain the lift of a single motor of the UAV, and then the motor speed is obtained.

10. A ground-based performance testing and verification method for unmanned aerial vehicles (UAVs) according to claim 3, characterized in that, Also includes: S5: Place the verification platform in a controllable test environment and accurately simulate various complex external scenarios to capture the drone's deflection angle, lift, and operation data in real time for specific working conditions.

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