Thrust control method, system and equipment for underwater trencher propelling system

Abstract

The invention belongs to the field of underwater trencher control, and particularly relates to a thrust control method, system and equipment of an underwater trencher propelling system.The method comprises the steps that the operation mode of an underwater excavator is obtained, and when the operation mode is manual operation, an operation instruction of an operation handle is obtained, obtaining an input and output relationship between the thrust of the propulsion system and the operation instruction; according to the input and output relation and the thrust distribution matrix, propeller output is obtained; setting a stable speed relationship between the operation instruction and the underwater trencher; obtaining a propeller angle according to the propeller output and stable speed relation; obtaining a control instruction of the propulsion system according to the propeller output and the propeller angle; obtaining a constraint condition of the operation instruction; and obtaining an optimal control instruction of the four propellers according to the constraint conditions and the control instructions. The underwater trencher has the advantages that corresponding actions can be made according to operation instructions of operators, and the response effect of the manually operated underwater trencher is improved when the propeller is saturated.

Description

Technical Field

[0001] The present invention belongs to the field of underwater trenching machine control, and in particular relates to a thrust control method, system and equipment of a propulsion system of an underwater trenching machine. Background Art

[0002] Underwater trenching machine is a heavy-duty working tool used for trenching and burying submarine optical cables and oil and gas pipelines. It has the characteristics of high reliability, high technology and high value. Maneuverability and flow resistance are important indicators to measure the performance of underwater trenching machine. Underwater trenching machine works underwater, and it is very important to be able to accurately control the operation of underwater trenching machine.

[0003] In the related art, the underwater trenching machine is mainly controlled by remote control, and the underwater trenching machine is controlled by a control relationship between a preset remote control command and an output command of the trenching machine.

[0004] Regarding the above-mentioned related technologies, when controlled by remote control, it is impossible to know the maximum value of each type of instruction during manual operation. Therefore, the execution action of the underwater trenching machine is often inconsistent with the given operation instruction, affecting the operation experience and the normal operation of the underwater trenching machine. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a thrust control method, system and equipment for an underwater trencher propulsion system, which can accurately perform corresponding actions according to the operator's instructions in manual control mode, and track the control instruction requirements to the greatest extent in automatic mode while reducing the total power output of the thruster.

[0006] A thrust control method for a propulsion system of an underwater trencher, wherein the underwater trencher comprises four thrusters, including:

[0007] Acquire an operation mode of the underwater excavator, wherein the operation mode includes manual operation and automatic operation;

[0008] When the operation mode is manual operation, obtaining an operation instruction of the operating handle, wherein the operation instruction includes an X-axis direction handle operation instruction, a Y-axis direction handle operation instruction, and a rotation instruction;

[0009] Obtain the input-output relationship between the thrust and operation instructions of the propulsion system;

[0010] According to the input-output relationship and the thrust distribution matrix, the thruster output is obtained;

[0011] Setting the relationship between the handle operation command in the X-axis direction and the handle operation command in the Y-axis direction and the stable speed of the underwater trencher;

[0012] Obtaining a propeller angle according to the propeller output and the stable speed relationship;

[0013] Obtaining a control instruction for a propulsion system according to the propeller output and the propeller angle;

[0014] Obtain constraints for operation instructions;

[0015] According to the constraint conditions and the control instructions, optimal control instructions for the four thrusters are obtained.

[0016] Optionally, the input-output relationship between the thrust of the propulsion system and the operation command is expressed as:

[0017] f X =(f 1 +f 2 +f 3 +f 4 )×cosγ

[0018] f Y =(f 1 -f 2 +f 3 -f 4 )×sinγ

[0019] T R =(f 1 -f 2 -f 3 +f 4 )×(cosγ×c a +sinγ×c b )

[0020] Among them, f X represents the component of the total thrust in the X-axis direction of the robot coordinate system, f Y It represents the component of the total thrust in the Y-axis direction of the robot coordinate system, T R represents the rotational torque generated by the four thrusters on the robot, f 1 、f 2 、f 3 and f 4 They represent the thrust values ​​of the four thrusters, γ is the thruster angle of the thruster, and c a and c b represents the projection distance between the relative position of the four thrusters and the center of the trenching robot on the robot coordinate system, where γ∈[0,90], f x ∈[-f max ,f max ], x=1,2,3,4.

[0021] Optionally, obtaining the thruster output according to the input-output relationship and the thrust distribution matrix includes:

[0022] The thrust distribution matrix is:

[0023]

[0024] in, and Represents the control instructions of the four thrusters, J X Indicates the handle operation instruction in the X-axis direction of the robot coordinate system, J Y Indicates the handle operation instruction in the Y-axis direction of the robot coordinate system, J R Indicates the operation instruction of rotating handle;

[0025] According to the input-output relationship and the thrust distribution matrix, the thruster output is obtained as:

[0026]

[0027] Where k represents the proportionality coefficient between the thrust of the propeller and its command.

