An underwater robot capable of capturing multiple ocean energy sources and a method of operation thereof

Abstract

The present application relates to a kind of underwater robot capable of capturing multiple marine energy and its working method, underwater robot includes the head joint, intermediate joint, buoyancy adjustment joint and tail joint connected in sequence, wherein, head joint includes head shell, forward-looking sonar, negative pressure suction mechanism, two-degree-of-freedom pectoral fin mechanism, passive rotating impeller tidal energy capture mechanism, CTD sensor and side-scan sonar, forward-looking sonar is provided in head shell, the bottom of head shell is provided with negative pressure suction mechanism, passive rotating impeller tidal energy capture mechanism, CTD sensor and side-scan sonar are provided in head shell, two-degree-of-freedom pectoral fin mechanism is provided on the both sides of head shell, and intermediate joint is connected to the other end of head shell.The present application realizes the integration of multiple-source energy capture and movement drive control, can capture marine energy to power underwater robot, can also control underwater robot movement, break the energy supply to the endurance and working time limit of underwater robot.

Description

Technical Field

[0001] This invention relates to an underwater robot capable of capturing various marine energy sources and its operating method, belonging to the field of underwater robot technology. Background Technology

[0002] Underwater robots are key equipment for effectively safeguarding marine resource development and scientific research activities. Currently, most untethered underwater robots based on propeller propulsion and biomimetic principles rely primarily on internal battery systems for energy. However, propulsion via motor-driven propellers or continuous oscillation via biomimetic mechanisms often consumes energy quickly, and existing battery capacity is insufficient to support long-term power supply and operation of underwater robots.

[0003] Ocean-based new energy sources are a crucial breakthrough for achieving long-term self-sustaining operation and maintenance of underwater robots, and therefore have attracted much attention. In recent years, some novel ideas for using ocean energy power generation devices to power underwater robots have been proposed. Chinese patent document CN115571263B discloses an ocean observation wave energy glider that relies on clean and renewable wave energy as a power source for forward navigation to overcome the limitation of limited energy carried by the equipment. Chinese patent document CN110371277B discloses a buoyancy adjustment system for deep-sea equipment and its working method. This system uses the pressure energy of seawater to generate electricity to power deep-sea equipment and extend the equipment's working time. Chinese patent document CN113548146B discloses a self-powered underwater robot based on tidal energy. This device can utilize tidal energy by controlling the extension and retraction of the impeller, while ensuring that the underwater robot's navigation is not affected. However, with the increasing complexity of marine operations, underwater robots need to have the ability to operate for long periods of time, under multiple conditions, and over a wide area. The level of energy supply directly determines the endurance and operational capabilities of underwater robots. A single energy source is insufficient to meet the power supply needs of underwater robots. Therefore, a technical solution to this problem is urgently needed. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an underwater robot capable of capturing multiple types of marine energy. It utilizes three green energy sources—surface wave energy, deep-sea current energy, and profile pressure difference energy—to power the underwater robot. Leveraging the advantage of the flat, slender eel structure for easy energy capture, a biomimetic multi-jointed underwater robot is designed with the ability to capture wave energy, current energy, and pressure difference energy. This achieves integrated coordination of multi-source energy capture and motion control, enabling the underwater robot to both capture marine energy to power its power supply and control its movement, thus overcoming the limitations of energy supply on the underwater robot's endurance and working time.

[0005] The present invention also provides a method for operating the underwater robot capable of capturing various marine energy sources.

[0006] The technical solution of the present invention is as follows:

[0007] An underwater robot capable of capturing various marine energy sources includes a head joint, a middle joint, a buoyancy adjustment joint, and a tail joint connected in sequence.

[0008] The head joint comprises a head shell, forward-looking sonar, negative pressure adsorption mechanism, control system, two-degree-of-freedom pectoral fin mechanism, passive rotating impeller tidal energy harvesting mechanism, CTD sensor, and side-scan sonar. One end of the head shell is conical, housing the forward-looking sonar. The bottom of the head shell houses the negative pressure adsorption mechanism, and within the head shell are the control system, passive rotating impeller tidal energy harvesting mechanism, CTD sensor, and side-scan sonar. Two-degree-of-freedom pectoral fin mechanisms are located on both sides of the head shell. The other end of the head shell is connected to a central joint. The forward-looking sonar, negative pressure adsorption mechanism, two-degree-of-freedom pectoral fin mechanism, passive rotating impeller tidal energy harvesting mechanism, CTD sensor, and side-scan sonar are all connected to the control system. The control system transmits data with surface vessels via an antenna.

[0009] According to a preferred embodiment of the present invention, the negative pressure adsorption mechanism includes a centrifugal pump, a rotary motor, a negative pressure chamber, a rotating shaft, fixing clips, and a suction cup. The centrifugal pump is disposed inside the head shell, and its outlet pipe extends to the outside of the head shell. The inlet pipe of the centrifugal pump is connected to the negative pressure chamber disposed on the outside of the head shell. The suction cup is connected to the negative pressure chamber via a rotating shaft with a cavity. The other side of the suction cup is connected to the output shaft of the rotary motor, which is fixed to the head shell. Rectangular block-shaped fixing clips are respectively provided at the connection points between the output shaft of the rotary motor and the rotating shaft and the suction cup to limit the rotation range of the suction cup. The rotary motor drives the suction cup to rotate along the rotating shaft to adjust the angle. The centrifugal pump, in conjunction with the negative pressure chamber, draws in negative pressure, and the suction cup controls the underwater robot to actively adsorb onto seabed structures.

