阅读说明：本技术 一种基于rs485总线的八推进器水下机器人控制系统 (Eight-propeller underwater robot control system based on RS485 bus ) 是由 董旭 王飞旋 罗东明 李一顺 胡若愚 张文玉 白香雪 杨松柏 解毅 于 2020-09-30 设计创作，主要内容包括：本发明提出一种8个推进器水下机器人控制系统,所述的水下机器人有4个顶部推进器和4个矢量推进器,8个推进器共同或者部分工作,完成智能机器人平台的6自由度运动。保证其姿态稳定,能够定向、定深、定速航行。控制系统的综合控制计算机通过RS485总线连接多个传感器单元,用于水下机器人的深度温度测量,姿态测量,速度测量和漏水监测,还具备照明和图像传输模块,以获得水下目标的实时视频信息,辅助照明光源的亮度控制使用RS485总线进行控制,使操作人员更加方便对水下机器人进行作业控制。(The invention provides an underwater robot control system with 8 propellers, wherein the underwater robot is provided with 4 top propellers and 4 vector propellers, and the 8 propellers work together or partially to complete 6-degree-of-freedom movement of an intelligent robot platform. Ensures the stable posture and can navigate directionally, at a fixed depth and at a fixed speed. The comprehensive control computer of the control system is connected with the plurality of sensor units through the RS485 bus and is used for depth temperature measurement, attitude measurement, speed measurement and water leakage monitoring of the underwater robot, the comprehensive control computer further comprises an illumination and image transmission module so as to obtain real-time video information of an underwater target, the brightness control of the auxiliary illumination light source is controlled by the RS485 bus, and therefore an operator can more conveniently control the operation of the underwater robot.)

1. An eight-propeller underwater robot control system based on an RS485 bus is characterized in that the control system consists of an RS485 control bus, a comprehensive control computer, an underwater propeller, a sensor unit, a power supply unit and an illumination and image acquisition unit; the comprehensive control computer can output 8 paths of PWM signals, control the rotating direction and the rotating speed of 8 propellers of the underwater robot and finish 6-degree-of-freedom motion, depth navigation and constant-speed navigation of the underwater robot platform; the other unit devices are controlled by an RS485 communication bus of the comprehensive control computer; the underwater propeller comprises 4 top propellers arranged at the top of the underwater robot and embedded in the middle of the floating body material, and 4 vector propellers arranged at the bottom of the robot; the 4 top thrusters are embedded in the middle of the floating body material and are symmetrically arranged, the installation direction of the top thrusters is vertical to the horizontal direction of the underwater robot, and the top thrusters can synchronously or asynchronously rotate in a differential manner, can rotate forwards or reversely, and are used for pushing the underwater robot to complete the functions of ascending, descending, pitching and rolling; the included angles of two symmetrical vector thrusters in the vector thrusters and the underwater robot in the horizontal direction are the same, the included angle of the vector thrusters and the course of the underwater robot is 60 degrees, the included angle with the lateral direction is 30 degrees, the rotating speed can synchronously or asynchronously rotate in a differential mode, the underwater robot can rotate forwards or reversely, and the vector thrusters are used for pushing the underwater robot to move left and right, move in the 45-degree oblique direction and rotate in place; the sensor unit includes: the system comprises a depth temperature measuring unit, an attitude measuring unit, a speed measuring unit, an electric energy monitoring unit and a water leakage monitoring unit; the depth temperature measuring unit comprises waterproof glue and a antimagnetic stainless steel ring, outputs 24-bit pressure and temperature digital signals, and outputs high-resolution temperature digital signals to indicate actual temperature; the attitude measurement unit comprises an attitude measurement module, and the attitude measurement unit receives GPS signal data to form a GPS-IMU integrated navigation unit; the comprehensive control computer reads the attitude angle information of the attitude sensor through an RS485 bus; the speed measuring unit comprises a pulse signal counting sensor used for collecting electrically-regulated pulse signal counting feedback, the actual rotating speed of each propeller is converted according to the pulse number collected by the pulse signal counting sensor according to a specified proportion, and the comprehensive control computer reads the actual rotating speed of each propeller through an RS485 bus to obtain the moving speed of the underwater robot; the water leakage monitoring unit is used for monitoring whether the electronic sealed cabin leaks water or not, giving a water leakage monitoring signal, receiving the water leakage signal of the electronic sealed cabin by the comprehensive control computer and sending an instruction to control the underwater robot to stop working when power is off; the power supply unit is provided with a soft start module, has input protection and output protection, and can be monitored in real time by the comprehensive control computer and adjust output voltage through a background; the illumination image acquisition combination unit is used for acquiring real-time video information of an underwater target, the video information is subjected to data transmission through the Ethernet, and the illumination unit provides an auxiliary light source for the image acquisition module for illumination and is used for improving the shooting effect; the brightness control of the lighting unit is controlled by using an RS485 bus, and different brightness of the lighting lamp is set by the comprehensive control computer; all sensor output signals comprise converters, the sensing signals are converted into signals conforming to the RS485 communication protocol, and the signals are transmitted to the comprehensive control computer through the bus.

