A comprehensive test system and method for aircraft wheel performance

Abstract

A system and method for comprehensive testing of aircraft wheel performance, belonging to the technical field of comprehensive testing of aircraft wheels. The system and method for comprehensive testing of aircraft wheel performance include a transport unit, a loading unit, a support unit, a clamping unit and a data acquisition and processing unit. The data acquisition and processing unit include a pressure sensor, a displacement sensor, a lower computer and an upper computer. The system and method for comprehensive testing of aircraft wheel performance can be used to perform wheel brake performance tests and wheel tire static / dynamic stiffness tests. The system and method for comprehensive testing of aircraft wheel performance are suitable for comprehensive testing of aircraft wheels in various application scenarios, with full functions, high precision and a wide range of applications.

Description

Technical Field

[0001] The invention relates to the technical field of comprehensive testing of aircraft wheels, and in particular to a system and method for comprehensive testing performance of aircraft wheels. Background Art

[0002] At present, the aircraft wheel brake test platform uses the electric drum to directly contact the wheel or add a counterweight block at the end of the lever arm structure to simulate the braking torque when the wheel brakes, so as to complete the task of testing the wheel brake performance. It can only be tested under laboratory conditions and is powerless for test scenarios in the final assembly state and the use state. In addition, due to the lack of high-precision measurement modules, control strategies, signal processing and data analysis functions, it does not have the ability to test the static stiffness and dynamic stiffness performance of wheels and tires.

[0003] In summary, the existing system has problems such as single function, low test accuracy and poor adaptability, and can no longer meet the needs of comprehensive performance testing of modern aircraft wheels. Summary of the invention

[0004] In order to solve the technical problems existing in the prior art, the present invention provides a system and method for comprehensive testing of aircraft wheel performance, which is suitable for comprehensive testing of aircraft wheels in various application scenarios, has full functions, high precision and a wide range of applications.

[0005] In order to achieve the above object, the technical solution of the present invention is:

[0006] An aircraft wheel performance comprehensive testing system, comprising:

[0007] A transport unit comprising a base platform;

[0008] A loading unit, comprising a servo electric cylinder and a loading cantilever sequentially arranged above the base platform;

[0009] A supporting unit, which is arranged above the basic platform and is used to support the loading cantilever;

[0010] a clamping unit, which is disposed at the front end of the loading cantilever and is used to clamp the aircraft wheel; and

[0011] The data acquisition and processing unit includes a pressure sensor, a lower computer and a host computer; the pressure sensor is arranged between the servo electric cylinder and the loading cantilever, collects the output force of the servo electric cylinder and sends it to the lower computer, the lower computer obtains the loading torque loaded on the wheel tire according to the output force of the servo electric cylinder, and sends it to the host computer for display and storage; the host computer is connected to the servo electric cylinder for controlling the operation of the servo electric cylinder.

[0012] Furthermore, the data acquisition and processing unit also includes a displacement sensor arranged on the servo electric cylinder, the displacement sensor collects the extension length of the servo electric cylinder and sends it to the lower computer, the lower computer obtains the rotational displacement of the wheel tire relative to its own axis based on the extension length of the servo electric cylinder, and sends it to the upper computer for display and storage.

[0013] Furthermore, the basic platform is provided with Mecanum wheels for driving the movement thereof, and the basic platform is also provided with foot supports for adjusting the height thereof.

[0014] Furthermore, the support unit includes a support column and a support seat which are sequentially arranged above the basic platform, and the support seat supports the middle part of the loading cantilever.

[0015] Furthermore, the bottom end of the servo electric cylinder is connected to the base platform through a hinge support, the top end of the servo electric cylinder is connected to the lower surface of the pressure sensor through a hinge support, and the upper surface of the pressure sensor is vertically fixedly connected to the rear end of the loading cantilever.

[0016] Furthermore, the clamping unit includes a clamping member base fixedly connected to the front end of the loading cantilever, and the clamping member base is connected to the front clamping member through a front rotating support arm and is connected to the rear clamping member through a rear rotating support arm; the ends of the front clamping member and the rear clamping member are provided with fastening shafts, and the front clamping member and the rear clamping member hold the machine wheel and clamp it through the fastening shafts.

[0017] Furthermore, the clamping member base is vertically fixedly connected to the front end of the loading cantilever.

