Amphibious robot

Abstract

The application provides an amphibious robot, which comprises a main frame, a flight assembly arranged above the main frame and comprising a plurality of rotor assemblies for enabling the amphibious robot to be in a vertical flight state or a horizontal flight state, and a land travel assembly arranged below the main frame and comprising a pair of drive assemblies, each of which comprises a land travel device for enabling the amphibious robot to travel on the ground and a linkage assembly for adjusting the position of the land travel device. The amphibious robot comprises a first center of mass, the land travel device comprises a second center of mass, the first center of mass and the pair of second centers of mass define a virtual plane, and when the amphibious robot is in the vertical flight state or the horizontal flight state, the linkage assembly adjusts the position of the land travel device so that the virtual plane is substantially vertical. Through the above arrangement, the amphibious robot can be kept stable in different postures or changes of postures, and energy consumption can be reduced.

Description

Technical Field

[0001] This invention relates to an amphibious robot. Background Technology

[0002] Multirotor drones have gained widespread application due to their rapid vertical takeoff and flexible aerial flight capabilities. However, they also suffer from high energy consumption, short flight time, and high noise levels, making it difficult to complete missions requiring long endurance and high stealth. Furthermore, when drones need to move extensively into confined spaces to perform specific tasks, space constraints prevent them from performing flight maneuvers, thus hindering their ability to complete the designated mission. Therefore, amphibious robots combining multirotor drones and mobile robots are receiving increasing research and application.

[0003] Specifically, documents such as CN115284804A, CN116353264A, CN117533067A, and CN221794921U all demonstrate amphibious robots that combine multi-rotor UAVs and mobile robots. However, in practice, it has been found that because these amphibious robots carry land-based components, their empty weight increases significantly. This leads to increased energy consumption, and when the amphibious robot needs to switch from vertical to horizontal flight or vice versa, the inertia of the land-based components during the transition process causes a significant decrease in the stability of the amphibious robot in the air. Therefore, a new technical solution is needed to solve the above-mentioned technical problems. Summary of the Invention

[0004] Therefore, the present invention provides an amphibious robot to solve the above-mentioned technical problems.

[0005] An amphibious robot, comprising,

[0006] Mainframe rack;

[0007] The flight component, located above the main frame, includes multiple rotor assemblies, used to enable the amphibious robot to be in vertical or horizontal flight mode.

[0008] The land-moving component, located below the main frame, includes a pair of drive components, each drive component including a land-moving device for enabling the amphibious robot to move on the ground and a linkage assembly for adjusting the position of the land-moving device.

[0009] The amphibious robot includes a first center of mass, and the land-walking device includes a second center of mass. The first center of mass and a pair of the second centers of mass define a virtual plane. When the amphibious robot is in vertical or horizontal flight, the linkage assembly adjusts the position of the land-walking device so that the virtual plane is approximately vertical.

[0010] The amphibious robot is configured such that when the flight state changes, the linkage assembly adjusts the position of the land-walking device so that the second center of mass changes accordingly.

[0011] When the second center of mass changes, the direction of motion of the second center of mass is opposite to the direction of motion of the amphibious robot's body.

[0012] The linkage assembly includes a first drive motor, a second drive motor, a first upper linkage connected to the first drive motor, a first lower linkage pivotally connected to the first upper linkage, a second upper linkage connected to the second drive motor, and a second lower linkage pivotally connected to the second upper linkage. The land-moving device is pivotally connected to the end of the first lower linkage and the end of the second lower linkage. The first drive motor and the second drive motor are mounted on a side support. The side support, the first upper linkage, the first lower linkage, the second upper linkage, and the second lower linkage form a five-bar linkage structure.

[0013] The amphibious robot also includes a control device to determine the position of the second center of mass. The control device includes an angle sensor disposed between the first upper link and the first lower link, and between the second upper link and the second lower link.

[0014] The angle sensor includes a housing and a sensor array. The sensor array includes a base and several sensor groups. The several sensor groups are equidistantly arranged on the outer side of the base along its circumference. Each sensor group includes a pair of spaced sensors, and the length ratio between each pair of sensors in the several sensor groups is different.

