Deployable bistable composite rod piezoelectric active vibration suppression method and test system

Abstract

The invention belongs to the technical field of vibration testing of space deployable structures, and particularly relates to a piezoelectric active vibration suppression method and testing system for a deployable bistable composite rod. The method comprises the following steps: fixing a deployable bistable carbon fiber composite material rod and a laser sensor on a test substrate; an MFC actuator is pasted on the expandable bistable carbon fiber composite material rod; the MFC actuator applies an excitation signal to the expandable bistable carbon fiber composite rod and then stops excitation; the laser sensor collects vibration information of the expandable bistable carbon fiber composite rod and sends the vibration information to the controller; the controller receives the vibration information sent by the laser sensor and sends a control instruction to the MFC actuator according to the vibration information, and active vibration suppression of the MFC actuator is achieved. The vibration active control technology is adopted, control is simple, vibration of multiple modes can be autonomously controlled according to sensing signals, the vibration amplitude can be greatly restrained, and adaptability is good.

Description

Technical Field

[0001] The present invention belongs to the technical field of vibration testing of spatially deployable structures, and in particular relates to a piezoelectric active vibration suppression method and a testing system for a deployable bistable composite material rod. Background Art

[0002] Deployable structures have a wide range of applications in the aerospace field, including solar wings, solar sails, space telescope mounts, and retractable winding antennas. Deployable structures made from carbon fiber composites offer advantages such as lightweight, high flexibility, a high density ratio, and the ability to be deployed and retracted multiple times. Their application in spacecraft deployment systems can effectively save storage space and reduce system complexity.

[0003] Space structures are inevitably subject to disturbances such as frequent collisions and impacts introduced by modular assembly, space robot operations, and aerospace attitude adjustments. Furthermore, as structures become increasingly flexible, structural vibration becomes increasingly prominent. This leads to dynamic responses in space structures that generate vibrations in various modes. However, the lack of external damping in the space environment and the minimal internal damping of space structures necessitate vibration suppression. Therefore, there is an urgent need for a lightweight, adaptable active vibration suppression method and system for bistable rod curved surfaces. Summary of the Invention

[0004] In response to the above problems, the purpose of the present invention is to provide a piezoelectric active vibration suppression method and testing system for a deployable bistable composite material rod. Piezoelectric smart material (MFC) is pasted on the bistable rod to achieve active vibration suppression. The vibration signal of the bistable rod is collected by a sensor, and the signal is processed by a host computer and output as a control voltage. After amplification by a high-voltage amplifier, it is output to the piezoelectric sheet interface, thereby actively suppressing the vibration of the bistable rod.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] In one aspect, the present invention provides a method for piezoelectric active vibration suppression of a deployable bistable composite rod, comprising the following steps:

[0007] The deployable bistable carbon fiber composite rod and the laser sensor are fixed on a test substrate;

[0008] A MFC actuator is attached to a deployable bistable carbon fiber composite rod;

[0009] The MFC actuator applies an excitation signal to the deployable bistable carbon fiber composite rod and then stops the excitation;

[0010] The laser sensor collects vibration information of the deployable bistable carbon fiber composite rod and sends the vibration information to the controller;

[0011] The controller receives vibration information sent by the laser sensor and sends control instructions to the MFC actuator according to the vibration information to achieve active vibration suppression of the MFC actuator.

[0012] The laser sensor tests the vibration displacement of the deployable bistable carbon fiber composite material rod and makes a difference between the voltage signal and the initially set balance point to generate a deviation signal, which is input into the controller.

[0013] The controller first outputs a control signal to enable the MFC brake to apply an excitation signal to the deployable bistable carbon fiber composite rod for ten seconds and then stop, and starts an active vibration suppression program at the tenth second.

[0014] The controller adjusts the control parameters through the PID algorithm according to the vibration information collected by the laser sensor to realize the function of controlling the output signal, thereby controlling the MFC actuator to actively suppress the vibration of the deployable bistable carbon fiber composite rod.

