0-frequency modal test support system and test device

Abstract

The invention provides a 0-frequency modal test supporting system and a test device, and belongs to the field of unmanned aerial vehicle tests.The supporting system comprises a suspension supporting module, a force feedback module, an inertia force compensation module and a controller, liquid and a suspension part suspended in the liquid are arranged in the suspension supporting module, and the suspension part is used for being in rigid connection with a tested piece; the force feedback module is used for being connected with a tested piece and measuring inertia force generated by vibration of the suspension part; the inertia force compensation module is used for being connected with a tested piece and providing compensation force for counteracting the inertia force; the controller is used for controlling the inertia force compensation module to provide compensation force according to the inertia force. The suspension supporting module can balance the gravity of the tested piece and can be matched with the compensation force provided by the compensation vibration exciter, so that the tested piece can be always in a follow-up balance state and has an extremely low and even zero-frequency vibration state, and the real running state of the tested piece suspended in the air or liquid can be completely simulated, thereby obtaining accurate modal parameters.

Description

Technical Field

[0001] The present invention belongs to the field of unmanned aerial vehicle testing, and more specifically, relates to a zero-frequency modal test support system and a test device. Background Art

[0002] At present, some types of UAVs are characterized by large size, low stiffness, and very low structural natural frequency. During modal tests, the support frequency has a great influence on the modal test results. The support system built by traditional methods is difficult to obtain low-frequency characteristics. During modal tests, the support system often changes the modal characteristics of the UAV, making it difficult to obtain accurate modal characteristics of the UAV. Summary of the invention

[0003] The purpose of the present invention is to provide a zero-frequency modal test support system and a test device to solve the problem that the existing support system is difficult to obtain low-frequency characteristics.

[0004] In order to achieve the above-mentioned object, in a first aspect, the present invention provides a zero-frequency modal test support system, comprising:

[0005] A suspension support module, wherein a liquid and a suspension component suspended in the liquid are provided in the suspension support module, and the suspension component is used to be rigidly connected to the test piece;

[0006] A force feedback module, the force feedback module is connected between the suspension component and the test piece and measures the inertial force generated by the vibration of the suspension component;

[0007] An inertia force compensation module, the inertia force compensation module is used to be connected to the test piece and provide a compensation force to offset the inertia force;

[0008] A controller is used to control the inertia force compensation module to provide the compensation force according to the inertia force.

[0009] Optionally, the suspension support module includes:

[0010] a container, wherein the liquid is arranged in the container;

[0011] A first rigid rod, wherein the upper end of the first rigid rod is disposed in the container and connected to the capsule, the lower end of the first rigid rod extends outside the container and is used to be connected to the test piece, and the first rigid rod is movably and hermetically connected to the container;

[0012] The suspension component is a capsule.

[0013] Optionally, the upper end of the force feedback module is connected to the lower end of the first rigid rod, and the lower end of the force feedback module is used to be connected to the test piece.

[0014] Optionally, the capsule has a streamlined shape.

[0015] Optionally, the capsule is an elliptical ellipsoid.

[0016] Optionally, the balloon is capable of adjusting volume.

[0017] Optionally, at least one of the bladder and the rigid rod is capable of adjusting weight.

[0018] Optionally, the controller is a PID controller.

[0019] Optionally, the inertial force compensation module is connected to the test piece via a second rigid rod, and a position of the inertial force compensation module corresponds to a position of the suspension support module.

[0020] In a second aspect, the present invention provides a modal test device, comprising:

[0021] At least one zero-frequency modal test support system according to the first aspect;

[0022] A vibration excitation module, wherein the vibration excitation module is used to be connected to the test piece and provide the vibration required for the modal test.

[0023] The beneficial effects of the present invention are: providing a zero-frequency modal test support system, including: a suspension support module, a force feedback module, an inertia force compensation module and a controller, wherein the suspension support module is provided with a liquid and a suspension component suspended in the liquid, and the suspension component is used to be rigidly connected to the test piece; the force feedback module is used to connect to the test piece and measure the inertia force generated by the vibration of the suspension component; the inertia force compensation module is used to connect to the test piece and provide a compensation force to offset the inertia force; the controller is used to control the inertia force compensation module to provide a compensation force according to the inertia force. The suspension support module can balance the gravity of the test piece, and cooperate with the compensation force provided by the compensation exciter, so that the test piece can always be in a dynamic balance state and have a very low or even zero frequency vibration state, which can completely simulate the actual operating state of the test piece suspended in the air or in the liquid, so as to obtain accurate modal parameters.

