Climbing safety belt monitoring method based on work stage identification and spatial topology path

Abstract

The application discloses a climbing safety belt monitoring method based on a work stage identification and a space topology path, and the method comprises the following steps: acquiring work layer structure member space information and a hanging point coordinate, establishing a structure space model and a two-dimensional obstacle set; through collision detection of a falling swing track and the member, the basic protection area of each hanging point is determined in advance; according to a work personnel three-dimensional coordinate sequence, motion characteristics are extracted and the work stage is identified; in the fixed-point work or horizontal transfer stage, the actual path of the safety rope bypassing the obstacle is calculated, the effective swing fulcrum and the available rope length are determined, the basic protection area is corrected, and the effective protection area is obtained; according to the distance from the current position of the work personnel to the boundary of the effective protection area and the work stage, an alarm is implemented, and a hanging change prompt is sent when the distance is less than a pre-warning distance. The application can improve the accuracy of safety belt protection range judgment and hanging change prompt in a complex member environment.

Description

Technical Field

[0001] This application relates to the field of safety monitoring technology for high-altitude operations, specifically to a method for monitoring safety belts for high-altitude operations based on operation phase identification and spatial topology path. Background Technology

[0002] Working at heights is widespread in steel structure construction, power transmission tower erection, bridge installation, and equipment maintenance. To reduce the risk of falls, workers are typically required to wear safety harnesses and attach safety ropes to pre-set anchor points. Existing safety harness monitoring methods mostly focus on detecting whether the hook is connected, whether the working height exceeds a set value, or defining a fixed range of activity based on the anchor point location and safety rope length, issuing alarms when personnel cross the boundary or the safety rope becomes detached. Some systems also incorporate positioning devices to obtain the worker's location, enabling work trajectory recording and area monitoring.

[0003] However, in work environments with densely distributed steel beams, columns, and diagonal braces, safety ropes may bypass or overlap intermediate components. The actual path of the rope under stress is no longer a straight line between the anchor point and the worker, and the fall swing center and available rope length will also change accordingly. If the anchor point is still used as a fixed center for assessing the protection range, it can easily lead to deviations in the judgment of the actual safety boundary, making it difficult to accurately reflect the risk of a person colliding with surrounding components after a fall. Furthermore, the movement states and risk characteristics differ during climbing, horizontal transfer, fixed-point work, and descent. Using a uniform monitoring frequency and alarm rules may result in problems such as delayed alarms, frequent false alarms, or untimely re-anchoring prompts. Therefore, existing technologies still need to improve the accuracy of assessing the actual protective capability of safety ropes and conducting phased monitoring in complex structural environments. Summary of the Invention

[0004] This application provides a method for monitoring safety belts at heights based on work phase identification and spatial topology path, in order to at least solve some of the technical problems existing in the related technologies described above.

[0005] According to a first aspect of the embodiments of this application, a method for monitoring safety belts for climbing at heights based on work phase identification and spatial topology path is provided, comprising: acquiring spatial information of structural components and anchor point coordinates of the work layer, establishing a structural spatial model, and extracting the horizontal projection outer boundary of the components to form a two-dimensional obstacle set; for each anchor point, taking the anchor point as the swing center, and detecting the collision between the falling swing trajectory and the components to pre-calculate the basic protection area of ​​each anchor point; extracting motion features within a time window based on the three-dimensional coordinate sequence of the worker, and identifying the current work phase based on the motion features; when the work phase is a fixed-point work phase or a horizontal transfer phase, calculating the actual path of the safety rope around the obstacles based on the coordinates of the current connecting anchor point, the current coordinates of the worker, and the two-dimensional obstacle set, and determining an effective swing fulcrum based on the actual path; calculating the available rope length at the effective swing fulcrum based on the actual path, and correcting the basic protection area based on the available rope length using the effective swing fulcrum as a reference to obtain an effective protection area; calculating the distance from the current position of the worker to the boundary of the effective protection area, selecting an alarm strategy according to the work phase, and issuing a re-anchoring prompt when the distance is less than the warning distance.

[0006] As an optional approach, determining the effective swing fulcrum based on the actual path includes: when there are bends in the actual path, determining the bend closest to the worker as the effective swing fulcrum; when there are no bends in the actual path, determining the current connection point as the effective swing fulcrum.

[0007] As an optional approach, the calculation of the actual path of the safety rope around the obstacle includes: using the horizontal coordinates of the current connection point, the current horizontal coordinates of the worker, and the vertices of the convex hulls of each obstacle in the two-dimensional obstacle set as nodes of the visibility graph; for any two nodes, if the line connecting them does not pass through the interior region of any obstacle, then an edge is established, with the weight of the edge being the Euclidean distance between the two nodes; using the horizontal coordinates of the current connection point as the starting point and the current horizontal coordinates of the worker as the ending point, the shortest path is found on the visibility graph to obtain the actual path.

[0008] As an optional approach, the motion characteristics include the rate of change of height, the rate of horizontal movement, and the stability of horizontal movement direction; the rate of change of height is the ratio of the change in vertical coordinates within a time window to the length of the time window; the rate of horizontal movement is the ratio of the cumulative displacement of adjacent coordinate points on the horizontal plane within a time window to the length of the time window; and the stability of horizontal movement direction is the standard deviation of the difference in the horizontal displacement direction angles of adjacent segments within a time window.

[0009] As an optional approach, the operation phase includes a climbing phase, a descent phase, a horizontal transfer phase, and a stationary operation phase, determined sequentially according to the following priority order: when the rate of change of altitude is greater than the climbing rate threshold, it is determined to be the climbing phase; when the rate of change of altitude is less than the negative value of the descent rate threshold, it is determined to be the descent phase; when the absolute value of the rate of change of altitude is not greater than the climbing rate threshold, and the horizontal movement rate is greater than the horizontal movement rate threshold, and the horizontal movement directional stability is less than the directional stability threshold, it is determined to be the horizontal transfer phase; if none of the above conditions are met, it is determined to be the stationary operation phase.