[0018] Preferably, the fastening shaft is a shaft with a thread at one end, and the threaded end of the fastening shaft cooperates with the threads at the ends of the front clamping member and the rear clamping member.

[0019] A method for comprehensive testing of aircraft wheel performance, using the above-mentioned comprehensive testing system for aircraft wheel performance to test wheel brake performance, comprises the following steps:

[0020] S1. Initial positioning: Move the clamping unit to the rear of the wheel through the transport unit;

[0021] S2. Precise positioning: manually lift the front clamping part to form an open state of the front clamping part and the rear clamping part; move the transport unit forward to make the front clamping part cross over the top of the wheel and then put it down, so that the front clamping part and the rear clamping part form a holding state for the wheel; the transport unit drives the clamping unit to move so that the inner contours of the front clamping part and the rear clamping part fit the outer contour of the wheel;

[0022] S3, clamping the machine wheel: tighten the tightening shaft so that the front clamping part and the rear clamping part clamp the machine wheel to form a stable hold on the machine wheel;

[0023] S4, Loading preparation: Level the foundation platform through the anchor support;

[0024] S5, loading: the upper computer controls the servo electric cylinder to extend, and applies torque to the center of the wheel through the loading cantilever. The pressure sensor measures the output force of the servo electric cylinder in real time and sends it to the lower computer. The lower computer obtains the loading torque loaded on the wheel tire according to the output force of the servo electric cylinder, and sends it to the upper computer for display and storage;

[0025] The lower computer also processes the loading torque applied to the wheel tire as follows: when the loading torque reaches the set test torque value, the lower computer sends a signal to the upper computer, and the upper computer controls the servo electric cylinder to maintain the current output force and continue to load for the set test time;

[0026] During the loading process, observe whether the wheel and the clamping unit move: if the wheel and the clamping unit do not move, the wheel braking performance is normal; if the wheel and the clamping unit move, the wheel braking performance is abnormal and needs to be repaired.

[0027] A method for comprehensive testing of aircraft wheel performance, using the above-mentioned comprehensive testing system for aircraft wheel performance to perform static / dynamic stiffness testing of wheel tires, comprises the following steps:

[0028] Step 1: Initial positioning: Move the clamping unit to the rear of the wheel through the transport unit;

[0029] Step 2: Precise positioning: Manually lift the front clamping piece to form an open state of the front clamping piece and the rear clamping piece; move the transport unit forward to make the front clamping piece cross over the top of the wheel and then put it down, so that the front clamping piece and the rear clamping piece are in a holding state for the wheel; the transport unit drives the clamping unit to move so that the inner contours of the front clamping piece and the rear clamping piece fit the outer contour of the wheel;

[0030] Step 3: Clamp the machine wheel: tighten the tightening shaft so that the front clamping part and the rear clamping part clamp the machine wheel;

[0031] Step 4: Loading preparation: Level the foundation platform and loading cantilever through the anchor support, take the horizontal position of the loading cantilever as the loading zero position, and enter the loading preparation state;

[0032] Step 5, loading: The host computer controls the servo electric cylinder to work, the input force is set to a random wave, and the servo electric cylinder applies torque to the center of the wheel through the loading cantilever;

[0033] During the loading process, the pressure sensor measures the output force of the servo electric cylinder in real time and sends it to the lower computer. The lower computer obtains the loading torque loaded on the wheel tire according to the output force of the servo electric cylinder, and sends it to the upper computer for display and storage; at the same time, the displacement sensor collects the extension length of the servo electric cylinder and sends it to the lower computer. The lower computer obtains the rotational angular displacement of the wheel tire according to the extension length of the servo electric cylinder, and sends it to the upper computer for display and storage;

[0034] The rotational angular displacement of the wheel tire is obtained by:

[0035]

[0036] Where θ is the rotational angular displacement of the wheel tire; l 1 The distance from the center of the wheel to the top hinge point of the servo electric cylinder; l 2 is the distance from the center of the wheel to the hinge point at the bottom of the servo electric cylinder; l is the real-time length of the servo electric cylinder; l 0 is the initial length of the servo electric cylinder; O x It is the top hinge point of the servo electric cylinder when it is in the extended state; O 1 is the wheel center; 4 It is the top hinge point of the servo electric cylinder in the initial state; O 5 It is the bottom hinge point of the servo electric cylinder; O 2 The wheel center O 1 The foot of the perpendicular to the horizontal centerline of the loading cantilever; O 3 The top hinge point O of the servo electric cylinder in the initial state 4 The foot of the perpendicular to the horizontal centerline of the loading cantilever;

