A ship-bridge collision hazard analysis method based on real-time risk assessment

Abstract

The present invention discloses a method for analyzing hidden dangers of ship-bridge collision based on real-time risk assessment, including: obtaining basic parameters of the bridge and the basic parameters of the waterway; demarcating the supervision range of the bridge area; demarcating the threshold evaluation level according to the collision risk tolerance of the bridge; starting the supervision and analysis mechanism for ships entering the supervision range; using sensing equipment to collect real-time position information; according to the ship position parameters at time t-1 and time t, substituting them into the real-time risk assessment model, analyzing the probability of i ships in the bridge area colliding with each bridge pier at time t; calculating the collision risk of the waterway pier at time t based on the collision risk probability of all ships in the supervision area at the current time; and judging whether the ship passes through the bridge. The present invention can determine the collision risk of a moving ship relative to the bridge in real time, and can also determine the real-time collision risk of the bridge pier under the current traffic flow, thereby discovering the hidden dangers of ship collision with the bridge in advance.

Description

Technical Field

[0001] The present invention relates to bridge safety early warning technology, and in particular to a ship-bridge collision hidden danger analysis method based on real-time risk assessment. Background Art

[0002] At present, the capsizing of ships will lead to the leakage of pollutants on board, causing serious consequences such as river and water pollution and ecological environment damage.

[0003] To this end, most bridges use anti-collision devices to improve this situation. However, physical anti-collision can indeed reduce collision damage and reduce the consequences of accidents, but it cannot reduce the frequency of ship collisions with bridges. After the accident, there are still complex problems such as emergency response, rescue, and maintenance. Therefore, the industry has gradually adopted the installation of active anti-collision warning systems for bridges to reduce the frequency of accidents and solve such problems from the root. Generally, the following methods are adopted: First, radar and AIS ship information collectors are used as reading devices for ship positions, and the relative position relationship between the ship and the bridge is used to determine whether there is a collision hazard. This method is simple and direct, but there is a feedback lag and insufficient reserved correction time, which cannot completely prevent accidents. The second method is to introduce a certain evaluation mechanism and combine it with the classic probability model to evaluate the ship risk factor. However, the model is relatively simple, the parameters are insufficient, and the real-time performance is poor, making it difficult to achieve the purpose of accurate prediction. Summary of the Invention

[0004] The main purpose of the present invention is to provide a ship-bridge collision hazard analysis method based on real-time risk assessment, which can determine the collision risk of a moving ship relative to a bridge in real time, and can also determine the real-time collision risk of a bridge pier under the current traffic flow, so as to discover the hidden dangers of ship collision with bridge in advance and achieve better prediction and early warning effects. It is suitable for inland waterway bridges, cross-sea bridges, etc. The application of this method can judge ships with abnormal tracks in advance, effectively avoid ship-bridge collision accidents, and escort safe shipping.

[0005] The technical solution adopted by the present invention is: a method for analyzing ship-bridge collision hazards based on real-time risk assessment, comprising:

[0006] Step 1: Obtain basic parameters of bridge and waterway;

[0007] Step 2: Delineation of the supervision scope of the bridge area;

[0008] Step 3: Determine the threshold assessment level based on the bridge's impact risk tolerance;

[0009] Step 4: Start the supervision and analysis mechanism for ships entering the supervision area;

[0010] Step 5: Use sensing equipment to collect real-time location information; draw the ship's track data based on historical data, and make a preliminary determination of the relative position of the ship and the bridge pier;

[0011] Step 6: Based on the ship position parameters at time t-1 and time t, substitute them into the real-time risk assessment model to analyze the probability P of a ship i in the bridge area hitting each bridge pier at time t. Si ;

[0012] Step 7: Calculate the collision risk P of the channel bridge pier at time t based on the collision risk probability of all ships in the supervision area at the current time B ;

[0013] Step 8: Compare the impact risk probability calculated in Steps 5 and 6 with the bridge's own threshold. If the comparison result exceeds the set risk threshold, determine the risk level based on the threshold, activate the graded warning mechanism, and take corresponding emergency measures. If the comparison result is less than the risk threshold, continue monitoring and proceed to Step 4.

[0014] Step 9: Based on the real-time collected ship position information, determine whether the ship has passed the bridge. If the ship has passed the bridge, the analysis ends; otherwise, the tracking calculation is repeated until the ship has safely passed the bridge.

[0015] Furthermore, the bridge parameters and waterway parameters in step 1 include: the position of the main pier of the bridge, the structural dimensions of the main pier, the bridge span, the waterway width, the waterway centerline, the water flow velocity, the water flow direction, the ship type, the ship size, and the ship crossing the bridge speed.

