CN108442436B

CN108442436B - Full-automatic and manual dredging system of trailing suction hopper dredger and switching control method

Info

Publication number: CN108442436B
Application number: CN201810180776.4A
Authority: CN
Inventors: 缪袁泉; 张晴波; 丁琪; 任蔓延; 周振燕
Original assignee: CCCC National Engineering Research Center of Dredging Technology and Equipment Co Ltd
Current assignee: CCCC National Engineering Research Center of Dredging Technology and Equipment Co Ltd
Priority date: 2018-03-05
Filing date: 2018-03-05
Publication date: 2020-09-18
Anticipated expiration: 2038-03-05
Also published as: CN108442436A

Abstract

The full-automatic and manual dredging system comprises the existing manual control PLC on the dredger, a dredging pipeline, a dredging gate valve, a high-pressure water pipeline, a high-pressure flushing butterfly valve, a hydraulic pump, a water sealing pump and a gate valve flushing pump, wherein the arrangement of the dredging gate valve on the dredging pipeline and the arrangement of the high-pressure flushing gate valve on the high-pressure water pipeline are the prior art of the dredger And (5) working process.

Description

Full-automatic and manual dredging system of trailing suction hopper dredger and switching control method

Technical Field

The invention belongs to the technical field of ocean dredging engineering.

Background

A drag suction dredger is a special engineering ship, is provided with a drag head, a drag pipe, a dredge pump, a dredge cabin, a dredge door, a pumping cabin door, a high-pressure flushing pump and other special devices, and drags and sucks silt from the water bottom during slow navigation to load the cabin, and quickly navigates to a mud throwing area to unload mud or blow the bank after the cabin is filled with the silt. Traditionally, the equipment is controlled by a manual control PLC to carry out manual construction operation.

Manual dredging or semi-automatic dredging: the operating instructions are sent to the manual control PLC through the handle or the button, and then the manual control PLC sends the commands to each actuating mechanism. During the whole operation process, the manual judgment is carried out, the rake arm is operated to push out the outboard when appropriate, the outboard is placed to the construction excavation depth, a dredging gate valve and a flushing butterfly valve are preset, and a series of equipment such as a dredge pump, a water sealing pump and a high-pressure flushing pump are started to carry out the dredging. During the period, the posture of the harrow arm is continuously observed, and the construction safety is ensured by adjusting the retraction of a harrow arm winch. The mud concentration is adjusted by adjusting the rotating speed of the mud pump and the high-pressure flushing pump, and the time points of overflow and end of dredging are judged by the draught and loading of the ship. The above process is the existing operation flow and construction process in the industry.

The trailing suction hopper dredger controls different objects in each dredging process. During construction, ship drivers need to control the ship to sail in a busy port channel and send dredging instructions, so that the ship drivers think that the ship is in a high-pressure and tense state, and wrong sailing and dredging instructions can be sent to cause safety accidents. The dredging operation is the operation combining ship navigation and dredging, and ship driving control personnel are respectively operated by a plurality of persons, so that the construction thinking of the opposite side is often misunderstood among the ship personnel due to incompact or other reasons, the construction efficiency is influenced, and the ship safety accident can be caused in serious cases.

Disclosure of Invention

The invention firstly constructs a full-automatic dredging control system of the trailing suction hopper dredger and an implementation method thereof, and can solve the problems in the manual operation of the traditional construction, so that the invention can realize the full-automatic control 'one-man bridge' technology of the trailing suction hopper dredger, and simultaneously the invention further provides the seamless switching technology between the 'manual-full-automatic' system and the traditional manual system. The invention can realize automation of ship dredging construction, ensure the safety of dredging equipment, improve the dredging efficiency and reduce the labor cost and fuel consumption.

The technical scheme of the invention to be protected is summarized as follows:

a full-automatic control system for dredging of a trailing suction hopper dredger comprises the prior art of the trailing suction hopper dredger, which comprises the existing manual control PLC on the dredger, a dredging pipeline, a dredging gate valve, a high-pressure water pipeline, a high-pressure flushing butterfly valve, a hydraulic pump, a water sealing pump and a gate valve flushing pump, wherein the arrangement of the dredging gate valve on the dredging pipeline and the arrangement of the high-pressure flushing gate valve on the high-pressure water pipeline are adopted, it is characterized by also comprising a master control PLC, an automatic dredging pipe system gate valve control subsystem, an automatic dredge pump control subsystem, a high-pressure flushing control subsystem, an automatic low-concentration discharge control subsystem, a rake arm winch automatic control subsystem, an active rake head control subsystem and a loading draft control subsystem which are controlled by the master control PLC, the full-automatic control system is designed and operated on a master control PLC system, and each functional subsystem cooperates with other functional subsystems by controlling the operation of an executing mechanism in the system, so that the full-automatic working process of the whole dredging system is realized on the premise of ensuring the dredging safety.

The fully automatic dredging call relationship is shown in fig. 1.

The dredging pipe system gate valve control subsystem automatically opens and closes 18 dredging gate valves on the dredging pipe according to working conditions and flow so as to ensure that the corresponding pipe is smooth. The subsystem comprises a manual control PLC and a dredging pipe system gate valve controller (ADSS for short), and the manual control PLC is used for controlling the opening and closing of various dredging gate valves to form different mode combinations.

The dredging pipe system gate valve controller defines 11 automatic preset modes, and the control algorithm of each mode is the prior art as follows:

x: the state of the valve in this mode is not critical and may not be considered.

C: in this mode it is off during the entire set-up.

C¹: in the dredge mode it is initially closed and later allowed to open.

C²: in the blow-fill mode, it is initially closed and later allowed to open.

O: in this mode it is open during the entire setup.

O¹: in the dredge mode it is initially open and later allowed to close.

O²: initially open in the blow-fill mode, later let throughIt is allowed to shut down.

The mud pump control subsystem is used for adjusting the rotating speed of the mud pump so as to keep reasonable mud concentration and flow rate of the mud pipeline. The subsystem comprises a manual control PLC, a mud pump controller (APC for short), a mud concentration meter, a mud flow rate meter, a mud pump suction vacuum sensor and a mud pump discharge pressure sensor. The mud concentration meter and the mud flow rate meter are arranged on the dredging pipeline and used for collecting the concentration and the flow rate information of the dredging mud entering the pipeline, and the information is provided for the master control PLC through the manual control PLC and is called by each functional subsystem in the system. The suction vacuum sensor and the discharge pressure sensor are respectively arranged at the suction end and the discharge end of the dredge pump and are used for acquiring suction vacuum degree and discharge pressure information of the dredge pump, and the information is provided for the master control PLC through the manual control PLC and is called by the dredge pump controller and other subsystems. The output of the dredge pump controller is connected with a frequency converter of the dredge pump through a manual control PLC, and the dredge pump controller is used for driving a motor to adjust the rotating speed of the dredge pump, and finally the purpose of adjusting the concentration and the flow rate of the slurry is achieved.

