Ship welding production line equipment joint control system and missing point compensation method

Abstract

The application provides a ship welding production line equipment joint control system and a missing point position compensation method. The method comprises the following steps: a PLC-intelligent controller hybrid architecture is built to realize seamless integration of new and old equipment; a three-layer mapping method is used to identify missing control point positions; missing point positions are compensated through hardware upgrade and software development, and a control algorithm is optimized. The system comprises existing PLCs, intelligent controllers, newly added sensors and actuators, and an upper monitoring interface. The production line comprises the above system. The application solves the problems of poor compatibility, low control precision and missing key positions of the existing production line, improves the welding quality and production efficiency, and has high reliability, scalability and remote maintenance capability.

Description

Technical Field

[0001] This invention belongs to the field of automated control technology for ship welding, specifically relating to a joint control system for ship welding production line equipment and a method for compensating for missing points, applicable to the upgrading and transformation of production lines with high precision requirements such as section welding and hull welding of large ships. Background Technology

[0002] Ship welding production lines are a core component of shipbuilding, and their level of automation and control precision directly impact welding quality and production efficiency. Welding quality includes aspects such as weld strength and surface smoothness. Currently, ship welding production lines commonly suffer from the following problems:

[0003] 1. Poor compatibility of the control system. Existing production lines mostly use traditional PLC control systems, which have limited expandability. It is difficult to connect new position sensors and energy medium metering equipment, resulting in the inability to collect equipment operation data in real time and to achieve full-process monitoring. Energy medium metering equipment includes natural gas flow, electricity consumption, and other metering.

[0004] 2. Missing key control points; Due to insufficient consideration of equipment linkage requirements in the initial design of the production line, there are common problems such as "missing automatic trolley delivery signal" (manual confirmation of trolley position is required, which can easily lead to positioning deviation ≥5mm), "no closed-loop control of conveyor speed" (speed fluctuation ±0.5m / min, affecting the coordination accuracy between welding robot and conveyor line), and "delay of start and stop signal" (delay time ≥1s, which can easily cause material conveying jams or welding interruptions), which directly affect the consistency of welding quality.

[0005] 3. Low equipment collaboration efficiency; Traditional PLC systems can only achieve independent control of a single device and cannot form joint control with newly added equipment, resulting in slow linkage response speed between welding robots, trolleys, conveyor lines and other equipment, with a response delay of ≥2s, many production process breakpoints, and low per capita productivity.

[0006] 4. Insufficient control precision: Most existing control algorithms are open-loop control, lacking real-time feedback and adjustment of equipment position and speed. When the production line load changes, such as differences in the weight carried by the trolley, control deviations are prone to occur, requiring frequent manual intervention, which increases operating costs and quality risks.

[0007] To address the aforementioned issues, there is an urgent need for a comprehensive solution that is compatible with existing systems, fills in control gaps, and improves the automation level and control precision of ship welding production lines. Summary of the Invention

[0008] In view of this, the purpose of this invention is to provide a joint control system for ship welding production line equipment and a method for compensating for missing points, so as to solve the problems of poor compatibility, low control accuracy and missing key points in the prior art.

[0009] In a first aspect, embodiments of the present invention provide a method for compensating for missing points in a ship welding production line equipment control system, comprising the following steps:

[0010] S1. Deploy intelligent controllers and supporting modules, connect them to the existing PLC control system of the ship welding production line, and connect new sensors and metering equipment to realize real-time acquisition and monitoring of equipment location and energy medium information;

[0011] S2. Conduct a thorough inspection of the existing automated control system of the welding line, identify and determine the missing key control points, including at least the automatic trolley delivery detection point, the conveyor speed adjustment point, and the precise control point for the start and stop of the conveyor.

[0012] S3. For the missing points identified in S2, upgrade the hardware and develop the software, supplement the corresponding control modules, actuators and control logic, and optimize the control algorithm.

[0013] S4. Debug the communication stability, data acquisition accuracy, and control effect after compensation for missing points of the PLC-intelligent controller hybrid architecture to ensure that production needs are met.

