CN106915204B - A kind of pneumatic software traveling wheel of deformable non-circular rolling - Google Patents

Abstract

A deformable non-circular rolling pneumatic soft walking wheel comprises an outer ring, an inner ring, an outer support rod, an inner support rod, a fluid driver, an air pipe and an air pump. The contour line of the outer section of the outer ring is a regular N-gon. The air pump and the inner ring are connected by several inner support rods, and the outer ring and the inner ring are connected by several outer support rods. Each mounting surface Two fluid drivers are arranged side by side on the top, and one end of each fluid driver is fixedly connected with the mounting surface to form a fixed end; each fluid driver includes a strain-limited bottom layer and an elastomer layer that are fixedly connected to each other, and the strain-limited bottom layer can be connected with the installation surface. The fixed surface is in contact with each other, and the elastic body layer can be in contact with the road surface, and the elasticity of the elastic body layer is greater than that of the strain-limited bottom layer; an air pipe is arranged in each elastic body layer. The invention can overcome the disadvantages of poor passability and poor running stability of the existing road wheels in complex environments, so as to improve the adaptability and good stability of the wheels on complex terrains.

Description

A Deformable Noncircular Rolling Pneumatic Soft Walking Wheel

technical field

The invention relates to a walking mechanism of a robot, in particular to a deformable non-circular rolling pneumatic soft walking wheel.

Background technique

With the continuous advancement of scientific exploration, robots need to operate in more complex environments, such as planetary exploration robots, military robots and other mobile robots for field operations. The wild terrain environment may be rough, with rocks or depressions, and the complex terrain tests the robot's travel system.

The current robot walking mechanism is generally composed of rigid materials and adopts circular rolling, such as the all-terrain walking wheel (patent number 201520214064.1) researched and designed by Wuhan University. The middle of this walking wheel is a mechanical wheel with a central axis, and the outside is fixed There are several elastic serrated metal sheets. By changing the position of the connecting rod in the cam of the mechanical wheel, the metal sheet can be deformed to adapt to complex terrain in non-structural environments such as sandy land, and the design requirements can be achieved.

Yet above-mentioned robot walking mechanism still exists following deficiency:

1. Poor shock-absorbing ability and poor stability: When walking on a rough road, there will be a large vibration or shaking due to the roughness of the running road. When the robot with this walking mechanism is loaded with precision equipment, due to the aforementioned large vibration or shaking, it will have a great impact on the measurement accuracy of the internal instruments, and in serious cases, it may also cause damage to its internal equipment.

2. Poor climbing performance: When the slope of the contact surface between the wheel and the rough ground or obstacles is too large (more than 20%), the friction between the wheel and the contact surface will be too small, and then slipping will result in poor passability or even inability to walk, etc. Happening.

3. Poor environmental adaptability: The adaptability to unknown environments is low. Due to the use of rigid materials and the fixed wheel form, the wheel shape and diameter cannot be changed arbitrarily to adapt to the environment, and it is also impossible to pass through complex spaces such as caves and obstacles below its height.

4. If flexible devices such as tires are not used on the outside of the wheel, the rigid material outside the wheel may cause certain damage to the space it passes through and cause certain damage to the ecology. At the same time, solid obstacles such as gravel on rough roads will also cause certain damage to the external rigid materials of the running gear, resulting in a greatly reduced service life.

5. Generally, the traveling mechanism will install an external shock-absorbing mechanism on the wheels, but the structure of the external shock-absorbing mechanism is complex, the manufacturing cost is high, and the repair after damage is cumbersome.

Therefore, in order to solve the above problems, it is necessary to address the high dynamic characteristics and strong environmental adaptability of the mobile system in complex terrain such as rough roads. The existing road wheels have the disadvantages of poor passability and poor driving stability in complex environments, so as to improve the adaptability and good stability of the wheels on complex terrain.

Contents of the invention

The technical problem to be solved by the present invention is to provide a deformable non-circular rolling pneumatic soft walking wheel in view of the above-mentioned deficiencies in the prior art. The deformable non-circular rolling pneumatic soft walking wheel can overcome the complex There are disadvantages of poor passability and poor driving stability in the environment, so as to improve the adaptability and good stability of the wheels on complex terrain.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

A deformable non-circular rolling pneumatic soft walking wheel comprises an outer ring, an inner ring, an outer support rod, an inner support rod, a fluid driver, an air pipe and an air pump.

The contour line of the outer section of the outer ring is a regular N-gon, that is, the outer side of the outer ring has N mounting surfaces of equal length and N junction points, wherein N≥3.