[0016] Furthermore, the scope of supervision in step 2 should be defined based on the waterway grade, water characteristics, and by soliciting opinions from maritime waterway and other regulatory authorities.

[0017] Furthermore, the bridge collision risk threshold of the entire bridge area water area in step 3 is divided into three levels: A, B, and C according to the risk level, representing three risk levels of low collision risk, average collision risk, and extremely high collision risk, respectively.

[0018] Furthermore, in step 5, the ship's information perception equipment includes but is not limited to radar, AIS information receiver, and image acquisition method.

[0019] Furthermore, in step 6, the ship collision probability refers to the probability of a ship colliding with a bridge at a certain moment, at a certain position and at a certain speed after entering the bridge area;

[0020] The real-time risk assessment model is a real-time path integral algorithm optimized based on the Kunzi model. Its core calculation formula is:

[0021]

[0022] Where s is the stopping distance, μ s , σ s are the mean and standard deviation of the stopping distance s; their determination should be evaluated and selected in combination with the types and tonnage of local navigable ships, the water level at that time, and the ship speed dynamics;

[0023] D is the distance from the ship to the bridge axis:

[0024] k ba and b ba are the slope and intercept of the x-axis and the bridge axis;

[0025] f(s) is the probability that the ship can stop at a distance of s meters from the bridge; f(θ) is the probability that the ship at the current position can be effectively controlled after mistaking the ship for an angle θ;

[0026]

[0027] s(θ)=Dsinθ bc / sin(θ bc -θ)

[0028]

[0029] θ min ,θ max They represent the lower and upper bounds of the yaw angle of a ship of a certain tonnage hitting a bridge pier at point (x, y) in the channel, and are determined by the following formula:

[0030] (1) When y<Y0-BP2-BM2:

[0031]

[0032]

[0033] (2) When Y0-BP / 2-BM / 2<y<Y0+BP / 2+ / BM / 2:

[0034]

[0035]

[0036] (3) When y>Y0+BP / 2+ / BM / 2:

[0037]

[0038]

[0039] Where A(x, y) is the coordinate of the ship's track point; (X0, Y0) is the coordinate of the center of the target pier; BP and BH are the width and length of the pier, respectively; BM and BL are the beam and length of the ship, respectively.

[0040] Furthermore, in step 7, the probability of a bridge pier being hit refers to the sum of the probabilities of all ships entering the bridge area hitting the underwater bridge pier at a certain moment, and the calculation formula is:

[0041]

[0042] Where: P B is the probability of a bridge being hit, n is the number of ships in the bridge area at a certain moment, P Si is the probability of the i-th ship hitting the bridge.

[0043] Advantages of the present invention:

[0044] The present invention proposes a risk probability calculation model for ships and piers, establishes a real-time assessment mechanism from the dual perspectives of ships and bridges, and more accurately locates ship risks and pier risks, making early warnings more inclined and easier to locate the root causes of hidden dangers.

[0045] Based on the size of the probabilistic risk, the idea of ​​risk grading was proposed, and a threshold evaluation mechanism for impact risk was established to implement the early warning process more effectively and accurately and make full use of emergency resources.

[0046] The influence of water level change frequency and ship speed on collision probability is taken into account, and these two dynamic influencing factors are added to the analysis and calculation to make the calculation method more in line with actual conditions.

[0047] Unnecessary parameters were optimized, and a fast, real-time integral-based, dynamically refreshed risk probability analysis method was proposed, which has good real-time performance and stronger practicality.

[0048] The present invention takes into account two factors: the real-time collision risk probability of a ship and the real-time collision risk probability of a bridge pier, thereby doubly ensuring bridge safety.

[0049] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0051] Figure 1 It is an analysis flow chart of the present invention;

[0052] Figure 2 It is a schematic diagram of the scope of the waterway in the present invention;

[0053] Figure 3 It is a schematic diagram of the risk probability model calculation implemented in the present invention. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0055] like Figure 1 As shown in FIG, the bridge collision hazard early warning method based on risk assessment includes the following steps:

[0056] Step 1: Obtaining basic parameters of bridges and waterways. Through bridge area surveys, mainly collect parameters such as pier location, pier structure dimensions, bridge span, waterway width, waterway centerline, water flow velocity, water flow direction, ship type, ship size, and ship crossing speed.

[0057] Step 2: Delineation of the supervision scope of the bridge area: The scope of the bridge area is as shown in the attached Figure 2 As shown, it includes the channel river bank line, channel edge line, and ship monitoring line. The range shown divides the bridge area water area into a restricted area and a navigable area. The algorithm model mentioned in the present invention is only for ships traveling in the navigable area. For ships in the restricted area, it is a dangerous driving behavior and there is no need to analyze the risk probability. Warning information should be issued directly.

