CN100554908C - Simulation intelligent flexible space sailboard structural vibration active control test platform and method - Google Patents

Abstract

The invention relates to an active control test platform and method for simulating intelligent flexible space sailboard structure vibration. The test platform of the present invention includes a set of mechanical clamping devices, a flexible vibration board, a signal generator, a high-performance DSP board, an oscilloscope, a computer, a display, an exciter, multiple electric amplifier, multiple low-pass filters, multiple piezo power amplifiers, piezo sensing network, and piezo drive network. The present invention uses the piezoelectric ceramic element as the body material of the sensor network and the driver network, uses the DSP measurement and control unit as the core of signal detection, algorithm operation and output control signal, and uses the PC as the test control platform and observation interface to provide a The test platform and test method for the active control of vibration of space flexible structures based on simulated piezoelectric intelligence.

Description

Simulation intelligent flexible space sailboard structural vibration active control test platform and method

technical field

The invention relates to an active control test platform and method for simulating intelligent flexible space sailboard structure vibration, in particular to a piezoelectric intelligent material flexible board structure vibration active control test platform and method based on DSP measurement and control core.

Background technique

The solar panels of aerospace vehicles usually exist in the space environment in the form of large cantilever beam structures, and have the characteristics of low stiffness, small damping, low natural frequency and dense low-order modes. Due to the harsh space environment, the influence of cosmic wind, particle flow, and the maneuvering of the spacecraft itself, it is very easy to cause continuous vibration of the solar panel structure of the spacecraft. If effective anti-vibration measures are not taken, its large-scale vibration response will last for a long time, which will not only affect the working performance of the flexible structure itself, but also affect the attitude stability of the spacecraft through coupling with the main body of the spacecraft. And orientation accuracy problems; long-term and strong vibration will also cause structural fatigue damage, leading to system performance degradation or even failure, directly threatening the safety of aerospace structures, which has been exemplified in actual spacecraft operations. Therefore, the research on vibration control of large flexible aerospace structures has always been an important field and a difficult topic in the development of aerospace technology. In the report "Space Technology in the New Century", the National Research Council of the United States will Stabilizing various flexible structures, antennas and telescopes" is listed as one of the six key technologies affecting space exploration.

In view of the performance requirements of aerospace systems and the vibration characteristics of space structures, the concept of intelligent material structure is currently used to realize active vibration control. Due to the high technical difficulty and important application value, it has received extensive attention and hot research from researchers in related fields at home and abroad. However, although the research on active vibration-reducing intelligent structures is deepening, it is still far from mature in terms of theoretical research and engineering practice, and there are still many problems to be explored and resolved. For large aerospace structures, it is impossible to establish an accurate mathematical model due to the complexity of the structure and the existence of large deformation nonlinear effects. Robustness requirements are put forward by the controller, and the problems of adaptive adjustment and online learning must also be properly solved. In this case, in recent years, the controller design of such systems has been explored using modal control, pole configuration, optimal control method, robust control, adaptive control, intelligent control and neural network control, and has been studied in theory and Some meaningful results have been obtained in the experiment. But generally speaking, these methods have only achieved preliminary realization, their development is immature, and their applications have their own limitations, so further exploration and research are still needed.

Contents of the invention

The purpose of the present invention is to provide a test platform and method for simulating the active control of vibration of intelligent flexible space sailboard structure, which can provide scientific theoretical analysis and experimental verification means for the active control of piezoelectric flexible board intelligent structure vibration, and provide a basis for exploring theoretical methods Provide technical support for further practical engineering applications.

To achieve the above object, design of the present invention is:

Combining the research status and development trend of active vibration-reducing intelligent structures, and analyzing the composition of flexible intelligent structures, the current research and application of piezoelectric materials PZT/PVDF can be considered as the most representative achievements. When piezoelectric materials are used as sensors, their main characteristics are low sensitivity to temperature changes, high strain sensitivity and low noise; when used as drivers, they have the characteristics of low power consumption, electrical operation, frequency bandwidth and force generated internally by themselves. Therefore, it is very suitable for the vibration monitoring and control of aerospace structures. Aiming at the continuous in-depth research on the active control of space flexible sailboard structure vibration based on the connotation of piezoelectric intelligent structure, a reasonable and effective test platform is built on the basis of the design of the test structure model and the development of the measurement and control system.

