1. A BIM-based wooden structure ancient building structure health monitoring method specifically comprises the following steps:

the method comprises the following steps: designing a wood structure historic building monitoring system based on-site investigation;

step two: creating a BIM (building information modeling) model with an IFC (interactive file sharing) format and containing damage information, and processing and calculating IFC model data;

step three: and establishing a real-time visual monitoring platform, and carrying out real-time monitoring and data updating on the wood structure ancient building structure.

2. The BIM-based wooden structure ancient building structure health monitoring method according to claim 1, characterized in that: the step one wood structure ancient building monitoring system comprises the following design steps: monitoring content determination and sensor type selection, sensor arrangement and early warning mechanism; the specific implementation method comprises the following steps:

1) monitoring content determination and sensor selection

For the current real situation of the wood structure ancient building to be monitored: carrying out on-site investigation on the age, historical protection data, geometric dimension, stress condition, damage condition, material and ambient temperature and humidity, determining the content of monitoring the stress condition of the structure and the ambient temperature and humidity, selecting corresponding sensor types such as nondestructive strain, displacement, inclination angle, vibration, temperature and humidity according to the monitored content, setting an early warning threshold of the sensor, and recording an alarm event of the sensor;

2) sensor optimization arrangement

Establishing a structural finite element analysis model and a temperature and humidity field simulation model according to the geometric dimension, damage condition, stress condition and surrounding environment temperature and humidity of the ancient building obtained by field investigation in the step 1), introducing the two models into structural finite element analysis software and temperature and humidity long simulation software for analysis to obtain a simulation result, analyzing structural weak points and bearing capacity of the ancient building to be monitored in the finite element analysis result, analyzing the position and influence degree of the environmental temperature and humidity in the temperature and humidity field simulation result on the ancient building, and arranging sensors at the structural weak points, the positions with large environmental influence and the positions with existing damage by combining the existing damage points found by field investigation;

3) establishing an early warning mechanism

And (3) calculating warning and danger two-stage early warning thresholds according to the ancient building bearing capacity, environment temperature and humidity limit value, bearing capacity and environment temperature and humidity checking and calculating formula given by ancient building wood structure reinforcement and maintenance standard and wood structure design standard according to the ancient building damage position to be monitored and the ambient temperature and humidity distribution condition obtained by structural finite element analysis and humiture field simulation in the step (2).

3. The BIM-based wooden structure ancient building structure health monitoring method according to claim 1, characterized in that: the second step is specifically as follows:

1) designing and creating a monitoring database by using an SQL Server, and storing the contents designed by the monitoring system in the step one, including monitoring contents, a sensor and early warning threshold information, in the monitoring database;

1.1) firstly taking the damage as a monitoring object, including ID, name, position and remarks, wherein each monitoring object is provided with a plurality of sensors and is associated with a plurality of routing inspection reports for demand analysis; the sensor comprises an ID number, a mounting position, mounting time, a sampling period, a two-stage early warning threshold value and remarks; each sensor has a designated type and a group of monitoring data based on time labels, and units and numerical values of the monitoring data are marked; one sensor can trigger multiple early warning events, and record the occurrence time, sensor number, trigger level, trigger monitoring value and processing work of the early warning events;

1.2) designing a conceptual structure, finding out entities from requirement analysis, confirming the relationship between corresponding entity attributes and the entities, and designing an E-R model diagram of a monitoring database;

1.3) carrying out logic structure design, and converting entities, attributes and relations in the E-R diagram finished in the concept structure design stage into corresponding data tables; designing a data table of a monitoring object, a sensor, monitoring data, an early warning event, an external document, a sensor type and a monitoring position according to the E-R diagram;

1.4) designing an authority account, wherein the authority account comprises the levels of tourists, managers and engineers which are respectively used by visitors, cultural and administrative departments and professional technical engineers;

2) according to the data obtained by the field survey in the step 1), building a BIM (building information modeling) containing damage information in Revit software, then deriving the BIM into an IFC (information processing) format, and developing an IFC model data processing algorithm through C # and C + + programming.

