Underwater vehicle with force feedback mechanical arm

Abstract

The invention discloses an underwater vehicle with a force feedback mechanical arm. The underwater vehicle comprises an upper shell, a mainboard, a lower shell, an electronic sealed cabin, a multi-degree-of-freedom mechanical arm, a ducted propeller and a current feedback module, wherein the electronic sealed cabin is embedded in the mainboard; the ducted propellers are fixedly connected with the main board and the lower shell respectively; the current feedback module is coaxially nested with a connecting piece of the multi-degree-of-freedom mechanical arm, and the sensing module, the control module and the energy and power module are arranged in the electronic sealed cabin in a layered mode and used for collecting external data and executing movement actions; the multi-degree-of-freedom mechanical arm comprises a bottom rotating device, a joint rotating device and a tail end clamping device and is used for achieving force feedback through current detection fed back by the current feedback module. According to the underwater vehicle, flexible clamping of a target object can be achieved, the electrical performance of the tail end executing mechanism is protected, and the force feedback precision and stability are remarkably improved; and the target object can be automatically grabbed.

Description

Technical Field

[0001] The invention belongs to the technical field of underwater robots, and in particular relates to an underwater vehicle with a force feedback mechanical arm. Background Art

[0002] As humans pay more attention to marine resources and marine science research deepens, underwater environment exploration and development activities are becoming more frequent. From marine resource exploration to marine ecosystem research, from submarine archaeology to maintenance of offshore infrastructure, efficient, accurate and multifunctional underwater equipment is required.

[0003] Although traditional underwater vehicles can navigate underwater and obtain environmental data, they face challenges when performing tasks that require precise operations. For example, when collecting deep-sea biological samples or repairing small submarine equipment, it is difficult to complete complex operations such as grabbing and fixing by relying solely on the simple mechanical structure of the vehicle itself.

[0004] Most traditional underwater vehicles cannot provide operators with feedback information about the operating force when performing operational tasks, and it is difficult for operators to accurately judge whether the force applied is appropriate. In underwater environments, this kind of force control is particularly important. Excessive force may damage fragile marine biological samples or delicate seabed equipment, while insufficient force may lead to operational failures, such as slipping when grabbing objects.

[0005] Underwater vehicles with force feedback manipulators have a wide range of applications. In marine biological research, force feedback manipulators can collect samples gently and accurately based on force feedback information, avoiding damage to samples. In marine geological research, manipulators can adjust the operating force based on the hardness of different geological structures through force feedback, so as to better obtain samples or detection data.

[0006] When mining seabed mineral resources, such as collecting manganese nodules, the force feedback manipulator can reasonably adjust the grasping force according to the size and texture of the nodules to improve the collection efficiency and resource recovery rate. For the maintenance of submarine cables, the force feedback function ensures that the cables will not be damaged due to excessive force when handling them. In the marine environment, many areas have high-risk and high-cost manual operation problems, such as the exploration and development of deep-sea hydrothermal areas. Summary of the invention

[0007] In view of the above problems, the present invention aims to provide an underwater vehicle with a force feedback manipulator arm, which can realize precise operation according to preset programs through an advanced force feedback control system without human operation. This not only reduces the risk to personnel, but also enables long-term and uninterrupted operation, providing strong support for the sustainable development and research of marine resources.

[0008] In order to achieve the above object, the present invention adopts the following technical solution.