[0028] Optionally, the relationship between the handle operation command in the X-axis direction and the handle operation command in the Y-axis direction and the stable speed of the underwater trencher includes:

[0029] The relationship between the handle operation command in the X-axis direction and the handle operation command in the Y-axis direction and the stable speed of the underwater trencher is:

[0030] V X =k1J X

[0031] V Y =k1J Y ;

[0032] Wherein, k1 represents the proportional coefficient between the handle command and the expected speed;

[0033] Under the condition that the handle operation command in the X-axis direction and the handle operation command in the Y-axis direction are in a stable speed relationship with the underwater trencher, the relationship between the trencher water resistance and the operation command is as follows:

[0034] f X =R X

[0035] f Y =R Y ;

[0036]

[0037]

[0038] Among them, R X and R Y are the desired speeds V of the trencher on the X and Y axes respectively X and V Y The corresponding resistance component, C x is the dimensionless drag coefficient, ρ a is the fluid density, A X and A Y is the equivalent cross-sectional area of ​​the trencher in the X-axis and Y-axis directions of the robot coordinate system.

[0039] Optionally, obtaining a propeller angle according to the propeller output and the stable speed relationship includes:

[0040] Substituting the stable speed relationship into the thruster output to obtain the thruster angle;

[0041] The thruster angle is expressed as:

[0042]

[0043] Among them, A X and A Y is the equivalent cross-sectional area of ​​the trencher in the X-axis and Y-axis directions of the robot coordinate system, J X Indicates the handle operation instruction in the X-axis direction of the robot coordinate system, J Y Indicates the handle operation instruction in the Y-axis direction of the robot coordinate system.

[0044] Optionally, the constraint conditions and the control instructions to obtain the optimal control instructions for the four thrusters include:

[0045] The constraints are:

[0046]

[0047] The control instructions of the propulsion system are expressed as:

[0048]

[0049] in, as well as is the optimal thruster allocation value obtained by solving the optimization problem, γ * is the optimal thruster angle rotation value obtained by solving the above optimization problem;

[0050] The control instructions of the propulsion system are solved according to the constraints to obtain the optimal control instructions of the four thrusters.

[0051] Optionally, when the operation mode is an automatic mode, a control instruction of a positioning controller is obtained, and the positioning controller is used to issue an instruction to control the movement of the underwater trenching machine;

[0052] Obtaining a control requirement, wherein the control requirement is to track the control instruction to the maximum extent and minimize the total power output of the thruster;

[0053] According to the control requirements, the association relationship between the control instructions and the output instructions is obtained, and the association relationship is expressed as:

[0054]

[0055] Among them, J2 is the evaluation index of the thruster allocation strategy in the automatic control mode of the trencher, and f CmdX 、f CmdY 、T CmdR Output control instructions for ROV motion control system;

[0056] Set automatic constraints for automatic control;

[0057] According to the automatic constraint conditions and the association relationship, optimal control instructions for the four thrusters are obtained.

[0058] A thrust control system for an underwater trenching machine propulsion system, comprising:

[0059] A first acquisition module is used to acquire an operation mode of the underwater excavator, wherein the operation mode includes manual operation and automatic operation;

[0060] A selection module, for obtaining an operation instruction of an operating handle when the operation mode is manual operation, wherein the operation instruction includes an X-axis handle operation instruction, a Y-axis handle operation instruction, and a rotation instruction;

[0061] A second acquisition module is used to acquire the input-output relationship between the thrust of the propulsion system and the operation instruction;

[0062] A first calculation module, used for obtaining a thruster output according to the input-output relationship and the thrust distribution matrix;

[0063] A setting module, used to set the relationship between the handle operation command in the X-axis direction and the handle operation command in the Y-axis direction and the stable speed of the underwater trencher;

[0064] A second calculation module, used for obtaining a propeller angle according to the propeller output and the stable speed relationship;

[0065] A third calculation module, used for obtaining a control instruction of a propulsion system according to the propeller output and the propeller angle;

[0066] A constraint module, used to obtain constraint conditions of operation instructions;

[0067] A control module is used to obtain the optimal control instructions of the four thrusters according to the constraints and the control instructions.

[0068] A terminal device comprises a memory and a processor. The memory stores a computer program that can be run on the processor. When the processor loads and executes the computer program, a thrust control method for a propulsion system of an underwater trencher is adopted.

[0069] A computer-readable storage medium stores a computer program. When the computer program is loaded and executed by a processor, a thrust control method for a propulsion system of an underwater trencher is adopted.

