Swimming pool cleaning robot and floating control method and floating control device thereof

Abstract

The present disclosure provides a pool cleaning robot and its floating control method and device, relating to the technical field of pool cleaning equipment. The device comprises a shell, a closed-cell foam buoyancy element and a driving assembly. The shell is provided with a water communication structure for connecting the inside of the shell with the external water body, and the closed-cell foam buoyancy element is arranged in the shell. When the driving assembly compresses the closed-cell foam buoyancy element, the volume of the closed-cell foam buoyancy element decreases, the external water body enters the shell, and the buoyancy of the robot decreases. When the driving assembly releases the closed-cell foam buoyancy element, the closed-cell foam buoyancy element restores and discharges the water in the shell, and the buoyancy of the robot increases. The technical solution can reduce the noise of gas charging and discharging and the risk of aging and damage of the air bag, reduce the dependence on high-precision dynamic seals, water pumping pipelines and independent water tanks, improve the compactness and long-term floating reliability of the device.

Description

Technical Field

[0001] This disclosure relates to the field of swimming pool cleaning equipment technology, and more specifically, to a swimming pool cleaning robot and its buoyancy control method and buoyancy control device. Background Technology

[0002] With the development of pool cleaning robot technology, pool cleaning robots typically need to perform cleaning operations on the bottom, sidewalls, and waterline of pools. Because different cleaning areas correspond to different water depths and operating postures, pool cleaning robots need to have the ability to actively float, sink, or maintain a position near the target water depth during the cleaning process. Therefore, how to achieve stable and reliable buoyancy control for pool cleaning robots in aquatic environments has become a crucial issue in ensuring that pool cleaning robots can complete multi-area cleaning operations.

[0003] Currently, when controlling the buoyancy of swimming pool cleaning robots, related technologies either require adjusting buoyancy through gas inflation and deflation, which results in significant noise and easy aging and damage to flexible structures; or they require adjusting buoyancy by pumping out pool water or injecting water into independent compartments, which places high demands on sealing and piping structures and is easily affected by debris in the pool water, leading to complex structures, large space occupation, and insufficient long-term operational reliability.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this disclosure is to provide a swimming pool cleaning robot and its buoyancy control method and device, thereby reducing gas inflation and deflation noise and the risk of airbag aging and damage, reducing reliance on high-precision dynamic seals, drainage pipes and independent water tanks, and improving the device's compactness and long-term buoyancy reliability.

[0006] According to a first aspect of the present disclosure, a buoyancy control device for a swimming pool cleaning robot is provided, comprising: a housing, the housing having a water-permeable structure for communicating the interior of the housing with external water; a closed-cell foam buoyancy member disposed within the housing, the closed-cell foam buoyancy member being compressible and recoverable; and a drive assembly, at least partially disposed within the housing, the drive assembly being used to compress or release the closed-cell foam buoyancy member; wherein, when the drive assembly compresses the closed-cell foam buoyancy member, the volume of the closed-cell foam buoyancy member decreases, and external water enters the housing through the water-permeable structure, thereby reducing the buoyancy of the swimming pool cleaning robot; when the drive assembly releases the closed-cell foam buoyancy member, the closed-cell foam buoyancy member recovers and its volume increases, and water inside the housing is discharged through the water-permeable structure, thereby increasing the buoyancy of the swimming pool cleaning robot.

[0007] On the one hand, by using compressible and recoverable closed-cell foamed buoyancy components as the direct object of buoyancy changes, the buoyancy adjustment of the pool cleaning robot no longer relies on the gas inflation and deflation process. The floating and sinking movements can be based on the volume changes of the buoyancy components themselves, thereby reducing the operating noise introduced by the gas inflation and deflation process and lowering the risk of aging, fatigue, or damage to the flexible airbags after long-term immersion and repeated deformation, thus improving the structural reliability of the pool cleaning robot when performing floating and sinking movements over a long period. On the other hand, by connecting the inside of the shell with the external water body and allowing water to enter or exit the shell according to the volume changes of the buoyancy components, the buoyancy adjustment process does not require high-precision sealing of the pool water by a piston cylinder. The closed-loop drainage system eliminates the need for complex injection and drainage pipelines around independent water tanks, thereby reducing the reliance of the buoyancy control device on dynamic sealing structures and sealed chambers. This reduces the possibility of clogging, wear, or seal failure caused by debris such as mud, hair, or leaf fragments in the pool water. Furthermore, by transforming the buoyancy adjustment process into a coordinated process of buoyancy component volume change and water inflow / outflow within the shell, the structure required for buoyancy control can complete buoyancy changes with fewer chambers and pipelines. This reduces the structural complexity and space occupation of the device, improves its adaptability within the body of a small pool cleaning robot, and enhances the stability of the pool cleaning robot's buoyancy movements during cleaning operations in multiple areas such as the bottom, side walls, and waterline.

[0008] In some exemplary embodiments of this disclosure, based on the aforementioned scheme, the closed-cell foam buoyancy component has multiple non-interconnected closed-cell air bubbles formed inside; under the compression action of the driving component, the volume of each closed-cell air bubble is compressed, the closed-cell foam buoyancy component deforms from a first volume to a second volume, and the second volume is smaller than the first volume; and after being released by the driving component, the closed-cell foam buoyancy component recovers from the second volume to the first volume by relying on the elastic expansion force generated by the closed-cell air bubbles during recovery.

[0009] By forming multiple unconnected closed-cell bubbles inside the closed-cell foam buoyancy component, the overall volume of the closed-cell foam buoyancy component is reduced mainly by the volume compression of each closed-cell bubble when under pressure, and the volume is restored by the elastic recovery of the closed-cell bubbles and the material matrix after release. This allows for the formation of a repeatable buoyancy change basis without introducing a gas filling and defilling structure, reducing reliability issues caused by aging and damage of flexible airbags, air leakage failure, and filling and defilling noise, and improving the stability of the float-sink control device in long-term cyclic operation.

[0010] In some example embodiments of this disclosure, based on the foregoing scheme, the compression rate of the closed-cell foamed buoyancy component when it deforms from the first volume to the second volume is 30% to 50%; the volume of water entering or exiting the interior of the shell is related to the volume difference between the first volume and the second volume.

[0011] By setting the compression rate of the closed-cell foam buoyancy component from the first volume to the second volume to 30% to 50%, the closed-cell foam buoyancy component can generate sufficient volume change to drive water into or out of the shell, while avoiding excessive compression that could lead to the collapse of closed-cell bubbles, permanent deformation of the material, or a decrease in its recovery ability. This achieves a balance between the buoyancy adjustment range and the lifespan of the closed-cell foam buoyancy component, thereby improving the controllability and repeatability of the sinking and floating actions of the pool cleaning robot.

[0012] In some example embodiments of this disclosure, based on the foregoing scheme, the driving component includes: a power component; a compression component, wherein the power component is drively connected to the compression component, and the compression component is disposed opposite to the closed-cell foam buoyancy component; wherein, when the power component drives the compression component to move toward the closed-cell foam buoyancy component, the driving component compresses the closed-cell foam buoyancy component, and when the compression component moves away from the closed-cell foam buoyancy component, the driving component releases the closed-cell foam buoyancy component.

[0013] By setting the drive assembly to a structure that combines a power component and a compression component, and by positioning the compression component relative to the closed-cell foam buoyancy component, the output of the power component can be converted into a direct compression or release action on the closed-cell foam buoyancy component via the compression component. This simplifies the drive force transmission path, reduces the gaps, jamming, and response lag caused by the intermediate transmission structure, and improves the directness and consistency of the volume adjustment of the closed-cell foam buoyancy component.

[0014] In some exemplary embodiments of this disclosure, based on the foregoing scheme, the drive assembly further includes a hydraulic lever mechanism, which includes: a first piston; a second piston; and a sealed hydraulic chamber. The sealed hydraulic chamber is used to connect the first piston and the second piston. The sealed hydraulic chamber is isolated from the internal water-passing area of ​​the housing. The hydraulic medium in the sealed hydraulic chamber does not come into contact with external water entering the housing through the water-passing structure. The cross-sectional area of ​​the first piston is smaller than that of the second piston. The power component is used to drive external water into or out of the side of the first piston away from the sealed hydraulic chamber, so as to adjust the hydraulic pressure in the sealed hydraulic chamber through the first piston. The second piston constitutes the compression component, or the second piston is drivenly connected to the compression component.

[0015] By employing a hydraulic lever mechanism consisting of a first piston, a second piston, and a sealed hydraulic chamber, and isolating the sealed hydraulic chamber from the water-permeable area inside the shell, the hydraulic medium within the sealed hydraulic chamber transmits pressure only between the first and second pistons as a closed pressure transmission medium, without contacting external water entering through the water-permeable structure. Simultaneously, a power component drives external water into or out of the side of the first piston away from the sealed hydraulic chamber, causing the external water to drive the first piston. The first piston regulates the hydraulic pressure within the sealed hydraulic chamber, driving the second piston to output the force used to compress the closed-cell foam buoyancy component. This allows the external water to drive the first piston while preventing debris such as mud, hair, and leaf debris from entering the sealed hydraulic chamber, thus avoiding hydraulic medium contamination, piston wear, jamming, or seal failure. Furthermore, the closed hydraulic transmission enables smooth compression of the closed-cell foam buoyancy component, reducing the space and driving capacity requirements of direct mechanical high-thrust structures and improving the operational reliability of the buoyancy control device in long-term aquatic environments.

[0016] In some exemplary embodiments of this disclosure, based on the aforementioned scheme, the ratio of the cross-sectional area of ​​the second piston to the cross-sectional area of ​​the first piston is 1.5:1 to 10:1. When the first piston moves under the action of the hydraulic medium, the second piston compresses the closed-cell foamed buoyancy component with an output thrust greater than the input thrust of the first piston.

[0017] By setting the ratio of the cross-sectional area of ​​the second piston to that of the first piston to be between 1.5:1 and 10:1, the smaller input thrust on the first piston side can be transmitted to the second piston side via hydraulic pressure to form a larger output thrust. This allows the compression requirements of the closed-cell foam buoyancy component to be met even within a pool cleaning robot where the size and power of the power components are limited. At the same time, this ratio range can avoid insufficient force amplification due to an excessively small area difference, and also avoid insufficient stroke of the second piston or excessive structural size due to an excessively large area difference, thus improving the practicality and compactness of the hydraulic force amplification structure.

[0018] In some exemplary embodiments of this disclosure, based on the foregoing scheme, the power component includes a gear pump, which delivers external water to the side of the first piston away from the sealed hydraulic chamber by forward operation and discharges the water from the side of the first piston away from the sealed hydraulic chamber by reverse operation; or, the power component includes a water pump and a reversing valve, which switches the flow direction of the external water relative to the side of the first piston away from the sealed hydraulic chamber through the reversing valve.

[0019] By setting the power component as a gear pump capable of transporting external water in both directions, or as a structure combining a water pump and a reversing valve, the entry and exit of external water relative to the side of the first piston away from the sealed hydraulic chamber can be achieved through pump reversal or valve switching. This provides a clear flow direction control relationship for the reciprocating drive of the first piston, the rise and fall of hydraulic pressure in the sealed hydraulic chamber, and the compression and release of the closed-cell foamed buoyancy component. This configuration can utilize external water to adjust the driving pressure on the first piston side while maintaining the closed pressure transmission state of the hydraulic medium in the sealed hydraulic chamber. This reduces the need for complex mechanical transmission mechanisms or multiple power sources, lowers the risk of external water entering the sealed hydraulic chamber and causing contamination, jamming, or seal failure, and facilitates compact, low-noise, and reliable buoyancy adjustment.

[0020] In some example embodiments of this disclosure, based on the foregoing scheme, the drive assembly further includes: a return spring disposed between the second piston and the closed-cell foam buoyancy member; wherein, when the second piston moves toward the closed-cell foam buoyancy member and compresses the closed-cell foam buoyancy member, the return spring is compressed and stores elastic potential energy; when the hydraulic pressure in the sealed hydraulic chamber decreases, the return spring releases the elastic potential energy to push the second piston to reset and / or assist the closed-cell foam buoyancy member to recover.

[0021] By setting a return spring between the second piston and the closed-cell foam buoyancy component, the return spring synchronously stores elastic potential energy when the second piston compresses the closed-cell foam buoyancy component. After the pressure in the sealed hydraulic chamber decreases, the elastic potential energy is released to push the second piston to reset and / or assist the closed-cell foam buoyancy component to recover. This reduces the risk of the second piston remaining in the compressed position due to sealing friction, residual hydraulic pressure, or guide resistance, reduces permanent deformation caused by long-term pressure on the closed-cell foam buoyancy component, and improves the response speed and recovery reliability of the release action.

[0022] In some exemplary embodiments of this disclosure, based on the foregoing scheme, the closed-cell foam buoyancy component and the drive assembly are both configured as multiple sets, and the multiple sets of the closed-cell foam buoyancy component and the multiple sets of the drive assembly are arranged at intervals along the circumference or axial direction of the pool cleaning robot to synchronously or independently adjust the buoyancy of the pool cleaning robot.

[0023] By setting closed-cell foam buoyancy components and drive components in multiple groups and arranging them at intervals along the circumference or axis of the pool cleaning robot, the buoyancy adjustment effect can be distributed in different areas of the machine body, rather than concentrated in a single position. This can improve the overall buoyancy adjustment range and internal space utilization. When adjusted synchronously, the overall buoyancy can be changed more evenly. When adjusted independently, the buoyancy distribution in the front-to-back or left-to-right areas can be improved, reducing the risk of roll and pitch deviation and improving the stability of the robot in different cleaning postures.

[0024] In some example embodiments of this disclosure, based on the foregoing scheme, the buoyancy control device further includes: a controller, which is connected to the drive component and is used to control the degree to which the drive component compresses or releases the closed-cell foam buoyancy component according to the buoyancy control command; wherein the buoyancy control command can be used to characterize at least one control intention of the pool cleaning robot to perform floating, sinking or maintaining the current buoyancy state.

[0025] By configuring a controller that adjusts the compression or release of the closed-cell foam buoyancy component based on buoyancy control commands, buoyancy adjustment is no longer a fixed action. Instead, it can respond to different control requirements, such as user commands, working mode switching commands, surfacing commands, sinking commands, constant depth suspension commands, or obstacle avoidance commands. In scenarios where the user needs the robot to return to the water surface, dive to the target area, switch to waterline cleaning, or perform buoyancy obstacle avoidance, the controller can adapt and control the volume change of the closed-cell foam buoyancy component according to the buoyancy control commands. This reduces action lag or overshoot caused by mismatch between buoyancy actions and actual control requirements, improving the flexibility and operational stability of the pool cleaning robot's buoyancy control in different operating scenarios such as pool bottom, side walls, waterline, and surface return.

[0026] According to a second aspect of the present disclosure, a pool cleaning robot is provided, comprising: a body; a cleaning component disposed on the body for cleaning a pool; a walking component disposed on the body for driving the pool cleaning robot to move within the pool; and a buoyancy control device as described in the first aspect, wherein the buoyancy control device is located in water when the pool cleaning robot is in a surface state and an underwater state; wherein the buoyancy control device is disposed on the body, the housing of the buoyancy control device is connected to water outside the body through the water-permeable structure, and the buoyancy control device is used to adjust the buoyancy of the pool cleaning robot, causing the pool cleaning robot to perform an upward movement, a downward movement, or a constant-depth suspension movement.

[0027] By integrating the body, cleaning components, walking components, and buoyancy control device into the pool cleaning robot, and ensuring that the buoyancy control device is located in the water in both surface and underwater states and is connected to the external water body through a water-permeable structure, the robot can directly adjust the buoyancy of the whole machine by utilizing the volume change of the closed-cell foam buoyancy component during the cleaning process. This allows it to float, sink, or suspend at a constant depth, reducing reliance on external auxiliary buoyancy structures, independent airbags, or complex water injection and drainage chambers. This improves the adaptability and structural integration of the pool cleaning robot for multi-area cleaning.