[0009] The present invention provides an underwater vehicle with a force feedback mechanical arm, comprising an upper shell, a main board, a lower shell, an electronic sealed cabin, a multi-degree-of-freedom mechanical arm, a ducted propeller, and a current feedback module; wherein the electronic sealed cabin is embedded in the main board and wrapped by the upper shell and the lower shell; the ducted propeller is respectively fixedly connected to the main board and the lower shell; the multi-degree-of-freedom mechanical arm is fixedly connected to the lower shell, the current feedback module and the connecting piece of the multi-degree-of-freedom mechanical arm are coaxially nested, and a sensor module, a control module, and an energy and power module are placed in layers inside the electronic sealed cabin, the sensor module comprises an in-cabin sensor and an out-cabin sensor, the in-cabin sensor comprises an air pressure, smoke, temperature, and bus current sensor; the out-cabin sensor comprises a clamping device at the end of the mechanical arm to detect circuit, and one or more of temperature, pressure, and turbidity sensors; the control module includes an image processing and recognition control mainboard, a motion control mainboard, a six-axis attitude sensor and a magnetometer, and relies on communication cables to feed back the information collected from the sensor module to the host computer in real time, so as to realize intelligent monitoring of the environment inside and outside the cabin, and rely on specific algorithms to distribute the power of the ducted thruster; the energy and power module includes a lithium battery pack, a starting circuit and a voltage stabilizing circuit, which are used to collect external data and perform motion actions; the multi-degree-of-freedom robotic arm includes a bottom rotating device, a joint rotating device and an end clamping device, which are used to realize force feedback by current detection fed back by the current feedback module.

[0010] Furthermore, the electronic sealed cabin is composed of a front window, a sealed cabin body and a bottom wire board, and is independently sealed as a whole.

[0011] Furthermore, a binocular camera is provided in the front viewing window for identifying the target object and calculating its spatial position in the multi-degree-of-freedom robotic arm coordinate system using a spatial positioning algorithm, preparing for the multi-degree-of-freedom robotic arm grasping, and transmitting video information back in real time.

[0012] Furthermore, the multi-degree-of-freedom robotic arm uses the spatial position information to perform inverse kinematics solution to obtain the angle distribution of each servo, thereby realizing automatic grasping of the target object.

[0013] Furthermore, the end clamping device of the multi-degree-of-freedom robotic arm is connected to a current feedback module, which determines the clamping force based on the output current, thereby achieving flexible clamping of the target object.

[0014] Furthermore, the head traces of the upper shell and the lower shell are designed using Granville linear equations to achieve efficient drag reduction, and diversion holes are opened to further ensure the stable navigation of the aircraft.

[0015] Furthermore, the ducted propeller includes two horizontal propellers, three vertical propellers and one side propeller, which are used to control the underwater vehicle to perform full-degree-of-freedom movement in front and back, left and right, up and down, and complex movements of rolling, pitching and rolling underwater.

[0016] Furthermore, the underwater vehicle with force feedback manipulator arm relies on the lithium battery pack in the energy and power module to provide power, and relies on a relay to design a starting circuit to control and protect the main circuit.

[0017] Furthermore, the joint rotation device is realized by three waterproof steering gears.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention relates to an underwater vehicle with a force feedback mechanical arm, which has a mechanical arm based on current detection to achieve force feedback. Compared with conventional underwater mechanical arms, it can achieve flexible clamping of target objects, retain the mechanical structure or biological body structure of the object, protect the electrical performance of the end actuator, and extend the service life;

[0020] For the above-mentioned robotic arm that relies on current detection to achieve force feedback, compared with conventional force feedback robotic arms based on piezoresistive or strain pressure sensors, the interference of water pressure on the detection of clamping pressure and the difficulty of software and hardware filtering and data processing are significantly reduced, thereby improving the accuracy and stability of force feedback.

[0021] The present invention includes a binocular camera capable of spatial positioning, which realizes accurate positioning of the spatial position of the target object through an algorithm, and is matched with an inverse kinematics solution algorithm applied to the coordinate system of the spacecraft, so that the robotic arm can automatically grasp the target object while the hull and the object remain relatively stationary. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments or the prior art description:

[0023] Figure 1 It is an overall schematic diagram of an underwater vehicle with a force feedback mechanical arm provided by an embodiment of the present invention.

[0024] Figure 2 It is a bottom view of an underwater vehicle with a force feedback mechanical arm provided by an embodiment of the present invention.