[0015] The angle sensor further includes a slider fixed on the housing. The slider includes contacts corresponding to a pair of sensors, through which the parameters of the corresponding sensors are obtained.

[0016] The slider includes a first electrode and a second electrode, wherein the first electrode and the second electrode respectively form contact points corresponding to a pair of sensors. Both the first electrode and the second electrode are strip-shaped and protrude from the slider toward the sensor.

[0017] In this arrangement, the lengths of the first electrodes in several sensor groups form an arithmetic sequence and increase sequentially, while the lengths of the second electrodes in several sensor groups form an arithmetic sequence and decrease sequentially.

[0018] The amphibious robot also includes a support assembly, which includes a pair of support devices. Each support device includes a leg that extends obliquely downward from a self-driven component. Each leg includes a fixed end that is fixed to a drive motor.

[0019] Beneficial Effects: This invention provides an amphibious robot, comprising: a main frame; a flight assembly disposed above the main frame, including multiple rotor assemblies for enabling the amphibious robot to be in vertical or horizontal flight; and a land-walking assembly disposed below the main frame, including a pair of drive assemblies, each drive assembly including a land-walking device for enabling the amphibious robot to move on the ground and a linkage assembly for adjusting the position of the land-walking device; the amphibious robot includes a first center of mass, and the land-walking device includes a second center of mass, the first center of mass and the pair of second centers of mass defining a virtual plane, and when the amphibious robot is in vertical or horizontal flight, the linkage assembly adjusts the position of the land-walking device so that the virtual plane is approximately vertical. This configuration enables the amphibious robot to maintain stability under different attitudes or during attitude changes, while also reducing energy consumption. Attached Figure Description

[0020] Figure 1 A three-dimensional schematic diagram of the amphibious robot according to an embodiment of the present invention;

[0021] Figure 2 for Figure 1 Middle front view;

[0022] Figure 3 for Figure 1 Middle right view;

[0023] Figure 4 This is a schematic diagram of an angle sensor;

[0024] Figure 5 This is a schematic diagram of the sensor array and slider structure;

[0025] Figure 6 for Figure 5 Enlarged diagram of area A in the middle;

[0026] Figure 7 A schematic diagram of an amphibious robot in level flight mode;

[0027] Flight component 10; main frame 100; flight motor 11; propeller blade 12; land-moving component 20; left drive component 201; right drive component 202; side support 21; first drive motor 211; second drive motor 212; first upper link 22; first lower link 23; second upper link 24; second lower link 25; land-moving device 26; land-moving motor 261; land-moving wheel 262; support device 27; outrigger 271; auxiliary wheel 272; angle sensor 28; housing 281; sensor array 282; sensor group 2820; first sensor 2821; second sensor 2822; slider 283; first electrode 2831; second electrode 2832; first center of mass 301; second center of mass 302; virtual plane 303. Detailed Implementation

[0028] Please refer to the attached document. Figure 1-3 This invention provides an amphibious robot, including a main frame 100 and a flight component 10 and a land-walking component 20 mounted on the main frame 100.

[0029] The flight component 10 is disposed above the main frame 100 and includes multiple rotor components, which enable the amphibious robot to be in flight. More specifically, the flight component 10 enables the amphibious robot to fly vertically or horizontally, thus enabling the amphibious robot to be in vertical or horizontal flight. Of course, the amphibious robot can also be in other flight states, such as oblique or spiral flight states, but the amphibious robot should at least have a vertical or horizontal flight state.

[0030] In this embodiment, there are four rotor assemblies, forming a quadcopter configuration. It is understood that the rotor assemblies are not limited to four; other suitable numbers, such as six or eight, are also feasible. Each rotor assembly includes a flight motor 11 and a blade 12 connected to the flight motor 11.

[0031] It is understood that the flight component 10 may also include a battery and a control system, which may include an electronic speed controller and a control chip, etc., which will not be described in detail here.

[0032] The land-riding component 20 is disposed below the main frame 100 and includes a pair of drive components. Specifically, the pair of drive components includes a left drive component 201 located on the left and a right drive component 202 located on the right. The left drive component 201 and the right drive component 202 have the same structure and are symmetrically arranged. The left drive component 201 will be described in detail below, while the right drive component 202 will not be described in detail.

