Electric arc additive manufacturing safety prevention and control system and method for large ship structural parts

Abstract

The invention discloses a safety prevention and control system and method for electric arc additive manufacturing of a large ship structural part. The system comprises a virtual contact wall system, a human body dynamic distance sensing system, a virtual protection space system and an operation safety protection system. According to the man-machine safety prevention and control system for the electric arc additive manufacturing system, the hierarchical and multi-mechanism man-machine safety prevention and control system is provided, real-time monitoring and safety prevention and control of human body and robot states during moving and welding operation of a gantry type welding robot are achieved, and the safety of production elements of ship structural parts is guaranteed; the safety of the human-in-the-loop welding robot system is improved through the depth camera, the distance sensor and the like, risk factors influencing production are monitored, and the safety accident rate is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to a safety control system and method for arc additive manufacturing of large ship structural parts. Background Art

[0002] Compared with traditional manufacturing methods, additive manufacturing methods can significantly improve material utilization, shorten product development cycles, etc., and achieve almost any complex geometric shape by stacking layers, breaking through the process limitations of traditional milling, casting, etc., and to a certain extent improving the design freedom of ship, aviation, and aerospace products. At the same time, mobile distributed manufacturing methods significantly improve the size, shape, and performance of manufactured structural parts, greatly improving product performance. Typical ship structural parts have the characteristics of large scale, complex topological structure, and high mechanical performance requirements. Traditional manufacturing methods such as casting and forging are prone to internal defects when manufacturing typical structural parts, and the tool is difficult to reach and the qualified rate is low. Therefore, gantry-based or mobile additive manufacturing systems are widely used in the manufacture of complex large-size parts such as ships, aviation, and aerospace. Unlike traditional industrial robot manufacturing units, additive manufacturing systems require operators to work collaboratively in the working area during the operation process, that is, human-in-the-loop additive manufacturing flexible manufacturing units. Unlike industrial robots working in closed structural environments, additive manufacturing systems can collaborate with people in specific areas to achieve manufacturing mode changes in discrete manufacturing industries. Therefore, the safety of operators or non-operators during the operation process is an issue that must be considered in the design of the additive manufacturing system. A safety control system is needed to ensure that the robot will not cause harm to personnel, equipment and the environment during operation. For example, protective fences and arc-proof plates are necessary protective devices for additive manufacturing systems. In terms of safety control during the operation of operators, patents CN111546331B and CN 118009874A disclose a human-machine collaborative robot safety protection system-level safety protection method and a human operator behavior safety detection system and method for industrial robots. The distance between the robot and the operator is measured by an optical motion capture camera, and the robot's movement speed and obstacle avoidance are determined based on the distance. Patent CN110561432A discloses a safety collaboration method and device based on human-machine integration. Based on the dynamic equivalent distance between humans and machines and the sub-operation space areas of different safety levels dynamically planned for the robot's operating space, the risk of human-machine collaboration collision is predicted, and corresponding control instructions are formulated to safely control the robot. Patents CN110978064B and CN114952854B calculate the distance between the robot end and the operator based on sensors such as depth cameras and monocular cameras, determine the current safety status of the human body through distance and running speed, make the next work plan according to different safety status, effectively avoid dangerous situations, and make human-machine collaboration safer and more efficient. The above invention patents are all based on the distance between the robot end and various parts of the human body detected by sensors to determine the safety status of the human body and formulate prevention and control plans, which to a certain extent ignores the risks of the robot body (connecting rods, joints) in the process of human-machine collaboration. In addition, a single safety prevention and control method will be affected by line of sight obstruction, signal transmission, etc., and there are risk factors. The lack of a single safety prevention and control plan will lead to major safety accidents.At the same time, external mobile devices and manufacturing objects also pose security risks, and safety prevention and control measures or methods are urgently needed to protect the safety of operators. Summary of the invention