[0037] The host computer records the loading moment M loaded on the wheel tire and the rotational angular displacement θ of the wheel tire in the time domain, regards the system input as the rotational angular displacement θ of the wheel tire, and the system output as the loading moment M loaded on the wheel tire, and adopts the system identification method to identify the frequency response function of the system; the dynamic stiffness of the wheel tire is the frequency response function of the rotational angular displacement θ of the wheel tire as the input and the loading moment M loaded on the wheel tire as the output; the amplitude-frequency curve of the system frequency response function is the dynamic stiffness curve of the wheel tire; the point on the dynamic stiffness curve where the excitation frequency is 0 Hz is the static stiffness point.

[0038] Beneficial effects of the present invention:

[0039] 1) The present invention has the characteristics of high flexibility, high precision, full functions and wide application range. It provides a compact and ideal integrated solution for comprehensive performance testing of aircraft wheels in various application scenarios. It is a breakthrough in the traditional single wheel brake performance testing system and can be widely used in wheel brake performance and wheel tire static / dynamic stiffness performance testing.

[0040] 2) The loading unit of the present invention adopts a high-precision servo electric cylinder and a pressure sensor, which greatly improves the test accuracy and range; the high-precision loading module and measurement module, together with the data acquisition and processing unit, can not only complete the wheel brake performance test, but also be used for the static stiffness and dynamic stiffness test of the wheel tire;

[0041] 3) The present invention can not only perform wheel braking performance tests under laboratory conditions, but also perform aircraft wheel braking performance tests in multiple scenarios such as aircraft assembly and use, thereby completing the test task;

[0042] 4) The present invention has a simple and intelligent structure, good versatility, good test effect, and convenient operation. It can be widely used in wheel brake testing during aircraft maintenance, and is particularly suitable for solving wheel brake testing of helicopters and fixed-wing aircraft;

[0043] 5) The Mecanum wheel trolley used in the present invention has the advantages of good structural rigidity, high control accuracy, fast response speed, maximum flexibility and free maneuverability, etc., so that the present invention has better control performance indicators, a wider range of test objects, and can obtain better test results.

[0044] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a schematic diagram of a front view of an aircraft wheel performance comprehensive testing system provided by an embodiment of the present invention;

[0046] Figure 2 is a schematic top view of an aircraft wheel performance comprehensive testing system provided by an embodiment of the present invention;

[0047] Figure 3 is a left schematic diagram of an aircraft wheel performance comprehensive testing system provided by an embodiment of the present invention;

[0048] Figure 4 is a simplified structural diagram of a computer wheel tire rotational angular displacement provided by an embodiment of the present invention;

[0049] Figure 5 It is a schematic diagram of a dynamic stiffness curve of a wheel tire provided in an embodiment of the present invention.

[0050] The reference numerals in the drawings of the specification include:

[0051] 1-Servo electric cylinder, 2-pressure sensor, 3-loading cantilever, 4-support column, 5-support seat, 6-clamp base, 7-front rotating arm, 8-front clamp, 9-fastening shaft, 10-Mecanum wheel, 11-ground support, 12-power battery, 13-basic platform, 14-rear rotating arm, 15-rear clamp. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0053] In the description of the present invention, it is necessary to understand that the terms "longitudinal", "lateral", "vertical", "up", "down", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0054] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0055] In order to solve the problems existing in the prior art, such as Figures 1 to 5 As shown, the present invention provides an aircraft wheel performance comprehensive testing system, comprising:

[0056] A transport unit comprising a base platform 13;

[0057] A loading unit, comprising a servo electric cylinder 1 and a loading cantilever 3 which are sequentially arranged above a base platform 13;

[0058] A support unit, which is arranged above the base platform 13 and is used to support the loading cantilever 3;

[0059] A clamping unit, which is disposed at the front end of the loading cantilever 3 and is used to clamp the aircraft wheel; and

[0060] The data acquisition and processing unit includes a pressure sensor 2, a lower computer and a host computer; the pressure sensor 2 is arranged between the servo electric cylinder 1 and the loading cantilever 3, collects the output force of the servo electric cylinder 1 and sends it to the lower computer, and the lower computer obtains the loading torque loaded on the wheel tire according to the output force of the servo electric cylinder 1, and sends it to the host computer for display and storage; the host computer is connected to the servo electric cylinder 1 for controlling the operation of the servo electric cylinder 1.