[0028] According to a third aspect of the present disclosure, a method for controlling the buoyancy of a swimming pool cleaning robot is provided. The swimming pool cleaning robot includes a buoyancy control device, which includes a closed-cell foam buoyancy component, a drive assembly, and a shell communicating with external water. The closed-cell foam buoyancy component is disposed within the shell. The method includes: when the swimming pool cleaning robot is in an aquatic environment, acquiring a buoyancy control command; and controlling the drive assembly to compress or release the closed-cell foam buoyancy component according to the buoyancy control command. Specifically, when the buoyancy control command instructs the swimming pool cleaning robot to sink, the drive assembly is controlled to compress the closed-cell foam buoyancy component, reducing its volume and allowing external water to enter the shell, thereby reducing the buoyancy of the swimming pool cleaning robot; when the buoyancy control command instructs the swimming pool cleaning robot to float, the drive assembly is controlled to release the closed-cell foam buoyancy component, restoring its original shape and increasing its volume, and discharging water from the shell, thereby increasing the buoyancy of the swimming pool cleaning robot.

[0029] By acquiring buoyancy control commands when the robot is in an aquatic environment, and controlling the drive components to compress or release closed-cell foam buoyancy components according to these commands, the buoyancy of the pool cleaning robot can be selectively reduced or increased based on different control requirements such as user operation, work mode switching, surfacing and returning, sinking for cleaning, fixed-depth suspension, or snorkeling and obstacle avoidance. Thus, when the buoyancy control command indicates sinking, the buoyancy can be reduced by compressing the closed-cell foam buoyancy components, allowing the robot to move to a deeper position; when the buoyancy control command indicates surfacing, the buoyancy can be increased by releasing the closed-cell foam buoyancy components, allowing the robot to move to the surface or a shallower position. This improves the matching degree between buoyancy control actions and actual operational needs, reduces action lag or overshoot caused by fixed buoyancy adjustment strategies, and enhances the initiative and adaptability of the pool cleaning robot in buoyancy control in different scenarios such as pool bottom cleaning, waterline cleaning, surface return, and obstacle avoidance.

[0030] In some exemplary embodiments of this disclosure, based on the foregoing scheme, the drive assembly includes a power component, a first piston, a second piston, and a sealed hydraulic chamber connecting the first piston and the second piston; controlling the drive assembly to compress the closed-cell foam buoyancy component includes: controlling the power component to drive external water into the side of the first piston away from the sealed hydraulic chamber to push the first piston to move and cause the first piston to adjust the hydraulic pressure in the sealed hydraulic chamber; using the hydraulic medium in the sealed hydraulic chamber to drive the second piston to move toward the closed-cell foam buoyancy component to compress the closed-cell foam buoyancy component; wherein, the cross-sectional area of ​​the first piston is smaller than the cross-sectional area of ​​the second piston, and the second piston compresses the closed-cell foam buoyancy component with an output thrust greater than the input thrust of the first piston.

[0031] By controlling the power component during the compression control process to drive external water into the side of the first piston away from the sealed hydraulic chamber, the first piston is pushed to move, and the hydraulic medium drives the second piston with a larger cross-sectional area to move towards the closed-cell foam buoyancy component. This allows a smaller input thrust to be converted into a larger output compression thrust, thereby reducing the power and size requirements of the power component, while ensuring that the closed-cell foam buoyancy component can be reliably compressed. This improves the robot's responsiveness and structural compactness when it needs to sink.

[0032] In some exemplary embodiments of this disclosure, based on the foregoing scheme, controlling the drive assembly to release the closed-cell foamed buoyancy component includes: controlling the power component to drive the water on the side of the first piston away from the sealed hydraulic chamber to be discharged, or controlling the reversing valve to switch the flow direction of the external water relative to the side of the first piston away from the sealed hydraulic chamber; wherein, after the water pressure on the side of the first piston away from the sealed hydraulic chamber decreases, the hydraulic pressure in the sealed hydraulic chamber decreases, and the closed-cell foamed buoyancy component pushes the second piston to reset by the elastic expansion force generated when it recovers itself.

[0033] By controlling the power component to drive the water on the side of the first piston away from the sealed hydraulic chamber during the release control process, or by controlling the reversing valve to switch the flow direction of the external water relative to the side of the first piston away from the sealed hydraulic chamber, the water pressure on the side of the first piston away from the sealed hydraulic chamber is reduced, and the hydraulic pressure in the sealed hydraulic chamber is reduced. The elastic expansion force generated when the closed-cell foam buoyancy component recovers itself is used to push the second piston to reset. Therefore, the release action can be completed without setting an additional active pull-back mechanism or air-filled reset structure, reducing structural complexity and improving the stability and long-term reliability of the robot's floating process.

[0034] In some example embodiments of this disclosure, based on the foregoing scheme, controlling the drive component to compress or release the closed-cell foamed buoyancy component according to the buoyancy control command includes: determining the running direction and running parameters of the drive component according to the buoyancy control command, wherein the running direction includes a compression direction or a release direction, and the running parameters include at least one of running time, running speed, output pressure, and compression displacement; and controlling the drive component to operate according to the running direction and the running parameters.

[0035] By determining the running direction of the drive component and at least one of the following operating parameters—running time, running speed, output pressure, and compression displacement—based on the buoyancy control command, the direction and intensity of the drive component's movement can be matched with control intentions such as buoyancy, sinking, maintaining the current buoyancy state, or switching operating modes. This reduces over-compression, over-release, and buoyancy overshoot, decreases ineffective movements of the drive component and fatigue wear of closed-cell foam buoyancy components, and improves the control accuracy and operational stability of the buoyancy control device in response to different buoyancy requirements.

[0036] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0037] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0038] Figure 1 The schematic diagram illustrates the composition of a buoyancy control device for a pool cleaning robot according to some embodiments of the present disclosure.

[0039] Figure 2 The illustration schematically shows a control drive assembly that compresses or releases a closed-cell foam buoyancy component according to some embodiments of the present disclosure.

[0040] Figure 3 The diagram illustrates a configuration of a hydraulic lever mechanism for compressing or releasing a closed-cell foam buoyancy member according to some embodiments of the present disclosure.

[0041] Figure 4 A schematic diagram illustrating the composition of a pool cleaning robot according to some embodiments of the present disclosure is shown.

[0042] Figure 5 The schematic diagram illustrates a flow chart of a buoyancy control method for a pool cleaning robot according to some embodiments of the present disclosure.

[0043] Figure 6 The illustration schematically shows a process diagram of controlling the compression or release of the closed-cell foamed buoyancy component by a drive assembly based on the current water depth and the target water depth according to some embodiments of the present disclosure.

[0044] In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts. Detailed Implementation

[0045] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this specification. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this specification as detailed in the appended claims.

[0046] Furthermore, the accompanying drawings are for illustrative purposes only and are not necessarily drawn to scale. The block diagrams shown in the drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0047] Currently, in related technologies, some pool cleaning robots primarily achieve buoyancy control by inflating and deflating airbags. This involves using an air pump to inflate the airbags to increase buoyancy or releasing gas to decrease buoyancy. While this method can alter the robot's buoyancy, it requires an air pump, valve body, air hoses, and flexible airbags, resulting in a complex structure. Furthermore, the air pump can generate noise during operation. Additionally, the flexible airbags, constantly exposed to the aquatic environment and undergoing repeated expansion and contraction, are prone to material aging, fatigue, damage, or leakage, leading to insufficient long-term reliability of buoyancy control.

[0048] In addition, some related technologies achieve buoyancy control through water injection and drainage. For example, an independent water tank is set up, and water is injected into or drained from the tank through pumps and pipelines to change the robot's buoyancy. This method requires the coordination of an independent water tank, pump, valve, and pipeline, and has high requirements for sealing and water flow unobstructedness, which occupies a large amount of internal space. Furthermore, pool water usually contains debris such as mud, hair, and leaf debris, which can easily enter the injection and drainage channels or pump and valve structures, causing blockages, wear, or maintenance difficulties, affecting the long-term stable operation of the buoyancy control device.

[0049] Furthermore, while the piston-driven buoyancy system can regulate the water flow through piston movement, the piston, cylinder, and seals often need to be in contact with the pool water, placing high demands on the machining precision and wear resistance of the dynamic sealing structure. During long-term operation, particulate matter in the pool water can easily enter the sealing surfaces, causing piston jamming, seal wear, or leakage, thus affecting the accuracy and reliability of buoyancy adjustment.

[0050] Based on one or more problems existing in related technologies, this example embodiment first provides a buoyancy control device for a pool cleaning robot. This device can be configured inside the robot's body, on its side, or near the buoyancy adjustment area. It is used to change the buoyancy experienced by the robot when it is in an aquatic environment. The buoyancy control device can be assembled as an independent module into the pool cleaning robot or integrated into its body structure. This buoyancy control device does not rely on filling or expelling gas into the robot's internal closed cavity as its primary buoyancy mechanism. Instead, it uses the volume substitution relationship between its internal variable volume structure and the external water to create a basis for buoyancy changes, enabling the pool cleaning robot to float or sink between different cleaning areas. Since this buoyancy control process mainly occurs in the aquatic environment and does not rely on external air supply, it is suitable for continuous cleaning scenarios in areas with different water depths, such as the bottom, side walls, and near the waterline of a pool.

[0051] Figure 1 A schematic diagram illustrating the composition of a buoyancy control device for a pool cleaning robot according to some embodiments of the present disclosure is shown. (Reference) Figure 1 As shown, the buoyancy control device 100 of the pool cleaning robot may include at least a housing 110, a closed-cell foam buoyancy component 120, and a drive assembly 130, wherein: The housing 110 serves as a supporting structure for the buoyancy control device 100, accommodating the closed-cell foam buoyancy component 120 and the drive assembly 130, and providing installation space for the compression, recovery, and water inflow / outflow of the closed-cell foam buoyancy component 120. The housing 110 can be made of plastic, composite materials, metal, or a combination thereof, and can be configured as a box-shaped, cylindrical, strip-shaped, or irregularly shaped structure adapted to the external shape of the pool cleaning robot, depending on its internal space. The housing 110 can be fixedly installed on the inner wall, bottom, side, or other locations within the pool cleaning robot that participate in buoyancy adjustment, or it can be connected to the robot body via snap-fit, screws, welding, bonding, or integral molding.

[0052] The shell 110 is provided with a water-passing structure 111, which is used to connect the interior of the shell 110 with the external water body. The water-passing structure 111 can be understood as a structure that allows pool water to flow between the inside and outside of the shell 110. It can be a hole, groove, grid, gap, opening, or a combination of the above structures, as long as it allows water to enter or exit the shell 110 when the volume of the closed-cell foamed buoyancy member 120 changes. The water-passing structure 111 can be located at the bottom, side, top, or in multiple directions of the shell 110 to avoid affecting the water inflow and outflow efficiency due to obstruction in one direction. The opening size and distribution density of the water-passing structure 111 can be set according to the water flow resistance, the risk of debris passage, and the strength requirements of the shell 110. By keeping the interior of the shell 110 connected to the external water body, the shell 110 does not need to form a completely sealed chamber for pressurized water storage. Water can naturally enter or exit as the available space inside the shell 110 changes, thereby reducing the space and assembly precision requirements of independent water tanks, complex pipelines, and high-precision sealing structures.

[0053] A closed-cell foamed buoyancy component 120 is disposed within the shell 110 and is used to change its volume within the shell 110 during its own deformation. The closed-cell foamed buoyancy component 120 can be understood as a foamed elastic buoyancy component with a closed-cell structure inside. The closed pores in this type of structure are isolated or substantially isolated from each other, making it difficult for external water to enter the interior of the closed-cell foamed buoyancy component 120, thus enabling the closed-cell foamed buoyancy component 120 to maintain its buoyancy contribution in water. The closed-cell foamed buoyancy component 120 can be made of closed-cell foamed silicone, closed-cell foamed rubber, closed-cell foamed polyurethane, or other elastic foamed materials with compressible, resilient, and non-absorbent properties. The closed-cell foam buoyancy component 120 can be shaped into a block, column, sheet, ring, or irregular shape that matches the internal cavity of the shell 110, depending on the internal space of the shell 110. Its surface can directly contact the portion of the drive assembly 130 located inside the shell 110, or indirectly contact the drive assembly 130 through a pressure plate, gasket, or force transmission component. When uncompressed, the closed-cell foam buoyancy component 120 occupies a large portion of the internal space of the shell 110 and contributes buoyancy to the pool cleaning robot. After being compressed by external force, its volume decreases, and the space released inside the shell 110 can be replenished by external water. Since the closed-cell foam buoyancy component 120 does not need to be inflated and deflated like a flexible airbag, nor does it need to form a thin-film airtight structure, it can reduce the impact of repeated air pressure changes and long-term immersion on the lifespan of the buoyancy structure, which helps to reduce the risk of buoyancy control failure caused by aging, fatigue, or rupture of the flexible airbag.

[0054] The drive assembly 130 is at least partially disposed within the housing 110, and is used to apply compression to or release compression of the closed-cell foam buoyancy member 120. "At least partially disposed within the housing 110" can be understood as the drive assembly 130 being entirely disposed within the housing 110, or only the portion of the drive assembly 130 that directly or indirectly transmits force to the closed-cell foam buoyancy member 120 being disposed within the housing 110, while the power source, transmission source, control connection, or hydraulic supply portion of the drive assembly 130 is disposed outside the housing 110. This arrangement allows the drive assembly 130 to not completely occupy the internal space of the housing 110, enabling flexible arrangement based on the actual spatial distribution within the pool cleaning robot.

[0055] In some embodiments, the portion of the drive assembly 130 located within the housing 110 may include a pressure plate, pressure head, push rod end, piston end, slider, or other compression actuator. This compression actuator is disposed opposite to the closed-cell foam buoyancy member 120 and is capable of moving toward the closed-cell foam buoyancy member 120 when the drive assembly 130 is activated, thereby compressing the closed-cell foam buoyancy member 120. In other embodiments, the portion of the drive assembly 130 located outside the housing 110 may include a motor, reduction mechanism, lead screw drive mechanism, gear transmission mechanism, pump body, valve body, hydraulic supply structure, or combinations thereof. This portion may be mounted on the outside of the housing 110, on the internal support of the pool cleaning robot, or in a functional installation area adjacent to the housing 110. The portion located outside the housing 110 may be connected to the compression actuator located within the housing 110 via a transmission rod, push rod, connecting rod, flexible force transmission element, hydraulic line, or other transmission connection structure, thereby transmitting driving force to the closed-cell foam buoyancy member 120.

[0056] In some embodiments, the drive assembly 130 may pass through the wall of the housing 110 or extend into the housing 110 through a mounting hole. Since the housing 110 itself is connected to the external water body through the water passage structure 111, it does not require the formation of a completely sealed pressure chamber. Therefore, when the drive assembly 130 passes through or partially extends into the housing 110, the focus can be on ensuring transmission stability and installation strength, without relying on high-precision dynamic seals to isolate the pool water as is required in sealed water tanks or piston pumping structures. If necessary, guide sleeves, limiting members, sealing rings, protective covers, or debris-proof structures can still be provided between the drive assembly 130 and the housing 110 to reduce the entry of mud, hair, or leaf debris into the transmission gap and improve the stability of the drive assembly 130 during operation.

[0057] In some embodiments, placing the drive assembly 130 at least partially within the housing 110 allows the portion of the drive assembly 130 performing the compression action to be directly close to the closed-cell foam buoyancy member 120, shortening the compression force transmission path and reducing transmission clearance and off-center load risk. Simultaneously, placing the power source or larger components of the drive assembly 130 outside the housing 110 reduces the internal space occupied by the housing 110, allowing more space within the housing 110 for the deformation of the closed-cell foam buoyancy member 120 and water entry / exit. For small pool cleaning robots, this arrangement improves the spatial adaptability between the buoyancy control device 100 and other internal components, and facilitates the assembly, heat dissipation, maintenance, and replacement of the drive assembly 130.