[0003] In view of the above problems, the purpose of the present invention is to provide a safety control system and method for arc additive manufacturing of large-scale ship structural parts, so as to enable operators to operate safely during the additive manufacturing process of large-scale complex structural parts.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A safety control system for arc additive manufacturing of large ship structural parts, the system includes a virtual contact wall system, a human body dynamic distance perception system, a virtual protection space system, an operation safety protection system, and a terminal;

[0006] The virtual contact wall system is composed of a number of distance sensors evenly distributed on the workpiece base, which are connected to the workpiece base by screws and can measure the distance between the operator and the workpiece base;

[0007] The human body dynamic distance perception system is composed of a depth camera and a mounting plate. The depth camera is fixed on the gantry Z-axis arm through the mounting plate. The human body dynamic distance perception system can obtain the operator's motion information and calculate the distance between the operator and the welding robot.

[0008] The virtual protection space system is established through the kinematic model of the welding robot, and the virtual protection space is defined through the working space of the welding robot;

[0009] The operation safety protection system is composed of several protective fences, arc protection plates, dust collectors, and safety gratings. The arc protection plates and safety gratings are installed on the protective fences, and the protective fences are arranged around the arc additive manufacturing equipment; the dust collector is arranged around the workpiece base to collect the smoke and dust generated during the arc additive process;

[0010] The terminal is used to receive information from the virtual contact wall system, the human body dynamic distance perception system, the virtual protection space system, and the operation safety protection system, store, process, and display computer programs, and realize safety control of arc additive manufacturing;

[0011] Furthermore, the virtual contact wall system has an operator position and distance monitoring function, and the position and distance monitoring function can calculate the origin of the work base platform coordinate system O Base and the origin O of the operator's coordinate system Human The straight-line distance between The calculation process is as follows:

[0012]

[0013] in Represents the operator coordinate system O Human _xyz relative to the workpiece base coordinate system O Base _xyz movement transformation;

[0014] The position and distance monitoring function can calculate the origin of the gantry Z-axis arm coordinate system O Zaxis and the origin of the operator's coordinate system O Human The projection distance of the straight-line distance between The calculation process is as follows:

[0015]

[0016] in Represents the operator coordinate system O Human _xyz relative to the gantry Z-axis arm coordinate system O Zaxis _Homogeneous transformation of xyz, Indicates the rotation transformation of the operator coordinate system relative to the gantry Z-axis arm coordinate system, Indicates the movement transformation of the operator coordinate system relative to the gantry Z-axis arm coordinate system;

[0017] Furthermore, when the virtual contact wall system monitors the position and When it is greater than or equal to R+1m, the virtual protection space system will not start; when the position monitored by the virtual contact wall system and When it is between R+1m and R, the virtual protection space system is initialized; when the position monitored by the virtual contact wall system is and When it is less than or equal to R, the virtual protection space system starts working; R represents the working radius of the welding robot;

[0018] Furthermore, the kinematic model of the welding robot in the virtual protection space system is expressed as follows:

[0019]

[0020] Wherein n represents the degree of freedom of the welding robot; the boundary of the virtual protection space is a curved surface (301) formed by the farthest distance of the end points of the welding robot, and when the operator enters the virtual protection space, the human body dynamic distance perception system is activated;

[0021] Furthermore, the human body dynamic distance perception system establishes a motion model of the operator through the depth camera, and obtains the coordinates of each part of the operator in the depth camera coordinate system. Camera _xyz position, the minimum distance calculation steps between the operator and the welding robot are as follows:

[0022] Step 1: Complete the hand-eye calibration of the depth camera and the welding robot, and calculate the depth camera coordinate system O Camera _xyz and welding robot coordinate system O Robot _Homogeneous transformation relationship of xyz

[0023] Step 2: Calculate the coordinates of each moving joint of the welding robot in the welding robot coordinate system O Robot _xyz pose matrix i represents the i-th joint of the robot, and the mathematical expression is

[0024] Step 3: Calculate the coordinates of each part of the operator in the depth camera coordinate system O Camera The pose matrix j represents the jth joint of the operator;

