Bistable propeller driving device, propeller and robot

Abstract

The invention discloses a bistable thruster driving device, a thruster and a robot, and relates to the technical field of miniature underwater drive.The bistable thruster driving device comprises a driving device and a bistable membrane, and the bistable membrane has the two balance states of the convex state and the concave state; a power cavity is defined by the bistable membrane and the side wall of a part of the cavity of the propeller body, the power cavity communicates with the inflow channel and the outflow channel, the driving device is used for enabling the bistable membrane to be switched between the protruding state and the sunken state, and the bistable membrane is switched from the sunken state to the protruding state so that the inflow channel can generate negative pressure to absorb external fluid; when the bistable membrane is switched from the convex state to the concave state, the outflow channel can generate positive pressure to discharge fluid to the outside, and the propeller body is made to move; the thruster comprises a thruster body and the bistable thruster driving device. The robot comprises a robot body and the propeller. The propeller is driven to move under relatively non-high pressure, and the failure phenomenon is not prone to occurring.

Description

Technical Field

[0001] This invention relates to the field of micro underwater propulsion technology, and in particular to a bistable thruster drive device, a thruster, and a robot. Background Technology

[0002] In complex underwater environments, underwater robots require propulsion for movement. Existing propulsion systems consist of a shell, a blocking layer, and a vibrating layer. The shell has input and output channels. The middle of the vibrating layer connects to the blocking layer, which blocks the input channel. The vibrating layer, blocking layer, and shell form a pressure-changing chamber. The vibrating layer deforms under the influence of an alternating magnetic field. When the vibrating layer receives a signal, its middle section moves upward, separating the blocking layer from the input channel. Simultaneously, the edges of the vibrating layer move downward and press against the shell. This deformation increases the volume of the pressure-changing chamber, connecting it to the input channel while isolating it from the output channel. External fluid is drawn into the input channel and pressure-changing chamber. The fluid in the output channel is forced out through the nozzle, generating propulsion. When the vibrating layer receives another signal, the middle part of the vibrating layer moves downward, blocking the input flow channel. Simultaneously, the edges of the vibrating layer move upward, separating from the shell. This deformation of the vibrating layer reduces the volume of the transformer chamber, connecting it to the output flow channel while isolating it from the input flow channel. Fluid in the transformer chamber then flows into the output flow channel. Therefore, by inputting a periodic alternating voltage to the vibrating layer, fluid can be transported within the cavity, continuously generating a backward propulsive force at the nozzle, thus driving the underwater robot. Currently, vibrating layers are mostly composed of a piezoelectric sheet and a substrate composite. The materials themselves are relatively hard, not easily bent, require a high-pressure environment, and are prone to failure. Summary of the Invention

[0003] The purpose of this invention is to provide a bistable thruster drive device, thruster, and robot to solve the problems existing in the prior art, enabling the thruster to be driven in a less high-pressure driving environment and reducing the likelihood of failure.

[0004] To achieve the above objectives, the present invention provides the following solution: This invention provides a bistable thruster drive device, comprising a drive unit and a bistable diaphragm. The bistable diaphragm has two equilibrium states: a convex state and a concave state. The bistable diaphragm and a portion of the sidewall of the thruster body enclose a power cavity, which is connected to both the inflow channel and the outflow channel of the thruster body. The drive unit is used to switch the bistable diaphragm between the convex and concave states. When the bistable diaphragm switches from the concave to the convex state, it generates a negative pressure in the inflow channel to absorb external fluid. When the bistable diaphragm switches from the convex to the concave state, it generates a positive pressure in the outflow channel to discharge fluid to the outside and move the thruster body.

[0005] In one embodiment, the bistable membrane is a flexible membrane with magnetic properties, and the driving device is capable of generating a magnetic field with changing direction. The change in the direction of the magnetic field of the driving device can enable the bistable membrane to switch between the convex state and the concave state.

[0006] In one embodiment, the bistable membrane is perpendicular to the axis of the power cavity.

[0007] In one embodiment, the magnetic field frequency of the driving device is changed to cause the bistable membrane to switch between the convex state and the concave state at varying speeds.

[0008] In one embodiment, the drive device includes a coil fixedly mounted on the thruster body, the axis of the coil coinciding with the axis of the power chamber.

[0009] In one embodiment, the bistable membrane is a flexible membrane made of hard magnetic material.

[0010] The present invention also provides a thruster, including a thruster body and the above-described bistable thruster drive device.

