Bridge Health Monitoring System

Abstract

The present disclosure provides a bridge health monitoring system, which belongs to the field of bridge monitoring. The bridge health monitoring system includes a controller, a displacement sensor, an excitation module, and a signal processing module; the first end of the displacement sensor is connected to the excitation module, the second end of the displacement sensor is connected to the first end of the signal processing module, and the second end of the signal processing module is connected to the controller; the excitation module includes a pulse generating circuit, a pulse control circuit, a push-pull circuit, a transformer, and a feedback circuit; the pulse generating circuit is connected to the input end of the pulse control circuit, and the control end of the pulse control circuit is connected to the controller; the output end of the pulse control circuit is connected to the input end of the push-pull circuit, and the output end of the push-pull circuit is connected to the input end of the transformer; the output end of the transformer is connected to the pulse generating circuit through a feedback circuit. The present disclosure provides a bridge health monitoring system to improve the accuracy of bridge displacement monitoring.

Description

Technical Field

[0001] The present disclosure relates to the technical field of bridge monitoring, and in particular to a bridge health monitoring system. Background Art

[0002] With the rapid development of modern transportation networks, bridges, as important transportation hubs, are receiving more and more attention for their safety and stability. Real-time monitoring of bridge displacement has become one of the important means to ensure the safe operation of bridges. Among many sensor technologies, capacitive displacement sensors are widely used in monitoring bridge displacement due to their advantages such as high precision, high sensitivity and non-contact measurement.

[0003] In the actual monitoring of bridge displacement, capacitive displacement sensors face many challenges. One of the important issues is the stability of the excitation signal. Due to the complex and changeable working environment of the bridge, including temperature changes, humidity changes, electromagnetic interference and other factors, the stability of the excitation signal will be affected. Especially in severe climatic conditions, such as heavy rain and strong winds, the role of these factors is more obvious, which may cause the excitation signal to be distorted or fluctuate, affecting the measurement accuracy and stability of the capacitive displacement sensor, thereby affecting the accuracy of bridge displacement monitoring. Summary of the invention

[0004] The embodiments of the present disclosure provide a bridge health monitoring system to improve the accuracy of bridge displacement monitoring.

[0005] The embodiment of the present disclosure provides a bridge health monitoring system, including a controller, a displacement sensor, an excitation module, a signal processing module and a wireless communication module;

[0006] The first end of the displacement sensor is connected to the excitation module, the second end of the displacement sensor is connected to the first end of the signal processing module, the second end of the signal processing module is connected to the controller, and the controller is connected to the monitoring center through the wireless communication module;

[0007] The excitation module includes a pulse generating circuit, a pulse control circuit, a push-pull circuit, a transformer and a feedback circuit;

[0008] The pulse generating circuit is used to output a pulse signal, the pulse generating circuit is connected to the input end of the pulse control circuit, and the control end of the pulse control circuit is connected to the controller;

[0009] The output end of the pulse control circuit is connected to the input end of the push-pull circuit, the output end of the push-pull circuit is connected to the input end of the transformer, and the output end of the transformer is used to output an excitation signal;

[0010] The output end of the transformer is connected to the pulse generating circuit through the feedback circuit.

[0011] In an exemplary embodiment of the present disclosure, a temperature monitoring module is also included;

[0012] The temperature monitoring module is used to monitor the ambient temperature of the displacement sensor, and the temperature monitoring module is connected to the controller.

[0013] In an exemplary embodiment of the present disclosure, the excitation module includes a trigger U2, a switch tube Q1 and a switch tube Q2;

[0014] The input end of the trigger U2 is connected to the pulse generating circuit, the clock end of the trigger U2 is connected to the controller, the first output end of the trigger U2 is connected to the control end of the switch tube Q1, and the second output end of the trigger U2 is connected to the control end of the switch tube Q2;

[0015] The first end of the switch tube Q1 is connected to the first input end of the transformer, the second end of the switch tube Q1 is grounded, the first end of the switch tube Q2 is connected to the second input end of the transformer, the second end of the switch tube Q2 is grounded, and the third input end of the transformer is connected to the VCC power supply;

[0016] The first output end of the transformer is used to output an excitation signal, the second output end of the transformer is grounded, and the first output end of the transformer is connected to the pulse generating circuit through the feedback circuit.

[0017] In an exemplary embodiment of the present disclosure, the excitation module further includes a pulse controller U1, a resistor R2 and a capacitor C3;

[0018] The power supply end of the pulse controller U1 is connected to the VCC power supply, the feedback end of the pulse controller U1 is connected to the feedback circuit, the reference end of the pulse controller U1 is grounded through the resistor R2, the adjustment end of the pulse controller U1 is grounded through the capacitor C3, and the output end of the pulse controller U1 is connected to the input end of the trigger U2.

