CN113733832A - Aerodynamic force adsorption device for realizing flying of wall-climbing robot - Google Patents

Abstract

The invention relates to a pneumatic adsorption device for realizing the flight of a wall-climbing robot, belonging to the field of pneumatic design; the device comprises a gap limiting structure, a sucker, a motor, a propeller and a connecting seat, wherein the bottom end of the sucker is connected with a robot body through the connecting seat; the motor is coaxially arranged on the connecting seat, an output shaft of the motor is coaxially connected with the propeller, the propeller is coaxially arranged in the sucker, the radius of a pulp disk of the propeller is R, the gap limiting structure is a hemispherical protrusion arranged on the surface of a lip of the sucker and used for limiting the distance between the sucker and the wall surface, and the axial height of the gap limiting structure is 5% of the diameter of the pulp disk; the peripheral wall of the sucker is of an expansion structure from the bottom end to the lip along the axial direction; the lip is turned outwards, and the axial section of the lip is a convex arc section with the circle center positioned outside the peripheral wall of the sucker. The net adsorption force (the resultant force of thrust and negative pressure) generated by the sucker with the outwards-turned arc section lip on the near wall surface is improved by nearly 50% compared with that of a straight wall type sucker, and the generated lift force is improved by about 25% compared with that of a horizontal flying state in the air.

Description

Aerodynamic force adsorption device for realizing flying of wall-climbing robot

Technical Field

The invention belongs to the field of pneumatic design, and particularly relates to a pneumatic adsorption device for realizing the flight of a wall-climbing robot.

Background

The wall climbing robot has great research prospect in various fields, particularly dangerous work industries. Through years of research, the wall climbing robot has multiple working modes and longer working time, but the adsorption mode adopted by the wall climbing robot has poorer adaptability to different wall materials or walls with poorer flatness, and the energy consumption of the existing adsorption mode is very large, but the adsorption technology by using a novel material is still immature; and secondly, the device is gradually applied in the field of anti-terrorism reconnaissance, and compared with an anti-terrorism unmanned aerial vehicle capable of flying, the flexibility, obstacle-surmounting capability and working efficiency of the device are slightly inferior, so that a special adsorption device is designed, the wall climbing robot is endowed with stronger wall adaptive capacity and flexible flying capability, and the device has very important significance.

At present, the adsorption modes of the wall-climbing robot generally include a magnetic adsorption mode, a vacuum adsorption mode, a negative pressure adsorption mode, a thrust adsorption mode generated by the rotation of a propeller, an adsorption mode by using a novel special material and the like. The magnetic adsorption method has strong adaptability to the concave-convex degree of the wall surface and larger adsorption force, but the principle of the generation of the adsorption force requires that the wall surface is made of magnetic conductive materials, so the application environment of the adsorption method is severely limited, while the vacuum adsorption method does not greatly limit the material of the wall surface, but has higher requirement on the sealing degree, and when the wall surface is concave-convex and uneven, the suction cup attached to the wall surface is easy to leak air due to the influence of a gap, so the adsorption force is reduced. These methods do not have the condition that the robot has flight capability, and in principle, the method of propeller thrust adsorption is closest to the aircraft, but the method consumes much energy and cannot work for a long time.

In contrast, the composite adsorption device mentioned in 200810227554.X provides a solution, which utilizes a combination device of a diversion duct, a negative pressure cavity and wheels, and ensures that the negative pressure cavity can still realize stable adsorption with small power under the condition of a certain gap between the negative pressure cavity and the wall surface under the comprehensive action of the reverse thrust and the negative pressure of the propeller, and the wall surface adaptability is strong. But its weight is large and stable flight of the robot cannot be achieved as well. There is therefore a need for improvements in such devices to overcome the above-mentioned disadvantages.

The existing duct has very remarkable advantages for lifting force, but the adsorption effect is weak under the adherence state, the top suction can be realized under high power by utilizing the thrust of the propeller, but the effective action area of the negative pressure on the duct is very small when the vertical wall surface adsorbs, and the adsorption effect is difficult to realize. The suction disc used by the existing wall surface mobile robot utilizing propeller thrust and negative pressure can realize wall surface adsorption with lower energy consumption and has strong adaptability to the wall surface, but the utilization rate of the lifting force performance of the propeller is not high, so that the wall surface mobile robot can not fly as easily as a common gyroplane.

Disclosure of Invention

The technical problem to be solved is as follows:

in order to avoid the defects of the prior art, the invention provides the aerodynamic adsorption device for realizing the flight of the wall-climbing robot, the wall-climbing robot is ensured to have good adsorption performance and stable flight capability by matching the specially designed suckers with the propellers, and the flexible wall surface movement is realized by matching the wheels on the two sides of the body. And the utilization rate of energy is as high as possible when each function is realized so as to improve the task duration.