[0033] In this embodiment, the left drive assembly 201 includes a land-walking device 26 for enabling the amphibious robot to move on the ground and a linkage assembly for adjusting the position of the land-walking device 26. The land-walking device 26 includes a land-walking wheel 262 and a land-walking motor 261 for driving the land-walking wheel 262 to rotate. In addition, in this embodiment, the land-walking motor 261 and the land-walking wheel 262 are coaxially arranged so that the land-walking wheel 262 is directly driven to move by the land-walking motor 261.

[0034] Furthermore, the main frame 100 is flat, and a pair of side supports 21 are provided on both sides of the main frame 100. The side supports 21 extend vertically downward from both sides of the main frame, so that the main frame 100 and the side supports 21 form an inverted U-shape, which together form a hollow space. The left drive component 201 and the right drive component 202 are respectively fixed on the pair of side supports 21. At the same time, a functional unit is provided in the hollow space. The functional unit may include an image acquisition unit, a control unit, etc., which will not be described in detail here.

[0035] The linkage assembly includes a first drive motor 211, a second drive motor 212, and a first upper link 22 connected to the first drive motor 21, a first lower link 23 pivotally connected to the first upper link 22, a second upper link 24 connected to the second drive motor 212, and a second lower link 25 pivotally connected to the second upper link 24. The land-moving device 26 is pivotally connected to the end of the first lower link 23 and the end of the second lower link 25. It can be understood that in this embodiment, the side support 21, the first upper link 22, the first lower link 23, the second upper link 24, and the second lower link 25 form a five-bar linkage structure. Driven by the first drive motor 211 and the second drive motor 212, the land-moving device 26 is positioned in different locations. Figure 2 In the indicated position, when the first drive motor 211 rotates counterclockwise and the second drive motor 212 rotates clockwise, and the rotation speeds of the first drive motor 211 and the second drive motor 212 are equal, the land-walking device 26 moves downward, thus extending downward. When the first drive motor 211 rotates clockwise and the second drive motor 212 rotates counterclockwise, and the rotation speeds of the first drive motor 211 and the second drive motor 212 are equal, the land-walking device 26 moves upward, thus retracting upward. It can be understood that by positioning the land-walking device 26 in different vertical positions, the amphibious robot can adapt to different motion patterns. For example, during flight, the land-walking device 26 can move upward to reduce the windward area and decrease flight resistance.

[0036] The amphibious robot includes a first center of mass 301, and the land-walking device 26 includes a second center of mass 302. The first center of mass 301 and a pair of second centers of mass 302 define a virtual plane 303, and when the amphibious robot is in vertical flight or horizontal flight, the virtual plane 303 is approximately vertical.

[0037] For more details, please refer to the following: Figure 7 ,exist Figure 7 The diagram illustrates the amphibious robot in horizontal flight. In this horizontal flight state, the amphibious robot needs to be tilted so that the thrust generated by the flight component 10 has a vertically downward component and a horizontal component. This allows the amphibious robot to overcome gravity and fly in a predetermined direction. Simultaneously, in this posture, the land-walking device 26, located below the first center of mass 301, has a restoring torque under gravity, requiring the amphibious robot to generate more thrust to maintain its tilted posture. In this situation, the aligning torque of the land-walking device 26 affects the stability of horizontal flight and increases flight energy consumption. When the first center of mass 301 and the pair of second centers of mass 302 define a virtual plane 303, and the virtual plane 303 is approximately vertical, the aligning torque generated by the land-walking device 26 is 0, thereby enabling the amphibious robot to fly more smoothly and reduce energy consumption. The approximately vertical state means that the angle between the virtual plane 303 and the vertical plane in the vertical direction is -5° to 5°.

[0038] Understandably, when the amphibious robot is in vertical flight, the virtual plane 303 should also be roughly vertical.

