CN201387385Y - Integrated piezoelectric multi-channel scanning structural health monitoring system based on computer bus - Google Patents

Abstract

The utility model discloses an integrated piezoelectric multi-channel scanning structural health monitoring system based on a computer bus, comprising a system power supply, a system bus backboard, a system controller card, a touch screen, an arbitrary waveform generation card, a high-speed data acquisition card, a high-speed Frequency power amplifier card, programmable gain charge amplifier card, sensor multi-channel switching card. In addition to the system power supply, the touch screen and each board are connected to the unified computer system bus backplane, and the boards and the system controller card communicate through the computer bus, and the touch screen directly communicates with the display interface of the system controller card. This system can perform multi-channel scanning on the piezoelectric excitation-sensing network, which is convenient for on-line structural health monitoring of large-scale engineering structures; the system is small in size, highly integrated, compact in structure, and easy to use; it has a unified integrated software system , can automatically extract common structural damage features, and damage discrimination; easy to operate, good online performance of system monitoring.

Description

Integrated piezoelectric multi-channel scanning structural health monitoring system based on computer bus

technical field

The utility model relates to a structural health monitoring system, in particular to a computer bus-based multi-channel scanning integrated system for controlling a piezoelectric excitation sensor network to realize structural health monitoring.

Background technique

Structural health monitoring technology is a new concept of intelligent material structure, which uses the advanced sensor/drive element network integrated in the structure to obtain information related to the health of the structure online and in real time (such as stress, strain, temperature, vibration mode, Wave propagation characteristics, etc.), combined with advanced signal information processing methods and material structure mechanics modeling methods, extract structural damage characteristic parameters, identify the state of the structure, including damage, and control the unsafe factors of the structure at an early stage to ensure Eliminate safety hazards or control the further development of safety hazards, so as to realize structural health self-diagnosis, ensure structural safety and reduce maintenance costs.

The structural health monitoring method based on active monitoring technology is a typical and effective hot research method. In this method, the driver (such as a piezoelectric element) embedded in the structure is generally used to actively excite the structure first, and the elastic wave is excited in the structure or the structure is in a slight vibration state, and at the same time, a single or multiple sensors (such as a piezoelectric element) are used to sense For the sensing signals at different positions of the structure, the damage in the structure will cause the change of the sensing signal. Based on the change, the damage in the structure can be judged and the state information of the structure can be obtained. There have been a large number of literatures in the world reporting the research progress of structural health monitoring methods based on active monitoring technology. These studies show that this method is effective and has important application prospects.

At present, the instruments used in the structural health monitoring method based on active monitoring technology are an instrument system consisting of multiple independent instruments built up by multiple independent instruments. The independent instruments included in this instrument system are: arbitrary waveform generator (function generator), broadband power amplifier, charge amplifier, computer data acquisition system or oscilloscope based on data acquisition card. These independent instruments and equipment use different software to work, which makes the instrument system software composed of them inconsistent, and it is extremely inconvenient for users to use. Each instrument must be manually adjusted, and this instrument system is caused by many independent instruments. The heavy hardware and many connections also make it inconvenient for users to use. Such an instrument system is not suitable for practical engineering applications. For example: the health monitoring of aircraft structure is currently an important field of structural health monitoring technology application. The health monitoring system applied to aircraft structure must be small in size, light in weight, easy to carry and install, and convenient for aircraft maintenance personnel to use; In health monitoring, the size of the health monitoring control room is limited, and there are other monitoring equipment, so the structural health monitoring system is also required to be small in size and easy to operate. For these requirements, existing instrument systems cannot meet. Therefore, it is urgent to develop a structural health monitoring system with high integration, small size, light weight and portability.

With the increasing development of engineering applications of structural health monitoring technology, the area of structures that need to be monitored for structural health monitoring is gradually increasing, and piezoelectric elements are more often used in the form of excitation-sensing network arrays. The existing instrument system is extremely inconvenient in the switching of each channel of the piezoelectric excitation-sensing network array. At this time, for the piezoelectric excitation-sensing network, the realization of the integrated piezoelectric multi-channel scanning structure health monitoring system based on the computer bus becomes very important.