[0025] Figure 3 It is a top view of the underwater vehicle with a force feedback mechanical arm provided by an embodiment of the present invention with the upper shell removed.

[0026] Figure 4It is a schematic diagram of the structure of a mechanical arm of an underwater vehicle with a force feedback mechanical arm provided in an embodiment of the present invention.

[0027] Figure 5 The invention relates to a current sampling circuit for a clamp at the end of a mechanical arm of an underwater vehicle with a force feedback mechanical arm.

[0028] Explanation of the reference numerals: 1. Upper shell; 2. Vertical thruster; 3. Main board; 4. Horizontal thruster; 5. Side thruster; 6. Lower shell; 7. Underwater light; 8. Current sampling module; 9. Multifunctional connector; 10. End clamp; 11. Front window of electronic sealed cabin; 12. Main body of electronic sealed cabin; 13. Diversion hole; 14. Fastening device of electronic sealed cabin; 15. Binocular camera; 16. Two-dimensional gimbal; 17. Internal bracket of electronic sealed cabin; 18. Control module; 19. Waterproof servo; 20. First movable axis; 21. Second movable axis; 22. Rigid connector; 23. Rotating gimbal; 24. Reversing device; 25. Cable fixing hole. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in more detail below with reference to the accompanying drawings, but the present invention is not limited thereto.

[0030] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as "center", "front", "back", "left", "right", "inside" and "outside" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0031] The present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings.

[0032] like Figure 1-3As shown, an embodiment of the present invention provides an underwater vehicle with a force feedback mechanical arm, including an upper shell 1, a main board 3, a lower shell 6, an electronic sealed cabin, a multi-degree-of-freedom mechanical arm, a ducted propeller, and a current feedback module. In some preferred embodiments, the upper shell 1, the main board 3, and the lower shell 6 are all made of high-strength ABS resin 3D printing, and are fastened by hexagon socket screws. The electronic sealed cabin body 12 is embedded in the main board 3 and wrapped by the upper shell 1 and the lower shell 3; the ducted propeller is respectively connected to the main board 3 and the lower shell 6; the multi-degree-of-freedom mechanical arm is fixed to the lower shell 6, and the current feedback module is coaxially nested with the connector of the multi-degree-of-freedom mechanical arm. The sensor module, control module, energy and power module are placed in layers inside the electronic sealed cabin for collecting external data and performing motion actions; the multi-degree-of-freedom mechanical arm includes a bottom rotating device, a joint rotating device, and an end clamping device for realizing force feedback by current detection fed back by the current feedback module.

[0033] The electronic sealed cabin is composed of a front window 11, a sealed cabin body 12 and a bottom wire board. The body is cylindrical and independently sealed. It is connected to an external actuator and a sensing mechanism through a waterproof cable to collect external data and perform motion actions. A binocular camera 15 is provided in the front window 11 to identify the target object and use a spatial positioning algorithm to solve its spatial position in the multi-degree-of-freedom robot arm coordinate system, prepare for the multi-degree-of-freedom robot arm to grasp, and transmit video information back in real time.

[0034] The front, middle and rear ends of the underwater vehicle are respectively provided with one or more vertical thrusters 2 or horizontal thrusters 4, all of which are fixedly connected to the main board 3. A lateral thruster 5 is placed at the bottom of the vehicle, which is connected to the inside of the electronic sealed cabin through the wire board at the bottom of the electronic sealed cabin and is directly controlled by the electronic speed regulator.

[0035] The shell of the underwater vehicle adopts a streamlined design, which can achieve efficient drag reduction. Preferably, the streamlined design calculates the front end trace of the shell according to the Granville linear equation. The upper and lower shells are fixed to the main board by screws, and two high-lumen underwater lights 7 are installed on the head. The bottom is fixedly connected to the multi-degree-of-freedom mechanical arm through a multi-functional connector 9. The joints of the mechanical arm are connected by a multi-functional connector 9 and a U-shaped bracket, which has high mechanical strength. A number of guide holes are evenly distributed on both sides of the upper shell, which presents the characteristics of axisymmetry.