The mud pump controller adjusts the rotating speed of the mud pump through a mud pump rotating speed optimizing algorithm, so that the monitoring of the concentration and the flow speed of the mud in the pipeline is realized. The dredge pump rotating speed optimizing algorithm is characterized as follows:

the low-concentration discharge control subsystem comprises a manual control PLC and a low-concentration discharge controller (ALMO for short), wherein the low-concentration discharge controller is used for selecting and determining the proper slurry in the current dredging pipeline to enter a cabin or discharge the slurry out of the cabin by controlling the combined action of a cabin entering gate valve (D011-D014) and a bypass gate valve (D009-D010) through the manual control PLC by monitoring the real-time slurry flow rate and concentration at the master control PLC.

The emission control algorithm is as follows:

the high-pressure water flushing control subsystem forms high-pressure water and is sprayed out by the drag head in the dredging process, the effect of auxiliary soil breaking and stirring is achieved on the drag head, and the dredging concentration is optimal by adjusting the stirring state of the drag head in real time, so that the dredging efficiency is greatly improved.

The subsystem comprises a manual control PLC, a high-pressure flushing pipeline, a high-pressure flushing controller (AJC for short), a high-pressure flushing pump and a pressure sensor, and the relation is as follows: the output end of the high-pressure flushing pipeline is a drag head and can spray high-pressure water. The high-pressure flushing pump is used for forming high-pressure water and controlling the water pressure of the high-pressure flushing pipeline by adjusting the rotating speed. The pressure sensor is arranged at the discharge end of the high-pressure flushing pump and used for collecting the pressure of high-pressure water in the high-pressure flushing pipeline, and the information is provided for the high-pressure flushing controller through the manual control PLC. The output of the high-pressure flushing controller is connected with a frequency converter of the high-pressure flushing pump through a manual control PLC, the driving motor is controlled to adjust the rotating speed of the high-pressure flushing pump through an optimization algorithm of the high-pressure flushing controller according to the current construction soil quality and system parameter setting, so that the discharged water pressure is adjusted, the rake head soil is stirred in different degrees, and the purpose of adjusting the slurry concentration is finally achieved.

The high-pressure flushing optimizing algorithm is a PID control algorithm, the control model utilizes real-time high-pressure flushing pressure and real-time slurry concentration information at the main control PLC, current parameters and target parameters of the high-pressure flushing pressure and the slurry concentration information are compared to form closed-loop feedback to design, and target values of the high-pressure flushing pressure and the slurry concentration are set for different slurry qualities. The high-pressure flushing optimization algorithm is characterized as follows:

the automatic control subsystem of the harrow arm winch comprises a manual control PLC, a harrow arm winch automatic controller (STAWC), a harrow pipe winch and a wave compensator, wherein the harrow arm winch controller (STAWC) controls the harrow pipe winch and the wave compensator through the manual control PLC to realize the depth control of the harrow head, and simultaneously, the safety of equipment and a ship body is ensured by detecting and adjusting an included angle between harrow pipes and the distance between the harrow pipes and the ship body through the manual control PLC. The full-automatic control module of the harrow tube winch comprises a bent tube winch control module, a harrow winch control module and a harrow head winch control module, wherein the bent tube winch control module is used for detecting and ensuring that a bent tube is lowered to the position of a suction port, and providing reference depth for the control of a follow-up harrow winch and a harrow head winch; the drag winch control module is used for controlling the drag winch to follow the drag head winch to act, and the control aim is to keep the posture of the drag arm in a straight line all the time; the drag head winch control module is used for controlling the drag head to be lowered to a target depth, and comprises wave compensator control and fixed depth control, so that the ship is constructed within a set excavation depth and a set compensation range of the wave compensator.

The active rake control subsystem comprises an active rake controller (ADHC) that: the rake lip is kept at a set ground angle under the condition of ensuring safety, a thick mud layer can be cut by the rake lip in a deep digging mode, and the system realizes the functions by controlling the retraction of the rake lip oil cylinder. The active drag head control module has the function of keeping the drag lips attached to the ground under the condition of ensuring the safety of the active drag head, and controls the oil cylinder to receive and release the drag lips to keep the drag lips attached to the ground all the time by setting four control parameters of action duration T1, action interval time T2, automatic feeding pressure P1, energy accumulator constant tension pressure P2 and angle dead zone beta. When the drag of the drag head is increased and the pressure of the drag lip oil cylinder exceeds the set value P2 of the energy accumulator, the hydraulic system is passively retracted into the oil cylinder to lift the drag lip. Because the energy accumulator action of the trailing lip is unidirectional, the pushing of the trailing lip oil cylinder is provided with energy by a hydraulic pump (the energy is only suitable for the equipment conditions and conditions in the prior art, and the energy accumulator action does not belong to the innovation point of the technical scheme). The drag head automatic control module continuously detects the stroke of the oil cylinder, when the angle change exceeds an angle dead zone beta, the drag head automatic control module controls the oil cylinder to be pushed out by pressure P1 within a set time interval T2, the action duration of the oil cylinder is T1 each time until the angle of the drag lip returns to the initial set value, if the angle of the drag lip cannot return to the initial set value within the time interval T2, the drag lip is contracted by the hydraulic pump to be at the maximum angle.

The loading draft control subsystem includes a loading draft controller (abbreviated as: ALDC) for determining when to initiate an overflow and when the tanks are full, thereby determining the end of the dredging of the vessel. The loading draft control algorithm is as follows: and taking a dredging and loading curve of a certain ship after entering the construction area as a reference, and judging the time point when the loading is finished by comparing the tangent slope of the loading curve in the subsequent ship operation. Fig. 2 shows the loading curve of the dredger dredge. O is an original point, t is a time axis, M is a loading amount axis, and A, B, C, D points are loading amounts corresponding to the moments A ', B', C 'and D'. From the point O to the point A, the slope AA'/OA can be approximately regarded as a straight line, and the loading efficiency is highest. A curve with gradually reduced slope is formed from the point A to the point B, and the curve shows that the tank filling and overflowing are carried out simultaneously, and the tank filling amount is larger than the overflowing amount. The slope of the curve from point B to point C continues to decrease, indicating that the overflow gradually increases and slowly approaches the load. If the time is extended indefinitely, a dynamic equilibrium will be reached where the hold volume equals the overflow volume, as shown at point D. As shown in fig. 2, point a is the start point of the overflow, and point B is the most efficient point to end the dredging. A. The point B is also the reference point of the subsequent construction ship.

The main control PLC's full-automatic main flow of dredging calls 7 full automatic control wares respectively according to current process of dredging, and every controller is responsible for the control to relevant equipment, and then realizes full-automatic control of dredging. The main process of the full-automatic control of the master control PLC is as follows:

1) and (5) preparation work, which is mainly used for starting the hydraulic pump, the water sealing pump and the gate valve flushing pump.

2) The automatic controller (STAWC) of the harrow arm winch executes the water inlet of a harrow pipe to ensure that a suction port of a bent pipe is in place and the underwater depth of a harrow head is fixed.

3) According to the setting of the pre-dredging parameters, the dredging pipe system gate valve control subsystem controls the dredging gate valve thereof, and enables the corresponding pipeline to be smooth under the selected mode; the master control PLC controls the high-pressure flushing butterfly valve to enable the high-pressure pipeline to be smooth.