[0039] Understandably, the amphibious robot is configured such that when the flight state changes, the second center of mass 302 changes accordingly, and the virtual plane 303 defined by the first center of mass 301 and the pair of second centers of mass 302 remains approximately perpendicular. Specifically, the rotation of the first drive motor 211 and the second drive motor 212 can cause the first upper link 22, the first lower link 23, the second upper link 24, and the second lower link 25 to move, thereby changing the position of the land-walking device 26 located at the ends of the first lower link 23 and the second lower link 25, thus adjusting the second... In one specific embodiment, when the amphibious robot changes from a vertical flight state to a horizontal flight state, the amphibious robot needs to rotate clockwise in the vertical direction to tilt. During this process, the first drive motor 211 and the second drive motor 212 both rotate counterclockwise, thereby causing the position of the land-walking device 26 to rotate counterclockwise and move forward, thereby causing the position of the second center of mass 302 to move forward, and keeping the virtual plane 303 defined by the first center of mass 301 and the pair of second centers of mass 302 in a roughly perpendicular state.

[0040] Further research revealed that when the amphibious robot is configured such that the second center of mass 302 changes with the flight state, while the first center of mass 301 remains approximately perpendicular to the virtual plane 303 defined by the pair of second centers of mass 302, the stability of the amphibious robot during attitude changes can be further improved. Furthermore, when the second center of mass 302 changes, its direction of motion should be opposite to the direction of motion of the amphibious robot's fuselage. More specifically, when the amphibious robot changes from vertical to horizontal flight, its fuselage needs to rotate clockwise in the vertical direction to tilt. During this process, the stability of the amphibious robot during attitude changes can be further improved. Amphibious robots have a clockwise moment of inertia, which typically causes them to oscillate vertically or further correct their attitude. When the second center of mass 302 rotates counterclockwise, it directly balances the moment of inertia during attitude changes, ensuring stability. Similarly, when the amphibious robot changes from horizontal to vertical flight, the second center of mass 302 changes accordingly, keeping the first center of mass 301 and the virtual plane 303 defined by the second center of mass 302 approximately vertical, thus balancing the moment of inertia during attitude changes and maintaining stability.

[0041] Understandably, the position of the first center of mass 301 of the amphibious robot is defined by the shape and weight of the amphibious robot. When the position of the second center of mass 302 changes with the flight state, the position of the second center of mass 302 should be controlled more precisely. In this embodiment, the amphibious robot also includes a control device to determine the position of the second center of mass 302. The control device includes an angle sensor 28 disposed between the first upper link 22 and the first lower link 23. Understandably, an angle sensor is also disposed between the second upper link 24 and the second lower link 25. The first angle information between the first upper link 22 and the first lower link 23 is obtained through the angle sensor 28, and the second angle information between the second upper link 24 and the second lower link 25 is obtained through another angle sensor, thereby determining the position of the land-walking device 26 and the second center of mass 302.

[0042] Please refer to this as well. Figures 4 to 6 ,exist Figures 4 to 6 The structure of angle sensor 28 is shown in the figure. The angle sensor 28 is a triboelectric sensor. A triboelectric sensor (TENG) is a sensor based on the triboelectric effect. The triboelectric effect refers to the phenomenon that when two different materials come into contact and separate, static charges are generated at the interface due to the difference in electronegativity of the materials. When these materials move relative to each other, the charges are transferred to the electrodes, thereby generating an electrical signal. The triboelectric sensor generates charge transfer by rubbing electrode layers made of different materials together, thereby realizing the detection of displacement, pressure, rotation, etc.

[0043] The angle sensor 28 includes a housing 281 and a sensor array 282. The housing 281 is cylindrical and includes a cylindrical accommodating space. The sensor array 282 is disposed within the accommodating space and is coaxially arranged with the accommodating space. The housing is fixedly connected to the first lower connecting rod 23, and the sensor array 282 is fixedly connected to the first upper connecting rod 22. When the first lower connecting rod 23 and the first upper connecting rod 22 rotate relative to each other, the housing and the sensor array 282 rotate synchronously relative to each other.