[0070] The beneficial effects of the present invention are:

[0071] 1. In the manual operation mode, considering that the operation instructions given by the operator may exceed the value range of the control instructions, the original control method is improved. First, the input-output relationship between the thrust of the propulsion system and the operation instructions is obtained, and then the thrust distribution matrix is ​​used to obtain the thruster output. In order to achieve the relationship between the stable operation instructions and the stable speed, the stable speed relationship is set, and the stable speed relationship is combined with the thruster output to obtain the expression of the thruster angle. Combined with the thruster output, the control instructions of the propulsion system can be obtained. According to the set constraints, the control instructions are solved to obtain the optimal control instructions for the four thrusters. Compared with the traditional control method, the present application can make corresponding actions according to the operator's operation instructions, which improves the response effect of the manually operated underwater trencher when the thruster is saturated.

[0072] 2. In automatic mode, according to the control instructions given by the positioner, the relationship between the control instructions and the output instructions is designed to track the control instructions to the maximum extent and minimize the total power output of the thruster, and the optimal control instructions are obtained by combining the constraints. The thruster is allowed to track the controller output instructions as much as possible, and the overall power of the thruster is reduced by reasonably allocating the thruster output and adjusting the thruster angle when the thruster is not in the saturated state, thereby improving the maneuverability of the underwater robot and its ability to adapt to complex sea conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 It is a structural schematic diagram of the underwater trenching machine of the present invention;

[0074] Figure 2 It is a schematic diagram of the structure of a single propeller of the underwater trenching machine of the present invention;

[0075] Figure 3It is a flow chart of a thrust control method of a propulsion system of an underwater trencher according to the present invention;

[0076] Figure 4 This is the motion control flow chart for the underwater trencher when it is manually operated;

[0077] Figure 5 This is the motion control flow chart for the automatic operation of the underwater trencher.

[0078] Description of reference numerals:

[0079] 1. Trench digger body; 2. Thruster; 3. Telescopic rod; 4. Fixed rod. DETAILED DESCRIPTION

[0080] like Figure 1 As shown, the structure of the underwater trencher adopted in the present application is as follows, including a trencher body and four thrusters, a telescopic rod and a fixed rod, one end of the thruster is rotatably connected to the telescopic rod, and the other end of the telescopic rod is rotatably connected to the fixed rod. The trencher body is rectangular, and the four thrusters are respectively arranged at the four corners of the trencher body. The fixed rod and the telescopic rod are both arranged on the trencher body, and a fixed rod and a telescopic rod are provided on one corner of the trencher.

[0081] With the center of gravity of the ROV as the origin, define the body coordinate system, where the X-axis direction is the forward direction of the ROV, the Y-axis points to the right direction of the ROV, and the thruster rotation axis is the origin, defined as follows Figure 2 The thruster coordinate system is shown.

[0082] In order to calculate the relative angle between the thrust direction of the thruster and the ROV body, the thruster angle is defined as the rotation angle of the thruster X axis in the ROV coordinate system and the ROV coordinate system X. Right rotation is defined as positive rotation, and left rotation is defined as negative rotation. According to the above definition, the thruster rotation angle is calculated as follows:

[0083]

[0084] Among them, γ1 is the angle between the line connecting the C point of the propeller base axis and the B point of the cylinder axis and the ROV coordinate system Y as shown in the figure, and α2 is the angle between the CA line and the X1 axis of the propeller coordinate system; after the propeller is installed, the angles α1 and α2 are usually fixed values, which are related to the relative installation positions of the propeller and its cylinder; β 1 It is the angle between the CA line and the CB line, which can be calculated based on the triangular cosine formula. After the thruster is installed, it is only related to the length of the cylinder, that is, the AB length as shown in the figure.

[0085]

[0086] In order to distinguish different thrusters later, the above symbols are redefined:

[0087] Where x = 1, 2, 3, 4, representing the four thrusters installed on the ROV.

[0088] Therefore, the total thrust and torque acting on the ROV are expressed as follows:

[0089] f X =f 1 ×cosγ 1 +f 2 ×cosγ 2 +f 3 ×cosγ 3 +f 4 ×cosγ 4

[0090] f Y =f 1 ×sinγ 1 -f 2 ×sinγ 2 +f 3 ×sinγ 3 -f 4 ×sinγ 4

[0091] T R =f 1 ×cosγ 1 ×c1-f 2 ×cosγ 2 ×c2-f 3 ×cosγ 3 ×c3+f 4 ×cosγ 4 ×c4+f 1 ×sinγ 1 ×c5-f 2 ×sinγ 2 ×c6-f 3 ×sinγ 3 ×c7+f 4 ×sinγ 4 ×c8 (3)