4. The BIM-based wooden structure ancient building structure health monitoring method according to claim 3, characterized in that: in the second step 2), an IFC model data processing algorithm is developed through C # and C + + programming, the algorithm comprises model data analysis, automatic updating and 3D display functions, and the specific development and implementation method is as follows:

analyzing the model data of the IFC file sequentially from the longitudinal and transverse aspects of the model, respectively extracting a data structure and semantic data from the IFC model, and displaying the data structure and the semantic data on a corresponding foreground control;

opening a model of a specified file path by using an IfcStore. open static method, then, starting to query all the contained items of the next level from the highest level, then, querying all the contained items of each sub-level, proceeding from top to bottom, completing longitudinal query, and then, laterally querying the attribute of each sub-item; storing the space items obtained by query in a memory, and sequentially retrieving the attribute and the relationship of each entity; in order to reduce the running memory, a click query method is adopted, and a query method is called to retrieve and display corresponding information by clicking each entity listed in a space structure on a control;

the query reading specified entity component is realized by linq (language Integrated query) and Lambda expression, and the implementation process is that a specified entity is firstly found by a known GUID, the expression of a query beam is "model. The Where rule may specify the type of attribute to be obtained;

the IFC model is automatically updated by searching an entity needing to be updated in the IFC model, calling corresponding data from a monitoring database and reading and writing the latest data into the IFC model through a Transaction processor 'Transaction';

the 3D presentation of the model has two aspects: the geometric shape of the component and the material rendering of the component are the first;

the method comprises the following steps that WpfMeshGeometry3D is used for loading geometric shapes of models, IPersistEntity.model.GeometryStore obtains geometric memory banks of the models, and a BeginRead () method reads all shape expression information and entity relative positions of the memory banks and returns the shape expression information and the entity relative positions to WpfMeshGeometry 3D;

the WPFMaterial is used for obtaining the color and the texture of the material of the component and returning to render and color the component in the scene; the color of the component material is obtained through XbaimColor, and the texture of the material is obtained through XbaimTexture and handed to a return object;

after rendering the geometric shape and the material of the model, creating a model loading scene through XbamScene < WpfMeshGeometry3D, WpfMaterial > scene ═ ILayyerStyler. BuildScene (), and filling the component into a loading environment by using XbamScene < WpfMeshGeometry3D, WpfMaterial >, so as to generate the 3D model.

5. The BIM-based wooden structure ancient building structure health monitoring method according to claim 1, characterized in that: the third step is specifically as follows:

1) developing a real-time visual monitoring platform through C # and T-SQL mixed programming: the development environment is that a Visual Studio 2019 development tool is used, a WPF window program is created based on a C # language NET development framework, corresponding controls are called to build a platform interface, and calling of various functions is achieved; the functional modules of the platform comprise monitoring project information management, real-time monitoring and early warning, monitoring management, IFC model management and system management functional modules; displaying and modifying the project information at the project information management function module; the real-time monitoring and early warning function module is used for displaying the monitoring data in real time and automatically alarming when the monitoring data exceeds the limit; checking and exporting monitoring data, checking, adding, modifying and deleting a sensor, checking, adding, modifying and deleting a monitoring object, and checking and remarking processing time of an early warning event in a monitoring management function module; the IFC model checking, model updating, model exporting and model importing are carried out on an IFC model management function module; user setting and authority management are carried out on the system management function module;

2) the real-time visual monitoring platform calls a monitoring database, a monitoring system consisting of monitoring content, a sensor, monitoring data and an early warning event is checked and exported through a monitoring management function module, the sensor is checked, added, modified and deleted, monitoring objects are checked, added, modified and deleted, and the early warning event is checked and remarked for processing time; the real-time updating and automatic alarming of the monitoring database are realized through the real-time monitoring and early warning function module;

3) importing a BIM model in an IFC format, and calling a data analysis function and a 3D display function of the IFC model data processing algorithm in the step two 2) to realize data display and 3D display of the BIM model in the IFC format; and calling a data modification function of the IFC model data processing algorithm in the step 2), and updating the BIM according to the imported monitoring data.