[0025] Step 4: Calculate the distance between each part of the operator and each joint of the welding robot. The mathematical expression is:

[0026]

[0027] Step 5: Calculate the minimum distance between the operator and the welding robot. The mathematical expression is as follows:

[0028]

[0029] Where m represents the number of operator parts;

[0030] Furthermore, when the minimum distance monitored by the human body dynamic distance sensing system When the distance is greater than or equal to 1m, the welding robot's operating speed is reduced to 1m / s; when the minimum distance monitored by the human body dynamic distance sensing system is When the distance is between 0.5m and 1m, the welding robot's operating speed is reduced to 0.5m / s; when the minimum distance monitored by the human body dynamic distance sensing system is When the distance is less than or equal to 0.5m, the operating speed of the welding robot is reduced to 0.1m / s;

[0031] Furthermore, the terminal includes a memory, an input unit, a display unit, a processor and an output unit; the memory is used to store computer programs; the input unit is used to receive various instructions or parameters of a virtual contact wall system, a human dynamic distance perception system, a virtual protective space system, and an operation safety protection system; the display unit is used to display various output information of the terminal; the processor executes the computer program to enable the terminal to achieve safety control of arc additive manufacturing of large ship structures; the output unit is used to output various control instructions to control the movement of the welding robot.

[0032] A safety control method for arc additive manufacturing of large ship structural parts, comprising:

[0033] Working mechanism 1: The operation safety protection system can prevent non-staff from entering the working area and realize arc protection. When the additive manufacturing system is operating, if non-operating personnel enter the working area, the safety grating will alarm through the terminal.

[0034] Working mechanism 2: When the additive manufacturing system is operating, the virtual contact wall system is activated to monitor the operator's position in real time and calculate the distance between the operator and the workpiece base and the gantry Z-axis arm. When the distance is detected to be less than the set value, the virtual protective space system is activated;

[0035] Working mechanism 3: When the virtual protection space system is activated and the operator enters the virtual protection space, the human body dynamic distance perception system is activated;

[0036] Working Mechanism 4: The human body dynamic distance perception system achieves active safety prevention and control by monitoring the minimum distance between each part of the operator and each joint of the welding robot.

[0037] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0038] (1) The arc additive manufacturing safety control system for large ship structural parts provided by the present invention realizes hierarchical and multi-mechanism safety control by combining multiple sensors and intelligent algorithms;

[0039] (2) The hierarchical and multi-mechanism safety control solution provided by the present invention overcomes the risk hazards of a single safety control solution and improves the operating safety of operators;

[0040] (3) The safety control scheme provided by the present invention realizes real-time monitoring and safety control of the human body and robot status when the gantry welding robot is moving and welding, ensures the safety of production factors of ship structural parts, and provides reference and basis for the design of arc additive manufacturing system. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 Schematic diagram of a safety control system for arc additive manufacturing of large ship structural parts provided in Example 1 of the present invention;

[0043] Figure 2 Schematic diagram of the working mechanism of the arc additive manufacturing safety control system for large ship structural parts provided by Example 2 of the present invention;

[0044] Figure 3 A schematic diagram of the working mechanism of the virtual contact wall system provided in Example 2 of the present invention;

[0045] Figure 4 A schematic diagram of the position and distance monitoring function of the virtual contact wall system provided in Example 2 of the present invention;

[0046] Figure 5 A schematic diagram of a human motion model provided in Example 2 of the present invention;

[0047] Figure 6 A flowchart of a human body dynamic distance sensing system provided in Example 2 of the present invention;

[0048] Figure 7 This is a schematic diagram of the structure of a terminal provided in Embodiment 3 of the present invention.