[0092] where f X represents the component of the total thrust in the X-axis direction of the robot coordinate system; f Y represents the component of the total thrust in the Y-axis direction of the robot coordinate system; f 1 、f 2 、f 3 and f 4 Respectively represent the thrust values ​​of pushers 1, 2, 3, and 4; γ1 , γ 2 , γ 3 and γ 4 Respectively represent the rotation angles of the coordinate axes X1, X2, X3 and X4 corresponding to the pushers 1, 2, 3 and 4 and the X axis of the robot coordinate system, that is, the pusher angle; T R represents the rotational torque generated by the four thrusters on the robot; c1 and c2 represent the projection distance of the relative position relationship between the position of thruster 1 and the center of the trenching robot on the robot coordinate system; c3 and c4 represent the projection distance of the relative position relationship between the position of thruster 2 and the center of the trenching robot on the robot coordinate system; c5 and c6 represent the projection distance of the relative position relationship between the position of thruster 3 and the center of the trenching robot on the robot coordinate system; c7 and c8 represent the projection distance of the relative position relationship between the position of thruster 4 and the center of the trenching robot on the robot coordinate system. Usually, the thrusters are arranged symmetrically. In order to simplify the subsequent derivation, let c1 = c3 = c5 = c7 = c a and c2=c4=c6=c8=c b , where c a and c b represents the projection distance between the relative position of thrusters 1, 2, 3, 4 and the center of the trenching robot on the robot coordinate system, and let γ 1 =γ 2 =γ 3 =γ 4 =γ, where γ represents the rotation angle of the coordinate axes X1, X2, X3 and X4 of the thrusters 1, 2, 3, 4 and the X axis of the robot coordinate system. Therefore, the above equation can be simplified as follows:

[0093] f X =(f 1 +f 2 +f 3 +f 4 )×cosγ

[0094] f Y =(f 1 -f 2 +f 3 -f 4 )×sinγ

[0095] T R =(f 1 -f 2 -f 3 +f 4 )×(cosγ×c a +sinγ×c b )

[0096] where γ∈[0,90], fx ∈[-f max ,f max ], x=1,2,3,4.

[0097] Here, the thruster force and the range of thruster output are normalized, that is, f max =1, and it is assumed that the actual force of the propeller and its command maintain a strict linear relationship. Therefore, in the present invention, f x It indicates the force of the thruster, or the command size of the thruster.

[0098] like Figure 3 As shown, a thrust control method of a propulsion system of an underwater trencher, the underwater trencher includes four thrusters, including:

[0099] S1. Obtaining an operation mode of the underwater excavator, where the operation mode includes manual operation and automatic operation.

[0100] S2. When the operation mode is manual operation, obtain the operation instructions of the operation handle, the operation instructions include the handle operation instructions in the X-axis direction, the handle operation instructions in the Y-axis direction and the rotation instructions.

[0101] Specifically, the trencher operator gives the trencher motion instructions in three degrees of freedom by operating the three-axis free operation handle, where J X Indicates the handle operation instruction in the X-axis direction of the robot coordinate system, J Y Indicates the handle operation instruction in the Y-axis direction of the robot coordinate system, J R Indicates the operation command of the rotary handle. The thrust distribution controller in manual operation mode generates the control commands required by the four thrusters online according to the handle input, where and Respectively represent the control instructions corresponding to thrusters 1, 2, 3, and 4, λ cmd It indicates the rotation angle instruction of all thrusters. After receiving the thruster control instruction, the thrusters and their control systems output the thrust of each thruster and change the thruster angle, acting on the underwater trenching robot, thereby changing the speed, position and angle of the trenching robot.

[0102] Set the following conditions:

[0103] (1) Handle freedom command J X , J Y , J R The value range is between -1 and 1, that is, -1 represents the maximum value in the reverse direction, and 1 represents the maximum value in the positive direction;

[0104] (2) Each thruster has the same output performance, including the same maximum reverse thrust and maximum forward thrust;

[0105] (3) The maximum positive thrust and the maximum negative thrust of each thruster are the same, both are f max ;

[0106] (4) Under the action of the thruster control system, each thruster can accurately respond to the corresponding thruster output, and the response process of the thruster control system is ignored, that is, it is assumed that the thrust and angle of the thruster can immediately respond to the corresponding control command;

[0107] (5) Under the control of each thruster control system, when and When they are -1 respectively, the corresponding thrusters output the maximum reverse force. and When it is 1, it corresponds to the maximum positive force output by each thruster, and the thruster output and the thruster stable output force are in a simple linear relationship, that is, when when when when Where k represents the proportionality coefficient between the thrust of the propeller and its command, which is determined by the physical characteristics of the propeller itself.

[0108] S3. Obtain the input-output relationship between the thrust of the propulsion system and the operation command.