Contents of the invention

1. Technical problem: The technical problem to be solved by the utility model is to provide a computer bus-based, miniaturized, integrated structural health monitoring system suitable for engineering applications, which is used to control the excitation-sensing network composed of piezoelectric elements Perform online health monitoring of structures.

2. Technical solution: In order to solve the above technical problems, the integrated piezoelectric multi-channel scanning structural health monitoring system based on computer bus of the present invention includes system power supply, system bus backplane, system controller card, touch screen, arbitrary waveform Generation card, high-speed data acquisition card, high-frequency power amplifier card, program-controlled gain charge amplifier card, sensor multi-channel switching card.

The system power supply, system bus backplane, system controller card, touch screen, arbitrary waveform generation card, high-speed data acquisition card, high-frequency power amplifier card, program-controlled gain charge amplifier card, sensor multi-channel switching card, and integrated software are integrated in the available Inside the integral aluminum alloy cooling case of the computer to prevent electromagnetic interference.

In addition to the system power supply, the touch screen and each board are connected to the unified computer system bus backplane, and the boards communicate with the system controller card through the bus, and the touch screen directly communicates with the display interface of the system controller card.

The system controller card transmits the excitation signal in the form of digital quantity to the arbitrary waveform generation card through the bus, and the arbitrary waveform generation card outputs the excitation signal in the form of analog quantity to the high-frequency power amplifier card through D/A conversion, and the high-frequency power amplifier card will After the power of the excitation signal is increased, it is transmitted to the sensor multi-channel switching card, and the sensor multi-channel switching card then inputs the excitation signal to the selected excitation piezoelectric element in the external piezoelectric excitation-sensing network; the external piezoelectric excitation-sensing network The sensing signal in the form of analog quantity generated by the selected sensing piezoelectric element is transmitted to the programmable gain charge amplifier card for amplification through the sensor multi-channel switching card, and the amplified sensing signal is converted by A/D through the high-speed data acquisition card After becoming a digital quantity, it is transmitted to the system controller card; the channel control signal generated by the system controller card is transmitted to the sensor multi-channel switching card through the bus to control it to switch channels, and monitor the channel switching status of the card at the same time; the system controller card The generated magnification control signal is transmitted to the programmable gain charge amplifier card through the bus to control its magnification and sensitivity, and at the same time monitor the control state of the card.

The system controller card is actually a computer system motherboard card, which includes basic modules such as CPU, memory, hard disk, and display control. The combination of the system controller card and the system bus backplane provides a unified computer bus platform for arbitrary waveform generation cards, high-speed data acquisition cards, program-controlled gain charge amplifier cards, and sensor multi-channel switching cards. The function of the system controller card is to process all system and application software, issue control commands to all hardware, and process all data results.

The function of the arbitrary waveform generation card is to generate a variety of excitation signals in active structural health monitoring. It can generate narrow-band Lamb waves, wide-band Lamb waves, sine waves, square waves, etc. Perform programming to generate various special excitation signals. The generated signal has a wide frequency range, which can be a signal in a continuous frequency range from DC to 5MHz. The signal amplitude can be continuously adjusted from 0 to ±10V, and has an output filter function. The voltage accuracy of the generated signal is high.

The high-frequency power amplifier card only uses the power provided on the bus and does not accept the control of the controller card. Its function is to increase the power of the excitation signal of the card generated by the arbitrary waveform. Due to the large area of the actual monitoring structure, the excitation signal of the card generated by the arbitrary waveform needs to pass through the high-frequency power amplifier card to increase the power of the excitation signal before inputting the piezoelectric excitation-sensing network. The working bandwidth of the high-frequency power amplifier card can reach -3dB bandwidth of 500KHz, and the output voltage can reach up to ±70V.