[0044] Specifically, the sensor array 282 includes a substrate and a plurality of sensor groups 2820. The plurality of sensor groups 2820 are equidistantly arranged circumferentially on the outer surface of the substrate. Each sensor group 2820 includes a first patch 2821 and a second patch 2822, which serve as negative electrode materials in the triboelectric effect. The first patch 2821 and the second patch 2822 are spaced apart. Furthermore, the length ratio of the first patch 2821 to the second patch 2822 is different in each sensor group 2820 within the sensor array 282. When the first patch 2821... When the first patch 2821 and the second patch 2822 are triboelectrically charged, the voltage ratio formed by the first patch 2821 and the second patch 2822 is different, so that the voltage ratio of each sensor group 2820 is unique. At the same time, the angle sensor 280 also includes a slider 283 fixed on the housing 281. The slider 283 includes a pair of positive contacts that contact the first patch 2821 and the second patch 2822. When the housing and the sensor array 282 rotate relative to each other, a triboelectric effect is formed between the positive contacts and the pair of positive contacts.

[0045] Furthermore, the slider 283 includes a first electrode 2831 and a second electrode 2832. The first electrode 2831 abuts against the first patch 2821, and the second electrode 2832 abuts against the second patch 2822. Both the first electrode 2831 and the second electrode 2832 are strip-shaped and protrude from the slider 283 toward the sensor array 282.

[0046] Furthermore, the lengths of the first patches 2821 in the plurality of sensor groups 2820 are arranged in an arithmetic sequence and increase sequentially. At the same time, the lengths of the second patches 2822 in the plurality of sensor groups 2820 are arranged in an arithmetic sequence and decrease sequentially. In a specific embodiment, the lengths of the first patches 2821 are 1mm, 2mm, 3mm...16mm, while the lengths of the second patches 2822 are 16mm, 15mm, 14mm...1mm, so that the voltage ratios in each sensor group 2820 are 1 / 16, 2 / 15, 3 / 14...16 / 1, respectively. By detecting the voltage ratio, the specific position of the slider 283 in the sensor array 282 can be obtained, thereby determining the angle between the sensor array 282 and the housing.

[0047] Furthermore, in order to enhance the triboelectric effect, the surfaces of the first patch 2821 and the second patch 2822 include etched microtextures to increase the contact area and improve the charge separation effect.

[0048] Furthermore, an elastic support can be included between the first electrode 2831, the second electrode 2832 and the slider 283. Under the elastic force of the elastic support, the first electrode 2831 and the second electrode 2832 can maintain stable contact during the sliding process and sense the charge transfer signal.

[0049] Furthermore, both the first patch 2821 and the second patch 2822 are polytetrafluoroethylene sheets, and both the first electrode 2831 and the second electrode 2832 are copper electrodes.

[0050] Furthermore, the surfaces of the first patch 2821 and the second patch 2822 are covered with a polyimide film to ensure the durability and resistance to environmental interference of the sensor, as well as to protect the sensitive material from moisture and contaminants. It is understood that the polyimide film can be attached using hot pressing or UV curing processes.

[0051] Furthermore, the amphibious robot also includes a support assembly configured to support the amphibious robot together with the land-walking device 26, so as to maintain a stable state when the amphibious robot stops flying or moving. The support assembly includes a pair of support devices 27, each of which includes a leg 271 that extends obliquely downward from a self-driven component. The legs 271 of the pair of support devices 27 extend in opposite directions. Specifically, when one leg 271 extends to the lower left, the other leg 271 extends to the lower right. At the same time, the pair of legs 271 and the pair of land-walking wheels 262 provide support for the amphibious robot.

[0052] Furthermore, the support device 27 also includes auxiliary wheels 272 located at the ends of the outriggers 271, which can cushion the landing of the amphibious robot and assist the amphibious robot in moving on land.

[0053] Furthermore, the outrigger 271 includes a fixed end, which is fixed to the drive motor. More specifically, the fixed end of one leg 271 is fixed to the first drive motor 211, and the fixed end of the other leg 271 is fixed to the second drive motor 212. This structure can provide more stable support for the amphibious robot.

[0054] Furthermore, the linkage assembly is controlled via a VMC control algorithm to adjust the position of the land-moving device. Specifically, virtual model control (VMC) is used to generate virtual forces and virtual torques using a spring-damping assembly. The virtual force is calculated using the following formula:

[0055] F y =k y (Δh)+d y y

[0056] The virtual torque is calculated using the following formula:

[0057] Tx=k θ (Δθ) + d y θ

[0058] Then, Simulink simulation was used to optimize the elastic coefficient. , and damping coefficient , .

