Control system and method of marine underwater monitoring robot

Abstract

The invention relates to a control system and method for a marine underwater monitoring robot, and the system comprises a main control module which carries out the compression and coding of collected operation environment data and motion posture data according to a video data compression protocol, compressed and coded operation environment data and motion attitude data are sent to a control center through a wireless communication module, the control center feeds attitude control information back to a main control module according to requirements, and the main control module controls the motion state of the robot through a motion control module after receiving the attitude control information; the environment information acquisition module is used for acquiring a video signal, turbidity and temperature of a working environment; the attitude information acquisition module is used for acquiring collision sonar, pressure, depth and motion state information of the current robot; a wireless communication module; and the motion control module controls the robot to operate according to the expected posture. The system can realize depth-keeping control and attitude control, and the motion control capability is relatively ideal.

Description

Technical Field

[0001] The present application relates to the field of underwater monitoring robot monitoring technology, and in particular to a control system and method for a ship underwater monitoring robot. Background Art

[0002] Since the underwater operating environment of ships is characterized by dark light, fast water flow and narrow operating space, underwater monitoring of ships has a decisive impact on ocean exploration, navigation safety and equipment maintenance. Therefore, monitoring of the underwater operating environment of ships plays an important role in marine economy and ecological balance.

[0003] However, the current mainstream underwater monitoring robots in China are often affected by the accuracy of the environment and motion posture sensors and the complexity of the control algorithm, which often leads to unsatisfactory detection effects. In addition, due to the large number of obstacles, fast water flow, and operation in a small space, this also leads to excessive manual intervention, greater difficulty in operation, and an increased possibility of failure. In addition, since most of them only support short-distance communication, their anti-interference capabilities are relatively weak, and it is difficult to ensure the quality of transmitted data. Summary of the invention

[0004] Based on this, it is necessary to propose a control system and method for a ship underwater monitoring robot in view of the problem that the detection effect of the ship underwater monitoring robot in the prior art is not ideal.

[0005] In order to achieve the above-mentioned purpose, the embodiment of the present application provides a control system of a ship underwater monitoring robot, comprising the following steps:

[0006] A main control module, which compresses and encodes the collected working environment data and motion posture data according to the video data compression protocol, and then sends the compressed and encoded working environment data and motion posture data to the control center through the wireless communication module. The control center feeds back the posture control information to the main control module according to the demand. After receiving the posture control information, the main control module controls the motion state of the robot through the motion control module;

[0007] An environmental information acquisition module, which is used to collect video signals, turbidity and temperature of the working environment;

[0008] A posture information collection module, which is used to collect collision sonar, pressure, depth and motion state information of the current robot;

[0009] A wireless communication module, which is used to compress and encode the collected working environment data and motion posture data and send them to the control center;

[0010] The motion control module controls the robot to run in a desired posture after receiving the posture control information fed back by the control center.

[0011] Preferably, the main control module includes an STM32MP1 microprocessor and a TMS320C6472 microprocessor;

[0012] The STM32MP1 microprocessor is used to drive the environment information acquisition module and the posture information acquisition module;

[0013] The TMS320C6472 microprocessor is used to compress and encode the collected working environment data and motion posture data according to the video data compression protocol, and receive the posture control information fed back by the control center.

[0014] Preferably, the environmental information acquisition module includes an LED lamp, a temperature sensor, a turbidity sensor and a video acquisition sensor.

[0015] Preferably, the posture information acquisition module includes a motion posture sensor, a depth sensor, a pressure sensor and a sonar sensor;

[0016] The motion posture sensor adopts a nine-axis motion sensor of model MPU9250, and the nine-axis motion sensor includes a three-axis magnetometer, a three-axis gyroscope, a three-axis accelerometer and a DMP dynamic motion processor.

[0017] Preferably, the motion control module includes a motion device and a control module, the motion control is achieved by a servo motor, and the control method of the motion control module includes an open-loop control method and a closed-loop control method. The open-loop control method is used to control the motion of the robot, and the closed-loop control method is used to provide feedback on the motion posture of the robot.