[0010] According to a preferred embodiment of the present invention, the two-degree-of-freedom pectoral fin mechanism includes a left pectoral fin mechanism and a right pectoral fin mechanism. The left and right pectoral fin mechanisms have identical structures. The left pectoral fin mechanism is connected to the right pectoral fin mechanism via a servo motor mounting plate. The left pectoral fin mechanism includes a first pectoral fin servo, a servo motor connecting plate, a second pectoral fin servo, and a pectoral fin swing plate. The pectoral fin swing plate is disposed on the output shaft of the first pectoral fin servo. The first pectoral fin servo is connected to the second pectoral fin servo via the servo motor connecting plate. The second pectoral fin servo is fixed to the servo motor mounting plate, which is fixed inside the head shell. The pectoral fin swing plate is disposed outside the head shell. The first pectoral fin servo, the servo motor connecting plate, and the second pectoral fin servo are disposed inside the head shell. The two-degree-of-freedom pectoral fin mechanism provides pitch and roll, which can assist the underwater robot in adjusting its motion attitude or suppressing wave drift, providing virtual constraints.

[0011] According to a preferred embodiment of the present invention, the passive rotating impeller tidal energy capture mechanism includes a generator, a telescopic pitch control mechanism, and a passive rotating impeller. The generator is fixed inside the head shell and is connected to the passive rotating impeller via the telescopic pitch control mechanism. The telescopic pitch control mechanism can extend the passive rotating impeller outside the head shell. Deep-sea currents cause the passive rotating impeller to rotate and perform work, thereby converting the current energy into mechanical energy. The generator then converts the mechanical energy into electrical energy. The passive rotating impeller tidal energy capture mechanism, in conjunction with a negative pressure adsorption mechanism, adaptively adjusts the convection direction to capture current energy for auxiliary power supply. The main function of the telescopic pitch control mechanism of the present invention is to control the extension and retraction of the passive rotating impeller, and, in conjunction with the generator and the passive rotating impeller, achieve current energy capture and power generation. The telescopic pitch control mechanism adopts a single-cylinder gear and rack multi-stage telescopic mechanism disclosed in Chinese patent document CN110775858B, employing a two-stage telescopic mechanism. An internal small linear motor is used as the drive device. The first telescopic arm is directly connected to the drive device, and the second telescopic arm is connected to the passive rotating impeller, achieving adjustable telescopic extension.

[0012] According to a preferred embodiment of the present invention, the intermediate joint includes an intermediate outer shell and a center of gravity adjustment mechanism. The center of gravity adjustment mechanism is disposed within the intermediate outer shell and is connected to a control system. One end of the intermediate outer shell is connected to a head joint via a two-degree-of-freedom joint mechanism, and the other end is connected to a buoyancy adjustment joint via a two-degree-of-freedom joint mechanism. The center of gravity adjustment mechanism is an existing mechanism, consisting of a small lead screw motor slide and a counterweight. The counterweight is fixed to the movable slide of the lead screw motor slide. As the motor drives the slide to move, the counterweight fixed thereto changes its relative position with the body, thereby adjusting the center of gravity. Chinese patent documents CN115871903B and CN115071933A disclose underwater robots that both use this mechanism to adjust the device's center of gravity.

[0013] According to a preferred embodiment of the present invention, the buoyancy adjustment joint includes a buoyancy adjustment outer shell, a buoyancy oil bladder, an accumulator, a three-position four-way electro-hydraulic valve, and a booster cylinder. The buoyancy oil bladder is provided on the two-degree-of-freedom joint mechanism connecting the buoyancy adjustment outer shell and the intermediate outer shell. The buoyancy oil bladder is connected to the accumulator via the three-position four-way electro-hydraulic valve. The two ends of the booster cylinder are respectively connected to the three-position four-way electro-hydraulic valve and the outer buoyancy oil bladder. The accumulator, the three-position four-way electro-hydraulic valve, and the booster cylinder constitute the buoyancy adjustment mechanism. The accumulator, the three-position four-way electro-hydraulic valve, and the booster cylinder are all connected to a control system.

[0014] The three-position four-way electro-hydraulic valve in the buoyancy adjustment mechanism controls the accumulator to fill or draw oil into the buoyancy bladder, causing it to expand or contract. When the accumulator fills the buoyancy bladder, it expands, increasing the underwater robot's displacement volume. With buoyancy exceeding gravity, the robot rises to the surface. When the accumulator draws oil from the buoyancy bladder, it contracts, with gravity exceeding buoyancy, causing the robot to descend. As the diving depth increases, when the ambient pressure exceeds the hydraulic accumulator pressure, the booster cylinder pressurizes the accumulator, increasing the effective surface area of ​​the oil and enhancing the output force, achieving low-energy, effective buoyancy drive. When buoyancy and gravity are balanced, the robot hovers.

[0015] According to a preferred embodiment of the present invention, the tail joint includes a tail shell and a hydrophone. The hydrophone is disposed inside the tail shell, and the tail shell is connected to a buoyancy adjustment joint via a two-degree-of-freedom joint mechanism. The hydrophone is connected to a control system.