[0058] When the drive assembly 130 compresses the closed-cell foam buoyancy component 120, the compression actuator of the drive assembly 130 located within the housing 110 applies a compression action to the closed-cell foam buoyancy component 120, causing the closed pores inside the closed-cell foam buoyancy component 120 to be squeezed, reducing the overall volume of the closed-cell foam buoyancy component 120, and correspondingly reducing the space it occupies inside the housing 110. Since the housing 110 is connected to the external water body through the water passage structure 111, the external water body can enter the housing 110 through the water passage structure 111 under the action of water pressure and space compensation to fill the space formed by the reduced volume of the closed-cell foam buoyancy component 120. At this time, the space inside the pool cleaning robot that was originally occupied by the closed-cell foam buoyancy component 120 and used to provide buoyancy is replaced by water, and the buoyancy of the robot as a whole decreases, thereby enabling the pool cleaning robot to sink. This process does not require actively drawing water into the pool through a closed piston cylinder, nor does it require completing the water injection action through an independent sealed water tank. Therefore, it can reduce buoyancy with a relatively simplified water body connection structure and reduce the structural complexity caused by pumping and draining sealing structures, injection and draining pipelines, or independent tanks.

[0059] When the drive assembly 130 releases the closed-cell foam buoyancy component 120, the compression actuator of the drive assembly 130 located within the housing 110 moves away from the closed-cell foam buoyancy component 120, or reduces the holding pressure on the closed-cell foam buoyancy component 120, allowing the closed-cell foam buoyancy component 120 to gradually recover to its larger volume state based on its own elastic recovery ability. As the volume of the closed-cell foam buoyancy component 120 increases, it occupies more space inside the housing 110 and squeezes some of the water that previously entered the housing 110 into the external water body through the water passage structure 111. At this time, the space occupied by water inside the housing 110 decreases, the contribution of the closed-cell foam buoyancy component 120 to the overall buoyancy of the pool cleaning robot increases, and the buoyancy experienced by the robot increases accordingly, thereby enabling the pool cleaning robot to have an upward tendency. Since the buoyancy process can be completed by the recovery process of the closed-cell foamed buoyancy component 120 and the water discharge process inside the shell 110, the dependence on gas supply, air circuit sealing and airbag inflation and deflation processes can be reduced, and the impact of gas flow noise and fatigue damage of flexible airbags on the reliability of buoyancy control can be reduced.

[0060] The compressed and released states of the closed-cell foam buoyancy component 120 correspond to different buoyancy states of the pool cleaning robot. The drive assembly 130, by changing the pressure on the closed-cell foam buoyancy component 120, can alter the volume of external water entering or exiting the shell 110, thereby creating different degrees of buoyancy adjustment. For the pool cleaning robot, this buoyancy adjustment method links the floating and sinking motions to the volume changes of the closed-cell foam buoyancy component 120, providing a more direct mechanical correspondence between the rising and sinking processes, and reducing the impact of multi-stage conversion processes such as gas inflation / deflation and independent chamber water injection / discharge on response stability. Through this floating and sinking control method, the pool cleaning robot can be equipped with a relatively compact floating and sinking control device 100 within a limited body space, and achieve buoyancy changes in the aquatic environment, providing stable floating and sinking motions for cleaning operations in multiple areas such as the pool bottom, side walls, and near the waterline.

[0061] According to the buoyancy control method of the pool cleaning robot in this example embodiment, on the one hand, by using a compressible and recoverable closed-cell foam buoyancy component as the direct object of buoyancy change, the buoyancy adjustment of the pool cleaning robot no longer depends on the gas inflation / deflation process. The buoyancy change can be based on the volume change of the buoyancy component itself, thereby reducing the working noise introduced by the gas inflation / deflation process and reducing the risk of aging, fatigue, or damage to the flexible airbag after long-term immersion and repeated deformation, thus improving the structural reliability of the pool cleaning robot when performing buoyancy and sinking actions for a long time. On the other hand, by connecting the inside of the shell with the external water body and allowing water to enter or exit the shell with the volume change of the buoyancy component, the buoyancy adjustment process does not need to rely on the gas inflation / deflation process. The piston cylinder performs high-precision sealing and pumping of pool water, eliminating the need for complex injection and drainage pipelines around independent water tanks. This reduces the reliance of the buoyancy control device on dynamic sealing structures and sealed chambers, minimizing the possibility of jamming, wear, or seal failure caused by debris such as mud, hair, or leaf fragments in the pool water. Furthermore, by transforming the buoyancy adjustment process into a coordinated process of buoyancy component volume change and water inflow / outflow within the shell, the structure required for buoyancy control can complete buoyancy changes with fewer chambers and pipelines. This reduces the structural complexity and space occupation of the device, improves its adaptability within the body of a small pool cleaning robot, and enhances the stability of the pool cleaning robot's buoyancy movements during cleaning operations in multiple areas such as the bottom, side walls, and waterline.

[0062] Below, in conjunction with Figures 1 to 3 The buoyancy control device of the pool cleaning robot will be further explained.

[0063] In one example embodiment of this disclosure, reference continues to be made to... Figure 1 As shown, the closed-cell foam buoyancy component 120 has multiple non-interconnected closed-cell bubbles 121 inside; under the compression action of the drive component 130, the volume of each closed-cell bubble 121 is compressed, and the closed-cell foam buoyancy component 120 deforms from a first volume to a second volume, and the second volume is smaller than the first volume; and after being released by the drive component 130, the closed-cell foam buoyancy component 120 recovers from the second volume to the first volume by relying on the elastic expansion force generated by the closed-cell bubbles 121 during recovery.

[0064] The closed-cell foamed buoyancy component contains multiple non-interconnected closed-cell air bubbles. These closed-cell air bubbles can be understood as closed cavities formed by the foamed material matrix, isolated from each other by the material matrix, and without forming a through water channel between them and the external water body. These multiple closed-cell air bubbles can be randomly distributed within the closed-cell foamed buoyancy component, or they can form a relatively uniform pore distribution along the compression direction, thickness direction, or length direction. The size, number, and distribution density of the closed-cell air bubbles can be set according to the required buoyancy, compression deformation capacity, and recovery capacity of the closed-cell foamed buoyancy component. In actual manufacturing, multiple closed-cell air bubbles can be integrally formed within the elastic material matrix through a foaming molding process, or a single buoyancy component can be formed by stacking, molding, or cutting multiple layers of closed-cell foamed material. Because the closed-cell air bubbles are not interconnected, external water cannot easily form continuous seepage channels between the closed-cell air bubbles to enter the interior of the closed-cell foamed buoyancy component. This allows the closed-cell foamed buoyancy component to maintain a relatively stable internal gas space even under long-term immersion conditions, thus providing a structural basis for subsequent volume compression and elastic recovery.

[0065] Multiple closed-cell bubbles are not limited to perfectly identical spherical cavities; they can be approximately spherical, ellipsoidal, polyhedral, or irregularly shaped closed cavities formed by foaming. This embodiment does not impose any special limitations on this. For closed-cell bubbles of different shapes, as long as they can undergo recoverable volume reduction under external force and exhibit a tendency to recover after the external force is removed, they can be used to form the compressibility and recoverability of closed-cell foamed buoyancy components. To improve the stability of closed-cell foamed buoyancy components during repeated compression, the material matrix surrounding the closed-cell bubbles can have a certain elastic modulus and fatigue resistance, enabling the closed-cell bubbles to undergo reversible deformation under compression rather than significant rupture or permanent collapse. Through this structure combining internal closed cavities with an elastic material matrix, the closed-cell foamed buoyancy component can undergo overall deformation when subjected to compression applied by the drive component and exhibit a tendency to recover its original shape after the drive component is released.

[0066] Under the compression action of the driving component, the volume of each closed-cell foam buoyancy component is compressed, causing the closed-cell foam buoyancy component to deform from a first volume to a second volume. The first volume can be understood as the outer envelope volume of the closed-cell foam buoyancy component when it is not compressed by the driving component or is in a released state, while the second volume can be understood as the outer envelope volume formed after the closed-cell foam buoyancy component is compressed by the driving component. During the deformation of the closed-cell foam buoyancy component from the first volume to the second volume, the external force applied by the driving component is transmitted through the outer surface of the closed-cell foam buoyancy component to the internal material matrix and closed-cell bubbles, causing each closed-cell bubble to shrink, flatten, or change shape along the direction of pressure or local force. Since the gas inside the closed-cell bubbles is difficult to escape, the compression of the closed-cell bubbles will result in a combined effect of internal gas compression and elastic deformation of the material matrix, thereby reducing the overall volume of the closed-cell foam buoyancy component.

[0067] The second volume being smaller than the first volume indicates that the closed-cell foam buoyancy component occupies less internal space in the shell under compressed conditions than it does under released conditions. The first and second volumes can be characterized by changes in the closed-cell foam buoyancy component's external dimensions, envelope space, or drainage volume. Specifically, the first volume corresponds to the volume state of the closed-cell foam buoyancy component after natural unfolding or near-restoration, while the second volume corresponds to the compressed volume state of the closed-cell foam buoyancy component after pressure is applied by the drive component. When the closed-cell foam buoyancy component changes between the first and second volumes, its internal closed-cell air bubbles do not form numerous water infiltration paths like open-cell materials; therefore, the volume change is mainly caused by the elastic deformation of the closed-cell air bubbles and the material matrix. Thus, under the same external water environment, the closed-cell foam buoyancy component can participate in buoyancy regulation through repeatable volume changes, reducing the problem of uncontrollable buoyancy changes caused by water absorption or pore connectivity.

[0068] After being released by the driven component, the closed-cell foam buoyancy component recovers from its second volume to its first volume due to the elastic expansion force generated by the closed-cell bubbles during recovery. This elastic expansion force can originate from the recovery tendency of the gas inside the closed-cell bubbles after compression, or from the rebound force generated by the elastic material matrix surrounding the closed-cell bubbles after deformation under pressure. When the driving component releases or reduces the compression of the closed-cell foam buoyancy component, the compressed gas inside the closed-cell bubbles tends to recover its original volume, and the material matrix also tends to recover its shape before compression. Both factors together cause the closed-cell foam buoyancy component to recover from its second volume to its first volume. Because this recovery process relies on the elastic properties of the closed-cell foam buoyancy component itself, it can recover its volume without relying on external gas replenishment, and it does not generate excessive noise. It also has lower requirements for structural precision, making it suitable for repeated compression and release in aquatic environments.

[0069] Understandably, the recovery of a closed-cell foam buoyancy component from its second volume to its first volume does not require instantaneous completion, nor does it require that the microscopic cavity morphology be completely consistent after each recovery. As long as the closed-cell foam buoyancy component can recover to the volume state that meets the buoyancy adjustment requirements after the drive component is released, it can be considered that it has recovered from the second volume to the first volume. To reduce the impact of repeated compression on the stability of the closed-cell bubble structure, materials with non-absorbency, good elastic recovery performance, and low permanent compression deformation (i.e., good self-recovery characteristics) can be selected for the closed-cell foam buoyancy component, such as closed-cell polyurethane foam and closed-cell foam rubber. Alternatively, by controlling the size distribution of the closed-cell bubbles, the material hardness, and the thickness of the buoyancy component, the closed-cell foam buoyancy component can maintain usable recovery ability after multiple compression cycles. Through this structural characteristic of closed-cell bubble compression and elastic recovery, the closed-cell foam buoyancy component can provide a more stable source of volume change during the buoyancy control of the pool cleaning robot, reducing the risk of buoyancy adjustment failure caused by local rupture, air leakage, or fatigue deformation of traditional membrane airbags.

[0070] By setting up a closed-cell foam buoyancy component, multiple non-interconnected closed-cell air bubbles are formed inside. When the component is under pressure, the overall volume is reduced mainly by the volume compression of each closed-cell air bubble. After release, the volume is restored by the elastic recovery of the closed-cell air bubbles and the material matrix. This allows for the formation of a repeatable buoyancy change basis without introducing a gas inflation / deflation structure. This reduces reliability issues caused by aging and damage of flexible airbags, air leakage failures, and inflation / deflation noise, and improves the stability of the float-sink control device during long-term cyclic operation.

[0071] In one example embodiment of this disclosure, the compression ratio of the closed-cell foamed buoyancy component when deformed from the first volume to the second volume can be 30% to 50%; the volume of water entering or exiting the interior of the shell is related to the volume difference between the first volume and the second volume.

[0072] Compression ratio can be understood as the reduction in volume of a closed-cell foam buoyancy component after compression by the driven component, relative to its initial volume. It can be characterized by the ratio of the difference between a first volume and a second volume to the first volume. For example, compression ratio can be expressed as the ratio of the difference between the first volume and the second volume to the first volume. The first volume corresponds to the overall volume of the closed-cell foam buoyancy component in its released or naturally recovering state, while the second volume corresponds to its overall volume under pressure. Because the closed-cell foam buoyancy component contains multiple closed-cell air bubbles, its volume reduction during compression is not achieved by discharging absorbed water, but rather through the elastic deformation of the closed-cell air bubbles and the surrounding material matrix. Therefore, compression ratio reflects the effective volume adjustment capability of the closed-cell foam buoyancy component during buoyancy control.

[0073] This embodiment sets the compression ratio of the closed-cell foam buoyancy component to 30% to 50%, allowing the buoyancy control device to achieve a good balance between buoyancy adjustment and material recovery stability. If the compression ratio is too small, the volume difference formed when the closed-cell foam buoyancy component deforms from the first volume to the second volume is small, limiting the volume change that can be filled or discharged by external water inside the shell. This may result in insufficient buoyancy adjustment, making it difficult to meet the needs of the pool cleaning robot to sink from the surface area to deeper water or switch between different cleaning areas. If the compression ratio is too large, the closed-cell air bubbles and the material matrix inside the closed-cell foam buoyancy component will be subjected to a high degree of deformation, which may increase the risk of closed-cell air bubble breakage, permanent material compression deformation, or decreased recovery speed, thereby affecting the reusability of the closed-cell foam buoyancy component in multiple buoyancy cycles. Therefore, a compression ratio range of 30% to 50% can provide a significant volume change while reducing the adverse effects of excessive compression on the elastic recovery performance of the closed-cell foam buoyancy component.

[0074] The compressibility of closed-cell foam buoyancy components can be designed by matching factors such as material hardness, closed-cell bubble density, closed-cell bubble size distribution, buoyancy component thickness, pressure-bearing area, and the stroke of the drive assembly. For closed-cell foam buoyancy components with high elasticity and uniform closed-cell bubble distribution, a more stable volume change can be obtained with a smaller drive stroke. For closed-cell foam buoyancy components with high hardness or large thickness, the pressure-bearing area can be appropriately increased or the shape of the buoyancy component can be optimized to ensure uniform deformation within the specified compressibility range.

[0075] Optionally, the closed-cell foam buoyancy component can be a monolithic molded component or a buoyancy component formed by stacking multiple layers of closed-cell foam materials; in the multi-layer structure, each layer of material can have the same or different elastic recovery properties, so that the closed-cell foam buoyancy component forms a progressive compression process when under pressure.

[0076] Understandably, since the shell is connected to the external water body through the water-permeable structure, when the closed-cell foam buoyancy component is compressed from the first volume to the second volume, the space occupied by the closed-cell foam buoyancy component within the shell decreases. This creates space within the shell that can be replenished by external water, allowing it to enter the shell through the water-permeable structure. Conversely, when the closed-cell foam buoyancy component returns to its original volume from the second volume to the first volume, it re-occupies a larger portion of the internal space of the shell, pushing some of the water within the shell out through the water-permeable structure. Therefore, the greater the volume difference between the first and second volumes, the larger the volume of water that can enter or exit the shell, and the greater the range of buoyancy variation that the pool cleaning robot can achieve. Conversely, the smaller the volume difference between the first and second volumes, the smaller the water exchange within the shell, and the smaller the range of buoyancy variation.