[0015] Another aspect of the present invention provides a piezoelectric active vibration suppression test system for a deployable bistable composite rod, comprising a deployable bistable carbon fiber composite rod, an MFC actuator, a support base, a clamp, a test substrate, a laser sensor, a sensor bracket, and a controller, wherein the support base and the sensor bracket are fixed to the test substrate, one end of the deployable bistable carbon fiber composite rod is connected to the support base via the clamp, and the other end of the deployable bistable carbon fiber composite rod is in a cantilever state; the MFC actuator is attached to the deployable bistable carbon fiber composite rod, and the MFC actuator is used to apply an excitation signal to the deployable bistable carbon fiber composite rod;

[0016] A laser sensor is mounted on a sensor bracket and is used to collect vibration information from the deployable bistable carbon fiber composite rod and transmit the information to a controller. The controller receives the vibration information from the laser sensor and, based on the information, sends control instructions to the MFC actuator to achieve active vibration suppression of the MFC actuator.

[0017] The clamp includes a fixing plate and a fixing core, the fixing core is fixed on the support seat, the fixing plate is arranged above the fixing core, and the end of the expandable bistable carbon fiber composite material rod is clamped and fixed between the fixing plate and the fixing core.

[0018] The shapes of the fixing plate and the fixing core are adapted to the shape of the deployable bistable carbon fiber composite material rod.

[0019] The MFC actuator is adhered to the side of the deployable bistable carbon fiber composite material rod close to the clamper by using epoxy resin glue.

[0020] The support base is provided with a plurality of support base mounting holes along the height direction for adjusting the mounting height of the clamp.

[0021] The test substrate is made of aluminum profile, and threaded holes are evenly distributed on the test substrate to adjust the installation positions of the support base and the sensor bracket.

[0022] The advantages and beneficial effects of the present invention are:

[0023] 1. The present invention manufactures a deployable composite rod based on the actual deployment structure of a roll-up flexible satellite solar wing. The constructed assembly clamping structure can well match the constraint relationship in actual application, providing convenience for subsequent analysis of complex deployment model vibration suppression.

[0024] 2. The present invention uses MFC intelligent piezoelectric materials as actuators to actively suppress the vibration of deployable composite rods, and proposes a new method for active vibration suppression of spatial deployable structures.

[0025] 3. The present invention adopts active vibration control technology, which is simple to control. It can autonomously control vibrations of various modes according to sensor signals and can significantly suppress the vibration amplitude, making the present invention have the advantages of simple operation, light weight and good adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic structural diagram of the deployable bistable composite rod piezoelectric active vibration suppression test system of the present invention;

[0027] Figure 2 An axonometric view of a deployable bistable carbon fiber composite rod to which an MFC actuator is attached according to the present invention;

[0028] Figure 3 A top view of a deployable bistable carbon fiber composite rod to which an MFC actuator is attached according to the present invention;

[0029] Figure 4 It is an axonometric view of the fixed core in the present invention;

[0030] Figure 5 It is an axonometric view of the fixing plate of the present invention;

[0031] Figure 6 This is an axonometric view of the support seat in the present invention;

[0032] Figure 7 This is a front view of the support base in the present invention;

[0033] Figure 8 Schematic diagram of the active vibration suppression process of the deployable bistable carbon fiber composite material rod in the present invention;

[0034] Figure 9This is a data curve diagram of the sensor measured under the condition of free vibration after excitation for ten seconds in an embodiment of the present invention;

[0035] Figure 10 This is a curve diagram of data measured by the sensor under the condition of first exciting for ten seconds and then actively suppressing vibration in an embodiment of the present invention;

[0036] Figure 11 for Figure 9 and Figure 10 .