The sensor multi-channel switching card is a function to realize multi-channel scanning, and provides a stable and accurate channel switching function for the use of piezoelectric excitation-sensing networks in large-area structural health monitoring. It receives the high-frequency high-power excitation signal output by the high-frequency power amplifier card, sends it to the selected excitation element, and receives the sensing signal of the selected sensor element, and outputs it to the programmable gain charge amplifier card. The application and transmission of the excitation signal The collection of sensing signals has been effectively controlled in this module.

The function of the programmable gain charge amplifier card is to amplify the sensing signal of the piezoelectric excitation-sensing network. Its magnification and sensitivity can be adjusted through the program according to the needs of actual monitoring; its working bandwidth is from 15KHz to 500KHz.

The function of the high-speed data acquisition card is to collect high-speed data signals from the sensing signals of the excitation-sensing network composed of piezoelectric elements. Its sampling rate can reach 60MHz, and it has four simultaneous acquisition functions. Its high-speed and high-precision performance ensures the accuracy of sensing signals, thereby improving the accuracy and real-time performance of damage discrimination.

System power supply, system bus backplane, system controller card, arbitrary waveform generation card, high-speed data acquisition card, high-frequency power amplifier card, program-controlled gain charge amplifier card and sensor multi-channel switching card are integrated in the computer to prevent electromagnetic interference. Type aluminum alloy cooling case. Using this overall heat dissipation aluminum alloy chassis package, a stable, highly integrated, small size, light weight, and portable integrated piezoelectric multi-channel scanning structural health monitoring system can be realized.

The integral aluminum alloy heat dissipation shell is embedded with a system user interface (touch screen display) with touch screen function. The system user interface directly communicates with the system controller card through the system backplane to facilitate the user's operation and control of the system.

The integrated software used in this system includes three modules: software and hardware management module, signal feature extraction module and damage diagnosis module.

3. Beneficial effects: The integrated piezoelectric multi-channel scanning structural health monitoring system based on the computer bus of the utility model can conveniently perform multi-channel scanning on the piezoelectric excitation-sensing network, which is convenient for large-scale aerospace structures and civil structures. Realize online structural health monitoring: (1) This system provides efficient and stable channel switching, which is convenient for large-scale health monitoring of structures with piezoelectric excitation-sensing networks; (2) This system has stable performance, small size, High integration, compact structure, and easy to use; (3) This system has a unified integrated software system, which can automatically extract common structural damage features and identify damage; (4) has an easy-to-operate and flexible user interface, and It is very convenient to configure and expand structural health monitoring software and hardware; (5) The system has online long-term monitoring capabilities, which is conducive to promoting the practical application of active structural health monitoring technology in engineering.

Description of drawings

Fig. 1 is the overall structural representation of the utility model;

Fig. 2 is the overall structural diagram of the high-frequency power amplifier card of the present invention;

Fig. 3 is the schematic diagram of the realization module of the high-frequency power amplifier card power supply of the present invention;

Fig. 4 is the realization schematic diagram of the signal power amplification module of the high-frequency power amplifier card of the present invention;

Fig. 5 is the overall structural diagram of the program-controlled gain charge amplifier card of the present invention;

Fig. 6 is the realization schematic diagram of the program-controlled gain charge amplifier card bus communication module of the present utility model;

Fig. 7 is the realization principle diagram of the program-controlled gain charge amplifier card signal amplification module of the present invention;

Fig. 8 is an overall structural diagram of the sensor multi-channel switching card of the present invention;

Fig. 9 is a realization schematic diagram of the sensor multi-channel switching card bus communication module of the present invention;

Fig. 10 is a schematic diagram of the channel switching module of the sensor multi-channel switching card of the present invention;

Fig. 11 is a schematic diagram of the software structure of the utility model;

Fig. 12 is a flowchart of the system work of the present utility model.

