CN109774810B - Wheel leg conversion device based on electromagnetic control and space reverse cam - Google Patents

Abstract

The present invention relates to the field of mobile robots. The technical proposal is as follows: a wheel leg conversion device based on electromagnetic control and space reverse cam is characterized in that: the device comprises a rotating frame, three leaf-shaped unfolding wheels and a wheel leg changing mechanism, wherein the rotating frame is rotatably positioned on a bearing seat through a central shaft, the three leaf-shaped unfolding wheels are respectively arranged in the rotating frame through mounting shafts, and the wheel leg changing mechanism is used for driving the leaf-shaped unfolding wheels to rotate; the blade-shaped unfolding wheel comprises an arc-shaped blade, a cylindrical cam rotatably positioned on the mounting shaft and a connecting rod for connecting the arc-shaped blade and the cylindrical cam; the wheel leg changing mechanism comprises a sliding groove arranged on the cylindrical cam, a supporting frame slidably positioned in the rotating frame, three follower wheels rotatably positioned on the outer circumferential surface of the supporting frame and respectively embedded in the sliding grooves of the cylindrical cam, and a driving structure for driving the supporting frame to slide. The device has the characteristics of low manufacturing cost, simple control, good dynamic performance and less required drive.

Description

A wheel-leg transformation device based on electromagnetic control and spatial anti-cam

Technical field

The invention relates to the field of mobile robots, specifically a wheel-leg transformation device based on electromagnetic control and spatial inverse cylindrical cam.

Background technique

Wheeled robots have fast movement speed, good passability in flat environments, and smooth operation, but have poor adaptability to complex environments. Legged robots have good obstacle-crossing performance, good adaptability to unknown environments, are relatively flexible, and have little damage to the ground. However, legged robots have complex structures, difficult control, and slow speeds. Compared with the general mobile robot mobile structure, the wheel-legged mobile robot has the advantages of both wheels and legs, including good obstacle surmounting performance, strong environmental adaptability, and fast traveling speed. Therefore, wheel-leg mechanisms, as the mobile structure of mobile robots, are increasingly widely used and researched in the field of mobile robots. Specific application areas include earthquake rescue, field detection, pipeline inspection, etc.

In unstructured environments, mobile robots need a mobile mechanism with fast movement speed and good obstacle surmounting ability. The wheel-legged structure combines the fast movement speed of the wheeled structure with the strong environmental adaptability of the legged robot. Therefore, a wheel-legged mechanism that combines the advantages of wheeled and legged mechanisms was developed. Among them, the wheel-leg conversion mechanism is an important category and has high engineering application value.

The existing invention patents for wheel-leg conversion mechanisms (such as CN 107323562A, CN 103142361B, etc.) all have the characteristics of complex structure, high manufacturing cost, excessive number of drives required, complex control, and poor dynamic performance. Therefore, it is necessary to propose a wheel-leg conversion mechanism that has low manufacturing cost, simple control, good dynamic performance, and requires less driving.

Contents of the invention

The object of the present invention is to overcome the deficiencies in the above background technology and provide a wheel leg conversion device based on electromagnetic control and spatial inverse cylindrical cam. The device should have low manufacturing cost, simple control, good dynamic performance, and less driving required. Features.

The technical solution of the present invention is:

A wheel leg conversion device based on electromagnetic control and spatial anti-cam, which is characterized in that: the device includes a rotating frame rotatably positioned on the bearing seat through a central axis, and three blades respectively arranged in the rotating frame through a mounting shaft. The leaf-shaped unfolding wheel and the wheel leg conversion mechanism used to drive the leaf-shaped unfolding wheel to rotate;

The leaf-shaped unfolding wheel includes arc-shaped blades, a cylindrical cam rotatably positioned on the installation shaft, and a connecting rod connecting the arc-shaped blades and the cylindrical cam;

The wheel leg conversion mechanism includes a sliding groove provided on the cylindrical cam, a support frame slidably positioned in the rotating frame, and three parts rotatably positioned on the outer circumferential surface of the support frame and respectively embedded in the sliding grooves of each cylindrical cam. A follower wheel and a driving structure for driving the sliding support frame;

The rotating frame includes two side wheels (5) fixed on the central shaft (14) at a certain distance from each other and installation shafts with both ends respectively positioned on the two side wheels and parallel to the axis of the central shaft; three installation shafts. The shafts are evenly distributed around the central axis, and the support frame is slidably positioned on the central axis;

The rotation axis of the rotating frame, the rotating axis of the cylindrical cam and the sliding direction of the supporting frame are parallel to each other, and the rotating axis of the follower wheel is perpendicular to the rotating axis of the rotating frame; when the supporting frame slides, it can drive the three cylindrical cams to rotate synchronously. The leaf-shaped unfolding wheel is converted between a wheel-shaped structure and a leg-shaped structure.