The technical scheme of the invention is as follows: a aerodynamic force adsorption device for realizing the flight of a wall-climbing robot comprises a sucker, a motor, a propeller and a connecting seat, wherein the bottom end of the sucker is connected with a robot body through the connecting seat; the motor is coaxially arranged on the connecting seat, an output shaft of the motor is coaxially connected with the propeller, the propeller is coaxially arranged in the sucker, and the radius of a paddle disk of the propeller is R; the method is characterized in that: the device also comprises a gap limiting structure, wherein the gap limiting structure is a hemispherical protrusion arranged on the surface of the lip of the sucker and used for limiting the distance between the sucker and the wall surface, and the axial height H of the gap limiting structure is 5% of the diameter of the pulp disk;

the peripheral wall of the sucker is of an expansion structure from the bottom end to the lip opening along the axial direction; the lip is turned outwards, and the axial section of the lip is a convex arc section with the circle center positioned outside the peripheral wall of the sucker.

The further technical scheme of the invention is as follows: the radius of the end face of the bottom end of the sucker is 0.996R; taking the end face of the bottom end of the sucker as a reference, wherein the axial height h of the middle point of the paddle disc is 0.6R, and the radius d of the inner wall of the sucker corresponding to the height of the paddle disc is 1.04R; the minimum clearance s between the propeller tip of the propeller and the inner wall of the suction disc is 2.33% of the diameter of the propeller disc; the axial height of the vertex of the lip of the sucking disc is 0.51 time of the diameter of the paddle disc, and the radius D/2 of the circumference where the vertex is located is 1.576R.

The further technical scheme of the invention is as follows: the radius of the convex arc of the axial section of the lip is 0.3R.

The further technical scheme of the invention is as follows: the generatrix of the circumferential wall of the sucker is formed by two sections of curves in a smooth transition mode, the first section of curve is a position with the axial height of 0.974R from the bottom end face of the sucker to the circumferential wall of the sucker, and the radius of the inner wall of the sucker is 1.34R; the second section of curve is a convex arc section with the outward-turned lip.

The further technical scheme of the invention is as follows: the gap defining structure is a bull-eye bearing.

The further technical scheme of the invention is as follows: the connecting base comprises a motor base and a sucker mounting base, and the motor base is positioned in the center; the sucking disc installation base is semicircle ring structure, and its inner peripheral face is fixed in motor base's periphery through 3 ordinary ribs coaxial that set up along circumference.

The further technical scheme of the invention is as follows: and reinforcing ribs are also arranged between the motor base and the sucker mounting base.

The further technical scheme of the invention is as follows: the diameter of the motor base is 0.57R, and the diameter of the disk mounting base is 0.998R.

The further technical scheme of the invention is as follows: the bottom end circumference of the sucker is provided with mortises which correspond to the positions of the ribs on the connecting seat one by one and are matched with each other for installation, so that the sucker and the connecting seat are fixed.

The further technical scheme of the invention is as follows: the axial height of the mortise is 0.09R.

Advantageous effects

The invention has the beneficial effects that: when a rigid non-deformable gap limiting structure is contacted with the wall surface, a fixed narrow gap (namely 5% of the diameter of a pulp disk) is kept between the lip plane of the suction disk and the wall surface, the propeller rotates to generate negative pressure in the suction disk of the duct-like channel, and the pressure is transmitted to the wheels of the machine body through the connecting seat under the combined action of the thrust of the propeller which is smaller than the pressure, wherein the wheels are the mechanism for limiting the movement of the machine body and the maximum gap and are the most main source of friction force, so that the wall surface attachment is realized. Compared with the technical scheme of the patent 200810227554.X applying negative pressure adsorption, the lip section in the invention is an outward turning convex arc section instead of a straight wall section, and theoretical calculation and experimental verification results show that the net adsorption force (the resultant force of thrust and negative pressure) generated by the sucker applying the outward turning arc section lip on the near wall surface is improved by nearly 50% compared with a straight wall type, and the generated lift force is improved by about 25% compared with a lift force in a horizontal flight state in the air. In addition, the suction force provided by the suction cup and the lifting force during the flat flying process are increased along with the increase of the radius of the lip eversion section, when the radius exceeds 0.3R, the increase of the suction force tends to be gentle, and the lifting force begins to be reduced.