[0016] According to a preferred embodiment of the present invention, the two-degree-of-freedom joint mechanism includes a front degree-of-freedom joint and a rear degree-of-freedom joint. The front degree-of-freedom joint and the rear degree-of-freedom joint have the same structure. The front degree-of-freedom joint includes an inter-joint connecting block, a front irregular fixed block A, a front irregular fixed block B, a fixed base, a generator-motor integrated machine A, a spur gear, a double gear, and a half gear. The fixed base, the front irregular fixed block A, and the front irregular fixed block B are provided on one side of the inter-joint connecting block. The fixed base is a C-type base. The generator-motor integrated machine A is provided inside the fixed base. A spur gear is provided on the output shaft of the generator-motor integrated machine A. The spur gear is connected to the half gear through the double gear. The double gear and the half gear are respectively provided in the fixed base through gear shaft A and gear shaft B. The gear shafts B of the front degree-of-freedom joint and the rear degree-of-freedom joint are connected at 90° angles. Rubber sleeves are provided on the outer sides of the front degree-of-freedom joint and the rear degree-of-freedom joint.

[0017] When the underwater robot moves actively, the generator-electric integrated unit A operates in motor mode, actively driving the joints to rotate around the two-half gear shaft, allowing the underwater robot to swim like an eel-like fish. When the underwater robot floats to the surface, the generator-electric integrated unit A operates in generator mode, using wave energy to generate electricity. The two-degree-of-freedom joints can have relative movement in both the horizontal and vertical directions. When waves pass by, the various body sections of the underwater robot will rise and fall with the waves. The up-and-down and lateral movements at the joints will cause the generator shaft to rotate through gear transmission, thereby generating electricity.

[0018] According to a preferred embodiment of the present invention, buoyancy material is provided in the head joint, intermediate joint, buoyancy adjustment joint and tail joint.

[0019] The operation and maintenance solution for ocean energy capture and application includes two aspects. For wave energy capture, on the one hand, it controls the underwater robot's drift trajectory on the ocean surface by adjusting the two-degree-of-freedom pectoral fin mechanism, achieving virtual constraint; on the other hand, it controls the underwater robot's gliding descent trajectory, enabling the underwater robot to actively return to its position and continue operations. For ocean current energy capture, a negative pressure adsorption mechanism adheres to the seabed structure, adjusting the convection direction and roll angle of the robot to reduce fluid resistance and improve adsorption reliability, thus achieving energy conversion in conjunction with the ocean current energy capture mechanism. For pressure difference energy capture, a buoyancy adjustment mechanism adjusts the volume of the buoyancy oil bladder in direct contact with seawater, changing the buoyancy of the underwater robot and generating a driving force to assist in its ascent or descent. Simultaneously, when the pressure difference energy within the accumulator performs work, the effective surface area of ​​the oil within the accumulator is increased, enhancing the force and achieving low-energy-consumption, effective buoyancy drive. In deep-sea environments where the pressure is greater than the accumulator pressure, this system acts as a pressurizer, increasing the effective surface area of ​​the oil within the accumulator and enhancing the output force. The entire hydraulic circuit controls the intake and discharge of hydraulic oil into the buoyancy bladder via an accumulator, thereby changing its displacement volume and utilizing pressure difference energy to perform work, thus achieving low-energy-consumption and efficient buoyancy drive. The underwater robot captures various marine energy sources, including surface wave energy, deep-sea current energy, and profile pressure difference energy, to achieve autonomous power supply and long-term operation. Each energy harvesting device in the system can be operated and maintained independently, reducing the impact of energy harvesting on the underwater robot's performance and improving energy supply efficiency.

[0020] The working method of the underwater robot capable of capturing various marine energy sources described above involves the following steps:

[0021] (1) When the underwater robot lies horizontally on the sea surface, under the excitation of waves, the relative motion between the head joint, the middle joint, the buoyancy adjustment joint and the tail joint occurs, driving the half gear of the two-degree-of-freedom joint mechanism to move, which in turn drives the generator A to generate electricity, converting wave energy into electrical energy. During the wave energy supply process, the underwater robot achieves low-energy virtual constraint through the swing angle of the two-degree-of-freedom pectoral fin mechanism, improving the wave energy capture effect and suppressing the underwater robot's drift with the waves.

[0022] (2) Ocean current energy capture process: The head joint of the underwater robot is attached to the underwater fixed object through the negative pressure adsorption mechanism. The centrifugal pump extracts the liquid between the suction cup and the fixed object on the seabed, so that the suction cup and the fixed object on the seabed are attracted. The rotary motor drives the rotating shaft to rotate, which in turn drives the suction cup to rotate and adjust the angle to adapt to the direction of the ocean current. Then the telescopic adjustment mechanism moves the passive rotating impeller outside the head joint. The deep ocean current drives the passive rotating impeller to do work, converting ocean current energy into mechanical energy, which is then converted into electrical energy through the generator to realize ocean current energy power generation.

[0023] (3) Pressure difference energy capture process: The underwater robot dives and monitors the water depth through the airborne CTD sensor during the dive. It also detects the complex seabed structure area through the side-scan sonar and forward-looking sonar. The underwater robot is in a state of slight negative buoyancy during the dive and the body accelerates down. When the specified water depth is reached, the buoyancy of the body increases as the seawater density increases and the body is neutrally suspended. At this time, the three-position four-way electro-hydraulic valve in the buoyancy adjustment mechanism is opened. The pressure difference between the deep seawater and the surface seawater is used to make the buoyancy oil bladder contract to capture the pressure difference energy and store the pressure difference energy in the accumulator in the form of high-pressure hydraulic oil. When the pressure difference energy in the accumulator is used, the pressure cylinder increases the working area of ​​the hydraulic oil in the accumulator to amplify the output force by multiple times, so that the accumulated pressure difference energy can effectively do work in the high-pressure environment of the deep sea.