The driving structure includes two permanent magnets fixed on both sides of the support frame in the sliding direction, two springs that exert two opposite thrusts parallel to the sliding direction on the support frame, and an electromagnet fixed on one end of the rotating frame to cooperate with the permanent magnets.

The installation shaft is rotatably positioned in the side wheel, and the cylindrical cam is coaxially fixed with the installation shaft.

The electromagnet is fixed to one of the side wheels; the two springs are sleeved on the central shaft and are respectively arranged between the side wheel and the permanent magnet.

The wheel leg conversion mechanism is also provided with a limiting structure for preventing the rotation of the support frame; the limiting structure includes a slide rail with two ends fixed to the two side wheels respectively and parallel to the sliding direction of the support frame, and a slide rail arranged on the support frame. The slider matches the slide rail.

When the electromagnet is not energized, the support frame is located in the middle of the central axis, and the three leaf-shaped unfolding wheels are combined into a circular wheel-shaped structure; when the electromagnet is energized, the support frame is displaced to drive the cylindrical cam, and the three leaf-shaped unfolding wheels are The shaped unfolding wheel is combined into a leg-shaped structure with three supporting legs.

The beneficial effects of the present invention are:

The invention proposes a wheel-leg conversion device, which can realize the conversion between the wheel-shaped structure and the leg-shaped structure, and has the advantages of good flat ground passing performance, fast speed, smooth operation of the wheeled robot and good obstacle-crossing performance of the legged robot. ; The use of adjustable electromagnets for wheel leg conversion control reduces the use of motors compared with traditional conversion methods, and the remote non-contact control conversion can ensure that the control part can be completely installed on the body, greatly reducing the cost of the wheel leg conversion device The quality has greatly improved the dynamic characteristics and increased the load capacity; the structure of the reverse cylindrical cam is used to convert the linear displacement of the support frame into the angular displacement of the blade-shaped unfolding wheel, and there is a linear corresponding relationship between the linear displacement and the angular displacement. Greatly simplifies the control difficulty.

Description of the drawings

Figure 1 is one of the isonometric views of the present invention.

Figure 2 is the second isometric view of the present invention.

Figure 3 is the third isometric view of the present invention (one leaf-shaped unfolding wheel is omitted).

Figure 4 is a schematic front view of the structure of the present invention (one leaf-shaped unfolding wheel is omitted).

Figure 5 is one of the left structural schematic diagrams of the present invention (wheel-shaped structure).

Figure 6 is the second left structural diagram of the present invention (leg-shaped structure).

Figure 7 is a schematic diagram of the driving structure and the limiting structure in the present invention.

Figure 8 is a schematic three-dimensional structural diagram of the leaf-shaped unfolding wheel in the present invention.

Figure 9 is a schematic three-dimensional enlarged structural diagram of the limiting structure in the present invention.

Figure 10 is a schematic three-dimensional structural diagram of the side wheel in the present invention.

Figure 11 is an assembly diagram of some parts of the present invention.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings, but the present invention is not limited to the following examples.

A wheel leg conversion device based on electromagnetic control and spatial anti-cam, including a bearing seat 3, a rotating frame, three leaf-shaped unfolding wheels 1 and a wheel leg conversion mechanism.

The rotating frame includes a central shaft 14 rotatably positioned on the bearing seat, two side wheels 5 fixed on the central shaft at a certain distance from each other, and three mounting shafts 6 at both ends respectively positioned on the two side wheels. ; The central shaft and the installation shaft are both parallel to the rotation axis of the side wheel (the rotation axis of the side wheel is the rotation axis of the central shaft), the central shaft and the side wheel are coaxially fixed, and the installation shaft is evenly distributed around the central shaft; the installation shaft The two ends are also rotatably positioned in the side wheels through bearings 16, and the bearing ends are also equipped with bearing retaining rings 12.

