A PLC-based structural stress dynamic monitoring and hierarchical early warning control system

Abstract

The application discloses a kind of structure stress dynamic monitoring and hierarchical early warning control systems based on PLC, and relates to the technical field of bridge construction equipment safety monitoring.It includes multi-source distributed sensing acquisition module, PLC core collaborative management and control module, hierarchical early warning linkage execution module and global monitoring cloud end operation and management module.Through multi-source distributed sensing network synchronous acquisition bridge machine stress, displacement, attitude and environmental multidimensional data, after PLC filtering verification, contrast multistage safety threshold output hierarchical early warning instruction, drive differentiating sound and light alarm, and realize full-cycle data storage and stress trend analysis through cloud platform, solve the existing bridge machine monitoring dimension scattered, alarm no grade distinction, lack of historical data support safety research and judge problem, can let on-site personnel according to early warning level quickly match disposal measures, while supporting remote operation and maintenance and safety review, comprehensively improve the precision of construction safety management and control.

Description

Technical Field

[0001] The present invention relates to the technical field of safety monitoring for bridge construction equipment, and particularly relates to a PLC-based structural stress dynamic monitoring and graded early warning control system. Background Art

[0002] With the continuous development of the scale of bridge engineering construction and construction technology, movable formwork bridge erecting machines have become the core equipment for segmental cast-in-place construction of long-span concrete bridges, and their structural stress state and operation stability directly determine the safety of personnel and equipment at the construction site and the quality of engineering construction. In the whole construction processes such as walking displacement, concrete pouring, and static curing, key force-bearing parts such as front and rear slings, main girders, and reverse buckle wheels are prone to risks of stress overrun, structural deformation and even instability due to dynamic load changes, asynchronous walking, and extreme environmental factors. Therefore, real-time and accurate monitoring and early warning of structural stress, operation posture and environmental parameters is the core link of bridge construction safety management and control.

[0003] At present, the safety monitoring systems supporting bridge erecting machines generally have functional limitations and are difficult to meet the actual demands of refined construction management and control. The monitoring dimensions are scattered and the early warning mechanism is extensive. Most systems only independently collect a single parameter such as structural stress or walking displacement, and do not integrate multi-dimensional data such as spatial posture, environmental wind speed, temperature and humidity for collaborative analysis; and they generally adopt a single threshold over-limit alarm mode, which cannot distinguish the severity level of safety hazards, making it difficult for on-site management personnel to quickly match corresponding disposal measures according to the alarm, resulting in low risk response efficiency. The long-term stability of monitoring data is insufficient. In the outdoor construction environment, the temperature difference fluctuates greatly and on-site vibration is frequent, so sensors are prone to zero drift and temperature deformation interference during long-term operation. Most of the existing systems rely on manual regular on-site calibration operations, which not only brings heavy maintenance workload and high operation and maintenance costs, but also makes it difficult to detect hidden collection abnormalities in time, easily leading to inaccurate monitoring data and potential safety hazards. The monitoring parameters lack working condition adaptability and global management and control capabilities. Existing systems generally adopt a fixed collection frequency and unified early warning threshold, and cannot dynamically adjust the monitoring strategy according to the risk characteristics of different construction processes such as walking, pouring, and standing; and most of the monitoring data is only stored in local control equipment, lacking the capabilities of cloud centralized management, force trend analysis and early warning record tracing, making it difficult to support remote operation and maintenance and full-cycle safety management and control of equipment. Contents of the Invention