[0018] The present application also provides a control method for a marine underwater monitoring robot, which comprises the following steps:

[0019] The STM32MP1 microprocessor is used to drive the environmental information acquisition module and the attitude information acquisition module, turn on the LED light, and complete the data acquisition of temperature, turbidity, video signal, collision sonar, pressure, depth, and motion status;

[0020] The collected data of temperature, turbidity, video signal, collision sonar, pressure, depth, and motion status are compressed and encoded according to the video data compression protocol;

[0021] Send compressed and encoded data of temperature, turbidity, video signal, collision sonar, pressure, depth, and motion status to the control center through the wireless communication module;

[0022] The control center feeds back the posture control information to the main control module according to the demand. After receiving the posture control information, the main control module controls the motion state of the robot through the motion control module.

[0023] Preferably, the control center feeds back the posture control information to the main control module according to the demand, and after receiving the posture control information, the main control module controls the motion state of the robot through the motion control module, including:

[0024] In the inertial coordinate system, the robot's position is represented by coordinates (x0, y0, z0), and the robot's attitude angle is represented by (φ, θ, ψ). θ, ψ represent the roll angle, pitch angle, and heading angle, respectively. In the carrier coordinate system, (p, q, r) and (u, v, w) are used to represent the angular velocity and linear velocity of the robot. The following formula is the robot kinematic transformation equation:

[0025]

[0026] In formula (1), the robot position and angle in the inertial coordinate system are The linear velocity and angular velocity of the robot in the carrier coordinate system are V = [u0, v0, w0, p, q, r] T , the pose conversion matrix between the carrier coordinate system and the inertial coordinate system is represented by J(η);

[0027] The position and angle variables in the inertial coordinate system and the angular velocity and linear velocity variables in the carrier coordinate system have the following relationship:

[0028]

[0029] Assume that the expected trajectory given in advance is η d =[x 0d ,y 0d ,ψ] T , the error formula between the expected trajectory and the actual trajectory is:

[0030] e η (t) = η d (t)-η(t) (3);

[0031] When the error between the expected trajectory and the actual trajectory approaches zero, the feedback attitude control information can be obtained. The calculation formula is as follows:

[0032]

[0033] The posture control information that needs to be fed back is calculated by formulas (1)-(4), and the motion control module controls the servo motor to change the motion state of the robot according to the fed back posture control information.

[0034] Preferably, the sending of compressed and encoded temperature, turbidity, video signal, collision sonar, pressure, depth, and motion status data to the control center through the wireless communication module comprises the following steps:

[0035] Modulate the low-frequency digital signals of temperature, turbidity, video signals, impact sonar, pressure, depth, and motion status and then complete D / A conversion to obtain analog signals;

[0036] Perform frequency division processing on the analog signal and amplify the power of the frequency division signal;

[0037] The frequency-divided signal with amplified power is then sent to the control center.

[0038] Preferably, the video signal acquisition method is:

[0039] First, initialize the frame rate and resolution of the video acquisition sensor, configure the buffer, complete the establishment of the video acquisition sensor channel, and set the interface properties of the video acquisition sensor;

[0040] The ISP module is driven based on actual needs to process the image, and then the acquired image is sent to the VPSS module.

[0041] Preferably, compressing and encoding the collected data of temperature, turbidity, video signal, collision sonar, pressure, depth, and motion state according to the video data compression protocol comprises the following steps:

[0042] Configure the encoding format, bit rate and timestamp information;

[0043] Set H.264 encoding related parameters;

[0044] Get the encoded bitstream from the VPSS module;

[0045] After encoding is completed, the encoding channel will be destroyed.

[0046] The control system and method of the underwater monitoring robot for a ship provided by the present invention have the following advantages and beneficial effects:

[0047] The marine underwater monitoring robot of the present application can realize fixed depth control and posture control, and has relatively ideal motion control capability;

[0048] The camera can capture clear underwater images and feed the images back to the shore control center in real time;

[0049] The ship-borne underwater monitoring robot control system can operate accurately and stably and can work normally in shallow waters, which has an important impact on operations such as underwater monitoring in shallow waters. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a module diagram of a preferred embodiment of the control system of the marine underwater monitoring robot of the present application.