[0036] Further, the multi-degree-of-freedom manipulator has a total of 4 degrees of freedom, which are divided into a bottom rotating device, a joint rotating device and an end clamping device. Among them, the joint rotating device is realized by three waterproof steering gears. Preferably, the multi-degree-of-freedom manipulator includes a bottom rotating device, a rigid support arm 22, a current sampling module 8, an end clamp 10 and various steering gears. The rotating device adopts a rotating platform 23, including a large torque 360-degree digital steering gear and a multifunctional connector 9, which can support the manipulator to rotate in all directions in the horizontal plane. The rotating platform 23 at the bottom of the manipulator is connected to the rigid connector 22 through the first movable shaft 20, the first movable shaft 20 and the second movable shaft 21 are connected through the rigid connector 22, the front end clamp reversing device 24 is realized by a 360-degree rotating steering gear, and is connected to the steering gear where the second movable shaft 21 is located through the multifunctional connector 9, and the opening and closing of the end clamp 10 is realized by the steering gear. Therefore, the manipulator can realize 4-degree-of-freedom operation through the rotating platform 23, the first movable shaft 20, the second movable shaft 21, and the reversing device 24. The roll angle of the end fixture 10 can be achieved through the reversing device 24, and the pitch angle of the end fixture 10 can be achieved through the coordinated cooperation of the first movable axis 20 and the second movable axis 21. Its relative position with the hull can be freely adjusted in a hemispherical space with the robotic arm as the radius.

[0037] Furthermore, the current sampling module 8 is coaxially nested on the rigid connector 22, and the chip and peripheral circuit are sealed with epoxy resin. The front and rear sides are respectively reserved for wire vias, which monitor the current of the end fixture servo in real time and return the detection value to the control module 18 for further logical judgment. The above-mentioned end clamping device is realized by a high-power waterproof servo, and the manipulator's gripping force is detected in real time through the current detection circuit and the filter circuit, which can effectively prevent the structural damage of the object being gripped and the damage to the electrical performance of the servo.

[0038] Taking into account the need for real-time monitoring of current, the servos in the cases of the present invention are all PWM servos, which is convenient for connecting the current sampling circuit in series with the servo power supply circuit, and using M3 vulcanized rubber to collect and watertighten the robot arm signal and power lines.

[0039] The ducted propeller comprises a waterproof motor, a fairing, a motor housing and a propeller; the propeller is fixed on the rotating shaft of the waterproof motor; the structure composed of the waterproof motor, the propeller and the like is fixed in the duct.

[0040] As a further technical solution, the vehicle is controlled by six ducted thrusters to enable it to move with full freedom underwater. Five of the thrusters are respectively fixed to the front, middle and rear ends of the main board to control the vehicle to move forward and backward, float up and dive down, and turn left and right. The bottom thruster is placed horizontally perpendicular to the vehicle's forward direction to control the vehicle's left and right movement.

[0041] As a further technical solution, in order to meet the use requirements of the bottom thruster, the center of gravity of the vehicle is adjusted to the center of the bottom thruster.

[0042] As a further technical solution, the electronic sealed cabin is fixed by the electronic sealed cabin fastening device 14 placed on the lower shell 6 and the main board 3 to ensure that the internal IMU module is always parallel to the horizontal plane of the hull. The sensor module, control module, energy and power module are placed in layers inside the electronic sealed cabin. The bottom wire is sealed by threading bolts and epoxy resin, and the communication and charging interfaces are led out by watertight connectors.

[0043] Furthermore, the above-mentioned sensing module includes in-cabin sensors and out-cabin sensors, the in-cabin sensors include air pressure, smoke, temperature, and bus current sensors; the out-cabin sensors include a robotic arm end clamp detection circuit, and one or more of temperature, pressure, and turbidity sensors.