4) The mud pump control subsystem starts the mud pump and adjusts the rotating speed of the mud pump in real time to monitor the concentration and the flow rate of mud in the mud pipe. Meanwhile, the high-pressure flushing pump control subsystem of the invention starts the high-pressure flushing pump, adjusts the rotating speed of the high-pressure flushing pump, and adjusts the high-pressure water pressure of the flushing rake head, thereby finally achieving the purpose of adjusting the concentration of the mud in the mud pipe.

5) The two controllers of the drag arm winch automatic controller (STAWC) and the Active Drag Head Controller (ADHC) realize underwater cooperative control of the drag pipe and the drag head on the premise of ensuring the safety of the dredging drag pipe, ensure that the drag head is attached to a mud surface at an optimal angle, ensure the optimal dredging concentration and further greatly improve the dredging efficiency.

6) When the mud pump of the mud pump control subsystem drives mud to flow in the pipeline, the flow rate and concentration information of the mud in the mud pipe on the pipeline are provided for the master control PLC in real time, the low-concentration discharge controller monitors the flow rate and concentration information of the mud in real time, and when the mud concentration meets the requirement of loading the cabin, the low-concentration discharge controller controls the opening of the gate valve (D011-D014) for entering the cabin and controls the mud to be loaded into the mud cabin. When the concentration of the slurry is lower than the loading requirement or the flow rate is higher than the loading requirement, the bypass gate valve (D009-D010) is opened to directly discharge the slurry out of the board.

7) When a loading gate valve, namely a' loading gate valve (D011-D014), is opened and slurry of a dredging pipeline begins to be injected into the cabin, the loading draft control subsystem searches time points of loading, overflowing and ending dredging by comparing the set tangent slope of a loading curve.

8) The automatic controller (STAWC) of the harrow arm winch realizes that the harrow arm is folded to a suction port three-pipe flat state, and goes out of the water surface at a set angle, so that water in the harrow pipe naturally flows out and carries silt which is not washed clean in the harrow pipe out; after staying for a set time, the harrow tube is upwards retracted to the outboard highest position, then retracted into the inboard, and finally placed on the resting pier.

The invention provides a full-automatic control implementation method for underwater dredging, which is unmanned in the whole control process and free of human intervention, and automatically completes the dredging operation process. The invention can ensure the safety of the dredging equipment and improve the dredging construction efficiency. Because degree of automation is high, greatly reduced human cost and fuel consumption.

Drawings

Fig. 1 is a diagram illustrating a fully automatic dredging call relationship.

FIG. 2 is a graph of the dredging loading capacity.

FIG. 3 is a top view of the traverse section of the drag head

Fig. 4 is a logic relationship diagram of the fully automatic control technology of the harrow tube.

FIG. 5 is a flow chart of the winch control in the harrow in FIG. 4 (embodiment 1)

FIG. 6 is a flow chart of the drag winch control in FIG. 4 (embodiment 1)

FIG. 7 is a flow chart of the automatic control of the active rake head of FIG. 4 (embodiment 1)

FIG. 8 is a basic parameter setting interface for the dredging (embodiment 2)

FIG. 9 is a flow chart of the full-automatic dredging of embodiment 2 (embodiment 2)

FIG. 10 is a flow chart of the automatic dredging function cut-in of example 3

FIG. 11 is a flow chart of the automatic dredging function in example 3

FIG. 12 is a schematic diagram of a system control structure according to the present invention

Detailed Description

The technical solution of the present invention is further described below with reference to the following embodiments and the accompanying drawings. It should be noted that the dredging pipeline, the dredging gate valve, the high-pressure water pipeline, the hydraulic pump, the high-pressure flushing gate valve, the hydraulic pump, the water sealing pump, the gate valve flushing pump, the harrow pipe winch (including the elbow winch, the harrow center winch and the harrow head winch), the harrow arm (upper and lower harrow pipes), the harrow head, the universal joint, the wave compensator, the energy accumulator, the harrow lip hydraulic cylinder and the hydraulic system thereof, etc. mentioned in the technical scheme of the present invention are all common equipments equipped for the harrow suction dredger.

Example 1

Full-automatic control chronogenesis of dredging includes three stages: setting before dredging, preparing for dredging and automatically dredging.

1. Before dredging set up

Before preparation for dredging, parameters are required to be set for the dredging process, the parameters play a role in restraining or selecting the dredging process, and basic parameters mainly comprise the number of construction rakes, the state of a high-pressure flushing pump in the construction process, triggering conditions for stopping the high-pressure flushing pump and the dredge pump, the overtime time of the dredging preparation and the water inlet posture of a rake pipe, as shown in figure 8.

2. Preparation for dredging

After the full-automatic dredging control instruction is artificially selected, the system firstly performs self-checking and preparation work. The preparation work mainly finishes starting the hydraulic pump, sealing the water pump and the flushing pump, the gate valve is preset to be in a single-rake bypass mode or a double-rake bypass mode according to parameter setting, and the butterfly valve is preset to be in a serial-connection rake flushing head or a single-pump rake flushing head or a complete closing mode according to parameter setting.

3. Automatic dredging

1) When the harrow tube is placed on the block, the harrow tube automatically rises from the block to the inboard highest position, then is pushed from the inboard highest position to the outboard highest position, then the harrow tube is put down to the elbow suction port in place from the outboard highest position according to the water inlet posture of the harrow tube, and the three-tube horizontal position is stopped;

2) when the harrow pipe is positioned at the position where the elbow suction port is in place and the horizontal position of the three pipes, the automatic controller of the harrow arm winch is called, the fixed depth control of the harrow head is realized by controlling the harrow pipe winch and the wave compensator, and the safety of equipment and a ship body is ensured by detecting and adjusting the included angle between the harrow pipes and the distance between the harrow pipes and the ship body.

3) Meanwhile, according to the setting of the parameters before dredging, a dredging pipe system gate valve controller is called, and the dredging gate valve and the high-pressure flushing butterfly valve are preset, so that the pipeline is smooth.

4) And then, starting the dredge pump and the high-pressure flushing pump, calling a dredge pump controller, monitoring the slurry concentration and the flow rate, and adjusting the rotating speed of the dredge pump through an optimization algorithm. And (4) calling a high-pressure flushing pump controller, adjusting the rotating speed of the high-pressure flushing pump through the vacuum degree and the pressure discharge of the dredge pump, and finally adjusting the pressure of the high-pressure water rushing out of the drag head.

5) When the harrow head is at the bottom, the harrow head driving harrow head controller is started to be called, the harrow lip is kept attached to the ground by retracting and releasing the harrow lip oil cylinder, a thicker mud layer can be cut under a specific condition, and the construction efficiency is improved.

6) When the mud pump drives the mud to flow in the pipeline, and the mud concentration is read, the low-concentration discharger is started to be called, the mud flow rate and the mud density are monitored, and when the mud concentration meets the loading requirement, the ALMO controller controls the 'gate valve for entering the cabin' to be opened, and controls the mud to be loaded into the mud cabin. When the concentration of the slurry is lower than the loading requirement or the flow rate is higher than the loading requirement, the bypass gate valve is opened to directly discharge the slurry out of the board.