[0051] Figure 2 This is a video acquisition block diagram of a preferred embodiment of the control system of the marine underwater monitoring robot of the present application.

[0052] Figure 3 This is a schematic diagram of the servo motor control part in the motion control module of a preferred embodiment of the control system of the marine underwater monitoring robot of the present application.

[0053] Figure 4 This is the motion coordinate system of the underwater monitoring robot of the preferred embodiment of the control system of the ship underwater monitoring robot of the present application.

[0054] Figure 5 This is a yaw angle curve diagram of an underwater monitoring robot of a preferred embodiment of the control system of the ship's underwater monitoring robot of the present application.

[0055] Figure 6 This is a water depth control curve diagram of an underwater monitoring robot according to a preferred embodiment of the control system of an underwater monitoring robot for ships of the present application. DETAILED DESCRIPTION

[0056] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0057] It should be noted that when an element is considered to be "connected" to another element, it may be directly connected to the other element and integrated therewith, or there may be an intermediate element at the same time. The terms "mounted" and similar expressions used herein are for illustrative purposes only.

[0058] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0059] In one embodiment, Figure 1As shown, a control system of a marine underwater monitoring robot is provided, comprising the following steps: a main control module, wherein the main control module compresses and encodes the collected working environment data and motion posture data according to the video data compression protocol, and then sends the compressed and encoded working environment data and motion posture data to the control center through the wireless communication module, and the control center feeds back the posture control information to the main control module according to the demand, and the main control module controls the motion state of the robot through the motion control module after receiving the posture control information; an environmental information acquisition module, wherein the environmental information acquisition module is used to collect the video signal, turbidity and temperature of the working environment; a posture information acquisition module, wherein the posture information acquisition module is used to collect the collision sonar, pressure, depth and motion state information of the current robot; a wireless communication module, wherein the wireless communication module is used to send the collected working environment data and motion posture data to the control center after compression and encoding; and a motion control module, wherein the motion control module controls the robot to run according to the desired posture after receiving the posture control information fed back by the control center.

[0060] This application adopts the dual-core structure of STM32+DSP, cooperates with the power module, motor, wireless communication module, environmental information acquisition module and posture information acquisition module, and uses software technologies such as motion posture algorithm to make the performance of the underwater monitoring robot control system more stable.

[0061] In specific implementation, the main control module includes an STM32MP1 microprocessor and a TMS320C6472 microprocessor; the STM32MP1 microprocessor is used to drive the environmental information acquisition module and the posture information acquisition module; the TMS320C6472 microprocessor is used to compress and encode the collected environmental data operation and motion posture data according to the video data compression protocol, and receive the posture control information fed back by the control center.

[0062] During specific implementation, the environmental information acquisition module includes an LED lamp, a temperature sensor, a turbidity sensor and a video acquisition sensor.

[0063] The function of the environmental information acquisition module is to sense the working environment and obtain signals. Here we take the video signal as an example. The video signal is divided into two parts: acquisition and compression. The acquisition of video signals is achieved through Ethernet, HiSilicon Hi3516 chip, image sensor and other modules. The video acquisition block diagram is as follows Figure 2The operation process of this module is as follows: the HiSilicon Hi3516 processor collects image information and completes encoding, while the host computer at the control end implements the corresponding control function. The video acquisition input module collects the video signal, then transmits it to the VPSS video processing module and processes the image. Next, the VENC video encoding module completes the encoding, and finally uses the UDP target IP address and port to send it to the back-end control center.

[0064] In specific implementation, the posture information acquisition module includes a motion posture sensor, a depth sensor, a pressure sensor and a sonar sensor; the motion posture sensor adopts a nine-axis motion sensor with model MPU9250, and the nine-axis motion sensor includes a three-axis magnetometer, a three-axis gyroscope, a three-axis accelerometer and a DMP dynamic motion processor.