[0061] In the present invention, the data acquisition and processing unit also includes a displacement sensor arranged on the servo electric cylinder 1. The displacement sensor collects the extension length of the servo electric cylinder 1 and sends it to the lower computer. The lower computer obtains the rotational displacement of the wheel tire relative to its own axis based on the extension length of the servo electric cylinder 1, and sends it to the upper computer for display and storage.

[0062] like Figures 1 to 3 As shown, the basic platform 13 is provided with Mecanum wheels 10 for driving the movement thereof, and the basic platform 13 is also provided with anchor supports 11 for adjusting the height thereof. In this embodiment, four Mecanum wheels 10 are provided, and the Mecanum wheels 10 are connected to a power battery 12, and the power battery 12 supplies power to the Mecanum wheels 10. Three anchor supports 11 are provided. When the test system needs to be moved, the anchor supports 11 are retracted upward, and the test system is moved to a set position through the Mecanum wheels 10. After reaching the set position, the anchor supports 11 extend downward to support the ground, and support the basic platform 13 and the Mecanum wheels 10, so as to ensure the stable operation of the test system.

[0063] like Figures 1 to 3 As shown, the support unit includes a support column 4 and a support seat 5 which are sequentially arranged above the basic platform 13. The support seat 5 supports the middle part of the loading cantilever 3. Specifically, the lower end of the support column 4 is fixed on the basic platform 13, and the upper end of the support column 4 is fixedly connected to the lower end of the support seat 5. The support seat 5 is used to support the loading cantilever 3 and the clamping unit. As a preferred embodiment, a pad is arranged on the top of the support seat 5 to improve the service life, and the pad can be a resin pad.

[0064] In the present invention, the bottom end of the servo electric cylinder 1 is connected to the base platform 13 through a hinge support, the top end of the servo electric cylinder 1 is connected to the lower surface of the pressure sensor 2 through a hinge support, and the upper surface of the pressure sensor 2 is vertically fixedly connected to the rear end of the loading cantilever 3 to ensure that the pressure sensor 2 collects the force vertically loaded to the loading cantilever 3, thereby improving the accuracy of the test results.

[0065] In the present invention, the clamping unit includes a clamping member base 6 fixedly connected to the front end of the loading cantilever 3, the clamping member base 6 is connected to the front clamping member 8 through the front rotating arm 7, and is connected to the rear clamping member 15 through the rear rotating arm 14; the ends of the front clamping member 8 and the rear clamping member 15 are provided with a fastening shaft 9, the front clamping member 8 and the rear clamping member 15 hold the machine wheel and clamp through the fastening shaft 9, specifically, the clamping member base 6 is connected to the front rotating arm 7 and the rear rotating arm 14 through a pin shaft, the front rotating arm 7 is fixedly connected to the front clamping member 8, and the rear rotating arm 14 is fixedly connected to the rear clamping member 15. The clamping member base 6 is vertically fixedly connected to the front end of the loading cantilever 3, which cooperates with the vertical connection between the pressure sensor 2 and the rear end of the loading cantilever 3, further ensuring that the pressure sensor 2 collects the force vertically loaded to the loading cantilever 3, thereby improving the accuracy of the test results.

[0066] As a preferred embodiment, the fastening shaft 9 is a shaft with a thread at one end, and the threaded end of the fastening shaft 9 cooperates with the threads at the ends of the front clamping member 8 and the rear clamping member 15 to achieve the clamping of the front clamping member 8 and the rear clamping member 15. The fastening shaft 9 can adjust the clamping tightness according to different tire pressures, thereby improving the versatility and clamping effect of the test system.

[0067] When the present invention is used, according to the condition of the aircraft wheel being tested, suitable structures such as the servo electric cylinder 1, the pressure sensor 2 and the displacement sensor are selected, and the application range is wide.