[0014] Specifically, S2 employs a three-layer mapping method of equipment-process-location to identify missing locations, including:

[0015] Equipment layer: Review the control requirements for welding robots, trolley conveying equipment, conveyor lines, and energy supply devices;

[0016] Process layer: This corresponds to the material conveying before welding, equipment coordination during welding, and finished product transfer after welding, clearly defining the linkage control nodes;

[0017] Point layer: Locate control points not covered in each process and identify key problem points.

[0018] Preferably, the intelligent controller and supporting modules in S1 include:

[0019] Guide rails are used to support various functional modules;

[0020] The power module is used to supply power to the system.

[0021] Analog input module, used to acquire analog signals from position sensors and energy medium metering sensors;

[0022] The communication module is used to enable communication and interconnection between the intelligent controller and the existing PLC system and new equipment;

[0023] The data storage module is used to back up system parameters and production data, and supports remote access and download.

[0024] Preferably, the hardware upgrade in S3 includes:

[0025] Supplement with a laser displacement sensor for detecting the trolley's arrival position;

[0026] A variable frequency speed control module is added and connected to the intelligent controller to realize closed-loop control of the conveyor line speed;

[0027] A relay module was added to the motor control circuit of the conveyor line to optimize the start / stop signal triggering logic.

[0028] Preferably, the software development in S3 includes:

[0029] Write a communication program between the intelligent controller and the PLC, supporting the Modbus protocol;

[0030] Write the control logic code for the missing points, using ladder diagram programming;

[0031] Optimize the PID control algorithm to improve equipment response speed and control accuracy.

[0032] Preferably, the PID control algorithm has an adaptive function, which can automatically adjust the control parameters according to load changes.

[0033] Secondly, the ship welding production line equipment control system includes:

[0034] Existing PLC control system;

[0035] The intelligent controller connects to the PLC system via a communication module;

[0036] Add new sensors and actuators, which are then connected to the system via an intelligent controller;

[0037] The upper-level monitoring interface is used to display real-time data on equipment location, conveyor speed, and energy consumption.

[0038] Preferably, the intelligent controller integrates an analog input module and a communication module, and is connected to the frequency converter and relay module via a CC bus.

[0039] Preferably, it also includes a remote monitoring terminal, which is connected to the intelligent controller via Ethernet to realize remote monitoring, parameter setting and fault diagnosis.

[0040] Preferably, the communication module adopts a dual-redundancy design to ensure communication reliability.

[0041] The embodiments of the present invention bring the following beneficial effects:

[0042] 1. Hybrid architecture compatibility and investment protection: Adopting a hybrid PLC-intelligent controller architecture, it does not replace the original PLC system and can quickly connect new sensors, actuators and metering equipment, achieving seamless integration of new and old equipment, maximizing the protection of the original investment in the production line, and reducing the transformation cycle and cost;

[0043] 2. Accurate and efficient point identification: Through the three-layer mapping method of equipment process points, missing control points are systematically located, avoiding omissions and misjudgments in manual inspection, greatly improving the efficiency of point identification and providing a reliable basis for accurate compensation;

[0044] 3. Comprehensive leap in control precision: After compensation, the trolley positioning deviation is ≤0.5mm, the conveyor speed fluctuation is ≤0.1m / min, and the start / stop response delay is ≤0.5s, which is significantly better than traditional open-loop control, ensuring that the welding trajectory and cycle time are highly consistent.