[0077] The volume of water entering or exiting the shell can generally correspond to the volume difference between the first and second volumes, but it can also deviate due to factors such as gaps in the internal structure of the shell, flow resistance of the water passage structure, surface deformation of the closed-cell foam buoyancy component, and water flow lag. In practical design, the volume difference between the first and second volumes can be preset based on the target buoyancy of the pool cleaning robot, the internal space of the shell, and the compression stroke of the closed-cell foam buoyancy component. By adjusting the flow area of ​​the water passage structure, the installation gap of the closed-cell foam buoyancy component, and the water flow path inside the shell, water can enter or exit the shell in a timely manner. In this way, the volume change of the closed-cell foam buoyancy component can be stably translated into a change in the space occupied by the water inside the shell, reducing buoyancy adjustment lag caused by insufficient water exchange.

[0078] By setting the compression rate of the closed-cell foam buoyancy component from the first volume to the second volume to 30% to 50%, the closed-cell foam buoyancy component can generate sufficient volume change to drive water into or out of the shell, while avoiding excessive compression that could lead to the collapse of closed-cell bubbles, permanent deformation of the material, or a decrease in its recovery ability. This achieves a balance between the buoyancy adjustment range and the lifespan of the closed-cell foam buoyancy component, thereby improving the controllability and repeatability of the sinking and floating actions of the pool cleaning robot.

[0079] In one example embodiment of this disclosure, reference is made to Figure 1 and Figure 2 As shown, the drive assembly 130 may include a power component 131 and a compression component 132. The power component 131 and the compression component 132 are connected in a transmission manner, and the compression component 132 is disposed opposite to the closed-cell foam buoyancy component 120. When the power component 131 drives the compression component 132 to move toward the closed-cell foam buoyancy component 120, the drive assembly 130 compresses the closed-cell foam buoyancy component 120, and when the compression component 132 moves away from the closed-cell foam buoyancy component 120, the drive assembly 130 releases the closed-cell foam buoyancy component 120.

[0080] The power component provides driving force or displacement output for the compression and release process of the closed-cell foam buoyancy component, while the compression component applies the driving force or displacement output by the power component to the closed-cell foam buoyancy component. The power component can be understood as a part capable of generating mechanical motion or driving energy, and its selection depends on the internal space of the pool cleaning robot, the power supply method, and the required compression force. For example, the power component can use a drive structure formed by a motor and transmission mechanism, or it can use a linear actuator, push rod mechanism, pump-type power source, or other power structure capable of outputting controllable displacement. The power component can be fixed to a mounting base, reinforcing rib, or support frame within the housing to ensure its positional stability relative to the housing during operation. To adapt to the aquatic environment of the pool cleaning robot, the power component can employ waterproof encapsulation, potting, sealing covers, or water-proof installation structures to reduce the risk of water entering the power component and affecting the stability of the power output.

[0081] The compression component and the power component are connected by a transmission mechanism. This transmission connection can be understood as the motion or force output by the power component being transmitted to the compression component, causing it to displace towards or away from the closed-cell foam buoyancy component. The transmission connection can be direct or indirect. In a direct connection, the compression component can be directly fixed to the output end of the power component, such as to the end of a push rod or a sliding output end. In an indirect connection, the power component can drive the compression component to move via gears, connecting rods, cams, lead screws, slide rails, rocker arms, or flexible force transmission components. The specific form of the transmission connection can be set according to the driving direction, the internal installation space of the housing, and the force-bearing position of the closed-cell foam buoyancy component; this embodiment is not limited to these limitations. To reduce the deflection of the compression component during movement, guide grooves, guide rods, sliders, or limiting parts can also be provided in the transmission path to ensure smooth movement of the compression component in a predetermined direction.

[0082] The compression component and the closed-cell foam buoyancy component can be arranged opposite each other. This opposite arrangement means the compression component is positioned on one side of the closed-cell foam buoyancy component, with its working surface facing the component, so that it can apply compression to the component when moving. The compression component can be a pressure plate, push block, slider, push rod end face, arc-shaped pressure plate, or a force-bearing component that matches the shape of the closed-cell foam buoyancy component. For block-shaped closed-cell foam buoyancy components, the compression component can be a flat plate structure to provide a more uniform pressure area. For columnar, arc-shaped, or irregularly shaped closed-cell foam buoyancy components, the working surface of the compression component can be a corresponding arc surface, concave surface, or multi-segment surface to improve the fit and force distribution. The compression component and the closed-cell foam buoyancy component can initially contact each other, or a certain gap can be left so that the compression component contacts the component after moving a preset distance. By positioning the compression component relative to the closed-cell foam buoyancy component, the drive assembly can concentrate the compressive force onto the effective compression area of ​​the closed-cell foam buoyancy component, reducing local collapse, wear, or uneven deformation caused by force offset.

[0083] When the power component drives the compression component to move towards the closed-cell foam buoyancy component, the drive assembly compresses the closed-cell foam buoyancy component. Specifically, after the power component outputs driving force, the compression component moves towards the closed-cell foam buoyancy component under the action of the transmission connection. The working surface of the compression component contacts the closed-cell foam buoyancy component and gradually applies a clamping force, causing the closed-cell foam buoyancy component to undergo elastic deformation. This compression process can be a continuous compression process or a segmented compression process. In the continuous compression process, the compression component continuously approaches the closed-cell foam buoyancy component under the drive of the power component, causing the volume of the closed-cell foam buoyancy component to gradually decrease. In the segmented compression process, the compression component can move step by step according to a preset stroke, allowing the closed-cell foam buoyancy component to switch between multiple compression positions. The maximum movement position of the compression component can be constrained by mechanical limits, stroke limits, or drive control to avoid the closed-cell foam buoyancy component being over-compressed and affecting its subsequent recovery performance.

[0084] As the compressed component moves away from the closed-cell foam buoyancy component, the drive assembly releases the closed-cell foam buoyancy component. This release does not require the compressed component to actively pull the closed-cell foam buoyancy component; rather, it refers to the compressed component reducing or releasing the compressive constraint on the closed-cell foam buoyancy component, allowing it to recover its volume based on its own restorative properties. The movement of the compressed component away from the closed-cell foam buoyancy component can be achieved by the power component reversing and driving the compressed component back, or by the power component releasing the holding force and allowing the compressed component to return to the release position under external restoring action. The retraction stroke of the compressed component can correspond to its compression stroke or be set according to the recovery speed and recovery space of the closed-cell foam buoyancy component. To prevent the compressed component from suddenly detaching during release, causing the closed-cell foam buoyancy component to rebound rapidly or impact the shell, the retraction speed of the compressed component can be controlled by the output speed of the power component, transmission damping, or mechanical limits.

[0085] Understandably, the relative relationships between the power unit, the compression unit, and the closed-cell foam buoyancy component can be adaptively adjusted according to the layout space of the pool cleaning robot. For example, the power unit and the compression unit can be arranged horizontally, allowing the compression unit to compress the closed-cell foam buoyancy component from the side; or they can be arranged vertically or obliquely, allowing the compression unit to compress the closed-cell foam buoyancy component from above, below, or obliquely. The movement direction of the compression unit can be consistent with the main thickness direction of the closed-cell foam buoyancy component to achieve a larger volume change; alternatively, it can adopt an offset, swing, or oblique pushing motion path depending on the internal space of the shell to avoid other structures inside the pool cleaning robot. Regardless of the arrangement, as long as the power unit can switch the closed-cell foam buoyancy component between a compressed state and a released state through the compression unit, the compression and release functions can be achieved.

[0086] By setting the drive assembly to a structure that combines a power component and a compression component, and by positioning the compression component relative to the closed-cell foam buoyancy component, the output of the power component can be converted into a direct compression or release action on the closed-cell foam buoyancy component via the compression component. This simplifies the drive force transmission path, reduces the gaps, jamming, and response lag caused by the intermediate transmission structure, and improves the directness and consistency of the volume adjustment of the closed-cell foam buoyancy component.

[0087] In one example embodiment of this disclosure, reference is made to Figures 1 to 3As shown, the drive assembly 130 may further include a hydraulic lever mechanism 133. The hydraulic lever mechanism 133 may include a first piston 1331, a second piston 1332, and a sealed hydraulic chamber 1333. The sealed hydraulic chamber 1333 is used to connect the first piston 1331 and the second piston 1332. The sealed hydraulic chamber 1333 is isolated from the internal water-passing area of ​​the housing 110. The hydraulic medium in the sealed hydraulic chamber 1333 does not come into contact with external water entering the housing 110 through the water-passing structure 111. The cross-sectional area of ​​the first piston 1331 is smaller than that of the second piston 1332. The power component 131 is used to drive external water into or out of the side of the first piston 1331 away from the sealed hydraulic chamber 1333, so as to adjust the hydraulic pressure in the sealed hydraulic chamber 1333 through the first piston 1331. The second piston 1332 constitutes a compression component. Figure 3 The illustration shows a situation where the second piston 1332 constitutes the compressor, or the second piston 1332 is connected to the compressor in a transmission connection.

[0088] The hydraulic lever mechanism can be understood as a mechanism that uses hydraulic medium to transmit pressure within a closed space and changes the output force and displacement through the cooperation between different pressure-bearing areas. This hydraulic lever mechanism is positioned between the power component and the closed-cell foam buoyancy component, converting the pressure or displacement generated by the first piston under the action of external water into a compression action suitable for compressing the closed-cell foam buoyancy component. Compared to simply relying on a rigid mechanical push rod to directly push the closed-cell foam buoyancy component, the hydraulic lever mechanism can achieve more stable pressure transmission through the hydraulic medium and can flexibly arrange the positions of the first and second pistons within the limited space inside the shell. This eliminates the need for the power component and the closed-cell foam buoyancy component to be strictly coaxially aligned, thereby improving the adaptability of the buoyancy control device within the pool cleaning robot and reducing the design difficulty of the pool cleaning robot.

[0089] The first piston can serve as the input-side moving component of the hydraulic lever mechanism. It is used to apply water pressure from external water to the side of the first piston away from the sealed hydraulic chamber, transmitting this pressure to the hydraulic medium within the sealed chamber. The first piston can be a circular, elliptical, rectangular, or other piston structure capable of slidingly engaging with the corresponding chamber wall. Its outer periphery can be fitted with a sealing ring, flexible sealing lip, or elastic sealing sleeve to reduce mutual leakage of the medium on both sides of the first piston during its movement. The first piston can move linearly, or the non-linear motion output by the power component can be converted into reciprocating motion of the first piston through water pressure, a swinging component, an eccentric component, or a guide component. The stroke of the first piston can be set according to the output capacity of the power component, the volume change requirements of the sealed hydraulic chamber, and the required displacement of the second piston.

[0090] The second piston can serve as the output-side moving component of the hydraulic lever mechanism, used to output compression towards the closed-cell foam buoyancy component under the action of hydraulic medium within the sealed hydraulic chamber. The second piston can be equipped with a sealing structure similar to the first piston to ensure that the hydraulic medium within the sealed hydraulic chamber does not leak into the internal water-permeable area of ​​the housing during its reciprocating motion. The shape of the second piston can be circular, rectangular, elongated, or other suitable shapes depending on the internal space of the housing and the pressure-bearing area of ​​the closed-cell foam buoyancy component. The second piston can move in a straight line towards the closed-cell foam buoyancy component, or it can move stably in a preset direction under the constraint of a guide structure to reduce skewed forces. Since the second piston is located on the output side of the hydraulic lever mechanism, its smoothness of movement and output direction directly affect the compression uniformity of the closed-cell foam buoyancy component. Therefore, a guide sleeve, guide groove, or limiting structure can be provided on the outside of the second piston to maintain good directional consistency when compressing the closed-cell foam buoyancy component.

[0091] The sealed hydraulic chamber connects the first piston and the second piston. This connection is not limited to a rigid mechanical connection, but rather refers to the establishment of a pressure transmission relationship between the first and second pistons through an internal hydraulic medium. When the power component drives external water to act on the side of the first piston away from the sealed hydraulic chamber, causing the first piston to move, the first piston acts on the hydraulic medium within the sealed hydraulic chamber. The hydraulic medium transmits pressure to the second piston, causing it to move accordingly. The sealed hydraulic chamber can be a single continuous cavity or a multi-segment cavity connected by internal oil passages, hoses, connecting channels, or transition chambers, as long as a closed hydraulic force transmission path can be formed between the first and second pistons. This embodiment does not impose any special limitations on this. The hydraulic medium within the sealed hydraulic chamber can be hydraulic oil, silicone oil, or other essentially incompressible liquids suitable for transmitting pressure in a sealed environment. Transmitting pressure through the sealed hydraulic chamber reduces the number of mechanical transmission components and the limitations of transmission path bends, allowing for more flexible placement of the power component and enabling the second piston to obtain a more stable output pressure.

[0092] The sealed hydraulic chamber is isolated from the internal water-permeable area of ​​the shell. The internal water-permeable area of ​​the shell can be understood as the area that external water can reach after entering the shell through the water-permeable structure. The sealed hydraulic chamber is used to contain the hydraulic medium and transmit hydraulic pressure. The isolation between the two can be achieved through independent chamber walls, sealing sleeves, sealing covers, sealing rings, flexible diaphragms, or integrally formed isolation walls. By isolating the sealed hydraulic chamber from the internal water-permeable area, pool water entering the shell will not directly enter the sealed hydraulic chamber. Mud, hair, leaf debris, or disinfectant components in the pool water are also less likely to mix with the hydraulic medium. This reduces the risk of debris entering the hydraulic transmission path and causing obstruction of the first or second piston movement. It also reduces the impact of pool water on the performance of the hydraulic medium and the lifespan of the sealing structure, thereby improving the reliability of the hydraulic lever mechanism in long-term aquatic environments.

[0093] The hydraulic medium within the sealed hydraulic chamber does not come into contact with external water entering the shell via the water-permeable structure. This design ensures the hydraulic medium remains in a relatively closed and controllable hydraulic transmission environment, while external water flows only within the internal water-permeable area of ​​the shell and participates in buoyancy regulation. Furthermore, external water can enter or exit the side of the first piston away from the sealed hydraulic chamber under the action of the power component, driving the first piston to move. The absence of contact between the hydraulic medium and external water prevents dilution, contamination, or emulsification by the pool water, and also prevents leakage of the hydraulic medium into the pool water. To achieve this isolation, a sealing fit can be provided between the first and second pistons and their respective chamber walls. The connection of the sealed hydraulic chamber can utilize gaskets, threaded seals, welded seals, adhesive seals, or a one-piece molded structure.

[0094] The cross-sectional area of ​​the first piston can be set to be smaller than that of the second piston. The cross-sectional area can be understood as the effective pressure-bearing area of ​​the first and second pistons in the direction of hydraulic pressure. When the hydraulic medium in the sealed hydraulic chamber transmits pressure from the first piston side to the second piston side, because the effective pressure-bearing area of ​​the second piston is larger than that of the first piston, the second piston can generate a relatively larger output thrust under the same pressure. In this way, the power component does not need to directly output a mechanical thrust that is exactly the same as the compression resistance of the closed-cell foam buoyancy component. Instead, it can drive the first piston through external water, and through the area coordination between the first piston, the sealed hydraulic chamber, and the second piston, convert the smaller input-side action into a larger output-side action suitable for compressing the closed-cell foam buoyancy component. This configuration helps reduce the high-power requirements of the power component and allows the buoyancy control device to obtain sufficient compression capacity within the limited space of a small swimming pool cleaning robot.

[0095] The power unit can be used to drive external water into or out of the side of the first piston away from the sealed hydraulic chamber. When external water enters the side of the first piston away from the sealed hydraulic chamber, the first piston moves under water pressure, causing a change in the hydraulic pressure within the sealed hydraulic chamber. A pressure transmission relationship is formed between the first and second pistons to drive the second piston. When water is discharged from the side of the first piston away from the sealed hydraulic chamber, the water pressure on that side decreases, the hydraulic pressure within the sealed hydraulic chamber decreases, and the compression effect of the second piston on the closed-cell foam buoyancy component decreases or is released accordingly. The power unit can achieve the entry and discharge of external water through a water passage connected to the side of the first piston away from the sealed hydraulic chamber, or it can create hydraulic pressure changes by driving the first piston to change the effective volume of the sealed hydraulic chamber.