2. The underwater robot control system of claim 1, wherein: the propeller rotating shaft of the top propeller is vertical to the horizontal section of the underwater robot; the propeller rotating shaft of the vector thruster is parallel to the horizontal section of the underwater robot, and the course included angles of the two groups of vector thrusters which are arranged diagonally in front and back are respectively 60 degrees according to a clockwise included angle and 60 degrees according to a counterclockwise included angle.

3. The underwater robot control system of claim 1, wherein: the attitude measurement unit comprises an attitude measurement module, and the attitude measurement module consists of a high-precision gyroscope, an accelerometer and a geomagnetic field sensor; and the comprehensive control computer automatically controls the top propeller to modify the rotating speed according to the read attitude angle change of the attitude sensor, so that the moving attitude of the underwater robot is kept stable.

4. The underwater robot control system of claim 1, wherein: the speed measuring unit comprises a signal isolation module, a pulse signal capture module, a signal conversion module and an RS485 serial communication module; the speed measuring unit collects electrically-adjusted pulse signal counts and feeds back the electrically-adjusted pulse signal counts to the comprehensive control computer, the pulse return signals are in direct proportion to the actual rotating speed of the propellers, the ratio is 1:7, the comprehensive control computer obtains the actual rotating speed of each propeller through the pulse signal counts read by the RS485 bus, and then the moving speed of the underwater robot is calculated.

5. The underwater robot control system of claim 1, wherein: the depth temperature measuring unit adopts an MS5837-30BA sensor.

6. The underwater robot control system of claim 1, wherein: the attitude measurement unit comprises an attitude measurement module, the attitude measurement module integrates a high-precision gyroscope, an accelerometer, a geomagnetic field sensor and a high-performance microprocessor, an attitude resolver is integrated in the attitude measurement module, and the attitude measurement precision is static at 0.05 degree and dynamic at 0.1 degree by using a dynamic Kalman filtering algorithm; the attitude measurement module supports an RS485 communication interface.

7. The underwater robot control system of claim 1, wherein: the electric energy monitoring unit adopts an optical fiber sensor and comprises an optical fiber current sensor, a transmitting and receiving optical fiber and an electronic loop.

8. The underwater robot control system of claim 1, wherein: the water leakage detection unit adopts a BlueROV suite, converts GPIO signals into an RS485 communication protocol through the digital signal conversion unit, and the comprehensive control computer reads the water leakage detection sensor data through an RS485 bus.

9. The underwater robot control system of claim 1, wherein: the power supply unit is a R4850G6 direct current power supply module.

10. The underwater robot control system of claim 1, wherein: the integrated control computer adopts STM32F407 of an ideological semiconductor.

Technical Field

The invention relates to the field of underwater robot control, in particular to an underwater robot control system taking an RS485 bus as a data transmission mode.

Background

The underwater robot control system is used for finishing the accurate control of the underwater robot in water, and comprises depth navigation, constant-speed navigation, directional navigation, positioning hovering and the like under the interference of complex ocean currents, so that the problems of accurate control, signal acquisition and the like of multiple propellers and multiple sensors are involved.

A typical application is a patent with application number CN201810345904.6, which discloses a bimodal six-degree-of-freedom underwater robot, comprising a power system, an acquisition system and a control system. The power system and the acquisition system are both arranged on an underwater robot body, and the underwater robot body comprises a sealed cabin; the power system comprises a Z-direction propelling mechanism, an X-direction propelling mechanism and a Y-direction propelling mechanism, wherein the Z-direction propelling mechanism, the X-direction propelling mechanism and the Y-direction propelling mechanism are all installed on the underwater robot body.