[0109] The input-output relationship between the thrust of the propulsion system and the operating instructions is expressed as:

[0110] f X =(f 1 +f 2 +f 3 +f 4 )×cosγ

[0111] f Y =(f 1 -f 2 +f 3 -f 4 )×sinγ

[0112] T R =(f 1 -f 2 -f 3 +f 4 )×(cosγ×c a +sinγ×c b )

[0113] Among them, f X represents the component of the total thrust in the X-axis direction of the robot coordinate system, f Y represents the component of the total thrust in the Y-axis direction of the robot coordinate system; f 1 、f2 、f 3 and f 4 They represent the thrust values ​​of the four thrusters, γ is the thruster angle of the thruster, and c a and c b represents the projection distance between the relative position of the four thrusters and the center of the trenching robot on the robot coordinate system, where γ∈[0,90], f x ∈[-f max ,f max ], x=1,2,3,4.

[0114] S4. Obtain the thruster output according to the input-output relationship and the thrust distribution matrix.

[0115] Specifically, the thrust distribution matrix is:

[0116]

[0117] in, and Represents the control instructions of the four thrusters, J X Indicates the handle operation instruction in the X-axis direction of the robot coordinate system, J Y Indicates the handle operation instruction in the Y-axis direction of the robot coordinate system, J R Indicates the operation instruction of rotating handle;

[0118] when and When the result is between -1 and 1, that is, each thruster does not have output saturation, according to the above assumptions, the relationship between the handle command and thrust can be obtained:

[0119]

[0120] Among them, k represents the proportional coefficient between the thrust of the thruster and its command, which is determined by the physical characteristics of the thruster itself.

[0121] According to the input-output relationship and the thrust distribution matrix, the thruster output is obtained as:

[0122] The input-output relationship is expressed as a matrix form of the input-output relationship:

[0123]

[0124] Substituting the thrust distribution matrix into the matrix form of the input-output relationship, we get:

[0125]

[0126] Simplifying it, we get:

[0127]

[0128] Where k represents the proportionality coefficient between the thrust of the propeller and its command.

[0129] S5. Setting the relationship between the handle operation command in the X-axis direction and the handle operation command in the Y-axis direction and the stable speed of the underwater trencher.

[0130] Specifically, in order to improve the manual operation of underwater robots, J X and J Y The handle command shows a linear relationship with the stable speed of the trencher on the X and Y axes:

[0131] V X =k1J X

[0132] V Y =k1J Y

[0133] Among them, V X and V Y Indicates that the trencher is in J X and J Y The expected speed on the X-axis and Y-axis under the handle command, k1 represents the proportional coefficient between the handle command and the expected speed.

[0134] In order to satisfy the linear relationship, the corresponding water resistance and thruster force need to be equal:

[0135] f X =R X

[0136] f Y =R Y

[0137] The calculation formula of trencher water resistance is as follows:

[0138]

[0139]

[0140] Where R X and R Y are the desired speeds V of the trencher on the X and Y axes respectively X and V Y The corresponding resistance component, C x is the dimensionless drag coefficient, ρ a is the fluid density, A X and A Y It is the equivalent cross-sectional area of ​​the trencher in the X-axis and Y-axis directions of the robot coordinate system. The corresponding numerical value is determined by the outer structure design of the trencher.

[0141] S6. Obtain the thruster angle according to the thruster output and the stable speed relationship.

[0142] Specifically, in order to achieve the operation effect of stable speed, the desired propeller angle needs to be calculated. Therefore, according to the linear relationship, the equality of water resistance and propeller force, the calculation formula of trencher water resistance and propeller output, the desired propeller angle γ is obtained. exp Calculation formula:

[0143]

[0144]

[0145] Simplifying the calculation formula, we get the following expected thruster angle when all thrusters are unsaturated:

[0146]

[0147] S7. Obtain control instructions for the propulsion system according to the propeller output and the propeller angle.

[0148] Specifically, therefore, when the handle command is small and the thruster angle meets the expected thruster angle, the thruster force calculated by the thrust distribution matrix does not exceed its maximum and minimum value range, that is, no thruster enters the output saturation state, and the expression of the thruster output, the trenching machine operation command and force formula represented by the handle command J can accurately represent the force condition of the trenching machine. X , J Y and trencher movement speed V X and V Y It shows a good linear relationship, and the handle instructions given by the operator can better act on the movement of the trencher, thereby meeting the operator's operating needs for the trencher.

[0149] However, when the operator gives the joystick command J X , J Y , J R When it is large, the single control command calculated according to the thrust distribution matrix of equation and It may exceed the range of -1 to 1, and the corresponding thruster output is likely to exceed its maximum working capacity, so it cannot represent the correspondence between the actual handle command and the trencher force. In this case, the operator will feel that the trencher is out of control.

[0150] In order to solve the problem of propeller saturation and improve the operating experience of trenching machine operators, the expression of propeller output obtained when the propeller is assumed to be unsaturated is used as the expected trenching machine propulsion effect, and the following optimal control index expression is obtained:

[0151]

[0152] S8. Obtain constraints of the operation instruction.