[0010] As an optional approach, the pre-calculation of the basic protection area for each anchor point includes: taking sampling points at set intervals on a horizontal plane centered on the anchor point; for each sampling point, simulating the swing trajectory of a worker falling from that position with the anchor point as the center, and calculating the closest distance between the worker's body envelope and the enclosure of each structural component at each discrete position of the swing trajectory; when the closest distance is always greater than the safety margin throughout the swing process and the total fall height does not exceed the available clearance height below the working layer, marking the sampling point as an internal point of the basic protection area; traversing all sampling points, connecting the outer boundaries of all internal points to form a closed polygon, which serves as the basic protection area for that anchor point.

[0011] As an optional solution, the step of modifying the basic protection area according to the available rope length includes: translating the coordinates of each vertex of the polygon of the basic protection area along the direction from the current connection point to the effective swing fulcrum; using the ratio of the available rope length to the total length of the safety rope as a scaling factor, scaling the distance from each vertex of the translated polygon to the effective swing fulcrum according to the scaling factor to obtain the effective protection area.

[0012] As an optional approach, during the fixed-point operation phase, the calculation of the actual path of the safety rope around the obstacle and the calculation of the distance from the current position of the operator to the boundary of the effective protection area are performed at a first frequency; during the horizontal transfer phase, they are performed at a second frequency higher than the first frequency.

[0013] As an optional solution, when the operation phase switches to the horizontal transfer phase, step-by-step monitoring is activated to detect the connection status of the main rope and the backup safety rope. When both the main rope and the backup safety rope are disconnected, an audio alarm is issued. When the operation phase switches to the fixed-point operation phase, step-by-step monitoring is stopped.

[0014] According to a second aspect of the embodiments of this application, a height-climbing safety belt monitoring system based on work phase identification and spatial topology path is also provided, comprising: a structural space modeling module, used to acquire spatial information of structural components and anchor point coordinates of the work layer, establish a structural space model, and extract the horizontal projection outer boundary of the components to form a two-dimensional obstacle set; a basic protection area calculation module, used to pre-calculate the basic protection area of ​​each anchor point, with the anchor point as the swing center, through collision detection of the fall swing trajectory and the components; a work phase identification module, used to extract motion features within a time window based on the three-dimensional coordinate sequence of the worker, and identify the current work phase based on the motion features; and an actual path calculation module. The system comprises a safety rope module, which calculates the actual path of the safety rope around obstacles based on the coordinates of the current connection point, the current coordinates of the operator, and the set of two-dimensional obstacles when the operation phase is a fixed-point operation phase or a horizontal transfer phase, and determines the effective swing fulcrum based on the actual path; a protection area correction module, which calculates the available rope length at the effective swing fulcrum based on the actual path, and corrects the basic protection area based on the available rope length using the effective swing fulcrum as a reference to obtain the effective protection area; and an alarm module, which calculates the distance from the operator's current position to the boundary of the effective protection area, selects an alarm strategy according to the operation phase, and issues a replacement prompt when the distance is less than the warning distance.

[0015] This application identifies the climbing, descent, horizontal transfer, and fixed-point operation stages using the three-dimensional coordinate sequence of the operator, ensuring that the monitoring content, calculation frequency, and alarm methods match the actual operation status, reducing false alarms and delayed alerts caused by a unified monitoring strategy. During fixed-point operations and horizontal transfers, the actual path of the safety rope after bypassing obstacles is calculated by combining spatial information of structural components. The bend point closest to the operator is used as the effective swing fulcrum, reflecting the actual force situation where the swing center changes after the safety rope connects to steel beams, columns, or diagonal braces. Furthermore, the available rope length is determined based on the rope length consumed from the attachment point to the effective swing fulcrum, correcting the location and range of the pre-calculated basic protection area to make the effective protection area closer to the actual activity boundary after a fall. Based on this, boundary distance monitoring and reattachment alerts help to detect risks of personnel approaching or exceeding the actual protection range in advance, and improve the accuracy and timeliness of safety belt monitoring in complex structural environments.

[0016] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Furthermore, no embodiment in this disclosure is required to achieve all the effects described above. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0018] Figure 1 A flowchart illustrating a method for monitoring safety belts at heights based on work phase identification and spatial topology path, provided in this embodiment of the disclosure; Figure 2 A flowchart illustrating the current work stage identification process provided in this embodiment of the disclosure; Figure 3 A flowchart for determining an effective swing fulcrum provided in this embodiment of the disclosure; Figure 4 This is a flowchart illustrating the process of modifying the basic protection area according to an embodiment of the present disclosure. Figure 5 A schematic block diagram of a height-climbing safety belt monitoring system based on work phase identification and spatial topology path provided in this embodiment of the disclosure; Figure 6 This is a schematic block diagram of an electronic device provided in an embodiment of the present disclosure. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0020] This embodiment provides a method for monitoring safety belts at heights based on work phase identification and spatial topology path, applicable to high-altitude work scenarios with densely distributed structural components, such as steel structure construction, power transmission tower erection, and high-altitude bridge operations. The required site conditions for implementing this method include: deploying an Ultra-Wideband (UWB) positioning system in the work area, containing at least four positioning base stations covering the entire area of ​​the current work level; workers wearing UWB positioning tags on their waists, with the tags outputting three-dimensional coordinates, and a sampling frequency that can be configured, for example, twice per second; workers equipped with double-rope safety belts, including one main rope and one backup safety rope, each rope equipped with a shock absorber, the total length of the ropes and the maximum travel of the shock absorber being known parameters; several safety rope attachment points are set on the work surface according to construction specifications, and the three-dimensional coordinates of each attachment point have been measured and entered into the system during the construction preparation phase; near-field communication tags are installed at the safety belt hooks, and each attachment point is equipped with a corresponding reading device, allowing the system to obtain the currently connected attachment point number when the hook is connected to the attachment point; the building information model (BIM) data or three-dimensional laser scan data of the current work level has been acquired before the operation.