How to coordinate the relation between walking and attaching of the underwater robot is a key problem of the current underwater robot technology. The underwater environment is extremely complex, the water pressure is increased along with the increase of the submergence depth of the robot, and the existing underwater wheel type wall-climbing robot mostly adopts driving wheels, namely the wheels are driven by a motor, so that the wheels obtain the friction force which is the same with the movement direction on a contact surface to realize the movement of the robot. However, in practical engineering, the underwater wall surface is often covered by algae, moss or the like or is attached with silt and the like, so that the robot slips and is difficult to keep moving normally. In addition, the existing underwater robot has complex mode conversion, particularly when the navigation is converted into the movement by the wall, the posture of the robot needs to be continuously adjusted, and the operation process is complex.

Disclosure of Invention

In order to solve the technical problem, the invention provides an underwater robot control system based on an RS485 bus, wherein the RS485 bus adopts a communication mode that one master has multiple slaves, and can be connected with 255 RS485 interface devices at most for control and communication. In the underwater robot control system, the integrated control computer is a master device, and all sensors are slave devices.

The invention provides an eight-propeller underwater robot control system based on an RS485 bus, which is characterized in that the control system consists of the RS485 control bus, a comprehensive control computer, an underwater propeller, a sensor unit, a power supply unit and an illumination and image acquisition unit; the comprehensive control computer can output 8 paths of PWM signals, control the rotating direction and the rotating speed of 8 propellers of the underwater robot and finish 6-degree-of-freedom motion, depth navigation and constant-speed navigation of the underwater robot platform; the other unit devices are controlled by an RS485 communication bus of the comprehensive control computer; the underwater propeller comprises 4 top propellers arranged at the top of the underwater robot and embedded in the middle of the floating body material, and 4 vector propellers arranged at the bottom of the robot; the 4 top thrusters are embedded in the middle of the floating body material and are symmetrically arranged, the installation direction of the top thrusters is vertical to the horizontal direction of the underwater robot, and the top thrusters can synchronously or asynchronously rotate in a differential manner, can rotate forwards or reversely, and are used for pushing the underwater robot to complete the functions of ascending, descending, pitching and rolling; the included angles of two symmetrical vector thrusters in the vector thrusters and the underwater robot in the horizontal direction are the same, the included angle of the vector thrusters and the course of the underwater robot is 60 degrees, the included angle with the lateral direction is 30 degrees, the rotating speed can synchronously or asynchronously rotate in a differential mode, the underwater robot can rotate forwards or reversely, and the vector thrusters are used for pushing the underwater robot to move left and right, move in the 45-degree oblique direction and rotate in place; the sensor unit includes: the system comprises a depth temperature measuring unit, an attitude measuring unit, a speed measuring unit, an electric energy monitoring unit and a water leakage monitoring unit; the depth temperature measuring unit comprises waterproof glue and a antimagnetic stainless steel ring, outputs 24-bit pressure and temperature digital signals, and outputs high-resolution temperature digital signals to indicate actual temperature; the attitude measurement unit comprises an attitude measurement module, and the attitude measurement unit receives GPS signal data to form a GPS-IMU integrated navigation unit; the comprehensive control computer reads the attitude angle information of the attitude sensor through an RS485 bus; the speed measuring unit comprises a pulse signal counting sensor used for collecting electrically-regulated pulse signal counting feedback, the actual rotating speed of each propeller is converted according to the pulse number collected by the pulse signal counting sensor according to a specified proportion, and the comprehensive control computer reads the actual rotating speed of each propeller through an RS485 bus to obtain the moving speed of the underwater robot; the water leakage monitoring unit is used for monitoring whether the electronic sealed cabin leaks water or not, giving a water leakage monitoring signal, receiving the water leakage signal of the electronic sealed cabin by the comprehensive control computer and sending an instruction to control the underwater robot to stop working when power is off; the power supply unit is provided with a soft start module, has input protection and output protection, and can be monitored in real time by the comprehensive control computer and adjust output voltage through a background; the illumination image acquisition combination unit is used for acquiring real-time video information of an underwater target, the video information is subjected to data transmission through the Ethernet, and the illumination unit provides an auxiliary light source for the image acquisition module for illumination and is used for improving the shooting effect; the brightness control of the lighting unit is controlled by using an RS485 bus, and different brightness of the lighting lamp is set by the comprehensive control computer; all sensor output signals comprise converters, the sensing signals are converted into signals conforming to the RS485 communication protocol, and the signals are transmitted to the comprehensive control computer through the bus.