[0019] In an exemplary embodiment of the present disclosure, the excitation module further includes a resistor R3;

[0020] The first end of the resistor R3 is connected to the second end of the switch tube Q1 and the second end of the switch tube Q2, and the second end of the resistor R3 is grounded.

[0021] In an exemplary embodiment of the present disclosure, the excitation module further includes a variable resistor RP3, a diode D3 and a capacitor C6;

[0022] The first end of the variable resistor RP3 is connected to the first output end of the transformer, the second end of the variable resistor RP3 is grounded, the sliding end of the variable resistor RP3 is connected to the anode of the diode D3, the cathode of the diode D3 is grounded through the capacitor C6, and the cathode of the diode D3 is connected to the feedback end of the pulse controller U1.

[0023] In an exemplary embodiment of the present disclosure, the signal processing module includes an amplification circuit, a rectification circuit and a filtering circuit;

[0024] The input end of the amplifier circuit is connected to the second end of the displacement sensor, the output end of the amplifier circuit is connected to the input end of the rectifier circuit, the output end of the rectifier circuit is connected to the input end of the filter circuit, and the output end of the filter circuit is connected to the controller.

[0025] In an exemplary embodiment of the present disclosure, the amplifying circuit includes a capacitor C10, an amplifier U4, a resistor R17, a resistor R5, an amplifier U3, a capacitor C7, a capacitor C8, a resistor R6, a capacitor C9, a resistor R7, and a resistor R8;

[0026] The first end of the capacitor C10 is connected to the excitation module, the second end of the capacitor C10 is connected to the first end of the displacement sensor, the second end of the capacitor C10 is connected to the inverting input end of the amplifier U4, the non-inverting input end of the amplifier U4 is grounded, the output of the amplifier U4 is connected to the inverting input end of the amplifier U4 through the resistor R17, the output end of the amplifier U4 is connected to the non-inverting input end of the amplifier U3, the inverting input end of the amplifier U3 is grounded through the resistor R5, the output end of the amplifier U3 is connected to the second end of the displacement sensor, the output end of the amplifier U3 is connected to the first end of the resistor R7 through the resistor R8, the resistor R7 is grounded through the capacitor C9, and the second end of the resistor R7 is connected to the inverting input end of the amplifier U3;

[0027] The output end of the amplifier U3 is connected to the first end of the capacitor C7 through the capacitor C8, the first end of the capacitor C7 is grounded through the resistor R6, the second end of the capacitor C7 is connected to the inverting input end of the amplifier U3, and the output end of the amplifier U3 is connected to the controller.

[0028] In an exemplary embodiment of the present disclosure, the rectifier circuit includes an amplifier U5, a resistor R12, a diode D4, a diode D5, an amplifier U6, a resistor R11, a diode D6, and a diode D7;

[0029] The inverting input terminal of the amplifier U5 is connected to the output terminal of the amplifier circuit, the non-inverting input terminal of the amplifier U6 is connected to the output terminal of the amplifier circuit, the non-inverting input terminal of the amplifier U5 is grounded, the output terminal of the amplifier is connected to the cathode of the diode D4, the anode of the diode D4 is connected to the inverting input terminal of the amplifier U5, the output terminal of the amplifier U5 is connected to the anode of the diode D5, and the cathode of the diode D5 is connected to the non-inverting input terminal of the amplifier U5 through the resistor R12;

[0030] The output end of the amplifier U6 is connected to the cathode of the diode D6, the anode of the diode D6 is connected to the inverting input end of the amplifier U6, the output end of the amplifier U6 is connected to the anode of the diode D7, the cathode of the diode D7 is connected to the inverting input end of the amplifier U6 through the resistor R11, and the cathode of the diode D5 and the cathode of the diode D7 are both connected to the filter circuit.

[0031] In an exemplary embodiment of the present disclosure, the filter circuit includes a resistor R13, a capacitor C12, a capacitor C13, a resistor R14, an amplifier U7, a resistor R16, and a resistor R15;

[0032] The first end of the resistor R13 is connected to the cathode of the diode D5 and the cathode of the diode D7, the second end of the resistor R13 is grounded through the capacitor C12, the second end of the resistor R13 is connected to the non-inverting input terminal of the amplifier U7 through the capacitor C13, the inverting input terminal of the amplifier U7 is grounded through the resistor R16, the output terminal of the amplifier U7 is connected to the inverting input terminal of the amplifier U7 through the resistor R15, and the output terminal of the amplifier U7 is connected to the controller.