6. The BIM-based wooden structure ancient building structure health monitoring method according to claim 5, characterized in that: and step three, the real-time visual monitoring platform function module in the step 1) supports expansion.

7. The BIM-based wooden structure ancient building structure health monitoring method according to claim 5, characterized in that: and step three, the real-time visual monitoring platform supports importing and exporting the BIM with IFC standard issued by buildingSMART company as a data format.

Background

China historic building always uses timber structure as the main, and present protection work is mostly to be protected after the fact acutely, takes place to destroy promptly and then the corresponding measure of determining restores after the historic building takes place. According to the method, the ancient building timber structure cannot be comprehensively diagnosed, the overall and local stress conditions of the ancient building timber structure are obtained, and the established repairing method is just like patching and cannot be radically cured; and secondly, dangerous events cannot be predicted, and damage is prevented in advance. Thereby causing huge losses of cultural, historical, economic and social benefits.

In order to kill the damage event of the wooden structure ancient building in the cradle and preserve the value of the ancient building to the maximum extent, a great amount of Structural Health Monitoring (SHM-Structural Health Monitoring) application and research are carried out by protective personnel, and great help is provided for the protection work of the wooden structure ancient building. Such as monitoring the structure of a wooden tower in the area of Yingxian, monitoring the deformation of a Huqiu tower, and temple in Bao nationality. The national level continuously issues related policies, the monitoring work on ancient buildings is required to be strengthened, the preventive protection degree of the architecture heritage is improved, and the notice of the opinion on the protection and management work of strengthening the world cultural heritage indicates that a dynamic information system and a monitoring and early warning system for managing the world cultural heritage in China are to be built and strengthened as soon as possible. The revision 2020 of ancient building timber structure maintenance and reinforcement technology standard adds technical content about ancient building timber structure monitoring, and requires monitoring of the structure working condition and environmental impact according to the protection requirements.

However, the information level of the current SHM application is low, the utilization of the use value of monitoring data is limited, the information integration and interaction capabilities are poor, a technical method for integrated management of a monitoring system and an ancient wood structure body is lacked, and the real-time linkage of a digital model and an ancient building to be monitored cannot be realized, so that state information with high timeliness is provided for the work of protection personnel of all parties, and the requirement of preventive protection work for preventing the disease in the bud cannot be met.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention aims to provide a BIM-based method for monitoring the health of an ancient wooden building structure, which introduces BIM into the monitoring work of the structural health of the ancient wooden building structure, integrates the structural health monitoring into the whole BIM-based ancient wooden building structure protection system by virtue of the visual, multi-party cooperative and integrated functions of BIM technology, improves the utilization value of monitoring data and the timeliness of state information, and controls the development condition of the damage phenomenon in real time; the system has the advantages of no damage, quick operation, predictability, instantaneity and high expandability.

In order to achieve the purpose, the invention adopts the following technical scheme:

a BIM-based wooden structure ancient building structure health monitoring method specifically comprises the following steps:

the method comprises the following steps: designing a wood structure historic building monitoring system based on-site investigation;

step two: creating a BIM (building information modeling) model with an IFC (interactive file sharing) format and containing damage information, and processing and calculating IFC model data;

step three: and establishing a real-time visual monitoring platform, and carrying out real-time monitoring and data updating on the wood structure ancient building structure.