Further, a propeller rotating shaft of the top propeller is vertical to the horizontal section of the underwater robot; the propeller rotating shaft of the vector thruster is parallel to the horizontal section of the underwater robot, and the course included angles of the two groups of vector thrusters which are arranged diagonally in front and back are respectively 60 degrees according to a clockwise included angle and 60 degrees according to a counterclockwise included angle.

Furthermore, the attitude measurement unit comprises an attitude measurement module, and the attitude measurement module consists of a high-precision gyroscope, an accelerometer and a geomagnetic field sensor; and the comprehensive control computer automatically controls the top propeller to modify the rotating speed according to the read attitude angle change of the attitude sensor, so that the moving attitude of the underwater robot is kept stable.

Furthermore, the speed measuring unit comprises a signal isolation module, a pulse signal capture module, a signal conversion module and an RS485 serial communication module; the speed measuring unit collects electrically-adjusted pulse signal counts and feeds back the electrically-adjusted pulse signal counts to the comprehensive control computer, the pulse return signals are in direct proportion to the actual rotating speed of the propellers, the ratio is 1:7, the comprehensive control computer obtains the actual rotating speed of each propeller through the pulse signal counts read by the RS485 bus, and then the moving speed of the underwater robot is calculated.

Further, the depth temperature measuring unit adopts an MS5837-30BA sensor.

Further, the attitude measurement unit comprises an attitude measurement module, the attitude measurement module integrates a high-precision gyroscope, an accelerometer and a geomagnetic field sensor and contains a high-performance microprocessor, an attitude resolver is integrated in the attitude measurement module, and the attitude measurement precision is static at 0.05 degree and dynamic at 0.1 degree by using a dynamic Kalman filtering algorithm; the attitude measurement module supports an RS485 communication interface.

Furthermore, the electric energy monitoring unit adopts an optical fiber sensor, and comprises an optical fiber current sensor, a transmitting and receiving optical fiber and an electronic loop.

Furthermore, the water leakage detection unit adopts a BlueROV suite, converts the GPIO signals into an RS485 communication protocol through the digital signal conversion unit, and the comprehensive control computer reads the water leakage detection sensor data through an RS485 bus.

Further, the power supply unit is a dc power supply module, which is R4850G 6. The integrated control computer adopts STM32F407 of an ideological semiconductor.

The invention adopts a communication mode of one master with multiple slaves based on an RS485 bus, and can be connected with 255 RS485 interface devices at most for control and communication. In the underwater robot control system, the integrated control computer is a master device, and all sensors are used as slave devices.

The underwater robot control system of the invention sends PWM signals through a comprehensive control computer to control the rotating directions and rotating speeds of 8 propellers. External information is sensed through the sensor unit and packaged into an RS485 bus communication format to form a controlled feedback signal. The comprehensive control computer analyzes, judges and processes the feedback signals of all paths through the RS485 bus, modifies the control law, enables the whole underwater robot to move according to the expected direction and speed, and displays the working state of each unit in the working process of the whole control system for monitoring.

Drawings

FIG. 1; the control system is formed into a diagram.

FIG. 2; and installing a position diagram of the propeller in the underwater robot.

FIG. 3: the mounting position of the top thruster.

FIG. 4: the installation position of the vector thruster.

FIG. 5: MS5837-30BA depth temperature sensor.

FIG. 6: speed measurement unit circuit diagram.

FIG. 7: and (4) a system block diagram of the electric energy monitoring unit.

FIG. 8: and (4) a water leakage detection schematic diagram.

FIG. 9: a water leakage detection mainboard circuit diagram.

Detailed Description

The following detailed description of the invention refers to the accompanying drawings of which figures 1-9 illustrate specific embodiments.

The invention provides an eight-propeller underwater robot control system based on an RS485 bus.

The first embodiment.