[0096] Understandably, in this embodiment, the second piston can function as a compression component or be driven by a compression component. When the second piston functions as a compression component, the side of the second piston facing the closed-cell foam buoyancy component can directly serve as the working surface, directly compressing the closed-cell foam buoyancy component as the second piston moves. This method results in a shorter force transmission path and a more compact structure, suitable for situations where the second piston and the closed-cell foam buoyancy component are arranged adjacent to each other. When the second piston is driven by a compression component, the second piston can drive the compression component to move via a push rod, pressure plate, connecting block, slider, or force transmission component, and then the compression component compresses the closed-cell foam buoyancy component. This method allows for a certain spatial misalignment or force surface conversion between the second piston and the closed-cell foam buoyancy component, suitable for situations where the internal space of the shell is limited, the closed-cell foam buoyancy component has an irregular shape, or an increased compression force area is required.

[0097] By employing a hydraulic lever mechanism consisting of a first piston, a second piston, and a sealed hydraulic chamber, and isolating the sealed hydraulic chamber from the water-permeable area inside the shell, the hydraulic medium within the sealed hydraulic chamber transmits pressure only between the first and second pistons as a closed pressure transmission medium, without contacting external water entering through the water-permeable structure. Simultaneously, a power component drives external water into or out of the side of the first piston away from the sealed hydraulic chamber, causing the external water to drive the first piston. The first piston regulates the hydraulic pressure within the sealed hydraulic chamber, driving the second piston to output the force used to compress the closed-cell foam buoyancy component. This allows the external water to drive the first piston while preventing debris such as mud, hair, and leaf debris from entering the sealed hydraulic chamber, thus avoiding hydraulic medium contamination, piston wear, jamming, or seal failure. Furthermore, the closed hydraulic transmission enables smooth compression of the closed-cell foam buoyancy component, reducing the space and driving capacity requirements of direct mechanical high-thrust structures and improving the operational reliability of the buoyancy control device in long-term aquatic environments.

[0098] In one example embodiment of this disclosure, the ratio of the cross-sectional area of ​​the second piston to that of the first piston can be from 1.5:1 to 10:1. When the first piston moves under the action of the hydraulic medium, the second piston compresses the closed-cell foam buoyancy component with an output thrust greater than the input thrust of the first piston.

[0099] In this design, the cross-sectional area of ​​the first piston can be denoted as the first cross-sectional area, and the cross-sectional area of ​​the second piston can be denoted as the second cross-sectional area. The second cross-sectional area can be larger than the first cross-sectional area, and the ratio between the second and first cross-sectional areas falls within the range of 1.5:1 to 10:1. This range indicates that the pressure-bearing area of ​​the second piston is amplified relative to that of the first piston, allowing the second piston to obtain a relatively larger output thrust when the hydraulic medium transmits pressure between the two pistons.

[0100] The ratio of the cross-sectional area of ​​the second piston to that of the first piston can be achieved by changing the diameter, width, length, or end-face shape of the first and second pistons. For example, when both the first and second pistons are circular, the effective diameter of the second piston can be set to be larger than that of the first piston, so that the cross-sectional area of ​​the second piston is in a ratio of 1.5:1 to 10:1. When both the first and second pistons are rectangular or elongated pistons, the effective width and effective length of the second piston can be adjusted to make its pressure-bearing area larger than that of the first piston. The cross-sectional area ratio of the first and second pistons can also be designed in conjunction with the internal space of the housing. For example, when the length space inside the pool cleaning robot is relatively sufficient but the height space is limited, an elongated second piston can be used; when the local space is relatively regular, a circular or near-circular second piston can be used. This embodiment does not impose any special limitations on this.

[0101] Understandably, when the ratio of the cross-sectional area of ​​the second piston to that of the first piston is maintained at 1.5:1 to 10:1, the second piston will compress the closed-cell foam buoyancy component with an output thrust greater than the input thrust of the first piston when the first piston moves under the action of the hydraulic medium. The working principle is that the hydraulic medium in the sealed hydraulic chamber can transmit the pressure formed on the first piston side to the second piston side. Ignoring friction losses and the slight compressibility of the hydraulic medium, the pressure on the first piston side and the pressure on the second piston side can be approximately the same, and the thrust generated by the piston is related to its effective pressure-bearing area. Therefore, when the cross-sectional area of ​​the second piston is larger than that of the first piston, the second piston can generate an output thrust greater than the input thrust of the first piston under the same hydraulic pressure. In this way, the power component does not need to directly provide all the mechanical thrust sufficient to compress the closed-cell foam buoyancy component; instead, it can first act on the first piston with a smaller cross-sectional area, and then transmit it to the second piston with a larger cross-sectional area via the hydraulic medium, allowing the second piston to output a larger thrust suitable for compressing the closed-cell foam buoyancy component.

[0102] In this embodiment, the ratio of the cross-sectional area of ​​the second piston to that of the first piston is set to 1.5:1 to 10:1, which balances the thrust amplification effect and the mechanism's stroke. If this ratio is too small, the thrust amplification capability of the second piston relative to the first piston is limited, and the power component still needs to provide a large input thrust, making it difficult to fully utilize the hydraulic lever mechanism's function of reducing the power component's output requirements. If this ratio is too large, although the second piston can obtain a larger output thrust, under the hydraulic medium's volume conservation relationship, the second piston's stroke will be correspondingly reduced, or the first piston needs to generate a large stroke to drive the second piston to complete a sufficient displacement, which may increase the drive stroke, response time, or the difficulty of internal housing arrangement. Therefore, a cross-sectional area ratio of 1.5:1 to 10:1 can achieve a good balance between output thrust, stroke, and structural compactness, enabling the hydraulic lever mechanism to provide the force required to compress the closed-cell foam buoyancy component without causing stroke configuration difficulties due to an excessively large area ratio.

[0103] Understandably, when the second piston compresses the closed-cell foam buoyancy component with an output thrust greater than the input thrust of the first piston, the magnitude of the output thrust can be pre-matched based on the material hardness, pressure area, target compression degree, and internal installation space of the closed-cell foam buoyancy component. For closed-cell foam buoyancy components with high hardness or large thickness, a relatively large cross-sectional area ratio can be selected within the range of 1.5:1 to 10:1 to obtain higher compression thrust; for closed-cell foam buoyancy components with low hardness or small volume, a relatively small cross-sectional area ratio can be selected to reduce the required stroke of the first piston and improve the action response speed.

[0104] By setting the ratio of the cross-sectional area of ​​the second piston to that of the first piston to be between 1.5:1 and 10:1, the smaller input thrust on the first piston side can be transmitted to the second piston side via hydraulic pressure to form a larger output thrust. This allows the compression requirements of the closed-cell foam buoyancy component to be met even within a pool cleaning robot where the size and power of the power components are limited. At the same time, this ratio range can avoid insufficient force amplification due to an excessively small area difference, and also avoid insufficient stroke of the second piston or excessive structural size due to an excessively large area difference, thus improving the practicality and compactness of the hydraulic force amplification structure.

[0105] In one example embodiment of this disclosure, the power component may include a gear pump, which delivers external water to the side of the first piston away from the sealed hydraulic chamber by forward operation and discharges the water from the side of the first piston away from the sealed hydraulic chamber by reverse operation; or, the power component may include a water pump and a reversing valve, which switches the flow direction of the external water relative to the side of the first piston away from the sealed hydraulic chamber through the reversing valve.

[0106] A gear pump is a positive displacement pump that continuously transports external water within its pump chamber through the rotation of meshing gears, converting rotational motion into directional flow of external water. The gear pump can be at least partially housed within the casing and connected via inlet and outlet to the side of the first piston away from the sealed hydraulic chamber. This allows external water output from the gear pump to enter the side of the first piston away from the sealed hydraulic chamber, or vice versa. The gear pump can be an external gear pump, an internal gear pump, or a miniature gear pump suitable for miniaturization. Its pump body, gears, bearings, and sealing structure can be selected based on the internal space of the pool cleaning robot and the external water transport requirements. In some embodiments, the gear pump can employ a pump body structure capable of outputting stable and continuous pressure within a miniaturized structure. Alternatively, a miniature plunger pump, a miniature vane pump, or other positive displacement hydraulic pump can be used to provide hydraulic driving force for the compression of closed-cell foam buoyancy components within a limited installation space.

[0107] The gear pump can deliver external water to the side of the first piston away from the sealed hydraulic chamber through forward operation. Forward operation can be understood as the gear pump operating in a predetermined first rotational direction (such as clockwise), allowing external water to be delivered from outside the casing, the inlet area, or the inlet channel to the side of the first piston away from the sealed hydraulic chamber. After the external water enters the side of the first piston away from the sealed hydraulic chamber, it applies water pressure to the first piston, causing it to move and adjust the hydraulic pressure within the sealed hydraulic chamber, thereby driving the output side of the hydraulic lever mechanism to produce a compression action. The forward operation time, speed, and output flow rate of the gear pump can be set according to the required compression amount of the closed-cell foamed buoyancy component; when a faster compression action is required, the speed of the gear pump can be increased or the forward operation time can be extended; when a smoother change in buoyancy is required, a lower speed or segmented forward operation mode can be used. Since gear pumps are volumetric pumping structures, the flow of external water and the rotation of gears have a clear correspondence, which helps to improve the controllability of water pressure changes on the side of the first piston away from the sealed hydraulic chamber, pressure changes in the sealed hydraulic chamber, and compression of the closed-cell foam buoyancy component.

[0108] The gear pump can discharge water from the side of the first piston away from the sealed hydraulic chamber by reversing its rotation. Reversing the rotation can be understood as the gear pump operating in a second rotational direction opposite to the forward rotation (e.g., counterclockwise), causing the water on the side of the first piston away from the sealed hydraulic chamber to flow in the opposite direction. This reduces the water pressure on the side of the first piston away from the sealed hydraulic chamber, and correspondingly reduces the hydraulic pressure within the sealed hydraulic chamber. As the pressure in the sealed hydraulic chamber decreases, the compression effect of the hydraulic lever mechanism on the closed-cell foam buoyancy component weakens, allowing the closed-cell foam buoyancy component to gradually recover. The reverse rotation can use the same or different rotation speed as the forward rotation, and can also be adjusted according to the recovery speed of the closed-cell foam buoyancy component and the water discharge requirements; this embodiment is not limited to this.

[0109] Of course, the power components can also include a water pump and a directional valve. The water pump uses the directional valve to switch the flow direction of the external water relative to the side of the first piston away from the sealed hydraulic chamber. A water pump refers to a pump body used to provide the power for the flow of external water; it can be a gear pump, piston pump, vane pump, or other pump-like structures capable of transporting external water. A directional valve can be understood as a valve used to change the flow path of the external water. It can connect the output end of the water pump to the side of the first piston away from the sealed hydraulic chamber, or connect the side of the first piston away from the sealed hydraulic chamber to the drainage path, by changing the position of the valve core, switching the valve plates, or changing the flow path connection. The directional valve can be an electromagnetically driven, mechanically driven, or electrically driven valve, and can be selected according to the water pump's flow rate, the volume of the water action area on the side of the first piston away from the sealed hydraulic chamber, and the control response requirements. By cooperating with the water pump and the directional valve, even if the water pump itself does not have reverse delivery capability, the directional valve can still be used to achieve water intake, drainage, or flow direction switching of the external water relative to the side of the first piston away from the sealed hydraulic chamber.

[0110] When the directional valve switches to the first open state, the external water output by the pump can be guided to the side of the first piston away from the sealed hydraulic chamber, increasing the water pressure on that side and pushing the first piston to move. This, in turn, increases the hydraulic pressure within the sealed hydraulic chamber and drives the hydraulic lever mechanism to compress. When the directional valve switches to the second open state, the water on the side of the first piston away from the sealed hydraulic chamber can be guided to the drainage path or discharged by the pump, reducing the water pressure on that side and lowering the hydraulic pressure within the sealed hydraulic chamber, thereby relieving the compression effect on the closed-cell foamed buoyancy component. The switching action of the directional valve can be coordinated with the start and stop of the pump, or it can change the flow direction of the external water while the pump is continuously running. For scenarios requiring rapid sinking and floating, the water pressure transition time can be shortened by increasing the switching response speed of the directional valve; for scenarios requiring stable buoyancy, the water pressure on the side of the first piston away from the sealed hydraulic chamber can be gradually changed by controlling the opening degree or switching rhythm of the directional valve. Therefore, the combination of water pump and reversing valve can improve the adaptability of the buoyancy control device to different buoyancy action requirements while maintaining the stability of hydraulic transmission.

[0111] By setting the power component as a gear pump capable of transporting external water in both directions, or as a structure combining a water pump and a reversing valve, the entry and exit of external water relative to the side of the first piston away from the sealed hydraulic chamber can be achieved through pump reversal or valve switching. This provides a clear flow direction control relationship for the reciprocating drive of the first piston, the rise and fall of hydraulic pressure in the sealed hydraulic chamber, and the compression and release of the closed-cell foamed buoyancy component. This configuration can utilize external water to adjust the driving pressure on the first piston side while maintaining the closed pressure transmission state of the hydraulic medium in the sealed hydraulic chamber. This reduces the need for complex mechanical transmission mechanisms or multiple power sources, lowers the risk of external water entering the sealed hydraulic chamber and causing contamination, jamming, or seal failure, and facilitates compact, low-noise, and reliable buoyancy adjustment.

[0112] In an optional embodiment of this disclosure, the drive assembly may further include a return spring disposed between the second piston and the closed-cell foam buoyancy member; wherein, when the second piston moves toward the closed-cell foam buoyancy member and compresses the closed-cell foam buoyancy member, the return spring is compressed and stores elastic potential energy; when the hydraulic pressure in the sealed hydraulic chamber decreases, the return spring releases elastic potential energy to push the second piston to reset and / or assist the closed-cell foam buoyancy member to recover.

[0113] A return spring is an elastic element that stores elastic potential energy when compressed and releases it after the external compression is reduced or released. For example, a return spring can be a helical compression spring, wave spring, disc spring, leaf spring combination, or other elastic structures capable of generating restoring force in the direction of compression. The material of the return spring can be stainless steel, spring steel, corrosion-resistant alloy, engineering plastic elastic parts, or corrosion-resistant metal elastic parts to adapt to the long-term use conditions of pool cleaning robots in humid or near-water environments. The stiffness, free length, wire diameter, number of coils, and maximum compression of the return spring can be set according to the stroke of the second piston, the compression resistance of the closed-cell foam buoyancy component, and the required recovery speed. This ensures that the return spring can store sufficient elastic potential energy during compression without significantly increasing the driving force required for the drive assembly to compress the closed-cell foam buoyancy component due to excessive stiffness.

[0114] A return spring can be positioned between the second piston and the closed-cell foam buoyancy component. This arrangement places the return spring between the output end of the hydraulic lever mechanism and the closed-cell foam buoyancy component, allowing it to directly participate in the force transmission process between the second piston and the closed-cell foam buoyancy component. One end of the return spring can abut against or connect to the side of the second piston facing the closed-cell foam buoyancy component, while the other end can abut against or connect to the closed-cell foam buoyancy component, the compression component, the pressure plate, or a force-bearing component adjacent to the closed-cell foam buoyancy component. The return spring can be positioned in the central region of the second piston or in the circumferential edge region of the second piston. When the force-bearing area of ​​the closed-cell foam buoyancy component is large, multiple return springs can be used, spaced apart along the working surface of the second piston to improve the uniformity of force distribution. By placing the return spring between the second piston and the closed-cell foam buoyancy component, the compression action of the second piston on the closed-cell foam buoyancy component can be transmitted through the return spring. Simultaneously, the return spring can also directly act on the second piston and the closed-cell foam buoyancy component during the release phase, improving the timeliness of the reset action.

[0115] As the second piston moves toward and compresses the closed-cell foam buoyancy component, the return spring is compressed and stores elastic potential energy. Specifically, when the hydraulic pressure within the sealed hydraulic chamber drives the second piston toward the closed-cell foam buoyancy component, the second piston first moves the return spring closer to the component, or transmits the compressive force to the component via the return spring. As the second piston continues to move, the closed-cell foam buoyancy component shrinks in volume, and the return spring is also compressed between the second piston and the component, thus converting some of the mechanical energy into elastic potential energy. The amount of compression of the return spring can be related to the displacement of the second piston, or it can be affected by the deformation of the closed-cell foam buoyancy component and the installation clearance.