[0065] The attitude information acquisition module is the most important component in the underwater robot control system and is also the factor that determines the robot's control accuracy and performance. The magnetometer, gyroscope and accelerometer can obtain quaternions under the attitude fusion algorithm, and then convert them to Euler angles. The motion noise is eliminated through Kalman filtering. The motion control input data is Euler angles, which are then converted to output using the control algorithm, and finally the robot's attitude control function is realized.

[0066] In specific implementation, the motion control module includes a motion device and a control module. The motion control is achieved by a servo motor. The control method of the motion control module includes an open-loop control method and a closed-loop control method. The open-loop control method is used to control the movement of the robot, and the closed-loop control method is used to provide feedback on the movement posture of the robot.

[0067] The motion control module is implemented by using a servo motor, which is mainly composed of two parts: a motion device (thruster and steering gear) and a motion control module. Figure 3 The figure shows the schematic diagram of the servo motor control part in the motion control module. The control methods of underwater robot motion are divided into open-loop and closed-loop control methods. The open-loop control method mainly controls the robot motion, while the closed-loop control mainly provides feedback on the robot's motion posture and then controls its position. Through the motion control module, the robot can achieve six degrees of freedom (6-DOF) motion, including three translational degrees of freedom in the x, y, and z axes and three rotational degrees of freedom around the x, y, and z axes.

[0068] Of course, this application also includes a wireless communication module, which mainly includes a switch, an industrial computer, a recorder and a 4G router. The transceiver part of the control center set up on the shore is composed of a wireless communication transceiver, a 4G router module, an industrial computer, a switch, etc., while the underwater part is mainly based on a switch as the core transceiver device. Here we mainly introduce the acquisition of video signals. After the video signal is acquired, it is processed and compressed using a DSP digital signal processor, and then sent to the onshore control center with the help of the sending unit of the wireless communication module. The receiving unit of the onshore control center is mainly composed of an Internet of Things platform and a wireless communication module, and the data is transmitted in real time with the support of cellular mobile data.

[0069] This application also includes a power module, which is used to power the robot. Therefore, the stability of the power module has a decisive influence on the safe and stable operation of the system. The operating environment of this system is underwater, so the requirements for the power module are higher. The power module design needs to take into account the power supply requirements of all components in the system. The input voltage is processed by voltage stabilization and voltage reduction to safely power each component. The following table shows the core module power supply voltage value table.

[0070]

[0071] Based on the requirements of underwater monitoring robots in terms of power supply and robot power system, the power supply module finally selected a power supply with specifications of 3s~6s (12-24v), and designed the voltage stabilization circuit and power conversion circuit into the core control board. The system is powered by direct power supply mode, and the DC-DC conversion module is used to convert the power supply voltage to 3.3V or 5V to power other corresponding components.

[0072] The present application also provides a control method for a marine underwater monitoring robot, which comprises the following steps:

[0073] S100 uses the STM32MP1 microprocessor to drive the environmental information acquisition module and the attitude information acquisition module, turns on the LED light, and completes the data acquisition of temperature, turbidity, video signal, collision sonar, pressure, depth, and motion status;

[0074] S200, compressing and encoding the collected data of temperature, turbidity, video signal, collision sonar, pressure, depth, and motion status according to a video data compression protocol;

[0075] S300, sending compressed and encoded data of temperature, turbidity, video signal, collision sonar, pressure, depth, and motion status to the control center through the wireless communication module;

[0076] S400, the control center feeds back the posture control information to the main control module according to the demand, and the main control module controls the motion state of the robot through the motion control module after receiving the posture control information.

[0077] The motion characteristics of the ship underwater monitoring robot are analyzed by establishing a motion coordinate system. The coordinate system consists of the carrier coordinate system O-XYZ and the inertial coordinate system E-X0Y0Z0. The origin of the carrier coordinate system is the center of gravity O of the ship underwater monitoring robot, and the origin of the inertial coordinate system is the fixed point E in the water area, such as Figure 4 The motion coordinate system of the underwater robot is shown.