The invention provides an overall technical scheme of an eight-propeller underwater robot control system based on an RS485 bus

4.1 control System composition of Underwater robot

The control system consists of an RS485 control bus, a comprehensive control computer, an underwater propeller, a sensor unit, a power supply unit and an illumination and image acquisition unit. The underwater propeller is controlled by a PWM signal sent by a comprehensive control computer, and other unit equipment is controlled by an RS485 communication bus. The comprehensive control computer is the core of the whole control system, adopts an ARM embedded system and is responsible for outputting a propeller PWM signal, sending out an RS485 bus control instruction, receiving state data of a sensor unit, outputting a relay signal, transmitting image data and the like. The underwater robot control system is shown in the attached figure 1.

4.2 control System principle of Underwater robot

The underwater robot control system has the function of controlling the rotating directions and the rotating speeds of the 8 propellers by sending PWM signals through the comprehensive control computer. Meanwhile, the sensor unit senses various external information, and the sensing information is packaged into an RS485 bus communication format to form a control feedback signal. The comprehensive control computer receives various control feedback signals from the RS485 bus, analyzes, judges and processes the signals, corrects the control rule, enables the whole underwater robot to move according to the expected direction and speed, and displays the working state of each unit in the working process of the whole control system for monitoring.

The motion of underwater robot is realized through the propeller, and underwater robot total 8 propellers, 4 top propellers and 4 vector thrusters, 8 propellers are common or partial work, accomplish intelligent robot platform's 6 degrees of freedom motions. The mounting position of the thruster in the robot is shown in fig. 2.

4.2.1 attitude stabilization of an Underwater robot

4 top thrusters are arranged at the top of the robot, embedded in the middle of the floating body material and symmetrically distributed. The functions of ascending, descending, pitching and rolling are completed, and the mounting position of the top propeller is shown in figure 3.

The operation of vector propeller can form reaction moment to underwater robot, can arouse often that the robot beats and changes or rolls, and underwater intelligent robot is very high to positioning accuracy requirement, in order to avoid appearing the robot and roll, often takes a plurality of propellers symmetrical arrangement mode. When the symmetrically arranged propellers work, all thrust forces should be converged at one point, and the point can be close to the horizontal center of gravity of the underwater robot, so that the efficiency of the propellers can be improved, and the phenomenon of instability in motion is avoided.

In the process of ascending, descending or hovering of the underwater robot, the attitude measurement unit can measure the attitude azimuth angle of the current robot in real time through the sensor, and the comprehensive control computer reads the attitude angle information of the attitude sensor through the RS485 bus. Under the condition of complex ocean current, if the attitude angle changes when the vehicle hovers over, the comprehensive control computer can automatically control the top propeller to modify the rotating speed, and the motion attitude of the underwater robot is kept stable.

4.2.2 Directional navigation of Underwater robot

In order to enable the underwater robot to easily move in four directions, namely front, back, left and right directions in the moving process, 4 horizontal propellers are symmetrically arranged in a vector mode and are also called as vector propellers. The mounting position of the vector thruster is shown in fig. 4.

During underwater movement of the underwater robot, the forward movement and the backward movement are far higher than the left movement and the right movement, so that a thruster is required to provide larger thrust in the forward direction and the lateral direction. Therefore, the angle of the vector thruster is 60 degrees relative to the heading and 30 degrees relative to the lateral direction, so as to achieve the best thrust efficiency.

The motion mode of the underwater robot is analyzed from the vector propeller installation position diagram, and the underwater robot can move forwards or backwards when the propellers 1,2,3 and 4 rotate forwards or backwards at a certain speed; when the four propellers have the same rotating speed and the rotating directions of the propellers 1 and 3 are opposite to the rotating directions of the propellers 2 and 4, the underwater robot chassis can move left and right.

When the speeds and the directions of the propellers 1 and 3 are the same and the propellers 2 and 4 are not moved or the speeds and the directions of the propellers 2 and 4 are the same and the propellers 1 and 3 are not moved, the underwater robot can move in the direction inclined by 45 degrees; when the speeds of the 4 propellers are the same, and the directions of the propellers 1 and 4 are opposite to the directions of the propellers 2 and 3, the underwater robot can do in-situ rotation movement.