The step one wood structure ancient building monitoring system comprises the following design steps: monitoring content determination and sensor type selection, sensor arrangement and early warning mechanism; the specific implementation method comprises the following steps:

1) monitoring content determination and sensor selection

For the current real situation of the wood structure ancient building to be monitored: carrying out on-site investigation including year, historical protection data, geometric dimension, stress condition, damage condition, material and ambient temperature and humidity, determining the content monitored by the structural stress condition and the ambient temperature and humidity, selecting corresponding sensor types including nondestructive strain, displacement, inclination angle, vibration and temperature and humidity sensors according to the monitored content, setting early warning threshold values of the sensors, and recording alarm events of the sensors;

2) sensor optimization arrangement

According to the geometric dimension, damage condition, stress condition and ambient temperature and humidity of the ancient building obtained by site investigation in the step 1), establishing a structural finite element analysis model and a temperature and humidity field simulation model, introducing the two models into structural finite element analysis software and temperature and humidity long simulation software for analysis to obtain a simulation result, analyzing structural weak points and bearing capacity of the ancient building to be monitored in the finite element analysis result, analyzing the position and influence degree of the environmental temperature and humidity in the temperature and humidity field simulation result on the ancient building, and arranging sensors at the structural weak points, the positions with large environmental influence and the positions with existing damage by combining the existing damage points found by site investigation;

3) establishing an early warning mechanism

And (3) calculating warning and danger two-stage early warning thresholds according to the ancient building bearing capacity, environment temperature and humidity limit value, bearing capacity and environment temperature and humidity checking and calculating formula given by ancient building wood structure reinforcement and maintenance standard and wood structure design standard according to the ancient building damage position to be monitored and the ambient temperature and humidity distribution condition obtained by structural finite element analysis and humiture field simulation in the step (2).

The second step is specifically as follows:

1) designing and creating a monitoring database by using an SQL Server, and storing the contents designed by the monitoring system in the step one, including monitoring contents, a sensor and early warning threshold information, in the monitoring database;

1.1) firstly taking the damage as a monitoring object, including ID, name, position and remarks, wherein each monitoring object is provided with a plurality of sensors and is associated with a plurality of routing inspection reports for demand analysis; the sensor comprises an ID number, a mounting position, mounting time, a sampling period, a two-stage early warning threshold value and remarks; each sensor has a designated type and a group of monitoring data based on time labels, and units and numerical values of the monitoring data are marked; one sensor can trigger multiple early warning events, and record the occurrence time, sensor number, trigger level, trigger monitoring value and processing work of the early warning events;

1.2) designing a conceptual structure, finding out entities from requirement analysis, confirming the relationship between corresponding entity attributes and the entities, and designing an E-R model diagram of a monitoring database;

1.3) carrying out logic structure design, and converting entities, attributes and relations in the E-R diagram finished in the concept structure design stage into corresponding data tables; designing a data table of a monitoring object, a sensor, monitoring data, an early warning event, an external document, a sensor type and a monitoring position according to the E-R diagram;

1.4) designing an authority account, wherein the authority account comprises the levels of tourists, managers and engineers which are respectively used by visitors, cultural and administrative departments and professional technical engineers;

2) according to the data obtained by the field survey in the step 1), building a BIM (building information modeling) containing damage information in Revit software, then deriving the BIM into an IFC (information processing) format, and developing an IFC model data processing algorithm through C # and C + + programming.

In the second step 2), an IFC model data processing algorithm is developed through C # and C + + programming, the algorithm comprises model data analysis, automatic updating and 3D display functions, and the specific development and implementation method is as follows:

analyzing the model data of the IFC file sequentially from the longitudinal and transverse aspects of the model, respectively extracting a data structure and semantic data from the IFC model, and displaying the data structure and the semantic data on a corresponding foreground control;

opening a model of a specified file path by using an IfcStore. open static method, then, starting to query all the contained items of the next level from the highest level, then, querying all the contained items of each sub-level, proceeding from top to bottom, completing longitudinal query, and then, laterally querying the attribute of each sub-item; storing the space items obtained by query in a memory, and sequentially retrieving the attribute and the relationship of each entity; in order to reduce the running memory, a click query method is adopted, and a query method is called to retrieve and display corresponding information by clicking each entity listed in a space structure on a control;