The platform uses piezoelectric ceramic elements as the sensor network and driver network to be implanted on the surface of the sailboard structure, uses the DSP measurement and control unit as the core of collecting detection signals, implementing control algorithms and outputting control signals, and uses the PC and the developed software environment as the core. Observation platform for test operators.

According to above-mentioned inventive design, the present invention adopts following technical scheme:

An active control test platform for simulating intelligent flexible space sailboard structure vibration, including a set of mechanical clamping devices, an intelligent piezoelectric model structure flexible board, a signal generator, a DSP measurement and control board, an oscilloscope, a A computer, along with an exciter, a set of charge amplifiers, a set of low-pass filters, a set of piezoelectric power amplifiers, a piezoelectric sensing network, and a piezoelectric drive network. It is characterized in that both the piezoelectric sensing network and the piezoelectric driving network are distributed on the surface of the flexible plate of the intelligent piezoelectric model structure in the form of a network patch, and the flexible plate is clamped on the mechanical clamping device in the attitude of a cantilever beam, and the signal generator The excitation signal is output to the exciter, and the excitation of the flexible plate structure of the intelligent piezoelectric model by the exciter causes the flexible plate to generate a corresponding vibration response. The piezoelectric sensor network detects the structural vibration response signal, and passes through the charge amplifier and low-pass The conditioning of the filter is output to the DSP measurement and control board connected to the computer through the PCI interface, and then the control signal is generated according to the developed DSP control algorithm and the control strategy transmitted by the host computer, and the control signal is amplified by the power amplifier and output Implanted into the piezoelectric drive network of the flexible plate of the intelligent piezoelectric model structure, thereby generating a control effect on the controlled structure, realizing real-time adaptive offsetting of the vibration response of the flexible plate structure of the intelligent piezoelectric model, so as to actively eliminate or reduce the structural vibration response the goal of. While performing measurement and control, the test platform can also transmit sensing signals, control signals, control parameters and overall performance parameters to the host computer to realize real-time display and storage functions.

The above-mentioned mechanical clamping device is a steel frame structure, which is characterized by stability, safety, and good adjustability. It is integrated with the flexible plate structure of the intelligent piezoelectric model, and the vibration response of the flexible plate body can be aimed at the steel frame structure, excitation The vibration coupling of the vibrator, support platform and other equipment can be reduced to a negligible level; in addition, the position of the vibrator fixed on the steel frame structure can be adjusted, and multiple vibrators can be used to apply vibration to the flex plate structure at the same time Excitation, so that the multi-mode vibration characteristics of the structure can be obtained and the multi-mode vibration active control test can be carried out.

The above-mentioned simulated space sailboard structure is a flexible board made of epoxy resin, which is characterized in that a plurality of piezoelectric sensors are pasted on the surface of the flexible board structure to form a piezoelectric sensor network, and a plurality of piezoelectric drivers are pasted to form a piezoelectric drive network. , the layout of the piezoelectric sensing network and the piezoelectric driving network is carried out on the basis of the analysis of the modal characteristics of the flex plate structure. The influence of the original mode of the flexible plate is applicable to the test requirements of various control strategies.

An intelligent flexible space sailboard structural vibration active control test method, using the above-mentioned equipment and test platform for testing, is characterized in that the operating steps of the test are as follows:

(1) Use the modal analysis method to analyze the vibration characteristics of the flexible plate structure, obtain the natural vibration frequencies of each order in the lower frequency range of the structure, and use the exciter frequency sweep method to revise the natural vibration frequencies of each order of the structure;

(2) Write the program according to the control algorithm and download it to the DSP measurement and control board, and set the parameters of the upper computer software platform, and prepare to start the control after the compilation and debugging are successful;

(3) Start the excitation source signal generator with reference to the structural natural frequency obtained in step (1), and set the frequency and amplitude of the excitation signal;

(4) Adjust the position of the exciter, start the exciter, and excite the flexible plate of the intelligent piezoelectric model structure;

(5) Turn on the charge amplifier, low-pass filter, and oscilloscope to obtain and adjust the structural vibration response signal;

(6) Turn on the piezoelectric power amplifier connected to the piezoelectric drive network;

(7) Set the upper computer operation platform control command according to the set control algorithm, and start the control;

(8) Observe the structural vibration control effect from the oscilloscope and the host computer interface.

The following two points should be noted in the above step (4):

① The action position of the drive rod of the exciter is close to the fixed end of the cantilever flexible plate and on the center line of the flexible plate;

② When starting the vibrator, the output amplitude gradually increases slowly from a small value, and adjusting the amplitude too quickly may cause damage to the flexible board test structure and the piezoelectric sensing and driving network.

