A 0-frequency modal test support system and test device

Abstract

The application provides a 0-frequency mode test support system and test device, and belongs to the field of unmanned aerial vehicle test. The support system comprises a suspension support module, a force feedback module, an inertial force compensation module and a controller. The suspension support module is internally provided with liquid and a suspension component suspended in the liquid. The suspension component is used for rigid connection with a test piece. The force feedback module is used for connection with the test piece and measurement of inertial force generated due to vibration of the suspension component. The inertial force compensation module is used for connection with the test piece and provision of compensation force for offsetting the inertial force. The controller is used for controlling the inertial force compensation module to provide the compensation force according to the inertial force. The suspension support module can balance the gravity of the test piece, cooperate with the compensation force provided by the compensation exciter, enable the test piece to be always in a follow-up balance state and have a very low or even 0-frequency vibration state, can completely simulate the real running state of the test piece suspended in the air or liquid, and thus accurate modal parameters can be obtained.

Description

Technical Field

[0001] The present invention belongs to the field of unmanned aerial vehicle (UAV) 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 UAV modal characteristics. Summary of the Invention

[0003] The purpose of the present invention is to provide a zero-frequency modal test support system and 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 objectives, in a first aspect, the present invention provides a zero-frequency modal test support system, comprising:

[0005] A suspension support module, 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;

[0006] a force feedback module connected between the suspension component and the test piece and measuring the inertial force generated by the vibration of the suspension component;

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

[0008] A controller is configured to control the inertial force compensation module to provide the compensation force according to the inertial force.

[0009] Optionally, the suspension support module includes:

[0010] a container, wherein the liquid is provided 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 connect 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 volume adjustable.

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

[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 the position of the inertial force compensation module corresponds to the 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 is used to connect with 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; and the controller is used to control the inertia force compensation module to provide a compensation force based on the inertia force. The suspension support module can balance the gravity of the test piece, and in conjunction with the compensation force provided by the compensating exciter, it can keep the test piece in a dynamic equilibrium state and have an extremely low or even zero-frequency vibration state. It can fully simulate the actual operating state of the test piece suspended in the air or in the liquid, thereby obtaining 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 with reference to the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0026] Figure 1 FIG2 shows a schematic structural diagram of a zero-frequency modal test support system in Embodiment 1 of the present invention.

[0027] Figure 2 FIG2 shows a schematic structural diagram of a modal test device in a second embodiment of the present invention.

[0028] Figure numerals in Example 2:

[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. Instead, 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] Example 1:

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

[0033] A 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 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 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 utilizes the suspension characteristics to balance the gravity of the test piece 11, and the inertia force compensation module 3 can provide a controllable force to offset the inertia force generated by the vibration of the suspension component. The suspension support module 10 and the inertia force compensation module 3 cooperate to make the test piece 11 always in a dynamic equilibrium state and have an extremely low or even zero frequency vibration state. It 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 easy use and maintenance. The force feedback module 2, the inertia 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 the first rigid rod 8 is disposed in the container 5 and connected to the capsule 7, the lower end of the first rigid rod 8 extends outside the container 5 and is used to connect 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 low resistance characteristics, which reduces the influence of the shape of the capsule 7 on vibration.

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

[0048] Optionally, the volume of the balloon 7 can be adjusted.

[0049] Specifically, the volume of the bladder 7 can be adjusted by inflating or deflating, thereby adjusting the buoyancy, so that 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 an existing technology, 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 through 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] Example 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 according to 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 modules 1 is set according to the structural shape of the test piece and the test requirements.

[0061] In this embodiment, the test object is a drone 4, two zero-frequency modal test support systems are provided, and two vibration excitation modules 1 are provided. After being connected to the drone 4 via a first rigid rod 8, the capsule 7 is placed in a liquid 6, which is placed in a 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 via bolts and outputs a corresponding vibration signal according to the modal test requirements, causing the test object to vibrate. The force feedback module 2 is located between the first rigid rod 8 and the drone 4 and measures the inertial force generated by the vibration of the capsule 7. The inertial force compensation module 3 is connected to the drone 4 via a second rigid rod 9. The force feedback module 2 transmits the measured inertial force to the compensating vibrator, which outputs a compensation force of equal magnitude and opposite direction to the inertial force. In this way, by utilizing the principle of the interaction between the suspension of the capsule 7 and the compensating vibrator, the drone 4 is always in a free state, and the flight state of the drone 4 can be simulated to the greatest extent possible, thereby obtaining accurate modal parameters.

[0062] Having described various embodiments of the application, it is to be understood that the above description is meant to be illustrative only, and that many modifications and variations of the embodiments are possible without departing from the scope and spirit of the described embodiments. Many modifications and variations of the described embodiments are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims and their equivalents, the described embodiments can be practiced otherwise than as specifically described.

Claims

1. A zero-frequency modal test support system, characterized in that: include: A suspension support module, 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; a force feedback module connected between the suspension component and the test piece and measuring the inertial force generated by the vibration of the suspension component; An inertia force compensation module, the inertia force compensation module being used to be connected to the test piece and to provide a compensation force to offset the inertia force; a controller, configured to control the inertial force compensation module to provide the compensation force according to the inertial force; The suspension component is a capsule; The suspension support module includes: a container, wherein the liquid is provided 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 connect to the test piece, and the first rigid rod is movably and hermetically connected to the container; 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; 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.

2. The zero-frequency modal test support system according to claim 1, characterized in that: The capsule has a streamlined shape.

3. The zero-frequency modal test support system according to claim 2, characterized in that: The capsule is an ellipsoid.

4. The zero-frequency modal test support system according to claim 1, characterized in that: The volume of the balloon can be adjusted.

5. The zero-frequency modal test support system according to claim 1, characterized in that: At least one of the bladder and the rigid rod is capable of adjusting weight.

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

7. 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 6; A vibration excitation module is used to connect with the test piece and provide the vibration required for the modal test.

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