Detailed ways

As shown in Figure 1, the PXI (PCI eXtension for Instrumentation, the expansion of PCI in the instrument field; PCI is the peripheral component interconnection standard, the full name Peripheral Component Interconnection) bus integrated piezoelectric multi-channel scanning structure of the present embodiment is healthy Monitoring system, including system power supply and system bus backplane. The system bus backplane is equipped with system controller card, touch screen, arbitrary waveform generation card, high-speed data acquisition card, high-frequency power amplifier card, program-controlled gain charge amplifier card, sensor It is a multi-channel switching card and communicates through the PXI bus, and also includes integrated piezoelectric multi-channel scanning structural health monitoring system software.

The system controller card transmits the excitation signal in digital form to the arbitrary waveform generation card through the bus. The system controller card is actually a computer system motherboard card, which includes basic modules such as CPU, memory, hard disk, and display control. The combination of the system controller card and the system bus backplane provides a unified computer bus platform for arbitrary waveform generation cards, high-speed data acquisition cards, program-controlled gain charge amplifier cards, and sensor multi-channel switching cards. The function of the system controller card is to process all system and application software, issue control commands to all hardware, and process all data results.

The arbitrary waveform generation card outputs the excitation signal to the high-frequency power amplifier card in the form of analog quantity through D/A conversion (digital-to-analog conversion). The function of the arbitrary waveform generating card is to generate a variety of excitation signals in active structural health monitoring. It can generate narrow-band Lamb waves, wide-band Lamb waves, sine waves, square waves, etc. It needs to be programmed to generate various special excitation signals. The signal frequency range it generates is wide, and it can be a signal in a continuous frequency range from DC to 5MHz. The signal amplitude can be continuously adjusted from 0 to ±10V, and it has output filtering. function, the voltage accuracy of the generated signal is high.

The high-frequency power amplifier card boosts the power of the excitation signal and transmits it to the sensor multi-channel switching card. The high-frequency power amplifier card only uses the power provided by the bus, and does not accept the control of the controller card. Its function is to increase the power of the excitation signal of the card generated by the arbitrary waveform. Due to the large area of the actual monitoring structure, the excitation signal of the card generated by the arbitrary waveform needs to pass through the high-frequency power amplifier card to increase the power of the excitation signal before inputting the piezoelectric excitation-sensing network. The working bandwidth of the high-frequency power amplifier card can reach -3dB bandwidth of 500KHz, and the output voltage can reach up to ±70V.

The sensor multi-channel switching card then inputs the excitation signal to the external piezoelectric excitation-sensing network. The excitation piezoelectric element, that is, the sensor array, is pasted on the structure to be monitored, where every two sensors in the sensor array can constitute an excitation- Sensing channels, a plurality of sensors can constitute a plurality of excitation-sensing channels to form an excitation-sensing network. The sensor multi-channel switching card is to realize the function of multi-channel scanning, and provides a stable and accurate channel switching function for the use of piezoelectric excitation-sensing network in large-area structural health monitoring. It receives the high-frequency high-power excitation signal output by the high-frequency power amplifier card, sends it to the selected excitation element, and receives the sensing signal of the selected sensor element, and outputs it to the programmable gain charge amplifier card. The application and transmission of the excitation signal The collection of sensing signals has been effectively controlled in this module.

External piezoelectric excitation - the response signal in analog form generated by the sensor piezoelectric element in the sensor network is transmitted to the programmable gain charge amplifier card for amplification through the sensor multi-channel switching card, and the amplified sensor signal is passed through the high-speed data acquisition card It is converted into a digital quantity through A/D conversion (analog-to-digital conversion) and then transmitted to the system controller card. The function of the high-speed data acquisition card is to collect high-speed data signals from the sensing signals of the excitation-sensing network composed of piezoelectric elements. Its sampling rate can reach 60MHz, and it has four simultaneous acquisition functions. Its high-speed and high-precision performance ensures the accuracy of sensing signals, thereby improving the accuracy and real-time performance of damage discrimination.