[0049] In the figure: 1 is a virtual contact wall system, 101 is a distance sensor, 2 is a human body dynamic distance perception system, 201 is a depth camera, 202 is a mounting plate, 3 is a virtual protection space system, 301 is a curved surface, 4 is an operation safety protection system, 401 is a protection fence, 402 is an arc protection plate, 403 is a dust collector, 404 is a safety grating, 5 is a terminal, 501 is a memory, 502 is an input unit, 503 is a display unit, 504 is a processor and 505 is an output unit, 6 is a workpiece base, 7 is an operator, 701 is a head, 702 is a neck, 703 is a shoulder, 704 is a chest, 705 is an upper arm, 706 is an abdomen, 707 is a lower arm, 708 is a hand, 709 is a thigh, 710 is a lower leg, 711 is a foot, 8 is a gantry Z-axis arm, and 9 is a welding robot. DETAILED DESCRIPTION

[0050] In order to facilitate the understanding of the present invention, a more comprehensive description of a safety control system for arc additive manufacturing of large ship structures will be given below with reference to the relevant drawings. The accompanying drawings provide a preferred embodiment of a safety control system for arc additive manufacturing of large ship structures. However, a safety control system for arc additive manufacturing of large ship structures can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of a safety control system for arc additive manufacturing of large ship structures more thorough and comprehensive.

[0051] Example 1

[0052] Figure 1A schematic diagram of a safety control system for arc additive manufacturing of large ship structural parts provided by the present invention, the system comprising a virtual contact wall system 1, a human body dynamic distance perception system 2, a virtual protection space system 3, an operation safety protection system 4, and a terminal 5;

[0053] The virtual contact wall system 1 is composed of a plurality of distance sensors 101 evenly distributed on the workpiece base 6. The distance sensors 101 are connected to the workpiece base 6 by screws and can measure the distance between the operator 7 and the workpiece base 6.

[0054] The human body dynamic distance perception system 2 is composed of a depth camera 201 and a mounting plate 202. The depth camera 201 is fixed to the gantry Z-axis arm 8 through the mounting plate 202. The human body dynamic distance perception system 2 can obtain the action information of the operator 7 and calculate the distance between the operator 7 and the welding robot 9.

[0055] The virtual protection space system 3 is established through the kinematic model of the welding robot 9, and the virtual protection space is defined through the working space of the welding robot;

[0056] The operation safety protection system 4 is composed of a plurality of protection fences 401, arc protection plates 402, dust collectors 403, and safety gratings 404. The arc protection plates 402 and safety gratings 404 are installed on the protection fences 401, and the protection fences 401 are arranged around the arc additive manufacturing equipment; the dust collector 403 is arranged around the workpiece base 6 to collect smoke and dust generated during the arc additive process;

[0057] The terminal 5 is used to receive information from the virtual contact wall system 1, the human body dynamic distance perception system 2, the virtual protection space system 3, and the operation safety protection system 4, store, process, and display computer programs, and realize safety control of arc additive manufacturing.

[0058] Example 2

[0059] Figure 2 : is a schematic diagram of the working mechanism of a large-scale ship structure arc additive manufacturing safety prevention and control system provided in this embodiment. The working mechanism or process of the large-scale ship structure arc additive manufacturing safety prevention and control system is:

[0060] A: The operation safety protection system 4 can prevent non-staff from entering the working area and realize arc protection. When the additive manufacturing system is operating, if non-operating personnel enter the working area, the safety grating 404 will alarm through the terminal 5.

[0061] B: When the additive manufacturing system is in operation, the virtual contact wall system 1 is started, the position of the operator 7 is monitored in real time, and the distance between the operator 7 and the workpiece base 6 and the gantry Z-axis arm 8 is calculated; Figure 3As shown, when the virtual contact wall system 1 monitors the position and When it is greater than or equal to R+1m, the virtual protection space system 3 is not started; when the position monitored by the virtual contact wall system 1 and When it is between R+1m and R, the virtual protection space system 3 is initialized; when the position monitored by the virtual contact wall system 1 is and When it is less than or equal to R, the virtual protection space system 3 starts working;

[0062] like Figure 4 As shown, the origin of the coordinate system of the working base platform 5 is O Base The coordinate system origin O of the operator 7 Human The straight-line distance between The calculation process is as follows:

[0063]