Compared with the prior art, the present invention has the following prominent substantive features and significant advantages:

(1) The piezoelectric sensor network and the piezoelectric drive network are optimally arranged according to the goal of the best control effect, which is convenient for reselecting the matching sensor network and drive network according to the need to change the algorithm, and convenient for the experiment of optimal configuration.

(2) The X-Y-Z direction of the exciter is adjustable, which is convenient for simulating the real situation where the actual solar panel is subjected to vibration excitation.

(3) Considering the coupling factors of the system, a stable fastening method is used to combine the system into a whole that can be easily disassembled. Even if the flex plate structure generates relatively severe vibration and is coupled with the overall structure of the system, it can be limited to a tolerable range Inside.

(4) The high-speed measurement and control system based on the DSP measurement and control core meets the online real-time identification requirements of the multi-input/multi-output control mode and the controlled structure system model, and can solve the problem of relatively large amount of calculation and information while ensuring the ability of control tracking. Big question.

(5) The upper computer measurement and control software environment developed for the hardware system of the test platform already has many functions such as hardware drive, DMA communication, waveform display, and data storage; The control scheme can be designed and completed.

(6) For the measurement and control system based on the DSP measurement and control core, although corresponding measurement and control programs need to be developed based on different control algorithms, the basic procedures to ensure the integrity of the system work, such as measurement and control board driver, AD conversion, DA conversion, DMA transmission, and The signal filtering and data analysis functions have realized program modularization, which ensures the reliability and portability of the test platform software environment.

Description of drawings

Fig. 1 is a schematic structural diagram of a test device of a preferred embodiment of the present invention.

Fig. 2 is a schematic diagram of the distribution of the piezoelectric sensing network and the piezoelectric driving network in the preferred example shown in Fig. 1 .

Fig. 3 is a schematic diagram of the steel frame structure experiment platform in the preferred example shown in Fig. 1 .

Fig. 4 is that Fig. 1 shows the overall physical photogram of preferred example test device

Fig. 5 is a flow chart of the upper computer program in the preferred example shown in Fig. 1 .

Fig. 6 is a flow chart of the lower computer program in the preferred example shown in Fig. 1 .

Fig. 7 is a time course diagram of the vibration control performance of the system in the preferred example shown in Fig. 1 .

Detailed ways

A preferred implementation example of the present invention is described as follows in conjunction with accompanying drawing:

Refer to Figure 1, the simulated intelligent flexible space sailboard structural vibration active control test platform, including an epoxy resin flexible board ①, a piezoelectric drive network ②, a piezoelectric sensor network ③, a vibrator ④ (Model: JZK-10 Manufacturing unit: Jiangsu Lianeng Electronics Co., Ltd.), a set of mechanical clamping device ⑤, piezoelectric drive power amplifier ⑥ (Model: APEX-PA95 Manufacturing unit: Department of Automation, Shanghai University), charge amplifier ⑦ ( Model: YE5852A Manufacturer: Jiangsu Lianeng Electronics Co., Ltd.), low-pass filter ⑧ (Model: YE3760A Manufacturer: Jiangsu Lianeng Electronics Co., Ltd.), oscilloscope ⑨, a high-performance DSP board ⑩ (Model: SEED-VC33ps Production unit: Hezhongda Electronics Co., Ltd.), a computer (11), and a signal generator (12) (model: Angilent-A808 Production unit: Agilent Instrument Co., Ltd.). See Figure 4 for the overall photo of the device.

The active control test method for the simulated intelligent flexible space sailboard structure vibration in this example uses the above-mentioned test platform for the test. The operation steps of the test are as follows:

(1) An epoxy resin plate with a size of 1500mm×400mm×1.5mm (length, width and height) is selected as the simulated flexible space sailboard model structure ①, and two bottom and height panels are cut off at the root of the fixed section. The dimensions are about 60mm*160mm triangles, and then the root of the structure is fixed on the angle iron bracket of the test bench.

(2) Fix the exciter ④ on the mechanical clamping device ⑤ to ensure that the vibration position of the free end of the transmission rod is 15cm-30cm away from the root of the flexible board ① and the center line of the flexible board ①, and then fasten the free end with screws to Adagio ①.