7) When the loading gate valve is opened and slurry begins to be injected into the tank, the system calls the loading draft controller, the point with the highest loading efficiency is found by comparing the set tangent slope of the loading curve or the estimated loading time, and a loading stop command is output according to draft change in the process so as to prevent draft from exceeding the limit and ensure the safety of ship construction and navigation.

8) And when the loading earth volume meets the set value, the construction is considered to be finished. The system automatically stops and calls the automatic controller of the harrow arm winch, the active harrow head controller, the automatic loading draught controller, the automatic dredge pump controller and the automatic high-pressure flushing pump controller.

9) And simultaneously, the rake arm is synchronously retracted, and when the three pipes of the suction port are in a flat state, the system stops calling the automatic low-concentration discharger and stops the mud pump and the high-pressure flushing pump. And (4) the water begins to flow out of the water surface at a set angle, so that the water in the harrow tube naturally flows out, and the silt which is not washed out in the harrow tube is carried out.

10) After staying for a set time, the harrow tube starts to be continuously folded upwards to reach the outboard highest position, then is collected into the inboard, and finally is placed on the resting pier.

11) So far, the construction of the full-automatic dredging is completely finished.

The fully-automatic control of the harrow tube as shown in fig. 3 comprises safety control, fully-automatic control of a harrow tube winch and fully-automatic control of an active harrow head, wherein the safety control runs through the fully-automatic control of the harrow tube winch and the fully-automatic control of the active harrow head. Firstly, the full-automatic control of the pipe harrow winch is used for realizing that the harrow head is lowered to the target depth, and after the full-automatic control of the pipe harrow winch is completed, the full-automatic control of the harrow head is realized through the automatic control of the angle of the harrow lip when the active harrow head works at the bottom of the ground, and the function of the pipe harrow winch is to ensure that the harrow lip keeps close to the ground under the condition of ensuring the safety of the active harrow head.

And the elbow winch control is used for detecting and ensuring that the elbow is lowered to the suction port position, and providing reference depth for the control of a follow-up drag winch and a drag head winch.

And further giving a control algorithm of the drag winch, and controlling the drag winch to follow the drag head winch to move all the time on the premise of ensuring safe operation so as to ensure that the drag arm is in a good posture, namely in a straight line. As shown in fig. 5:

the method comprises the following steps: and (4) meeting the starting condition of starting the drag head winch, and starting the automatic control module of the drag pipe winch.

Step two: and (3) detecting whether the vertical included angle (namely universal joint angle control) of the upper and lower harrow tubes is less than the maximum value of the set angle within 1s, if so, re-detecting, otherwise, entering the third step.

Step three: and (4) detecting whether the vertical angle difference 1s between the upper and lower harrow tubes is a negative value, if so, entering the sixth step, otherwise, entering the fourth step.

Step four: and (4) detecting whether the vertical angle 1s of the upper and lower harrow tubes is positive, if so, entering the fifth step, and otherwise, entering the second step.

Step five: the drag winch is raised.

Step six: the drag winch descends.

Further providing a drag winch control algorithm, controlling the drag to be lowered to the target depth on the premise of ensuring the safe operation, as shown in fig. 6:

Step two: and (4) checking whether the transverse offset distance of the drag head is greater than the inboard and outboard limit positions (shown in figure 3), if so, entering a third step, and otherwise, entering a fifth step.

Step three: the drag head winch is raised.

Step four: and (4) detecting whether the lateral offset distance of the drag head winch is in a safe area (shown in figure 3), if so, entering a step five, and otherwise, entering a step three.

Step five: and detecting whether the wave compensator is higher than the set value by 0.5m within 2s, if the wave compensator is maintained to be higher than 0.5m, entering a step six, and if not, entering a step eleven.

Step six: and detecting whether the difference between the digging depth set value and the actual digging depth is larger than 0.5m, if so, entering a seventh step, and otherwise, entering a ninth step.

Step seven: the drag head winch is raised.

Step eight: and (4) detecting whether the heave compensator returns to the position of +0.3m of the set value, if so, entering the step two, and if not, entering the step seven.

Step nine: the drag head winch is raised.

Step ten: and (4) detecting whether the wave compensator returns to the set value position, if so, entering the step two, and otherwise, entering the step nine.

Step eleven: and detecting whether the actual digging depth is less than the set digging depth within 2s, if so, entering a step twelve, and otherwise, entering a step two.

Step twelve: the drag head winch descends.

Further, an active drag head full-automatic control algorithm is provided, and on the premise of ensuring safe operation, the drag head is always controlled to be in an angle with the ground to adapt to the underground terrain state, so that efficient operation is maintained, as shown in fig. 7:

the method comprises the following steps: and (4) meeting the starting condition of starting the automatic control of the drag head, and starting the automatic control module of the drag head.

Step two: according to the vertical angle of the lower harrow tube, the harrow lip is adjusted to move to a set angle relative to the ground by retracting and releasing the hydraulic oil cylinder.

Step three: and (4) detecting whether the pressure of the rake lip exceeds a set value P2 of the accumulator, if so, entering the step four, otherwise, continuing to detect.

Step four: and detecting whether the change of the angle of the rake lip to the ground exceeds a set angle dead zone beta, if so, entering a fifth step, and if not, returning to the third step.

Step five: during the set time interval T2, the control cylinder is pushed out at pressure P1, and the duration of each cylinder action is T1.

Step six: detecting whether the rake lip angle exceeds the time interval T2 in the process of returning to the initial set value, if not, returning to the step three, if so, entering the step seven.

Step seven: the retractable rake lip is at the maximum angle, and the system gives an alarm and quits.

Further explanation is given:

firstly, fully automatically controlling a harrow tube winch and realizing the lowering of a harrow head to a target depth. The full-automatic control module of the harrow tube winch comprises a bent tube winch control module, a harrow winch control module and a harrow head winch control module, wherein the bent tube winch control module is used for detecting and ensuring that a bent tube is lowered to a suction port position, and provides reference depth for the control of a follow-up harrow winch and a harrow head winch; the drag winch control module is used for controlling the drag winch to follow the drag head winch to act, and the control aim is to keep the posture of the drag arm in a straight line all the time; the drag head winch control module is used for controlling the drag head to be lowered to a target depth, and comprises wave compensator control and fixed depth control, so that the ship is constructed within a set excavation depth and a set compensation range of the wave compensator.

Given as an example, the controlling the heave compensator comprises setting the heave compensator pressure, the set pressure of the heave compensator being adjusted between 80% and 20% of the working pressure depending on the construction soil mass from silt to fine sand.

Setting pressure gauge of compensator

Soil texture	Percentage of operating pressure
		Sludge	80％
Silt	60％
		Clay clay	40％
Fine silt	20％

The control of the wave compensator also comprises height control of the wave compensator, and on the premise of meeting the depth control, the height of the wave compensator is kept at about 0.3m by adjusting the extension and retraction of the drag head winch, so that the cutting thickness of the drag lip to the ground is ensured.