[0068] The working principle of the aircraft wheel performance comprehensive testing system of the present invention is as follows:

[0069] A freely movable positioning mechanism is formed by two sets of Mecanum wheels 10, three anchor supports 11, a power battery 12 for powering the Mecanum wheels 10, and a base platform 13; a semi-physical simulation test mechanism composed of a lever structure of an actual wheel, a pressure sensor 2, and a servo electric cylinder 1 can be used to continuously perform multiple wheel brake tests;

[0070] The test system can be freely moved in the X and Y planes by two sets of Mecanum wheel 10 trolleys; accurate torque is applied to the test object by controlling the servo electric cylinder 1, thus completing the wheel brake test;

[0071] First, the aircraft wheel to be tested is lifted and braked by its own brake system; the transport unit moves the comprehensive test system to the working area through the Mecanum wheel 10; the front clamp 8 and the rear clamp 15 are manually opened to clamp the aircraft wheel, and the servo electric cylinder 1 is started. The servo electric cylinder 1 slowly applies a set torque to the aircraft wheel to perform a comprehensive test of the aircraft wheel performance.

[0072] The present invention also provides an aircraft wheel performance comprehensive test method, which uses the above-mentioned aircraft wheel performance comprehensive test system to perform a wheel brake performance test, comprising the following steps:

[0073] S1. Initial positioning: Move the clamping unit to the rear of the wheel through the transport unit;

[0074] Specifically, four (two groups) of Mecanum wheels 10 are placed on the ground, and the positions can be adjusted in any direction on the plane;

[0075] S2, precise positioning: manually lift the front clamping member 8, so that the front clamping member 8 and the rear clamping member 15 are in an open state; the transport unit moves forward, so that the front clamping member 8 crosses over the top of the wheel and then is lowered, so that the front clamping member 8 and the rear clamping member 15 are in a holding state for the wheel; the transport unit drives the clamping unit to move, so that the inner contours of the front clamping member 8 and the rear clamping member 15 fit the outer contour of the wheel;

[0076] Specifically, the front clamping member 8 is rotated around the clamping member base 6 by the front rotating support arm 7, so that the front clamping member 8 and the rear clamping member 15 are opened; the position of the test system on the ground is adjusted by the Mecanum wheel 10, the front clamping member 8 is placed over the wheel and then lowered, and the front clamping member 8 and the rear clamping member 15 form a hold for the wheel; the system position is fine-tuned by the Mecanum wheel 10 until the inner contours of the front clamping member 8 and the rear clamping member 15 are closely fitted with the outer contour of the wheel, so as to provide clamping conditions to meet the test requirements;

[0077] S3, clamping the machine wheel: tighten the tightening shaft 9 so that the front clamping member 8 and the rear clamping member 15 clamp the machine wheel to form a stable hold on the machine wheel;

[0078] S4, loading preparation: leveling the base platform 13 through the anchor support 11;

[0079] Specifically, the basic platform 13 is supported and leveled by three anchor supports 11, and enters the loading preparation state. When leveling the basic platform 13, the level ruler is used to assist, and the leveling is achieved in conjunction with the rotation of the machine wheel and the hinged seats at both ends of the servo electric cylinder 1. Although the position of the servo electric cylinder 1 changes, the pressure sensor 2 vertically fixedly connected to the loading cantilever 3 collects a force that is always perpendicular to the loading cantilever 3;

[0080] S5, loading: the upper computer controls the servo electric cylinder 1 to extend, and applies a torque to the center of the wheel through the loading cantilever 3. The pressure sensor 2 measures the output force of the servo electric cylinder 1 in real time and sends it to the lower computer. The lower computer obtains the loading torque loaded on the wheel tire according to the output force of the servo electric cylinder 1, and sends it to the upper computer for display and storage;

[0081] The lower computer also processes the loading torque applied to the wheel tire as follows: when the loading torque reaches the set test torque value, the lower computer sends a signal to the upper computer, and the upper computer controls the servo electric cylinder 1 to maintain the current output force and continue to load for the set test time;

[0082] During the loading process, observe whether the wheel and the clamping unit move: if the wheel and the clamping unit do not move, the wheel braking performance is normal; if the wheel and the clamping unit move, the wheel braking performance is abnormal and needs to be repaired.