[0058] The distance between the ship monitoring line and the bridge axis is determined based on a comprehensive assessment of the waterway grade, representative navigable ships, and the opinions of management departments and experts. It is generally not less than 1.5 km.

[0059] Step 3: Determine the threshold assessment level based on the bridge's impact risk tolerance;

[0060] Specifically, based on the bridge grade and importance, an acceptable risk threshold is set for the bridge. Generally, when there is no requirement, the risk can be set as less than 30% for low collision risk, 30%-60% for average collision risk, 60%-80% for high collision risk, and more than 80% for extremely high risk of bridge collision, which are defined as A, B, and C levels. Different emergency response plans are set accordingly to achieve the purpose of accurate early warning.

[0061] Step 4: Start the supervision and analysis mechanism for ships entering the supervision area;

[0062] In order to save resources and provide efficient early warning, the risk probability analysis mechanism is only activated for ships entering the ship monitoring line. Ships outside the monitoring line are not within the control range because they are far away from the bridge area.

[0063] Step 5: Use sensing equipment to collect real-time location information. Draw the ship's track data based on historical data and make a preliminary determination of the relative position of the ship and the bridge pier.

[0064] Specifically, sensing equipment, including lidar, microwave radar, AIS, and imaging equipment, acquires the vessel's real-time position coordinates (x, y) through direct or indirect measurement. Generally, the x direction is defined as along the bridge, and the y direction is defined as across the bridge. To ensure timely analysis, the sampling frequency is at least 5 seconds.

[0065] Step 6: Based on the ship position parameters at time t-1 and time t, substitute them into the real-time risk assessment model to analyze the probability P of a ship i in the bridge area hitting each bridge pier at time t. Si ;

[0066] Specifically, when the sensing device collects the position and speed information of the ship at time t-1 (x t-1 ,y t-1 ,v t-1 ) and the position and velocity information (x t ,y t ,v t ), and read the real-time water level parameter h from other equipment on site to determine μ s , σ s At the same time, the slope and intercept k of the ship's x-axis and the bridge axis should be calculated. ba and b ba .

[0067] Implement the following real-time integration code analysis based on JAVA or C:

[0068]

[0069] Where s is the stopping distance, μ s , σ s are the mean and standard deviation of the stopping distance s; their determination should be evaluated and selected in combination with the types and tonnage of local navigable ships, the water level at that time, and the ship speed dynamics.

[0070] D is the distance from the ship to the bridge axis:

[0071] f(s) is the probability that the ship can stop at a distance of s meters from the bridge; f(θ) is the probability that the ship at the current position can be effectively controlled after mistaking the ship for an angle θ.

[0072]

[0073] s(θ)=Dsinθ bc / sin(θ bc -θ)

[0074]

[0075] θ min ,θ max They represent the lower and upper limits of the yaw angle of a ship of a certain tonnage hitting the bridge pier at point (x, y) in the channel, respectively. Figure 3 , determined by the following formula:

[0076] (1) When y<Y0-BP / 2-BM / 2:

[0077]

[0078]

[0079] (2) When Y0-BP / 2-BM / 2<y<Y0+BP / 2+ / BM / 2:

[0080]

[0081]

[0082] (3) When y>Y0+BP / 2+ / BM / 2:

[0083]

[0084]

[0085] Where A(x, y) is the coordinate of the ship's track point; (X0, Y0) is the coordinate of the center of the target pier; BP and BH are the width and length of the pier, respectively; BM and BL are the beam and length of the ship, respectively.

[0086] Step 7: Calculate the collision risk P of the channel bridge pier at time t based on the collision risk probability of all ships in the supervision area at the current time B ;

[0087] Specifically, the real-time collision probability of all ships within the bridge area supervision range is calculated using the method in step 6, and the collision probability of each bridge pier is obtained using the following formula:

[0088]

[0089] Where: P B is the probability of a bridge being hit, n is the number of ships in the bridge area at a certain moment, PSi is the probability of the i-th ship hitting the bridge.

[0090] Step 8: Compare the impact risk probability calculated in Steps 5 and 6 with the bridge's own threshold. If the comparison result exceeds the set risk threshold, determine the risk level based on the threshold, activate the graded warning mechanism, and take corresponding emergency measures. If the comparison result is less than the risk threshold, continue monitoring and proceed to Step 4.

[0091] According to the threshold determined in step 3, it is compared with the calculated thresholds in steps 6 and 7 to determine the interval to which the risk probability belongs under the current state, and a warning alarm action is performed according to the corresponding design rules.