Due to different moving mechanisms, compared with the gap limiting device mentioned in the patent 200810227554.X, the gap limiting structure in the invention is only a hemispherical small protrusion on the lip of the sucking disc, and under the condition that a plurality of sucking discs act together in practical application, the plane of the lip of the sucking disc and the wall surface can be stabilized at a fixed distance. The protrusions are point-contact with the wall surface, and the friction-inhibiting effect generated during movement is negligible. Through the study on the radius of the projection, the magnitude of the adsorption force is found to increase with the decrease of the radius thereof until 10% R, and then the adsorption force is reduced instead. Experiments also verify that the adsorption force is proportionally maximum when the gap is limited to 10% R.

In addition, under the interaction of the suction cup inner duct and the propeller, the tip vortex of the propeller is formed at the tip of the propeller due to the pressure difference between the pressure surface and the playing surface, and the loss is caused to the pneumatic efficiency of the propeller, so compared with the scheme provided in 200810227554.X, the invention also researches the gap between the tip of the propeller and the inner wall of the suction cup for further improving the efficiency of the propeller. After simulation calculation and experiments, it is found that for the suction cup propeller combination system in the present invention, reducing the clearance between the blade tip and the inner wall is an effective means for improving the aerodynamic efficiency, when the clearance is smaller than 7.5% of the propeller radius, the blade space is more excellent in both the lift force and the adsorption force, and the aerodynamic performance is smoothly improved along with the reduction of the clearance, but in practical tests, it is found that when the clearance is smaller than 2.33% of the diameter of the propeller disc, the problems of beating and the like easily occur due to the deformation of the blade.

The experimental conclusion shows that when the lip eversion radius is 0.3R, the gap limits the structure radius to 10% R, and under the clearance condition of 2.33% of the diameter of a pulp disk, the robot provided with four pneumatic adsorption devices and a set of two-wheel differential movement device in the specific embodiment can realize stable vertical wall adsorption by less than 10% of the throttle, realize flexible wall movement by 15% of the throttle, and can stably fly only by about 40% of the throttle during air level flight. In addition, the power consumed during air flight is about 600 watts, the power consumed during wall surface adsorption is about 40 watts, the power consumed during wall surface adsorption is only 1/15 of the air flight process, and the working time is greatly prolonged.

Drawings

FIG. 1 is a front view of the aerodynamic suction device of the present invention.

Fig. 2 is a schematic view of the assembly of the suction cup and the connecting seat of the aerodynamic suction device of the present invention.

Fig. 3 is an axial view of the inner wall surface of the suction pad of the aerodynamic suction device of the present invention.

Description of reference numerals: 1. the gap is limited structure, 2, the semicircular arc section lip of evagination, 3, the mortise, 4, the connecting seat.

Detailed Description

The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

The invention relates to an aerodynamic force adsorption device for realizing the flight of a wall-climbing robot, which is shown in figure 1 and comprises a gap limiting structure 1, a sucker 2, a motor, a propeller and a connecting seat 4, wherein the bottom end of the sucker 2 is connected with a robot body through the connecting seat 4; the motor is coaxially arranged on the connecting seat 4, the output shaft of the motor is coaxially connected with the propeller, the propeller is coaxially arranged in the sucking disc, and the radius of the propeller disc of the propeller is R; the gap limiting structure 1 is a hemispherical protrusion arranged on the surface of the lip of the sucker 2 and used for limiting the distance between the sucker 2 and the wall surface, and the axial height H of the gap limiting structure is 5% of the diameter of the pulp disk;

referring to fig. 2 and 3, the connecting seat 4 includes a motor base and a suction cup mounting base, and the motor base is located at the center; the sucking disc installation base is a semicircular structure and is used for realizing weight reduction, and the inner peripheral surface of the sucking disc installation base is coaxially fixed on the periphery of the motor base through 3 common ribs and 1 reinforcing rib which are arranged along the circumferential direction. Be provided with the mortise on 2 bottom global of sucking disc, with the position one-to-one of the ordinary rib on connecting seat 4 and stiffening rib to mutually support the installation, realize sucking disc 2 and connecting seat 4 fixed, the axial height of mortise is 0.09R. The diameter of the motor base is 0.57R, and the diameter of the disk mounting base is 0.998R.

The peripheral wall of the sucker is of an expansion structure from the bottom end to the lip opening along the axial direction; the lip is turned outwards, the axial section of the lip is a convex arc section with the circle center positioned at the outer side of the peripheral wall of the sucker, and the radius of the convex arc is 0.3R.