(3) The finite element analysis software ANSYS is used to model and analyze the flexible plate ①, and the structural vibration modal characteristics of the lower frequency range of the flexible plate ①, such as the natural frequency of each order, the mode shape of each order, and the maximum strain stress area, etc. , and use the signal generator ⑨ frequency sweep method to check and adjust the above characteristic data.

(4) According to the requirements of detecting/suppressing the maximum structural strain, AB glue is used to paste the piezoelectric sensing network ③ and the piezoelectric driving network ② on the double-sided surface of the flexible board structure ①.

(5) Use the frequency sweep method of the signal generator ⑨ again to check and adjust the vibration characteristic data of each order of the flexible board ①.

(6) According to the structural vibration response characteristic data obtained in the above step (5), according to the requirements of detecting/suppressing the maximum strain of certain lower-order modes, select a part of the sensing network ③ and the driving network ② to form an optimized sensing network Network ③ and Drive Network ②.

(7) On the basis of the original upper computer/lower computer program, the adaptive filter least mean square control algorithm is selected, and the parameters of the adopted control algorithm are set by the DSP measurement and control board ⑩ and the computer (11).

(8) Start the exciter ④, turn on the charge amplifier ⑦, low-pass filter ⑧, oscilloscope ⑨, and power amplifier ⑥, and the structural model is excited and in a state to be controlled.

(9) Implementation of the computer based on the adaptive filter least mean square control algorithm (11) The operating platform issues control commands. (10) Observe the structural vibration response control effect from the oscilloscope ⑨ and the computer (11) interface, and save the test data based on the software environment platform.

(11) Repeat steps (6), (7), (8), (9), and (10) to repeatedly adjust the control algorithm to obtain a good control effect.

In step (1), the simulated flexible space sailboard model structure ① of this preferred example uses epoxy resin board, as shown in ① in Figure 2, this polymer has better strength, and can maintain a better surface when static. After the piezoelectric material is pasted, the long-term static suspension is not easy to deform, and after the vibration excitation is applied, it can produce a better vibration shape, which is close to the vibration characteristics of the actual solar panel in the air and sky environment.

The piezoelectric sensor network ③ and the piezoelectric driver network ② in this preferred example are wrapped and pasted with AB glue, so that the piezoelectric material not only has good sensing/driving ability, but also avoids the danger of touching high-voltage control signals, as shown in the figure Shown in ② and ③ in 2.

The test bench mechanical clamping device ⑤ in this preferred example has degrees of freedom in three directions of X-Y-Z, variable displacement in X direction ±2cm, variable displacement in Y direction ±10cm, variable displacement in Z direction ±3cm, and the size of the bottom of the device is 60cm*60cm*1.8cm steel structure plate, all parts are connected by fastening screws. As shown in Figure 3 a, b.

Step (7) in this preferred example, the flow chart of the DSP measurement and control board ⑩ program is as shown in Figure 5, wherein the board driver, AD/DA conversion, DMA transmission, signal filtering and data analysis programs are all based on C and ASM language Modular programming, standard module interface, easy to call, strong reliability and portability. The control strategy adopts the adaptive filter least mean square control algorithm, which is divided into two control methods according to the different controller structures, that is, the least mean square algorithm based on the finite impulse response filter controller, and the filter control based on the infinite impulse response The least mean square algorithm of the device is written into the DSP measurement and control board ⑩ in the form of a module function; the program flow chart of the computer (11) is shown in a, b, c, and d in Figure 6, which provides user observation and setting commands , data storage, data analysis and comparison and other functions. In this way, the two control algorithms can run smoothly on the active vibration control test platform, and obtain the observation and comparison of control performance indicators such as control speed, attenuation amplitude, followability, reproducibility, and applicable conditions; the overall vibration control attenuation of the system See Figure 7 for the process.

Among Fig. 6, a is the general flowchart of the computer (11) system.

B among Fig. 6 is the hardware operating thread flowchart in the computer (11).

C among Fig. 6 is the flowchart of computer (11) closing control function.

D among Fig. 6 is the flowchart of computer (11) quitting program.

The data format preserved in step (10) in this preferred example is a .txt file format, which is a general format that can be loaded into a variety of analysis software for data analysis, providing convenience and functionality for further data analysis quickness. In this preferred example, Matlab analysis software can be used to analyze the saved experimental data offline, which shows ideal data characteristics and control functions.