[0024] The beneficial effects of this invention are as follows:

[0025] 1. This invention uses three green energy sources—ocean surface wave energy, deep-sea current energy, and profile pressure difference energy—to power underwater robots. Taking advantage of the flat and slender eel structure's ability to capture energy, a biomimetic multi-jointed underwater robot with the ability to capture wave energy, current energy, and pressure difference energy is designed. This achieves integrated coordination of multi-source energy capture and motion control, enabling the capture of ocean energy to power the underwater robot and control its movement, thus breaking through the limitations of energy supply on the underwater robot's endurance and working time.

[0026] 2. The underwater robot of this invention integrates multi-source energy harvesting capability and flexible maneuverability, enabling it to perform comprehensive three-dimensional marine survey tasks. This lays the foundation for building a reliable operation and maintenance mechanism for underwater robots with multi-source power supply for comprehensive marine survey tasks, as well as for the practical application of marine energy in complex operational scenarios. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the present invention;

[0028] Figure 2 This is a schematic diagram of the head joint structure of the present invention;

[0029] Figure 3 This is a schematic diagram of the tail joint structure of the present invention.

[0030] Figure 4 This is a schematic diagram of the negative pressure adsorption mechanism of the present invention;

[0031] Figure 5 This is a schematic diagram of the two-degree-of-freedom pectoral fin mechanism of the present invention;

[0032] Figure 6 This invention relates to a passive rotating impeller tidal energy capture mechanism.

[0033] Figure 7This is a schematic diagram of the two-degree-of-freedom joint mechanism of the present invention;

[0034] Figure 8 This is a schematic diagram of the operation and maintenance solution of the present invention;

[0035] Figure 9 This is a schematic diagram of the accumulator working circuit of the buoyancy adjustment mechanism of the present invention;

[0036] Figure 10 This is a schematic diagram of the working state of the present invention;

[0037] Among them: 1-Forward-looking sonar; 2-Negative pressure adsorption mechanism; 3-Control system; 4-Two-degree-of-freedom pectoral fin mechanism; 5-Passive rotating impeller tidal energy capture mechanism; 6-CTD sensor; 7-Side scan sonar; 8-Two-degree-of-freedom joint mechanism; 9-Center of gravity adjustment mechanism; 10-Buoyancy oil bladder; 11-Buoyancy adjustment mechanism; 12-Hydrophone; 13-Floating material; 14-Tail shell; 15-Head joint; 16-Intermediate joint; 17-Buoyancy adjustment joint; 18-Tail joint;

[0038] 201-Centrifugal pump, 202-Negative pressure chamber, 203-Shaft, 204-Fixing buckle, 205-Suction cup; 206-Rotary motor;

[0039] 401-First pectoral fin servo, 402-Servo connecting plate, 403-Servo mounting plate, 404-Pectoral fin swing plate, 405-Second pectoral fin servo;

[0040] 501 - Generator, 502 - Telescopic pitch control mechanism, 503 - Passive rotating impeller;

[0041] 801-Inter-joint connecting block, 802-Front irregular fixed block A, 803-Front irregular fixed block B, 804-Spur gear, 805-Generator-motor integrated unit A, 806-Gear shaft A, 807-Double gear, 808-Half gear, 809-Gear shaft B, 810-Rubber sleeve, 811-Fixed base, 812-Generator-motor integrated unit B, 813-Rear irregular fixed block A, 814-Rear irregular fixed block B;

[0042] 1101-Accumulator, 1102-Three-position four-way electro-hydraulic valve, 1103-Boosting cylinder. Detailed Implementation

[0043] The present invention will be further described below with reference to the embodiments and accompanying drawings, but is not limited thereto. Example 1:

[0044] like Figure 1-7As shown, this embodiment provides an underwater robot capable of capturing various marine energy sources, including a head joint 15, a middle joint 16, a buoyancy adjustment joint 17, and a tail joint 18 connected in sequence.

[0045] The head joint includes a head shell, a forward-looking sonar 1, a negative pressure adsorption mechanism 2, a control system 3, a two-degree-of-freedom pectoral fin mechanism 4, a passive rotating impeller tidal energy capture mechanism 5, a CTD sensor 6, and a side-scan sonar 7. One end of the head shell is conical, and the forward-looking sonar 1 is located inside the conical head shell. The negative pressure adsorption mechanism 2 is located at the bottom of the head shell. The control system 3, the passive rotating impeller tidal energy capture mechanism 5, the CTD sensor 6, and the side-scan sonar 7 are all located inside the head shell. Two-degree-of-freedom pectoral fin mechanisms 4 are located on both sides of the head shell. The other end of the head shell is connected to a middle joint 16. The forward-looking sonar 1, the negative pressure adsorption mechanism 2, the two-degree-of-freedom pectoral fin mechanism 4, the passive rotating impeller tidal energy capture mechanism 5, the CTD sensor 6, and the side-scan sonar 7 are all connected to the control system. The control system transmits data with the surface vessel via an antenna and is also connected to a battery for storing captured electrical energy.