[0116] When the hydraulic pressure within the sealed hydraulic chamber decreases, the return spring releases its elastic potential energy. This decrease in hydraulic pressure can occur when the power component reduces the input of hydraulic medium to the sealed hydraulic chamber, extracts hydraulic medium from the sealed hydraulic chamber, or the pressure within the sealed hydraulic chamber drops due to release control. At this time, the hydraulic pushing force on the second piston weakens, and the return spring returns from its compressed state to its extended state, converting its stored elastic potential energy into a pushing force. Since the return spring is located between the second piston and the closed-cell foam buoyancy component, when it releases its elastic potential energy, it can exert a force on the second piston away from the closed-cell foam buoyancy component, or it can exert an auxiliary restoring force on the closed-cell foam buoyancy component.

[0117] Understandably, closed-cell foam buoyancy components can recover their volume based on the elastic recovery ability of their internal closed-cell air bubbles and the material matrix. However, under conditions of long-term use, low-temperature water environments, material aging, or prolonged compression, the recovery speed of closed-cell foam buoyancy components may decrease. By placing a return spring between the second piston and the closed-cell foam buoyancy component, it can provide assistance to the component when the hydraulic pressure decreases, enabling it to transition from a compressed state to a recovered state more quickly. This auxiliary recovery action does not replace the elastic recovery of the closed-cell foam buoyancy component itself, but rather provides additional restoring force during its recovery process, making the volume recovery process of the closed-cell foam buoyancy component more stable and thus improving the buoyancy recovery speed.

[0118] The return spring can be used simultaneously to push the second piston back to its original position and to assist the closed-cell foam buoyancy component in restoring its original shape, or it can primarily perform one of these functions depending on the structural arrangement. When the two ends of the return spring directly or indirectly abut against the second piston and the closed-cell foam buoyancy component respectively, the return spring will generate a separating force between the second piston and the closed-cell foam buoyancy component during its extension, thereby simultaneously pushing the second piston back and causing the closed-cell foam buoyancy component to restore its volume. When the return spring is fixedly engaged with one side through a support or limiting member, its main restoring effect can be concentrated on either the second piston's return or the closed-cell foam buoyancy component's restoration. By selecting different installation methods, the return spring can be adapted to different housing spaces, second piston strokes, and closed-cell foam buoyancy component shapes, improving the design flexibility of the drive assembly.

[0119] In addition, the return spring can provide backup restoring force when the hydraulic pressure in the sealed hydraulic chamber drops abnormally or the hydraulic system loses pressure. When the hydraulic pressure in the sealed hydraulic chamber is insufficient to maintain the compressed position of the second piston due to control release, depressurization, or other reasons, the return spring can release the stored elastic potential energy, causing the second piston to move in the reset direction and release the continuous compression on the closed-cell foam buoyancy component.

[0120] In some embodiments, if the compression component is a push rod, a return spring can also be disposed between the push rod and the closed-cell foam buoyancy component. The return spring can be sleeved on the outer periphery of the push rod, disposed between the end of the push rod and the closed-cell foam buoyancy component, or disposed between the pressure plate connected to the end of the push rod and the closed-cell foam buoyancy component. By disposing the return spring between the push rod and the foam component, when the push rod moves toward the closed-cell foam buoyancy component, it can drive the return spring to be compressed synchronously, allowing the return spring to store elastic potential energy in the axial force transmission path of the push rod.

[0121] By setting a return spring between the second piston and the closed-cell foam buoyancy component, the return spring synchronously stores elastic potential energy when the second piston compresses the closed-cell foam buoyancy component. After the pressure in the sealed hydraulic chamber decreases, the elastic potential energy is released to push the second piston to reset and / or assist the closed-cell foam buoyancy component to recover. This reduces the risk of the second piston remaining in the compressed position due to sealing friction, residual hydraulic pressure, or guide resistance, reduces permanent deformation caused by long-term pressure on the closed-cell foam buoyancy component, and improves the response speed and recovery reliability of the release action.

[0122] In one example embodiment of this disclosure, multiple sets of closed-cell foam buoyancy components and drive components are arranged at intervals along the circumference or axial direction of the pool cleaning robot to synchronously or independently adjust the buoyancy of the pool cleaning robot.

[0123] The term "multiple sets" can be understood as at least two sets of buoyancy adjustment units that work independently or collaboratively. Each buoyancy adjustment unit may include a closed-cell foam buoyancy component and a corresponding drive component. Multiple closed-cell foam buoyancy components can have the same volume, material, and compressibility to produce a more balanced buoyancy change during synchronous operation. They can also be configured with different sizes or shapes according to the space size and buoyancy requirements of different areas of the pool cleaning robot to adapt to irregular installation spaces within the robot body.

[0124] Multiple drive components can each correspond to multiple closed-cell foam buoyancy components, enabling each drive component to compress or release its corresponding closed-cell foam buoyancy component. In some embodiments, a single drive component can drive multiple local compression components via a branch transmission structure, but each closed-cell foam buoyancy component still participates in buoyancy adjustment as multiple structural groups. By setting multiple groups of closed-cell foam buoyancy components and multiple drive components, the buoyancy control device no longer relies on a single large-volume buoyancy component to complete all buoyancy changes, but can distribute the buoyancy adjustment amount to multiple locations, thereby improving the layout flexibility of the device within a limited body space.

[0125] Multiple sets of closed-cell foam buoyancy components and multiple sets of drive components can be arranged circumferentially around the pool cleaning robot. Circumferential arrangement can be understood as a direction surrounding the robot's center, center of gravity, or a pre-defined central axis, or as a direction distributed along the outer perimeter, left and right sides, or front and back sides. In this circumferential arrangement, the multiple sets of closed-cell foam buoyancy components can be positioned on the left, right, front, rear, or corner areas of the pool cleaning robot, distributing buoyancy adjustment across different peripheral locations. Installation gaps, water passage gaps, or structural reinforcement gaps can be reserved between adjacent sets of closed-cell foam buoyancy components to prevent interference during compression and recovery. Through this circumferential arrangement, the multiple sets of closed-cell foam buoyancy components can provide buoyancy variations at different lateral positions of the pool cleaning robot, preventing buoyancy adjustment from concentrating in a single area, thus reducing the risk of attitude deviation caused by sudden changes in buoyancy on one side.

[0126] Of course, multiple sets of closed-cell foam buoyancy components and multiple sets of drive components can also be arranged at intervals along the axial direction of the pool cleaning robot. This axial direction can be the front-to-back direction, the length direction, the direction of travel, or the direction consistent with the main structural axis of the robot. When arranged at intervals along the axial direction, multiple sets of closed-cell foam buoyancy components can be placed in at least two positions among the front, middle, and rear of the robot, distributing the buoyancy adjustment effect along the robot's direction of travel. For longer pool cleaning robots, arranging multiple sets of closed-cell foam buoyancy components along the axial direction can fully utilize the internal space in the front-to-back direction of the robot, reducing the installation difficulties caused by excessively large individual closed-cell foam buoyancy components. For structures that need to maintain a relatively stable pitch posture in water, axially spaced arrangement can also make buoyancy changes in the front and rear areas more controllable, thereby reducing posture changes such as head tilting up and tail sinking caused by buoyancy concentrated at the front or rear.

[0127] Optionally, multiple sets of closed-cell foam buoyancy components and multiple sets of drive components can be arranged in combination along the circumferential and axial directions. For example, closed-cell foam buoyancy components and corresponding drive components can be set at the front left, front right, rear left, and rear right positions of the pool cleaning robot, or multiple buoyancy adjustment units can be arranged along the front-rear direction on both sides of the body. For pool cleaning robots with components such as batteries, cleaning components, motors, and filter chambers inside the body, multiple sets of closed-cell foam buoyancy components can be distributed in different gap areas according to the remaining space, and the corresponding drive components can be set close to each closed-cell foam buoyancy component. Through this distributed arrangement, the buoyancy control device can avoid occupying a single continuous large space and can be adapted to the existing structure of the pool cleaning robot, which is conducive to improving the utilization rate of the internal space of the whole machine.

[0128] Synchronous adjustment can be understood as multiple sets of drive components performing actions in the same direction at the same or nearly the same time. For example, simultaneously compressing or releasing corresponding closed-cell foam buoyancy components. During synchronous adjustment, the volume changes of each closed-cell foam buoyancy component follow a consistent trend, allowing the overall buoyancy of the pool cleaning robot to decrease or increase more uniformly. To achieve synchronous adjustment, multiple drive components can receive the same control signal, or they can achieve simultaneous action through mechanical linkage, a common power source, or a synchronous drive strategy. Synchronous adjustment is suitable for situations where the pool cleaning robot needs to sink or float as a whole. It helps maintain the stability of the robot's posture while changing the overall buoyancy, reducing roll or pitch fluctuations caused by rapid changes in local buoyancy.

[0129] Of course, the buoyancy of the pool cleaning robot can also be adjusted independently by multiple sets of closed-cell foam buoyancy components and multiple sets of drive components. Independent adjustment can be understood as different drive components being able to control the compression or release state of the corresponding closed-cell foam buoyancy components, so that the closed-cell foam buoyancy components at different locations have the same or different degrees of volume change. During independent adjustment, only some closed-cell foam buoyancy components can be compressed or released, or multiple sets of closed-cell foam buoyancy components can work with different compression amounts or different action sequences. Through independent adjustment, the buoyancy contribution at different locations can be configured differently according to the posture, load distribution, or working area requirements of the pool cleaning robot. For example, when one side of the robot body is more prone to sinking due to the weight distribution of internal components or the action of water flow, the closed-cell foam buoyancy component corresponding to that side can be kept to maintain a higher buoyancy contribution; when it is necessary to enhance the sinking tendency of a certain area, the closed-cell foam buoyancy component corresponding to that area can be compressed first.

[0130] By setting closed-cell foam buoyancy components and drive components in multiple groups and arranging them at intervals along the circumference or axis of the pool cleaning robot, the buoyancy adjustment effect can be distributed in different areas of the machine body, rather than concentrated in a single position. This can improve the overall buoyancy adjustment range and internal space utilization. When adjusted synchronously, the overall buoyancy can be changed more evenly. When adjusted independently, the buoyancy distribution in the front-to-back or left-to-right areas can be improved, reducing the risk of roll and pitch deviation and improving the stability of the robot in different cleaning postures.

[0131] In one example embodiment of this disclosure, the buoyancy control device may further include a controller connected to the drive assembly and used to control the degree to which the drive assembly compresses or releases the closed-cell foam buoyancy component according to buoyancy control instructions.

[0132] The controller can be understood as a control unit that receives detection signals for buoyancy control commands and outputs drive control signals. It may include at least one of a processor, memory, drive circuit, signal acquisition circuit, and power management circuit. The controller can be implemented using a microcontroller unit (MCU), a single-chip microcomputer, an embedded processor, or a dedicated control circuit, or it can be integrated into the overall control board of the pool cleaning robot. The controller can store buoyancy control commands, the operating range of the drive components, and buoyancy state judgment rules, and determine the control quantity of the drive components based on the buoyancy control commands. The controller can be housed in an electrical control chamber isolated from the water, or it can be connected to other components of the buoyancy control device through potting, a sealed box, or waterproof connectors to improve its operational reliability in the aquatic environment of the pool cleaning robot.

[0133] The buoyancy control command can be used to characterize at least one control requirement of the pool cleaning robot, including surfacing, sinking, maintaining a constant depth, keeping the current buoyancy state, or switching operating modes. The buoyancy control command can be input by the user through a mobile terminal, remote control, the control panel of the pool cleaning robot, or a cloud control platform, or it can be automatically generated by the overall control program of the pool cleaning robot based on the current cleaning task, operating mode, obstacle avoidance status, battery status, or recovery status. For example, when the user needs the pool cleaning robot to return to the surface, the buoyancy control command can instruct the robot to surface; when the robot needs to enter the pool bottom cleaning mode, the buoyancy control command can instruct the robot to sink; when the robot needs to perform waterline cleaning or constant depth cruising, the buoyancy control command can indicate the target water depth or target water depth range; when the robot detects an obstacle or needs to cross different cleaning areas, the buoyancy control command can also instruct the robot to temporarily adjust its buoyancy state. This embodiment does not impose any special limitations on this.

[0134] The controller can be connected to the drive component and used to output control signals to the drive component. This connection can include a power supply connection, a drive signal connection, an actuator control connection, or a status feedback connection. The controller can control the start / stop, direction of movement, output intensity, or duration of the drive component through the drive circuit, causing the drive component to compress or release the closed-cell foam buoyancy component. The controller can also receive status feedback signals from the drive component, such as position feedback, stroke feedback, current feedback, or pressure feedback, to determine whether the drive component has completed the expected action.

[0135] Understandably, the degree of compression or release of the closed-cell foam buoyancy component can be adjusted by the action time, speed, output force, output displacement, or holding position of the drive component. The controller can establish a correspondence between buoyancy control commands and drive component action parameters in preset control tables, formulas, or logic. For example, when the buoyancy control command indicates sinking, the controller can control the drive component to move in the compression direction, reducing the volume of the closed-cell foam buoyancy component; when the buoyancy control command indicates rising, the controller can control the drive component to move in the release direction, restoring the closed-cell foam buoyancy component and increasing its volume; when the buoyancy control command indicates maintaining the current buoyancy state, the controller can control the drive component to maintain its current position or output state. The controller can also set the maximum compression and maximum release degrees to prevent the closed-cell foam buoyancy component from being over-compressed or the drive component from exceeding its safe stroke.

[0136] In some alternative embodiments, where feedback control based on water depth is required, the buoyancy control device may further include a water depth sensor for detecting the current water depth of the pool cleaning robot, and the controller may provide feedback control to the drive components based on the buoyancy control command and the current water depth.

[0137] By configuring a controller that adjusts the compression or release of the closed-cell foam buoyancy component based on buoyancy control commands, buoyancy adjustment is no longer a fixed action. Instead, it can respond to different control requirements, such as user commands, working mode switching commands, surfacing commands, sinking commands, constant depth suspension commands, or obstacle avoidance commands. In scenarios where the user needs the robot to return to the water surface, dive to the target area, switch to waterline cleaning, or perform buoyancy obstacle avoidance, the controller can adapt and control the volume change of the closed-cell foam buoyancy component according to the buoyancy control commands. This reduces action lag or overshoot caused by mismatch between buoyancy actions and actual control requirements, improving the flexibility and operational stability of the pool cleaning robot's buoyancy control in different operating scenarios such as pool bottom, side walls, waterline, and surface return.

[0138] It should be noted that although several modules or units of the buoyancy control device of the pool cleaning robot have been mentioned in the detailed description above, this division is not mandatory. In fact, according to embodiments of this disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0139] In addition, a pool cleaning robot is also provided in this example embodiment, see reference. Figure 4As shown, the pool cleaning robot 400 may include a body 410, a cleaning component 420, a walking component 430, and a buoyancy control device 100 in this embodiment of the present disclosure, wherein: The body 410 serves as the main load-bearing structure of the pool cleaning robot 400, housing the cleaning component 420, the walking component 430, and the buoyancy control device 100, and providing structural support and protective space for each functional component. The body may include a bottom shell, top cover, side shells, internal support frame, mounting cavity, and functional areas for accommodating electrical control components or cleaning components. The body's shape can be configured as flat, box-shaped, streamlined, or other structures suitable for movement in water and attachment to cleaning surfaces, depending on the pool cleaning robot's operating method. The body can be made of plastic, composite materials, or a combination of a metal frame and plastic shell to balance underwater corrosion resistance, structural strength, and overall weight. Since the buoyancy control device needs to participate in the overall buoyancy adjustment of the pool cleaning robot, the body can have reserved installation space matching the buoyancy control device, ensuring that this installation space has adequate water communication with the external water body, thereby guaranteeing that the buoyancy control device can play a buoyancy adjustment role within the overall structure.