[0037] In the figure: 1. Expandable bistable carbon fiber composite rod; 101. Composite rod mounting hole; 2. MFC actuator; 3. Support seat; 301. Support seat mounting hole; 302. Support seat fixing hole; 4. Fixing plate; 401. Fixing plate mounting hole; 5. Fixing core; 501. Side wall mounting hole; 502. Large fixing hole at the bottom; 503. Small fixing hole at the bottom; 6. Test substrate; 7. Laser sensor; 8. Sensor bracket; 18. Free vibration curve when not connected to control; 19. Vibration curve of the expandable structure after connecting to control. DETAILED DESCRIPTION

[0038] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] See also Figures 1 to 8 As shown, an embodiment of the present invention provides a method for piezoelectric active vibration suppression of a deployable bistable composite rod, comprising the following steps:

[0040] Fix the deployable bistable carbon fiber composite rod 1 and the laser sensor 7 on the test substrate 6;

[0041] A MFC actuator 2 is attached to a deployable bistable carbon fiber composite rod 1;

[0042] The MFC actuator 2 applies an excitation signal to the deployable bistable carbon fiber composite rod 1 and then stops the excitation;

[0043] The laser sensor 7 collects vibration information of the deployable bistable carbon fiber composite rod 1 and sends the vibration information to the controller;

[0044] The controller receives the vibration information sent by the laser sensor 7 and sends a control instruction to the MFC actuator 2 according to the vibration information. The MFC actuator 2 receives the control instruction sent by the controller and excites and actively suppresses the deployable bistable carbon fiber composite rod 1 according to the control instruction.

[0045] See also Figure 8As shown, in the embodiment of the present invention, the laser sensor 7 tests the vibration displacement of the deployable bistable carbon fiber composite rod 1 and generates a voltage signal which is different from the initial set balance point to generate a deviation signal, which is input into the controller.

[0046] Specifically, the controller first outputs a control signal to allow the MFC brake 2 to apply an excitation signal to the deployable bistable carbon fiber composite rod 1 for ten seconds and then stop, and starts the active vibration suppression program at the tenth second.

[0047] In an embodiment of the present invention, the controller adjusts the control parameters through the PID algorithm based on the vibration information collected by the laser sensor 7 to realize the function of controlling the output signal, and then controls the MFC actuator 2 to actively suppress the vibration of the deployable bistable carbon fiber composite rod 1.

[0048] This paper proposes a method for active piezoelectric vibration suppression using deployable bistable composite rods. This method addresses the vibration issues encountered by deployable structures in aerospace applications, such as solar wings and solar sails, by providing a lightweight and adaptable active vibration suppression solution. This solution utilizes a laser sensor to contactlessly detect vibrations of the deployable structure and transmit this information to a controller. The controller, based on the vibration information, sends control commands to an MFC actuator, which then actively suppresses the deployable structure. Experimental results demonstrate that this system can significantly suppress vibrations and offers advantages such as ease of operation, light weight, and high adaptability.

[0049] See also Figures 1 to 8 As shown, another embodiment of the present invention provides a piezoelectric active vibration suppression test system for a deployable bistable composite rod, comprising a deployable bistable carbon fiber composite rod 1, an MFC actuator 2, a support base 3, a clamp, a test substrate 6, a laser sensor 7, a sensor bracket 8, and a controller. The support base 3 and the sensor bracket 8 are fixed to the test substrate 6. One end of the deployable bistable carbon fiber composite rod 1 is connected to the support base 3 via the clamp, and the other end of the deployable bistable carbon fiber composite rod 1 is in a cantilevered state. The MFC actuator 2 is attached to the deployable bistable carbon fiber composite rod 1 and is used to apply an excitation signal to the deployable bistable carbon fiber composite rod 1. The laser sensor 7 is disposed on the sensor bracket 8 and is located on one side of the deployable bistable carbon fiber composite rod 1. The laser sensor 7 is used to contactlessly detect vibration information of the deployable bistable carbon fiber composite rod 1 and transmit the vibration information to the controller. The controller receives the vibration information transmitted by the laser sensor 7 and, based on the vibration information, sends control instructions to the MFC actuator 2 to implement active vibration suppression of the MFC actuator 2.

