Autonomous Berthing / Unberthing Test Method and System for Unmanned Commercial Ships

Abstract

The present invention discloses a method and system for testing autonomous berthing and unberthing of an underactuated merchant ship, the method includes the steps of using a sensing module to monitor water environment data, position data of the underactuated merchant ship and status data of the underactuated merchant ship, a data processing module summarizing the monitoring data of the sensing module and performing data fusion, a scene generator constructing the state information of the water area where the underactuated merchant ship autonomously berths and unberths based on the fusion data, a ship motion simulator constructing the motion status information of the underactuated merchant ship and transmitting the relevant information data to a server database, an algorithm module planning the ship berthing and unberthing path based on the relevant information data, an evaluation module comparing the actual navigation path of the underactuated merchant ship with the planned path, if the evaluation result is successful, repeating the steps until the autonomous berthing and unberthing is completed, if the evaluation result is unsuccessful, stopping the test and eliminating the problem. The system includes a sensing module, a data processing module, an evaluation module and a display module. The present invention improves the test efficiency of the autonomous berthing and unberthing of an underactuated merchant ship and improves the safety in the test process of the underactuated merchant ship.

Description

[Technical field]

[0001] The present invention relates to a method and system for testing autonomous berthing and unberthing of underactuated merchant ships. [Background technology]

[0002] An unmanned ship refers to a ship that uses sensors, communications, the Internet of Things, the Internet and other technological means to automatically sense and obtain information and data about the ship itself, the marine environment, logistics, ports, etc., and realizes intelligent operation in ship navigation, management, maintenance, cargo transportation, etc. based on computer technology, automatic control technology and big data processing and analysis technology, making ships safer, more environmentally friendly, more economical and more reliable. Research and market demand in the field of unmanned ship marine equipment manufacturing is becoming increasingly widespread.

[0003] Berthing and unberthing is an important part of the process of conventional ships sailing on the sea, and is also one of the most complicated and difficult processes to operate. The technology of entering and leaving port is also an important technology of smart ships, and the technology of entering and leaving port of smart ships not only controls the direction and speed of the ship, but also includes many other contents such as berth stabilization, trajectory tracking, and route planning. In the process of berthing and unberthing, there are dangerous elements due to artificial uncertainty, and the working environment at sea is complex. Conventional ships do not have an evaluation and planning system of the fusion environment and its own data, making it difficult to make plans based on real-time situations, resulting in low overall controllability and low degree of intelligence. Summary of the Invention [Problem to be solved by the invention]

[0004] Objective of the invention: The objective of the present invention is to provide a method and system for evaluating the autonomous berthing and unberthing test operations of an underactuated merchant ship in real time, thereby improving the test efficiency and safety during the ship's berthing and unberthing process. [Means for solving the problem]

[0005] Technical solution: The autonomous berthing and unberthing test method for an underactuated commercial ship according to the present invention, Step S1: using a sensing module to monitor water environment data, position data of the underactuated merchant ship, and status data of the underactuated merchant ship, and transmitting the three pieces of data to a data processing module; Step S2: the data processing module consolidates the monitoring data of the sensing modules and performs data fusion; Step S3 in which the scene generator uses the fused data to construct information on the state of the water area where the underactuated merchant ship autonomously approaches or leaves the berth, and transmits the related information data to a server database; Step S4: the ship motion simulator uses the fused data to construct motion state information of the underactuated merchant ship, and transmits related information data to a server database; Step S5: the underactuated merchant ship algorithm module plans a ship approaching and leaving route based on the water area state information and the motion state information of the unmanned ship; Step S6: the evaluation module accesses the server database in real time, compares the actual navigation path of the underactuated merchant vessel with the planned path to obtain deviations, and evaluates the behavior of the actual underactuated merchant vessel based on the evaluation criteria; The method includes a step S7 in which the server controls the underactuated merchant ship based on the evaluation result, and if the evaluation result is pass, the steps are repeated until autonomous berthing / unberthing is completed, and if the evaluation result is fail, the test is stopped and the test is performed after investigating the problem.

[0006] The water area environmental data in step S1 includes the wind speed and direction, current speed and direction, temperature, humidity, and wave height and wave pressure in the water area, and the underactuated merchant ship status data includes the speed, direction, acceleration, and three-axis attitude angle of the underactuated merchant ship.

[0007] The detection method for the position data of the underactuated merchant ship is to combine the GPS positioning method, the acoustic positioning method, the visual identification positioning method and the UWB positioning method, thereby obtaining the distance between the underactuated merchant ship and the berth and other targets.