[0045] 4. Enhanced adaptive disturbance rejection capability: The adaptive PID algorithm can automatically adjust parameters according to changes in load and operating conditions, suppressing problems such as speed drift and positioning overshoot, and maintaining stable control under heavy load and variable load conditions, reducing manual intervention;

[0046] 5. Highly efficient equipment control and coordination: The linkage logic between trolleys, conveyor lines, and welding robots is integrated, with equipment response delay ≤0.5s, eliminating process breakpoints, improving production line cycle consistency, and significantly improving per capita productivity and overall efficiency;

[0047] 6. Full-process data visualization and management: Real-time collection of data such as location, speed, and energy medium, synchronous display on the host computer and remote terminal, supporting data traceability, statistical analysis and report generation, providing support for process optimization and energy consumption management;

[0048] 7. System safety, redundancy and reliability: Dual-path redundancy of communication modules, automatic parameter backup, fault self-diagnosis and remote maintenance reduce the rate of unexpected downtime, extend the continuous operation time of equipment, and improve the stability and availability of the production line;

[0049] 8. Significant energy saving and consumption reduction: Precise control of energy supply and equipment start-up and shutdown reduces idling and ineffective energy consumption. Actual measurements show that it can reduce energy consumption such as natural gas and electricity by 6%-7%, balancing production efficiency and green manufacturing.

[0050] 9. Intelligent and Simplified Operation and Maintenance: Supports remote monitoring, parameter tuning, fault early warning and log analysis, realizing the transformation from "reactive maintenance" to "predictive maintenance", reducing on-site operation and maintenance intensity and labor costs;

[0051] 10. Strong scalability: It is not only suitable for ship section and hull welding production lines, but can also be extended to the upgrading and transformation of high-precision welding production lines such as wind turbine towers, construction machinery, and heavy steel structures, making it highly versatile;

[0052] Other features and advantages of the invention will be set forth in the following description, and some features will be obvious from the description or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description, claims, and drawings.

[0053] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0054] Figure 1 A schematic diagram of the PLC-intelligent controller hybrid architecture provided by the present invention;

[0055] Figure 2 This is an installation layout diagram of the intelligent controller module provided by the present invention within the control cabinet;

[0056] Figure 3 This is a schematic diagram of the missing point compensation control process provided by the present invention;

[0057] Figure 4 Example diagram of the system debugging and monitoring interface provided by the present invention. Detailed Implementation

[0058] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0059] Example 1

[0060] This embodiment provides a method for compensating for missing points in the joint control system of ship welding production line equipment, including the following steps:

[0061] S1. Deploy intelligent controllers and supporting modules, connect them to the existing PLC control system of the ship welding production line, and connect new sensors and metering equipment to realize real-time acquisition and monitoring of equipment location and energy medium information;

[0062] Specifically, based on the existing PLC control system, an intelligent controller is introduced as the core expansion unit. The PLC and the intelligent controller are seamlessly connected through the intelligent controller 351 communication module, forming a hybrid control mode in which "PLC is responsible for basic equipment control + intelligent controller is responsible for new equipment access and data monitoring".

[0063] Furthermore, the intelligent controller and its supporting modules include:

[0064] Guide rails are used to support various functional modules;

[0065] The power module is used to supply power to the system.

[0066] Analog input module, used to acquire analog signals from position sensors and energy medium metering sensors;

[0067] The communication module is used to enable communication and interconnection between the intelligent controller and the existing PLC system and new equipment;

[0068] The data storage module is used to back up system parameters and production data, and supports remote access and download.

[0069] S2. Conduct a thorough inspection of the existing automated control system of the welding line, identify and determine the missing key control points, including at least the automatic trolley delivery detection point, the conveyor speed adjustment point, and the precise control point for the start and stop of the conveyor.

[0070] The method employs a three-tiered mapping approach—equipment-process-location—to identify missing control points, creating a list of missing control points. This list clarifies the functional requirements (e.g., "trolley positioning detection" requires ±0.5mm position deviation feedback), signal type (analog / digital), and installation location of each point. Specifically,

[0071] Equipment layer: Review the control requirements for welding robots, trolley conveying equipment, conveyor lines, and energy supply devices;

[0072] Process layer: This corresponds to the material conveying before welding, equipment coordination during welding, and finished product transfer after welding, clearly defining the linkage control nodes;

[0073] Point layer: Locate control points not covered in each process and identify key problem points.

[0074] S3. For the missing points identified in S2, upgrade the hardware and develop the software, supplement the corresponding control modules, actuators and control logic, and optimize the control algorithm.