The generatrix of the circumferential wall of the sucker 2 is formed by two sections of curves in a smooth transition mode, the first section of curve is a position from the bottom end face of the sucker to the circumferential wall of the sucker, the axial height of the first section of curve is 0.974R, and the radius of the inner wall of the sucker is 1.34R; the second section of curve is a convex arc section with the outward-turned lip.

The sucker 2 is made of nylon materials and is in a similar duct shape, and the wall thickness is 1 mm; the radius of the end surface at the bottom end is 0.996R; taking the end face of the bottom end of the sucker 2 as a reference, wherein the axial height h of the middle point of the paddle disk is 0.6R, and the radius d of the inner wall of the sucker corresponding to the height of the paddle disk is 1.04R; the minimum clearance s between the propeller tip of the propeller and the inner wall of the suction disc is 2.33% of the diameter of the propeller disc; the axial height of the vertex of the lip of the sucking disc is 0.51 time of the diameter of the paddle disc, and the radius D/2 of the circumference where the vertex is located is 1.576R.

Example (b):

when the wall climbing robot works, the motor drives the propeller to rotate at a high speed in the sucker 2, the dynamic pressure rises and the static pressure drops according to the Bernoulli principle, and the static pressure difference is caused by the speed difference of the upper surface and the lower surface of the blade, so that the thrust action is generated; under the suction effect of the propeller, a large amount of airflow is sucked into the sucker along the axial direction of the sucker, the flow velocity of the airflow inside the inlet section of the sucker is greatly improved, the pressure is lower than the external atmospheric pressure of the sucker, certain negative pressure is generated in the sucker, and therefore the sucker is enabled to be under the pressure of the atmospheric action. The direction of the thrust is consistent with the direction of the pressure, so the resultant force of the thrust and the pressure is the aerodynamic force of the designed aerodynamic force adsorption device.

In addition, the invention aims at realizing the flying of the robot, so that for the total weight of 450g of the total weight of the robot, the rotor wing adopts a common duct paddle of an unmanned aerial vehicle, a Gemfan D63 three-blade paddle, the radius of a maximum paddle disk is about 31.6mm, and the maximum thickness is 10 mm. The motor adopts TMOTOR F1404 matched with a 2.5-inch paddle, has the maximum power of 316W and has the weight of less than 10 g.

For the aerodynamic force adsorption device designed in the invention, the adsorption force is the nonlinear superposition of thrust and negative pressure, when the aerodynamic force adsorption device is close to a wall surface for adsorption, the gap between a lip and the wall surface is too large, so that the negative pressure in the sucker is reduced, the adsorption performance is reduced, the gap is too small, the thrust is greatly weakened, and the adsorption capacity is also reduced, so that the most appropriate gap needs to be determined, and the adsorption force is maximized. In addition, because four sets of aerodynamic force adsorption device have been used during the global design of robot, and the mechanism design of crawling is the double-wheel type, therefore only rely on wheel control lip and wall clearance will be difficult to guarantee that four sucking discs are the same with the clearance of wall all the time to make the adsorption affinity unstable, consequently need add a gap on the sucking disc and prescribe a limit to structure 1 so that every sucking disc 2 is the same with the interval of wall all the time. The gap limiting structure 1 finally designed after theoretical simulation calculation and experiment by considering the influence of friction force is a circular arc-shaped protrusion above the lip of the sucker 2, the maximum height of which is 3mm, namely, the optimal adsorption gap is 3 mm.

The connecting seat 4 is made of a carbon plate and comprises a motor base with the diameter of 18mm and a suction cup mounting base with the minimum radius of 31.537, and the motor base is riveted with the motor. Similar to the duct, the aerodynamic force generated by the aerodynamic force adsorption device in the invention is also influenced by the air flow condition at the air outlet of the sucker, but the motor and the propeller cannot be directly fixed in the sucker, so that the motor base and the sucker mounting base are required to be connected and need certain strength, and therefore, on the basis of ensuring the air flow as much as possible, the motor base is connected with the sucker mounting base through three common ribs and one reinforcing rib, the ribs are assembled with the mortises reserved at the bottom end of the sucker, and the sucker is fixed on the machine body through the mounting base.