[0044] Furthermore, the above-mentioned control module includes an image processing and recognition control mainboard, a motion control mainboard, a six-axis attitude sensor and a magnetometer. The information collected from the sensor module is fed back to the host computer in real time via communication cables, thereby realizing intelligent monitoring of the indoor and outdoor environments and allocating thruster power based on specific algorithms.

[0045] Furthermore, the energy and power module includes a lithium battery pack, a starting circuit and a voltage stabilizing circuit. In a specific embodiment, the lithium battery pack is placed in the lower layer of the internal bracket 17 of the electronic sealed cabin, and participates in adjusting the counterweight parameters of the hull as part of the counterweight. The electronic sealed cabin has two modes: soft start and hard start, wherein the hard start is achieved by the waterproof knob switch at the bottom of the electronic sealed cabin, and the soft start is achieved by sending control and release control signals from the ground station. The hard start circuit of the aircraft includes a knob switch, a normally closed relay and a voltage stabilizing module, the lithium battery pack is electrically connected to the knob switch and the relay control pin, wherein the relay voltage stabilizing module is connected in series to filter out the spike, and the on and off of the relay circuit is controlled, that is, the opening and closing of the relay is used to control the on and off of the main circuit. The circuit protection function is realized by decoupling control of the starting circuit and the main circuit, and the effect of weaker electricity controlling stronger electricity can be achieved.

[0046] Furthermore, the soft start mode corresponds to the hard start mode, that is, the control or release command is issued to the aircraft through the remote control button, so as to quickly restore the original working state after a short power failure, and save electricity. In a preferred embodiment, the electronic sealed cabin adopts a layered modular design, and the integrated processing module of the external sensing device, the power distribution and control module, the power supply module, the electronic speed regulator, and the necessary conditioning circuits and filtering circuits are orderly placed inside the electronic sealed cabin.

[0047] Furthermore, the binocular camera 15 and its two-dimensional gimbal 16 are placed in the front window 11 of the head of the electronic sealed cabin, and rely on image processing algorithms and visual recognition technology to accurately identify the target object, rely on spatial positioning technology to accurately calculate and fuzzy estimate the position information and volume information of the target object, and rely on the main control unit to cooperate with the robotic arm to realize automatic grasping of the target object.

[0048] Furthermore, the main control unit can make a logical judgment on whether to clamp or not through the opening and closing angle of the clamp at the end of the robot arm and the magnitude of the detection current. If the clamping fails for many times, an audible and visual prompt will be sent to the upper computer to request the driver to manually intervene in the control. If the clamping is successful, an audible and visual prompt different from the above description will be sent to the upper computer to request the operator to manually retract the robot arm.

[0049] Furthermore, during the automatic grasping process of the robotic arm, the operator can intervene in manual control at any time.

[0050] In some specific embodiments, when the target object is affected by the water flow and produces a small and slow disturbance, the hull can automatically adjust the navigation attitude and position through the video information sent back by the binocular camera 15 to ensure that the hull and the target object are relatively still.

[0051] In some specific embodiments, when the target object and the hull move relative to each other, the two-dimensional gimbal can automatically track the target object to ensure that the target object is always within the field of view.

[0052] The specific technical details and working principle of an underwater vehicle with a force feedback mechanical arm provided by the present invention are as follows:

[0053] Current detection circuit:

[0054] The current sampling module 8 is coaxially nested with the rigid connector 22. Preferably, the internal detection circuit thereof uses the low-end current detection circuit as the basic circuit. Figure 5 As shown, the current loop to be measured is formed by connecting the H1 terminal and the current sensing resistor R1 in series, wherein the H1 terminal is directly connected to the load and the power supply port, and the resistor R1 is directly connected to the ground. The components R2, C1, and R3 together form an RCR filter circuit to filter out clutter at the input end of the operational amplifier U1. In this embodiment, the operational amplifier U1 uses the chip INA213.