Claims (5)

1. simulated intelligence flexible space sail board structural vibration main control test platform, comprise an intelligent piezo model structure adagio (1), Piezoelectric Driving network (2), piezoelectric sensing network (3), a vibrator (4), one cover mechanical clamping device (5), one group of Piezoelectric Driving power amplifier (6), one group of charge amplifier (7), one group of low-pass filter (8), an oscillograph (9), a DSP observing and controlling integrated circuit board (10), a computing machine (11), a signal generator (12), it is characterized in that: described mechanical clamping device (5) is firm steelframe clamp structure, vibrator (4) is connected to intelligent piezo model structure adagio (1), described piezoelectric sensing network (3) and Piezoelectric Driving network (2) all are distributed on the both side surface of intelligent piezo model structure adagio (1) in network situation paster mode, described intelligent piezo model structure adagio (1) is clamped on the mechanical clamping device (5) with the semi-girder attitude, the needed pumping signal of described signal generator (12) output test is to vibrator (4), excitation intelligent piezo model structure adagio (1) produces corresponding vibratory response, described piezoelectric sensing network (3) detects intelligent piezo model structure adagio vibration response signal, conditioning through charge amplifier (7) and low-pass filter (8), be input to pci interface and connect in the DSP observing and controlling integrated circuit board (10) of computing machine (11), produce control signal according to being set in the control strategy order that control algolithm in the DSP observing and controlling integrated circuit board (10) and host computer send, output to Piezoelectric Driving network (2) via Piezoelectric Driving power amplifier (6) drive control signal, produce control action and put on controlled intelligent piezo model structure adagio (1), simultaneously with transducing signal, control signal, controlled variable and integral performance parameter are delivered in the computing machine (11), show in real time, analyze and storage.

2. simulated intelligence flexible space sail board structural vibration main control test platform according to claim 1, it is characterized in that described mechanical clamping device (5) is combined into an integral body for steel frame construction and vibrator (4), thereby obtain vibrator (4) is adjusted the location along three directions of X-Y-Z degree of freedom, make that the drive link active position of vibrator (4) is convenient adjustable, and, adapt to the needs of multi-modal active control in structural vibration test by increase and decrease vibrator (4) number.

3. simulated intelligence flexible space sail board structural vibration main control test platform according to claim 1, the layout that it is characterized in that described piezoelectric sensing driving network (2) and piezoelectric sensing network (3) is based on the basis of intelligent piezo model structure adagio (1) model analysis, two-sided going up pasted piezoelectric sensing network (3) and Piezoelectric Driving network (2) on intelligent piezo model structure adagio (1) surface, reach the obvious and sensing/driving effect sensitivity of structural strain sensing, for reduce influence as far as possible to intelligent piezo model structure adagio (1) natural mode of vibration, and the control requirement of suitable various control strategy, when distributing implantation piezoelectric sensing network (3) and Piezoelectric Driving network (2), adopt firm AB glue to paste, make that piezoelectric and intelligent piezo model structure adagio (1) secure bond are as a whole.

4. simulated intelligence flexible space sail board structural vibration main control test platform according to claim 1, it is characterized in that described DSP observing and controlling integrated circuit board (10) drives AD translation function, DA translation function, DMA transmission, and signal filtering and data analysis function, realize program modularity, guarantee the reliability and the portability of test platform software environment.

5. a simulated intelligence flexible space windsurfing active control in structural vibration test method adopts simulated intelligence flexible space sail board structural vibration main control test platform according to claim 1 to test, and it is characterized in that the operation steps of testing is as follows:

(1) adopts modal analysis method that the adagio structure is carried out the vibration characteristics analysis, obtain adagio structure each rank natural vibration frequency, and adopt vibrator frequency sweep method to revise each rank adagio structure natural vibration frequency than low-frequency range;

(2) download to DSP observing and controlling integrated circuit board according to the control algolithm coding, and the upper computer software platform is carried out the parameter setting, successfully back preparation beginning control is debugged in compiling;

(3) structural natural frequencies that obtains with reference to step (1) starts the exciting source signal generator, and the frequency and the amplitude of accumulation signal are set;

(4) position of adjustment vibrator starts vibrator, and intelligent piezo model structure adagio is carried out exciting;

(5) open charge amplifier, low-pass filter, oscillograph, obtain and nurse one's health the structural vibration response signal;

(6) open the piezoelectric power amplifier that connects the Piezoelectric Driving network;

(7) according to the control algolithm of setting host computer operating platform control command is set, and start-up control;

(8) from oscillograph and host computer interface observation structure vibration control effect.

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