[0021] The implementation process of the method described in this application will be described in detail below with reference to specific embodiments. It should be noted that this embodiment is only used to explain this application and is not intended to limit the scope of protection of this application. Conventional adjustments or substitutions of each step by those skilled in the art without departing from the concept of this application should be included in the scope of protection of this application.

[0022] Please see Figure 1 , Figure 1 This is a flowchart of a method for monitoring safety belts at heights based on work phase identification and spatial topology path according to an embodiment of the present invention, such as... Figure 1 As shown, the method includes the following steps: S1: Obtain the spatial information of the structural components and the coordinates of the hanging points of the working layer, establish a structural spatial model, and extract the horizontal projection outer boundary of the components to form a two-dimensional obstacle set; S2, for each hanging point, with the hanging point as the swing center, the basic protection area of ​​each hanging point is pre-calculated by detecting the collision between the falling swing trajectory and the component; S3, based on the three-dimensional coordinate sequence of the operator, extract the motion features within the time window, and identify the current work stage based on the motion features; S4. When the operation stage is a fixed-point operation stage or a horizontal transfer stage, calculate the actual path of the safety rope around the obstacle based on the coordinates of the current connection point, the current coordinates of the operator and the two-dimensional obstacle set, and determine the effective swing fulcrum based on the actual path. S5. Calculate the available rope length at the effective swing fulcrum based on the actual path. Using the effective swing fulcrum as a reference, correct the basic protection area based on the available rope length to obtain the effective protection area. S6, calculate the distance from the current position of the operator to the boundary of the effective protection area, select an alarm strategy according to the operation stage, and issue a replacement prompt when the distance is less than the warning distance.

[0023] In some embodiments, for step S1, before the work begins, the structural component information of the current working layer is extracted from the BIM model or 3D scanning data. The extracted objects include the 3D coordinates, cross-sectional dimensions, and orientation of load-bearing components such as steel beams, columns, braces, and truss members. Each component is simplified as a cuboid bounding box or cylinder, represented by centerline coordinates and cross-sectional outer contour dimensions, thus forming the structural space model of the current working layer. Based on this, components whose height is between the hanging point height and the worker's waist height are selected from the above components. The outer boundary of its cross-section projected onto the horizontal plane is taken. Each cross-sectional outer boundary is represented by a 2D coordinate sequence of the convex hull vertex. All such cross-sectional outer boundaries constitute a set of 2D obstacles. Simultaneously, the 3D coordinates and numbers of all preset hanging points are recorded.

[0024] In some embodiments, for step S2, before the start of each work shift, for each anchor point of the current work layer, the basic protection area of ​​the anchor point is pre-calculated with the anchor point itself as the swing center. The basic protection area refers to the horizontal space range in which the safety rope can provide effective protection for the worker after a fall, under the ideal condition that the safety rope is in a straight line from the anchor point to the worker (i.e. the rope path has no intermediate detours).

[0025] Specifically, by hanging point Centered on the horizontal plane, at intervals Several sampling points are taken evenly along the radial direction. For example, taking 0.3 meters, for each sampling point This simulates the movement of a worker falling from this location. Let the height coordinates of the anchor point be... The height of the worker's safety belt connection point is The horizontal distance from the sampling point to the hanging point is The total length of the safety rope is The maximum stroke of the buffer is Free fall distance The calculation method is as follows: ;in The total length of the safety rope is expressed in meters (m). The horizontal distance from the sampling point to the hanging point is expressed in meters (m). and These are the height coordinates of the attachment point and the safety belt connection point, respectively, in meters (m). This refers to the freefall distance, measured in meters (m). Physically, it means the distance a worker falls vertically from the sampling point until the spatial distance to the hanging point is equal to... When the rope is taut, the vertical drop distance is... .when At that time, the sampling points had exceeded the horizontal range covered by the rope length and were directly marked outside the basic protection area; when the calculation results When this occurs, it indicates that the rope is taut or nearly taut at that position, allowing... The total height of the fall was The unit is meters (m).

[0026] After the rope is taut and the buffer is fully deployed, the workers use the anchor point as the center and... Imagine a circular arc with a radius of 0.5. Discretize this arc into several points with angular increments (e.g., 5 degrees). At each point, simplify the worker's body into an ellipsoid, centered on the safety harness connection point, with a semi-major axis of 0.3 meters, a semi-minor axis of 0.25 meters, and a semi-height axis of 0.8 meters. These dimensions are taken from commonly used adult human body dimensions in ergonomics. Calculate the shortest distance between this ellipsoid and the bounding boxes of all structural components within the current working level, and take the minimum value among all components. Safety margin. For example, take 0.5 meters, which is the sum of the maximum outward extension of a human limb and the collision buffer margin. Throughout the entire swing process, the closest distance between the ellipsoid and the bounding box of all components is always greater than... and the total height of the fall Not exceeding the available clearance height below the working level If the sampling point is within the basic protection zone, then it is considered a basic protection zone; otherwise, it is not.

[0027] After traversing all sampling points, the outer boundary points of the sampling points belonging to the basic protection area in each radial direction are taken and connected sequentially to form a closed polygon. This polygon is stored as a sequence of vertex coordinates and represents the basic protection area of ​​that hanging point. The available clearance height... Defined as the vertical distance between the bottom surface of the current working floor and the nearest obstacle below (such as the floor surface of the next lower level, the top surface of an installed structural beam, or the ground), in meters (m). This value is extracted from the BIM model to obtain the net clearance height below each area of ​​the current working floor, and the minimum value across all areas is taken as the total value for the entire floor. For a uniform value, if the BIM model does not include the information of the underlying structure, the height of the obstacles below each key location on the current working layer is measured on-site using a laser rangefinder, and the minimum value among the measured values ​​is taken.