The depth control is implemented by taking the embodiment as an example, the depth control is implemented by enabling a ship to be constructed in a set excavation depth and a set compensation range of a heave compensator, and if the heave compensator exceeds a set stroke range, the drag head winch is automatically controlled to be retracted and placed to ensure that the excavation depth is in the set range. The dredging depth can be automatically compensated according to the actual tide level according to the tide of 0m in the aspect of setting the dredging depth. As an embodiment, there is disclosed: when the difference between the digging depth set value and the actual digging depth is larger than 0.5m, after the drag head is grounded, if the stroke of the wave compensator exceeds the set value by 0.5m, the drag head winch is retracted, and the plunger of the wave compensator returns to the set value position. When the difference between the digging depth set value and the actual digging depth is less than or equal to 0.5m, if the stroke of the wave compensator is greater than 0.5m, the drag head winch is retracted, and the plunger of the wave compensator returns to the position of 0.3 m. And when the digging depth set value is equal to the actual digging depth, controlling the drag head winch to enable the stroke of the plunger of the wave compensator to be 0 meter.

And secondly, when the harrow head is placed at the target depth under the full-automatic control of the harrow pipe winch, the full-automatic control technology of the harrow head automatically controls the angle of the harrow lip when the active harrow head works at the bottom of the ground, the function of the full-automatic control technology of the harrow head is to ensure that the harrow lip keeps a preset angle to the ground under the condition of ensuring the safety of the active harrow head, and the function is realized by controlling the retraction and extension of a harrow lip oil cylinder. In the full-automatic dredging control process, the oil cylinder is controlled to be retracted and released for adjusting the rake lip to keep the rake lip attached to the ground all the time by setting four control parameters of action duration T1, action interval time T2, automatic feeding pressure P1, energy accumulator constant tension pressure P2 and angle dead zone beta. When the drag of the drag head is increased and the pressure of the drag lip oil cylinder exceeds the set value P2 of the energy accumulator, the hydraulic system is passively retracted into the oil cylinder to lift the drag lip. Because the energy accumulator action of the trailing lip is unidirectional, the pushing of the trailing lip oil cylinder is provided with energy by a hydraulic pump (the energy is only suitable for the equipment conditions and conditions in the prior art, and the energy accumulator action does not belong to the innovation point of the technical scheme). The drag head automatic control module continuously detects the stroke of the oil cylinder, when the angle change exceeds an angle dead zone beta, the drag head automatic control module controls the oil cylinder to be pushed out by pressure P1 within a set time interval T2, the action duration of the oil cylinder is T1 each time until the angle of the drag lip returns to the initial set value, if the angle of the drag lip cannot return to the initial set value within the time interval T2, the drag lip is contracted by the hydraulic pump to be at the maximum angle.

The safety protection is always taken as the premise of algorithm design, and the following aspects are reflected:

1) heave compensator control

The system gives an alarm when the stroke of the wave compensator is changed beyond the response capability of the system due to unforeseen sudden factors.

2) Lateral control

If the horizontal rake head offset exceeds the lateral offset limit, the rake pipe automatic control will lift the rake head to a lateral safety zone. The lateral offset range generated according to the lateral offset limit value is divided into an outboard limit position, an outboard safety margin, a drag head center line, an inboard safety margin, and an inboard limit position, as shown in fig. 3.

The lateral offset limit is suitably increased when the cut depth exceeds two thirds of the maximum design cut depth.

3) Universal joint angle control

It is known in the art that the universal joint is a transition device connecting the upper and lower harrow plates, which can swing within a certain angular range in both the up-down and left-right directions. In the aspect of swing angle control, the vertical included angle between the upper and lower harrow tubes does not exceed 15 degrees by retracting and releasing the winch in the harrow.

According to the full-automatic control method for the dredging harrow pipe of the trailing suction hopper dredger, the dredging efficiency can be optimized on the premise of ensuring the safety of the dredging harrow pipe by performing full-automatic accurate cooperative control on a plurality of ship equipment such as a harrow pipe winch, a wave compensator, an active harrow head and the like.

Example 2

The system has the characteristics and the working mode that:

(1) before dredging set up

The full-automatic dredging control needs to set parameters of the dredging process before construction preparation, the parameters play a role in restricting or selecting the dredging process, the basic parameters mainly comprise the number of construction rakes, the state of a high-pressure flushing pump in the construction process, the triggering conditions of stopping the high-pressure flushing pump and the dredge pump, the overtime time of the dredging preparation and the water inlet posture of a rake pipe, and the parameters are shown in figure 8.

(2) Control process

When the full-automatic mud digging is carried out, the system firstly carries out self-checking and preparation work.

Then the harrowing pipe is lifted from the rest pier → highest position → pushed out → lowered to the third pipe flat → the mud pump is started, the water pump is sealed, the high pressure flushing pump → the relevant automatic controller is called → the mud is started → the relevant automatic controller is called → the mud is ended → the relevant automatic controller is closed → the harrowing pipe is lifted to the third pipe flat → the relevant automatic controller is closed → the harrowing pipe is lifted to the highest position → the harrowing pipe is retracted, the harrowing pipe is placed on the rest pier

The invention needs to protect the technical scheme of the embodiment 2:

referring to fig. 9, the fully automatic dredging control algorithm is detailed as follows:

the method comprises the following steps: pressing the macro button to 'fully-automatically dredge' starts dredging.

Step two: preparation for dredging begins.

Step three: a dredge preparation timer is started.

Step four: and starting system self-checking.

Step five: and judging whether the hydraulic system is available, if not, entering a step six, and if the hydraulic system is available and the starting is successful, entering a step eight.

Step six: and (5) judging whether the hydraulic system fails to start, if so, entering a seventh step, and if not, returning to a fifth step.

Step seven: and sending out an overtime alarm for starting the hydraulic pump.

Step eight: the water seal pump is started.

Step nine: the gate valve flush pump is started.

Step ten: judging whether the dredging pipe system is in a bypass mode or not, and if not, entering the eleventh step. If so, go to step fourteen.

Step eleven: and (4) presetting the dredging gate valve.

Step twelve: judging whether the preset of the dredging gate valve is overtime or not, if not, returning to the step ten. If time out, enter step thirteen.

Step thirteen: and sending out a preset overtime alarm of the gate valve.

Fourteen steps: and (5) ending the preparation of dredging, judging whether the preparation process is overtime, and if so, entering the step fifteen. If not, step sixteen is entered.

Step fifteen: and sending an overtime alarm for mud digging preparation.

Sixthly, the steps are as follows: and (5) beginning to put the rake.

Seventeen steps: the harrow tube is lifted and pushed out to the highest outboard position.

Eighteen steps: the elbow was placed to the mouthpiece and the three tubes were flat.

Nineteen steps: and continuously lowering the harrow pipe.

Twenty steps: and judging whether the dredge pump is in harmony discharge or not, and if not, entering the twenty-one step. If yes, the procedure goes to twenty-six.

Twenty one: and judging whether the operating conditions of the dredge pump are met, and if not, entering the twenty-two step.

If yes, go to step twenty three.