[0078] In order to achieve more efficient and convenient calculations, this application selects the carrier coordinate system and uses the underwater monitoring robot rigid body as the reference to complete the establishment of the coordinate system. Because the moment of inertia and product of inertia are related to the robot's mass, density, and shape, the moment of inertia and product of inertia of the underwater monitoring robot can be regarded as constants, and the direction and thrust of the robot will change during movement.

[0079] In specific implementation, the control center feeds back the posture control information to the main control module according to the demand, and after receiving the posture control information, the main control module controls the motion state of the robot through the motion control module, including:

[0080] In the inertial coordinate system, the robot's position is represented by coordinates (x0, y0, z0), and the robot's attitude angle is represented by (φ, θ, ψ). θ, ψ represent the roll angle, pitch angle, and heading angle, respectively. In the carrier coordinate system, (p, q, r) and (u, v, w) are used to represent the angular velocity and linear velocity of the robot. The following formula is the robot kinematic transformation equation:

[0081]

[0082] In formula (1), the robot position and angle in the inertial coordinate system are The linear velocity and angular velocity of the robot in the carrier coordinate system are V = [u0, v0, w0, p, q, r] T , the pose conversion matrix between the carrier coordinate system and the inertial coordinate system is represented by J(η);

[0083] The position and angle variables in the inertial coordinate system and the angular velocity and linear velocity variables in the carrier coordinate system have the following relationship:

[0084]

[0085] Assume that the expected trajectory given in advance is η d =[x 0d ,y 0d ,ψ] T, the error formula between the expected trajectory and the actual trajectory is:

[0086] e η (t) = η d (t)-η(t) (3);

[0087] When the error between the expected trajectory and the actual trajectory approaches zero, the feedback attitude control information can be obtained. The calculation formula is as follows:

[0088]

[0089] The posture control information that needs to be fed back is calculated by formulas (1)-(4), and the motion control module controls the servo motor to change the motion state of the robot according to the fed back posture control information.

[0090] Of course, the wireless communication module also includes a receiving subprogram unit, and its receiving principle is: first, the array receives the signal, filters out the low noise therein, then performs A / D conversion, demodulates the signal and then receives it.

[0091] In specific implementation, the sending of compressed and encoded temperature, turbidity, video signal, collision sonar, pressure, depth, and motion status data to the control center through the wireless communication module includes the following steps:

[0092] Modulate the low-frequency digital signals of temperature, turbidity, video signals, impact sonar, pressure, depth, and motion status and then complete D / A conversion to obtain analog signals;

[0093] Perform frequency division processing on the analog signal and amplify the power of the frequency division signal;

[0094] The frequency-divided signal with amplified power is then sent to the control center.

[0095] In specific implementation, the method of collecting the video signal is:

[0096] First, initialize the frame rate and resolution of the video acquisition sensor, configure the buffer, complete the establishment of the video acquisition sensor channel, and set the interface properties of the video acquisition sensor;

[0097] The ISP module is driven based on actual needs to process the image, and then the acquired image is sent to the VPSS module.

[0098] In specific implementation, compressing and encoding the collected data of temperature, turbidity, video signal, collision sonar, pressure, depth, and motion state according to the video data compression protocol includes the following steps:

[0099] Configure the encoding format, bit rate and timestamp information;

[0100] Set H.264 encoding related parameters;

[0101] Get the encoded bitstream from the VPSS module;

[0102] After encoding is completed, the encoding channel will be destroyed.

[0103] The control method of the marine underwater monitoring robot of the present application first obtains the system's operating environment information and motion posture data, and transmits them to the background control center, which determines the system operation mode and then completes the initialization operation of the operation mode. If it is an automatic mode, the motor, motion posture and device position are controlled. If it is a manual mode, the remote control command is received, and the mechanical arm and propeller motor are controlled, so that the marine underwater monitoring robot can operate normally.

[0104] The H.264 compression coding standard has the advantages of high adaptability and good compression rate. It is the most widely used in video communications and has more advantages than other standards.