[0028] Specifically, the calculation of the closest distance between the ellipsoid and the structural component's bounding box includes projecting the worker's body ellipsoid as an ellipse on the horizontal plane and an ellipse on the vertical plane. The structural component's bounding box uses an axis-aligned bounding box (AABB), calculated using the minimum coordinates. and maximum coordinates The shortest distance between the ellipsoid and the bounding box is defined and solved using the GJK algorithm (Gilbert-Johnson-Keerthi algorithm), which iteratively calculates the minimum distance between two convex sets. The ellipsoid is centered at the seatbelt connection point, and its semi-axis parameter is... , , Safety margin It has been embedded as a safe distance threshold in the termination condition of the GJK algorithm: when the distance returned by the GJK algorithm is greater than... If a point is deemed safe immediately, there's no need to calculate precise distance values, thus reducing computational overhead. In contrast, the GJK algorithm requires calculating support points in each iteration, and the ellipsoid is positioned in the direction vector... The coordinates of the support points on are ,in These are the coordinates of the center of the ellipsoid.

[0029] As an example, consider a suspension point located between two parallel steel beams, 4 meters apart, with the beams oriented east-west. After a 2-meter lateral movement in the north-south direction, the falling object's swing arc could sweep across the surface of the adjacent beams, resulting in a basic protection radius of only about 1.5 meters in the north-south direction. However, in the east-west direction, with no obstructions at the same distance, the protection range extends to the maximum horizontal distance allowed by the rope length. This difference in protection radius in different directions stems from the non-uniform distribution of structural components, thus forming irregular polygonal boundaries.

[0030] In some embodiments, for step S3, the high-altitude operation process includes stages with different characteristics such as climbing and ascending, fixed-point operation, horizontal transfer, and descent and evacuation. The movement patterns and fall risks of the workers in each stage are significantly different. In this embodiment, motion features are extracted from the three-dimensional coordinate sequence output by the UWB positioning tag to identify the current operation stage.

[0031] Specifically, please refer to Figure 2 , Figure 2 The diagram illustrates a flowchart for identifying the current work stage according to an embodiment of this disclosure. In block 201, motion features within a time window are extracted. The system continuously receives the three-dimensional coordinates output by the positioning tag. The sliding time window length is set to... For example, it can be configured to collect data for 15 seconds within the window. The coordinate point, the th coordinate point The coordinates of the points are as follows The corresponding sampling time is Three motion features were extracted from the sequence.

[0032] The first one is the rate of change of altitude. It reflects the vertical movement trend of the workers: ;in and These are the vertical coordinates of the last and first points within the window, respectively, in meters (m). The duration of the window is in seconds (s). The unit is meters per second (m / s), with positive values ​​indicating an increase and negative values ​​indicating a decrease.

[0033] The second is the horizontal movement speed. This reflects the level of activity of the workers on the horizontal plane. The numerator is the cumulative displacement of adjacent coordinate points on the horizontal plane within the window, in meters (m); the denominator is the window duration, in seconds (s). The unit is meters per second (m / s).

[0034] The third is stability in the horizontal direction of movement. This is used to distinguish between two movement modes: continuous walking along a fixed direction and irregular movement within a small area. Specifically, the horizontal displacement direction angle between adjacent coordinate points within the window is first calculated. ,in The range of values ​​is The unit is radians (rad). When the horizontal displacement between two adjacent points is less than the measurement accuracy of the positioning system (e.g., 0.1 meters), that segment of the orientation angle is unreliable and is discarded. For the retained orientation angle sequence, the difference between adjacent segments of the orientation angle is calculated. and normalized to interval, For all to be valid Standard deviation: ;in The number of effective direction angle differences. The mean, The unit is radians (rad). The smaller the value, the more stable the walking direction; the larger the value, the more frequently the direction changes.

[0035] It should be noted that when Calculate according to the above formula; when hour, Undefined, at this time The value is assigned to be twice the directional stability threshold (i.e. This means that the window does not meet the criteria for the horizontal transfer stage and is therefore treated as a fixed-point operation stage.

[0036] In box 202, the current operation stage is identified based on motion features. Based on the above three motion features, the operation process is divided into four states: climbing stage, descent stage, horizontal transfer stage, and fixed-point operation stage. These are determined in the following priority order: once a certain condition is met, the stage category is determined, and subsequent conditions are no longer checked.

[0037] Specifically, regarding the climbing phase: rate of altitude change Greater than the climbing rate threshold This means that the worker is climbing upwards. At this stage, the core task of the system is to monitor whether the height exceeds 2 meters. If the height difference between the vertical coordinate and the working platform surface exceeds 2 meters and the safety belt is not in a valid connection state, an audio reminder will be issued immediately.

[0038] Descent Phase: Rate of Altitude Change Negative values ​​less than the descent rate threshold This refers to the basic monitoring of the safety rope connection status as workers are evacuating downwards.

[0039] Horizontal transfer phase: high rate of change The absolute value is not greater than And horizontal movement speed Greater than the horizontal movement speed threshold And horizontal movement stability Less than the directional stability threshold The first condition excludes the possibility of climbing and descending, while the latter two conditions indicate that the workers are continuously walking in a fixed direction on a horizontal plane, i.e., transferring between attachment points.

[0040] Fixed-point operation phase: If any of the above conditions are not met, it is judged as the fixed-point operation phase, in which the operator basically stays in a fixed position to operate or moves back and forth within a small range.

[0041] in, and The climbing and descent rate thresholds are calibrated by measuring the climbing speed of workers on the target construction structure. As an example, several workers are organized to climb the steel ladder used on site, and the vertical coordinate changes over time are recorded using a UWB system. The mean and standard deviation of the vertical speed are statistically analyzed, and the mean minus 1.5 times the standard deviation is taken as the threshold. For example, if the measured mean is 0.52 m / s and the standard deviation is 0.14 m / s, then the threshold is... ,set up , Take the same value, for example, a range of 0.2 to 0.5 m / s. The horizontal movement rate threshold is used to distinguish between slight body swaying and active walking during stationary work.