[0153] Specifically, the constraints include the desired thruster angle of the thruster, the thruster angle rotation value range, and the value range of each instruction, which are expressed as follows:

[0154]

[0155]

[0156] in, is the optimal thruster allocation value obtained by solving the optimization problem, γ * is the optimal thruster angle rotation value obtained by solving the above optimization problem.

[0157] At this time, no matter what the operating instructions given by the operator are, the underwater trencher can make corresponding actions in time to improve the operator's operating experience. Figure 4 This is the motion control flow chart for manual operation.

[0158] S9. Obtain the optimal control instructions for the four thrusters based on the constraints and control instructions.

[0159] When the operation mode is the automatic mode, a control instruction of the positioning controller is obtained, and the positioning controller is used to issue an instruction to control the action of the underwater trenching machine.

[0160] Obtain control requirements, which are to track control instructions to the maximum extent and minimize the total power output of the thruster.

[0161] Specifically, when the underwater trencher is in automatic control mode, such as automatic positioning control mode, the thruster command does not come from the driver's operating handle, but from the command output by the ROV positioning controller. Unlike manual operation that takes the operator's feelings into consideration, in the trencher automatic control mode, the purpose of the optimal thrust distribution strategy is to track the control command requirements to the greatest extent while reducing the total power output of the thruster. Minimizing the total power output of the thruster is expressed by minimizing the sum of the squares of the control commands.

[0162] According to the control requirements, the correlation between the control instructions and the output instructions is obtained, and the correlation is expressed as:

[0163]

[0164] Among them, J2 is the evaluation index of the thruster allocation strategy in the automatic control mode of the trencher, and f CmdX 、fCmdY , T CmdR It is the control command output by ROV motion control system.

[0165] Set automatic constraints for automatic control.

[0166] Specifically, the automatic constraints are:

[0167]

[0168]

[0169] Among them, f CmdX 、f CmdY , T CmdR It is the control command output by ROV motion control system.

[0170] According to the automatic constraints and the correlation, the optimal control instructions of the four thrusters are obtained. The overall motion control process of the automatic control is as follows: Figure 5 shown.

[0171] In order to verify the effectiveness of this method, it is assumed that f CmdX is 0.5, f CmdY =0.1, T CmdR is 0, because the corresponding control instruction demand is not very large, so it can be judged that the thruster has sufficient tracking capability, so the above optimization equation must be able to satisfy:

[0172]

[0173] That is, the actual output is consistent with the instruction requirements, so:

[0174]

[0175] After simplifying the derivation, we get:

[0176]

[0177] Substituting equation (1) and equation (3) into the automatic constraints of the optimization equation, we can obtain the following optimization index expression:

[0178]

[0179] Under the premise of satisfying the automatic constraints of the optimization equation, the minimum value of the index function of equation (4) is obtained:

[0180] γ=24.0948°

[0181] f 4 =0.0757

[0182] f1 =0.1982

[0183] f 2 =0.0757

[0184] f 3 =0.1982

[0185] If the thruster angle is kept constant and assumed to be 45°, the optimal output of each thruster obtained according to the traditional thrust control allocation method is:

[0186] γ=0.7854(=45°)

[0187] f 4 =0.1414

[0188] f 1 =0.2121

[0189] f 2 =0.2121

[0190] f 3 =0.1414

[0191] Obviously, it is greater than the propulsion power required when the thruster angle is adjusted to the optimal angle.

[0192] A thrust control system for an underwater trenching machine propulsion system, comprising:

[0193] A first acquisition module is used to acquire an operation mode of the underwater excavator, where the operation mode includes manual operation and automatic operation;

[0194] A selection module is used to obtain the operation instructions of the operating handle when the operation mode is manual operation, and the operation instructions include the handle operation instructions in the X-axis direction, the handle operation instructions in the Y-axis direction, and the rotation instructions;

[0195] A second acquisition module is used to acquire the input-output relationship between the thrust of the propulsion system and the operation instruction;

[0196] A first calculation module is used to obtain the thruster output according to the input-output relationship and the thrust distribution matrix;

[0197] A setting module, used to set the relationship between the handle operation command in the X-axis direction and the handle operation command in the Y-axis direction and the stable speed of the underwater trencher;

[0198] The second calculation module is used to obtain the propeller angle according to the propeller output and the stable speed relationship;

[0199] A third calculation module is used to obtain a control instruction of the propulsion system according to the propeller output and the propeller angle;

[0200] A constraint module, used to obtain constraint conditions of operation instructions;

[0201] The control module is used to obtain the optimal control instructions for the four thrusters based on the constraints and control instructions.

[0202] A terminal device comprises a memory and a processor. The memory stores a computer program that can be run on the processor. When the processor loads and executes the computer program, a thrust control method for a propulsion system of an underwater trencher is adopted.