[0046] The negative pressure adsorption mechanism 2 includes a centrifugal pump 201, a rotary motor 206, a negative pressure chamber 202, a rotating shaft 203, fixing buckles 204, and a suction cup 205. The centrifugal pump 201 is located inside the head shell, and its outlet pipe extends to the outside of the head shell. The inlet pipe of the centrifugal pump 201 is connected to the negative pressure chamber 202 located on the outside of the head shell. The negative pressure chamber 202 is connected to the suction cup 205 through the hollow rotating shaft 203. The other side of the suction cup 205 is connected to the output shaft of the rotary motor 206, which is fixed to the head shell. Rectangular block-shaped fixing buckles 204 are respectively provided at the connection points between the rotary motor output shaft and the rotating shaft 203 and the suction cup 205 to limit the rotation range of the suction cup. The rotary motor drives the suction cup to rotate along the rotating shaft to adjust the angle. The centrifugal pump, in conjunction with the negative pressure chamber, draws in negative pressure, and the suction cup controls the underwater robot to actively adsorb onto seabed structures.

[0047] The two-degree-of-freedom pectoral fin mechanism 4 includes a left pectoral fin mechanism and a right pectoral fin mechanism. The left and right pectoral fin mechanisms have the same structure. The left pectoral fin mechanism is connected to the right pectoral fin mechanism through a servo mounting plate 403. The left pectoral fin mechanism includes a first pectoral fin servo 401, a servo connecting plate 402, a second pectoral fin servo 405, and a pectoral fin swing plate 404. The pectoral fin swing plate 404 is provided on the output shaft of the first pectoral fin servo 401. The first pectoral fin servo 401 is connected to the second pectoral fin servo 405 through the servo connecting plate 402. The second pectoral fin servo 405 is fixed to the servo mounting plate 403. The servo mounting plate 403 is fixed inside the head shell. The pectoral fin swing plate 404 is located outside the head shell. The first pectoral fin servo 401, the servo connecting plate, and the second pectoral fin servo 405 are located inside the head shell. The two-DOF pectoral fin mechanism provides pitch and roll, which can help underwater robots adjust their motion posture or suppress wave drift, providing virtual constraints.

[0048] The passive rotating impeller tidal energy capture mechanism 5 includes a generator 501, a telescopic pitch control mechanism 502, and a passive rotating impeller 503. The generator 501 is fixed inside the head shell. The generator 501 is connected to the passive rotating impeller 503 through the telescopic pitch control mechanism 502. The telescopic pitch control mechanism can extend the passive rotating impeller out of the head shell. The deep-sea current energy causes the passive rotating impeller to rotate and do work, thereby converting the current energy into mechanical energy. The generator then converts the mechanical energy into electrical energy. The passive rotating impeller tidal energy capture mechanism, in conjunction with the negative pressure adsorption mechanism, can adaptively adjust the convection direction to capture current energy and provide auxiliary power supply. The main function of the telescopic pitch control mechanism of this invention is to control the extension and retraction of the passive rotating impeller, and to achieve ocean current energy capture and power generation in conjunction with the generator and the passive rotating impeller. The telescopic pitch control mechanism adopts a single-cylinder gear and rack multi-stage telescopic mechanism disclosed in Chinese patent document CN110775858B. It adopts a two-stage telescopic mechanism, and uses a small linear motor (not shown in the figure) as the drive device. The first telescopic arm is directly connected to the drive device, and the second telescopic arm is connected to the passive rotating impeller to achieve telescopic adjustment.

[0049] The intermediate joint 16 includes an intermediate shell and a center of gravity adjustment mechanism 9. The center of gravity adjustment mechanism 9 is housed within the intermediate shell and connected to a control system. One end of the intermediate shell is connected to a head joint 15 via a two-degree-of-freedom joint mechanism 8, and the other end is connected to a buoyancy adjustment joint 17 via the same mechanism. The center of gravity adjustment mechanism is an existing design, consisting of a small lead screw motor slide and a counterweight. The counterweight is fixed to the movable slide of the lead screw motor slide. As the motor drives the slide to move, the counterweight changes its relative position to the body, thus adjusting the center of gravity. Chinese patent documents CN115871903B and CN115071933A disclose underwater robots that use this mechanism to adjust the device's center of gravity.

[0050] The buoyancy adjustment joint 17 includes a buoyancy adjustment shell, a buoyancy oil bladder 10, an accumulator 1101, a three-position four-way electro-hydraulic valve 1102, and a booster cylinder 1103. The buoyancy oil bladder 10 is provided on the two-degree-of-freedom joint mechanism connecting the buoyancy adjustment shell and the intermediate shell. The buoyancy oil bladder 10 is connected to the accumulator 1101 through the three-position four-way electro-hydraulic valve 1102. The two ends of the booster cylinder 1103 are respectively connected to the three-position four-way electro-hydraulic valve 1102 and the outer buoyancy oil bladder 10. The accumulator 1101, the three-position four-way electro-hydraulic valve 1102, and the booster cylinder 1103 constitute the buoyancy adjustment mechanism 11. The accumulator 1101, the three-position four-way electro-hydraulic valve 1102, and the booster cylinder 1103 are all connected to a control system.