[0055] Furthermore, the positive pole of the operational amplifier U1 is connected to a 5V power supply, the negative pole and the reference voltage are grounded, and filter capacitors C2 and C3 are connected in parallel between the positive and negative poles to filter out high-frequency and low-frequency noise between the positive and negative poles. Under normal working conditions, the operational amplifier INA213 outputs the voltage between IN+ and IN- at 50 times the OUT pin.

[0056] Furthermore, the voltage signal output by the operational amplifier U1 is directly connected to the voltage follower composed of the operational amplifier U2.1 and its peripheral circuits to reduce the output impedance, increase the input impedance, and ensure that the single-chip sampling circuit can completely collect the waveform. The positive and negative electrodes of the operational amplifier U2.1 are connected in parallel with capacitors C4 and C5 to form a filter structure similar to C2 and C3 to filter out high-frequency and low-frequency noise between the positive and negative electrodes.

[0057] Furthermore, the voltage signal output by U2.1 is directly connected to the RC filter circuit composed of R4 and C6 to further filter out noise, and a diode D1 is connected in parallel across capacitor C6 to conduct the abnormal negative voltage signal to the ground, thereby avoiding abnormal errors caused by over-range in the sampling microcontroller.

[0058] Furthermore, the single chip microcomputer uses AD conversion to obtain a voltage value across R1 that is amplified 50 times. In this embodiment, R1 is set to 0.02Ω so that the current value flowing through the load can be directly read.

[0059] As a preference, due to the large current changes when the servo is working, the single-chip computer should perform mean filtering after sampling. In the automatic clamping mode, if the current is detected to reach the threshold, the working state of the end clamp is locked to avoid further clamping and damage to the clamp; in the manual clamping mode, if the current peak value is detected to continuously exceed the set threshold, an audible and visual alarm is sent to the upper computer and the working state of the end clamp is locked until the driver unlocks it.

[0060] It should be understood that the resistor values ​​and operational amplifier selection in the above description are only used to further illustrate the present invention, and are not used to limit the present invention.

[0061] Binocular camera spatial positioning:

[0062] The binocular camera 15 is fixedly connected to the two-dimensional pan-tilt platform 16 and placed together inside the front window 11 of the electronic sealed cabin. Preferably, the same type of distortion-free camera is used and the optical centers of the cameras are placed on the same horizontal line. The process of three-dimensional spatial positioning is as follows:

[0063] (1) As a preferred method, MATLAB is used to adjust the parameters of the two cameras to obtain the intrinsic parameter matrix and the extrinsic parameter matrix respectively. The former includes fx, fy, cx, cy of the left and right cameras, and the latter includes the rotation matrix and translation vector of the left camera relative to the right camera. In this embodiment, the method of intrinsic parameter adjustment is Zhang Youzheng calibration method.

[0064] (2) As a preferred method, the parameter setting results are imported into OpenCV, and the disparity map is calculated using the SGBM algorithm.

[0065] (3) Use two disparity maps to calculate the distance of the target object. The formula is as follows:

[0066]

[0067] Among them, f is the focal length of the camera, b is the distance between the optical centers of the two cameras, d is the parallax, and c is the distance between the two cameras. xr With c xl are the column coordinates of the two camera principal points.

[0068] (4) The spatial position information of the target object in the camera coordinate system can be obtained by the distance between the target object and the binocular camera. The formula is as follows:

[0069]

[0070] Wherein, x and y are the projection coordinates of the target object in a certain camera. In this embodiment, x0 and y0 are both 0.

[0071] (5) The spatial position information of the target object in the robot arm coordinate system can be obtained by translating the coordinate system, and then the target object can be grasped by using inverse kinematics solution.