[0075] The hardware upgrades include:

[0076] Supplement with a laser displacement sensor for detecting the trolley's arrival position;

[0077] A variable frequency speed control module is added and connected to the intelligent controller to realize closed-loop control of the conveyor line speed;

[0078] A relay module was added to the motor control circuit of the conveyor line to optimize the start / stop signal triggering logic.

[0079] Furthermore, software development includes:

[0080] Write a communication program between the intelligent controller and the PLC, supporting the Modbus protocol;

[0081] Write the control logic code for the missing points, using ladder diagram programming;

[0082] The PID control algorithm is optimized to improve the equipment's response speed and control accuracy. Furthermore, the PID control algorithm has an adaptive function, which can automatically adjust the control parameters according to load changes.

[0083] Specifically, the adaptive PID control algorithm can automatically adjust parameters in real time according to the trolley load weight and the conveyor running speed: the system collects load changes through sensors and combines them with real-time speed feedback to automatically adjust the proportional coefficient Kp, integral coefficient Ki, and derivative coefficient Kd, so as to achieve no shaking under heavy load, no overshoot under light load, and speed fluctuation ≤ ±0.1m / min. No need for repeated manual debugging, improving the equipment's collaborative stability and welding consistency.

[0084] S4. Debug the communication stability, data acquisition accuracy, and control effect after compensation for missing points of the PLC-intelligent controller hybrid architecture to ensure that production needs are met.

[0085] The PLC-intelligent controller hybrid architecture and missing point compensation method adopted in this invention are not only suitable for the automation upgrade and transformation of ship welding production lines, but can also be widely applied to welding and conveying production lines in various heavy equipment manufacturing fields such as wind turbine towers, engineering machinery, marine engineering equipment, and steel structure manufacturing. It can quickly adapt to old equipment, make up for the shortcomings of control points, improve the accuracy of linkage control and production efficiency, and has strong versatility and expansion value.

[0086] Example 2

[0087] This embodiment provides a joint control system for ship welding production line equipment, including:

[0088] Existing PLC control system;

[0089] The intelligent controller integrates an analog input module and a communication module. It connects to the frequency converter and relay module via the CC bus and to the PLC system via the communication module. The communication module adopts a dual-redundant design to ensure communication reliability.

[0090] Add new sensors and actuators, which are then connected to the system via an intelligent controller;

[0091] The supervisory control interface is used to display real-time data on equipment location, conveyor speed, and energy consumption.

[0092] The remote monitoring terminal connects to the intelligent controller via Ethernet to enable remote monitoring, parameter setting, and fault diagnosis.

[0093] It should be noted that the intelligent controller is equipped with dual storage redundancy and automatic data backup mechanism. System parameters, production data, and point logs support dual backup on both local and cloud. The backup cycle is configurable, and data is not lost in the event of power failure and is traceable in the long term. The communication module adopts a dual-redundancy design, with one main channel and one backup channel, which automatically switches to ensure uninterrupted communication between the intelligent controller and PLC, sensors, and actuators. The communication latency is stable at ≤100ms, which meets the high reliability operation requirements of the welding production line.

[0094] In addition, the system supports remote monitoring, fault early warning and log analysis: remote terminals can view equipment status, point signals and energy consumption data in real time via Ethernet; the intelligent controller can diagnose point anomalies, communication failures and actuator failures in real time, actively report alarm information and locate the cause; the system automatically generates operation logs, fault records and debugging records, which can be viewed, exported and traced remotely, realizing remote maintenance, unattended operation and rapid troubleshooting, and greatly reducing on-site maintenance costs.