[0051] The three-position four-way electro-hydraulic valve in the buoyancy adjustment mechanism controls the accumulator to fill or draw oil into the buoyancy bladder, causing it to expand or contract. When the accumulator fills the buoyancy bladder, it expands, increasing the underwater robot's displacement volume. With buoyancy exceeding gravity, the robot rises to the surface. When the accumulator draws oil from the buoyancy bladder, it contracts, with gravity exceeding buoyancy, causing the robot to descend. As the diving depth increases, when the ambient pressure exceeds the hydraulic accumulator pressure, the booster cylinder pressurizes the accumulator, increasing the effective surface area of ​​the oil and enhancing the output force, achieving low-energy, effective buoyancy drive. When buoyancy and gravity are balanced, the robot hovers.

[0052] The tail joint 18 includes a tail shell 14 and a hydrophone 12. The hydrophone is installed inside the tail shell. The tail shell is connected to a buoyancy adjustment joint via a two-degree-of-freedom joint mechanism 8. The hydrophone 12 is connected to a control system.

[0053] The two-degree-of-freedom joint mechanism 8 includes a front degree-of-freedom joint and a rear degree-of-freedom joint. The front degree-of-freedom joint includes an inter-joint connecting block 801, a front irregular fixed block A802, a front irregular fixed block B803, a fixed base 811, a generator-motor integrated machine A805, a spur gear 804, a double gear 807, and a half gear 808. The fixed base 811, the front irregular fixed block A802, and the front irregular fixed block B803 are provided on one side of the inter-joint connecting block 801. The fixed base 811 is a C-shaped base, and the generator-motor integrated machine A805 is installed inside the fixed base 811. The generator-motor integrated machine A805 outputs power... A spur gear 804 is mounted on the output shaft. The spur gear 804 is connected to a half gear 808 via a double gear 807. The double gear 807 and the half gear 808 are respectively mounted in the fixed base 811 via gear shafts A806 and B809. The front and rear degree-of-freedom joints have the same structure. The rear degree-of-freedom joint includes components such as a generator-motor integrated unit B812, a rear irregularly shaped fixing block A813, and a rear irregularly shaped fixing block B814. The gear shafts B of the front and rear degree-of-freedom joints are connected at a 90° angle. Rubber sleeves 810 are provided on the outer sides of the front and rear degree-of-freedom joints.

[0054] When the underwater robot moves actively, the generator-electric integrated unit A operates in motor mode, actively driving the joints to rotate around the two-half gear shaft, allowing the underwater robot to swim like an eel-like fish. When the underwater robot floats to the surface, the generator-electric integrated unit A operates in generator mode, using wave energy to generate electricity. The two-degree-of-freedom joints can have relative movement in both the horizontal and vertical directions. When waves pass by, the various body sections of the underwater robot will rise and fall with the waves. The up-and-down and lateral movements at the joints will cause the generator shaft to rotate through gear transmission, thereby generating electricity.

[0055] Operation and maintenance solutions for ocean energy capture and utilization processes, such as Figure 8 As shown, for the wave energy capture process, on the one hand, the underwater robot's drift trajectory with the waves on the ocean surface is controlled by adjusting the two-degree-of-freedom pectoral fin mechanism to achieve virtual constraint; on the other hand, the underwater robot's gliding and diving trajectory is controlled to enable the underwater robot to actively return to its position and achieve continuous operation. For the ocean current energy capture process, the negative pressure adsorption mechanism adheres to the seabed structure, adjusts the convection direction and roll angle of the body, reduces fluid resistance, improves adsorption reliability, and works with the ocean current energy capture mechanism to achieve energy conversion. For the pressure difference energy capture process, the buoyancy adjustment mechanism adjusts the volume of the buoyancy oil bladder in direct contact with seawater, changing the buoyancy of the underwater robot and generating a driving force to assist in the underwater robot's ascent or descent. At the same time, when the pressure difference energy in the accumulator does work externally, the effective surface area of ​​the oil in the accumulator is increased to increase the force, achieving low-energy-consumption and effective buoyancy drive. In deep-sea environments where the pressure is greater than the accumulator pressure, it acts as a pressurizer, increasing the effective surface area of ​​the oil in the accumulator and increasing the output force. The entire hydraulic circuit controls the intake and discharge of hydraulic oil into the buoyancy bladder via an accumulator, thereby changing its displacement volume and utilizing pressure difference energy to perform work, thus achieving low-energy-consumption and efficient buoyancy drive. The underwater robot captures various marine energy sources, including surface wave energy, deep-sea current energy, and profile pressure difference energy, to achieve autonomous power supply and long-term operation. Each energy harvesting device in the system can be operated and maintained independently, reducing the impact of energy harvesting on the underwater robot's performance and improving energy supply efficiency.

[0056] The above-mentioned underwater robots capable of capturing various marine energy sources operate in ways such as Figure 10 As shown, wave energy is used as the primary energy source, supplemented by pressure difference energy from the pressure difference between shallow and deep seawater and ocean current energy from the relative motion between the body and the seawater. The specific steps are as follows:

[0057] (1) When the underwater robot lies horizontally on the sea surface, under the excitation of waves, the relative motion between the head joint, the middle joint, the buoyancy adjustment joint and the tail joint occurs, driving the half gear of the two-degree-of-freedom joint mechanism to move, which in turn drives the generator A to generate electricity, converting wave energy into electrical energy. During the wave energy supply process, the underwater robot achieves low-energy virtual constraint through the swing angle of the two-degree-of-freedom pectoral fin mechanism, improving the wave energy capture effect and suppressing the underwater robot's drift with the waves.