[0011] In one embodiment, the inflow channel is a one-way inflow channel to allow the fluid to flow in one direction, and the outflow channel is a one-way outflow channel to allow the fluid to flow out one direction.

[0012] In one embodiment, both the inflow channel and the outflow channel have Tesla valves.

[0013] The present invention also provides a robot, including a robot body and the aforementioned thruster.

[0014] The present invention achieves the following technical effects compared to the prior art: This invention discloses a bistable thruster drive device. The bistable membrane itself has two stable equilibrium states, and it can undergo rapid and large-scale flipping deformation under external disturbances, while remaining stable without external excitation. The bistable membrane is configured to have a convex state and a concave state. Therefore, the bistable membrane only requires a small driving force to switch between the convex and concave states. Switching from the concave state to the convex state can generate negative pressure in the inflow channel to absorb external fluid, and switching from the convex state to the concave state can generate positive pressure in the outflow channel to discharge fluid to the outside and move the thruster body. Using the bistable membrane in the thruster body to realize pressure conversion inside the power chamber is beneficial to improving the thruster's working efficiency and stability and avoiding thruster failure. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of one embodiment of the bistable thruster drive device in Example 1; Figure 2 This is a schematic diagram of the protruding state in the thruster of Embodiment 2; Figure 3 This is a schematic diagram of the recessed state in the thruster of Embodiment 2; Figure 4 This is a cross-sectional view of the inflow channel in the thruster of Embodiment 2; Figure 5 This is a cross-sectional view of the outflow channel in the propeller of Embodiment 2; In the diagram: 1. Drive unit; 2. Bistable membrane; 3. Thruster body; 4. Inflow channel; 5. Outflow channel; 6. Power chamber. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] The purpose of this invention is to provide a bistable thruster drive device, thruster, and robot to solve the problems existing in the prior art, enabling the thruster to be driven in a less high-pressure driving environment and reducing the likelihood of failure.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Example 1 This embodiment provides a bistable thruster drive device, including a drive device 1 and a bistable diaphragm 2. The bistable diaphragm 2 has two equilibrium states: a convex state and a concave state. The bistable diaphragm 2 and a portion of the chamber sidewall of the thruster body 3 enclose a power chamber 6. The power chamber 6 is connected to both the inflow channel 4 and the outflow channel 5 of the thruster body 3. The drive device 1 is used to switch the bistable diaphragm 2 between the convex and concave states. When the bistable diaphragm 2 switches from the concave state to the convex state, it can generate a negative pressure in the inflow channel 4 to absorb external fluid. When the bistable diaphragm 2 switches from the convex state to the concave state, it can generate a positive pressure in the outflow channel 5 to discharge fluid to the outside and make the thruster body 3 move.

[0021] The bistable membrane 2 itself has two stable equilibrium states, and the bistable membrane 2 can undergo rapid and large-scale flipping deformation under external disturbances and remain stable without external excitation. In this embodiment, the bistable membrane 2 is configured to have a convex state and a concave state. Therefore, the bistable membrane 2 only requires a small driving force to switch between the convex state and the concave state. Switching from the concave state to the convex state can generate negative pressure in the inflow channel 4 to absorb external fluid. Switching from the convex state to the concave state can generate positive pressure in the outflow channel 5 to discharge fluid to the outside and make the thruster body 3 move. Using the bistable membrane 2 in the thruster body 3 to realize the pressure conversion inside the power chamber 6 is beneficial to improving the working efficiency and stability of the thruster and avoiding thruster failure.

[0022] In one embodiment, the bistable membrane 2 is a flexible membrane with magnetism, and the driving device 1 can generate a magnetic field with changing direction. The change in the direction of the magnetic field of the driving device 1 can switch the bistable membrane 2 between a convex state and a concave state.

[0023] The bistable membrane 2 is driven by the magnetic field of the drive device 1. There is no mechanical contact, friction, or wear between the drive device 1 and the bistable membrane 2, which significantly improves the service life of the bistable membrane 2 and thus extends the service life of the thruster. When the direction of the magnetic field of the drive device 1 is the same as the direction of the magnetic field on the upper surface of the bistable membrane 2, the bistable membrane 2 switches from a convex state to a concave state. Conversely, when the direction of the magnetic field of the drive device 1 is different from the direction of the magnetic field on the upper surface of the bistable membrane 2, the bistable membrane 2 switches from a concave state to a convex state. The change in the direction of the magnetic field of the drive device 1 can quickly and stably trigger the state jump of the bistable membrane 2, which is beneficial to improving the response efficiency of the thruster's fluid intake and exhaust.