The outer ring, inner ring and air pump are arranged concentrically from the outside to the inside; the air pump and the inner ring are connected by several inner support rods, the outer ring and the inner ring are connected by several outer support rods, and the outer support rods and The number of the inner support rods is equal to the number of the mounting and fixing surfaces; the outer support rods and the inner support rods are both hollow structures and communicate with each other.

Two fluid drivers are arranged side by side on each fixing surface, and the two fluid drivers are respectively a clockwise fluid driver and a counterclockwise fluid driver; one end of each fluid driver is directly fixedly connected to one end of the corresponding fixing surface to form a fixed end; the fixed end of the clockwise fluid driver and the fixed end of the counterclockwise fluid driver are located at different ends of the corresponding mounting surface.

Each fluid driver includes a strain-limited bottom layer and an elastic body layer fixedly connected to each other. The strain-limited bottom layer can be in contact with the mounting surface, and the elastic body layer can be in contact with the road surface. The elasticity of the elastic body layer is greater than that of the strain-limited bottom layer.

Each elastomer layer is provided with a trachea, and the trachea passes through the elastomer layer located at the fixed end side, and then passes through the corresponding junction point on the outer ring, the hollow cavity of the outer support rod, the inner ring and the inner support rod. After the hollow cavity, it is connected with the air pump.

The outer ring is made of elastic material, and the elasticity of the outer ring is smaller than that of the elastic body layer.

The length of each outer support rod can be stretched, and each outer support rod is provided with a linear telescopic drive device.

The linear telescopic driving device is a telescopic motor or a telescopic cylinder.

The other end of each fluid holder is connected with the other end of the corresponding mounting and fixing surface through an elastic member to form an elastic contact end.

The elastic member is a spring or a rubber band.

Several cavities are arranged in the elastic body layer, and each cavity communicates with the trachea protruding into the elastic body layer.

Several top layer grooves are arranged on the outer top surface of each fluid driver.

The side of each fluid driver is provided with several side grooves.

After the present invention adopts the above structure, it has the following beneficial effects:

1. The invention adopts soft material, compared with traditional rigid material, it not only overcomes the disadvantages of the traditional rigid wheel being large and bulky, but also has better performance in environmental adaptability, and can operate in working environments such as rough roads or soft roads . The invention has sufficient environmental adaptability, can be compatible with obstacles or the surrounding environment through the deformation of its own soft material, and can move flexibly in a limited space, thereby better adapting to the environment.

2. The appearance of the pneumatic soft walking wheel is approximately circular, and the traveling mode is rolling. Compared with some traveling modes such as creeping or crawling, when walking on rough roads, the contact area with the road is smaller, the friction force is relatively small, and the traveling resistance is relatively relatively Smaller and more energy efficient.

3. Pneumatic soft walking wheels are driven by multiple fluid drivers, and the wheels are moved through the deformation and bending of the fluid drivers. One fluid driver can make the wheels move forward (or backward) one step, and the rolling and walking step by step, the control accuracy is relatively high. It is more accurate than ordinary circular rolling; at the same time, the top groove, side groove and non-circular rolling motion on the fluid driver will exert greater pressure on rough roads than circular rolling, and the friction will also increase relatively. Reduce the possibility of slippage.

4. The ability to overcome obstacles is good. Since it is composed of soft materials, when walking on rough terrain, the external soft materials can play a role in cushioning and shock absorption. When it is necessary to pass through a robot that is lower than the walking wheel or has a walking wheel body In the narrow space with high height, it can adapt to the environment through the expansion and contraction of the outer support rod and the deformation of the outer ring, without redesign and manufacture.

5. Relying on external soft materials for shock absorption has a simple structure, instead of relying on an external shock absorbing mechanism for traditional rigid wheels, the structure is simple and more independent.

6. The design is simple, the working principle is concise and easy to understand, the raw material price can be low in practical application, and the manufacturing process is simple and easy to realize.

7. The driving of the traveling wheels can be realized only through the fluid drive, the driving method is simple and clean, easy to implement, and will not cause any pollution to the environment, energy saving and environmental protection.

Description of drawings

Fig. 1 shows a schematic structural view of a deformable non-circular rolling pneumatic soft walking wheel of the present invention.

Fig. 2 shows a side view of a deformable non-circular rolling pneumatic soft walking wheel of the present invention.

Figure 3 shows a cross-sectional view of the fluid actuator of the present invention.