[0042] As an example, the horizontal displacement rate of a worker tightening bolts at a height is measured, and the maximum value is recorded. A threshold value of 2 to 2.5 times this maximum value is used. For example, if the measured maximum value is 0.09 m / s, then... ,set up The value range is, for example, 0.15 to 0.3 m / s.

[0043] As an example, the directional stability threshold is measured when walking along a straight line along the steel beam and when operating in a small area in the node region. Typical values ​​are taken as the geometric mean of the two values ​​as the threshold. For example, approximately 0.15 rad for straight-line walking and approximately 1.1 rad for small-range operations, with a geometric mean of [missing value]. ,set up The value range is, for example, 0.3 to 0.6 rad.

[0044] Optionally, to avoid frequent stage jumps caused by positioning noise or short pauses, stability conditions for stage switching can be set, such as switching only when the judgment results are consistent for at least 3 consecutive time windows.

[0045] In some embodiments, for step S4, when the stage identification result is a fixed-point operation stage or a horizontal transfer stage, the system initiates the tracking calculation of the safety rope path. In densely populated environments, the safety rope is not always a straight line from the anchor point to the worker; when the worker moves within the coverage area of ​​the anchor point, the rope may drape over the surface of intermediate beams, columns, diagonal braces, etc., forming a bent path. If a fall occurs, the actual swing center after the rope is taut is not the far anchor point, but the last bend where the rope contacts the component. If the swing trajectory and protection range are calculated based on the anchor point position, a deviation will occur when the rope detours, and this deviation is more significant in environments with denser components.

[0046] In this embodiment, the bending position is referred to as the effective swing fulcrum. This refers to the bend in the safety rope that is closest to the worker and in contact with the surface of the component when the rope is taut. This point acts as the instantaneous swing center of the rope during the fall. ,in Actual path of the safety rope Current location of workers at medium distance The nearest bend point, when there are no bend points in the path. ; Two-dimensional horizontal coordinates Its coordinates belong to the current working plane range, at the hanging point To the current location of the worker They are distributed along the rope path.

[0047] Specifically, please refer to Figure 3 , Figure 3 A flowchart illustrating the determination of an effective swing fulcrum provided in an embodiment of this disclosure is shown. In block 301, the actual path of the safety rope around the obstacle is calculated based on a visibility graph method.

[0048] Specifically, the rope path problem is projected onto a horizontal plane for processing, where the horizontal coordinates of the current connection point are known. (Obtained from a table using the identification number obtained by the anchor point reading device) and the current horizontal coordinates of the operator. (Obtained from UWB positioning tags), and the convex hull contours of each obstacle in the two-dimensional obstacle set, the projection path of the safety rope on the horizontal plane is equivalent to... arrive The shortest taut rope path that bypasses all obstacles.

[0049] The visibility graph method is used to solve this problem. Visibility graphs are a standard method in computational geometry for handling shortest path problems with obstacle constraints. The principle is to construct a graph structure containing all possible bypass nodes and their connections that are not obscured by obstacles, and then search for the shortest path on the graph. The specific construction process involves... , The set of nodes is composed of the vertices of the convex hulls of all obstacles in the 2D obstacle set; for any two nodes, if the connecting line does not pass through the interior region of any obstacle, an edge is created, and the weight of the edge is the Euclidean distance between the two nodes. After the visibility graph is built, it is used as follows: Starting point Using Dijkstra's shortest path algorithm to find the destination, the path from the endpoint is determined. arrive The shortest path. Dijkstra's algorithm is a standard algorithm for finding the single-source shortest path in a non-negative weighted directed graph. It selects the node with the smallest cumulative distance from the starting point from the unvisited nodes in each step and performs a relaxation operation until the destination is reached or all nodes are visited.

[0050] Specifically, let the set of two-dimensional obstacles be... Each of the obstacles The vertices of the convex hull are stored as a two-dimensional coordinate sequence in counterclockwise order. The extraction method for convex hull vertices is as follows: for the rectangular bounding box of a structural member, the four corner points of the bottom face are taken as convex hull vertices; for a cylindrical member, eight points are taken at equal intervals along the circumference as convex hull vertices. Node set Including the starting point ,end And all obstacle convex hull vertices. For any node pair Determine line segments The method for determining whether a passage has passed through the interior of any obstacle is: traverse all obstacles. ,like or belong If the vertex is an obstacle, then the obstacle is not included in the occlusion judgment of its edge; otherwise, the line segment is detected. and Check if all edges intersect and if the intersection point is inside the two endpoints. If they do not intersect with any obstacle, or if the intersection point is exactly at the vertex of an obstacle, then an edge is created.

[0051] The input to Dijkstra's algorithm is a graph structure represented by an adjacency list. ,in Includes all valid edges and their weights; the output is from... arrive The shortest path node sequence is stored using a singly linked list data structure. When the number of obstacles exceeds 50, a local visibility graph strategy is adopted, i.e., only the starting point is retained. ,end The vertices of obstacles within a 5-meter radius are included in the graph. Obstacles outside the radius are sorted according to their projections along the line connecting the start and end points. Only obstacles whose projections cross the line are included in the calculation.

[0052] The resulting path is represented as an ordered sequence of nodes. ,in The bend point where the rope contacts the vertex of the obstacle's convex hull; if and There are no obstacles obstructing the path, and the path is a straight segment. There is no intermediate bend.

[0053] As an example, a certain hanging point The horizontal coordinate is (0, 0), and the position of the worker is... The coordinates are (6, 4), and there is an H-shaped steel beam between them. The horizontal projection of the cross section has a vertex with coordinates (3, 1.5). arrive The straight line passes through the interior of the beam section, but the rope path is not straight. The path is obtained by solving the shortest path problem using the visibility graph. The rope bends at (3, 1.5) when it comes into contact with the beam surface.