[0064] in Represents the operator coordinate system O Human _xyz relative to the workpiece base coordinate system O Base _xyz movement transformation;

[0065] The origin of the coordinate system of the gantry Z-axis arm 8 is O Zaxis The coordinate system origin O of the operator 7 Human The projection distance of the straight-line distance between The calculation process is as follows:

[0066]

[0067] in Represents the operator coordinate system O Human _xyz relative to the gantry Z-axis arm coordinate system O Zaxis _Homogeneous transformation of xyz, Indicates the rotation transformation of the operator coordinate system relative to the gantry Z-axis arm coordinate system, Indicates the movement transformation of the operator coordinate system relative to the gantry Z-axis arm coordinate system;

[0068] C: After the virtual protection space system 3 is started, when the operator 7 enters the virtual protection space, the human body dynamic distance perception system 2 is started; the virtual protection space is obtained by calculating the kinematic model of the welding robot 9, and the kinematic model is expressed as follows:

[0069]

[0070] Where n represents the degree of freedom of the welding robot 9; the boundary of the virtual protection space is the curved surface 301 formed by the farthest distance of the end points of the welding robot 9;

[0071] D: The human body dynamic distance sensing system 2 realizes active safety control by monitoring the minimum distance between each part of the operator 7 and each joint of the welding robot 9;

[0072] When the human body dynamic distance sensing system 2 monitors the minimum distance When the distance is greater than or equal to 1m, the operating speed of the welding robot 9 is reduced to 1m / s; when the minimum distance monitored by the human body dynamic distance sensing system 2 is When the distance is between 0.5m and 1m, the operation speed of the welding robot 9 is reduced to 0.5m / s; when the minimum distance monitored by the human body dynamic distance sensing system 2 When the speed is less than or equal to 0.5 m, the operating speed of the welding robot 9 is reduced to 0.1 m / s;

[0073] Furthermore, the human body dynamic distance perception system 2 establishes a motion model of the operator 7 through the depth camera 201, such as Figure 5 As shown, the coordinates of each part of the operator 7 in the depth camera 201 are obtained. Camera _xyz positions, various parts of the operator 7 include the head 701, neck 702, shoulder 703, chest 704, upper arm 705, abdomen 706, lower arm 707, hand 708, thigh 709, lower leg 710, and foot 711;

[0074] Furthermore, if Figure 6 As shown, the steps for calculating the minimum distance between the operator 7 and the welding robot 9 are as follows:

[0075] D1: The depth camera 201 and the welding robot 9 complete the hand-eye calibration and calculate the depth camera coordinate system O Camera _xyz and welding robot coordinate system O Robot _Homogeneous transformation relationship of xyz

[0076] D2: Calculate the coordinates of each moving joint of the welding robot 9 in the welding robot coordinate system O Robot _xyz pose matrix i represents the i-th joint of the robot, and the mathematical expression is

[0077] D3: Calculate the coordinates of each part of the operator 7 in the depth camera 201 coordinate system O Camera The pose matrix j represents the jth joint of operator 7;

[0078] D4: Calculate the distance between each part of the operator 7 and each joint of the welding robot 9, mathematically expressed as:

[0079]

[0080] D5: Calculate the minimum distance between the operator 7 and the welding robot 9. The mathematical expression is as follows:

[0081]

[0082] Where m represents the number of operator 7 parts.

[0083] The safety control system provided by the present invention combines a variety of sensors and intelligent algorithms, determines the safety status of the system by distance and speed, formulates a hierarchical and multi-mechanism solution, and realizes real-time monitoring and safety control of the human body and robot status when the gantry welding robot is moving and welding, ensuring the safety of production factors of ship structures, and providing reference and basis for the design of arc additive manufacturing systems; the invention improves the safety of the human-in-the-loop welding robot system through depth cameras, distance sensors, etc., monitors risk factors that affect production, and reduces the incidence of safety accidents.