[0033] The beneficial effects of a bridge health monitoring system provided by the embodiment of the present disclosure are as follows:

[0034] First, the pulse generation circuit, pulse control circuit, push-pull circuit and transformer in the excitation module work together to ensure that the output excitation signal is stable and reliable. This stable excitation signal is essential for the accurate measurement of the displacement sensor, thereby improving the accuracy of the overall monitoring system. Secondly, the feedback circuit monitors the excitation signal output by the transformer in real time and feeds this signal back to the pulse generation circuit. This feedback mechanism enables the system to adjust the output frequency of the excitation signal in real time to adapt to the complex and changing working environment and ensure the accuracy and stability of the monitoring data. Furthermore, the controller can send control instructions to the pulse control circuit according to the set time interval, and monitor the displacement of the bridge according to the set time interval. This design not only ensures the real-time monitoring, but also achieves energy-saving effects and reduces the operating costs of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0036] Figure 1 is a structural block diagram of a bridge health monitoring system provided by an embodiment of the present disclosure;

[0037] Figure 2 is a circuit diagram of an excitation module provided by an embodiment of the present disclosure;

[0038] Figure 3 is a circuit diagram of a signal processing module provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0039] In order to enable people in the technical field to better understand the present solution, the technical solution in the embodiment of the present solution will be clearly described below in conjunction with the drawings in the embodiment of the present solution. Obviously, the described embodiment is an embodiment of a part of the present solution, not all of the embodiments. Based on the embodiments in the present solution, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present solution.

[0040] The term "including" and any other variations in the specification and claims of this solution and the above drawings mean "including but not limited to", and is intended to cover non-exclusive inclusions and is not limited to the examples listed in the text. In addition, the terms "first" and "second" are used to distinguish different objects, not to describe a specific order.

[0041] The following is a detailed description of the implementation of the present disclosure in conjunction with the specific drawings:

[0042] Figure 1 A schematic diagram of the structure of a bridge health monitoring system provided by an embodiment of the present disclosure. Figure 1 ,The bridge health monitoring system includes a controller, a displacement sensor, an excitation module, a signal processing module and a wireless communication module;

[0043] The first end of the displacement sensor is connected to the excitation module, the second end of the displacement sensor is connected to the first end of the signal processing module, the second end of the signal processing module is connected to the controller, and the controller is connected to the monitoring center through the wireless communication module;

[0044] The excitation module includes a pulse generating circuit, a pulse controlling circuit, a push-pull circuit, a transformer and a feedback circuit;

[0045] The pulse generating circuit is used to output a pulse signal, the pulse generating circuit is connected to the input end of the pulse control circuit, and the control end of the pulse control circuit is connected to the controller;

[0046] The output end of the pulse control circuit is connected to the input end of the push-pull circuit, the output end of the push-pull circuit is connected to the input end of the transformer, and the output end of the transformer is used to output an excitation signal;

[0047] The output end of the transformer is connected to the pulse generating circuit through a feedback circuit.

[0048] In this embodiment, the displacement sensor can be a capacitive displacement sensor, which is installed at the key monitoring point of the bridge to monitor the small displacement changes of the bridge under the action of the excitation signal. The working principle of the capacitive displacement sensor is based on the change of capacitance. In the sensor, a fixed capacitor is used as a reference capacitor, and the capacitor connected to the bridge structure to be measured is used as a variable capacitor. When the bridge structure is displaced, the plate spacing or dielectric constant of the capacitor connected to it will change, resulting in a change in the capacitance value. By measuring this change, the displacement of the bridge can be accurately calculated.

[0049] The displacement sensor receives the excitation signal from the excitation module and converts it into an electrical signal related to the displacement of the bridge structure. This electrical signal reflects the actual displacement of the bridge structure.

[0050] In this embodiment, the excitation module is used to output a stable excitation signal. When the capacitive displacement sensor is working, an excitation signal needs to be applied to the capacitive displacement sensor. The excitation signal may be an AC signal.

[0051] The excitation module is composed of a pulse generating circuit, a pulse controlling circuit, a push-pull circuit, a transformer and a feedback circuit.

[0052] The pulse generating circuit is responsible for generating the original pulse signals, which are the basis for the subsequent circuit operation.

[0053] The pulse control circuit receives instructions from the controller. When the displacement of the bridge needs to be monitored, the controller sends a control signal to the pulse control circuit. The pulse control circuit is used to transmit the pulse signal output by the pulse generating circuit to the subsequent circuit. In this embodiment, the controller can send control instructions to the pulse control circuit according to the set time interval, and the displacement of the bridge can be monitored according to the set time interval, thereby achieving energy saving.