[0008] The data fusion adopts intermediate sensor fusion technology and Kalman filter, thereby obtaining accurate data after fusion; the intermediate sensor fusion technology: Step S21: setting data measured by the sensing module for the first time as an initial measurement value; A step S22 in which the filter initializes the state and covariance matrices based on initial measurements; a step S23 in which the filter receives new measurements within a preset period and gives a prediction within this period using the Bayesian algorithm; a step S24 of comparing the measured and predicted values, the filter assigning a corresponding weight to each value; A step S25 of receiving corresponding measurements within the next predetermined time period and performing an update step with the algorithm with corresponding predicted values ​​is included.

[0009] The ship docking / undocking route planning in step S5 is Step S51 of dividing the berthing process into two parts: a trajectory planning phase far from the dock and a stabilized berthing phase close to the dock; Step S52: conducting simulation studies on the above two parts and optimizing the artificial potential field method at the same time; and step S53 of plotting the trajectory plan and the steering angle output curve.

[0010] The evaluation process in step S6 is as follows: Step S61 of analyzing factors affecting berthing, calling out key points and standards for berthing, and obtaining evaluation indexes; Step S62 of classifying the indicators and constructing an evaluation indicator system; Using the analytic hierarchy process, the importance of each indicator in the unmanned ship autonomous berthing / unberthing test evaluation index system is compared, and the weight W of each indicator is calculated. i The criterion for assigning the markers' scores is determined, and the markers are scored based on the data of the markers at each test time. i,t Step S63 to obtain Each index weight W i and the score R i,t In addition, the final score S of each test index at the autonomous berthing / unberthing test monitoring time t of the underactuated merchant ship isi,t Step S64 to obtain The scores of each index are summed up to obtain the overall autonomous berthing / unberthing score S at time t. t and a step S65 of obtaining

[0011] The weight W in the analytic hierarchy process i The step of determining Step S631 of establishing a hierarchical structure describing all structural elements based on the evaluation index; Step S632 of comparing the structuring elements two by two and constructing all the decision matrices; Step S633: solving the judgment matrix to obtain feature roots and feature vectors, checking whether each judgment matrix has perfect consistency, and if it does not satisfy the consistency condition, modifying the judgment matrix until it does; and step S634 of calculating combination weights of elements of each layer and checking structure consistency.

[0012] The autonomous berthing and unberthing test system for an under-actuated merchant ship described in the present invention includes a sensing module, a data processing module, an algorithm module, an evaluation module and a display module, wherein the sensing module monitors the water environment and the status of the under-actuated merchant ship, the data processing module receives and processes the data monitored by the sensing module, the algorithm module calls up the fusion data from the data processing module in the server and performs path planning, the evaluation module calls up the real-time motion status information and path planning information of the under-actuated merchant ship in the server, and the display module calls up the server information and displays information related to the autonomous berthing and unberthing test of the under-actuated merchant ship on the display after performing graphics processing.

[0013] The data processing module further includes a scene generator, a ship motion simulator, and a data fusion module, wherein the data processing module receives data monitored by the sensing module and performs data fusion, the scene generator constructs water area state information based on the fused data, and the ship motion simulator constructs underactuated merchant ship motion information. Effect of the Invention

[0014] Beneficial Effects: The present invention has the following significant advantages over the prior art: monitoring and data processing of water environment and ship state, constructing water state information and ship motion information, and planning a route based on the information, an evaluation module compares the actual route with the planned route to obtain deviations, and automatically scores based on the determined index evaluation criteria, improving test efficiency; and adopting the analytic hierarchy process to reduce the decision weight and subjectivity of evaluation when constructing and scoring the autonomous berthing and unberthing evaluation index of the underactuated merchant ship, so as to improve the accuracy of the final result and the safety in the ship berthing process. [Brief description of the drawings]

[0015] [Figure 1] 1 is a method flow chart of the present invention. [Diagram 2] FIG. 1 is a schematic diagram of the system structure of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The technical solution of the present invention will be further described below in conjunction with FIG. 1 and FIG. 2. As shown in FIG. 1, the autonomous berthing and unberthing test method and system for an underactuated commercial ship includes: Step S1: using a sensing module to monitor water environment data, position data of the underactuated merchant vessel, and status data of the underactuated merchant vessel, and transmitting the three pieces of data to a data processing module; Step S2: the data processing module consolidates the monitoring data of the sensing modules and performs data fusion; Step S3 in which the scene generator uses the fused data to construct information on the state of the water area in which the underactuated merchant ship autonomously approaches or leaves the berth, and transmits the related information data to a server database; Step S4: the ship motion simulator uses the fused data to construct motion state information of the underactuated merchant ship, and transmits related information data to a server database; Step S5: the underactuated merchant ship algorithm module plans a ship approaching and leaving route based on the water area state information and the motion state information of the unmanned ship; Step S6, in which the evaluation module calls the server database, compares the actual navigation path of the underactuated merchant vessel with the planned path to obtain deviations, and evaluates the behavior of the actual underactuated merchant vessel based on the evaluation criteria; The method includes a step S7 in which the server controls the underactuated merchant ship based on the evaluation result, and if the evaluation result is pass, the steps are repeated until autonomous berthing / unberthing is completed, and if the evaluation result is fail, the test is stopped and the test is performed after investigating the problem.