[0054] The number of obstacles within the operation layer typically ranges from tens to hundreds, with each obstacle's convex hull usually having 3 to 6 vertices, resulting in a total number of nodes not exceeding several hundred. The construction complexity of the visibility graph is O(n log n). , Given the total number of nodes, this can be completed in milliseconds. When the obstacles remain unchanged, the visibility graph only needs to be built once, and subsequent updates are only required. The visible edges are identified and the shortest path is recalculated, resulting in less incremental computation.

[0055] In box 302, the effective swing fulcrum is determined based on the actual path. The distance in the actual path... Recent bending point This is the effective pivot point, denoted as . If the path has no bends (the rope path is a straight line), then the effective swing fulcrum is the current connection point. It itself. Continuing with the example above, the path is... There is only one bend. The bending point is the effective swing fulcrum. The coordinates are (3, 1.5).

[0056] During the stationary operation phase, the worker's position changes slowly, and the rope path usually remains stable. The above path calculation is performed at a low frequency, such as once every 3 seconds. During the horizontal transfer phase, the worker's continuous movement causes the rope path to change rapidly. The path calculation is then switched to a high frequency, such as once per second, to promptly track the positional changes of the effective swing fulcrum.

[0057] In some embodiments, for step S5, please refer to Figure 4 , Figure 4 A flowchart illustrating the process of modifying the basic protection area according to an embodiment of this disclosure is shown. In block 401, the available rope length at the effective swing fulcrum is calculated. The effective swing fulcrum is then determined. Then, calculate the rope from the hanging point. arrive Sum of path lengths for each segment: ;in, This is the Euclidean distance between two adjacent nodes, in meters (m). This refers to the length of rope lost during intermediate detours from the hanging point to the effective swing fulcrum, expressed in meters (m). The available rope length from the effective swing fulcrum to the worker is: ;in The total length of the safety rope is expressed in meters (m). The unit is meters (m).

[0058] In frame 402, the basic protection area is adjusted based on the available rope length to obtain the effective protection area. When the effective swing fulcrum... With hanging point When they do not coincide, there is a deviation between the basic protection area and the actual protection capability. This deviation stems from two aspects: the center of oscillation has shifted from... Offset to ;from Available rope length for starting Less than the total rope length At this point, the basic protection area is adjusted to obtain the effective protection area. If the effective swing fulcrum coincides with the hanging point (i.e., the rope path is straight and there is no intermediate detour), the basic protection area is the effective protection area and no adjustment is needed.

[0059] Specifically, the correction is carried out in two steps. The first step is to adjust the coordinates of each vertex of the polygon in the basic protection area along the hanging point. The direction of translation to the effective swing fulcrum is offset by . The second step is to use the ratio of the available rope length to the total length of the safety rope as a scaling factor: ;in and The unit for all of them is meters (m). It is a dimensionless quantity with a value range of (0, 1]. The vertices of the translated polygon are then moved to the effective pivot point. distance multiplied by Perform a proportional scaling; the scaled polygon represents the effective protection area. Continuing with the previous example, The radius of the basic protection area in all directions has been reduced to about 58% of its original size.

[0060] The physical basis for correcting the deviation between the basic protection area and the actual effective protection area includes the fact that, when the safety rope is entangled, the center of swing after a fall originates from the attachment point. Move to the last bend. ,by Calculate the protection zone for the swing center, and at certain locations within that zone (especially) Back (On one side), the center of the circle when the rope is taut during the actual swing has shifted, and from... The available rope length to the workers is less than the total rope length, making the actual reachable horizontal distance less than expected. The ideal protection range calculated with the center as the radius and the total rope length as the radius is even smaller. If monitoring is still based on the basic protection area, workers may not receive warnings even when they have crossed the actual safety boundary, leading to a fall and impact with nearby structures. Therefore, the swing center is shifted to... ,According to the protection radius Proportional scaling, geometrically equivalent to recalculating the safety boundary using the actual swing center and the actual available rope length, is an accurate correction of the basic protection area under rope path detour conditions.

[0061] Optionally, further inspection can be performed after scaling. Distribution of nearby local components: and Calculate in the perpendicular direction of the connecting line The distance between the two nearest components is used to determine the scaling factor. If the distance between a component on one side is less than the radius of the scaled boundary in that direction, the boundary in that direction will be shrunk to the distance between that component and the safety margin. The location.

[0062] The above corrections only involve coordinate translation and distance multiplication operations. The execution time for a single operation is much shorter than that of a complete fall simulation pre-calculation. It can be completed with each position update. During the fixed-point operation phase, the effective swing fulcrum is stable, and the correction calculation is rarely triggered. After entering the horizontal transfer phase, the effective swing fulcrum changes with the movement of the operator, and the correction calculation is performed at the same frequency as the aforementioned steps.

[0063] In some embodiments, for step S6, the system sets the current horizontal coordinates of the operator. Compare with the polygon of the effective protection area. If the effective swing fulcrum coincides with the hanging point, then compare with the basic protection area and calculate. Shortest distance to the polygon boundary Specifically, this involves traversing each side of the polygon and calculating... The minimum distance from each point on the line segment containing each edge to the line segment is taken. Positive values ​​represent Located inside the region, a negative value indicates that the boundary has been crossed.

[0064] In this embodiment, different alarm methods are used according to the identified current operation stage; for example, during the fixed-point operation stage, the distance calculation of the effective protection area boundary is performed once every 3 seconds. Less than the warning distance It issues voice prompts to remind workers to pay attention to their activity area. The setting is based on the distance the operator needs to move from receiving a voice message to reacting. For example, the average step length while walking on a high steel beam is approximately 0.6 to 0.8 meters; taking approximately two steps as the lead time, the setting is... =1.5 meters, with a range of values, for example, from 1.0 to 2.0 meters.