4.2.3 constant speed navigation

The comprehensive control computer controls the rotation of the propeller by sending the PWM wave to the electric regulator, and a pulse return signal is arranged in the electric regulator, wherein the pulse return signal is in direct proportion to the actual rotating speed of the propeller, and the ratio is 1: 7. In the process that the robot moves towards a specific direction at a certain speed, the speed measuring unit can monitor the pulse feedback signal of the propeller all the time, and under the condition of complex ocean currents, if the pulse feedback signal fluctuates in the navigation process to indicate that the speed at the current moment changes, the comprehensive control computer can automatically control the vector propeller to modify the rotating speed, so that the navigation speed of the underwater robot is kept stable.

4.2.4 navigation at fixed depth

The underwater robot control system comprises a depth pressure sensor, the integrated control computer collects the depth information of the depth pressure sensor through a 485 bus in the process of setting the depth-fixing navigation of the underwater robot, and under the condition of complex ocean current, if the depth changes in the navigation process, the integrated control computer can automatically control a top propeller to modify the rotating speed, so that the underwater robot can be kept in a stable navigation depth.

4.3 Integrated control computer

The integrated control computer adopts STM32F4 series of ideographic semiconductor, and STM32F407 series is oriented to medical, industrial and consumer applications requiring high integration, high performance, embedded memory and peripherals in a package as small as 10 x 10 mm. STM32F407 provides the performance of Cortex-M4 kernel with 168MHz working frequency, STM32F407 has the following abundant interfaces, the control of the underwater robot can be conveniently completed through the interfaces, and processor interfaces occupied in the control system are shown in Table 1.

TABLE 1 STM32F407 interface usage description

4.4 sensor Unit of an Underwater robot

4.4.1 depth temperature measurement Unit

The depth temperature measuring unit adopts an MS5837-30BA sensor, the shape structure of which is shown in figure 5, and the depth temperature measuring unit comprises waterproof glue and a antimagnetic stainless steel ring so that the sensor can be waterproof. MS5837-30BA is a new generation of high resolution I²C interface pressure sensor, sensor module are based on advanced MEMS technique, and the depth of water measurement resolution ratio reaches 2 mm. The sensor module comprises a high-linearity pressure sensing element and an ultra-low power consumption 24-bit AD acquisition functional module. The MS5803-30BA provides high precision 24 bit pressure and temperature digital output, and the high resolution temperature output can simultaneously realize the function of a thermometer. Standard MS5837-30BA sensor use I²C interface, converting I into digital signal in depth temperature measuring unit²And the communication protocol C is converted into an RS485 communication protocol, so that the data of the sensor can be conveniently read by the bus.

4.4.2 attitude measurement Unit

The attitude measurement module integrates a high-precision gyroscope, an accelerometer and a geomagnetic field sensor, and can quickly solve the current real-time motion attitude of the module by adopting a high-performance microprocessor and an advanced dynamic solution and Kalman dynamic filtering algorithm.

By adopting an advanced digital filtering technology, the measurement noise can be effectively reduced, and the measurement precision is improved. An attitude resolver is integrated in the module, and the current attitude of the module can be accurately output under a dynamic environment by matching with a dynamic Kalman filtering algorithm, wherein the attitude measurement precision is static 0.05 degree, the attitude measurement precision is dynamic 0.1 degree, and the stability is extremely high. The attitude measurement unit has GPS connection capability. And receiving serial port GPS data meeting the NMEA-0183 standard to form a GPS-IMU combined navigation unit. The attitude measurement module supports an RS485 communication interface, and the comprehensive control computer on the RS485 bus can conveniently read the data of the attitude sensor and control the robot.

4.4.3 speed measurement Unit

The comprehensive control computer controls the rotation of the propeller by sending the PWM wave to the electric regulator, and a pulse return signal is arranged in the electric regulator, wherein the pulse return signal is in direct proportion to the actual rotating speed of the propeller, and the ratio is 1: 7. The control system of the underwater robot comprises a pulse signal counting sensor which is used for collecting electrically-regulated pulse signal counting feedback, and the pulse number collected by the pulse signal sensor is converted into the actual rotating speed of a propeller according to the proportion, so that a speed measuring unit of the underwater robot control system is formed. A diagram of the speed measuring unit is shown in fig. 6.