[0058] (2) Ocean current energy capture process: The head joint of the underwater robot is attached to the underwater fixed object through the negative pressure adsorption mechanism. The centrifugal pump extracts the liquid between the suction cup and the fixed object on the seabed, so that the suction cup and the fixed object on the seabed are attracted. The rotary motor drives the rotating shaft to rotate, which in turn drives the suction cup to rotate and adjust the angle to adapt to the direction of the ocean current. Then the telescopic adjustment mechanism moves the passive rotating impeller outside the head joint. The deep ocean current drives the passive rotating impeller to do work, converting ocean current energy into mechanical energy, which is then converted into electrical energy through the generator to realize ocean current energy power generation.

[0059] (3) Pressure difference energy capture process: The underwater robot dives and monitors the water depth through the airborne CTD sensor during the dive. It also detects the complex seabed structure area through the side-scan sonar and forward-looking sonar. The underwater robot is in a state of slight negative buoyancy during the dive and the body accelerates down. When the specified water depth is reached, the buoyancy of the body increases as the seawater density increases and the body is neutrally suspended. At this time, the three-position four-way electro-hydraulic valve in the buoyancy adjustment mechanism is opened. The pressure difference between the deep seawater and the surface seawater is used to make the buoyancy oil bladder contract to capture the pressure difference energy and store the pressure difference energy in the accumulator in the form of high-pressure hydraulic oil. When the pressure difference energy in the accumulator is used, the pressure cylinder increases the working area of ​​the hydraulic oil in the accumulator to amplify the output force by multiple times, so that the accumulated pressure difference energy can effectively do work in the high-pressure environment of the deep sea. Example 2:

[0060] An underwater robot capable of capturing various marine energy sources has the structure described in Example 1, except that a float material 13 is provided in the head joint, intermediate joint, buoyancy adjustment joint and tail joint.

[0061] The specific embodiments described in this specification may differ in the shape and name of their parts and components. All equivalent or simple variations made to the structure, features, and principles described in this patent concept are included within the scope of protection of this patent. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, as long as they do not depart from the structure of this invention or exceed the scope defined in these claims, all of which should fall within the scope of protection of this invention.

Claims

1. An underwater robot capable of capturing various marine energy sources, characterized in that, This includes the head joint, intermediate joint, buoyancy adjustment joint, and tail joint connected in sequence. The head joint includes a head shell, a forward-looking sonar, a negative pressure adsorption mechanism, a control system, a two-degree-of-freedom pectoral fin mechanism, a passive rotating impeller tidal energy capture mechanism, a CTD sensor, and a side-scan sonar. One end of the head shell is conical, and the forward-looking sonar is installed inside the conical head shell. The negative pressure adsorption mechanism is installed at the bottom of the head shell. The control system, the passive rotating impeller tidal energy capture mechanism, the CTD sensor, and the side-scan sonar are installed inside the head shell. Two-degree-of-freedom pectoral fin mechanisms are installed on both sides of the head shell. The other end of the head shell is connected to an intermediate joint. The forward-looking sonar, the negative pressure adsorption mechanism, the two-degree-of-freedom pectoral fin mechanism, the passive rotating impeller tidal energy capture mechanism, the CTD sensor, and the side-scan sonar are all connected to the control system. The negative pressure adsorption mechanism includes a centrifugal pump, a rotary motor, a negative pressure chamber, a rotating shaft, fixing buckles, and a suction cup. The centrifugal pump is located inside the head housing, and the centrifugal pump outlet pipe extends to the outside of the head housing. The centrifugal pump inlet pipe is connected to the negative pressure chamber located on the outside of the head housing. The negative pressure chamber is connected to the suction cup through the rotating shaft of the cavity. The other side of the suction cup is connected to the output shaft of the rotary motor, which is fixed to the head housing. Rectangular block-shaped fixing buckles are respectively provided at the connection points between the output shaft of the rotary motor and the rotating shaft and the suction cup to limit the rotation range of the suction cup. The two-degree-of-freedom pectoral fin mechanism includes a left pectoral fin mechanism and a right pectoral fin mechanism. The left and right pectoral fin mechanisms have the same structure. The left pectoral fin mechanism is connected to the right pectoral fin mechanism through a servo mounting plate. The left pectoral fin mechanism includes a first pectoral fin servo, a servo connecting plate, a second pectoral fin servo, and a pectoral fin swing plate. The pectoral fin swing plate is provided on the output shaft of the first pectoral fin servo. The first pectoral fin servo is connected to the second pectoral fin servo through the servo connecting plate. The second pectoral fin servo is fixed to the servo mounting plate. The servo mounting plate is fixed inside the head shell. The pectoral fin swing plate is located outside the head shell. The first pectoral fin servo, the servo connecting plate, and the second pectoral fin servo are located inside the head shell. The passive rotating impeller tidal energy capture mechanism includes a generator, a telescopic pitch control mechanism and a passive rotating impeller. The generator is fixed inside the head housing and is connected to the passive rotating impeller through the telescopic pitch control mechanism. One end of the middle shell is connected to a head joint via a two-degree-of-freedom joint mechanism, and the other end is connected to a buoyancy adjustment joint via a two-degree-of-freedom joint mechanism. The two-degree-of-freedom joint mechanism includes a front degree-of-freedom joint and a rear degree-of-freedom joint. The front degree-of-freedom joint and the rear degree-of-freedom joint have the same structure. The front degree-of-freedom joint includes an inter-joint connecting block, a front irregular fixed block A, a front irregular fixed block B, a fixed base, a generator-motor integrated machine A, a spur gear, a double gear, and a half gear. When the underwater robot moves actively, the generator-electric integrated unit A operates in motor mode, actively driving the joints to rotate around the two-half gear shaft, allowing the underwater robot to swim like an eel-like fish. When the underwater robot floats to the surface, the generator-electric integrated unit A operates in generator mode, using wave energy to generate electricity. The two-degree-of-freedom joints can have relative movement in both the horizontal and vertical directions. When waves pass by, the various body sections of the underwater robot will rise and fall with the waves. The up-and-down and lateral movements at the joints will cause the generator shaft to rotate through gear transmission, thereby generating electricity.