[0065] During the horizontal transfer phase, the distance calculation frequency is increased to once per second. Less than A voice prompt containing the target attachment point number is issued to guide the replacement of the attachment point. The target attachment point is selected from the preset attachment point list as the closest attachment point located in front of the worker's direction of movement. When the value is less than 0, it means that the worker has crossed the boundary of the effective protection area, and the alarm is upgraded to a continuous voice alarm.

[0066] During the climbing and descent phases, the system focuses on monitoring the harness connection status and altitude, without performing distance calculations for the effective protection zone boundary. A voice alert is issued when the vertical coordinate is more than 2 meters above the starting platform and neither the main rope nor the backup belay rope is connected to the anchor point. The voice alert stops when at least one rope is connected to the anchor point.

[0067] In one embodiment, during the horizontal transfer phase, after the worker receives the reattachment guidance, the system continuously monitors the safety rope connection status. When it detects that either the main rope or the backup safety rope is connected to the new attachment point, and the worker's current position is within the basic protection area of ​​the new attachment point, the reattachment is considered successful. After a successful reattachment, the actual path calculation for the safety rope around obstacles is re-executed starting from the new attachment point, updating the basic protection area to the basic protection area of ​​the new attachment point. Subsequently, as the worker continues to move within the coverage area of ​​the new attachment point, the rope path tracking and correction process is run again based on the new attachment point. When the phase identification result switches from the horizontal transfer phase to the fixed-point operation phase, the execution frequency of distance calculation switches to a low-frequency mode.

[0068] In one embodiment, when the stage identification result switches to the horizontal transfer stage, the system automatically starts step-by-step monitoring to continuously detect the connection status of the main rope and the backup safety rope. If both the main rope and the backup safety rope are disconnected, an audio alarm is issued until at least one rope is reconnected. When the stage identification result switches to the fixed-point operation stage, step-by-step monitoring stops and restarts when the horizontal transfer stage is entered again.

[0069] Through the above processing, the system distinguishes different operation stages based on the motion characteristics of the worker's positioning trajectory. During fixed-point operation and horizontal transfer stages, it tracks the actual path of the safety rope to determine the effective swing fulcrum. Based on this, it dynamically corrects the pre-calculated basic protection area to obtain the effective protection area, and selects the corresponding monitoring frequency and alarm strategy according to the different risk characteristics of each operation stage. In densely packed structural environments, this method corrects the static analysis bias based on the hanging point as the fixed swing center, making the assessment of the protection range closer to the actual swing dynamics after a fall. Simultaneously, by identifying the stage, computational resources are concentrated on the higher-risk horizontal transfer stage, reducing unnecessary high-frequency calculations and voice interference during the fixed-point operation stage.

[0070] Please see Figure 5 , Figure 5 This is a structural block diagram of a height-climbing safety belt monitoring system based on work phase identification and spatial topology path, provided in an embodiment of this application. Figure 5As shown, the system includes: a structural space modeling module 501, used to acquire the spatial information of structural components and the coordinates of hanging points in the working layer, establish a structural space model, and extract the horizontal projection outer boundary of the components to form a two-dimensional obstacle set; a basic protection area calculation module 502, used to pre-calculate the basic protection area of ​​each hanging point, with the hanging point as the swing center, through collision detection of the falling swing trajectory and the component; a work stage identification module 503, used to extract the motion features within the time window based on the three-dimensional coordinate sequence of the workers, and identify the current work stage based on the motion features; and an actual path calculation module 504, used when the work stage is a fixed-point work stage. During the segment or horizontal transfer phase, the actual path of the safety rope around the obstacles is calculated based on the coordinates of the current connection point, the current coordinates of the operator, and the set of two-dimensional obstacles. An effective swing fulcrum is determined based on this actual path. The protection zone correction module 505 calculates the available rope length at the effective swing fulcrum based on the actual path. Using the effective swing fulcrum as a reference, the basic protection zone is corrected according to the available rope length to obtain the effective protection zone. The alarm module 506 calculates the distance from the operator's current position to the boundary of the effective protection zone, selects an alarm strategy based on the work phase, and issues a reattachment prompt when the distance is less than the warning distance.

[0071] Each processing unit and / or module in the embodiments of this application can be implemented by an analog circuit that implements the functions described in the embodiments of this application, or by software that executes the functions described in the embodiments of this application.

[0072] Based on the same inventive concept, this application also provides an electronic device, the method corresponding to which can be the method in the foregoing embodiments, and its problem-solving principle is similar to that method. For example... Figure 6 As shown, Figure 6 This is a schematic block diagram of an electronic device provided in an embodiment of the present disclosure. The device includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the methods and / or technical solutions of the foregoing embodiments of the present application.

[0073] In particular, the methods and / or embodiments in this application can be implemented as computer software programs. For example, the embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowchart. When the computer program is executed by a processor, it performs the functions defined in the methods of this application.

[0074] Another embodiment of this application provides a storage medium storing computer program instructions thereon, which can be executed by a processor to implement the methods and / or technical solutions of any one or more embodiments of this application.

[0075] In the above embodiments, the descriptions of each embodiment have different focuses. Parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments. The above descriptions are merely preferred embodiments of this application and explanations of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by specific combinations of the above technical features, but should also cover other technical solutions formed by arbitrary combinations of the above technical features or their equivalent features without departing from the inventive concept.