[0054] The push-pull circuit receives the pulse signal from the pulse control circuit and is used to improve the driving ability of the pulse signal, so that the pulse signal has higher energy and can drive the subsequent transformer to work.

[0055] The transformer receives the pulse signal with high driving capability output by the push-pull circuit and converts it into an AC excitation signal suitable for the displacement sensor. The excitation signal output by the transformer is sent to the displacement sensor.

[0056] When monitoring bridge displacement, the bridge health monitoring system is often exposed to the outside, and the working environment is complex and changeable, including temperature changes, humidity changes, electromagnetic interference and other factors, which will affect the stability of the excitation signal. Therefore, this embodiment adds a feedback circuit.

[0057] The feedback circuit monitors the excitation signal output by the transformer in real time and feeds this signal back to the pulse generating circuit. Through this feedback mechanism, the embodiment can adjust the output frequency of the excitation signal in real time to ensure the stability and accuracy of the excitation signal output by the transformer.

[0058] The signal processing module receives the electrical signal output by the displacement sensor and performs amplification, filtering and other processing on it to eliminate noise and interference and improve the signal-to-noise ratio.

[0059] The processed signal is converted into an analog or digital signal and sent to the controller. Data analysis is performed according to the preset algorithm and threshold. If the analysis results show that the bridge structure is abnormal or the displacement exceeds the safe range, the controller will trigger the alarm mechanism and send the relevant information to the remote monitoring center through the wireless communication module.

[0060] The wireless communication module is responsible for sending the data processed by the controller to the remote monitoring center. Through wireless communication, the remote monitoring center can understand the health status of the bridge in real time and take corresponding measures as needed.

[0061] From the above, it can be concluded that, firstly, the pulse generating circuit, pulse control circuit, push-pull circuit and transformer in the excitation module work together to ensure that the output excitation signal is stable and reliable. This stable excitation signal is essential for the accurate measurement of the displacement sensor, thereby improving the accuracy of the overall monitoring system. Secondly, the feedback circuit monitors the excitation signal output by the transformer in real time and feeds this signal back to the pulse generating circuit. This feedback mechanism enables the system to adjust the output frequency of the excitation signal in real time to adapt to the complex and changing working environment and ensure the accuracy and stability of the monitoring data. Furthermore, the controller can send control instructions to the pulse control circuit according to the set time interval, and monitor the displacement of the bridge according to the set time interval. This design not only ensures the real-time monitoring, but also achieves energy-saving effects and reduces the operating costs of the system.

[0062] like Figure 1 As shown, the bridge health monitoring system of the embodiment of the present disclosure further includes a temperature monitoring module; the temperature monitoring module is used to monitor the ambient temperature of the displacement sensor, and the temperature monitoring module is connected to the controller.

[0063] In this embodiment, the temperature monitoring module is used to continuously monitor the temperature of the displacement sensor and its surrounding environment. Since the output characteristics of the sensor will change with temperature, uncorrected temperature effects may cause measurement errors. Therefore, integrated temperature monitoring function is essential to ensure the accuracy and reliability of data.

[0064] Temperature monitoring modules usually contain high-precision temperature sensors (such as thermocouples, thermistors, or digital temperature sensors), which are sensitive to ambient temperature and can convert it into an electrical signal.

[0065] These temperature signals are sent to the controller, and the algorithm running in the controller uses this data to correct the raw displacement data obtained by the displacement sensor in real time, eliminating or reducing the measurement deviation caused by temperature changes.

[0066] The controller can dynamically adjust the compensation parameters of the signal processing module based on the received temperature information, ensuring stable measurement results that represent the true displacement change even under temperature fluctuations.

[0067] The temperature monitoring module is directly connected to the controller, which means that the temperature data it measures can be fed back to the controller in real time. This instant feedback mechanism enables the system to respond quickly to changes in ambient temperature and perform necessary data correction measures.

[0068] Through such a design, the bridge health monitoring system can not only effectively monitor the displacement changes of the bridge, but also ensure that these monitoring data remain highly accurate and reliable under different environmental conditions, further improving the overall efficiency and monitoring accuracy of the system.