the query reading specified entity component is realized by linq (language Integrated query) and Lambda expression, and the implementation process is that a specified entity is firstly found by a known GUID, the expression of a query beam is "model. The Where rule may specify the type of attribute to be obtained;

the IFC model is automatically updated by searching an entity needing to be updated in the IFC model, calling corresponding data from a monitoring database and reading and writing the latest data into the IFC model through a Transaction processor 'Transaction';

the 3D presentation of the model has two aspects: the geometric shape of the component and the material rendering of the component are the first;

the method comprises the following steps that WpfMeshGeometry3D is used for loading geometric shapes of models, IPersistEntity.model.GeometryStore obtains geometric memory banks of the models, and a BeginRead () method reads all shape expression information and entity relative positions of the memory banks and returns the shape expression information and the entity relative positions to WpfMeshGeometry 3D;

the WPFMaterial is used for obtaining the color and the texture of the material of the component and returning to render and color the component in the scene; the color of the component material is obtained through XbaimColor, and the texture of the material is obtained through XbaimTexture and handed to a return object;

after rendering the geometric shape and the material of the model, creating a model loading scene through XbamScene < WpfMeshGeometry3D, WpfMaterial > scene ═ ILayyerStyler. BuildScene (), and filling the component into a loading environment by using XbamScene < WpfMeshGeometry3D, WpfMaterial >, so as to generate the 3D model.

The third step is specifically as follows:

1) developing a real-time visual monitoring platform through C # and T-SQL mixed programming: the development environment is that a Visual Studio 2019 development tool is used, a WPF window program is created based on a C # language NET development framework, corresponding controls are called to build a platform interface, and calling of various functions is achieved; the functional modules of the platform comprise monitoring project information management, real-time monitoring and early warning, monitoring management, IFC model management and system management functional modules; displaying and modifying the project information at the project information management function module; the real-time monitoring and early warning function module is used for displaying the monitoring data in real time and automatically alarming when the monitoring data exceeds the limit; checking and exporting monitoring data, checking, adding, modifying and deleting a sensor, checking, adding, modifying and deleting a monitoring object, and checking and remarking processing time of an early warning event in a monitoring management function module; the IFC model checking, model updating, model exporting and model importing are carried out on an IFC model management function module; user setting and authority management are carried out on the system management function module;

2) the real-time visual monitoring platform calls a monitoring database, a monitoring system consisting of monitoring content, a sensor, monitoring data and an early warning event is checked and exported through a monitoring management function module, the sensor is checked, added, modified and deleted, monitoring objects are checked, added, modified and deleted, and the early warning event is checked and remarked for processing time; the real-time updating and automatic alarming of the monitoring database are realized through the real-time monitoring and early warning function module;

3) importing a BIM model in an IFC format, and calling a data analysis function and a 3D display function of the IFC model data processing algorithm in the step two 2) to realize data display and 3D display of the BIM model in the IFC format; and calling a data modification function of the IFC model data processing algorithm in the step 2), and updating the BIM according to the imported monitoring data.

And step three, the real-time visual monitoring platform function module in the step 1) supports expansion.

And step three, the real-time visual monitoring platform supports importing and exporting the BIM with IFC standard issued by buildingSMART company as a data format.

The invention has the beneficial effects that:

(1) the health condition of the wood structure ancient building is monitored by adopting the nondestructive wireless sensor, so that the ancient wood members cannot be damaged, and the cultural relic value of the ancient wood members cannot be influenced;

(2) the invention takes the damageable characteristic of the wooden structure ancient building into consideration, takes the damage as the monitoring object, establishes the early warning mechanism taking the damage as the basic unit, can achieve the goal and improve the cost performance of the monitoring activity;

