Underwater vehicle control method based on sub-S-plane controller

Abstract

The invention discloses an underwater vehicle control method based on a sub-S-plane controller. The method comprises the following steps: 1) obtaining the deviation of each degree of freedom of an underwater vehicle as the input of the controller; wherein the degrees of freedom comprise the longitudinal direction, the transverse direction, the vertical direction, the trim direction and the heading direction; 2) constructing a controller based on a sub-S surface; and 3) according to the output of the controller, longitudinal, transverse, vertical, trim and heading control of the underwater vehicle is realized. According to the invention, a classic sigmoid function is replaced by a designed sub-S-type function, so that the control response of the controller is improved, and high-precision motion control is realized.

Description

Technical Field

[0001] The present invention relates to intelligent control technology, and in particular to an underwater vehicle control method based on a sub-S surface controller. Background Art

[0002] Many intelligent equipment and divers are inconvenient to approach the harsh underwater environment, such as wrecked ships and aircraft target detection, dam inspection, submarine optical cable repair, submarine armored cable breakpoint detection, etc. Underwater submersibles have played an increasingly prominent role and have become an important tool for completing underwater operations. Underwater submersibles carry many tasks and need to carry different sensors and actuators according to the task, so good control performance is an important goal of controller design. As a highly nonlinear system with large inertia and strong correlation, the design of the controller of an underwater submersible needs to focus on control quality.

[0003] Conventional S-surface controllers can better meet the control requirements of general underwater submersible operation tasks, but they do not consider the influence of variable static loads, and there is still room for optimization and improvement of the control effect. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an underwater submersible control method based on a sub-S surface controller in view of the defects in the prior art.

[0005] The technical solution adopted by the present invention to solve the technical problem is: an underwater submersible control method based on a sub-S surface controller, comprising the following steps:

[0006] 1) Obtain the deviation of each degree of freedom of the underwater submersible as the input of the controller; the degrees of freedom include: longitudinal, lateral, vertical, pitch, and heading;

[0007] 2) Construct a controller based on the sub-S surface, which is expressed as follows:

[0008]

[0009] Among them, u i is the output signal of the controller; i = 1, 2, 3, 5, 6, representing longitudinal, transverse, vertical, trim, and heading respectively; e i is the input information of the controller, indicating the deviation of the i-th degree of freedom, for e i The rate of change, e i After normalization, k ei for e i The control parameters, for The control parameter, Δu i is the fixed disturbance force within a certain period of time calculated by the adaptive algorithm;

[0010] is the designed sub-S-type function;

[0011] B is the introduced intelligent integral control item;

[0012] f i is the thrust or torque required for the i-th degree of freedom; f max i is the maximum thrust or torque that can be provided by the i-th degree of freedom, To consider the influence of seawater density change on the residual buoyancy, It is a control item that considers the effect of hull compression deformation on the residual buoyancy;

[0013] 3) According to the output of the controller, the longitudinal, lateral, vertical, pitch and bow direction of the underwater submersible are controlled.

[0014] According to the above scheme, the intelligent integral control item B is designed as follows:

[0015]

[0016] in, is the intelligent integral term, that is, when e j (k) is less than the set threshold, an integral term is introduced. j When (k) is greater than the set threshold, the integral term is canceled. This method can effectively solve the integral saturation phenomenon and effectively eliminate the steady-state error of the control; k Ii is the integral adjustment coefficient.

[0017] According to the above scheme, the control term considering the influence of seawater density change on the residual buoyancy The design is as follows,

[0018]

[0019] Where ρ is the density of seawater, in kg / m 3 ; g is the acceleration due to gravity, in N / kg or m / s 2 ; ▽ is the drainage volume, unit is m 3 ; z1 is the current depth value, z0 is the initial depth value, and the unit of depth is m.

[0020] According to the above scheme, the control term considering the influence of the hull compression deformation on the residual buoyancy is The design is as follows,

[0021]

[0022] Where ρ is the density of seawater, in kg / m 3 ; g is the acceleration due to gravity, in N / kg or m / s 2 ; ▽ is the drainage volume, unit is m3 ; z1 is the current depth value, z0 is the initial depth value, the unit of depth is m, α p It is the relative reduction in the volume of the pressure shell when the pressure increases by one unit.

[0023] According to the above scheme, the α p It is expressed as follows:

[0024]

[0025] α p The unit is m 2 / t, where t is 10 3 kg, Z max It is the maximum diving depth of an underwater submersible.

[0026] The beneficial effects produced by the present invention are:

[0027] 1. The present invention adopts the designed sub-S-type function to replace the classic sigmoid function, thereby improving the control response of the controller;

[0028] 2. The present invention eliminates the steady-state error of control by introducing an intelligent integral term;

[0029] 3. The present invention takes into account the adaptive regulation of the residual buoyancy by changes in seawater density and compression deformation of the hull, and can achieve high-precision motion control without human intervention even in the presence of current interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0031] Figure 1 is a method flow chart of an embodiment of the present invention;

[0032] Figure 2 It is a motion control simulation curve diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] like Figure 1 As shown, a method for controlling an underwater vehicle based on a sub-S surface controller comprises the following steps:

[0035] 1) Obtain the target value and measured value deviation of each degree of freedom of the underwater submersible as the input of the controller; the degrees of freedom include: longitudinal, lateral, vertical, pitch, and heading;

[0036] 2) Construct a controller based on the sub-S surface, which is expressed as follows:

[0037]

[0038] Among them, u i is the output signal of the controller; i = 1, 2, 3, 5, 6, representing longitudinal, transverse, vertical, trim, and heading respectively; e i is the input information of the controller, indicating the deviation of the i-th degree of freedom, for e i The rate of change, e i After normalization, k ei for e i The control parameters, for The control parameter, Δu i is the fixed disturbance force within a certain period of time calculated by the adaptive algorithm;