When the robot is changed from a flight mode to a wall surface adsorption mode, the sucker 2 is required to have one-time impact with the wall surface, but in order to ensure the weight of the whole adsorption device, the wall thickness of the sucker is only 1mm in design, so that the sucker is made of a nylon material with better strength and toughness and is in a similar duct shape comprising a propeller and a motor. For a general ducted propeller device, the aerodynamic force of the ducted propeller device is mainly influenced by parameters such as the radius of a ducted lip and the clearance between a propeller tip and a duct, so that in order to improve the aerodynamic characteristics of the ducted propeller device, a large amount of theoretical calculation and experimental verification are carried out on the parameters, and finally determined sucker parameters are as follows: the radius of the inner wall at the bottommost part is 30.537mm, 4 corresponding mortises with the height of 3mm are arranged at the bottom end according to the thickness and the positions of the ribs, the height of the center of the paddle tray is 19mm by taking the bottommost part of the sucker as a reference, the radius of the inner wall of the duct is 33.3mm, namely the minimum gap between the paddle tip and the inner wall of the duct is 2.33 percent of the diameter of the paddle tray; the height of the fixed point of the lip of the sucking disc is 35.572mm, and the radius of the inner wall is 49.813 mm; at a height of 30.764mm, the radius of the inner wall of the suction cup is 42.4mm, and the line from the lowermost end to the point where the suction cup is smoothly curved continues upward where the suction cup forms a semi-arc lip with an eversion radius of 9.533 mm.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the principle and spirit of the present invention.

Claims (10)

1. A aerodynamic force adsorption device for realizing the flight of a wall-climbing robot comprises a sucker, a motor, a propeller and a connecting seat, wherein the bottom end of the sucker is connected with a robot body through the connecting seat; the motor is coaxially arranged on the connecting seat, an output shaft of the motor is coaxially connected with the propeller, the propeller is coaxially arranged in the sucker, and the radius of a paddle disk of the propeller is R; the method is characterized in that: the device also comprises a gap limiting structure, wherein the gap limiting structure is a hemispherical protrusion arranged on the surface of the lip of the sucker and used for limiting the distance between the sucker and the wall surface, and the axial height H of the gap limiting structure is 5% of the diameter of the pulp disk;

the peripheral wall of the sucker is of an expansion structure from the bottom end to the lip opening along the axial direction; the lip is turned outwards, and the axial section of the lip is a convex arc section with the circle center positioned outside the peripheral wall of the sucker.

2. An aerodynamic adsorption device for realizing the flight of a wall-climbing robot according to claim 1, characterized in that: the radius of the end face of the bottom end of the sucker is 0.996R; taking the end face of the bottom end of the sucker as a reference, wherein the axial height h of the middle point of the paddle disc is 0.6R, and the radius d of the inner wall of the sucker corresponding to the height of the paddle disc is 1.04R; the minimum clearance s between the propeller tip of the propeller and the inner wall of the suction disc is 2.33% of the diameter of the propeller disc; the axial height of the vertex of the lip of the sucking disc is 0.51 time of the diameter of the paddle disc, and the radius D/2 of the circumference where the vertex is located is 1.576R.

3. An aerodynamic adsorption device for realizing the flight of a wall-climbing robot according to claim 1, characterized in that: the radius of the convex arc of the axial section of the lip is 0.3R.

4. An aerodynamic adsorption device for realizing the flight of a wall-climbing robot according to claim 1, characterized in that: the generatrix of the circumferential wall of the sucker is formed by two sections of curves in a smooth transition mode, the first section of curve is a position with the axial height of 0.974R from the bottom end face of the sucker to the circumferential wall of the sucker, and the radius of the inner wall of the sucker is 1.34R; the second section of curve is a convex arc section with the outward-turned lip.

5. An aerodynamic adsorption device for realizing the flight of a wall-climbing robot according to claim 1, characterized in that: the gap defining structure is a bull-eye bearing.

6. An aerodynamic adsorption device for realizing the flight of a wall-climbing robot according to claim 1, characterized in that: the connecting base comprises a motor base and a sucker mounting base, and the motor base is positioned in the center; the sucking disc installation base is semicircle ring structure, and its inner peripheral face is fixed in motor base's periphery through 3 ordinary ribs coaxial that set up along circumference.

7. An aerodynamic adsorption device for realizing the flight of a wall-climbing robot according to claim 1, characterized in that: and reinforcing ribs are also arranged between the motor base and the sucker mounting base.

8. An aerodynamic adsorption device for realizing the flight of a wall-climbing robot according to claim 1, characterized in that: the diameter of the motor base is 0.57R, and the diameter of the disk mounting base is 0.998R.

9. An aerodynamic adsorption device for realizing the flight of a wall-climbing robot according to claim 1, characterized in that: the bottom end circumference of the sucker is provided with mortises which correspond to the positions of the ribs on the connecting seat one by one and are matched with each other for installation, so that the sucker and the connecting seat are fixed.

10. An aerodynamic adsorption device for realizing the flight of a wall-climbing robot according to claim 9, characterized in that: the axial height of the mortise is 0.09R.

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