[0050] See also Figure 1As shown, in an embodiment of the present invention, the clamp includes a fixing plate 4 and a fixing core 5, the fixing core 5 is fixed on the support seat 3, the fixing plate 4 is arranged above the fixing core 5, and the end of the expandable bistable carbon fiber composite material rod 1 is clamped and fixed between the fixing plate 4 and the fixing core 5.

[0051] Furthermore, the shapes of the fixing piece 4 and the fixing core 5 are adapted to the shape of the deployable bistable carbon fiber composite material rod 1 .

[0052] See also Figure 2 and Figure 3 As shown, in this embodiment of the present invention, the MFC actuator 2 is attached to the side of the deployable bistable carbon fiber composite rod 1 near the clamp using epoxy glue. The deployable bistable carbon fiber composite rod 1 is also provided with multiple composite rod mounting holes 101 at the end near the clamp, which are used to connect to the clamp.

[0053] Specifically, the MFC actuator 2 is a piezoelectric fiber diaphragm that functions as an actuator based on the direct piezoelectric effect.

[0054] See also Figure 4 As shown, in the embodiment of the present invention, the stationary core 5 is a cylindrical structure with a large bottom fixing hole 502 at the center of its bottom and two small bottom fixing holes 503 symmetrically arranged on either side of the large bottom fixing hole 502. The large bottom fixing hole 502 and the two small bottom fixing holes 503 are connected to the support base mounting hole 301 on the support base 3 via bolts. Multiple side wall mounting holes 501 are evenly distributed along the circumference of the side wall of the stationary core 5. The side wall mounting holes 501 are used to connect to the deployable bistable carbon fiber composite rod 1 and the fixing plate 4. The provision of multiple side wall mounting holes 501 facilitates adjustment of the installation position of the deployable bistable carbon fiber composite rod 1.

[0055] See also Figure 5 As shown, in the embodiment of the present invention, the fixing plate 4 is provided with fixing plate mounting holes 401 corresponding one-to-one to the side wall mounting holes 501 on the fixing core 5 .

[0056] See also Figure 6 and Figure 7 As shown, in the embodiment of the present invention, the support base 3 is provided with multiple groups of support base mounting holes 301 along the height direction for adjusting the mounting height of the clamp. The bottom of the support base 3 is provided with a support base fixing hole 302 for connecting with the test substrate 6.

[0057] Specifically, the test substrate 6 is the foundation of the entire system. For ease of installation and cost reduction, a square aluminum alloy plate is used. As the substrate's primary function is to withstand the forces generated by the vibration of the deployable bistable carbon fiber composite rod 1, stability is paramount. Threaded holes are evenly distributed throughout the test substrate 6 to adjust the mounting position of the support base 3 and sensor bracket 8, thereby adjusting the position of the deployable bistable carbon fiber composite rod 1 and laser sensor 7. As the intermediate structure connecting the deployable bistable carbon fiber composite rod 1 and the test substrate 6, the support base 3 requires significant rigidity. To facilitate processing and meet rigidity requirements, a 45 steel plate is used.

[0058] In the embodiment of the present invention, since the test system requires external drive equipment, data acquisition equipment and signal amplification equipment when working, all the equipment are placed in the vacant space on the right end of the test substrate 6. The structural components of the present invention are connected by screws, and the support seat 3 requires a welding process. In order to ensure the strength of the structure, an arc welding process is used. The overall equipment installation error requirement is not high, but the equipment needs to be leveled and straightened. This test system is mainly for studying the active vibration suppression of the deployable mechanism. It is necessary to analyze the solar energy vibration mechanism, establish the dynamic equation of the deployable structure on a theoretical basis, and study and design the control algorithm for the vibration suppression of the sailboard. The algorithm currently used is the PID algorithm. The MFC actuator 2 uses a piezoelectric fiber sheet. According to the positive piezoelectric effect, it can also be used in conjunction with the deployable structure to establish a dynamic equation for the model simulation and simulation of the system.