[0004] The purpose of the present invention is to provide a PLC-based structural stress dynamic monitoring and graded early warning control system, which solves the technical problems raised in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a PLC-based structural stress dynamic monitoring and hierarchical early warning control system, comprising a multi-source distributed sensor acquisition module, a PLC core collaborative management module, a hierarchical early warning linkage execution module, and a full-domain monitoring cloud operation and maintenance management module; The multi-source distributed sensing acquisition module includes multiple sensor components deployed at the stress points of the bridge-building machine structure, the traveling mechanism, and the environmental monitoring points. It is connected to the signal acquisition port of the PLC core collaborative control module through an industrial fieldbus communication link to collect real-time data on structural stress, displacement, attitude, and environmental parameters. The PLC core collaborative control module is the core control unit of the system. It has a built-in data preprocessing program and a multi-level threshold comparison program. The data preprocessing program is configured to perform signal filtering and abnormal jump data removal on the collected data from each channel. The multi-level threshold comparison program has a built-in preset multi-level safety threshold parameter table. The multi-level safety threshold parameter table includes at least stress threshold, travel synchronization difference threshold, wind speed threshold, and temperature and humidity threshold. The multi-level threshold comparison program is configured to compare the preprocessed monitoring data with the corresponding level threshold and output graded early warning control commands. The graded early warning linkage execution module includes an audible and visual alarm device, which is connected to the switch output port of the PLC core collaborative control module and is configured to output audible and visual early warning signals of the corresponding level according to the graded early warning control command. The full-domain monitoring cloud operation and maintenance management module includes a wireless transmission unit and a cloud management platform. The wireless transmission unit is connected to the communication interface of the PLC core collaborative control module to realize bidirectional data transmission between the PLC core collaborative control module and the cloud management platform. The cloud management platform is used to store full-cycle monitoring data, perform stress trend analysis, and record and trace early warnings.

[0006] Preferably, the PLC core collaborative control module also has a built-in structural status dynamic verification and calibration program, which is configured with an independent redundant acquisition channel. The redundant acquisition channel shares the acquisition link with the sensor components in the multi-source distributed sensing acquisition module. The structural state dynamic verification and calibration program has a built-in verification sequence sorted by monitoring priority. It is configured to perform cyclic verification on the data collected at each point according to the verification sequence. By comparing the main acquisition channel data and redundant acquisition channel data of the same physical quantity, it identifies data drift and acquisition anomalies. When the verification detects data drift, a zero-point calibration operation is triggered; when the verification detects deviations caused by temperature, temperature compensation calibration is performed based on the temperature data collected by the temperature sensor in the multi-source distributed sensing acquisition module.

[0007] Preferably, the PLC core cooperative control module is further provided with a working condition adaptive parameter adjustment program, the working condition adaptive parameter adjustment program is provided with a parameter configuration table corresponding to different construction processes, and the parameter configuration table comprises acquisition frequency setting values and early warning threshold setting values corresponding to each construction process. The working condition adaptive parameter adjustment program is configured to call the corresponding setting values in the parameter configuration table according to the current construction process identification result, and adjust the acquisition frequency of each sensing point in the multi-source distributed sensing acquisition module and the corresponding early warning threshold in the multi-level threshold comparison program.

[0008] Preferably, the construction processes preset in the parameter configuration table at least include a walking process, a pouring process and a standing process. In the parameter configuration table corresponding to the walking process, the acquisition frequency setting value of the walking displacement related point is higher than the acquisition frequency setting value corresponding to the standing process; in the parameter configuration table corresponding to the standing process, the acquisition frequency setting value of the non-core point is lower than the acquisition frequency setting value corresponding to the walking process and the pouring process.

[0009] Preferably, the plurality of sensor components in the multi-source distributed sensing acquisition module specifically include: A vibrating wire surface strain gauge is arranged in the stress concentration area of the front sling, the rear sling and the reverse buckle wheel of the bridge machine, the vibrating wire surface strain gauge is provided with a temperature detection channel, and is used for acquiring structure micro-strain data and temperature data; A ring-shaped hollow force sensor is arranged at the position of the rear anchor sling, and is used for acquiring sling tension data; A pull rope type encoder is arranged at the walking oil cylinder of the diamond frame, and is used for acquiring walking displacement data; A dual-axis inclination sensor is arranged at the positions of the main beam, the bottom die and the upper front cross beam, and is used for acquiring spatial inclination data; A wind speed sensor and a temperature and humidity sensor are arranged at high points of the bridge machine, and are used for acquiring environmental parameters.

[0010] Preferably, the PLC core cooperative control module is provided with a temperature compensation algorithm and a walking synchronization difference comparison program; The temperature compensation algorithm is configured to read the temperature detection channel data of the vibrating wire surface strain gauge, and correct the stress calculation result; The walking synchronization difference comparison program is configured to read the displacement data of the pull rope type encoder at the two walking oil cylinders, calculate the absolute value of the difference, compare the absolute value of the difference with a preset walking synchronization difference threshold value, and trigger a walking synchronization early warning when the absolute value of the difference exceeds the threshold value.