[0083] In the present invention, the servo electric cylinder 1 applies force to the rear end of the loading cantilever 3, and forms the brake torque required for the wheel brake performance test at the center of the wheel through the loading cantilever 3. The output force of the servo electric cylinder 1 is measured in real time by the pressure sensor 2, forming a continuous, linear, and high-precision loading process of the brake torque. The lower computer performs the following calculations through the built-in program: the output force of the servo electric cylinder 1 is multiplied by the lever arm to obtain the loading torque loaded on the wheel tire. Since the upper surface of the pressure sensor 2 is vertically fixedly connected to the rear end of the loading cantilever 3, the clamping member base 6 is vertically fixedly connected to the front end of the loading cantilever 3, and the distance between the two fixed connection points is the lever arm, and the lever arm remains unchanged. When observing whether the wheel and the clamping unit move, a laser pen can be used to assist in observation. After leveling the basic platform 13, the current position of the wheel and the clamping unit is determined by the laser pen, which is the original position. In the process of loading the torque, it is sufficient to observe whether the wheel and the clamping unit move relative to the original position. The aircraft wheel and its built-in brake system of the present invention all adopt the structure on the actual aircraft. The braking torque of the wheel is provided by the test system to form a semi-physical simulation test system. The test results are consistent with the actual data and have high accuracy.

[0084] When the present invention actually conducts a wheel brake performance test, under laboratory conditions, the wheel can be equipped with a dedicated supporting and fixing device to form a fixed end to complete the loading process of steps S1 to S5; when the aircraft is assembled or in use, the aircraft can be lifted up with a universal jack to form a fixed end to complete the loading process of steps S1 to S5.

[0085] The present invention also provides an aircraft wheel performance comprehensive testing method, which uses the above-mentioned aircraft wheel performance comprehensive testing system to perform wheel tire static / dynamic stiffness testing, comprising the following steps:

[0086] Step 1: Initial positioning: Move the clamping unit to the rear of the wheel through the transport unit;

[0087] Step 2: Precise positioning: Manually lift the front clamping member 8 to form an open state of the front clamping member 8 and the rear clamping member 15; move the transport unit forward to make the front clamping member 8 cross over the top of the wheel and then put it down, so that the front clamping member 8 and the rear clamping member 15 are in a holding state for the wheel; the transport unit drives the clamping unit to move, so that the inner contours of the front clamping member 8 and the rear clamping member 15 fit the outer contour of the wheel;

[0088] Step 3: Clamp the machine wheel: tighten the tightening shaft 9 so that the front clamping member 8 and the rear clamping member 15 clamp the machine wheel;

[0089] Specifically, in the wheel and tire static / dynamic stiffness test, the first to third steps are exactly the same as steps S1 to S3 of the wheel brake performance test;

[0090] Step 4, loading preparation: level the basic platform 13 and the loading cantilever 3 through the anchor support 11, take the horizontal position of the loading cantilever 3 as the loading zero position, and enter the loading preparation state;

[0091] Specifically, the basic platform 13 and the loading cantilever 3 are supported and leveled by three anchor supports 11, and the loading preparation state is entered. When leveling the basic platform 13 and the loading cantilever 3, the leveling is assisted by a level ruler, and the leveling is achieved in conjunction with the rotation of the machine wheel and the articulated seats at both ends of the servo electric cylinder 1. Although the position of the servo electric cylinder 1 changes, the pressure sensor 2 vertically fixedly connected to the loading cantilever 3 collects a force that is always perpendicular to the loading cantilever 3;

[0092] Step 5, loading: The host computer controls the servo electric cylinder 1 to work, and the input force is set to a random wave. The servo electric cylinder 1 applies a torque to the center of the wheel through the loading cantilever 3;

[0093] During the loading process, the pressure sensor 2 measures the output force of the servo electric cylinder 1 in real time and sends it to the lower computer. The lower computer obtains the loading torque loaded on the wheel tire according to the output force of the servo electric cylinder 1, and sends it to the upper computer for display and storage. At the same time, the displacement sensor collects the extension length of the servo electric cylinder 1 and sends it to the lower computer. The lower computer obtains the rotational angular displacement of the wheel tire according to the extension length of the servo electric cylinder 1, and sends it to the upper computer for display and storage.