[0017] As shown in Figure 2, the autonomous berthing and unberthing test system for an under-actuated merchant ship includes a sensing module, a data processing module, an algorithm module, an evaluation module and a display module, where the sensing module monitors the water environment and the status of the under-actuated merchant ship, the data processing module receives and processes the data monitored by the sensing module, the algorithm module calls the fusion data from the data processing module in the server and performs route planning, the evaluation module calls the real-time motion status information and route planning information of the under-actuated merchant ship in the server, and the display module calls the server information and displays information related to the autonomous berthing and unberthing test of the under-actuated merchant ship on the display after graphics processing.

[0018] In step S1, the sensing module monitors the water environment and the state (position, attitude) of the underactuated merchant ship, and transmits the data to the data processing module. In this step, the state data of the underactuated merchant ship is detected. Specifically, the position of the underactuated merchant ship is firstly located, and the positioning method is a combination of GPS positioning, acoustic positioning, visual identification positioning and UWB positioning, and by combining multiple positioning methods, the position of the underactuated merchant ship can be accurately determined in any case, and the distance between the underactuated merchant ship and the berth and other targets is obtained as the position data of the underactuated merchant ship. The attitude of the underactuated merchant ship, including the three-axis attitude angle and acceleration, is measured by the inertial measurement unit in the sensing module, and the direction and speed of the unmanned ship on the water surface are obtained as the state data of the underactuated merchant ship through coordinate system transformation. After knowing the status data of the underactuated merchant ship, the water environment is detected, and the sensing module includes a wave height meter for measuring and recording the height of waves in the water area, a wave pressure meter for measuring and recording the pressure of waves in the water area, and a wind speed and wind direction meter for measuring and recording the wind speed and wind direction in the water area, and further includes a temperature sensor for measuring and recording temperature, a humidity sensor for measuring and recording humidity, and a current speed and direction detection float, and these data are regarded as water environment data.

[0019] The data processing module compiles the monitoring data of the sensing module and performs data fusion. In this step, the data measured by the sensing module is processed by using intermediate sensor fusion technology and Kalman filtering to obtain the most accurate fusion data after fusion. In a specific implementation process, the merchant ship and covariance matrix are initialized based on the data measured by the sensing module for the first time, and within a certain period T, the Kalman filter receives new measurements of the sensor, the algorithm gives a predicted value, and the filter compares the predicted value with the actual measurement value and also gives fusion data within the period, during which the Kalman filter gives different weights to the predicted value and the measurement value according to the uncertainty of each value, and within the next T period, another measurement is received, and the algorithm gives another predicted value, thereby starting the comparison and fusion of the next data.

[0020] The scene generator uses the fused data to construct state information of the water area where the under-actuated merchant ship autonomously comes and leaves the berth, and transmits related information data to the server database, that is, the scene generator in the data processing module establishes a simulation environment of the water area where the under-actuated merchant ship comes and leaves the berth, and provides real-time fusion data to the simulation environment, and transmits the simulation environment to the server database. The ship motion simulator uses the fused data to construct motion state information of the under-actuated merchant ship, and transmits related information data to the server database, and establishes an under-actuated merchant ship model having real-time motion state information, and transmits it to the server database.

[0021] The underactuated merchant ship algorithm module plans the ship's berthing and unberthing path based on the water area posture information and the motion state information of the unmanned ship. In this step, the server performs trajectory planning for the task of the underactuated merchant ship, and the underactuated merchant ship has a decision that needs to be alerted. Therefore, the process of docking at the dock is divided into two parts: the trajectory planning stage far from the dock and the stabilized docking stage close to the dock. Simulation research is carried out for each of the two parts, and optimization is performed for the traditional artificial potential field method. In the optimization process, considering that the size of the merchant ship is large, the influence distance of the obstacle is wide, and if the gravitational force is too large, it may collide with the obstacle ship, the present invention adds a range limit to the traditional gravitational function to avoid the problem of excessive gravitational force caused by being too far from the transitional area. Since there is an obstacle near the transitional area, the repulsive force field generated is large, and the ship cannot approach the target point, the repulsive force function is optimized and the influence of the distance between the target and the ship on the repulsive force is added. When a ship approaches the transition area, the repulsive field generated by the surrounding obstacles against it will increase, but the distance between them will be shortened, so that the repulsive field can be weakened, solving the problem that the attractive force is too strong and the target cannot be reached, and then drawing the trajectory plan and the rudder angle output curve, providing a basis for selecting a suitable route for the ship's navigation before entering the berth.