[0059] The present invention provides a deployable bistable composite rod piezoelectric active vibration suppression test system, the working principle of which is:

[0060] According to the forward and inverse piezoelectric effects of piezoelectric ceramics, when a piezoelectric ceramic is deformed, a charge shift occurs in the piezoelectric ceramic, generating a potential difference, that is, a voltage. Depending on the size of the deformation (without destroying the internal structure), the larger the deformation, the greater the voltage difference. When a voltage is applied to both ends of the piezoelectric ceramic electrode, the piezoelectric ceramic will deform, and the greater the voltage, the greater the deformation.

[0061] Based on the above principles, a joint dynamic analysis of the deployable bistable carbon fiber composite rod 1 and the piezoelectric fiber sheet was performed to create a dynamic equation. The MFC piezoelectric fiber sheet was attached to the deployable bistable carbon fiber composite rod 1. A control signal was first output to cause the MFC actuator 2 to apply an excitation signal to the deployable bistable carbon fiber composite rod 1 for ten seconds before stopping. At the tenth second, the active vibration suppression program was initiated. The vibration deformation of the deployable bistable carbon fiber composite rod 1 was captured by a laser sensor 7 and then subjected to a series of signal processing steps, including amplification and filtering, before being input to the controller. A voltage was then output according to a specific control algorithm and applied to the MFC actuator 2. In this way, the deformation of the MFC actuator 2 affects the vibration of the deployable bistable carbon fiber composite rod 1. Through this complete process, the purpose of active vibration suppression was achieved.

[0062] Figure 8 This is the flow chart of active vibration suppression control for deployable structures; see Figure 8 As shown, the laser sensor 7 measures the vibration displacement of the deployable structure, generates a voltage signal, and makes a difference between the voltage signal and the initial set equilibrium point (generally 0) to generate a deviation signal. The deviation signal is input into the controller, and the PID control algorithm adjusts the PID parameters kp, TI, and TD to realize the function of controlling the output signal. The control signal is loaded into the MFC actuator 2 via the amplifier. The MFC actuator 2 generates deformation due to the inverse piezoelectric effect, thereby achieving the effect of suppressing the vibration of the deployable structure.

[0063] Figure 9 The present invention uses an MFC actuator to excite for ten seconds and then stop the excitation output, which can develop a vibration curve of the free vibration of the bistable carbon fiber composite rod 1; Figure 10 The present invention uses an MFC actuator to excite for ten seconds and then stop the excitation. The active vibration suppression program is started at the tenth second, and the active vibration suppression vibration curve of the bistable carbon fiber composite rod 1 can be developed; Figure 11 1 is a comparison diagram of the vibration curves of the deployable structure before and after the control is connected according to the present invention; among them, the free vibration curve 18 before the control is connected is compared with the vibration curve 19 of the deployable structure after the control is connected. It can be seen that the amplitude and vibration time of the deployable structure are significantly reduced after the control is connected.

[0064] In the embodiment of the present invention, a data acquisition card from NI is used as the signal acquisition device, and Labview software is used as the data processing and system control software, which ensures the stability of the system and lays the foundation for the future development of space control equipment.

[0065] The present invention has convenient measurement, clear structure and simple operation. It can simulate actual working conditions to measure the parameters of the deployable structure under forced vibration and free vibration for analysis, and perform active vibration suppression control through actuators. It plays an important role in the future design of spatial flexible deployable mechanisms, the design of active vibration suppression equipment and controllers based on test systems, and the research of control algorithms.

[0066] The above description is only an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modification, equivalent replacement, improvement, expansion, etc. made within the spirit and principle of the present invention are included in the scope of protection of the present invention.