[0084] Example 3

[0085] like Figure 7 As shown, the terminal 5 includes a memory 501, an input unit 502, a display unit 503, a processor 504 and an output unit 505; the memory 501 is used to store computer programs; the input unit 502 is used to receive various instructions or parameters of the virtual contact wall system 1, the human body dynamic distance perception system 2, the virtual protection space system 3, and the operation safety protection system 4; the display unit 503 is used to display various output information of the terminal 5; the processor 504 executes the computer program to enable the terminal to achieve safety control of arc additive manufacturing of large ship structures; the output unit 505 is used to output various control instructions to control the movement of the welding robot 9.

[0086] Matters not covered in the present invention are known technologies. The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A safety control system for arc additive manufacturing of large ship structures, characterized in that: It includes a virtual contact wall system (1), a human body dynamic distance perception system (2), a virtual protection space system (3), an operation safety protection system (4) and a terminal (5); The virtual contact wall system (1) comprises a plurality of distance sensors (101) evenly distributed on a workpiece base (6), wherein the distance sensors (101) are connected to the workpiece base (6) by screws and are used to measure the distance between an operator (7) and the workpiece base (6); The human body dynamic distance perception system (2) comprises a depth camera (201), a mounting plate (202) and a terminal (5); the depth camera (201) is fixed to a gantry Z-axis arm (8) via the mounting plate (202); the human body dynamic distance perception system (2) is used to obtain motion information of an operator (7) and calculate the distance between the operator (7) and the welding robot (9); The virtual protection space system (3) is established through the kinematic model of the welding robot (9), and the virtual protection space is defined through the working space of the welding robot; The operation safety protection system (4) comprises a plurality of protection fences (401), arc protection plates (402), dust collectors (403) and safety gratings (404); the arc protection plates (402) and safety gratings (404) are installed on the protection fences (401); the protection fences (401) are arranged around the arc additive manufacturing equipment; the operation safety protection system (4) is used to prevent non-staff from entering the working area and to achieve arc protection; the dust collector (403) is arranged around the workpiece base (6) to collect smoke and dust generated during the arc additive process; The terminal (5) is used to receive information from the virtual contact wall system (1), the human body dynamic distance perception system (2), and the virtual protective space system (3), store, process, and display computer programs, and realize safety control of arc additive manufacturing.

2. A safety control system for arc additive manufacturing of large ship structures according to claim 1, characterized in that: The virtual contact wall system (1) measures the distance between an operator (7) and a workpiece base (6), comprising: Calculate the origin O of the coordinate system of the work base (5) Base and the operator (7) coordinate system origin O Human The straight-line distance between for: in Represents the operator coordinate system O Human _xyz relative to the workpiece base coordinate system O Base _xyz movement transformation; Calculate the origin O of the gantry Z-axis arm (8) coordinate system Zaxis and the operator (7) coordinate system origin O Human The projection distance of the straight-line distance between The calculation process is: in Represents the operator coordinate system O Human _xyz relative to the gantry Z-axis arm coordinate system O Zaxis _Homogeneous transformation of xyz, Indicates the rotation transformation of the operator coordinate system relative to the gantry Z-axis arm coordinate system, Indicates the movement transformation of the operator coordinate system relative to the gantry Z-axis arm coordinate system.

3. A safety control system for arc additive manufacturing of large ship structures according to claim 2, characterized in that: When the virtual contact wall system (1) monitors the position and When it is greater than or equal to R+1m, the virtual protection space system (3) is not activated; when the position monitored by the virtual contact wall system (1) and When it is between R+1m and R, the virtual protection space system (3) is initialized; when the position monitored by the virtual contact wall system (1) and When it is less than or equal to R, the virtual protection space system (3) starts working; wherein R represents the working radius of the welding robot (9).

4. A safety control system for arc additive manufacturing of large ship structures according to claim 1, characterized in that: The kinematic model of the virtual protection space system (3) established by the welding robot (9) is: Wherein n represents the degree of freedom of the welding robot (9); the boundary of the virtual protection space is a curved surface (301) formed by the farthest distances of the end points of the welding robot (9); when the operator (7) enters the virtual protection space, the human body dynamic distance perception system (2) is activated.