The side wheels are fixed on the central shaft through the bushing 2.1 in the middle (fixed by screws passing through the bushing radially); the bushing of one of the side wheels also extends axially to the outside of the bearing seat, and is made with a keyway 2.2 , used to connect (through coupling) external power for torque transmission and drive the entire rotating frame to rotate. The central shaft is a stepped shaft with threads at both ends. The outer diameter of the end of the central shaft is smaller than the outer diameter of the middle part of the central shaft. The two ends of the central shaft also pass through the side wheels and are fixed by locking nuts 4.

The three leaf-shaped unfolding wheels 1 are arranged in a rotating frame, and each leaf-shaped unfolding wheel includes an arc blade 1.1, a cylindrical cam 1.2 and a connecting rod 1.3. The cylindrical cam is provided with an axis hole (omitted in the figure) for the installation shaft to pass through. The cylindrical cam and the installation shaft are coaxially fixed (preferably connected by a key), so that the cylindrical cam is rotatably positioned in the two side wheels, and the cylindrical cam is rotatably positioned in the two side wheels. The outer circumferential surface of the cam is also provided with a sliding groove 1.4. One end of the connecting rod is fixed to the cylindrical cam, and the other end is fixed to the middle part of the inner arc surface of the arc blade.

The wheel-leg conversion mechanism is used to drive the leaf-shaped unfolding wheel to rotate, so that the leaf-shaped unfolding wheel switches between the wheel-shaped structure and the leg-shaped structure. The wheel leg conversion mechanism includes a sliding groove provided on the cylindrical cam, a support frame 9 slidably positioned on the rotating frame (specifically on the central axis of the rotating frame), and a supporting frame 9 rotatably positioned on the outer circumferential surface of the supporting frame. Three follower wheels 13, a driving structure for driving the support frame to slide along the central axis, and a limiting structure for preventing the support frame from rotating around the central axis.

The follower wheel is rotatably positioned at one end of the follower wheel shaft through a bearing, and is embedded in the cylindrical cam sliding groove. The rotation axis of the follower wheel is perpendicular to the rotation axis of the rotating frame; the other end of the follower wheel shaft is made with external threads. Screw it into the screw hole on the outer circumference of the support frame (as can be seen from the picture: there are three follower wheel axles, and the axes of the two follower wheel axles are arranged at 180 degrees on the cross section of the support frame). The matching relationship between the follower wheel and the cylindrical cam is a spatial anti-cylindrical cam pair. When the driving structure pushes the support frame to slide, the cylindrical cam can be driven to cause the three leaf-shaped unfolding wheels to rotate synchronously.

The driving structure includes permanent magnets 8 fixed on both sides of the support frame, two springs 7 that exert thrust on the support frame, and an electromagnet 2 fixed to one of the side wheels.

Two permanent magnets are arranged on both sides of the support frame in the sliding direction (the two permanent magnets are fixed on the two end faces of the support frame in the sliding axis direction through screws). When installing the permanent magnets, ensure that the magnetic poles correspond in space so that the magnets The sense line is closed to avoid magnetic cancellation. The springs are threaded on the central axis and are respectively arranged between the side wheels and the permanent magnets. The springs exert two thrusts on the support frame parallel to the sliding direction and in opposite directions. The electromagnet is an annular electromagnet powered by an external device, which can provide a variable magnetic field. The electromagnet adjusts the position of the support frame on the central axis through the cooperation of permanent magnets.

The limiting structure includes a slide rail 11 fixed in the two side wheels and parallel to the central axis, and a slide block 15 arranged on the support frame to cooperate with the slide rail; as can be seen from the figure: the slide block is fixed on the outer circumferential surface of the support frame. on the top, located between the two follower wheel axles.