[0072] Furthermore, the inverse kinematics solution is to obtain a feasible solution for the rotation angle of each movable axis according to the spatial position of the target object in the robot arm coordinate system, so that the end fixture can reach the target object.

[0073] In this embodiment, a volume estimation algorithm is added. For vertical columnar objects, the horizontal axis coordinate difference of the horizontal point pair at the narrowest points on the left and right sides in the camera coordinate system is calculated; for horizontal columnar objects, the vertical axis coordinate difference of the vertical point pair at the narrowest points on the upper and lower sides in the camera coordinate system is calculated; for spherical objects, the horizontal axis coordinate difference of the horizontal point pair at the widest points on the left and right sides in the camera coordinate system is calculated; if the value is significantly greater than the maximum opening and closing distance of the fixture or it is not one of the above three objects, a warning or prompt message is returned to the ground station and the inverse kinematics solution process is terminated.

[0074] Furthermore, for objects other than the above three types, in order to ensure the reliability of gripping, the main control unit sends sound and light prompts to the host computer, suggesting that the driver intervene in manual control to make the gripping work as accurate as possible.

[0075] Image processing and target recognition:

[0076] In this embodiment, the main control unit for image processing and target recognition can be Jetson Nano, which is equipped with a quad-core Cortex-A57 processor, a 128-core Maxwell GPU and 4GB LPDDR memory, which can provide sufficient AI computing power for robot terminals and industrial vision terminals.

[0077] The image processing algorithm includes mean filtering, bilateral filtering, and local histogram equalization. The purpose of the mean filtering is to reduce noise; the purpose of the bilateral filtering is to filter out the tiny complex texture features or noise inside and outside the target object in the image and retain the edge information to the greatest extent; the purpose of the local histogram equalization is to widen the grayscale values ​​of the image with a large number of pixels and merge the grayscale values ​​of the image with a small number of pixels, thereby increasing the contrast and making the image clear.

[0078] The target recognition algorithm in this embodiment adopts the YOLOv5 neural network model, and the marked pictures containing target object information are imported into the downloaded pre-trained model, and recognition can be performed after training.

[0079] Furthermore, the main control JetsonNano obtains the coordinate information of the center of gravity of the target object plane, calculates the coordinate information of the target object in the robot arm coordinate system through the aforementioned spatial positioning algorithm, and sends the inverse kinematics solution result to the robot arm main control unit for execution. At the same time, the host computer synchronously obtains the binocular shooting filtered images and single-channel and three-channel images through the zero buoyancy cable, and annotates the coordinate information and confidence of the target object.

[0080] Appearance design:

[0081] In order to meet the needs of efficient drag reduction, the trajectory of the aircraft head adopts the Granville linear equation, Granville two-parameter square polynomial:

[0082] y 2 =f(x)=r0R(x)+k s1 K s1 (x)+Q(x)

[0083] (0≤x≤1)

[0084] R(x)=2x(x-1) 4

[0085]

[0086] Q(x)=1-(x-1) 4 (4x+1)

[0087] Where r0 represents the radius of curvature at x=0, k s1 represents the rate of change of curvature at x = 1. R(x), K s1 are r0 and k respectively s1 The geometric meaning is the contribution to the y coordinate value, which is related to the fullness of the head. s1The larger it is, the thinner the head of the line is, the fuller the back is, and the curve is more sensitive to the change of r0. For the optimization of the head line, according to the literature, in order to meet the conditions of no inflection point, the reasonable value range of r0 is (0,3.2), k s1 The reasonable value range of is (0,24). In this embodiment, r0=1.2, k s1 =8.

[0088] It should be noted that the above-described embodiments are only preferred embodiments of the present invention. For those skilled in the art, without departing from the principles of the present invention, the present invention may be modified, improved and replaced with equivalents, and these modifications, improvements and equivalents are also considered to fall within the scope of protection of the claims of the present invention.