[0105] The size of the robot in this application is preferably 500mm×400mm×300mm. In order to test the control system's control effect on the robot's motion and posture, the test was conducted in a reservoir. The test environment of the reservoir is a 3m×2m×2m reservoir with a water depth of 1.6m. The robot motion experiment is mainly carried out to perform linear motion, rotational motion and fixed-depth motion underwater to observe the motion state of the dredging inspection robot.

[0106] like Figure 5 As shown in the figure, the yaw angle curve of the robot in the pool moves in the order of linear motion, turning motion, turning motion and linear motion. It can be seen from the figure that the robot's initial heading angle is 120° between 1s and 51s, and it turns from 0° to 360° between 51s and 101s, and increases from 0° to 360° between 151s and 201s, and finally stabilizes at about 120° after 201 seconds. During the entire process of the robot moving under the pool, the instructions issued by the background control center can be accurately and stably executed.

[0107] The underwater monitoring robot also needs to complete the depth control test, which can be achieved through the depth step response experiment. When the robot just approaches the water surface, the host computer depth is set to 85 cm. Then the robot sensor information will be recorded by the host computer. After testing, the following is obtained: Figure 6The depth control curve is shown in the figure. According to the curve, it can be found that the robot's depth value is very close to 0 at the beginning, and the fluctuation range is relatively small. This is because the upper part of the robot is about to be submerged by the water surface. The flow of water will interfere with the measured water pressure value to a certain extent, so the fluctuation is understandable; when the upper computer sends the set depth data, the depth value increases in a short time, and the robot will quickly dive underwater. When the robot is about to dive to a depth of 85CM, it will continue to slow down. After reaching a depth of 85cm, there will be an overshoot, but the overshoot will not be large, and it will finally stabilize at this depth. During the entire process of the underwater monitoring robot diving underwater, the water body nearby will fluctuate, so there will be a certain error in the water pressure measurement result, which will of course interfere with the depth control to a certain extent.

[0108] This application provides a control system for a ship underwater monitoring robot, and tests it in a rectangular pool. After actual testing, it can be seen that the ship underwater monitoring robot can achieve fixed depth control and posture control in the pool, and the motion control ability is also relatively ideal, which meets the design requirements; the camera can take clear pictures of the underwater scene and feed back the image to the shore control center in real time. Finally, after experiments, the ship underwater monitoring robot control system can operate accurately and stably, and can work normally in shallow waters, which has an important impact on shallow water underwater monitoring and other operational fields.

[0109] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0110] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A control system for a marine underwater monitoring robot, characterized in that: include: A main control module, which compresses and encodes the collected working environment data and motion posture data according to the video data compression protocol, and then sends the compressed and encoded working environment data and motion posture data to the control center through the wireless communication module. The control center feeds back the posture control information to the main control module according to the demand. After receiving the posture control information, the main control module controls the motion state of the robot through the motion control module; An environmental information acquisition module, which is used to collect video signals, turbidity and temperature of the working environment; A posture information collection module, which is used to collect collision sonar, pressure, depth and motion state information of the current robot; A wireless communication module, which is used to compress and encode the collected working environment data and motion posture data and send them to the control center; The motion control module controls the robot to run in a desired posture after receiving the posture control information fed back by the control center.

2. The control system of the underwater monitoring robot for ships according to claim 1, characterized in that: The main control module includes an STM32MP 1 microprocessor and a TMS320C6472 microprocessor; The STM32MP1 microprocessor is used to drive the environment information acquisition module and the posture information acquisition module; The TMS320C6472 microprocessor is used to compress and encode the collected working environment data and motion posture data according to the video data compression protocol, and receive the posture control information fed back by the control center.

3. The control system of the underwater monitoring robot for ships according to claim 1, characterized in that: The environmental information acquisition module includes an LED lamp, a temperature sensor, a turbidity sensor and a video acquisition sensor.

4. The control system of the underwater monitoring robot for ships according to claim 3, characterized in that: The posture information acquisition module includes a motion posture sensor, a depth sensor, a pressure sensor and a sonar sensor; The motion posture sensor adopts a nine-axis motion sensor of model MPU9250, and the nine-axis motion sensor includes a three-axis magnetometer, a three-axis gyroscope, a three-axis accelerometer and a DMP dynamic motion processor.