The channel control signal generated by the system controller card is transmitted to the multi-channel switching card of the sensor through the bus to control it to switch channels and monitor the channel switching status of the card at the same time; the amplification factor control signal generated by the system controller card is transmitted to the programmable gain sensor through the bus The charge amplifier card controls its amplification and sensitivity while monitoring the control status of the card. The function of the programmable gain charge amplifier card is to amplify the sensing signal of the piezoelectric excitation-sensing network. Its magnification and sensitivity can be adjusted through the program according to the needs of actual monitoring; its working bandwidth is from 15KHz to 500KHz.

The signal output amplitude, clock update rate of the arbitrary waveform generation card and the sampling frequency, sampling range, sampling length, trigger mode and level of the high-speed data acquisition card are controlled by the system controller card; the touch screen directly communicates with the system through the system bus backplane The controller card communicates to complete the task interaction between the user control command and the system controller card.

In this embodiment, the system power supply, system bus backplane, system controller card, touch screen, arbitrary waveform generation card, high-speed data acquisition card, high-frequency power amplifier card, program-controlled gain charge amplifier card, and sensor multi-channel switching card are all unified Integrated in the integral PXI aluminum alloy heat dissipation case that can prevent electromagnetic interference. PXI chassis with touch screen function, system power supply, system bus backplane, system controller card, arbitrary waveform generation card, and high-speed data acquisition card can be selected according to demand in the market.

As shown in Figure 2, the high-frequency power amplifier card is divided into two modules, namely a power supply module and a signal power amplification module. As shown in Figure 3, the power supply module increases the power supply voltage on the PXI bus, for example, converts the +12V power supply on the PXI bus to ±80V power supply, and supplies power to the signal power amplifier module. As shown in Figure 4, the power amplification module has two stages: the first stage is a voltage amplification stage, and the second stage is a current boost stage. The voltage amplification stage uses a high-speed integrated operational power amplifier circuit to amplify the voltage signal input by the arbitrary waveform generation card not exceeding ±10V/20mA to ±70V/50mA, and the current boost stage performs voltage following and boosts the current to 500mA, and finally outputs the largest signal The voltage/current is ±70V/500mA, and the undistorted frequency can reach up to 500KHz.

As shown in Figure 5, the programmable gain charge amplifier card is divided into two modules, namely, the bus communication module and the signal amplification module. As shown in Figure 6, the bus communication module interacts with the user control program through the PXI bus and the system controller card, generates sensitivity and magnification program-controlled signals, and monitors the program-controlled status. As shown in Figure 7, the signal amplification module has four stages: the first stage is a charge amplification stage, the second stage is a program-controlled amplification stage, and a high-pass active filter, the third stage is a low-pass active filter stage, and the fourth stage is a is the reverse amplification stage.

As shown in Figure 8, the sensor multi-channel switching card is divided into two modules: a bus communication module and a channel switching module. As shown in Figure 9, the bus communication module interacts with the user control program through the PXI bus and the system controller card, generates channel switching control signals, and monitors the channel opening status. As shown in Figure 10, the channel switching module consists of relays and their drive circuits. The module is connected with a piezoelectric excitation-sensing network, a high-frequency power amplifier card, and a program-controlled gain charge amplifier card.

In this embodiment, the integrated PXI aluminum alloy heat dissipation shell is embedded with a system user interface (touch screen display) with a touch screen function. System operation and control.

The integrated software structure for realizing the system functions of this embodiment is shown in FIG. 11 . The specific instructions are as follows:

(1) Software main interface: it is the main interface of the entire integrated software, which is used to dynamically call the software and hardware management module, signal feature extraction module, and damage diagnosis module. The collected sensor signals and monitoring reports are also displayed here;

(2) Software and hardware management modules, including:

(a) Hardware self-test: Through this module, the system can obtain the hardware running status, including hardware control normal, hardware error and unrecognizable information;

(b) Excitation signal output control: This module is used to generate signals acting on the excitation components, and set the output amplitude, frequency and number of points of the signal in the interface, as well as the waveform type, including positive selection wave, modulation wave, etc.;

(c) Sensing signal acquisition control: This module is used to collect the signal received by the sensing element. In the module, set the basic parameters such as sampling frequency, number of sampling points, trigger acquisition level, multiple acquisition average, pre-acquisition and other basic parameters for data acquisition, and can select the acquisition mode and control the preservation of the acquisition signal;