Figure 4 shows the assembled view of the clockwise fluid driver and the counterclockwise fluid driver.

Figure 5 shows a diagram of the orientation of the air tube in the fluid drive.

Figure 6 shows the motion state diagram of the pneumatic soft walking wheel when it is walking normally.

Fig. 7 shows a schematic diagram of the deformation of the pneumatic soft walking wheel of the present invention when it encounters an obstacle.

Fig. 8 shows a schematic diagram of the local deformation of the pneumatic soft walking wheel of the present invention.

Fig. 9 shows the schematic diagram when the pneumatic soft walking wheel of the present invention has just come into contact with a cave or the like.

Fig. 10 shows a schematic diagram of the pneumatic soft walking wheel of the present invention passing through a cave after being lowered in height.

Fig. 11 shows the mechanical plane analysis diagram when the rigid wheel climbs a slope in the prior art.

Fig. 12 shows the mechanical plane analysis diagram when the deformable non-circular rolling pneumatic soft walking wheel of the present invention climbs a slope.

Fig. 13 shows a material structure diagram of the fluid actuator of the present invention.

Including:

1. Fluid driver; 2. Outer ring; 3. Telescopic motor; 4. Outer support rod; 5. Inner ring; 6. Gas pipe; 7. Inner support rod; 8. Air pump; 9. Battery; 10. Elastomer layer; 11. Side groove; 12. Strain limiting bottom layer; 13. Top layer groove; 17. Air cavity; 18. Clockwise fluid driver; 19. Counterclockwise fluid driver.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific preferred embodiments.

As shown in Figures 1 and 2, a deformable non-circular rolling pneumatic soft walking wheel includes an outer ring 2, an inner ring 5, an outer support rod 4, an inner support rod 7, a fluid driver 1, an air pipe 6 and an air pump 8 .

The contour line of the outer section of the outer ring is a regular N-gon, that is, the outer side of the outer ring has N mounting surfaces of equal length and N junction points, wherein N≥3.

The contour line of the outer section of the outer ring is preferably a positive octagonal deformation, that is, the outer side of the outer ring has eight mounting and fixing surfaces with equal lengths and eight junction points.

The setting of the above-mentioned regular N-gon makes the fluid driver easy to install, and the rolling frequency is consistent and the control precision is high.

As an alternative, the contour line of the outer section of the outer ring can also be a regular pentagon or a regular hexagon, etc., all of which are within the protection scope of the present invention.

The outer ring 2, the inner ring 5 and the air pump 8 are arranged concentrically from the outside to the inside, the air pump is arranged at the center of the circle, the inner ring is arranged concentrically on the outer periphery of the air pump, and the outer ring is arranged concentrically on the outer periphery of the inner ring.

The air pump and the inner ring are connected by a number of inner support rods 7, and the outer ring and the inner ring are connected by a number of outer support rods 4. The number of outer support rods and inner support rods is equal to the number of mounting surfaces , are preferably 8.

As shown in Figure 8, the eight outer support rods are respectively 4a, 4b, 4c, 4d, 4e, 4f, 4g and 4h.

The inner ring, the outer support rod and the inner support rod are all made of rigid material. Therefore, it can support equipment such as air pumps and batteries, and prevent equipment from being damaged due to deformation of the walking element.

N through holes are evenly distributed on the inner ring, preferably eight, to facilitate the fixed connection of the outer support rod and the inner support rod. Both the outer support rod and the inner support rod are hollow structures, and communicate with each other after passing through corresponding through holes of the inner ring.

A trachea and a control circuit are communicated in the support frame. The air pump and battery in the inner ring are fixedly connected together

The length of each outer support rod is preferably telescopic, and each outer support rod is preferably provided with a linear telescopic drive device. It is driven by a linear telescopic drive device to expand and contract the length of the corresponding outer support rod. Further, each linear telescopic drive device is preferably a telescopic motor 3 or a telescopic cylinder or the like.

Further, the outer ring is preferably made of elastic material, and the elasticity of the outer ring is preferably smaller than that of the fluid driver.

Two fluid drivers 1 are arranged side by side on each mounting surface, and the two fluid drivers are respectively a clockwise fluid driver 18 and a counterclockwise fluid driver 19 .

One end of each fluid driver is preferably directly fixedly connected to one end of the corresponding mounting and fixing surface by means of bonding or the like to form a fixed end. The fixed end can prevent the drift of the fluid driver and the air pipe in the fluid driver.