5. The arc additive manufacturing safety control system for large ship structural parts according to claim 1 is characterized in that: The human body dynamic distance perception system (2) establishes a motion model of the operator (7) through a depth camera (201) to obtain the coordinates of various parts of the operator (7) in the depth camera (201) coordinate system. Camera _xyz position, and obtain the minimum distance between the operator (7) and the welding robot (9).

6. A safety control system for arc additive manufacturing of large ship structures according to claim 5, characterized in that: A motion model of the operator (7) is established by using the depth camera (201) to obtain the coordinates of various parts of the operator (7) in the depth camera (201) coordinate system O Camera _xyz position, and obtain the minimum distance between the operator (7) and the welding robot (9), specifically including: Step 1: The depth camera (201) and the welding robot (9) complete the hand-eye calibration and calculate the depth camera coordinate system O Camera _xyz and welding robot coordinate system O Robot _Homogeneous transformation relationship of xyz Step 2: Calculate the coordinates of each moving joint of the welding robot (9) in the welding robot coordinate system O Robot _xyz pose matrix i represents the i-th joint of the robot, expressed as Step 3: Calculate the coordinates of each part of the operator (7) in the depth camera (201) coordinate system O Camera The pose matrix j represents the jth joint of the operator (7); Step 4: Calculate the distance between each part of the operator (7) and each joint of the welding robot (9), which can be expressed mathematically as: Step 5: Calculate the minimum distance between the operator (7) and the welding robot (9), which is expressed as: Where m represents the number of parts of the operator (7).

7. A safety control system for arc additive manufacturing of large ship structures according to claim 6, characterized in that: The various parts of the operator (7) include the head (701), neck (702), shoulders (703), chest (704), upper arms (705), abdomen (706), lower arms (707), hands (708), thighs (709), lower legs (710), and feet (711).

8. A safety control system for arc additive manufacturing of large ship structures according to claim 6, characterized in that: When the minimum distance monitored by the human body dynamic distance sensing system (2) When the distance is greater than or equal to 1m, the operating speed of the welding robot (9) is reduced to 1m / s; when the minimum distance monitored by the human body dynamic distance sensing system (2) When the distance is between 0.5m and 1m, the operating speed of the welding robot (9) is reduced to 0.5m / s; when the minimum distance monitored by the human body dynamic distance sensing system (2) When the speed is less than or equal to 0.5 m, the operating speed of the welding robot (9) is reduced to 0.1 m / s.

9. A safety control system for arc additive manufacturing of large ship structures according to claim 1, characterized in that: The terminal (5) comprises a memory (501), an input unit (502), a display unit (503), a processor (504) and an output unit (505); the memory (501) is used to store computer programs; the input unit (502) is used to receive various instructions or parameters of a virtual contact wall system (1), a human body dynamic distance perception system (2), a virtual protective space system (3), and an operation safety protection system (4); the display unit (503) is used to display various output information of the terminal (5); the processor (504) executes the computer program so that the terminal can realize safety control of arc additive manufacturing of large ship structural parts; and the output unit (505) is used to output various control instructions to control the movement of a welding robot (9).

10. A safety control method for arc additive manufacturing of large ship structures based on the system described in any one of claims 1 to 9, characterized in that: include: When the additive manufacturing system is operating, if a non-operating person enters the working area, the safety grating (404) will sound an alarm through the terminal (5); When the additive manufacturing system is in operation, the virtual contact wall system (1) is activated to monitor the position of the operator (7) in real time, and to calculate the distance between the operator (7) and the workpiece base (6) and the gantry Z-axis arm (8). When the distance is detected to be less than a set value, the virtual protective space system (3) is activated; When the virtual protection space system (3) is activated, when the operator (7) enters the virtual protection space, the human body dynamic distance perception system (2) is activated; The human body dynamic distance sensing system (2) realizes active safety control by monitoring the minimum distance between each part of the operator (7) and each joint of the welding robot (9).

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