Step twenty-two: and sending out an alarm that the operating condition of the dredge pump is not met.

Twenty-three steps: the dredge pump starts to operate.

Twenty-four steps: and circularly monitoring whether the stop condition of the dredge pump is met, if so, entering twenty-five step, and if not, entering twenty-six step.

Twenty-five steps: the dredge pump stops running and gives an alarm.

Twenty-six steps: and judging whether the pre-dredging parameter setting needs to use a high-pressure flushing pump. If yes, go to twenty-seven. If not, go to step thirty-two.

Twenty-seven steps: and judging whether the running conditions of the high-pressure flushing pump are met, if not, entering twenty-eight step, and if so, entering twenty-nine step.

Twenty-eight steps: and sending out a prompt that the running condition of the high-pressure flushing pump is not met.

Twenty-nine steps: the high pressure flush pump begins to run.

Thirty steps are as follows: and circularly judging whether the stopping condition of the high-pressure flushing pump is met, if so, entering the thirty-one step, and if not, entering the thirty-two step.

Thirty-one steps: the high pressure flushing pump stops running and gives an alarm.

Step thirty-two: and (4) starting to call the automatic control STAWC of the harrow arm winch, the automatic low-concentration discharge controller ALMO and the active harrow head controller ADHC, and adjusting the front and rear cabin inlet gate valves.

Step thirty three: and judging whether the parameter setting of the automatic controller STAWC of the harrow arm winch is legal or not, and if not, entering a thirty-four step. If so, go to step thirty-five.

Thirty-four steps: and sending out an illegal alarm of parameter setting of the automatic controller STAWC of the harrow arm winch.

Step thirty-five: activating the rake arm winch automatic controller STAWC and if the activation is unsuccessful, proceeding to step thirty-six. If the activation is successful, go to step fifty one.

Step thirty-six: and sending an automatic jumping-out alarm of the automatic controller STAWC of the harrow arm winch.

Step three seventeen: and judging whether the ALMO parameter setting of the automatic low-concentration discharge controller is reasonable or not, and if not, entering a thirty-eight step. If reasonable, go to step thirty-nine.

Step thirty-eight: and sending an illegal alarm of the ALMO parameter setting of the automatic low-concentration discharge controller.

Step thirty-nine: the automatic low level emission controller ALMO is activated and if the activation is unsuccessful, step forty is entered. If the activation is successful, go to step fifty one.

Step forty: and sending an automatic low-concentration discharge controller ALMO automatic jump alarm.

Step forty one: and judging whether the parameter setting of the active rake head controller ADHC is reasonable or not, and if not, entering the step forty-two. If so, go to step forty-three.

Step forty-two: and sending an illegal alarm of the setting of the parameters of the active rake head controller ADHC.

Step forty-three: and activating the active rake controller ADHC, and if the activation is unsuccessful, entering the forty-four step. If the activation is successful, go to step fifty one.

Fourteen steps: and sending an automatic jump alarm of the active rake head controller ADHC.

Step forty-five: and adjusting the front and rear cabin inlet gate valve.

Step forty-six: and judging whether the difference between the fore and aft draft is more than 0.5, if so, returning to the forty-five step. If not, go to step forty-seven.

Step forty-seven: and judging whether the ALDC parameter setting of the automatic loading draft controller is reasonable or not, and if not, entering the forty-eight step. If reasonable, go to step forty-nine.

And forty-eight steps: and sending out an illegal alarm for setting parameters of the automatic loading draft controller ALDC.

Step forty-nine: the automatic loading draft controller ALDC is activated and if the activation is unsuccessful, step fifty is entered. If the activation is successful, go to step fifty one.

Step fifty: and sending an automatic loading draft controller ALDC automatic jumping alarm.

Fifthly, steps: when the set construction completion condition is met, the rake is collected.

Step fifty-two: the remaining 6 controllers, except the automatic low level emission controller ALMO, were stopped.

Fifthly, steps: the three pipes are lifted according to a certain posture.

Fifthly, fourteen steps: and judging whether the pump is stopped according to the lifting distance or not by setting the parameters before dredging. If so, go to step fifty-five. If not, go to step fifty-six.

Step fifty five and fifteen: and if the rake head lifting distance exceeds a set value, returning to the fifty-three step. If so, go to step fifty-seven.

Fifty-six steps: and judging whether the bent pipe reaches the suction port and achieving a three-pipe flat state. If not, returning to the step fifty three. If so, go to step fifty-seven.

Fifthly, steps: stop the dredge pump, stop the high pressure flush pump, stop the automatic low concentration discharge controller ALMO.

Step fifty-nine: and continuously lifting the harrow pipe to the highest position outside the ship board, and placing the harrow pipe at the place of the rest pier after being retracted.

Sixty steps: the water seal pump and the gate valve flushing pump are stopped.

Sixty-one steps: and finishing the full-automatic dredging control flow.

Example 3

By installing a set of fully automatic dredging system as disclosed in embodiment 1 and embodiment 2 of the present invention on the trailing suction hopper dredger already equipped with a manual dredging system, fully automatic dredging operation can be achieved, and the dredging process can be optimized and improved.

The full-automatic dredging system is additionally provided with a full-automatic dredging control platform on the basis of a manual dredging system, and the full-automatic dredging control platform comprises a computer, a set of Siemens S7-400PLC system and an HMI touch screen. And the computer and the PLC are communicated with the ring network of the ship control system through the Ethernet. The computer is provided with a touch function display used for displaying an SCADA interface specially customized for the dredging system, and is also provided with a customized DTPM program used for partially fully-automatic function parameter setting. The HMI is mainly used for control command input of operators and parameter setting macro button running state indication of the automatic controller. The manual control PLC is then responsible for the reception of the sensor signals and the control of the dredging equipment.

A trailing suction hopper dredger provided with a full-automatic control system and a manual control system relates to the control authority switching of 2 sets of full-automatic control systems and manual control systems. During the construction process of the drag suction dredger, a plurality of high-power heavy equipment runs at a high speed, and during the construction process, manual/automatic switching is sometimes required under the condition that the equipment runs, because manual and full-automatic control systems are two completely independent control systems, how to process the running dredging equipment in the switching process becomes more important. The simple and violent stopping or starting of the equipment reduces the construction efficiency and even directly damages the equipment to cause unnecessary loss.

Under the circumstances, embodiment 3 of the present invention provides a method for controlling switching between a fully automatic dredging system and a manual dredging system of a drag suction dredger, which realizes seamless switching control between the fully automatic dredging system and the manual dredging system and can solve the above problems. The full-automatic and manual dredging switching control of the trailing suction dredger can ensure construction safety, and the construction efficiency and the adaptability of a full-automatic dredging system are improved.