The other end of each fluid holder is preferably connected to the other end of the corresponding mounting and fixing surface through an elastic member to form an elastic contact end. The elastic member is preferably a spring or a rubber band. The elastic member can assist the fluid holder to quickly return to its original position, that is, the position matched with the mounting and fixing surface.

As shown in FIG. 4 , the fixed end of the clockwise fluid driver and the fixed end of the counterclockwise fluid driver are located at different ends of the corresponding mounting surface.

As shown in Figure 13, each fluid actuator includes a strain-limiting bottom layer 12 and an elastomer layer 10 that are fixedly connected to each other. The strain-limiting bottom layer can be in contact with the mounting surface, and the elastomer layer can be in contact with the road surface. Greater than strain limits the elasticity of the bottom layer as well as the outer ring.

As shown in Figure 3, a trachea 6 is provided in each elastomer layer, and the trachea passes through the elastomer layer located at the fixed end side, and then passes through the corresponding handover point on the outer ring, the hollow cavity of the outer support rod, After the hollow cavity of the inner ring and the inner support rod, it is connected with the air pump.

Further, several cavities are preferably provided in the elastic body layer, and each cavity communicates with a trachea protruding into the elastic body layer.

Further, several top layer grooves 13 are preferably arranged on the outer top surface of each fluid driver.

Further, several side grooves 11 are preferably provided on the side of each fluid driver. The cavities 17 are preferably placed in side grooves.

The arrangement of the top layer groove 13 and the side groove 11 can make the elastic body layer deform more easily.

A fluid driver can control the wheel to move in one direction, and the two drivers can be assembled in reverse as shown in Figure 4 to make the wheel turn in two directions.

All the above-mentioned clockwise fluid drivers are enclosed to form a clockwise rim, and the air pump alternately inflates the clockwise fluid drivers to realize the clockwise rolling of the pneumatic soft walking wheel.

All the above-mentioned counterclockwise fluid drivers are enclosed to form a counterclockwise rim, and the counterclockwise rolling or braking of the pneumatic soft walking wheel can be realized by alternately inflating the counterclockwise fluid drivers through the air pump.

When the wheel needs to turn right, the bottom fluid driver in the clockwise rim is inflated, the cavity expands, and after the cavity expands, the elastomer layer is squeezed to produce a large deformation (bending), and the strain-limited bottom layer produces a small deformation (bending) ), the strain difference between the elastic body layer and the strain-limited bottom layer causes the fluid actuator to bend as shown in Figure 6, the road wheel rotates clockwise to the right, and the side touches the ground, and the cavity returns to the initial state after deflation, and the fluid actuator is in the When the cavity is squeezed, it returns to its original shape and completes the right turn movement.

Similarly, when it is necessary to turn left, it is enough to inflate the cavity in the bottom fluid driver in the counterclockwise rim.

When deceleration is required, reverse braking can be realized through the simultaneous operation of two circulation drivers, and the controller can obtain the magnitude of the braking force according to the current rotational speed, and change and control the filling volume of the inner cavity of the fluid driver opposite to the current direction of motion And the size of the speed to control the size of the braking force.

When acceleration is required, the controller can increase the speed of filling the inner cavity of the corresponding fluid driver.

When it is necessary to pass through the cave space below the height of the wheels, as shown in Figures 7 to 10, the telescopic motor 3 drives the outer support rod 4 to perform radial telescopic movement, and the outer support rod shrinks.

As shown in Figure 8, the outer support rods 4a, 4b, 4c are in a non-shortened state, ensuring that the lower half is a semicircle, which does not affect the walking of the wheels; Under the coordinated action, large deformation can be produced.

At the same time, the outer ring will have a large deformation to adapt to the expansion and contraction of the outer support rod, that is, the outer ring is pulled inward; the shape of the wheel changes accordingly, that is, the wheel is in a contracted state as a whole; the diameter of the wheel is reduced, and the height of the walking wheel is reduced . At the same time, the driver on the top is not inflated, so its rigidity is small. After being squeezed by an external force, the deformation shown in Figure 10 occurs, and finally the wheel easily passes through the narrow cave space.

And when traveling on sandy ground or soft ground, the pressure of the wheels on the road surface is Due to the use of soft materials, its mass is lighter than that of rigid materials, so the gravity G is smaller. At the same time, after the external fluid driver is pressurized, the contact area s between the deformation and the contact surface is larger, so the pressure is smaller, and the softness of sand, etc. The concave deformation caused by the ground will be smaller and more conducive to walking.