[0069] like Figure 2 As shown, the excitation module of the embodiment of the present disclosure includes a trigger U2, a switch tube Q1 and a switch tube Q2; the input end of the trigger U2 is connected to the pulse generating circuit, the clock end of the trigger U2 is connected to the controller, the first output end of the trigger U2 is connected to the control end of the switch tube Q1, and the second output end of the trigger U2 is connected to the control end of the switch tube Q2; the first end of the switch tube Q1 is connected to the first input end of the transformer, the second end of the switch tube Q1 is grounded, the first end of the switch tube Q2 is connected to the second input end of the transformer, the second end of the switch tube Q2 is grounded, and the third input end of the transformer is connected to the VCC power supply; the first output end of the transformer is used to output an excitation signal, the second output end of the transformer is grounded, and the first output end of the transformer is connected to the pulse generating circuit through a feedback circuit.

[0070] In this embodiment, the trigger U2 constitutes the pulse control circuit in this embodiment, and the switch tube Q1 and the switch tube Q2 constitute the push-pull circuit in this embodiment. The working principle is as follows:

[0071] The trigger U2 can be a D trigger or an SR trigger, etc. In this embodiment, a D trigger is taken as an example. When the bridge displacement is monitored, the controller sends a high-level signal to the clock end of the trigger U2. The input end of the trigger U2 is used to receive the pulse signal output by the pulse generating circuit. When the pulse signal is high, the first output end of the trigger U2 outputs a high level and sends the high level to the control end of the switch tube Q1. The second output end of the trigger U2 outputs a low level and sends the low level to the control end of the switch tube Q2. The switch tube Q1 is turned on and the switch tube Q2 is turned off. At this time, the VCC power supply passes through the third input end of the transformer-the first input end of the transformer-the switch tube Q1 in sequence. When the pulse signal is low, the first output end of the trigger U2 outputs a low level, the second output end of the trigger U2 outputs a high level, the switch tube Q1 is turned off and the switch tube Q2 is turned on. At this time, the VCC power supply passes through the third input end of the transformer-the second input end of the transformer-the switch tube Q2 in sequence. Under the transformation of the pulse signal, the first output end of the transformer generates an AC excitation signal.

[0072] The transformer in this embodiment is Figure 2 Transformer T1 in.

[0073] The controller can send a high level signal to the clock terminal of the trigger U2 according to the set time interval, thereby achieving energy saving effect.

[0074] like Figure 2 As shown, the excitation module of the embodiment of the present disclosure also includes a pulse controller U1, a resistor R2 and a capacitor C3; the power supply end of the pulse controller U1 is connected to the VCC power supply, the feedback end of the pulse controller U1 is connected to the feedback circuit, the reference end of the pulse controller U1 is grounded through the resistor R2, the adjustment end of the pulse controller U1 is grounded through the capacitor C3, and the output end of the pulse controller U1 is connected to the input end of the trigger U2.

[0075] In this embodiment, the pulse generating circuit is mainly composed of a pulse controller U1, which is used to generate a pulse signal. The pulse controller U1 in this embodiment can adopt UC3842. When working, the output end (OUT pin) of the pulse controller U1 outputs a pulse signal.

[0076] like Figure 2 As shown, the excitation module of the embodiment of the present disclosure further includes a resistor R3; a first end of the resistor R3 is connected to a second end of the switch tube Q1 and a second end of the switch tube Q2, and a second end of the resistor R3 is grounded.

[0077] In this embodiment, the switch tube Q1 and the switch tube Q2 form a push-pull circuit for improving the driving ability of the pulse controller U1 to output the pulse signal. During operation, the current flowing through the switch tube Q1 and the switch tube Q2 cannot be too large, otherwise it will cause permanent damage to the switch tube Q1 and the switch tube Q2. For this reason, the pulse controller U1 can also monitor the current flowing through the switch tube Q1 and the switch tube Q2.

[0078] In this embodiment, the resistor R3 is connected in series between the second ends of the switch tube Q1, the switch tube Q2 and the ground. When the switch tube Q1 or the switch tube Q2 is turned on, a voltage will be generated on the resistor R3. The voltage on the resistor R3 can reflect the current flowing through the switch tube Q1 or the switch tube Q2. When the current exceeds the set value, the pulse controller U1 stops outputting the pulse signal, thereby avoiding damage to the switch tube Q1 or the switch tube Q2.

[0079] like Figure 2 As shown, the excitation module of the embodiment of the present disclosure also includes a resistor RP3, a diode D3 and a capacitor C6; the first end of the resistor RP3 is connected to the first output end of the transformer, the second end of the resistor RP3 is grounded, the sliding end of the resistor RP3 is connected to the anode of the diode D3, the cathode of the diode D3 is grounded through the capacitor C6, and the cathode of the diode D3 is connected to the feedback end of the pulse controller U1.