(d) Charge amplifier control: This module is used to amplify the signal obtained by the sensing element. By setting the corresponding gain and sensitivity in the software, the signal amplification state of the amplifier hardware is controlled;

(e) Multi-channel scanning control: This module realizes the scanning work of multiple excitation-sensing channels through the switching of relays. The module cooperates with the control signal acquisition, relay switching, charge amplification, and excitation signal output modules to work. According to the excitation-sensing element list imported into the system, the scanning is carried out at certain time intervals. The data results obtained by scanning are saved in the form set by the user;

(f) Sensor network management: This module is used to establish and import the sensor network (stimulus-sensing list) before multi-channel scanning. In the module, the excitation sensing element is connected with the relay, and the excitation-sensing element pair is defined by custom or system, and the excitation-sensing channel definition for multi-channel scanning is derived;

(g) Signal query and playback: this module is used to call the saved data files, and playback and display the signals in selectable modes;

(h) Remote network control: This module is used to control the integrated system with another portable computer through a wide area network or a local area network;

(i) Software error handling: This module is used to handle all illegal operations of the user to ensure that the system will not crash;

(j) Help document for system use: This module provides help prompts and system maintenance precautions for using the entire system software and hardware in the form of a document list.

(3) Signal feature extraction module, including:

(a) Huang's Transformation: This module is used to decompose the empirical mode of the signal, extract the intrinsic mode function, and perform Hilbert analysis to obtain the Hilbert spectrum, instantaneous frequency and marginal spectrum energy of each mode function of the signal;

(b) Time-domain signal analysis: this module is used to calculate the energy, amplitude, mean, variance, and ringing times of the signal;

(c) Frequency domain signal analysis: This module is used to filter the signal, calculate the power spectrum and center frequency of the signal;

(d) Complex wavelet transform: This module is used to calculate the wavelet transform modulus and arrival time of the signal at a given center frequency.

(4) Damage diagnosis module, including:

(a) Phased array imaging: This module uses the characteristic parameters of the sensing signal array combined with the principle of phased array to perform damage imaging, and gives the damage report of whether the structure is damaged, the degree of damage and the location of the damage;

(b) Time-reversal imaging: This module uses the characteristic parameters of the sensing signal array combined with the time-reversal focusing principle to perform damage imaging, and gives the damage report of whether the structure is damaged, the type, degree and location of the damage;

The above signal feature extraction and damage diagnosis methods can be combined and selected according to the monitored structure and damaged object. As shown in Figure 12, the specific process of the system in this embodiment is as follows:

(1) Connect the signal lead-out line of the piezoelectric excitation-sensing network with the multi-channel switching card of the sensor; the output terminal of the arbitrary waveform generation card is connected to the first acquisition channel of the high-speed data acquisition card as the trigger signal of signal acquisition, and at the same time The output end is connected to the input end of the high-frequency power amplifier card; the output end of the high-frequency power amplifier card is connected to the sensor multi-channel switch card; the input end of the program-controlled gain charge amplifier card is connected to the sensor multi-channel switch card; the program-controlled gain charge amplifier The output end of the card is connected to the second acquisition channel of the high-speed data acquisition card;

(2) Start the system self-inspection program to automatically detect all the hardware of the system. If there is a problem (self-inspection fails), the location of the faulty hardware is given, and the user is prompted to check; if the self-inspection is passed, enter the following steps;

(3) The main interface of the integrated software is displayed on the touch screen: set the hardware control parameters; import the excitation-sensing network channel definition; set the signal feature extraction method; set the damage diagnosis method. Hardware control parameters mainly include: output excitation signal parameters, data acquisition parameters, program-controlled gain charge amplifier parameters, time synchronization information, etc.; the definition of the excitation-sensing network channel is defined by the sensor network management module in the integrated software according to the user's definition to generate or the user directly imports a previously generated stimulus-sensing network channel definition;

(4) The system controller card sends each parameter to the corresponding software module;

(5) The excitation signal output control module, the sensing signal acquisition module, the charge amplifier control module, and the multi-channel scanning control module generate corresponding control signals and data according to the incoming parameters.