[0011] Preferably, the sound and light alarm device in the hierarchical early warning linkage execution module is a rotating stroboscopic sound and light alarm. The multi-level safety threshold parameter table built in the multi-level threshold comparison program includes stress threshold, walking synchronization difference threshold, wind speed threshold and temperature and humidity threshold, and each level of threshold corresponds to different sound and light warning modes.

[0012] Preferably, the wireless transmission unit in the global monitoring cloud end operation and management module comprises a Zigbee wireless transmission module and a 4G communication module. The Zigbee wireless transmission module is used for wireless data transmission between the PLC core collaborative control module and the remote data aggregation terminal. The 4G communication module is used for remote data transmission between the PLC core collaborative control module and the cloud management platform.

[0013] Preferably, the local man-machine interaction terminal and the guide rail type switching power supply are further included. The local man-machine interaction terminal is an industrial touch screen, which is in communication connection with the PLC core collaborative control module, and the interface is divided into a real-time monitoring area, an environment monitoring area, a hoist load area, an inclination monitoring area and a historical data query area; the industrial touch screen supports manual operation of parameter setting, stress calibration and pre-alarm silencing, and operation instructions are transmitted to the PLC core collaborative control module for execution through the communication connection. The guide rail type switching power supply provides DC 24V power supply for the PLC core collaborative control module, the sensing component and the communication module.

[0014] Preferably, the sensing component and the transmission module arranged outdoors both have an IP65 or above protection level, and are integrated with a mechanical protection structure for wind and rain prevention and object fall prevention.

[0015] Compared with the related art, the structure stress dynamic monitoring and hierarchical pre-alarm control system based on PLC has the following beneficial effects: 1. The structure stress dynamic monitoring and hierarchical pre-alarm control system based on PLC synchronously collects bridge building machine stress, displacement, posture and environmental multi-dimensional data through a multi-source distributed sensing network, outputs hierarchical pre-alarm instructions by comparing the multi-level safety threshold after PLC filtering and verification, drives differentiated sound and light alarms, and realizes whole-cycle data storage and stress trend analysis through a cloud platform, thereby solving the problems of scattered monitoring dimensions, non-classified alarms, lack of historical data support for safety research and judgment of the existing bridge building machine, allowing field personnel to quickly match disposal measures according to the pre-alarm level, supporting remote operation and maintenance and safety review, and comprehensively improving the accuracy of construction safety control.

[0016] 2. The application provides a PLC-based structural stress dynamic monitoring and hierarchical early warning control system, which solves the problems of data drift, temperature deformation interference stress monitoring precision, high frequency of manual field calibration and high maintenance cost of outdoor sensors in long-term operation by using the PLC built-in structural state dynamic verification and calibration program, relying on independent redundant acquisition channels to verify the data of each point according to priority, automatically identifying data drift and temperature deviation and performing zero point calibration and temperature compensation respectively, and continuously guaranteeing the accuracy and reliability of monitoring data, effectively reducing the workload of field manual operation.

[0017] 3. The application provides a PLC-based structural stress dynamic monitoring and hierarchical early warning control system, which solves the problems of fixed monitoring parameters that cannot adapt to different working condition safety requirements, insufficient monitoring sensitivity of high-risk working conditions and excessive power consumption of redundant data of stable working conditions by matching the parameter configuration of three types of construction processes of walking, pouring and standing through the working condition adaptive parameter adjustment program, dynamically adjusting the sensing point acquisition frequency and the early warning threshold, ensuring the monitoring density of key parameters in the high-risk operation stage and reducing the operating load of non-core points in the standing stage, and balancing the construction monitoring safety and system operation economy. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The flowchart of the application; Figure 2 The expansion flowchart of the multi-source distributed sensing acquisition module of the application; Figure 3 The expansion flowchart of the PLC core collaborative control module of the application; Figure 4 The expansion flowchart of the hierarchical early warning linkage execution module of the application; Figure 5 The expansion flowchart of the global monitoring cloud operation and maintenance management module of the application; Figure 6 The expansion flowchart of the local interaction and supporting guarantee unit of the application. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application. EMBODIMENT