The invention aims to realize the seamless switching of the full-automatic control mode and the manual control mode of the trailing suction hopper dredger, and the control method is safe, efficient and easy to operate and popularize. The switching between the original manual control system and the fully automatic dredging system on the target vessel in the normal state is selected by a universal change-over switch arranged on the fully automatic control platform, the universal change-over switch is provided with two gears which are switched in and out:

1. cutting into

The cut-in refers to the state that a dredging system of the trailing suction hopper dredger is changed from a manual control state to an automatic control state. When the operator puts the gear into this state, indicating that the fully automatic control is valid, the fully automatic function selection can be performed by operating the corresponding macro button on the HMI at this time. The cut-in operation needs to be started in the next PLC scanning period after the remote control manual operation is finished, the full-automatic master control PLC replaces the traditional remote control manual PLC to carry out logic judgment after the cut-in operation is finished, and the remote control manual PLC only keeps the I/O driving purpose. The steps of the plunge are as follows, and the corresponding flow chart is shown in fig. 10.

The method comprises the following steps: an operator turns the universal change-over switch to a cut-in gear;

step two: detecting whether a conventional PLC for controlling the manual dredging system acts or not, and if so, entering a third step; if no action is taken, entering a step four;

step three: controlling a PLC of the automatic dredging system to output a fault state to a red signal lamp on a workbench to indicate that the cut-in is unsuccessful, and waiting for the end of the scanning period of the conventional PLC;

step four: the conventional PLC outputs a 'cut-in permission' command to the automatic PLC, and after the automatic PLC receives the command, the automatic PLC outputs an automatic state to a green signal lamp on the workbench, and simultaneously outputs a signal to lock the conventional PLC, so that the cut-in is successful, and the dredging process is automatically controlled.

2. Cutting out

Cutting-out refers to the conversion of the dredging system of the trailing suction hopper dredger from an automatic control state to a manual control state. In this state, the full-automatic control is disabled, the operator cannot perform any macro button-related operation, and if the operator performs the macro button operation in this state, the control device does not perform any type of response regardless of the operating conditions. In this state, only the remote control manual PLC is used. The cutting-out step is as follows, and the corresponding flowchart is shown in fig. 11.

The method comprises the following steps: an operator rotates the universal change-over switch to a cut-out gear;

step two: detecting whether the automatic control function operates, if not, entering a third step, otherwise, entering a fourth step;

step three: the automatic PLC outputs a signal to enable the automatic control function operation indicator lamp to be turned off, the automatic control function is invalid, the automatic control function is converted into manual control, and the switching-out is successful;

step four: and detecting whether the automatic control function is in a critical process, if not, entering a step five, and otherwise, entering a step six. The definition of the critical process is explained below.

Step five: stopping the current automatic function, and all outputs are restored to the transition state, namely:

then entering a step three;

step six: keeping all actions, lighting a fault indicator lamp, waiting for manual operation, and entering a seventh step;

step seven: and entering a fifth step after the operator confirms, and entering a sixth step if the operator confirms.

Whether the key process is judged to be mainly referred to by two points:

(1) in some more complex conditions there is a risk of damage to the dredging apparatus itself. If the harrow tube is working underwater and the underwater environment is severe, such as large wave, reef and other working conditions, the possibility that the harrow tube is damaged is high if transition processing is not carried out during cutting-out under the conditions.

(2) When the equipment normally runs, sudden emergency stop can cause huge loss to production, and if the dredge pump suddenly stops during normal operation, pipe blockage can be caused, the production needs to be stopped, and the dredge pump needs to be cleaned, so that the production is stopped. Therefore, a transition stage is also required when cutting out at this time to prevent production stoppage.

During the dredging operation, the schedule list of each equipment is shown in table 1, and the marked points are key schedules, namely, two schedules, namely, a drag arm winch automatic control (STAWC) and an automatic dredge pump control (APC).

TABLE 1 Critical Process List

Controller name	Whether a critical process
		Automatic control of harrow arm winch (STAWC)	√
Active rake head control (ADHC)	X
		Low concentration automatic emission control (ALMO)	X
Automatic mud door control (ABMC)	X
		High pressure flush automatic control (AJC)	X
Automatic Loading Draft Control (ALDC)	X
		Automatic drawing cabin door control (ASEC)	X
Automatic dredge pump control (APC)	√
		Dredging pipe system sluice valve automatic setting (ADSS)	X

And (3) dredging transition state:

during dredging, the following conditions may exist for the dredging apparatus: the harrowing pipe is provided with a laying pier, the harrowing pipe is arranged in a side, the harrowing pipe is arranged outside the side, the mud pump runs, the mud pump does not run, the inboard wave compensator acts, the outboard wave compensator acts, the horizontal included angle of the harrowing pipe is out of limit in the landing process, and the high-pressure flushing acts. Wherein the content of the first and second substances,

(1) when the dredge pump is switched out, a transition state is entered. At the moment, the dredge pump can run for five minutes at the current rotating speed, an operator can adjust the handle within five minutes, the rotating speed of the dredge pump controlled manually is matched with that in an automatic state, and the dredge pump is prevented from stopping running when the rotating speed controlled by the handle is zero after switching;

(2) the outboard heave compensator is switched out during operation and enters a transient state. At the moment, firstly, the wave compensator is locked to pause, then the drag pipe winch is driven to move to lift the drag head for 1 m through emergency linkage, and then the wave compensator is unlocked in response to the speed of the winch controlled by the handle;

(3) when the horizontal included angle of the harrow tube exceeds the limit in the landing process, the harrow tube is cut off and enters a transition state. At this point, the heave compensator is first locked and allowed to pause, then the emergency linkage causes the drag pipe winch to operate and the drag head to lift 1 metre, and then the heave compensator is unlocked in response to the handle controlled winch speed.

(4) And the valve is switched off during high-pressure flushing action, and a transition state is entered. At this time, the high-pressure flushing pump can run for five minutes at the current rotating speed, an operator can adjust the handle within five minutes, the rotating speed of the manually-controlled high-pressure flushing pump is matched with that in the automatic state, and the high-pressure flushing pump is prevented from stopping running when the rotating speed controlled by the handle is zero after switching.

Table 2 shows the operation steps in the case of cutting out in each state

In other states, the switch can be switched out directly.

The invention can realize seamless switching control of a full-automatic and manual dredging system of a trailing suction dredger, and comprises the following steps: hand operated incision Fully automatic and fully automatic switching to manual. The invention is safe, efficient and easy to operate, not only protects the safety of dredging equipment, but also improves the safety of dredging equipment Applicability of a fully automatic dredging system.