[0140] A cleaning component 420 can be installed on the body 410 for cleaning the pool. The cleaning component can be a roller brush, side brush, scraper, suction port, filter chamber, water flow channel, cleaning pump, or other structures capable of cleaning the pool bottom, sidewalls, or waterline area, depending on the specific type of pool cleaning robot. The cleaning component can be installed at the bottom of the body to clean sediment from the pool bottom as the robot moves along the pool; it can also be installed on the side or front of the body to clean attachments or corner areas near the sidewalls and waterline. The cleaning method of the cleaning component can be mechanical scrubbing, water flow adsorption, negative pressure suction, filtration collection, or a combination of these methods. By installing the cleaning component on the body, the pool cleaning robot can approach different cleaning areas driven by the walking component and use the cleaning component to remove, collect, or filter dirt, providing a basis for multi-area cleaning operations.

[0141] The walking assembly 430 can be installed on the body 410 to drive the pool cleaning robot 400 to move within the pool. The walking assembly can include tracks, drive wheels, driven wheels, rollers, guide wheels, underwater propulsion structures, or other structures capable of moving the body in water or on the pool cleaning surface. For pool cleaning robots that primarily move on the pool bottom or sidewall surfaces, the walking assembly can use tracks or drive wheels to improve contact stability with the cleaning surface; for pool cleaning robots that need to change position or posture in the water, the walking assembly can also be used in conjunction with a water propulsion component. The walking assembly can be driven by a drive motor, and power is transmitted to the tracks or drive wheels via a reduction gear, drive shaft, or synchronous belt. Because the pool cleaning robot is affected by buoyancy, gravity, water flow resistance, and cleaning reaction force when moving in different water depths, the walking assembly, when used in conjunction with a buoyancy control device, allows the robot to gain both mobility and buoyancy adjustment capabilities, thereby better adapting to the cleaning needs of the pool bottom, sidewalls, and waterline areas.

[0142] The pool cleaning robot 400 may include the buoyancy control device 100 as described in this embodiment. The buoyancy control device 100 can be installed as an independent module on the body 410, or it can be integrated with a local structure within the body 410. The buoyancy control device can be located in the middle, sides, front, rear, or near the center of gravity of the body, making it easier to transmit its buoyancy adjustment effect to the overall buoyancy state. For pool cleaning robots that need to maintain stable posture, the buoyancy control device can be symmetrically arranged relative to the center of gravity of the body to reduce roll or pitch deviation caused by changes in buoyancy. For bodies with irregular internal spaces, the buoyancy control device can be installed in a way that avoids the placement of the battery, filter chamber, cleaning components, and walking components. By integrating the buoyancy control device into the pool cleaning robot, the robot can achieve buoyancy adjustment through its own structure during the cleaning process, without relying on external auxiliary equipment to complete the rising or sinking movements.

[0143] The buoyancy control device 100 can be located in water when the pool cleaning robot 400 is in both surface and underwater states. The surface state can be understood as the pool cleaning robot being at least partially near or floating near the pool surface, while the underwater state can be understood as the pool cleaning robot being entirely or primarily submerged below the water surface. The fact that the buoyancy control device is located in water in both surface and underwater states indicates that its working area does not need to be exposed to air, nor does it need to obtain outside air by emerging above the water surface to participate in buoyancy adjustment. To achieve this arrangement, the buoyancy control device can be located below the waterline within the robot body, or in an area where the robot remains submerged even when in the surface state. By ensuring that the buoyancy control device is located in water in both buoyancy and underwater states, the communication between the water inside and outside the shell is maintained throughout the buoyancy process, providing a stable working environment for the buoyancy control device when switching between surface and underwater states.

[0144] The shell of the buoyancy control device can be connected to the water outside the machine body via a water-permeable structure. This connection can be achieved by setting openings, through holes, grilles, water guide channels, or connecting areas opposite the water-permeable structure of the buoyancy control device at corresponding locations on the machine body, allowing external water to enter the shell of the buoyancy control device from the outside of the machine body, or to exit from the shell to the outside of the machine body. The connection path between the water-permeable structure and the water outside the machine body can be a direct connection or an indirect connection via a water guide cavity, transition cavity, or water flow channel inside the machine body. To prevent the water-permeable structure from being blocked by cleaning components, walking components, or internal support components, the connecting area on the machine body can be located in a position where water flow can easily enter, and large particles of debris can be blocked by grilles or protective structures. By connecting the shell of the buoyancy control device to the water outside the machine body, when the volume of the closed-cell foam buoyancy component changes, the water can flow between the outside of the robot and the inside of the shell, thus enabling the buoyancy adjustment function of the buoyancy control device to be realized in the entire machine's aquatic environment.

[0145] It should be noted that the robot body, cleaning components, locomotion components, and buoyancy control device can work collaboratively. The locomotion components propel the robot within the pool, the cleaning components clean the areas they pass through or target areas, and the buoyancy control device modifies the buoyancy of the pool cleaning robot in the water. When the robot needs to move from near the surface to the bottom, the buoyancy control device reduces the robot's buoyancy, making it easier for the locomotion components to contact the bottom and move forward. When the robot needs to move from the bottom to the surface or waterline, the buoyancy control device increases the robot's buoyancy, making it easier for the robot to rise to the target area. When the robot needs to maintain a cleaning posture in the middle depth area, the buoyancy control device maintains the appropriate buoyancy, allowing the cleaning components to perform cleaning within a relatively stable depth range. Through this structural collaboration, the pool cleaning robot can enhance its adaptability to multi-area pool cleaning scenarios without significantly increasing the need for independent buoyancy chambers or external auxiliary equipment.

[0146] The specific details of the buoyancy control device in the aforementioned pool cleaning robot have been described in detail in the embodiments of the buoyancy control device of the corresponding pool cleaning robot, and therefore will not be repeated here.

[0147] By integrating the body, cleaning components, walking components, and buoyancy control device into the pool cleaning robot, and ensuring that the buoyancy control device is located in the water in both surface and underwater states and is connected to the external water body through a water-permeable structure, the robot can directly adjust the buoyancy of the whole machine by utilizing the volume change of the closed-cell foam buoyancy component during the cleaning process. This allows it to float, sink, or suspend at a constant depth, reducing reliance on external auxiliary buoyancy structures, independent airbags, or complex water injection and drainage chambers. This improves the adaptability and structural integration of the pool cleaning robot for multi-area cleaning.

[0148] In addition, this example embodiment also provides a method for controlling the buoyancy of a pool cleaning robot. This method can be applied to a pool cleaning robot that includes a buoyancy control device. The pool cleaning robot may include a buoyancy control device, which may include a closed-cell foam buoyancy component, a drive assembly, and a shell that communicates with the external water body. The closed-cell foam buoyancy component may be disposed inside the shell.

[0149] Figure 5 This schematically illustrates a flow chart of a buoyancy control method for a pool cleaning robot according to some embodiments of the present disclosure, with reference to... Figure 5 As shown, the buoyancy control method may include the following steps: Step S510: When the pool cleaning robot is in an aquatic environment, a buoyancy control command is obtained; Step S520: According to the buoyancy control command, control the drive assembly to compress or release the closed-cell foam buoyancy component; wherein, when the buoyancy control command instructs the pool cleaning robot to sink, control the drive assembly to compress the closed-cell foam buoyancy component, reducing its volume and allowing external water to enter the shell, thereby reducing the buoyancy of the pool cleaning robot; when the buoyancy control command instructs the pool cleaning robot to float, control the drive assembly to release the closed-cell foam buoyancy component, restoring its original shape and increasing its volume, and expelling water from the shell, thereby increasing the buoyancy of the pool cleaning robot.

[0150] The aquatic environment can be understood as the state of the pool cleaning robot, or at least its buoyancy control device, within the pool water. For example, the aquatic environment can include the state of the pool cleaning robot near the water surface, near the pool bottom, near the side walls, or in the middle of the water. Buoyancy control commands can be used to characterize at least one control requirement of the pool cleaning robot, such as surfacing, sinking, maintaining a constant depth, maintaining current buoyancy, or switching operating modes. Buoyancy control commands can be input by the user through a mobile terminal, remote control, the pool cleaning robot's control panel, or a cloud control platform, or can be automatically generated by the pool cleaning robot's overall control program based on the current cleaning task, operating mode, obstacle avoidance status, battery status, or retrieval status.

[0151] The drive assembly can compress or release the closed-cell foam buoyancy component based on buoyancy control commands. This control process can be understood as selecting an action to reduce or increase the volume of the closed-cell foam buoyancy component according to the robot's actual buoyancy requirements. If the buoyancy control command instructs the pool cleaning robot to sink or move to a deeper position, the drive assembly is controlled to compress the closed-cell foam buoyancy component, reducing its volume; if the buoyancy control command instructs the pool cleaning robot to float or move to a shallower position, the drive assembly is controlled to release the closed-cell foam buoyancy component, restoring its volume and increasing it.

[0152] When the buoyancy control command instructs the pool cleaning robot to sink, it indicates that the robot needs to move to a deeper location or switch to a deeper cleaning area such as the pool bottom or lower sidewalls. In this case, the control drive component compresses the closed-cell foam buoyancy component, reducing its volume. With the reduced volume, the space occupied by the closed-cell foam buoyancy component inside the shell decreases, allowing external water to enter the shell through the connecting channel to fill the space released by the reduced volume of the buoyancy component. Since the space previously filled by the closed-cell foam buoyancy component is now occupied by water, the overall buoyancy of the pool cleaning robot decreases, causing the robot to tend to sink.

[0153] When the buoyancy control command instructs the pool cleaning robot to float, it indicates that the robot needs to move to a shallower area, return to the surface, or switch to a cleaning area near the waterline. At this time, the control drive component releases the closed-cell foam buoyancy component, causing it to recover and increase in volume. As the closed-cell foam buoyancy component recovers, it occupies more space inside the shell, pushing the water inside the shell out to the outside water through the water-permeable structure or other connecting areas. As the water volume inside the shell decreases and the space occupied by the closed-cell foam buoyancy component increases, the buoyancy experienced by the pool cleaning robot increases, thus causing the robot to tend to float.

[0154] By acquiring buoyancy control commands when the robot is in an aquatic environment, and controlling the drive components to compress or release closed-cell foam buoyancy components according to these commands, the buoyancy of the pool cleaning robot can be selectively reduced or increased based on different control requirements such as user operation, work mode switching, surfacing and returning, sinking for cleaning, fixed-depth suspension, or snorkeling and obstacle avoidance. Thus, when the buoyancy control command indicates sinking, the buoyancy can be reduced by compressing the closed-cell foam buoyancy components, allowing the robot to move to a deeper position; when the buoyancy control command indicates surfacing, the buoyancy can be increased by releasing the closed-cell foam buoyancy components, allowing the robot to move to the surface or a shallower position. This improves the matching degree between buoyancy control actions and actual operational needs, reduces action lag or overshoot caused by fixed buoyancy adjustment strategies, and enhances the initiative and adaptability of the pool cleaning robot in buoyancy control in different scenarios such as pool bottom cleaning, waterline cleaning, surface return, and obstacle avoidance.

[0155] In one example embodiment of this disclosure, it can be achieved through Figure 6 The steps described herein implement the control of the drive component to compress or release the closed-cell foam buoyancy component based on the buoyancy control command and the current water depth, as referenced. Figure 6 As shown, it can specifically include: Step S610: When the buoyancy control command indicates a target water depth, determine the water depth difference between the current water depth and the target water depth; Step S620: When the water depth difference is greater than a preset water depth threshold, the drive component is controlled to compress or release the closed-cell foam buoyancy component according to the relationship between the current water depth and the target water depth. Step S630: If the water depth difference is less than or equal to the preset water depth threshold, control the drive component to maintain the current state, or control the drive component to switch between compressing the closed-cell foam buoyancy component and releasing the closed-cell foam buoyancy component according to the preset switching frequency, so that the pool cleaning robot is maintained near the target water depth.

[0156] The depth difference can be understood as the degree of deviation of the pool cleaning robot's current depth from the target depth indicated by the buoyancy control command. It can be obtained by comparing the current depth and the target depth. In one implementation, the depth difference can be the absolute value of the difference between the current depth and the target depth, representing the extent to which the robot deviates from the target depth; the relationship between the current depth and the target depth indicates whether the robot is too shallow or too deep relative to the target depth. By using the target depth as a specific control content indicated by the buoyancy control command, it is possible to further achieve constant-depth suspension or target-depth maintenance control while maintaining the higher-level expression of the buoyancy control command.

[0157] When the depth difference exceeds a preset depth threshold, the drive component can be controlled to compress or release the closed-cell foam buoyancy component based on the relationship between the current water depth and the target water depth. The preset depth threshold can be understood as the allowable deviation range used to determine whether buoyancy adjustment is necessary. When the depth difference exceeds the preset depth threshold, it indicates that the pool cleaning robot's current depth has significantly deviated from the target water depth indicated by the buoyancy control command, requiring adjustment of the closed-cell foam buoyancy component to change the robot's buoyancy. The preset depth threshold can be set based on the pool cleaning robot's buoyancy response speed, the target cleaning area, the allowable depth deviation, and the drive component's operating frequency. For cleaning areas requiring high water depth maintenance accuracy, a smaller preset depth threshold can be set; for cleaning areas allowing some depth fluctuation, a larger preset depth threshold can be set to reduce unnecessary drive actions. The specific preset depth threshold can be customized according to actual conditions; this embodiment does not impose any special limitations on this.

[0158] When the difference in water depth exceeds a preset water depth threshold, the relationship between the current water depth and the target water depth is used to determine the direction of movement of the drive component. If the current water depth is less than the target water depth, it indicates that the pool cleaning robot is above or in a shallower position than the target water depth and needs to move to a deeper position. In this case, the drive component can be controlled to compress the closed-cell foam buoyancy component, reducing its volume and allowing external water to enter the shell, thereby reducing the buoyancy of the pool cleaning robot. If the current water depth is greater than the target water depth, it indicates that the pool cleaning robot is below or in a deeper position than the target water depth and needs to move to a shallower position. In this case, the drive component can be controlled to release the closed-cell foam buoyancy component, restoring its original shape and increasing its volume, and expelling water from the shell, thereby increasing the buoyancy of the pool cleaning robot.

[0159] When the depth difference is less than or equal to a preset depth threshold, it indicates that the pool cleaning robot is near the target depth, or the deviation between the current depth and the target depth is within an acceptable range. At this point, the drive components can be controlled to maintain their current state. Maintaining the current state can be understood as keeping the drive components in their current compressed, released, or intermediate position, ensuring the closed-cell foam buoyancy component maintains its current volume, thus keeping the robot's buoyancy relatively stable. By refraining from significant compression or release actions within the allowable deviation range, frequent movements of the drive components due to minor water depth fluctuations can be avoided, reducing energy consumption and mechanical wear, while also minimizing shaking or oscillation during buoyancy control.

[0160] When the water depth difference is less than or equal to a preset water depth threshold, the drive component can be controlled to switch between compressing and releasing the closed-cell foam buoyancy component according to a preset switching frequency, so that the pool cleaning robot remains near the target water depth. The preset switching frequency can be understood as the frequency at which the drive component switches between compression and release actions periodically or intermittently. It can be set according to the buoyancy inertia of the pool cleaning robot, the recovery speed of the closed-cell foam buoyancy component, the degree of water disturbance, and the target water depth maintenance requirements. By performing small compressions and releases according to the preset switching frequency, a slight compensation can be made for the buoyancy state when the pool cleaning robot is affected by water flow disturbances or the reaction force of cleaning actions, making it less likely for the pool cleaning robot to continuously deviate from the target water depth.

[0161] Depending on the specific operational scenario, the system can choose to maintain the current state or switch at a preset switching frequency. For example, if the water environment is relatively stable and the pool cleaning robot's posture changes minimally, the drive components can be prioritized to maintain the current state, reducing the number of actions required. If the water is turbulent, the pool cleaning robot is subjected to reaction forces from the cleaning components, or the robot tends to slowly drift near the target water depth, the drive components can be controlled to switch between compressing and releasing the closed-cell foam buoyancy components at a preset switching frequency. The preset switching frequency can be a fixed frequency or adjusted based on the robot's drift trend near the target water depth. For instance, when the pool cleaning robot tends to sink, the proportion of releasing the closed-cell foam buoyancy components can be appropriately increased; conversely, when the pool cleaning robot tends to rise, the proportion of compressing the closed-cell foam buoyancy components can be appropriately increased.