[0024] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0026] Figure 1 A schematic structural diagram of a zero-frequency modal test support system in Embodiment 1 of the present invention is shown.

[0027] Figure 2 A schematic structural diagram of a modal test device in Embodiment 2 of the present invention is shown.

[0028] Figure numerals in the second embodiment:

[0029] 1. Vibration excitation module; 2. Force feedback module; 3. Inertia force compensation module; 4. UAV; 5. Container; 6. Liquid; 7. Capsule; 8. First rigid rod; 9. Second rigid rod; 10. Suspension support module; 11. Test piece. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0031] Embodiment 1:

[0032] like Figure 1 As shown, this embodiment provides a zero-frequency modal test support system, including:

[0033] A suspension support module 10, wherein the suspension support module 10 is provided with a liquid 6 and a suspension component suspended in the liquid 6, and the suspension component is used to be rigidly connected to the test piece 11;

[0034] A force feedback module 2, which is connected between the suspension component and the test piece 11 and measures the inertial force generated by the vibration of the suspension component;

[0035] An inertia force compensation module 3, the inertia force compensation module 3 is used to connect with the test piece 11 and provide a compensation force to offset the inertia force;

[0036] The controller is used to control the inertia force compensation module 3 to provide compensation force according to the inertia force.

[0037] Specifically, the suspension support module 10 can balance the gravity of the test piece 11 by utilizing the suspension characteristics, and the inertial force compensation module 3 can provide a controllable force to offset the inertial force generated by the vibration of the suspension component. The suspension support module 10 cooperates with the inertial force compensation module 3 to enable the test piece 11 to always be in a dynamic equilibrium state and have a very low or even zero frequency vibration state, which can completely simulate the actual operating state of the test piece 11 suspended in the air or in the liquid 6, thereby obtaining accurate modal parameters. It is suitable for aircraft such as drones with low structural natural frequencies, and has the characteristics of low cost, simulation of actual environment, and convenient use and maintenance. The force feedback module 2, the inertial force compensation module 3 and the controller are all existing technologies, and the specific structure and working principle are not described in detail.

[0038] In this embodiment, the suspension support module 10 includes:

[0039] A container 5, wherein a liquid 6 is provided in the container 5;

[0040] A first rigid rod 8, the upper end of which is disposed in the container 5 and connected to the capsule 7, the lower end of which extends outside the container 5 and is used to be connected to the test piece 11, and the first rigid rod 8 is movably and hermetically connected to the container 5;

[0041] The suspension component is a capsule 7.

[0042] Specifically, the container 5 is used to hold the liquid 6 , and the liquid 6 provides buoyancy for the capsule 7 , so that the capsule 7 can be suspended in the liquid 6 .

[0043] Optionally, the upper end of the force feedback module 2 is connected to the lower end of the first rigid rod 8 , and the lower end of the force feedback module 2 is used to be connected to the test piece 11 .

[0044] Specifically, the force feedback module 2 is disposed between the first rigid rod 8 and the test piece 11 , and can more accurately measure the inertial force generated by the vibration of the suspension component.

[0045] Preferably, the capsule 7 has a streamlined shape.

[0046] Specifically, the streamlined capsule 7 has a low resistance characteristic, which reduces the influence of the shape of the capsule 7 on the vibration.

[0047] In this embodiment, the capsule 7 is an elliptical ellipsoid.

[0048] Optionally, the capsule 7 can be volume-adjustable.

[0049] Specifically, the volume of the bladder 7 can be adjusted by inflating or deflating, thereby adjusting the buoyancy, so that the test pieces 11 of different weights can be in a follow-up suspension state.

[0050] Optionally, at least one of the bladder 7 and the rigid rod is capable of adjusting weight.

[0051] Specifically, the capsule 7 or the rigid rod can adjust its own weight according to the weight of the test object 11 , so that the capsule 7 is always suspended in the liquid 6 , thereby enhancing the applicability to different test objects 11 .

[0052] In this embodiment, the controller is a PID controller.