[0020] Please refer to Figures 1-6The application provides a technical scheme: a structure stress dynamic monitoring and hierarchical early warning control system based on a PLC, comprising a multi-source distributed sensing and collecting module, a PLC core cooperative management and control module, a hierarchical early warning linkage execution module and a global monitoring cloud operation and management module; The multi-source distributed sensing and collecting module comprises a plurality of sensor assemblies arranged at stress points of a bridge building machine structure, a running mechanism and environment monitoring points, and is connected to a signal collecting port of the PLC core cooperative management and control module through an industrial field bus communication link, and is used for collecting real-time data of structure stress, displacement, posture and environmental parameters; The plurality of sensor assemblies in the multi-source distributed sensing and collecting module specifically comprises: A vibrating wire surface strain gauge arranged at stress concentration areas of front and rear hangers and a reverse buckle wheel of the bridge building machine, the vibrating wire surface strain gauge being provided with a temperature detection channel and being used for collecting structure micro-strain data and temperature data; A ring-shaped hollow force sensor arranged at a rear anchor hanger position and used for collecting hanger tension data; A pull rope type encoder arranged at a running cylinder of a diamond frame and used for collecting running displacement data; A dual-axis inclination sensor arranged at positions of a main beam, a bottom die and an upper front cross beam and used for collecting spatial inclination data; A wind speed sensor and a temperature and humidity sensor arranged at high points of the bridge building machine and used for collecting environmental parameters; The PLC core cooperative management and control module is provided with a temperature compensation algorithm and a running synchronization difference value comparison program; The temperature compensation algorithm is configured to read temperature detection channel data of the vibrating wire surface strain gauge and correct stress calculation results; The running synchronization difference value comparison program is configured to read displacement data of the pull rope type encoder at the two running cylinders, calculate a difference absolute value, compare the difference absolute value with a preset running synchronization difference value threshold, and trigger a running synchronization early warning when the difference absolute value exceeds the threshold; In the embodiment, each sensor assembly adopts an RS485 bus interface, is connected to the signal collecting port of the PLC core cooperative management and control module through an industrial field bus in a ModbusRTU protocol, a single bus can be hung to a plurality of sensing devices, and the arrangement points cover five types of stress and monitoring areas of the main beam, the front and rear hangers, the reverse buckle wheel, the running mechanism and the high-altitude operation platform of the bridge building machine; The vibrating wire surface strain gauge is co-arranged 8, 3 are arranged in front and back hangers, and 2 are arranged in the position of the reverse buckle wheel. The temperature detection channel and the strain collection channel are synchronously sampled, and the default sampling period is 1s. The ring-shaped hollow force sensor is co-arranged 14, corresponding to all the stress points of the rear anchor hanger. The output signal is converted into a standard RS485 signal by the weighing transmitter and then connected to the collection link. The pull rope type encoder is co-arranged 2, which is installed at the walking oil cylinder on both sides of the diamond frame, with a measurement range of 0-2m and a measurement accuracy of 1mm. The dual-axis inclination sensor is co-arranged 6, one on the main beam, two on the front and rear of the bottom die, and one on the upper front cross beam, with an angle resolution of 0.01°. Two wind speed sensors and two temperature and humidity sensors are arranged, which are installed on the outside of the operating platform at the highest point of the bridge builder. The temperature compensation algorithm adopts a linear temperature correction model. The strain zero point offset at different temperatures is calibrated in advance. The temperature data is read in real time, and the micro-strain value is corrected by difference calculation to eliminate the interference of temperature deformation on the stress monitoring result. The walking synchronization difference comparison program reads the displacement data of the pull rope type encoder on both sides every 500ms, calculates the absolute value of the displacement difference of both sides, and triggers the corresponding level of walking synchronization warning when the absolute value of the difference exceeds the preset threshold for 3 consecutive sampling periods.