The working principle of the present invention is:

The external power drives the rotating frame and the leaf-shaped unfolding wheel to rotate through the side wheels, driving the robot to move; when it needs to run on a flat ground, the invention converts to a wheel-shaped structure; at this time, the electromagnet is not energized, and the support frame is on the top of the springs on both sides. Press down the middle position of the central axis (the support frame maintains a balanced position under the force of the magnetic field and the force of the spring), and the three leaf-shaped unfolding wheels are combined into a circular wheel-shaped structure (as shown in Figure 5, the leaves form a circle (shaped outline) to ensure that the robot has good passability; when encountering an obstacle, if you continue to maintain the wheel-shaped structure, it may not be able to overcome the obstacle, so that the electromagnet is energized to generate a magnetic field to push the support frame to move a certain distance along the central axis (support The movement of the frame breaks the balance between the magnetic field force and the spring force), thus forcing the leaf-shaped unfolding wheel to rotate at a certain angle (as shown in Figure 6). One end of the blade unfolds outward as a supporting leg in contact with the ground. Three leaf-shaped unfolding wheels are combined into a leg-shaped structure with three supporting legs, thus ensuring the ability to pass on complex ground.

Claims (3)

1. A wheel leg conversion device based on electromagnetic control and space reverse cam is characterized in that: the device comprises a rotating frame, three leaf-shaped unfolding wheels (1) and a wheel leg changing mechanism, wherein the rotating frame is rotatably positioned on a bearing seat (3) through a central shaft (14), the three leaf-shaped unfolding wheels (1) are respectively arranged in the rotating frame through mounting shafts (6), and the wheel leg changing mechanism is used for driving the leaf-shaped unfolding wheels to rotate;

the blade-shaped unfolding wheel comprises an arc-shaped blade (1.1), a cylindrical cam (1.2) rotatably positioned on the mounting shaft and a connecting rod (1.3) for connecting the arc-shaped blade and the cylindrical cam;

the wheel leg changing mechanism comprises sliding grooves (1.4) arranged on the cylindrical cams, a supporting frame (9) slidably positioned in the rotating frame, three follower wheels (13) rotatably positioned on the outer circumferential surface of the supporting frame and respectively embedded in the sliding grooves of the cylindrical cams, and a driving structure for driving the supporting frame to slide;

the rotating frame comprises two side wheels (5) fixed on a central shaft (14) at a certain distance from each other and a mounting shaft with two ends respectively positioned on the two side wheels and parallel to the axis of the central shaft; the three mounting shafts are uniformly distributed around the central shaft, and the support frame is slidably positioned on the central shaft;

the rotation axis of the rotating frame, the rotation axis of the cylindrical cam and the sliding direction of the supporting frame are parallel to each other, and the rotation axis of the follower wheel is perpendicular to the rotation axis of the rotating frame; when the support frame slides, the three cylindrical cams can be driven to synchronously rotate, so that the leaf-shaped unfolding wheel is converted between a wheel-shaped structure and a leg-shaped structure;

the driving structure comprises two permanent magnets (8) fixed on two sides of the sliding direction of the support frame, two springs (7) for applying two opposite thrust forces parallel to the sliding direction to the support frame, and an electromagnet (2) fixed at one end of the rotating frame and matched with the permanent magnets;

the wheel leg conversion mechanism is also provided with a limiting structure for preventing the support frame from rotating; the limiting structure comprises a sliding rail (11) with two ends fixed with the two side wheels respectively and parallel to the sliding direction of the support frame and a sliding block (15) arranged on the support frame and matched with the sliding rail;

when the electromagnet is not electrified, the support frame is positioned in the middle of the central shaft, and the three leaf-shaped unfolding wheels are combined into a round wheel-shaped structure; when the electromagnet is electrified, the support frame is displaced so as to drive the cylindrical cam, and the three leaf-shaped unfolding wheels are combined into a leg-shaped structure with three support legs;

the matching relation between the follower wheel and the cylindrical cam is a space reverse cylindrical cam pair; when the driving structure pushes the supporting frame to slide, the cylindrical cam can be driven to further enable the three leaf-shaped unfolding wheels to synchronously rotate.

2. The wheel leg conversion device based on electromagnetic control and space inverse cam according to claim 1, wherein: the mounting shaft is rotatably positioned in the side wheel, and the cylindrical cam is coaxially fixed with the mounting shaft.

3. A wheel leg conversion device based on electromagnetic control and space inverse cam according to claim 2, characterized in that: the electromagnet is fixed with one of the side wheels; the two springs are sleeved on the central shaft and are respectively arranged between the side wheels and the permanent magnets.