[0080] The variable resistor RP3, the diode D3 and the capacitor C6 constitute the feedback circuit in this embodiment. The variable resistor RP3 is used for voltage reduction, and the diode D3 and the capacitor C6 constitute a rectifier filter circuit, which is used to convert the AC excitation signal output by the transformer into a DC signal and send it to the feedback terminal (VFB pin) of the pulse controller U1. The pulse controller U1 can change the frequency of the output pulse signal according to the voltage at the feedback terminal, thereby adjusting the AC excitation signal output by the transformer, thereby ensuring the stability of the excitation signal.

[0081] like Figure 1 As shown, the signal processing module of the embodiment of the present disclosure includes an amplifier circuit, a rectifier circuit and a filter circuit; the input end of the amplifier circuit is connected to the second end of the displacement sensor, the output end of the amplifier circuit is connected to the input end of the rectifier circuit, the output end of the rectifier circuit is connected to the input end of the filter circuit, and the output end of the filter circuit is connected to the controller.

[0082] In this embodiment, the amplifier circuit is located at the front end of the signal processing flow, and its purpose is to enhance the weak signal output by the displacement sensor. Since the electrical signal converted by the physical change captured by the displacement sensor is often very weak, the amplifier circuit can effectively increase the signal strength for subsequent processing.

[0083] The rectifier circuit is immediately connected to the amplifier circuit. Since the excitation signal is an AC signal, the amplified electrical signal is also an AC signal. In order to facilitate the controller to identify it, the rectifier circuit converts the AC component into a DC signal.

[0084] The filter circuit is an important part of signal processing. It is mainly used to remove the noise and unnecessary frequency components that may remain in the amplification and rectification process to ensure that the signal output to the controller is pure and smooth. The filter circuit can be designed as a low-pass, high-pass or band-pass type, depending on the frequency range you want to retain or exclude to match the needs of displacement measurement.

[0085] The signal is amplified, rectified and then filtered from the displacement sensor. Each step is to optimize the signal quality and improve the accuracy and stability of the final measurement results. The signal processed by the filtering circuit has greatly improved purity and reliability, and is finally sent to the controller for analysis and decision-making.

[0086] like Figure 3 As shown, the amplifier circuit of the embodiment of the present disclosure includes a capacitor C10, an amplifier U4, a resistor R17, a resistor R5, an amplifier U3, a capacitor C7, a capacitor C8, a resistor R6, a capacitor C9, a resistor R7 and a resistor R8; the first end of the capacitor C10 is connected to the excitation module, the second end of the capacitor C10 is connected to the first end of the displacement sensor, the second end of the capacitor C10 is connected to the inverting input end of the amplifier U4, the inverting input end of the amplifier U4 is grounded, the output of the amplifier U4 is connected to the inverting input end of the amplifier U4 through the resistor R17, and the output end of the amplifier U4 is connected to the amplifier The in-phase input terminal of the amplifier U3 is connected to the non-inverting input terminal of the amplifier U3, the inverting input terminal of the amplifier U3 is grounded through the resistor R5, the output terminal of the amplifier U3 is connected to the second end of the displacement sensor, the output terminal of the amplifier U3 is connected to the first end of the resistor R7 through the resistor R8, the resistor R7 is grounded through the capacitor C9, and the second end of the resistor R7 is connected to the inverting input terminal of the amplifier U3; the output terminal of the amplifier U3 is connected to the first end of the capacitor C7 through the capacitor C8, the first end of the capacitor C7 is grounded through the resistor R6, the second end of the capacitor C7 is connected to the inverting input terminal of the amplifier U3, and the output terminal of the amplifier U3 is connected to the controller.

[0087] The displacement sensor in this embodiment is Figure 2 The displacement sensor CX in.

[0088] In this embodiment, capacitor C10 is used as a reference capacitor, amplifier U3 constitutes an amplifier circuit, amplifier U4 provides a bias voltage for the in-phase input terminal of amplifier U3, capacitor C7, capacitor C8, resistor R6, capacitor C9, resistor R7 and resistor R8 constitute a double T-type filter circuit as feedback of the amplifier circuit to reduce the influence of noise on the circuit. The amplified electrical signal is sent to the rectifier circuit.