[0021] The PLC core collaborative management and control module is the system core control unit, which is built-in with data preprocessing program and multi-level threshold comparison program. The data preprocessing program is configured to filter signals and remove abnormal jump data for each collection data. The multi-level threshold comparison program is built-in with a preset multi-level safety threshold parameter table, which at least includes stress threshold, walking synchronization difference threshold, wind speed threshold and temperature and humidity threshold. The multi-level threshold comparison program is configured to compare the preprocessed monitoring data with the corresponding level of threshold, and output a graded warning control instruction. The PLC core collaborative management and control module is also built-in with a structure state dynamic verification and calibration program. The structure state dynamic verification and calibration program is configured with an independent redundant collection channel, which shares the collection link with the sensor components in the multi-source distributed sensing collection module. The structure state dynamic verification and calibration program is built-in with a verification sequence sorted by monitoring priority, which is configured to carry out cyclic verification on the collection data of each point according to the verification sequence. By comparing the main collection channel data and the redundant collection channel data of the same physical quantity, data drift and collection anomalies are identified. When the verification finds data drift, zero point calibration operation is triggered. When the verification finds deviation caused by temperature, temperature compensation calibration is performed combined with the temperature data collected by the temperature sensor in the multi-source distributed sensing collection module. The PLC core cooperative management and control module further has a working condition self-adaptive parameter adjustment program, the working condition self-adaptive parameter adjustment program has a preset parameter configuration table corresponding to different construction processes, and the parameter configuration table includes acquisition frequency set values and early warning threshold set values corresponding to each construction process; The working condition self-adaptive parameter adjustment program is configured to, according to a current construction process identification result, call corresponding set values in the parameter configuration table, and adjust the acquisition frequency of each sensing point in the multi-source distributed sensing acquisition module and the corresponding early warning threshold in the multi-stage threshold comparison program; The preset construction processes in the parameter configuration table at least include a walking process, a pouring process and a standing process; In the parameter configuration table corresponding to the walking process, the acquisition frequency set value of the walking displacement related point is higher than the acquisition frequency set value corresponding to the standing process; in the parameter configuration table corresponding to the standing process, the acquisition frequency set value of the non-core point is lower than the acquisition frequency set value corresponding to the walking process and the pouring process; In the present embodiment, the redundant acquisition channel of the structure state dynamic verification and calibration program adopts a primary and backup dual-acquisition channel design, shares the output signal of the same sensor with the primary acquisition channel, and realizes parallel data acquisition through an independent AD conversion unit; the verification sequence is sorted from high to low according to the safety priority of the monitoring point, and the sorting rule is: rear anchor belt tension point > front and rear belt stress point > walking displacement point > inclination point > environmental parameter point, and the cycle verification period is 10s, and the primary and backup channel data comparison of all core points is completed in each period according to the priority.

[0022] When the data deviation of the primary and backup channels exceeds the preset drift threshold and lasts for 2 verification periods, it is determined that the data drifts, and the PLC automatically triggers the zero point calibration instruction to reset the acquisition value under the current no-load state as the reference zero point; when the data deviation and the temperature change present a linear corresponding relationship, it is determined that the deviation is caused by the temperature, and the temperature compensation coefficient table is called to dynamically modify the primary channel data to complete the temperature compensation calibration.

[0023] The working condition self-adaptive parameter adjustment program supports two modes of manual process switching and automatic process identification, and the automatic identification mode judges the current construction process through the stress change amplitude and displacement change rate characteristics; in the parameter configuration table, the walking displacement point acquisition frequency set value under the walking process is 10Hz, and the stress point acquisition frequency set value is 2Hz; the stress point acquisition frequency set value under the pouring process is 5Hz, and the displacement point acquisition frequency set value is 1Hz; the core stress point acquisition frequency set value under the standing process is 0.5Hz, and the non-core environmental point acquisition frequency set value is 0.1Hz, and at the same time, the stress early warning threshold under the standing process is reduced by 15% compared with that under the walking process, so as to adapt to the structure safety boundary under different working conditions.

[0024] The hierarchical early warning linkage execution module comprises an audible and visual alarm device, the audible and visual alarm device is connected to a switching value output port of the PLC core cooperative control module, and is configured to output an audible and visual early warning signal of a corresponding level according to a hierarchical early warning control instruction; The audible and visual alarm device in the hierarchical early warning linkage execution module is a rotating stroboscopic audible and visual alarm device; The multi-level safety threshold parameter table in the multi-level threshold comparison program comprises stress thresholds, walking synchronization difference value thresholds, wind speed thresholds and temperature and humidity thresholds, and each level of threshold corresponds to a different audible and visual early warning mode; In this embodiment, the multi-level safety threshold parameter table sets three early warning levels, namely a first early warning, a second early warning and a third early warning; wherein the stress thresholds corresponding to the three levels of thresholds are 60%, 80% and 95% of the allowable stress, the walking synchronization difference value thresholds corresponding to the three levels of thresholds are 10 mm, 20 mm and 30 mm, the wind speed thresholds corresponding to the three levels of thresholds are 8 m / s, 10.8 m / s and 13.8 m / s, and the temperature and humidity thresholds are set according to three trigger conditions according to the Measures for the Management of Heatstroke Prevention and Cooling.