[0059] In addition, for nonlinear cases where the center of gravity height changes due to the adjustment of the land vehicle position by the linkage assembly, an interval interpolation method is used to divide the center of gravity height into three intervals. Different LQR feedback parameters are used in different intervals, while the same parameters are used in the same interval, ensuring that the robot can achieve good control performance at all heights.

[0060] Furthermore, the motion of the land-riding device is controlled using the LQR control algorithm. Specifically, a state-space model is designed: the robot's wheeled motion is modeled as a two-wheeled inverted pendulum, and its state-space expression is obtained through linearized dynamic equations. A controller based on the LQR control algorithm is designed: by configuring the feedback matrix... Introduce the cost function:

[0061]

[0062] Optimize system performance.

[0063] Then, Simulink simulation was performed to adjust the feedback matrix parameters. To verify the stability and performance of the control system.

[0064] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. An amphibious robot, characterized in that, The amphibious robot comprises a main frame, a flight assembly arranged above the main frame, a land travel assembly arranged below the main frame, and a control device. The flight assembly comprises a plurality of rotor assemblies for enabling the amphibious robot to be in a vertical flight state or a horizontal flight state. The land travel assembly comprises a pair of drive assemblies, each of which comprises a land travel device for enabling the amphibious robot to travel on the ground and a linkage assembly for adjusting the position of the land travel device. The amphibious robot comprises a first center of mass, the land travel device comprises a second center of mass, the first center of mass and the pair of second centers of mass define a virtual plane, and when the amphibious robot is in the vertical flight state or the horizontal flight state, the linkage assembly adjusts the position of the land travel device so that the virtual plane is substantially vertical. The linkage assembly comprises a first drive motor, a second drive motor, a first upper linkage connected to the first drive motor, a first lower linkage pivotally connected to the first upper linkage, a second upper linkage connected to the second drive motor, and a second lower linkage pivotally connected to the second upper linkage. The amphibious robot further comprises a control device for determining the position of the second center of mass, the control device comprises an angle sensor arranged between the first upper linkage and the first lower linkage and between the second upper linkage and the second lower linkage, and the angle sensor is a triboelectric sensor. The angle sensor comprises a sleeve shell and a sensor array, the sensor array comprises a base body and a plurality of sensor groups, the plurality of sensor groups are arranged equidistantly along the circumferential direction of the outer side of the base body, each sensor group comprises a first patch and a second patch, the first patch and the second patch are arranged at intervals, and the length ratio of the first patch to the second patch in each sensor group of the sensor array is different. The angle sensor further comprises a slide fixed on the sleeve shell, the slide comprises a first electrode and a second electrode, when the sleeve shell rotates, the first electrode can abut against the first patch, and the second electrode can abut against the second patch, the first electrode and the second electrode are in strip shapes and protrude from the slide to the sensor array. When the flight state changes, the linkage assembly adjusts the position of the land travel device so that the second center of mass changes accordingly.

2. The amphibious robot of claim 1, wherein, When the second center of mass changes accordingly, the movement direction of the second center of mass is opposite to the movement direction of the body of the amphibious robot.

3. The amphibious robot of claim 2, wherein, The land travel device is pivotally connected to the end of the first lower linkage and the end of the second lower linkage, the first drive motor and the second drive motor are arranged on a side bracket, and the side bracket, the first upper linkage, the first lower linkage, the second upper linkage, and the second lower linkage form a five-link structure.

4. The amphibious robot of claim 3, wherein, The lengths of the first patches in the plurality of sensor groups form an arithmetic sequence and increase in turn, and the lengths of the second patches in the plurality of sensor groups form an arithmetic sequence and decrease in turn.

5. The amphibious robot of claim 4, wherein, The amphibious robot further comprises a support assembly, the support assembly comprises a pair of support devices, each support device comprises a support leg extending obliquely downward from a drive assembly, and the support leg comprises a fixed end fixed on the drive motor.

6. The amphibious robot of claim 3, wherein, ​ 7. The amphibious robot of claim 1, wherein, The linkage assembly adjusts the position of the land vehicle through a VMC control algorithm.

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