Claims

1. A method for piezoelectric active vibration suppression of a deployable bistable composite rod, characterized in that: The following steps are involved: Fixing the deployable bistable carbon fiber composite rod (1) and the laser sensor (7) on a test substrate (6); A MFC actuator (2) is attached to a deployable bistable carbon fiber composite rod (1); The MFC actuator (2) applies an excitation signal to the deployable bistable carbon fiber composite rod (1) and then stops the excitation; The laser sensor (7) collects vibration information of the deployable bistable carbon fiber composite material rod (1) and sends the vibration information to the controller; The controller receives vibration information sent by the laser sensor (7), and sends a control instruction to the MFC actuator (2) according to the vibration information, thereby realizing active vibration suppression of the MFC actuator (2).

2. The method for piezoelectric active vibration suppression of a deployable bistable composite rod according to claim 1, characterized in that: The laser sensor (7) measures the vibration displacement of the deployable bistable carbon fiber composite material rod (1), and generates a deviation signal by subtracting the voltage signal from the initially set equilibrium point. The deviation signal is input into the controller.

3. The method for piezoelectric active vibration suppression of a deployable bistable composite rod according to claim 1, characterized in that: The controller first outputs a control signal to allow the MFC brake (2) to apply an excitation signal to the deployable bistable carbon fiber composite rod (1) for ten seconds and then stops, and starts an active vibration suppression program at the tenth second.

4. The method for piezoelectric active vibration suppression of a deployable bistable composite rod according to claim 1, characterized in that: The controller adjusts control parameters through a PID algorithm based on vibration information collected by the laser sensor (7) to achieve a function of controlling the output signal, thereby controlling the MFC actuator (2) to actively suppress vibration of the deployable bistable carbon fiber composite rod (1).

5. A deployable bistable composite rod piezoelectric active vibration suppression test system, characterized in that: The invention comprises a deployable bistable carbon fiber composite material rod (1), an MFC actuator (2), a support seat (3), a clamp, a test substrate (6), a laser sensor (7), a sensor bracket (8), and a controller, wherein the support seat (3) and the sensor bracket (8) are fixed on the test substrate (6); one end of the deployable bistable carbon fiber composite material rod (1) is connected to the support seat (3) via the clamp, and the other end of the deployable bistable carbon fiber composite material rod (1) is in a cantilever state; the MFC actuator (2) is attached to the deployable bistable carbon fiber composite material rod (1), and the MFC actuator (2) is used to apply an excitation signal to the deployable bistable carbon fiber composite material rod (1); A laser sensor (7) is arranged on a sensor bracket (8), and the laser sensor (7) is used to collect vibration information of a deployable bistable carbon fiber composite material rod (1), and transmit the vibration information to a controller; the controller receives the vibration information transmitted by the laser sensor (7), and transmits a control instruction to an MFC actuator (2) based on the vibration information, thereby realizing active vibration suppression of the MFC actuator (2).

6. The deployable bistable composite rod piezoelectric active vibration suppression test system according to claim 5, characterized in that: The clamp comprises a fixing plate (4) and a fixing core (5), the fixing core (5) being fixed on the support seat (3), the fixing plate (4) being arranged above the fixing core (5), and the end of the expandable bistable carbon fiber composite material rod (1) being clamped and fixed between the fixing plate (4) and the fixing core (5).

7. The deployable bistable composite rod piezoelectric active vibration suppression test system according to claim 6, characterized in that: The shapes of the fixing plate (4) and the fixing core (5) are adapted to the shape of the deployable bistable carbon fiber composite material rod (1).

8. The deployable bistable composite rod piezoelectric active vibration suppression test system according to claim 5, characterized in that: The MFC actuator (2) is adhered to the side of the deployable bistable carbon fiber composite material rod (1) close to the clamper using epoxy resin glue.

9. The deployable bistable composite rod piezoelectric active vibration suppression test system according to claim 5, characterized in that: The support seat (3) is provided with a plurality of groups of support seat mounting holes (301) along the height direction for adjusting the mounting height of the clamp.

10. The deployable bistable composite rod piezoelectric active vibration suppression test system according to claim 5, characterized in that: The test substrate (6) is made of aluminum profile, and threaded holes are evenly distributed on the test substrate (6) for adjusting the installation positions of the support seat (3) and the sensor bracket (8).

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