5. The control system of the underwater monitoring robot for ships according to claim 4, characterized in that: The motion control module includes a motion device and a control module. The motion control is achieved by a servo motor. The control method of the motion control module includes an open-loop control method and a closed-loop control method. The open-loop control method is used to control the motion of the robot, and the closed-loop control method is used to provide feedback on the motion posture of the robot.

6. A control method for a marine underwater monitoring robot, characterized in that: The steps include: The STM32MP1 microprocessor is used to drive the environmental information acquisition module and the attitude information acquisition module, turn on the LED light, and complete the data acquisition of temperature, turbidity, video signal, collision sonar, pressure, depth, and motion status; The collected data of temperature, turbidity, video signal, collision sonar, pressure, depth, and motion status are compressed and encoded according to the video data compression protocol; Send compressed and encoded data of temperature, turbidity, video signal, collision sonar, pressure, depth, and motion status to the control center through the wireless communication module; The control center feeds back the posture control information to the main control module according to the demand. After receiving the posture control information, the main control module controls the motion state of the robot through the motion control module.

7. The control method of the underwater monitoring robot for ships according to claim 6, characterized in that: The control center feeds back the posture control information to the main control module according to the demand. After receiving the posture control information, the main control module controls the motion state of the robot through the motion control module, including: In the inertial coordinate system, the robot's position is represented by coordinates (x0, y0, z0), and the robot's attitude angle is represented by (φ, θ, ψ). θ, ψ represent the roll angle, pitch angle, and heading angle, respectively. In the carrier coordinate system, (p, q, r) and (u, v, w) are used to represent the angular velocity and linear velocity of the robot. The following formula is the robot kinematic transformation equation: In formula (1), the robot position and angle in the inertial coordinate system are The linear velocity and angular velocity of the robot in the carrier coordinate system are V = [u0, v0, w0, p, q, r] T , the pose conversion matrix between the carrier coordinate system and the inertial coordinate system is represented by J(η); The position and angle variables in the inertial coordinate system and the angular velocity and linear velocity variables in the carrier coordinate system have the following relationship: Assume that the expected trajectory given in advance is η d =[x 0d ,y 0d ,ψ] T , the error formula between the expected trajectory and the actual trajectory is: e η (t)=η d (t)-η(t) (3); When the error between the expected trajectory and the actual trajectory approaches zero, the feedback attitude control information can be obtained. The calculation formula is as follows: The posture control information that needs to be fed back is calculated by formulas (1)-(4), and the motion control module controls the servo motor to change the motion state of the robot according to the fed back posture control information.

8. The control method of the underwater monitoring robot for ships according to claim 6, characterized in that: The method of sending compressed and encoded temperature, turbidity, video signal, impact sonar, pressure, depth, and motion status data to the control center through the wireless communication module includes the following steps: Modulate the low-frequency digital signals of temperature, turbidity, video signals, impact sonar, pressure, depth, and motion status and then complete D / A conversion to obtain analog signals; Perform frequency division processing on the analog signal and amplify the power of the frequency division signal; The frequency-divided signal with amplified power is then sent to the control center.

9. The control method of the underwater monitoring robot for ships according to claim 6, characterized in that: The method of video signal acquisition is: First, initialize the frame rate and resolution of the video acquisition sensor, configure the buffer, complete the establishment of the video acquisition sensor channel, and set the interface properties of the video acquisition sensor; The ISP module is driven based on actual needs to process the image, and then the acquired image is sent to the VPSS module.

10. The control method of the underwater monitoring robot for ships according to claim 6, characterized in that: The method of compressing and encoding the collected data of temperature, turbidity, video signal, collision sonar, pressure, depth, and motion state according to the video data compression protocol comprises the following steps: Configure the encoding format, bit rate and timestamp information; Set H.264 encoding related parameters; Get the encoded bitstream from the VPSS module; After encoding is completed, the encoding channel will be destroyed.

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