[0024] In one embodiment, the bistable membrane 2 is perpendicular to the axis of the power cavity 6.

[0025] The bistable membrane 2 is positioned perpendicular to the axis of the power chamber 6, which makes the force within the power chamber 6 uniform, maximizes the pressure transmission efficiency, eliminates lateral force loss, and makes the fluid inflow and outflow response faster and more sensitive.

[0026] In one embodiment, the magnetic field frequency of the driving device 1 is changed to cause the bistable membrane 2 to switch between a convex state and a concave state at varying speeds.

[0027] The speed at which the bistable membrane 2 switches between a convex state and a concave state can be changed, and the size can change the degree of concavity and convexity of the membrane.

[0028] By changing the magnetic field frequency of the drive device 1, the frequency of change of the bistable diaphragm 2 can be adjusted, thereby continuously and accurately controlling its switching speed between the convex and concave states. Furthermore, by changing the magnitude of the magnetic field, the degree of change of the bistable diaphragm 2 can be changed to alter the pressure within the power chamber 6, meeting the needs of different thrusters. The structure is simple and easy to operate.

[0029] In one embodiment, the drive device 1 includes a coil, which is fixedly mounted on the thruster body 3, and the axis of the coil coincides with the axis of the power chamber 6.

[0030] The axis of the coil coincides with the axis of the power cavity 6, which enables the driving force distribution to be symmetrical and uniform when switching between the raised and recessed states along the same axis. The force on the bistable membrane 2 is consistent in direction and balanced, avoiding off-center loading and jamming, and making the state switching more stable and reliable. The coaxial setting can maximize the use of driving force, reduce losses, improve driving efficiency, and reduce energy consumption.

[0031] In one optional embodiment, the coil is a hollow solenoid with a bistable diaphragm 2 disposed in the middle. The coil is connected to a programmable AC power supply via wires, which can output current with the required frequency, amplitude, and waveform. The coil is used to pass an AC current of a specific waveform to generate an alternating magnetic field that changes periodically along the axial direction at the execution unit location. The alternating current causes a change in the direction of the coil's magnetic field, causing the bistable diaphragm 2 to experience a change in the direction of the force within the magnetic field, exciting it to form either a concave or convex stable state. When the directions of the coil's magnetic field and the bistable diaphragm 2's magnetic field are opposite, an attractive force is generated between them, causing the bistable diaphragm 2 to convex, creating a negative pressure inside the power chamber 6 of the thruster body 3, thus absorbing fluid. When the directions of the coil's magnetic field and the bistable diaphragm 2's magnetic field are the same, a repulsive force is generated between them, causing the bistable diaphragm 2 to concave, creating a positive pressure, discharging fluid outward to enable the thruster body to move the robot. This cycle of changing the pressure inside the power chamber 6 of the thruster body 3 achieves the water intake and drainage propulsion function.

[0032] The power supply employs a hybrid waveform drive, with the alternating magnetic field driving waveform being a square wave, a sine wave, or a hybrid waveform modulated for energy saving. Within one cycle, the hybrid waveform includes a peak segment above the critical reversal magnetic field to trigger state reversal, and a sustaining segment below the critical reversal magnetic field but sufficient to maintain the current stable state, thus reducing average energy consumption. By coordinating the adjustment of the alternating current frequency and amplitude, the frequency and intensity of the electromagnetic field are kept at a stable level that ensures the execution unit can reliably complete a full switch within each half-cycle. The switching speed of the bistable membrane 2 can be altered by changing the magnitude and frequency of the alternating current; a larger alternating current results in a faster switching speed, while a smaller alternating current results in a slower switching speed. Similarly, a faster alternating current frequency results in a faster switching speed, while a slower alternating current frequency results in a slower switching speed.

[0033] The coil can have one or more turns. By setting the coil to one or more turns, the number of turns can be flexibly adjusted according to the thruster's driving requirements. When a faster thruster speed is required, a coil with more turns can be selected; when a slower thruster speed is required, a coil with fewer turns can be selected.

[0034] In one embodiment, the bistable membrane 2 is a flexible membrane made of hard magnetic material.

[0035] Flexible and hard magnetic materials are selected and mixed evenly. The mixture is then cast into a dome-shaped bistable membrane 2 using a mold. After the thin film on the surface of the bistable membrane 2 is axially magnetized, each of the upper and lower surfaces presents a magnetic pole. This allows the bistable membrane 2 to have two stable equilibrium states, a convex state and a concave state, when there is no external field. It can also switch between the convex state and the concave state after the direction of the magnetic field of the driving device 1 is changed.