[0025] The rotating stroboscopic audible and visual alarm device sets a differentiated working mode corresponding to the three levels of early warning: the first early warning is yellow stroboscopic and intermittent beeping of a buzzer, with a 1 s beeping interval and a 3 s interval; the second early warning is orange stroboscopic and intermittent beeping of a buzzer at a fast rhythm, with a 0.5 s beeping interval and a 1 s interval; and the third early warning is red high-frequency stroboscopic and continuous beeping of a buzzer. The audible and visual alarm device is connected to a switching value output port of the PLC through a relay module, and the hierarchical early warning control instruction output by the PLC controls the power supply circuit and the stroboscopic mode of the alarm device through the on-off of the relay contact.

[0026] The global monitoring cloud operation and maintenance management module comprises a wireless transmission unit and a cloud management platform, the wireless transmission unit is connected to a communication interface of the PLC core cooperative control module, and is used to realize bidirectional data transmission between the PLC core cooperative control module and the cloud management platform; and the cloud management platform is used to store whole-cycle monitoring data, perform stress trend analysis and record early warning. The wireless transmission unit in the global monitoring cloud operation and maintenance management module comprises a Zigbee wireless transmission module and a 4G communication module; The Zigbee wireless transmission module is used for wireless data transmission between the PLC core cooperative control module and a remote data aggregation terminal; The 4G communication module is used for remote data transmission between the PLC core cooperative control module and the cloud management platform; In the embodiment, the Zigbee wireless transmission module adopts CC2630 chip scheme and works in the 2.4 GHz frequency band. The transmission distance can reach 1600 meters in a visible environment. The wireless data transmission between the PLC core collaborative control module and the remote data aggregation terminal and the local monitoring room in the construction site is used. The transmission content includes real-time monitoring data and local control instructions. The 4G communication module adopts a full-network industrial module. Through the Internet of Things card, the public network is accessed, and the two-way communication between the PLC and the cloud management platform is realized. The data upload period can be configured. The default real-time early warning data is uploaded in seconds, and the conventional monitoring data is uploaded in minutes. The cloud management platform adopts B / S architecture, supports multi-terminal permission access, and has full-cycle data storage, visual display, stress trend fitting analysis, early warning event recording and tracing functions. The stress trend analysis adopts a sliding window algorithm to automatically calculate the stress change curve within 24 hours and predict the stress development trend. Two-way data transmission supports cloud remote issuance of threshold parameters and calibration instructions to the site PLC to realize remote operation and maintenance control.

[0027] It also includes a local human-computer interaction terminal and a guide rail type switching power supply. The local human-computer interaction terminal is an industrial touch screen, which is in communication connection with the PLC core collaborative control module. The interface is divided into real-time monitoring area, environment monitoring area, sling load area, inclination monitoring area and historical data query area. The industrial touch screen supports manual operation of parameter setting, stress calibration and early warning mute. The operation instructions are transmitted to the PLC core collaborative control module through communication connection for execution. The guide rail type switching power supply provides DC 24V power supply for the PLC core collaborative control module, the sensing component and the communication module. In the embodiment, the industrial touch screen adopts a 10-inch resistive industrial touch screen, which is connected with the PLC core collaborative control module through the RS485 communication interface. The communication protocol is ModbusRTU. The real-time monitoring area of the interface displays the current values and state identifiers of all core points. The environment monitoring area displays real-time data of wind speed, temperature and humidity and corresponding wind level conversion results. The sling load area displays the tension values and load proportions of the front and rear slings. The inclination monitoring area displays the two-axis inclination data of each point in the form of numerical values and analog level meters. The historical data query area supports historical monitoring curves and warning records according to time range. The parameter setting, stress calibration, early warning mute operation are all set with operation permission verification, and the administrator password needs to be input before execution; the stress calibration operation is only allowed to trigger in the structure empty state, and after clicking the calibration button, the PLC automatically reads all the stress point data, and sets it as the zero reference value; the early warning mute operation only closes the current sound and light alarm buzzer, the stroboscopic warning is reserved, and the early warning is automatically released until the monitoring data falls below the safety threshold. The guide rail type switching power supply adopts AC220V input and DC24V output, and the total power meets the power supply demand of all field devices. The power supply loop is connected in series with an air switch and a surge protector, and has overcurrent, overvoltage and lightning protection.