[0203] A computer-readable storage medium stores a computer program. When the computer program is loaded and executed by a processor, a thrust control method for a propulsion system of an underwater trencher is adopted.

[0204] An embodiment of the present application also discloses a terminal device, including a memory and a processor. The memory stores a computer program that can be run on the processor. When the processor loads and executes the computer program, a thrust control method for an underwater trencher propulsion system is adopted.

[0205] The terminal device may be a computer device such as a desktop computer, a laptop computer or a cloud server, and the terminal device includes but is not limited to a processor and a memory. For example, the terminal device may also include input and output devices, a network access device and a bus.

[0206] Among them, the processor can adopt a central processing unit (CPU). Of course, according to actual usage, other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. can also be adopted. The general-purpose processor can adopt a microprocessor or any conventional processor, etc., and this application does not impose any restrictions on this.

[0207] Among them, the memory can be an internal storage unit of the terminal device, such as a hard disk or memory of the terminal device, or it can be an external storage device of the terminal device, such as a plug-in hard disk, a smart memory card (SMC), a secure digital card (SD) or a flash memory card (FC) equipped on the terminal device, etc., and the memory can also be a combination of an internal storage unit and an external storage device of the terminal device. The memory is used to store computer programs and other programs and data required by the terminal device. The memory can also be used to temporarily store data that has been output or is to be output, and this application does not impose any restrictions on this.

[0208] Among them, through this terminal device, a thrust control method of an underwater trencher propulsion system in the above embodiment is stored in the memory of the terminal device, and is loaded and executed on the processor of the terminal device for easy use.

[0209] An embodiment of the present application further discloses a computer-readable storage medium, and the computer-readable storage medium stores a computer program, wherein when the computer program is executed by a processor, a thrust control method for an underwater trencher propulsion system in the above embodiment is adopted.

[0210] Among them, the computer program can be stored in a computer-readable medium, the computer program includes computer program code, the computer program code can be in the form of source code, object code, executable file or certain middleware, etc. The computer-readable medium includes any entity or device that can carry the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the computer-readable medium includes but is not limited to the above-mentioned components.

[0211] Among them, through this computer-readable storage medium, a thrust control method of an underwater trencher propulsion system in the above embodiment is stored in a computer-readable storage medium, and is loaded and executed on a processor to facilitate the storage and application of the above method.

[0212] A person skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of protection of the present application is limited to these examples. In line with the concept of the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of different aspects of one or more embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0213] One or more embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the present application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of the present application should be included in the protection scope of the present application.

Claims

1. A method for controlling thrust of a propulsion system of an underwater trencher, wherein the underwater trencher comprises four thrusters, wherein: include: Acquire an operation mode of the underwater excavator, wherein the operation mode includes manual operation and automatic operation; When the operation mode is manual operation, obtaining an operation instruction of the operating handle, wherein the operation instruction includes an X-axis direction handle operation instruction, a Y-axis direction handle operation instruction, and a rotation instruction; Obtain the input-output relationship between the thrust and operation instructions of the propulsion system; According to the input-output relationship and the thrust distribution matrix, the thruster output is obtained; Setting the relationship between the handle operation command in the X-axis direction and the handle operation command in the Y-axis direction and the stable speed of the underwater trencher; Obtaining a propeller angle according to the propeller output and the stable speed relationship; Obtaining a control instruction for a propulsion system according to the propeller output and the propeller angle; Obtain constraints for operation instructions; According to the constraint conditions and the control instructions, optimal control instructions for the four thrusters are obtained.

2. The thrust control method of the underwater trenching machine propulsion system according to claim 1, characterized in that: The input-output relationship between the thrust of the propulsion system and the operating instructions is expressed as: f X =(f 1 +f 2 +f 3 +f 4 )×cosγ f Y =(f 1 -f 2 +f 3 -f 4 )×sinγ T R =(f 1 -f 2 -f 3 +f 4 )×(cosγ×c a +sinγ×c b ) Among them, f X represents the component of the total thrust in the X-axis direction of the robot coordinate system, f Y It represents the component of the total thrust in the Y-axis direction of the robot coordinate system, T R represents the rotational torque generated by the four thrusters on the robot, f 1 、f 2 、f 3 and f 4 They represent the thrust values ​​of the four thrusters, γ is the thruster angle of the thruster, and c a and c b represents the projection distance between the relative position of the four thrusters and the center of the trenching robot on the robot coordinate system, where γ∈[0,90], f x ∈[-f max ,f max ], x=1,2,3,4.