[0053] The PID controller is a prior art, and its specific structure and working principle are not described in detail.

[0054] Optionally, the inertial force compensation module 3 is connected to the test piece 11 via the second rigid rod 9 , and the position of the inertial force compensation module 3 corresponds to the position of the suspension support module 10 .

[0055] Specifically, the position of the inertial force compensation module 3 corresponds to the position of the suspension support module 10 , the compensation force is easier to control, and the test piece 11 can obtain a better compensation effect.

[0056] Embodiment 2:

[0057] like Figure 2 As shown, this embodiment provides a modal test device, including:

[0058] At least one zero-frequency modal test support system in Embodiment 1;

[0059] At least one vibration excitation module 1, the vibration excitation module 1 is used to connect with the test piece and provide the vibration required for the modal test.

[0060] Specifically, the number of the zero-frequency modal test support system and the vibration excitation module 1 is set according to the structural shape of the test piece and the test requirements.

[0061] In this embodiment, the test piece is a drone 4, two zero-frequency modal test support systems are provided, and two vibration excitation modules 1 are provided. After the capsule 7 is connected to the drone 4 through the first rigid rod 8, it is placed in the liquid 6, and the liquid 6 is placed in the container 5. By adjusting the volume of the capsule 7 and the capacity of the liquid 6, the capsule 7 is suspended in the liquid 6. The vibration excitation module 1 is connected to the drone 4 through bolts, and according to the requirements of the modal test, the corresponding vibration signal is output to make the test piece vibrate. The force feedback module 2 is arranged between the first rigid rod 8 and the drone 4 to measure the inertial force generated by the vibration of the capsule 7. The inertial force compensation module 3 is connected to the drone 4 through the second rigid rod 9, and the force feedback module 2 transmits the measured inertial force to the compensation exciter, and the compensation exciter outputs a compensation force with the opposite direction and equal magnitude to the inertial force. In this way, the drone 4 is always in a free state by utilizing the principle of the interaction between the capsule 7 suspension and the compensation exciter, and the flight state of the drone 4 can be simulated to the greatest extent possible, thereby obtaining accurate modal parameters.

[0062] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A zero-frequency modal test support system, characterized in that: include: A suspension support module, wherein a liquid and a suspension component suspended in the liquid are provided in the suspension support module, and the suspension component is used to be rigidly connected to the test piece; A force feedback module, the force feedback module is connected between the suspension component and the test piece and measures the inertial force generated by the vibration of the suspension component; An inertia force compensation module, the inertia force compensation module is used to be connected to the test piece and provide a compensation force to offset the inertia force; A controller is used to control the inertia force compensation module to provide the compensation force according to the inertia force.

2. The zero-frequency modal test support system according to claim 1, characterized in that: The suspension support module comprises: a container, wherein the liquid is arranged in the container; A first rigid rod, wherein the upper end of the first rigid rod is disposed in the container and connected to the capsule, the lower end of the first rigid rod extends outside the container and is used to be connected to the test piece, and the first rigid rod is movably and hermetically connected to the container; The suspension component is a capsule.

3. The zero-frequency modal test support system according to claim 2, characterized in that: The upper end of the force feedback module is connected to the lower end of the first rigid rod, and the lower end of the force feedback module is used to be connected to the test piece.

4. The zero-frequency modal test support system according to claim 2, characterized in that: The capsule body has a streamlined shape.

5. The zero-frequency modal test support system according to claim 4, characterized in that: The capsule is an elliptical ellipsoid.

6. The zero-frequency modal test support system according to claim 2, characterized in that: The capsule is capable of adjusting volume.

7. The zero-frequency modal test support system according to claim 2, characterized in that: At least one of the bladder and the rigid rod is capable of adjusting weight.

8. The zero-frequency modal test support system according to claim 1, characterized in that: The controller is a PID controller.

9. The zero-frequency modal test support system according to claim 1, characterized in that: The inertia force compensation module is connected to the test piece through a second rigid rod, and the position of the inertia force compensation module corresponds to the position of the suspension support module.

10. A modal test device, characterized in that: include: At least one zero-frequency modal test support system according to any one of claims 1 to 9; A vibration excitation module, wherein the vibration excitation module is used to be connected to the test piece and provide the vibration required for the modal test.

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