[0092] Step 9: Based on the real-time collected ship position information, determine whether the ship has passed the bridge. If the ship has passed the bridge, the analysis ends; otherwise, the tracking calculation is repeated until the ship has safely passed the bridge.

[0093] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for analyzing ship-bridge collision hazards based on real-time risk assessment, characterized in that: include: Step 1: Obtain basic parameters of bridge and waterway; Step 2: Delineation of the supervision scope of the bridge area; Step 3: Determine the threshold assessment level based on the bridge's impact risk tolerance; Step 4: Start the supervision and analysis mechanism for ships entering the supervision area; Step 5: Use sensing equipment to collect real-time location information; plot the ship's track data based on historical data, and make a preliminary determination of the relative position of the ship and the bridge pier; Step 6: Based on the ship position parameters at time t-1 and time t, substitute them into the real-time risk assessment model to analyze the probability P of a ship i in the bridge area hitting each bridge pier at time t. Si ; Step 7: Calculate the collision risk P of the channel bridge pier at the current moment based on the collision risk probability of all ships in the supervision area at the current moment B ; Step 8: Compare the impact risk probability calculated in Steps 6 and 7 with the bridge's own threshold. If the comparison result exceeds the set risk threshold, the risk level is determined based on the threshold, the graded warning mechanism is activated, and corresponding emergency measures are taken; If the comparison result is less than the risk threshold, continue monitoring and go to step 4; Step 9: Based on the real-time collected ship position information, determine whether the ship has passed the bridge. If the ship has passed the bridge, the analysis ends; otherwise, the tracking calculation is repeated until the ship safely passes the bridge. The ship collision probability refers to the probability of a ship colliding with a bridge at a certain moment, given its position and speed after entering the bridge area. The real-time risk assessment model is a real-time path integral algorithm optimized based on the Kunzi model. Its core calculation formula is: Where s is the stopping distance, μ s , σ s are the mean and standard deviation of the stopping distance s; the two are determined by evaluating and selecting based on the type and tonnage of local navigable ships, the water level at that time, and the ship speed dynamics; D is the distance from the ship to the bridge axis: k ba and b ba are the slope and intercept of the x-axis and the bridge axis; f(s) is the probability that the ship can stop at a distance of s meters from the bridge; f(θ) is the probability that the ship at the current position can be effectively controlled after mistaking the ship for an angle θ; s(θ)=Dsinθ bc / sin(θ bc -i) θ min ,θ max They represent the lower and upper bounds of the yaw angle of a ship of a certain tonnage hitting a bridge pier at point (x, y) in the channel, and are determined by the following formula: (1) When y<Y0-BP / 2-BM / 2: (2) When Y0-BP / 2-BM / 2<y<Y0+BP / 2+ / BM / 2: (3) When y>Y0+BP / 2+ / BM / 2: Where A(x, y) is the coordinate of the ship's track point; (X0, Y0) is the coordinate of the center of the target pier; BP and BH are the width and length of the pier, respectively; BM and BL are the beam and length of the ship, respectively.

2. The ship-bridge collision hazard analysis method based on real-time risk assessment according to claim 1 is characterized in that: The bridge parameters and waterway parameters in step 1 include: the location of the main pier of the bridge, the structural dimensions of the main pier, the bridge span, the width of the waterway, the centerline of the waterway, the water flow velocity, the water flow direction, the ship type, the ship size, and the ship's speed when crossing the bridge.

3. The ship-bridge collision hazard analysis method based on real-time risk assessment according to claim 1 is characterized in that: The scope of supervision in step 2 should be defined based on the waterway grade and water characteristics, with the opinions of the maritime waterway regulatory authorities sought.

4. The ship-bridge collision hazard analysis method based on real-time risk assessment according to claim 1 is characterized in that: The bridge collision risk threshold of the entire bridge area water area in step 3 is divided into three levels: A, B, and C according to the risk level, representing three risk levels: low collision risk, average collision risk, and extremely high collision risk, respectively.

5. The ship-bridge collision hazard analysis method based on real-time risk assessment according to claim 1 is characterized in that: Said step 5, the ship's information sensing equipment includes but is not limited to radar, AIS information receiver, and image acquisition method.

6. The ship-bridge collision hazard analysis method based on real-time risk assessment according to claim 1 is characterized in that: In step 7, the probability of a bridge pier being hit refers to the sum of the probabilities of all ships entering the bridge area hitting the underwater bridge pier at a certain moment, and the calculation formula is: Where: P B is the probability of a bridge being hit, n is the number of ships in the bridge area at a certain moment, P Si is the probability of the i-th ship hitting the bridge.

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