[0022] The evaluation module accesses the server database in real time, compares the actual navigation path of the underactuated merchant ship with the planned path to obtain the deviation, and evaluates the behavior of the actual underactuated merchant ship based on the evaluation criteria. Specifically, the evidence theory and the analytic hierarchy process are combined to compare the importance of each indicator in the unmanned ship autonomous berthing and unberthing test evaluation index system, and the weight W of each indicator is calculated. i The criterion for assigning the markers' scores is determined, and the markers are scored based on the data of the markers at each test time. i,t The final score S of each test index at the autonomous berthing / unberthing test monitoring time t of the underactuated commercial ship is obtained by combining each index weight and the scoring score. i,t The scores of each index are added to obtain the overall autonomous approach / departure score S at time t. t The weight W is obtained by the analytic hierarchy process. i The step of determining includes the steps of establishing a hierarchical structure describing the system function or having independent features inside; comparing the structural elements two by two to construct all the judgment matrices; solving the judgment matrices to obtain the feature roots and feature vectors, checking whether each judgment matrix has perfect consistency, and if the consistency condition is not met, modifying the judgment matrix until it is met; and calculating the combination weights of the elements of each layer and checking the structural consistency.

[0023] The server controls the underactuated merchant ship based on the evaluation result, and if the evaluation result is pass, repeats the steps until autonomous berthing / unberthing is completed, and if the evaluation result is fail, stops the test and performs another test after investigating the problem.

[0024] The autonomous berthing and unberthing test system for an underactuated commercial ship suitable for the above method shown in FIG. 2 includes a sensing module, a data processing module, an algorithm module, a server, an evaluation module, and a display module. The data processing module includes a scene generator, a ship motion simulator, and a data fusion module. The sensing module monitors the water environment and the state of the underactuated commercial ship, and transmits the monitored data to the data processing module for processing. The data processing module includes a scene generator, a ship motion simulator, and a data fusion module. The data processing module receives the data monitored by the sensing module and performs data fusion. The scene generator constructs water environment information. The ship motion simulator detects the underactuated commercial ship and transmits the monitored data to the data processing module for processing. The method is characterized in that: a dynamic merchant ship motion information is constructed and related information data is transmitted to the server; an algorithm module calls up information from the data processing module of the server, performs route planning, and transmits the route planning information to the server; an evaluation module calls up real-time motion status information of the under-actuated merchant ship from the server and evaluates the route planning information; the server controls the under-actuated merchant ship based on the evaluation result; if the evaluation result is pass, the steps are repeated until the autonomous berthing and unberthing is completed; if the evaluation result is fail, the test is stopped and the test is conducted after investigating the problem; and a display module calls up the server information, performs graphics processing, and then displays information related to the autonomous berthing and unberthing test of the under-actuated merchant ship on the display.

Claims

1. 1. A method for testing an autonomous berthing and unberthing of an underactuated merchant ship, comprising: Step S1: using a sensing module to monitor water environment data, position data of the underactuated merchant vessel, and status data of the underactuated merchant vessel, and transmitting the three pieces of data to a data processing module; Step S2: the data processing module consolidates the monitoring data of the sensing modules and performs data fusion; Step S3 in which the scene generator uses the fused data to construct state information of the water area where the underactuated merchant ship autonomously approaches or leaves the berth, and transmits related information data to a server database; Step S4: the ship motion simulator uses the fused data to construct motion state information of the underactuated merchant ship, and transmits related information data to the server database; Step S5: the underactuated merchant ship algorithm module plans a ship approaching and leaving route based on the water area state information and the motion state information of the unmanned ship; Step S6: the evaluation module calls the server database, compares the actual navigation path of the underactuated merchant vessel with the planned path to obtain deviations, and evaluates the behavior of the actual underactuated merchant vessel based on the evaluation criteria; A method for testing autonomous berthing and unberthing of an underactuated merchant ship, comprising: a step S7 in which a server controls the underactuated merchant ship based on the evaluation result; if the evaluation result is pass, the steps are repeated until the autonomous berthing and unberthing is completed; if the evaluation result is fail, the test is stopped and the test is performed after investigating the problem.