Claims

1. A method for monitoring safety belts at heights based on work phase identification and spatial topology path, characterized in that, include: Obtain the spatial information of structural components and the coordinates of hanging points in the working layer, establish a structural spatial model, and extract the horizontal projection outer boundary of the components to form a two-dimensional obstacle set; For each anchor point, with the anchor point as the swing center, the basic protection area of ​​each anchor point is pre-calculated by detecting the collision between the falling swing trajectory and the component; based on the three-dimensional coordinate sequence of the operator, the motion characteristics within the time window are extracted, and the current operation stage is identified based on the motion characteristics; when the operation stage is a fixed-point operation stage or a horizontal transfer stage, the actual path of the safety rope around the obstacles is calculated based on the coordinates of the current anchor point, the current coordinates of the operator, and the two-dimensional obstacle set, and the effective swing fulcrum is determined based on the actual path; The available rope length at the effective swing fulcrum is calculated based on the actual path. Using the effective swing fulcrum as a reference, the basic protection area is corrected according to the available rope length to obtain the effective protection area. The distance from the current position of the operator to the boundary of the effective protection area is calculated. An alarm strategy is selected according to the operation stage. When the distance is less than the warning distance, a replacement prompt is issued.

2. The method according to claim 1, characterized in that, Determining the effective swing fulcrum based on the actual path includes: when there is a bend in the actual path, determining the bend closest to the worker as the effective swing fulcrum; when there is no bend in the actual path, determining the current connection point as the effective swing fulcrum.

3. The method according to claim 1, characterized in that, The calculation of the actual path of the safety rope around the obstacle includes: taking the horizontal coordinates of the current connection point, the current horizontal coordinates of the worker, and the vertices of the convex hulls of each obstacle in the two-dimensional obstacle set as nodes of the visibility graph; for any two nodes, if the line connecting them does not pass through the interior region of any obstacle, then an edge is established, with the weight of the edge being the Euclidean distance between the two nodes; taking the horizontal coordinates of the current connection point as the starting point and the current horizontal coordinates of the worker as the ending point, the shortest path is found on the visibility graph to obtain the actual path.

4. The method according to claim 1, characterized in that, The motion characteristics include the rate of change of height, the rate of horizontal movement, and the stability of horizontal movement direction; the rate of change of height is the ratio of the change in vertical coordinates within a time window to the length of the time window; the rate of horizontal movement is the ratio of the cumulative displacement of adjacent coordinate points on the horizontal plane within a time window to the length of the time window; and the stability of horizontal movement direction is the standard deviation of the difference in the horizontal displacement direction angles of adjacent segments within a time window.

5. The method according to claim 4, characterized in that, The operation phases include a climbing phase, a descent phase, a horizontal transfer phase, and a stationary operation phase, determined in the following priority order: when the rate of change of altitude is greater than the climbing rate threshold, it is determined to be the climbing phase; when the rate of change of altitude is less than a negative value of the descent rate threshold, it is determined to be the descent phase; when the absolute value of the rate of change of altitude is not greater than the climbing rate threshold, and the horizontal movement rate is greater than the horizontal movement rate threshold, and the horizontal movement directional stability is less than the directional stability threshold, it is determined to be the horizontal transfer phase; if none of the above conditions are met, it is determined to be the stationary operation phase.

6. The method according to claim 1, characterized in that, The pre-calculation of the basic protection area for each anchor point includes: taking sampling points at set intervals on the horizontal plane with the anchor point as the center; for each sampling point, simulating the swing trajectory of a worker falling from that position with the anchor point as the center, and calculating the shortest distance between the worker's body envelope and the enclosure box of each structural component at each discrete position of the swing trajectory; when the shortest distance is always greater than the safety margin throughout the swing process and the total fall height does not exceed the available clearance height below the working layer, the sampling point is marked as an internal point of the basic protection area; traversing all sampling points, connecting the outer boundaries of all internal points to form a closed polygon, which is the basic protection area of ​​the anchor point.

7. The method according to claim 1, characterized in that, The step of correcting the basic protection area based on the available rope length includes: translating the coordinates of each vertex of the polygon in the basic protection area along the direction from the current connection point to the effective swing fulcrum; using the ratio of the available rope length to the total length of the safety rope as a scaling factor, scaling the distance from each vertex of the translated polygon to the effective swing fulcrum according to the scaling factor to obtain the effective protection area.

8. The method according to claim 1, characterized in that, During the fixed-point operation phase, the calculation of the actual path of the safety rope around the obstacle and the calculation of the distance from the current position of the operator to the boundary of the effective protection area are performed at a first frequency. During the horizontal transfer phase, it is executed at a second frequency higher than the first frequency.

9. The method according to claim 1, characterized in that, When the operation phase switches to the horizontal transfer phase, step-by-step monitoring is activated to detect the connection status of the main rope and the backup safety rope. When both the main rope and the backup safety rope are disconnected, an audio alarm is issued. When the operation phase switches to the fixed-point operation phase, step-by-step monitoring is stopped.

10. A height-climbing safety belt monitoring system based on work phase identification and spatial topology path, characterized in that, include: The structural space modeling module is used to obtain the spatial information of structural components and the coordinates of hanging points in the working layer, establish a structural space model, and extract the horizontal projection outer boundary of the components to form a two-dimensional obstacle set; the basic protection area calculation module is used to pre-calculate the basic protection area of ​​each hanging point with the hanging point as the swing center and through the collision detection of the falling swing trajectory and the components. The work phase identification module is used to extract motion features within a time window based on the three-dimensional coordinate sequence of the workers, and to identify the current work phase based on the motion features. The actual path calculation module is used to calculate the actual path of the safety rope around the obstacles based on the coordinates of the current connection point, the current coordinates of the operator, and the two-dimensional obstacle set when the operation stage is a fixed-point operation stage or a horizontal transfer stage, and to determine the effective swing fulcrum based on the actual path. The protective area correction module is used to calculate the available rope length at the effective swing fulcrum based on the actual path, and correct the basic protective area based on the available rope length using the effective swing fulcrum as a reference to obtain the effective protective area; the alarm module is used to calculate the distance from the current position of the operator to the boundary of the effective protective area, select an alarm strategy according to the operation stage, and issue a replacement prompt when the distance is less than the warning distance.

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