[0028] The outdoor laid sensing components and transmission modules all have IP65 and above protection level, and are integrated with wind and rain proof, and mechanical protection structure against falling objects.

[0029] It should be noted that, in the present text, relational terms such as first and second and the like can only be used to distinguish one entity or action from another entity or action, without necessarily requiring or implying that there is any such actual relationship or order between these entities or actions. Moreover, the terms "comprises", "comprising" or any other variant thereof are intended to cover non-exclusive inclusions, so that a process, method, article or apparatus that includes a list of elements does not only include those elements, but also includes other elements not explicitly listed, or further includes elements inherent in such a process, method, article or apparatus. Without more limitations, the statement "comprises a limited element" does not exclude the presence of additional identical elements in the process, method, article or apparatus that includes the element.

[0030] Although embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and alterations can be made thereto without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A PLC-based structural stress dynamic monitoring and hierarchical early warning control system, characterized in that: It includes a multi-source distributed sensor acquisition module, a PLC core collaborative control module, a hierarchical early warning and linkage execution module, and a full-domain monitoring cloud operation and maintenance management module; The multi-source distributed sensing acquisition module includes multiple sensor components deployed at the stress points of the bridge-building machine structure, the traveling mechanism, and the environmental monitoring points. It is connected to the signal acquisition port of the PLC core collaborative control module through an industrial fieldbus communication link to collect real-time data on structural stress, displacement, attitude, and environmental parameters. The PLC core collaborative control module is the core control unit of the system. It has a built-in data preprocessing program and a multi-level threshold comparison program. The data preprocessing program is configured to perform signal filtering and abnormal jump data removal on the collected data from each channel. The multi-level threshold comparison program has a built-in preset multi-level safety threshold parameter table. The multi-level safety threshold parameter table includes at least stress threshold, travel synchronization difference threshold, wind speed threshold, and temperature and humidity threshold. The multi-level threshold comparison program is configured to compare the preprocessed monitoring data with the corresponding level threshold and output graded early warning control commands. The graded early warning linkage execution module includes an audible and visual alarm device, which is connected to the switch output port of the PLC core collaborative control module and is configured to output audible and visual early warning signals of the corresponding level according to the graded early warning control command. The full-domain monitoring cloud operation and maintenance management module includes a wireless transmission unit and a cloud management platform. The wireless transmission unit is connected to the communication interface of the PLC core collaborative control module to realize bidirectional data transmission between the PLC core collaborative control module and the cloud management platform. The cloud management platform is used to store full-cycle monitoring data, perform stress trend analysis, and record and trace early warnings.

2. The PLC-based structural stress dynamic monitoring and hierarchical early warning control system according to claim 1, characterized in that: The PLC core collaborative control module also has a built-in structural status dynamic verification and calibration program. The structural status dynamic verification and calibration program is configured with an independent redundant acquisition channel. The redundant acquisition channel shares the acquisition link with the sensor components in the multi-source distributed sensing acquisition module. The structural state dynamic verification and calibration program has a built-in verification sequence sorted by monitoring priority. It is configured to perform cyclic verification on the data collected at each point according to the verification sequence. By comparing the main acquisition channel data and redundant acquisition channel data of the same physical quantity, it identifies data drift and acquisition anomalies. When data drift is detected during verification, a zero-point calibration operation is triggered. When the verification detects a deviation caused by temperature, temperature compensation calibration is performed by combining the temperature data collected by the temperature sensor in the multi-source distributed sensing acquisition module.