[0162] By determining the depth difference between the current water depth and the target water depth when the buoyancy control command indicates the target water depth, and comparing the depth difference with a preset water depth threshold, the robot will only perform a clear compression or release action when it deviates from the target water depth by more than the allowable range. When approaching the target water depth, it will maintain the current state or make small switches at a preset switching frequency. This reduces frequent malfunctions caused by water flow disturbances or sensor fluctuations, reduces the energy consumption and mechanical wear of the drive components, and improves the stability of the robot when it is suspended near the target water depth.

[0163] In one example embodiment of this disclosure, the drive assembly may include a power component, a first piston, a second piston, and a sealed hydraulic chamber connecting the first and second pistons; the compression of the closed-cell foam buoyancy component by the drive assembly can be controlled through the following steps, specifically including: The power unit can be controlled to drive external water into the side of the first piston away from the sealed hydraulic chamber, thereby pushing the first piston to move and adjusting the hydraulic pressure in the sealed hydraulic chamber. The hydraulic medium in the sealed hydraulic chamber drives the second piston to move toward the closed-cell foam buoyancy component to compress the closed-cell foam buoyancy component. The cross-sectional area of ​​the first piston is smaller than that of the second piston, and the second piston compresses the closed-cell foam buoyancy component with an output thrust greater than the input thrust of the first piston.

[0164] By controlling the power component during the compression control process to drive external water into the side of the first piston away from the sealed hydraulic chamber, the first piston is pushed to move, and the hydraulic medium drives the second piston with a larger cross-sectional area to move towards the closed-cell foam buoyancy component. This allows a smaller input thrust to be converted into a larger output compression thrust, thereby reducing the power and size requirements of the power component, while ensuring that the closed-cell foam buoyancy component can be reliably compressed. This improves the robot's responsiveness and structural compactness when it needs to sink.

[0165] In one example embodiment of this disclosure, the release of the closed-cell foam buoyancy component by the drive assembly can be controlled by the following steps, specifically including: The power component can be controlled to drive the water on the side of the first piston away from the sealed hydraulic chamber to be discharged, or the reversing valve can be controlled to switch the flow direction of the external water relative to the side of the first piston away from the sealed hydraulic chamber; wherein, after the water pressure on the side of the first piston away from the sealed hydraulic chamber decreases, the closed-cell foam buoyancy component pushes the second piston to reset by the elastic expansion force generated when it recovers itself.

[0166] The specific details of controlling the compression and release of the closed-cell foam buoyancy component in the above-mentioned buoyancy control method of the pool cleaning robot have been described in detail in the corresponding buoyancy control device of the pool cleaning robot, so they will not be repeated here.

[0167] By controlling the power component to drive the water on the side of the first piston away from the sealed hydraulic chamber during the release control process, or by controlling the reversing valve to switch the flow direction of the external water relative to the side of the first piston away from the sealed hydraulic chamber, the water pressure on the side of the first piston away from the sealed hydraulic chamber is reduced, and the hydraulic pressure in the sealed hydraulic chamber is reduced. The elastic expansion force generated when the closed-cell foam buoyancy component recovers itself is used to push the second piston to reset. Therefore, the release action can be completed without setting an additional active pull-back mechanism or air-filled reset structure, reducing structural complexity and improving the stability and long-term reliability of the robot's floating process.

[0168] In one example embodiment of this disclosure, the compression or release of the closed-cell foam buoyancy component by the drive assembly according to the buoyancy control command can be achieved through the following steps, specifically including: The operating direction and operating parameters of the drive component can be determined according to the floating and sinking control command. The operating direction may include the compression direction or the release direction, and the operating parameters may include at least one of the following: running time, running speed, output pressure and compression displacement; the operation of the drive component is controlled according to the operating direction and operating parameters.

[0169] The direction of operation can be understood as the direction in which the drive component should compress or release the closed-cell foam buoyancy component. For example, when the buoyancy control command instructs the pool cleaning robot to sink, the controller can determine that the drive component's direction of operation is compression, causing the drive component to compress the closed-cell foam buoyancy component; when the buoyancy control command instructs the pool cleaning robot to float, the controller can determine that the drive component's direction of operation is release, causing the drive component to release or reduce the compression effect on the closed-cell foam buoyancy component; when the buoyancy control command instructs to maintain the current buoyancy state, the controller can determine that the drive component should maintain the current direction of operation or stop operating.

[0170] Operating parameters can be used to limit the specific amplitude or intensity of the drive component's movement after the direction of operation is determined. For example, operating parameters may include at least one of the following: operating duration, operating speed, output pressure, and compression displacement. Operating duration can be understood as the duration of continuous movement of the drive component in the current direction; operating speed can be understood as the speed at which the output end of the drive component moves or the rate at which the drive component performs compression or release actions; output pressure can be understood as the pressure applied by the drive component to the closed-cell foam buoyancy component or the equivalent pressure transmitted to the closed-cell foam buoyancy component; and compression displacement can be understood as the displacement corresponding to the compression of the closed-cell foam buoyancy component by the drive component. The above operating parameters can be used individually or in combination. For example, the degree of volume change of the closed-cell foam buoyancy component can be controlled solely by the operating duration; the operation process of the drive component can be controlled simultaneously by combining the operating speed and compression displacement; and the maximum intensity of the compression action can be limited based on the output pressure to avoid over-compression of the closed-cell foam buoyancy component. This embodiment does not impose any special limitations on this.

[0171] In some embodiments, the controller can determine operating parameters based on the type of buoyancy control command. For example, when the buoyancy control command is a rapid sinking command, the controller can control the drive component to move at a higher operating speed, a longer operating time, or a larger compression displacement; when the buoyancy control command is a slow sinking command, the controller can control the drive component to move at a lower operating speed or a smaller compression displacement; when the buoyancy control command is a float-back command, the controller can control the drive component to move along the release direction, causing the closed-cell foam buoyancy component to quickly recover; when the buoyancy control command is a waterline cleaning mode switching command, the controller can control the drive component to release the closed-cell foam buoyancy component with a smaller amplitude, causing the robot's buoyancy to gradually increase.

[0172] In other embodiments, the controller can also adjust the operating parameters based on the current operating mode, the status of the walking component, the status of the cleaning component, the battery status, the posture status, or the obstacle detection results. For example, when the pool cleaning robot is cleaning the bottom of the pool and needs to increase its bottom-hugging stability, the compression degree of the closed-cell foam buoyancy component can be appropriately increased; when the pool cleaning robot needs to return to the surface for the user to retrieve, the release degree of the closed-cell foam buoyancy component can be appropriately increased; when the pool cleaning robot is near an obstacle or its posture changes significantly, the speed of the drive component can be reduced to avoid sudden changes in buoyancy affecting the robot's posture stability.

[0173] By determining the running direction of the drive component and at least one of the following operating parameters—running time, running speed, output pressure, and compression displacement—based on the buoyancy control command, the direction and intensity of the drive component's movement can be matched with control intentions such as buoyancy, sinking, maintaining the current buoyancy state, or switching operating modes. This reduces over-compression, over-release, and buoyancy overshoot, decreases ineffective movements of the drive component and fatigue wear of closed-cell foam buoyancy components, and improves the control accuracy and operational stability of the buoyancy control device in response to different buoyancy requirements.

[0174] It should be noted that although the steps of the method in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or a step may be broken down into multiple steps.

[0175] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the embodiments disclosed herein. This specification is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. It is understood that the specification and embodiments are to be considered exemplary only and are intended to illustrate the true scope and technical concepts of this disclosure.

[0176] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope.

Claims

1. A buoyancy control device for a swimming pool cleaning robot, characterized in that, include: A shell, wherein the shell is provided with a water-permeable structure, the water-permeable structure being used to connect the interior of the shell with an external water body; A closed-cell foamed buoyancy component is disposed within the shell, and the closed-cell foamed buoyancy component is a compressible and recoverable buoyancy component; A drive assembly, at least partially disposed within the housing, is used to compress or release the closed-cell foam buoyancy component. When the drive assembly compresses the closed-cell foam buoyancy component, the volume of the closed-cell foam buoyancy component decreases, and external water enters the shell through the water-passing structure, thereby reducing the buoyancy of the pool cleaning robot. When the drive assembly releases the closed-cell foam buoyancy component, the closed-cell foam buoyancy component recovers and increases in volume, and the water inside the shell is discharged through the water-passing structure, thereby improving the buoyancy of the pool cleaning robot.

2. The apparatus according to claim 1, characterized in that, The closed-cell foamed buoyancy component has multiple non-interconnected closed-cell air bubbles inside. Under the compression action of the driving assembly, the volume of each closed-cell foam buoyancy component is compressed, and the closed-cell foam buoyancy component deforms from a first volume to a second volume, wherein the second volume is smaller than the first volume; and After being released by the drive assembly, the closed-cell foamed buoyancy component recovers from the second volume to the first volume by relying on the elastic expansion force generated by the closed-cell bubbles during recovery.

3. The apparatus according to claim 2, characterized in that, The compression rate of the closed-cell foamed buoyancy component when it deforms from the first volume to the second volume is 30% to 50%; The volume of water entering or exiting the interior of the shell is related to the volume difference between the first volume and the second volume.

4. The apparatus according to claim 1, characterized in that, The driving component includes: Power components; A compression component, wherein the power component is connected to the compression component in a transmission manner, and the compression component is disposed opposite to the closed-cell foam buoyancy component; Specifically, when the power component drives the compression component to move toward the closed-cell foam buoyancy component, the driving component compresses the closed-cell foam buoyancy component, and when the compression component moves away from the closed-cell foam buoyancy component, the driving component releases the closed-cell foam buoyancy component.

5. The apparatus according to claim 4, characterized in that, The drive assembly further includes a hydraulic lever mechanism, which comprises: First piston; Second piston; A sealed hydraulic chamber is provided for connecting the first piston and the second piston. The sealed hydraulic chamber is isolated from the internal water-passing area of ​​the housing. The hydraulic medium in the sealed hydraulic chamber does not come into contact with external water that enters the housing through the water-passing structure. Wherein, the cross-sectional area of ​​the first piston is smaller than that of the second piston, the power component is used to drive external water into or out of the side of the first piston away from the sealed hydraulic chamber, so as to adjust the hydraulic pressure in the sealed hydraulic chamber through the first piston, the second piston constitutes the compression component, or the second piston is connected to the compression component in a transmission connection.

6. The apparatus according to claim 5, characterized in that, The ratio of the cross-sectional area of ​​the second piston to that of the first piston is 1.5:1 to 10:

1. When the first piston moves under the action of the hydraulic medium, the second piston compresses the closed-cell foam buoyancy component with an output thrust greater than the input thrust of the first piston.

7. The apparatus according to claim 5, characterized in that, The power component includes a gear pump, which, by rotating in the forward direction, delivers external water to the side of the first piston away from the sealed hydraulic chamber, and by rotating in the reverse direction, discharges the water from the side of the first piston away from the sealed hydraulic chamber; or... The power components include a water pump and a reversing valve. The water pump switches the flow direction of external water relative to the side of the first piston away from the sealed hydraulic chamber via the reversing valve.

8. The apparatus according to claim 5, characterized in that, The driving component also includes: A return spring is provided between the second piston and the closed-cell foam buoyancy component; When the second piston moves toward the closed-cell foam buoyancy member and compresses the closed-cell foam buoyancy member, the return spring is compressed and stores elastic potential energy. When the hydraulic pressure in the sealed hydraulic chamber decreases, the return spring releases the elastic potential energy to push the second piston to reset and / or assist the closed-cell foam buoyancy component to recover.

9. The apparatus according to claim 1, characterized in that, The closed-cell foam buoyancy components and the drive components are configured in multiple sets, and the multiple sets of closed-cell foam buoyancy components and the multiple sets of drive components are arranged at intervals along the circumference or axial direction of the pool cleaning robot to synchronously or independently adjust the buoyancy of the pool cleaning robot.

10. The apparatus according to claim 1, characterized in that, The buoyancy control device also includes: A controller, connected to the drive assembly, is used to control the degree to which the drive assembly compresses or releases the closed-cell foam buoyancy component according to a buoyancy control command; The buoyancy control command is used to characterize the pool cleaning robot to perform at least one control intention among floating, sinking, or maintaining the current buoyancy state.

11. A swimming pool cleaning robot, characterized in that, include: Organism; A cleaning component, disposed on the body, is used for cleaning the swimming pool; A walking component, disposed on the body, is used to drive the pool cleaning robot to move within the pool; The buoyancy control device as described in any one of claims 1 to 10 is located in water when the pool cleaning robot is in a surface state and an underwater state; The buoyancy control device is installed on the body of the robot. The housing of the buoyancy control device is connected to the water outside the body through the water passage structure. The buoyancy control device is used to adjust the buoyancy of the pool cleaning robot, so that the pool cleaning robot can perform floating, sinking or constant depth suspension.

12. A method for controlling the buoyancy and sinking of a swimming pool cleaning robot, characterized in that, The pool cleaning robot includes a buoyancy control device, which comprises a closed-cell foam buoyancy component, a drive assembly, and a shell communicating with the external water body. The closed-cell foam buoyancy component is disposed within the shell. The method includes: When the pool cleaning robot is in an aquatic environment, it acquires buoyancy control commands; According to the buoyancy control command, the drive component is controlled to compress or release the closed-cell foam buoyancy component; When the buoyancy control command is used to instruct the pool cleaning robot to sink, the drive assembly is controlled to compress the closed-cell foam buoyancy component, thereby reducing the volume of the closed-cell foam buoyancy component and allowing external water to enter the shell, thus reducing the buoyancy of the pool cleaning robot. When the buoyancy control command instructs the pool cleaning robot to float, the drive assembly is controlled to release the closed-cell foam buoyancy component, causing the closed-cell foam buoyancy component to recover and increase in volume, and causing the water inside the shell to be discharged, thereby increasing the buoyancy of the pool cleaning robot.

13. The method according to claim 12, characterized in that, The drive assembly includes a power component, a first piston, a second piston, and a sealed hydraulic chamber connecting the first piston and the second piston; The control of the drive assembly to compress the closed-cell foam buoyancy component includes: The power component is controlled to drive external water into the side of the first piston away from the sealed hydraulic chamber, so as to push the first piston to move and make the first piston adjust the hydraulic pressure in the sealed hydraulic chamber; The hydraulic medium in the sealed hydraulic chamber drives the second piston to move toward the closed-cell foam buoyancy component, thereby compressing the closed-cell foam buoyancy component; Wherein, the cross-sectional area of ​​the first piston is smaller than that of the second piston, and the second piston compresses the closed-cell foam buoyancy component with an output thrust greater than the input thrust of the first piston.

14. The method according to claim 13, characterized in that, The control of the drive assembly to release the closed-cell foam buoyancy component includes: The power component is controlled to drive the first piston to discharge water from the side away from the sealed hydraulic chamber, or the reversing valve is controlled to switch the flow direction of external water relative to the side of the first piston away from the sealed hydraulic chamber. When the water pressure on the side of the first piston away from the sealed hydraulic chamber decreases, the hydraulic pressure in the sealed hydraulic chamber decreases, and the closed-cell foamed buoyancy component pushes the second piston to reset by the elastic expansion force generated when it recovers.

15. The method according to claim 12, characterized in that, The step of controlling the drive assembly to compress or release the closed-cell foam buoyancy component according to the buoyancy control command includes: The operating direction and operating parameters of the drive component are determined according to the buoyancy control command. The operating direction includes either the compression direction or the release direction, and the operating parameters include at least one of the following: operating duration, operating speed, output pressure, and compression displacement. The drive component is controlled to operate according to the stated direction of operation and the stated operating parameters.

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