3. The thrust control method of the underwater trenching machine propulsion system according to claim 2, characterized in that: The obtaining of the thruster output according to the input-output relationship and the thrust distribution matrix comprises: The thrust distribution matrix is: in, and Represents the control instructions of the four thrusters, J X Indicates the handle operation instruction in the X-axis direction of the robot coordinate system, J Y Indicates the handle operation instruction in the Y-axis direction of the robot coordinate system, J R Indicates the operation instruction of rotating handle; According to the input-output relationship and the thrust distribution matrix, the thruster output is obtained as: Where k represents the proportionality coefficient between the thrust of the propeller and its command.

4. The thrust control method of the underwater trenching machine propulsion system according to claim 1, characterized in that: The relationship between the handle operation command in the X-axis direction and the handle operation command in the Y-axis direction and the stable speed of the underwater trencher includes: The relationship between the handle operation command in the X-axis direction and the handle operation command in the Y-axis direction and the stable speed of the underwater trencher is: In X =k1J X In Y =k1J Y ; Wherein, k1 represents the proportional coefficient between the handle command and the expected speed; Under the condition that the handle operation command in the X-axis direction and the handle operation command in the Y-axis direction are in a stable speed relationship with the underwater trencher, the relationship between the trencher water resistance and the operation command is as follows: f X =R X f Y =R Y ; Among them, R X and R Y are the desired speeds V of the trencher on the X and Y axes respectively X and V Y The corresponding resistance component, C x is the dimensionless drag coefficient, ρ a is the fluid density, A X and A Y is the equivalent cross-sectional area of ​​the trencher in the X-axis and Y-axis directions of the robot coordinate system.

5. The thrust control method of the underwater trenching machine propulsion system according to claim 4, characterized in that: The obtaining of the propeller angle according to the propeller output and the stable speed relationship comprises: Substituting the stable speed relationship into the thruster output to obtain the thruster angle; The thruster angle is expressed as: Among them, A X and A Y is the equivalent cross-sectional area of ​​the trencher in the X-axis and Y-axis directions of the robot coordinate system, J X Indicates the handle operation instruction in the X-axis direction of the robot coordinate system, J Y Indicates the handle operation instruction in the Y-axis direction of the robot coordinate system.

6. The thrust control method of the underwater trenching machine propulsion system according to claim 5, characterized in that: The constraints and the control instructions to obtain the optimal control instructions for the four thrusters include: The constraints are: The control instructions of the propulsion system are expressed as: in, as well as is the optimal thruster allocation value obtained by solving the optimization problem, γ * is the optimal thruster angle rotation value obtained by solving the above optimization problem; The control instructions of the propulsion system are solved according to the constraints to obtain the optimal control instructions of the four thrusters.

7. The thrust control method of the underwater trenching machine propulsion system according to claim 1, characterized in that it comprises: When the operation mode is the automatic mode, obtaining a control instruction of a positioning controller, wherein the positioning controller is used to issue an instruction to control the movement of the underwater trenching machine; Obtaining a control requirement, wherein the control requirement is to track the control instruction to the maximum extent and minimize the total power output of the thruster; According to the control requirements, the association relationship between the control instructions and the output instructions is obtained, and the association relationship is expressed as: Among them, J2 is the evaluation index of the thruster allocation strategy in the automatic control mode of the trencher, and f CmdX 、f CmdY 、T CmdR Output control instructions for ROV motion control system; Set automatic constraints for automatic control; According to the automatic constraint conditions and the association relationship, optimal control instructions for the four thrusters are obtained.

8. A thrust control system for an underwater trenching machine propulsion system, characterized in that: include: A first acquisition module is used to acquire an operation mode of the underwater excavator, wherein the operation mode includes manual operation and automatic operation; A selection module, for obtaining an operation instruction of an operating handle when the operation mode is manual operation, wherein the operation instruction includes an X-axis handle operation instruction, a Y-axis handle operation instruction, and a rotation instruction; A second acquisition module is used to acquire the input-output relationship between the thrust of the propulsion system and the operation instruction; A first calculation module, used for obtaining a thruster output according to the input-output relationship and the thrust distribution matrix; A setting module, used to set the relationship between the handle operation command in the X-axis direction and the handle operation command in the Y-axis direction and the stable speed of the underwater trencher; A second calculation module, used for obtaining a propeller angle according to the propeller output and the stable speed relationship; A third calculation module, used for obtaining a control instruction of a propulsion system according to the propeller output and the propeller angle; A constraint module, used to obtain constraint conditions of operation instructions; The control module is used to obtain the optimal control instructions for the four thrusters according to the constraint conditions and the control instructions.

9. A terminal device, comprising a memory and a processor, characterized in that: The memory stores a computer program that can be run on the processor, and when the processor loads and executes the computer program, the method according to any one of claims 1 to 7 is adopted.

10. A computer-readable storage medium having a computer program stored therein, characterized in that: When the computer program is loaded and executed by a processor, the method according to any one of claims 1 to 7 is adopted.

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