[0039] is the designed sub-S-type function;

[0040] B is the introduced intelligent integral control item;

[0041] f i is the thrust or torque required for the i-th degree of freedom; f max i is the maximum thrust or torque that can be provided by the i-th degree of freedom, To consider the influence of seawater density change on the residual buoyancy, It is a control item that considers the effect of hull compression deformation on the residual buoyancy;

[0042] The design of intelligent integral control item B is as follows:

[0043]

[0044] in, is the intelligent integral term, that is, when e j (k) is less than the set threshold, an integral term is introduced. j When (k) is greater than the set threshold, the integral term is canceled. This method can effectively solve the integral saturation phenomenon and effectively eliminate the steady-state error of the control; k Ii is the integral adjustment coefficient.

[0045] Control term considering the effect of seawater density change on residual buoyancy The design is as follows,

[0046]

[0047] Where ρ is the density of seawater, in kg / m 3; g is the acceleration due to gravity, in N / kg or m / s 2 ; ▽ is the drainage volume, unit is m 3 ; z1 is the current depth value, z0 is the initial depth value, and the unit of depth is m.

[0048] Control term considering the effect of hull compression deformation on residual buoyancy The design is as follows,

[0049]

[0050] Among them, α p It is the relative reduction in the volume of the pressure shell when the pressure increases by one unit.

[0051] α p It is expressed as follows:

[0052]

[0053] α p The unit is m 2 / t, where t is 10 3 kg, Z max It is the maximum diving depth of an underwater submersible.

[0054] 3) According to the output of the controller, the underwater submersible is controlled in the longitudinal, lateral, vertical, pitch and heading directions. After the control solution is solved, the thrust distribution is carried out, and the thrust distribution strategy with heading priority is adopted to distribute the thrust to the actuators of the propeller thruster and rudder joint control.

[0055] The following simulation experiment is carried out using a certain underwater submersible as an example. The underwater submersible is equipped with a propeller thruster, a stern horizontal rudder, a stern vertical rudder, and a bow horizontal rudder. Control is performed according to equations (1) to (5), and the control parameter is selected as k e3 =1.15, k I3 =0.6, k e6 =1.10, k I6 =0.7, Z max =200.

[0056] A digital simulation platform was built, and the underwater submersible was initially set to be stationary at a position of 5 m underwater. There was an ocean current with a velocity of 0.2 m / s and a flow direction of 15°. The underwater submersible position and heading angle control curves in this embodiment are as follows: Figure 2In this embodiment, a method for controlling an underwater submersible based on a novel sub-S-surface controller is applied. The results show that the position and heading angle control are realized. The position and heading angle control of the control method of the present invention has basically no overshoot and oscillation, the depth control accuracy can reach within 0.1m, and the heading control accuracy can reach within 0.15°.

[0057] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A method for controlling an underwater vehicle based on a sub-S surface controller, characterized in that: The following steps are involved: 1) Obtain the deviation of each degree of freedom of the underwater submersible as the input of the controller; the degrees of freedom include: longitudinal, lateral, vertical, pitch, and bow; 2) Construct a controller based on the sub-S surface, which is expressed as follows: Among them, u i is the output signal of the controller; i = 1, 2, 3, 5, 6, representing longitudinal, transverse, vertical, trim, and heading respectively; e i is the input information of the controller, indicating the deviation of the i-th degree of freedom, for e i The rate of change, e i After normalization, k ei for e i The control parameters, for The control parameter, Δu i is the fixed disturbance force within a certain period of time calculated by the adaptive algorithm; is the designed sub-S-type function; B is the introduced intelligent integral control item; f i is the thrust or torque required for the i-th degree of freedom; f maxi is the maximum thrust or torque that can be provided by the i-th degree of freedom, To consider the influence of seawater density change on the residual buoyancy, It is a control item that considers the effect of hull compression deformation on the residual buoyancy; 3) According to the output of the controller, the longitudinal, lateral, vertical, pitch and bow direction of the underwater submersible are controlled.

2. The underwater vehicle control method based on the sub-S surface controller according to claim 1 is characterized in that: The intelligent integral control item B is designed as follows: in, is the intelligent integral term, that is, when e j (k) is less than the set threshold, an integral term is introduced. j When (k) is greater than the set threshold, the integral term is canceled. This method can effectively solve the integral saturation phenomenon and effectively eliminate the steady-state error of the control; k Ii is the integral adjustment coefficient.

3. The underwater vehicle control method based on the sub-S surface controller according to claim 1 is characterized in that: The control term considering the effect of seawater density change on the residual buoyancy The design is as follows, Where, ρ is the density of seawater; g is the acceleration due to gravity; is the drainage volume; z1 is the current depth value, and z0 is the initial depth value.

4. The underwater vehicle control method based on the sub-S surface controller according to claim 1 is characterized in that: The control term considering the effect of hull compression deformation on the residual buoyancy The design is as follows, Where, ρ is the density of seawater; g is the acceleration due to gravity; is the drainage volume; z1 is the current depth value, z0 is the initial depth value, α p It is the relative reduction in the volume of the pressure shell when the pressure increases by one unit.

5. The underwater vehicle control method based on the sub-S surface controller according to claim 4 is characterized in that: The α p It is expressed as follows: α p The unit is m 2 / t, where t is 10 3 kg, Z max It is the maximum diving depth of an underwater submersible.

6. An electronic device, characterized in that: include: one or more processors; as well as a storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors are caused to execute the method according to any one of claims 1 to 5.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

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