3. The PLC-based structural stress dynamic monitoring and hierarchical early warning control system according to claim 1, characterized in that: The PLC core collaborative control module also has a built-in working condition adaptive parameter adjustment program. The working condition adaptive parameter adjustment program has a built-in parameter configuration table corresponding to different construction procedures. The parameter configuration table includes the acquisition frequency setting value and the early warning threshold setting value corresponding to each construction procedure. The adaptive parameter adjustment program is configured to call the corresponding set value in the parameter configuration table based on the current construction procedure identification result, and adjust the acquisition frequency of each sensing point in the multi-source distributed sensing acquisition module and the corresponding early warning threshold in the multi-level threshold comparison program.

4. The PLC-based structural stress dynamic monitoring and hierarchical early warning control system according to claim 3, characterized in that: The construction procedures preset in the parameter configuration table include at least the walking procedure, the pouring procedure, and the settling procedure; In the parameter configuration table corresponding to the traveling process, the sampling frequency setting value of the points related to the traveling displacement is higher than that corresponding to the stationary process; in the parameter configuration table corresponding to the stationary process, the sampling frequency setting value of the non-core points is lower than that corresponding to the traveling process and the pouring process.

5. The PLC-based structural stress dynamic monitoring and hierarchical early warning control system according to claim 1, characterized in that: The multiple sensor components in the multi-source distributed sensing acquisition module specifically include: Vibrating wire surface strain gauges are installed in the stress concentration areas of the front sling, rear sling, and reverse wheel of the bridge-building machine. The vibrating wire surface strain gauges have built-in temperature detection channels for collecting structural micro-strain data and temperature data. A ring-shaped hollow force sensor is installed at the rear anchor sling position to collect sling tension data; A pull-cord encoder is installed at the traveling cylinder of the diamond frame to collect traveling displacement data; Dual-axis tilt sensors are deployed at the positions of the main beam, bottom formwork, and upper front crossbeam to collect spatial tilt angle data; Wind speed and temperature / humidity sensors are installed at high points on the bridge-building machine to collect environmental parameters.

6. The PLC-based structural stress dynamic monitoring and hierarchical early warning control system according to claim 5, characterized in that: The PLC core collaborative control module has a built-in temperature compensation algorithm and a travel synchronization difference comparison program. The temperature compensation algorithm is configured to read the temperature detection channel data of the vibrating wire surface strain gauge and correct the stress calculation results; The travel synchronization difference comparison program is configured to read the displacement data of the rope encoders at the travel cylinders on both sides, calculate the absolute value of the difference, and compare the absolute value of the difference with a preset travel synchronization difference threshold. When the absolute value of the difference exceeds the threshold, a travel synchronization warning is triggered.

7. The PLC-based structural stress dynamic monitoring and hierarchical early warning control system according to claim 1, characterized in that: The audible and visual alarm device in the graded early warning linkage execution module is a rotating strobe-type audible and visual alarm. The multi-level threshold comparison program has a built-in multi-level safety threshold parameter table that includes stress threshold, travel synchronization difference threshold, wind speed threshold, and temperature and humidity threshold. Each level of threshold corresponds to a different sound and light warning mode.

8. The PLC-based structural stress dynamic monitoring and hierarchical early warning control system according to claim 1, characterized in that: The wireless transmission unit in the full-domain monitoring cloud operation and maintenance management module includes a Zigbee wireless transmission module and a 4G communication module. The Zigbee wireless transmission module is used for wireless data transmission between the PLC core collaborative control module and the remote data aggregation terminal. The 4G communication module is used for remote data transmission between the PLC core collaborative control module and the cloud management platform.

9. The PLC-based structural stress dynamic monitoring and hierarchical early warning control system according to claim 1, characterized in that: It also includes local human-computer interaction terminals and rail-mounted switching power supplies; The local human-machine interface terminal is an industrial touch screen, which is communicatively connected to the PLC core collaborative control module. The interface is divided into a real-time monitoring area, an environmental monitoring area, a sling load area, an tilt angle monitoring area, and a historical data query area. The industrial touch screen supports manual operation of parameter setting, stress calibration, and early warning silencing. The operation commands are transmitted to the PLC core collaborative control module for execution through the communication connection. The rail-mounted switching power supply provides DC24V power to the PLC core collaborative control module, sensing components, and communication module.

10. A PLC-based structural stress dynamic monitoring and hierarchical early warning control system according to claim 1, characterized in that: The outdoor-deployed sensing components and transmission modules all have an IP65 or higher protection rating and integrate a mechanical protective structure that is windproof, rainproof, and protected against falling objects.

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