[0089] like Figure 3 As shown, the rectifier circuit of the embodiment of the present disclosure includes an amplifier U5, a resistor R12, a diode D4, a diode D5, an amplifier U6, a resistor R11, a diode D6 and a diode D7; the inverting input terminal of the amplifier U5 is connected to the output terminal of the amplifier circuit, the non-inverting input terminal of the amplifier U6 is connected to the output terminal of the amplifier circuit, the non-inverting input terminal of the amplifier U5 is grounded, the output terminal of the amplifier is connected to the cathode of the diode D4, the anode of the diode D4 is connected to the inverting input terminal of the amplifier U5, the output terminal of the amplifier U5 is connected to the anode of the diode D5, and the cathode of the diode D5 is connected to the non-inverting input terminal of the amplifier U5 through the resistor R12; the output terminal of the amplifier U6 is connected to the cathode of the diode D6, the anode of the diode D6 is connected to the inverting input terminal of the amplifier U6, the output terminal of the amplifier U6 is connected to the anode of the diode D7, the cathode of the diode D7 is connected to the inverting input terminal of the amplifier U6 through the resistor R11, and the cathodes of the diode D5 and the diode D7 are both connected to the filter circuit.

[0090] In this embodiment, amplifier U5, resistor R12, diode D4, diode D5 and amplifier U6, resistor R11, diode D6 and diode D7 respectively constitute two separate half-wave rectifier circuits, which rectify the positive and negative half-cycle electrical signals respectively. The two separate half-wave rectifier circuits are connected in parallel to form a full-wave rectifier circuit, which finally converts the AC signal into a DC signal output.

[0091] This circuit connection method can reduce the impact of zero drift on the circuit and improve the stability of the circuit.

[0092] like Figure 3 As shown, the filtering circuit of the embodiment of the present disclosure includes a resistor R13, a capacitor C12, a capacitor C13, a resistor R14, an amplifier U7, a resistor R16 and a resistor R15; the first end of the resistor R13 is connected to the cathode of the diode D5 and the cathode of the diode D7, the second end of the resistor R13 is grounded through the capacitor C12, the second end of the resistor R13 is connected to the non-inverting input terminal of the amplifier U7 through the capacitor C13, the inverting input terminal of the amplifier U7 is grounded through the resistor R16, the output terminal of the amplifier U7 is connected to the inverting input terminal of the amplifier U7 through the resistor R15, and the output terminal of the amplifier U7 is connected to the controller.

[0093] In this embodiment, the filter circuit can adopt a bandpass filter circuit, wherein the resistor R13 and the capacitor C12 form a low-pass filter circuit, and the capacitor C13 and the resistor R14 form a high-pass filter circuit, which is used to remove the noise and unnecessary frequency components that may remain in the amplification and rectification process, and ensure that the signal output to the controller is pure and smooth.

[0094] The above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A bridge health monitoring system, characterized in that: It includes a controller, a displacement sensor, an excitation module, a signal processing module and a wireless communication module; The first end of the displacement sensor is connected to the excitation module, the second end of the displacement sensor is connected to the first end of the signal processing module, the second end of the signal processing module is connected to the controller, and the controller is connected to the monitoring center through the wireless communication module; The excitation module includes a pulse generating circuit, a pulse control circuit, a push-pull circuit, a transformer and a feedback circuit; The pulse generating circuit is used to output a pulse signal, the pulse generating circuit is connected to the input end of the pulse control circuit, and the control end of the pulse control circuit is connected to the controller; The output end of the pulse control circuit is connected to the input end of the push-pull circuit, the output end of the push-pull circuit is connected to the input end of the transformer, and the output end of the transformer is used to output an excitation signal; The output end of the transformer is connected to the pulse generating circuit through the feedback circuit; The controller sends a control instruction to the pulse control circuit according to a set time interval, and the controller monitors the displacement of the bridge according to the set time interval; the excitation module includes a trigger U2, a switch tube Q1 and a switch tube Q2; The input end of the trigger U2 is connected to the pulse generating circuit, the clock end of the trigger U2 is connected to the controller, the first output end of the trigger U2 is connected to the control end of the switch tube Q1, and the second output end of the trigger U2 is connected to the control end of the switch tube Q2; The first end of the switch tube Q1 is connected to the first input end of the transformer, the second end of the switch tube Q1 is grounded, the first end of the switch tube Q2 is connected to the second input end of the transformer, the second end of the switch tube Q2 is grounded, and the third input end of the transformer is connected to the VCC power supply; The first output terminal of the transformer is used to output an excitation signal, the second output terminal of the transformer is grounded, and the first output terminal of the transformer is connected to the pulse generating circuit through the feedback circuit; The excitation module also includes a pulse controller U1, a resistor R2 and a capacitor C3; The power supply end of the pulse controller U1 is connected to the VCC power supply, the feedback end of the pulse controller U1 is connected to the feedback circuit, the reference end of the pulse controller U1 is grounded through the resistor R2, the adjustment end of the pulse controller U1 is grounded through the capacitor C3, and the output end of the pulse controller U1 is connected to the input end of the trigger U2; The excitation module also includes a resistor R3; The first end of the resistor R3 is connected to the second end of the switch tube Q1 and the second end of the switch tube Q2, and the second end of the resistor R3 is grounded; The excitation module also includes a variable resistor RP3, a diode D3 and a capacitor C6; The first end of the variable resistor RP3 is connected to the first output end of the transformer, the second end of the variable resistor RP3 is grounded, the sliding end of the variable resistor RP3 is connected to the anode of the diode D3, the cathode of the diode D3 is grounded through the capacitor C6, and the cathode of the diode D3 is connected to the feedback end of the pulse controller U1.