When analyzing the force on the whole, as shown in Figure 11, the rigid wheel in the prior art is used to climb the slope, and the slope of the climbing surface is α, because it is only affected by gravity G, friction force f and support force The role of N, so the plane mechanics equation of the rigid wheel is:

Vertically:

Friction force: f=μN=μcosa

Horizontal direction: F = _Gsina -f = Gsina-μGcosa = G(sina-μcosa)

It can be seen from the above equation that only when the friction force f is large enough can it run stably on the slope. The greater the slope, the less the support force of the slope to the wheels, and the corresponding decrease of the friction force. The level of gravity The component force Gsina increases accordingly, and the possibility of the wheel sliding to the right increases.

As shown in Fig. 12, since the present invention has an additional support of a deformed fluid actuator, the frictional force is: f=μ(G+N ₂ ) cosa, and the resultant force _in the horizontal direction is: F = Gsina-μ(G+N ₂ )cosa. At this time, the friction force is obviously increased, and it can move at a larger slope angle.

If the coefficient of friction is set to 0.2, and the support force N ₂ of the fluid driver that bends after deformation is assumed to be 0.1G, after calculation, the traditional rigid wheel can climb a slope with a slope angle of 11.3° (20% gradient) at most. However, the present invention can climb slopes with a slope angle of 12.4° (22% gradient), and has wider applicability.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be carried out to the technical solutions of the present invention. These equivalent transformations All belong to the protection scope of the present invention.

Claims (9)

1. A deformable non-circular rolling pneumatic soft walking wheel, characterized in that: comprising an outer ring, an inner ring, an outer support rod, an inner support rod, a fluid driver, a trachea and an air pump; The contour line of the outer section of the outer ring is a regular N-gon, that is, the outer side of the outer ring has N mounting surfaces of equal length and N junction points, where N≥3; The outer ring, inner ring and air pump are arranged concentrically from the outside to the inside; the air pump and the inner ring are connected by several inner support rods, the outer ring and the inner ring are connected by several outer support rods, and the outer support rods and The number of inner support rods is equal to the number of mounting surfaces; the outer support rods and inner support rods are both hollow structures and connected to each other; Two fluid drivers are arranged side by side on each fixing surface, and the two fluid drivers are respectively a clockwise fluid driver and a counterclockwise fluid driver; one end of each fluid driver is directly fixedly connected to one end of the corresponding fixing surface to form a fixed end; the fixed end of the clockwise fluid driver and the fixed end of the counterclockwise fluid driver are located at different ends of the corresponding mounting surface; Each fluid driver includes a strain-limited bottom layer and an elastomer layer fixedly connected to each other, the strain-limited bottom layer can be in contact with the mounting surface, the elastomer layer can be in contact with the road surface, and the elasticity of the elastomer layer is greater than that of the strain-limited bottom layer; Each elastomer layer is provided with a trachea, and the trachea passes through the elastomer layer located at the fixed end side, and then passes through the corresponding junction point on the outer ring, the hollow cavity of the outer support rod, the inner ring and the inner support rod. After the hollow cavity, it is connected with the air pump. 2. The deformable non-circular rolling pneumatic soft walking wheel according to claim 1, characterized in that the outer ring is made of elastic material, and the elasticity of the outer ring is smaller than that of the elastomer layer. 3. The deformable non-circular rolling pneumatic soft walking wheel according to claim 2, characterized in that: the length of each outer support rod can be stretched, and each outer support rod is provided with a linear telescopic drive device. 4. The deformable non-circular rolling pneumatic soft walking wheel according to claim 3, characterized in that: the linear telescopic driving device is a telescopic motor or a telescopic cylinder. 5. The deformable non-circular rolling pneumatic soft walking wheel according to claim 1, characterized in that: the other end of each fluid driver is connected to the other end of the corresponding mounting and fixing surface through an elastic member to form an elastic contact end. 6. The deformable non-circular rolling pneumatic soft walking wheel according to claim 5, wherein the elastic member is a spring or a rubber band. 7. The deformable non-circular rolling pneumatic soft walking wheel according to claim 1, characterized in that: the elastic body layer is provided with several cavities, and each cavity is connected with a trachea extending into the elastic body layer Pass. 8. The deformable non-circular rolling pneumatic soft walking wheel according to claim 1, characterized in that: the outer top surface of each fluid driver is provided with several top layer grooves. 9. The deformable non-circular rolling pneumatic soft walking wheel according to claim 1, characterized in that: the side of each fluid driver is provided with several side grooves.