Claims

1. A dredging system of a trailing suction dredger comprises the prior art of the trailing suction dredger, which is provided with a manual control PLC, a dredging pipeline, a dredging gate valve, a high-pressure water pipeline, a high-pressure flushing butterfly valve, a hydraulic pump, a water sealing pump and a gate valve flushing pump, wherein the arrangement of the dredging gate valve on the dredging pipeline and the arrangement of the high-pressure flushing gate valve on the high-pressure water pipeline are adopted, it is characterized by also comprising a master control PLC, an automatic dredging pipe system gate valve control subsystem, an automatic dredge pump control subsystem, a high-pressure flushing control subsystem, an automatic low-concentration discharge control subsystem, a rake arm winch automatic control subsystem, an active rake head control subsystem and a loading draft control subsystem which are controlled by the master control PLC, the full-automatic control system is designed to run on a master control PLC system, and each functional subsystem is used for controlling the operation of an executing mechanism in the system to cooperate with other functional subsystems, so that the full-automatic working process of the whole dredging system is realized on the premise of ensuring the dredging safety;

the dredging pipe system gate valve control subsystem automatically opens and closes 18 dredging gate valves on the dredging pipe according to the working condition and the flow so as to ensure that the corresponding pipe is smooth;

the mud pump control subsystem is used for adjusting the rotating speed of the mud pump so as to keep reasonable mud concentration and flow rate of the mud pipeline; the subsystem comprises a manual control PLC, a mud pump controller, a mud concentration meter, a mud flow rate meter, a mud pump suction vacuum sensor and a mud pump discharge pressure sensor; the mud concentration meter and the mud flow rate meter are arranged on the dredging pipeline and are used for acquiring the concentration and the flow rate information of the dredging mud entering the pipeline, and the information is provided for the master control PLC through the manual control PLC and is called by each functional subsystem in the system; the suction vacuum sensor and the discharge pressure sensor are respectively arranged at the suction end and the discharge end of the dredge pump and are used for acquiring suction vacuum degree and discharge pressure information of the dredge pump, and the information is provided for the master control PLC through the manual control PLC and is called by the dredge pump controller and other subsystems; the output of the dredge pump controller is connected with a frequency converter of the dredge pump through a manual control PLC and is used for driving a motor to adjust the rotating speed of the dredge pump, and finally the purpose of adjusting the concentration and the flow rate of the slurry is achieved;

the low-concentration discharge control subsystem comprises a manual control PLC and a low-concentration discharge controller, and the low-concentration discharge controller is used for selecting and determining the proper slurry in the current dredging pipeline to enter a cabin or discharge the slurry out of a board by monitoring the real-time slurry flow rate and concentration at the master control PLC and controlling the combined action of a 'cabin inlet gate valve' and a 'bypass gate valve' through the manual control PLC;

the high-pressure flushing control subsystem forms high-pressure water in the dredging process and sprays the high-pressure water out of the drag head, so that the drag head is assisted in breaking soil and stirring; the subsystem comprises a manual control PLC, a high-pressure flushing pipeline, a high-pressure flushing controller, a high-pressure flushing pump and a pressure sensor, and the relation is as follows: the output end of the high-pressure flushing pipeline is a drag head and can spray high-pressure water; the high-pressure flushing pump is used for forming high-pressure water and controlling the water pressure of the high-pressure flushing pipeline by adjusting the rotating speed; the pressure sensor is arranged at the discharge end of the high-pressure flushing pump and used for collecting the pressure of high-pressure water in the high-pressure flushing pipeline, and the information is provided for the high-pressure flushing controller through the manual control PLC; the output of the high-pressure flushing controller is connected with a frequency converter of a high-pressure flushing pump through a manual control PLC, and the high-pressure flushing controller controls a driving motor to adjust the rotating speed of the high-pressure flushing pump according to the current construction soil quality and system parameter setting, so that the discharged water pressure is adjusted, and the rake head soil is stirred;

the automatic control subsystem of the harrow arm winch comprises a manual control PLC, an automatic controller of the harrow arm winch, a harrow tube winch and a wave compensator, wherein the harrow arm winch controller controls the harrow tube winch and the wave compensator to realize the depth control of a harrow head through the manual control PLC, and simultaneously, the safety of equipment and a ship body is ensured by detecting and adjusting an included angle between harrow tubes and the distance between the harrow tubes and the ship body through the manual control PLC; the full-automatic control module of the harrow tube winch comprises a bent tube winch control module, a harrow winch control module and a harrow head winch control module, wherein the bent tube winch control module is used for detecting and ensuring that a bent tube is lowered to the position of a suction port, and providing reference depth for the control of a follow-up harrow winch and a harrow head winch; the drag winch control module is used for controlling the drag winch to follow the drag head winch to act, and the control aim is to keep the posture of the drag arm in a straight line all the time; the drag head winch control module is used for controlling the drag head to be lowered to a target depth, and comprises wave compensator control and fixed depth control, so that the ship is constructed within a set excavation depth and a set compensation range of the wave compensator;

the active rake head control subsystem comprises an active rake head controller (ADHC), and the active rake head controller (ADHC) enables the rake lip to keep a set ground angle under the condition of ensuring safety and is realized by controlling the retraction and release of the rake lip oil cylinder;

the main full-automatic dredging process of the master control PLC calls 7 full-automatic controllers respectively according to the current dredging process, and each controller is responsible for controlling equipment in the subsystem so as to realize full-automatic dredging control; the main process of the full-automatic control of the master control PLC is as follows:

1) preparation work is mainly completed, and the hydraulic pump, the water sealing pump and the gate valve flushing pump are started;

2) a harrow arm winch automatic controller (STAWC) executes the water inlet of a harrow pipe to ensure that a suction port of the elbow pipe is in place and a harrow head is fixed in depth underwater;

3) according to the setting of the pre-dredging parameters, the dredging pipe system gate valve control subsystem controls the dredging gate valve thereof, and enables the corresponding pipeline to be unblocked under the selected mode; the master control PLC controls the high-pressure flushing butterfly valve to enable the high-pressure pipeline to be smooth;

4) the mud pump control subsystem starts a mud pump of the mud pump control subsystem, and adjusts the rotating speed of the mud pump in real time to monitor the concentration and the flow rate of mud in a mud pipe; meanwhile, the high-pressure flushing pump control subsystem starts the high-pressure flushing pump, adjusts the rotating speed of the high-pressure flushing pump, adjusts the high-pressure water pressure of the flushing rake head and adjusts the slurry concentration in the mud pipe;

5) the two controllers of a rake arm winch automatic controller (STAWC) and an active rake head controller (ADHC) realize underwater cooperative control of a rake pipe and a rake head on the premise of ensuring the safety of a dredging rake pipe, and the rake head is attached to a mud surface;

6) when a mud pump of the mud pump control subsystem drives mud to flow in a pipeline, the information of the flow rate and the concentration of the mud in a mud pipe on the pipeline is provided for a master control PLC in real time, a low-concentration discharge controller monitors the information of the flow rate and the concentration of the mud in real time, and after the concentration of the mud meets the requirement of loading the cabin, the low-concentration discharge controller controls a gate valve (D011-D014) entering the cabin to be opened and controls the mud to be loaded into the mud cabin; when the concentration of the slurry is lower than the loading requirement or the flow rate is higher than the loading requirement, opening a bypass gate valve (D009-D010) to directly discharge the slurry out of the board;

7) when a loading gate valve, namely a' loading gate valve (D011-D014), is opened and slurry of a dredging pipeline begins to be injected into the cabin, the loading draft control subsystem finishes the time point of dredging;

8) the automatic controller (STAWC) of the harrow arm winch realizes that the harrow arm is folded to a three-pipe flat state of a suction port, and the water is discharged out of the water surface at a set angle, so that the water in the harrow pipe naturally flows out and carries silt which is not washed out of the harrow pipe; after staying for a set time, the harrow tube is upwards retracted to the outboard highest position, then retracted into the inboard, and finally placed on the resting pier.