[0094] The rotational angular displacement of the wheel tire is obtained as follows:

[0095]

[0096] In the formula, Figure 4 As shown, θ is the rotational angular displacement of the wheel tire, that is, ∠O x O 1 O 5 With ∠O 4 O 1 O 5The difference; l 1 is the distance from the center of the wheel to the top hinge point of the servo electric cylinder 1, which is a constant value; l 2 is the distance from the center of the wheel to the hinge point at the bottom of the servo electric cylinder 1, which is a constant value; l is the real-time length of the servo electric cylinder 1, that is, the distance from the hinge point at the bottom to the hinge point at the top of the servo electric cylinder 1 when in the extended state, which is collected in real time by the built-in displacement sensor of the servo electric cylinder 1; l 0 is the initial length of the servo electric cylinder 1, that is, the distance from the bottom hinge point to the top hinge point of the servo electric cylinder 1 in the initial state, which is a constant value; x The top hinge point of the servo electric cylinder 1 in the extended state; O 1 is the wheel center; 4 O is the top hinge point of the servo electric cylinder 1 in the initial state; 5 It is the bottom hinge point of the servo electric cylinder 1; 2 The wheel center O 1 To the foot of the horizontal center line of the loading cantilever 3; O 3 The top hinge point O of the servo electric cylinder 1 in the initial state 4 The foot of the perpendicular to the horizontal centerline of the loading cantilever 3, point O 3 , O 4 and O 5 In the same straight line;

[0097] Specifically, the rotational angular displacement of the wheel tire is caused by the deformation of the tire under the action of the loading torque, which results in the rotational angular displacement relative to the center of the wheel on a macro scale, and at this time the wheel itself has no relative rotation relative to its center. The calculation idea of ​​the rotational angular displacement of the wheel tire is: the relative position relationship between the front clamping member 8, the rear clamping member 15, the front rotating arm 7, the rear rotating arm 14, the clamping member base 6, the loading cantilever 3 and the pressure sensor 2 remains unchanged during the loading process; the initial state of the loading cantilever 3 is horizontal; the center of the wheel and the bottom hinge support of the servo electric cylinder 1 are fixed points during the loading process, and their spatial positions can be measured; the top hinge support of the servo electric cylinder 1 is a fixed point, and its initial spatial position can be measured; the rotational angular displacement of the line connecting the center of the wheel and the center of the lower surface of the pressure sensor 2 during the loading process is the rotational angular displacement of the wheel tire.

[0098] The host computer records the loading moment M and the rotational angular displacement θ of the wheel tire in the time domain, and regards the system input as the rotational angular displacement θ of the wheel tire, and the system output as the loading moment M loaded on the wheel tire. The frequency response function of the system is identified by the system identification method; the dynamic stiffness of the wheel tire is the frequency response function of the rotational angular displacement θ of the wheel tire as the input and the loading moment M loaded on the wheel tire as the output; the amplitude-frequency curve of the system frequency response function is the dynamic stiffness curve of the wheel tire; the point on the dynamic stiffness curve with an excitation frequency of 0 Hz is the static stiffness point.

[0099] Specifically, the dynamic stiffness test of the wheel tire uses a random wave excitation signal. According to the definition of dynamic stiffness, when the system output is force and the input is displacement, the corresponding frequency response function is the dynamic stiffness of the system. The dynamic stiffness characteristics of the system are usually given by the dynamic stiffness characteristic curve. The dynamic stiffness characteristic curve intuitively shows the corresponding relationship between the stiffness of the system and the frequency of the excitation signal, as shown in the attached figure. Figure 5 The dynamic stiffness curve of the wheel and tire is shown. On the dynamic stiffness curve of the wheel and tire, the point with an excitation frequency of 0 Hz is the static stiffness point of the wheel and tire.