The speed measuring unit comprises signal isolation, pulse signal capture, signal conversion and RS485 serial communication. The speed measuring unit is an intelligent acquisition system based on a single chip microcomputer, state information is stored in an EEPROM (electrically erasable programmable read-only memory), signal output/output is isolated, and 8 paths of pulse counting signals can be acquired simultaneously.

4.4.4 electric energy monitoring Unit

The electric energy monitoring of the whole control system adopts an optical fiber sensor, and the system block diagram of the electric energy monitoring unit is shown in the attached figure 7. Compared with magnetoelectric current detection, the optical fiber current sensor has the advantages of good insulating property, high measurement accuracy, strong anti-interference capability, high safety, small volume and the like. The electric energy monitoring unit mainly comprises three parts, namely an optical fiber current sensor, a transmitting and receiving optical fiber, an electronic loop and the like, wherein the sensing head comprises a current-carrying conductor, a sensing optical fiber wound on the current-carrying conductor, and optical components such as a polarizer, an analyzer and the like. The electronic circuit includes a light source, a light receiving element, a signal processing circuit, and the like.

When linearly polarized light propagates in a medium, a strong magnetic field is applied in a direction parallel to the propagation direction of the light, the light vibration direction is deflected, the deflection angle ψ is proportional to the product of the magnetic induction B and the length d of the light passing through the medium, that is, ψ is VBd, and the proportionality coefficient V is called a verdet constant, and is related to the medium properties and the light wave frequency. The above phenomenon is called faraday magneto-optical effect.

According to ampere-loop law, the integral of the magnetic field strength H generated by the current along any closed curve is equal to the algebraic sum of all currents enclosed by the closed curve,

the fiber current sensor is designed based on ampere loop law and Faraday magneto-optical effect.

4.4.5 Water leakage monitoring Unit

The water leakage detection principle diagram is shown in fig. 8, and the circuit principle of the water leakage detection main board is shown in fig. 9.

The water leakage state monitoring module: electronic seal cabin adopts the water repellent of magnetic coupling rotary seal mode, but water-proof effects can't be controlled, and intelligent robot adopts 300V high-tension electricity at the during operation, if sealed electronic cabin leaks in the course of the work, can cause robot consumer short circuit and can damage the robot even. A water leakage state monitoring sensor is additionally arranged in the electronic sealed cabin, if water leakage of the electronic sealed cabin is detected, the underwater robot is powered off immediately, the underwater robot stops working, and safety of the underwater robot is guaranteed.

The water leakage detection unit adopts a BlueROV kit, when the water leakage probe meets water, the water leakage warning lamp lights red, and the yellow water leakage signal line is pulled high to high level through the water leakage detection circuit, so that the GPIO port of the main control panel of the water leakage detection unit generates high level interruption. Meanwhile, the water leakage detection unit converts the GPIO signal into an RS485 communication protocol through the digital signal conversion unit, so that the data of the water leakage detection sensor can be conveniently read by the bus.

4.5 Power supply Unit

The power supply unit is a R4850G6 DC power supply module, and R4850G6 is a digital rectifying module with high efficiency and high power density and power of 2500W. The input voltage is 85-300 VAC, the rated output voltage is 48VDC, and the rated output current is 50A. The circuit has the advantages of soft start, perfect input and output protection, low noise, capability of being used in parallel and the like. And the functions of monitoring the rectifier module and the load in real time and adjusting the output voltage through a background are realized by adopting the latest power supply monitoring technology.

4.6 illumination and image transfer Module

In the process of controlling the underwater robot by an operator, the underwater robot cannot generate a preset movement result according to a preset control instruction due to complex environments such as reefs, silt and the like at the water bottom, or the robot posture fed back by the sensor unit may have a certain error with an actual state due to the influence of uncertain factors such as ocean currents and the like.

The underwater camera carries out data transmission through the Ethernet, and because underwater light is dim, a better shooting effect is achieved by using an auxiliary light source for lighting in the shooting process of the camera; the brightness control of the lighting unit is controlled by an RS485 bus, and different brightness of the lighting lamp can be set through the bus. The underwater real-time external environment information is provided for operators through illumination and an underwater camera, so that the operators can more conveniently control the operation of the underwater robot.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the embodiments of the present invention and not for limiting, and although the embodiments of the present invention are described in detail with reference to the above preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the embodiments of the present invention without departing from the spirit and scope of the technical solutions of the embodiments of the present invention.