[0095] Example 3

[0096] Taking the upgrade of a large container ship hull welding production line as an example, the specific implementation steps are as follows:

[0097] S1 and PLC-Intelligent Controller Hybrid Architecture Construction

[0098] Module Procurement and Inspection: Procure Hanpu intelligent controller modules (1 RACK011 DIN rail, 1 intelligent controller 372 power supply, 3 intelligent controller 336 analog modules, and 2 intelligent controller 351 communication modules), and inspect whether the module specifications (such as the 16-bit A / D accuracy of intelligent controller 336 and the CC bus compatibility of intelligent controller 351) meet the requirements;

[0099] Module installation: Fix RACK011 guide rails (flatness deviation ≤0.2mm) inside the production line control cabinet, and install the following in sequence: Intelligent Controller 372 power supply (connected to AC220V mains power), 3 Intelligent Controller 336 modules (connected to the laser displacement sensor, natural gas flow meter, and electricity meter respectively), and 2 Intelligent Controller 351 modules (one connected to the existing PLC (model S7-1200) via CC bus, and the other connected to the conveyor line frequency converter).

[0100] Communication test: Write a Modbus communication program between the intelligent controller and the PLC, test the data transmission rate (≥1Mbps) and latency (≤100ms) to ensure that the device location and energy data can be uploaded to the upper monitoring interface in real time.

[0101] S2. Missing Control Points Analysis

[0102] Equipment layer analysis: List the core equipment such as welding robot (model ABB IRB 6700), trolley conveyor (load capacity 5t), conveyor line (length 20m), natural gas supply unit, etc., and clarify the control interface and signal type of each piece of equipment;

[0103] Process layer mapping: Corresponding to the process of "cart feeding → conveyor line transfer → welding robot operation → finished product output", problems were found such as "no arrival signal after the cart arrives at the welding station", "the conveyor line speed cannot be adjusted according to the welding rhythm", and "the start and stop of the conveyor line is not synchronized with the robot operation".

[0104] Point-level location: Identify missing points as "cart arrival detection points", "conveyor line speed closed-loop control points", and "start-stop linkage control points", and form a "List of Missing Points".

[0105] S3, Implementation of Compensation for Missing Locations

[0106] Hardware upgrades include,

[0107] Cart positioning detection: Laser displacement sensors (model Keyence IL-1000) are installed on both sides of the welding station, outputting 4-20mA analog signals, which are connected to the 336 intelligent controller module, and the detection accuracy is set to ±0.5mm;

[0108] Conveyor speed control: A variable frequency speed controller (Schneider ATV320) is installed next to the conveyor motor (11kW power), and connected to the intelligent controller controller through the intelligent controller 351 module to achieve speed adjustment from 0-5m / min;

[0109] Start-stop linkage control: A solid-state relay (model Omron G3NA) was added to the motor control circuit of the conveyor line, and the signal triggering logic was optimized to reduce the start-stop delay from 1.2s to 0.3s;

[0110] Software development includes,

[0111] Control logic programming: Ladder diagrams are used to write the code to implement the linkage logic of "laser displacement sensor detects the trolley is in position → intelligent controller sends signal to PLC → PLC triggers the conveyor line to decelerate (from 3m / min to 1m / min) → welding robot starts operation";

[0112] Algorithm optimization: A PID algorithm is used for the speed control of the conveyor line. The proportional coefficient Kp is set to 2.5, the integral coefficient Ki to 0.5, and the derivative coefficient Kd to 0.1. By collecting the speed feedback signal from the conveyor line encoder in real time, the output of the frequency converter is dynamically adjusted to keep the speed fluctuation within ±0.1m / min.

[0113] S4. System Debugging and Operation

[0114] Single-machine debugging: Test the effectiveness of trolley positioning detection (trolley stops multiple times, position deviation ≤0.5mm), conveyor speed control (speed adjusted from 1m / min to 5m / min, fluctuation ≤0.1m / min), and start / stop linkage (delay between conveyor start / stop and robot operation ≤0.5s).

[0115] Joint debugging: Simulate the complete welding process to test the coordination effect of "trolley-conveyor line-robot" to ensure no jamming or deviation issues;

[0116] Long-term operation: Continuous operation for 30 days, monitoring system stability (failure rate ≤0.5%), welding quality (weld pass rate ≥98%), and energy consumption (natural gas consumption reduced by 7%, electricity consumption reduced by 6%) to confirm that the production line requirements are met.