(3) the design of the monitoring system of the invention considers the characteristics of the wood structure ancient building, from site investigation to structure analysis and temperature and humidity simulation, and then to the establishment of an early warning mechanism, the contents of monitoring content determination, sensor type selection, sensor arrangement, early warning threshold calculation and the like are completed step by step, and detailed guidance can be provided for workers;

(4) the invention realizes the automatic BIM model updating technology based on IFC standard, can automatically update the BIM model in the monitoring platform according to the monitoring data, and provides a digital model with high timeliness for other protection workers;

(5) the real-time visual monitoring platform developed by the invention takes the light IFC model as a data source, is fast to operate, occupies less computing resources and has good robustness;

(6) the real-time visual monitoring platform developed by the invention has high expandability, and can be used for more comprehensively monitoring the condition of the wooden structure ancient building by adding corresponding functional modules according to the actual monitoring work requirement;

(7) the real-time visual monitoring platform developed by the invention realizes integrated management of the BIM model and the monitoring system in the IFC format, and has high monitoring efficiency.

Drawings

Fig. 1 is a flow chart of the monitoring method according to the present invention.

FIG. 2 is a cloud view of finite element analysis of a structure according to the present invention.

FIG. 3 is a simulated cloud of the temperature field of the present invention.

FIG. 4 is a schematic diagram of the BIM model in IFC format according to the present invention.

FIG. 5 illustrates an IFC model auto-update logic in accordance with the present invention.

FIG. 6 is a diagram of an IFC model after being automatically updated according to the present invention.

FIG. 7 is a functional module of the real-time visual monitoring platform according to the present invention.

FIG. 8 is a user interface of the real-time visual monitoring platform according to the present invention.

FIG. 9 is a real-time monitoring interface of the real-time visual monitoring platform according to the present invention.

FIG. 10 is a diagram of an IFC model data display and 3D display interface according to the present invention.

Fig. 11 is a schematic view of the working principle of the monitoring method of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Referring to fig. 1, a BIM-based method for monitoring health of an ancient wood structure building structure specifically comprises the following steps:

the method comprises the following steps: designing a wood structure historic building monitoring system based on-site investigation;

step two: creating a BIM (building information modeling) model with an IFC (interactive file sharing) format and containing damage information, and processing and calculating IFC model data;

step three: and establishing a real-time visual monitoring platform, and carrying out real-time monitoring and data updating on the wood structure ancient building structure.

The step one wood structure ancient building monitoring system comprises the following design steps: monitoring content determination and sensor type selection, sensor arrangement and early warning mechanism; the specific implementation method comprises the following steps:

1) monitoring content determination and sensor selection

For the current real situation of the wood structure ancient building to be monitored: carrying out on-site investigation including year, historical protection data, geometric dimension, stress condition, damage condition, material and ambient temperature and humidity, determining the content monitored by the structural stress condition and the ambient temperature and humidity, selecting corresponding sensor types including nondestructive strain, displacement, inclination angle, vibration and temperature and humidity sensors according to the monitored content, setting early warning threshold values of the sensors, and recording alarm events of the sensors;

2) sensor optimization arrangement

Establishing a structural finite element analysis model (shown in figure 2) and a temperature and humidity field simulation model (shown in figure 3) according to the geometric dimension, damage condition, stress condition and ambient temperature and humidity of the ancient building obtained by field investigation in the step 1), importing the two models into structural finite element analysis software and temperature and humidity long simulation software for analysis to obtain a simulation result, analyzing the structural weak point and the bearing capacity of the ancient building to be monitored in the finite element analysis result, analyzing the position and the influence degree of the ambient temperature and humidity in the temperature and humidity field simulation result, greatly influencing the ancient building, and arranging a sensor at the structural weak point, the position with large environmental influence and the existing damage position by combining with the existing damage point discovered by field investigation;

3) establishing an early warning mechanism

And (3) calculating warning and danger two-stage early warning thresholds according to the ancient building bearing capacity, environment temperature and humidity limit value, bearing capacity and environment temperature and humidity checking and calculating formula given by ancient building wood structure reinforcement and maintenance standard and wood structure design standard according to the ancient building damage position to be monitored and the ambient temperature and humidity distribution condition obtained by structural finite element analysis and humiture field simulation in the step (2).