2. The autonomous docking and undocking test method for an underactuated merchant ship as described in claim 1, characterized in that the water area environmental data in step S1 includes wind speed and direction, current speed and direction, temperature, humidity, and wave height and wave pressure in the water area, and the status data of the underactuated merchant ship includes the speed, direction, acceleration, and three-axis attitude angle of the underactuated merchant ship.

3. The autonomous docking and undocking test method for an underactuated merchant ship as described in claim 1, characterized in that in step S1, the detection method for the position data of the underactuated merchant ship is to combine a GPS positioning method, an acoustic positioning method, a visual identification positioning method and a UWB positioning method to obtain the distance between the underactuated merchant ship and the berth and obstacles.

4. In step S2, the data fusion uses an intermediate sensor fusion technique-Kalman filtering to obtain accurate data after fusion, and the intermediate sensor fusion technique includes: Step S21: setting data measured by the sensing module for the first time as an initial measurement value; A step S22 in which the filter initializes the state and covariance matrix based on initial measurements; a step S23 in which the filter receives new measurements within a preset period and the algorithm gives a prediction within this period; a step S24 of comparing the measured and predicted values, the filter giving each value a corresponding weight; 2. The method for testing autonomous berthing and unberthing of an underactuated merchant ship as claimed in claim 1, further comprising a step S25 of receiving corresponding measured values ​​within a next predetermined time period and performing an update step with the corresponding predicted values ​​in the algorithm.

5. The ship docking / undocking route planning in step S5 is Step S51 of dividing the berthing process into two parts: a trajectory planning phase far from the dock and a stabilized berthing phase close to the dock; Step S52: conducting simulation studies on the above two parts and optimizing the artificial potential field method at the same time; The method for testing autonomous docking and undocking of an underactuated merchant ship as claimed in claim 1, further comprising a step S53 of plotting a trajectory plan and a rudder angle output curve.

6. The evaluation process in step S6 is as follows: Step S61: Analyzing factors affecting docking, retrieving key points and standards for docking, and obtaining evaluation indexes; Step S62 of classifying the indices and constructing an evaluation index system; Using the analytic hierarchy process, the importance of each indicator in the unmanned ship autonomous berthing / unberthing test evaluation index system is compared, and the weight W of each indicator is calculated. ｉ The index scoring level criteria are determined, and the scores are calculated based on the index data at each test time. ｉ，ｔ Step S63 to obtain Each index weight W ｉ and the score R ｉ，ｔ In addition, the final score S of each test index at the autonomous berthing / unberthing test monitoring time t of the underactuated merchant ship is ｉ，ｔ Step S64 to obtain The scores of each index are summed up to obtain the overall autonomous docking / undocking score S at time t. ｔ The method for testing autonomous docking and undocking of an underactuated merchant ship according to claim 1, further comprising the step of:

7. In step S63, the weights W are calculated by combining the evidence theory and the analytic hierarchy process. ｉ The step of determining A step S631 of establishing a hierarchical structure describing all structural elements based on the evaluation index; Step S632 of comparing the structuring elements two by two and constructing all the decision matrices; Step S633: solving the judgment matrix to obtain feature roots and feature vectors, checking whether each judgment matrix has perfect consistency, and if the consistency condition is not satisfied, modifying the judgment matrix until it is satisfied; The autonomous docking and undocking test method for an underactuated merchant ship as claimed in claim 6, further comprising: a step S634 of calculating combination weights of elements of each layer and checking structural consistency.

8. 2. The autonomous berthing and unberthing test system for an under-actuated merchant vessel using the method according to claim 1, comprising: a sensing module, a data processing module, an algorithm module, an evaluation module and a display module, wherein the sensing module monitors the water environment and the status of the under-actuated merchant vessel; the data processing module receives and processes the data monitored by the sensing module; the algorithm module calls up the fusion data from the data processing module in the server and performs route planning; the evaluation module calls up the real-time motion status information and route planning information of the under-actuated merchant vessel in the server; and the display module calls up the server information and displays information related to the autonomous berthing and unberthing test of the under-actuated merchant vessel on the display after performing graphics processing.

9. The autonomous berthing and unberthing test system for an underactuated merchant ship as described in claim 8, characterized in that the data processing module further includes a scene generator, a ship motion simulator and a data fusion module, the data processing module receives data monitored by the sensing module, the data fusion module performs data fusion, the scene generator constructs water area situation information based on the fused data, and the ship motion simulator constructs underactuated merchant ship motion information.

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