[0100] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A comprehensive test method for aircraft wheel performance, used for testing the static / dynamic stiffness of aircraft wheel tires, characterized in that: The steps include: Step 1: Initial positioning: Move the clamping unit to the rear of the wheel through the transport unit; Step 2: Precise positioning: Manually lift the front clamp, move the transport unit forward, make the front clamp cross over the wheel and then put it down, so that the front clamp and the rear clamp form a holding state for the wheel; Step 3: Clamp the machine wheel: tighten the tightening shaft so that the front clamping part and the rear clamping part clamp the machine wheel; Step 4: Loading preparation: Level the foundation platform and loading cantilever through the anchor support, and use the horizontal position of the loading cantilever as the loading zero position; Step 5, loading: The host computer controls the servo electric cylinder to work, the input force is set to a random wave, and the servo electric cylinder applies torque to the center of the wheel through the loading cantilever; During the loading process, the pressure sensor measures the output force of the servo electric cylinder in real time and sends it to the lower computer. The lower computer obtains the loading torque loaded on the wheel tire according to the output force of the servo electric cylinder, and sends it to the upper computer for display and storage; at the same time, the displacement sensor collects the extension length of the servo electric cylinder and sends it to the lower computer. The lower computer obtains the rotational angular displacement of the wheel tire according to the extension length of the servo electric cylinder, and sends it to the upper computer for display and storage; The rotational angular displacement of the wheel tire is obtained by: In the formula, is the rotational angular displacement of the wheel tire; It is the distance from the center of the wheel to the hinge point at the top of the servo electric cylinder; It is the distance from the center of the wheel to the hinge point at the bottom of the servo electric cylinder; is the real-time length of the servo electric cylinder; is the initial length of the servo electric cylinder; It is the top hinge point of the servo electric cylinder in the extended state; is the wheel center; It is the top hinge point of the servo electric cylinder in the initial state; It is the bottom hinge point of the servo electric cylinder; Wheel center The foot of the perpendicular to the horizontal centerline of the loading cantilever; The top hinge point of the servo electric cylinder in the initial state The foot of the perpendicular to the horizontal centerline of the loading cantilever; The host computer records the loading torque loaded on the wheel tire in the time domain and the angular displacement of the wheel and tire , the input of the aircraft wheel performance comprehensive test system is the rotational angular displacement of the wheel tire The output of the aircraft wheel performance comprehensive test system is the loading torque applied to the wheel tire. The frequency response function of the aircraft wheel performance comprehensive test system is identified by using the system identification method; the dynamic stiffness of the wheel tire is the input of the rotational angular displacement of the wheel tire , the output is the loading torque applied to the wheel tire The frequency response function of the system frequency response function is the dynamic stiffness curve of the wheel tire; the point on the dynamic stiffness curve where the excitation frequency is 0Hz is the static stiffness point; Wherein, the aircraft wheel performance comprehensive testing system comprises: A transport unit comprising a base platform; A loading unit, comprising a servo electric cylinder and a loading cantilever sequentially arranged above the base platform; A supporting unit, which is arranged above the basic platform and is used to support the loading cantilever; a clamping unit, which is disposed at the front end of the loading cantilever and is used to clamp the aircraft wheel; and A data acquisition and processing unit, comprising a pressure sensor, a lower computer and an upper computer; the pressure sensor is arranged between the servo electric cylinder and the loading cantilever, collects the output force of the servo electric cylinder and sends it to the lower computer, the lower computer obtains the loading torque loaded on the wheel tire according to the output force of the servo electric cylinder, and sends it to the upper computer for display and storage; the upper computer is connected to the servo electric cylinder and is used to control the operation of the servo electric cylinder; The data acquisition and processing unit further comprises a displacement sensor disposed on the servo electric cylinder, the displacement sensor acquires the extension length of the servo electric cylinder and sends it to the lower computer, the lower computer obtains the rotational displacement of the wheel tire relative to its own axis according to the extension length of the servo electric cylinder, and sends it to the upper computer for display and storage; The basic platform is provided with Mecanum wheels for driving the basic platform to move, and the basic platform is also provided with a foot support for adjusting the height thereof; The support unit comprises a support column and a support seat which are sequentially arranged above the base platform, and the support seat supports the middle part of the loading cantilever; The bottom end of the servo electric cylinder is connected to the base platform through a hinge support, the top end of the servo electric cylinder is connected to the lower surface of the pressure sensor through a hinge support, and the upper surface of the pressure sensor is vertically fixedly connected to the rear end of the loading cantilever; The clamping unit comprises a clamping member base fixedly connected to the front end of the loading cantilever, the clamping member base is connected to the front clamping member through the front rotating arm, and is connected to the rear clamping member through the rear rotating arm; the ends of the front clamping member and the rear clamping member are provided with fastening shafts, and the front clamping member and the rear clamping member hold the machine wheel and clamp it through the fastening shaft; The clamping member base is vertically fixedly connected to the front end of the loading cantilever; The fastening shaft is a shaft with a thread at one end, and the threaded end of the fastening shaft is matched with the threads at the ends of the front clamping piece and the rear clamping piece.

Images