The second step is specifically as follows:

1) designing and creating a monitoring database by using an SQL Server, and storing the contents designed by the monitoring system in the step one, including monitoring contents, a sensor and early warning threshold information, in the monitoring database;

1.1) firstly taking the damage as a monitoring object, including ID, name, position and remarks, wherein each monitoring object is provided with a plurality of sensors and is associated with a plurality of routing inspection reports for demand analysis; the sensor comprises an ID number, a mounting position, mounting time, a sampling period, a two-stage early warning threshold value and remarks; each sensor has a designated type and a group of monitoring data based on time labels, and units and numerical values of the monitoring data are marked; one sensor can trigger multiple early warning events, and record the occurrence time, sensor number, trigger level, trigger monitoring value and processing work of the early warning events;

1.2) designing a conceptual structure, finding out entities from requirement analysis, confirming the relationship between corresponding entity attributes and the entities, and designing an E-R model diagram of a monitoring database;

1.3) carrying out logic structure design, and converting entities, attributes and relations in the E-R diagram finished in the concept structure design stage into corresponding data tables; designing a data table of a monitoring object, a sensor, monitoring data, an early warning event, an external document, a sensor type and a monitoring position according to the E-R diagram;

1.4) designing an authority account, wherein the authority account comprises the levels of tourists, managers and engineers which are respectively used by visitors, cultural and administrative departments and professional technical engineers;

2) according to the data obtained by the field survey in the step 1), a BIM (building information modeling) containing damage information is built in Revit software and then exported to be in an IFC (interactive information center) format (as shown in figure 4), and an IFC model data processing algorithm is developed through C # and C + + programming and comprises the functions of model data analysis, automatic updating and 3D display. The development of each function is realized as follows:

and the IFC file is analyzed sequentially from the longitudinal and transverse aspects of the model, the data structure and the semantic data are respectively extracted from the model, and the data structure and the semantic data are displayed on the corresponding foreground control.

Open the model of the appointed file path by using IfcStore. open static method, then query all the next level contained items from the highest level, then query all the contained items of each sub-level, go on from top to bottom, complete the longitudinal query, and then query the attribute of each sub-item horizontally. And storing the space items obtained by query in a memory, and sequentially retrieving the attribute and the relation of each entity. In order to reduce the running memory, a click query method is adopted, and a query method is called to retrieve and display corresponding information by clicking each entity listed in a space structure on a control.

The query reading specified entity component is realized by linq (language Integrated query) and Lambda expression, which is realized by firstly finding a specified entity by a known GUID, the expression of a query beam is "model. The Where rule may specify the type of attribute to be retrieved.

The automatic updating of the IFC model is realized by searching an entity needing to be updated in the IFC model, calling corresponding data from a monitoring database and reading and writing the latest data into the IFC model through a Transaction processor 'Transaction'. Taking a sensor as an example, the specific implementation logic of the automatic update algorithm is (as shown in fig. 5): 1) analyzing the loaded IFC model, finding out all IfcSensor entities and recording the GUID thereof; 2) writing the GUID into a corresponding sensor in a database, extracting monitoring parameters and returning the monitoring parameters to the IfcSensor; 3) finding the latest monitoring data of each sensor and returning the latest monitoring data together with the GUID; 4) writing the monitoring data into a corresponding IfcSensor entity according to the GUID; 5) and judging whether the monitoring data exceed a threshold value, and writing an early warning event into the IFC model and the monitoring database if the monitoring data exceed the threshold value. The automatically updated IFC model is shown in fig. 6.