2. The bridge health monitoring system according to claim 1, characterized in that: It also includes a temperature monitoring module; The temperature monitoring module is used to monitor the ambient temperature of the displacement sensor, and the temperature monitoring module is connected to the controller.

3. The bridge health monitoring system according to claim 1, characterized in that: The signal processing module includes an amplifier circuit, a rectifier circuit and a filter circuit; The input end of the amplifier circuit is connected to the second end of the displacement sensor, the output end of the amplifier circuit is connected to the input end of the rectifier circuit, the output end of the rectifier circuit is connected to the input end of the filter circuit, and the output end of the filter circuit is connected to the controller.

4. The bridge health monitoring system according to claim 3, characterized in that: The amplifying circuit includes capacitor C10, amplifier U4, resistor R17, resistor R5, amplifier U3, capacitor C7, capacitor C8, resistor R6, capacitor C9, resistor R7 and resistor R8; The first end of the capacitor C10 is connected to the excitation module, the second end of the capacitor C10 is connected to the first end of the displacement sensor, the second end of the capacitor C10 is connected to the inverting input end of the amplifier U4, the non-inverting input end of the amplifier U4 is grounded, the output end of the amplifier U4 is connected to the inverting input end of the amplifier U4 through the resistor R17, the output end of the amplifier U4 is connected to the non-inverting input end of the amplifier U3, the inverting input end of the amplifier U3 is grounded through the resistor R5, the output end of the amplifier U3 is connected to the second end of the displacement sensor, the output end of the amplifier U3 is connected to the first end of the resistor R7 through the resistor R8, the resistor R7 is grounded through the capacitor C9, and the second end of the resistor R7 is connected to the inverting input end of the amplifier U3; The output end of the amplifier U3 is connected to the first end of the capacitor C7 through the capacitor C8, the first end of the capacitor C7 is grounded through the resistor R6, the second end of the capacitor C7 is connected to the inverting input end of the amplifier U3, and the output end of the amplifier U3 is connected to the controller.

5. The bridge health monitoring system according to claim 4, characterized in that: The rectifier circuit includes an amplifier U5, a resistor R12, a diode D4, a diode D5, an amplifier U6, a resistor R11, a diode D6 and a diode D7; The inverting input terminal of the amplifier U5 is connected to the output terminal of the amplifier circuit, the non-inverting input terminal of the amplifier U6 is connected to the output terminal of the amplifier circuit, the non-inverting input terminal of the amplifier U5 is grounded, the output terminal of the amplifier is connected to the cathode of the diode D4, the anode of the diode D4 is connected to the inverting input terminal of the amplifier U5, the output terminal of the amplifier U5 is connected to the anode of the diode D5, and the cathode of the diode D5 is connected to the non-inverting input terminal of the amplifier U5 through the resistor R12; The output end of the amplifier U6 is connected to the cathode of the diode D6, the anode of the diode D6 is connected to the inverting input end of the amplifier U6, the output end of the amplifier U6 is connected to the anode of the diode D7, the cathode of the diode D7 is connected to the inverting input end of the amplifier U6 through the resistor R11, and the cathode of the diode D5 and the cathode of the diode D7 are both connected to the filter circuit.

6. The bridge health monitoring system according to claim 5, characterized in that: The filter circuit includes a resistor R13, a capacitor C12, a capacitor C13, a resistor R14, an amplifier U7, a resistor R16 and a resistor R15; The first end of the resistor R13 is connected to the cathode of the diode D5 and the cathode of the diode D7, the second end of the resistor R13 is grounded through the capacitor C12, the second end of the resistor R13 is connected to the non-inverting input terminal of the amplifier U7 through the capacitor C13, the inverting input terminal of the amplifier U7 is grounded through the resistor R16, the output terminal of the amplifier U7 is connected to the inverting input terminal of the amplifier U7 through the resistor R15, and the output terminal of the amplifier U7 is connected to the controller.

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