[0036] Flexible materials such as silicone and polydimethylsiloxane are selected, while hard magnetic materials such as neodymium iron boron and NdFeB are selected.

[0037] Example 2 This embodiment also provides a thruster, including a thruster body 3 and a bistable thruster drive device of Embodiment 1.

[0038] The bistable thruster drive unit can drive the thruster body 3 to move.

[0039] In one embodiment, the inflow channel 4 is a one-way inflow channel 4 to allow fluid to flow in one direction, and the outflow channel 5 is a one-way outflow channel 5 to allow fluid to flow out one direction.

[0040] Adding a flow channel can guide the fluid, allowing it to flow smoothly and unidirectionally into the inlet and orderly out through the outlet. This optimizes the flow path, reduces fluid resistance, avoids the impact of fluid turbulence on suction and discharge efficiency, and further improves the working efficiency of the propeller.

[0041] In one embodiment, both the inflow channel 4 and the outflow channel 5 have Tesla valves.

[0042] The inflow channel 4 and the outflow channel 5 adopt a Tesla valve structure. The arrangement of the inflow channel 4 and the outflow channel 5 can be adjusted according to the structure. It is not necessary to have an up-down structure. It can also be arranged left-right. In order to achieve multi-degree-of-freedom propulsion, the number of inflow channels 4 and outflow channels 5 can also be adjusted.

[0043] In an alternative embodiment, an inlet and an outlet can be provided on the propeller body 3. A one-way inlet valve is provided on the inlet and a one-way outlet valve is provided on the outlet to ensure that the fluid enters from the inlet and exits from the outlet, thereby avoiding the impact of fluid turbulence on the suction and drainage efficiency.

[0044] Example 3 This embodiment also provides a robot, including a robot body and a thruster as described in Embodiment 2.

[0045] The robot is equipped with thrusters, which enable it to move.

[0046] Working principle: The robot is placed in a fluid medium, and an alternating current of a preset frequency and amplitude is supplied to the drive device 1, generating an alternating magnetic field along the axial direction. When the direction of the alternating magnetic field changes from the magnetization direction inside the bistable membrane 2 and exceeds the critical reversal magnetic field, the bistable membrane 2 rapidly switches between a convex state and a concave state due to magnetic torque instability. With the periodic reversal of the direction of the alternating magnetic field, the bistable membrane 2 oscillates rapidly between the convex and concave states.

[0047] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A bistable thruster drive device, characterized in that: The device includes a drive unit and a bistable membrane. The bistable membrane has two equilibrium states: a convex state and a concave state. The bistable membrane and a portion of the sidewall of the propeller body form a power chamber. The power chamber is connected to both the inflow channel and the outflow channel of the propeller body. The drive unit is used to switch the bistable membrane between the convex state and the concave state. When the bistable membrane switches from the concave state to the convex state, it can generate negative pressure in the inflow channel to absorb external fluid. The switching of the bistable membrane from the convex state to the concave state enables the outflow channel to generate positive pressure to discharge fluid to the outside and to move the propeller body.

2. The bistable thruster drive device according to claim 1, characterized in that: The bistable membrane is a flexible membrane with magnetic properties. The driving device can generate a magnetic field with changing direction. The change in the direction of the magnetic field of the driving device can switch the bistable membrane between the convex state and the concave state.

3. The bistable thruster drive device according to claim 1, characterized in that: The bistable membrane is perpendicular to the axis of the power cavity.

4. The bistable thruster drive device according to claim 2, characterized in that: The frequency of the magnetic field of the driving device is changed to change the switching speed of the bistable membrane between the convex state and the concave state.

5. The bistable thruster drive device according to claim 2, characterized in that: The drive device includes a coil, which is fixedly mounted on the propeller body, and the axis of the coil coincides with the axis of the power chamber.

6. The bistable thruster drive device according to claim 2, characterized in that: The bistable membrane is a flexible membrane made of hard magnetic material.

7. A thruster, characterized in that: It includes the thruster body and the bistable thruster drive device as described in any one of claims 1-6.

8. The thruster according to claim 7, characterized in that: The inflow channel is a one-way inflow channel to allow the fluid to flow in one direction, and the outflow channel is a one-way outflow channel to allow the fluid to flow out one direction.

9. The thruster according to claim 7, characterized in that: Both the inflow channel and the outflow channel are equipped with Tesla valves.

10. A robot, characterized in that: Includes the robot body and the thruster as described in any one of claims 7-9.

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