The 3D presentation of the model has two aspects: the first is the geometry of the component, and the second is the material rendering of the component. The WpfMeshGeometry3D is used for loading the geometric shape of the model, IPersistEntity.model.GeometryStore obtains the geometric repository of the model, and the BeginRead () method reads all shape expression information and entity relative positions of the repository and returns the shape expression information and the entity relative positions to the WpfMeshGeometry 3D.

WPFMaterial is used to obtain the color and texture of the material of the building block and returns to rendering the building block in the scene. Wherein the color of the texture of the building block is obtained by XbaiColor and the texture of the texture is obtained by XbaiTexture and handed to the return object.

After rendering the geometric shape and the material of the model, creating a model loading scene through XbamScene < WpfMeshGeometry3D, WpfMaterial > scene ═ ILayyerStyler. BuildScene (), and filling the component into a loading environment by using XbamScene < WpfMeshGeometry3D, WpfMaterial >, so as to generate the 3D model.

The third step is specifically as follows:

1) a real-time Visual monitoring platform is developed through C # and T-SQL hybrid programming, a Visual Studio 2019 development tool is used as a development environment, a WPF window program is created through a C # language-based NET development framework, a corresponding control is called to build a platform interface, and calling of various functions is achieved. The functional modules of the platform comprise monitoring project information management, real-time monitoring and early warning, monitoring management, IFC model management and system management functional modules. As shown in fig. 7, the project information is displayed and modified in the project information management function module; the real-time monitoring and early warning function module is used for displaying the monitoring data in real time and automatically alarming when the monitoring data exceeds the limit; checking and exporting monitoring data, checking, adding, modifying and deleting a sensor, checking, adding, modifying and deleting a monitoring object, and checking and remarking processing time of an early warning event in a monitoring management function module; the IFC model checking, model updating, model exporting and model importing are carried out on an IFC model management function module; and carrying out user setting and authority management on the system management function module. The user operation interface of the real-time visual monitoring platform is shown in fig. 8;

2) and the real-time visual monitoring platform calls a monitoring database, a monitoring system consisting of monitoring contents, sensors, monitoring data and early warning events is managed through a monitoring management functional module, the specific management operation is as shown in step three 1), and the real-time updating and automatic alarming of the monitoring database are realized through a real-time monitoring and early warning functional module. The real-time monitoring interface is shown in fig. 9;

3) importing a BIM model in an IFC format, and calling a data analysis function and a 3D display function of the IFC model data processing algorithm in the step two 2) to realize data display and 3D display of the BIM model in the IFC format; and calling a data modification function of the IFC model data processing algorithm in the step 2), and updating the BIM according to the imported monitoring data. The IFC model data display and model 3D presentation are shown in fig. 10.

Step three, the functional module in step 1) supports extension.

And step three, the real-time visual monitoring platform supports importing and exporting the BIM with IFC standard issued by buildingSMART company as a data format.

Referring to fig. 11, the working principle of the present invention is:

the sensor system senses the state change of the wood structure ancient building to be monitored, monitoring data are stored in a monitoring database, and the content of the monitoring database further comprises monitoring content, a sensor, an early warning threshold value and other information; the monitoring platform calls a monitoring database through the T-SQL language and manages the monitoring database by using a monitoring management function; the monitoring platform calls the IFC model data processing algorithm developed in the step two 2) through the IFC model management function module, displays the information of the ancient building to be monitored contained in the IFC model on the monitoring platform through a data analysis function and a 3D display function, and visually checks the IFC model on the monitoring platform; the monitoring platform calls the IFC model data processing algorithm developed in the step 2), and updates corresponding data in the IFC model according to monitoring content, sensors and early warning threshold values contained in a monitoring database through a data modification function; the platform calls a real-time monitoring and early warning function, updates a monitoring database in real time, dynamically displays monitoring data and automatically alarms; the platform calls a data modification function of the IFC model data processing algorithm in the step 2) to update the IFC model according to the monitoring data through a model updating function under the IFC model management function module; and the staff takes corresponding protection measures for the wood structure ancient building according to the monitoring data.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.