[0117] S5. Acceptance and Delivery

[0118] The design, quality, and production departments conducted the acceptance test to confirm that the PLC-intelligent controller hybrid architecture had stable communication, adequate compensation for missing points, and met control accuracy standards. An acceptance report was then generated and the system was handed over to the production department for official use.

[0119] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0120] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for compensating for missing points in the joint control system of ship welding production line equipment, characterized in that, Includes the following steps: S1. Deploy intelligent controllers and supporting modules, connect them to the existing PLC control system of the ship welding production line, and connect new sensors and metering equipment to realize real-time acquisition and monitoring of equipment location and energy medium information; S2. Conduct a thorough inspection of the existing automated control system of the welding line, identify and determine the missing key control points, including at least the automatic trolley delivery detection point, the conveyor speed adjustment point, and the precise control point for the start and stop of the conveyor. S3. For the missing points identified in S2, upgrade the hardware and develop the software, supplement the corresponding control modules, actuators and control logic, and optimize the control algorithm. S4. Debug the communication stability, data acquisition accuracy, and control effect after compensation for missing points of the PLC-controller hybrid architecture to ensure that production needs are met. Specifically, S2 employs a three-layer mapping method of equipment-process-location to identify missing locations, including: Equipment layer: Review the control requirements for welding robots, trolley conveying equipment, conveyor lines, and energy supply devices; Process layer: This corresponds to the material conveying before welding, equipment coordination during welding, and finished product transfer after welding, clearly defining the linkage control nodes; Point layer: Locate control points not covered in each process and identify key problem points.

2. The method for compensating for missing points in the joint control system of ship welding production line equipment according to claim 1, characterized in that, The intelligent controller and supporting modules in S1 include: Guide rails are used to support various functional modules; The power module is used to supply power to the system. Analog input module, used to acquire analog signals from position sensors and energy medium metering sensors; The communication module is used to enable communication and interconnection between the intelligent controller and the existing PLC system and new equipment; The data storage module is used to back up system parameters and production data, and supports remote access and download.

3. The method for compensating for missing points in the joint control system of ship welding production line equipment according to claim 1, characterized in that, The hardware upgrade in S3 includes: Supplement with a laser displacement sensor for detecting the trolley's arrival position; A variable frequency speed control module is added and connected to the intelligent controller to realize closed-loop control of the conveyor line speed; A relay module was added to the motor control circuit of the conveyor line to optimize the start / stop signal triggering logic.

4. The method for compensating for missing points in the joint control system of ship welding production line equipment according to claim 1, characterized in that, The software development in S3 includes: Write a communication program between the intelligent controller and the PLC, supporting the Modbus protocol; Write the control logic code for the missing points, using ladder diagram programming; Optimize the PID control algorithm to improve equipment response speed and control accuracy.

5. The method for compensating for missing points in the joint control system of ship welding production line equipment according to claim 4, characterized in that, The PID control algorithm has an adaptive function, which can automatically adjust the control parameters according to load changes.

6. A ship welding production line equipment control system for implementing the method of any one of claims 1-5, characterized in that, include: Existing PLC control system; The intelligent controller connects to the PLC system via a communication module; Add new sensors and actuators, which are then connected to the system via an intelligent controller; The upper-level monitoring interface is used to display real-time data on equipment location, conveyor speed, and energy consumption.

7. The ship welding production line equipment control system according to claim 6, characterized in that, The intelligent controller integrates an analog input module and a communication module, and is connected to the frequency converter and relay module via a CC bus.

8. The ship welding production line equipment control system according to claim 6, characterized in that, It also includes a remote monitoring terminal, which connects to the intelligent controller via Ethernet to enable remote monitoring, parameter setting, and fault diagnosis.

9. The ship welding production line equipment control system according to claim 6, characterized in that, The communication module adopts a dual-redundancy design to ensure communication reliability.

10. A ship welding production line, characterized in that, Includes the equipment control system described in any one of claims 6-9.

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