Claims

1. An underwater vehicle with a force feedback mechanical arm, comprising an upper shell, a main board, and a lower shell, characterized in that: It also includes an electronic sealed cabin, a multi-degree-of-freedom robotic arm, a ducted thruster, and a current feedback module; wherein the electronic sealed cabin is embedded in the main board and is wrapped by the upper shell and the lower shell; the ducted thruster is fixedly connected to the main board and the lower shell respectively; the multi-degree-of-freedom robotic arm is fixedly connected to the lower shell, the current feedback module is coaxially nested with the connector of the multi-degree-of-freedom robotic arm, and the interior of the electronic sealed cabin is layered with a sensor module, a control module, an energy and power module, the sensor module includes an in-cabin sensor and an out-of-cabin sensor, the in-cabin sensor includes an air pressure, smoke, temperature, and bus current sensor; the out-of-cabin sensor includes a clamping device at the end of the robotic arm to detect current circuit, and one or more of temperature, pressure, and turbidity sensors; the control module includes an image processing and recognition control mainboard, a motion control mainboard, a six-axis attitude sensor, and a magnetometer, and relies on communication cables to feed back the information collected from the sensor module to the host computer in real time, so as to realize intelligent monitoring of the environment inside and outside the cabin, and rely on specific algorithms to distribute the power of the ducted thruster; the energy and power module includes a lithium battery pack, a starting circuit, and a voltage stabilizing circuit, which are used to collect external data and perform motion actions; the multi-degree-of-freedom robotic arm includes a bottom rotating device, a joint rotating device, and an end clamping device, which are used to realize force feedback by relying on the current detection fed back by the current feedback module.

2. The underwater vehicle with force feedback mechanical arm according to claim 1, characterized in that: The electronic sealed cabin is composed of a front viewing window, a sealed cabin body and a bottom wire board, and is independently sealed as a whole.

3. The underwater vehicle with force feedback mechanical arm according to claim 2, characterized in that: A binocular camera is provided in the front viewing window for identifying the target object and calculating its spatial position in the multi-DOF robotic arm coordinate system using a spatial positioning algorithm, preparing for the multi-DOF robotic arm to grasp the object, and transmitting video information back in real time.

4. The underwater vehicle with force feedback mechanical arm according to claim 3, characterized in that: The multi-degree-of-freedom mechanical arm uses the spatial position information to perform inverse kinematics solution to obtain the angle distribution of each servo, thereby automatically grasping the target object.

5. The underwater vehicle with force feedback mechanical arm according to claim 1, characterized in that: The end clamping device of the multi-degree-of-freedom robotic arm is connected to the current feedback module, and determines the clamping force based on the output current, thereby achieving flexible clamping of the target object.

6. The underwater vehicle with force feedback mechanical arm according to claim 1, characterized in that: The head traces of the upper shell and the lower shell are designed using Granville linear equations to achieve efficient drag reduction, and diversion holes are opened to further ensure the stable navigation of the aircraft.

7. The underwater vehicle with force feedback mechanical arm according to claim 1, characterized in that: The ducted propeller includes two horizontal propellers, three vertical propellers and one side propeller, which are used to control the underwater vehicle to move with full freedom in the front and back, left and right, up and down directions, as well as complex movements such as rolling, pitching and rolling.

8. The underwater vehicle with force feedback mechanical arm according to claim 1, characterized in that: A waterproof knob switch is provided at the bottom of the electronic sealed cabin. The electronic sealed cabin has two modes: soft start and hard start. The hard start is achieved through the waterproof knob switch, and the soft start is achieved by sending control and release control signals from the ground station.

9. The underwater vehicle with force feedback mechanical arm according to claim 1, characterized in that: The underwater vehicle with force feedback manipulator arm relies on the lithium battery pack in the energy and power module for power supply, and relies on a relay to design a starting circuit to control and protect the main circuit.

10. The underwater vehicle with force feedback mechanical arm according to claim 1, characterized in that: The joint rotation device is realized by three waterproof steering gears.

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