(6) The system controller card sends the control signals and data generated by the above software modules to the corresponding hardware;

(7) The arbitrary waveform generation card outputs the excitation signal according to the waveform data; the high-frequency power amplifier card increases the power of the excitation signal and sends it to the sensor multi-channel switching card; the high-speed data acquisition card prepares to collect the sensing signal according to the acquisition parameters, and waits for the piezoelectric excitation-transmission The sensing channel is opened; the programmable gain charge amplifier card controls the amplifier multiple and sensitivity according to the amplifier control signal;

(8) Sensor multi-channel switching card for channel switching;

(9) The high-speed data acquisition card starts to collect the sensing signal of the sensing piezoelectric element;

(10) Judging whether the scanning is completed. If it is not finished, the sensor multi-channel switching card will switch the channel and continue the current round of scanning. If the scanning is completed, the system controller card sends the sensing data to the signal feature extraction module;

(11) The signal feature extraction module calls the signal feature extraction method set before according to the collected sensing data to extract its feature parameters;

(12) The damage diagnosis module calls the previously set damage diagnosis method according to the characteristic parameters to judge the structural damage state and generate a damage report;

(13) The system can monitor the health of the structure online. If the monitoring is stopped, the system will stop the scanning process, and the monitoring work will end. If it does not stop, the next round of scanning process will continue.

(14) After the scanning process stops, the user can perform other operations, such as data query and playback, call other signal feature extraction methods for signal processing, and use other damage diagnosis methods to identify structural damage, etc.

Claims (3)

1. An integrated piezoelectric multi-channel scanning structural health monitoring system based on a computer bus, characterized in that it includes a system power supply, a system bus backplane, a system controller card, a touch screen, an arbitrary waveform generation card, a high-speed data acquisition card, High-frequency power amplifier card, programmable gain charge amplifier card, sensor multi-channel switching card; The system controller card transmits the excitation signal in the form of digital quantity to the arbitrary waveform generation card through the bus; The arbitrary waveform generation card outputs the excitation signal to the high-frequency power amplifier card in the form of analog quantity through D/A conversion; The high-frequency power amplifier card increases the power of the excitation signal and transmits it to the sensor multi-channel switching card; The sensor multi-channel switching card then inputs the excitation signal to the selected excitation piezoelectric element in the external piezoelectric excitation-sensing network; External piezoelectric excitation - the sensing signal in the form of analog quantity generated by the selected sensing piezoelectric element in the sensor network is transmitted to the programmable gain charge amplifier card through the sensor multi-channel switching card for amplification, and the amplified sensing signal is passed through the high-speed The data acquisition card is converted into a digital quantity through A/D and then transmitted to the system controller card; The sensor multi-channel switching card receives the channel control signal transmitted by the bus and generated by the system controller card, controls it to perform channel switching, and monitors the channel switching status of the card at the same time; The programmable gain charge amplifier card receives the amplification factor control signal transmitted through the bus and generated by the system controller card, controls its amplification factor and sensitivity, and monitors the control state of the card at the same time. 2. The computer bus-based integrated piezoelectric multi-channel scanning structure health monitoring system according to claim 1, characterized in that, in addition to the system power supply, the touch screen and each board are connected to a unified computer system bus backplane, The boards communicate with the system controller card through the bus, and the touch screen directly communicates with it through the display interface of the system controller card. 3. The computer bus-based integrated piezoelectric multi-channel scanning structural health monitoring system according to claim 1, wherein the system power supply, system bus backplane, system controller card, touch screen, arbitrary waveform generation card , high-speed data acquisition card, high-frequency power amplifier card, program-controlled gain charge amplifier card, and sensor multi-channel switching card are integrated in the integral aluminum alloy cooling case of the computer that can prevent electromagnetic interference.

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