2. The underwater robot capable of capturing various marine energy sources as described in claim 1, characterized in that, The intermediate joint includes an intermediate shell and a center of gravity adjustment mechanism. The center of gravity adjustment mechanism is installed inside the intermediate shell and is connected to a control system.

3. The underwater robot capable of capturing various marine energy sources as described in claim 2, characterized in that, The buoyancy adjustment joint includes a buoyancy adjustment shell, a buoyancy oil bladder, an accumulator, a three-position four-way electro-hydraulic valve, and a booster cylinder. The two-degree-of-freedom joint mechanism connecting the buoyancy adjustment shell and the intermediate shell is equipped with a buoyancy oil bladder. The buoyancy oil bladder is connected to the accumulator through the three-position four-way electro-hydraulic valve. The two ends of the booster cylinder are respectively connected to the three-position four-way electro-hydraulic valve and the outer buoyancy oil bladder. The accumulator, the three-position four-way electro-hydraulic valve, and the booster cylinder constitute the buoyancy adjustment mechanism. The accumulator, the three-position four-way electro-hydraulic valve, and the booster cylinder are all connected to a control system.

4. The underwater robot capable of capturing various marine energy sources as described in claim 3, characterized in that, The tail joint includes a tail shell and a hydrophone. The hydrophone is installed inside the tail shell. The tail shell is connected to a buoyancy adjustment joint through a two-degree-of-freedom joint mechanism. The hydrophone is connected to a control system.

5. The underwater robot capable of capturing various marine energy sources as described in claim 4, characterized in that, A fixed base, a front irregular fixed block A, and a front irregular fixed block B are provided on one side of the joint connecting block. The fixed base is a C-type base. A generator-motor integrated machine A is installed inside the fixed base. A spur gear is installed on the output shaft of the generator-motor integrated machine A. The spur gear is connected to a half gear through a double gear. The double gear and the half gear are respectively installed in the fixed base through gear shaft A and gear shaft B. The gear shafts B of the front degree of freedom joint and the rear degree of freedom joint are connected at 90°. Rubber sleeves are provided on the outside of the front degree of freedom joint and the rear degree of freedom joint.

6. The underwater robot capable of capturing various marine energy sources as described in claim 1, characterized in that, The head joint, intermediate joint, buoyancy adjustment joint, and tail joint are all equipped with buoyancy material.

7. The operating method of the underwater robot capable of capturing multiple marine energy sources as described in claim 5, characterized in that, The steps are as follows: (1) When the underwater robot lies horizontally on the sea surface, under the excitation of waves, the relative motion between the head joint, the middle joint, the buoyancy adjustment joint and the tail joint occurs, driving the half gear of the two-degree-of-freedom joint mechanism to move, which in turn drives the generator A to generate electricity, converting wave energy into electrical energy. During the wave energy supply process, the underwater robot achieves low-energy virtual constraint through the swing angle of the two-degree-of-freedom pectoral fin mechanism. (2) Ocean current energy capture process: The head joint of the underwater robot is attached to the underwater fixed object through the negative pressure adsorption mechanism. The centrifugal pump extracts the liquid between the suction cup and the fixed object on the seabed, so that the suction cup and the fixed object on the seabed are attracted. The rotary motor drives the rotating shaft to rotate, which in turn drives the suction cup to rotate and adjust the angle to adapt to the direction of the ocean current. Then the telescopic adjustment mechanism moves the passive rotating impeller outside the head joint. The deep ocean current drives the passive rotating impeller to do work, converting ocean current energy into mechanical energy, which is then converted into electrical energy through the generator to realize ocean current energy power generation. (3) Pressure difference energy capture process: The underwater robot dives and monitors the water depth through the airborne CTD sensor during the dive. It also detects the complex seabed structure area through the side-scan sonar and forward-looking sonar. The underwater robot is in a state of slight negative buoyancy during the dive and the body accelerates down. When the specified water depth is reached, the buoyancy of the body increases as the seawater density increases and the body is neutrally suspended. At this time, the three-position four-way electro-hydraulic valve in the buoyancy adjustment mechanism is opened. The pressure difference between the deep seawater and the surface seawater is used to make the buoyancy oil bladder contract to capture the pressure difference energy and store the pressure difference energy in the accumulator in the form of high-pressure hydraulic oil. When the pressure difference energy in the accumulator is used, the pressure cylinder increases the working area of ​​the hydraulic oil in the accumulator to amplify the output force by multiple times, so that the accumulated pressure difference energy can effectively do work in the high-pressure environment of the deep sea.

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