KR101845325B1 - 6 dof ball-driven robot with a 3 dof parallel kinematic manipulator - Google Patents

Abstract

A ball drive robot provided with a parallel mechanism of three degrees of freedom is disclosed. A ball driving robot having a three-degree-of-freedom parallel mechanism includes a ball constituting a robot body; A first table surrounding the sphere at a height lower than the center of the sphere and spaced apart from the sphere; A first motor provided on the first table and providing rotational force to the omni wheel; An omni wheel coupled to a shaft of the first motor unit and disposed below the first table; A second table disposed on the sphere; A first support coupled to the first table at one end and coupled to the second table at the other end; A control unit for controlling the first motor unit; A battery for supplying power to the first motor unit and the control unit; A third table disposed above the second table; A second support coupled to the second table at one end and coupled to the third table at the other end; And a parallel mechanism formed on the second table or the third table.

Description

(6 DOF BALL-DRIVEN ROBOT WITH A 3 DOF PARALLEL KINEMATIC MANIPULATOR WITH 3 DOF PARALLEL DEVICE}

The present invention relates to a ball driving robot provided with a 3 RRS or 3 RPS parallel mechanism, and more particularly to a ball driving robot in which a ball arrestor for supporting a ball is not used and an omni wheel is disposed at a lower portion of the ball so as to improve the balancing stability of the robot And a three-degree-of-freedom parallel mechanism that implements 6 degrees of freedom by mounting a 3 RRS or 3 RPS parallel mechanism on the ball.

The use of industrial robots is increasing on the wind of production automation and unmanned operation. Industrial robots increase productivity by performing dangerous and repetitive tasks accurately and consistently on behalf of people.

Especially, in the industrial field, the mobility of robots is required in various fields such as cleaning robots and service robots as well as transportation of goods, and the utilization of mobile robots is increasing.

1 is a perspective view of a conventional ball driving robot.

1, the ball driving robot, which is one of the mobile robots, is a mobile robot equipped with an omniwheel capable of rotating in all directions to drive the ball. The ball drive system having the omni wheel can have a much smaller structure than the conventional wheel drive system composed of four wheels, and can have large directionality and mobility such as being able to rotate in place without movement. It has small frictional force due to point contact or line contact with the ground, and has a smooth curved surface. In addition, since it is easy to switch the robot in a narrow space where the robot is difficult to move, the industry is paying attention to the ball driving robot.

However, as shown in FIG. 1, the conventional ball-driven robot has three spherical ball arresters 10 that surround spheres, and the omni-wheel is installed at the upper part of the sphere to have a high center of gravity have. The ball arrester is a structure that squeezes the ball with elasticity, and serves to always contact the ball with the omni wheel and the actuator portion placed on the top of the ball. Therefore, the conventional ball driving robot has a problem that the number of components to be manufactured is large and the height from the ground is relatively high, so that the balancing stability of the robot is low. In addition, the durability of the ball arrester's elasticity is a factor that determines the life of the robot and has a weakness in reliability.

On the other hand, in the industrial field, 6 degrees of freedom are often required for precise work. However, since the conventional ball driving robot is a three-degree-of-freedom robot capable of performing two-directional linear motion on the plane and rotational motion based on the axis perpendicular to the plane, it can not adequately cope with various operations requiring six degrees of freedom Has come.

Therefore, it is necessary to design a ball driving robot that can reduce the number of parts and reduce the height of the robot, improve the balancing stability of the robot, and realize 6 degrees of freedom.

Korean Patent Registration No. 10-0886113

SUMMARY OF THE INVENTION It is an object of the present invention to provide a structure of a ball driving robot for stably supporting a ball without providing a ball arrestor.

It is another object of the present invention to improve balancing stability of a ball driving robot.

It is another object of the present invention to provide a ball drive robot having six degrees of freedom.

It is another object of the present invention to provide a structure of an omni-wheel which increases the toughness against a road surface impact.

 The present invention relates to a spherical body constituting a robot body; A first table surrounding the sphere and spaced apart from the sphere and installed in a horizontal direction; A first motor provided on the first table and providing rotational force to the omni wheel; An omni wheel coupled to a shaft of a first motor unit formed in a vertical direction and installed to rotate while being in contact with the sphere in a horizontal direction; A second table disposed on the sphere; A first support coupled to the first table at one end and coupled to the second table at the other end; A control unit for controlling the first motor unit; A battery for supplying power to the first motor unit and the control unit; A third table disposed above the second table; A second support coupled to the second table at one end and coupled to the third table at the other end; Wherein a straight line connecting a contact point between the omni wheel and the sphere and a center point of the sphere is perpendicular to the rotation axis of the omni wheel and is greater than 0 degrees, And the angle of the ball is set to be an angle.

Further, the present invention may further comprise a second motor part for providing a rotational force to the parallel mechanism, wherein the parallel mechanism comprises a pair of revolute joints and a spherical joint, , And three sets of parallel mechanisms are formed on the third table.

The parallel mechanism of the present invention may further include: a first rotary joint coupled to a shaft of the second motor unit and rotating about an axis of the second motor unit; A second rotary joint coupled to the first rotary joint and rotating about a point where the first rotary joint is engaged with the first rotary joint; A spherical joint coupled to the second rotating joint; And a platform coupled to and moving with the spherical joint.

Further, the present invention may further include a third motor part for providing a rotational force to the parallel mechanism, wherein the parallel mechanism includes a rotary joint, a prismatic joint, and a pair of spherical joints And three sets of parallel mechanisms are formed on the third table.

In the parallel mechanism of the present invention, the rotary joint is a hinge shaft having one end fixed to the second table or the third table and having a hollow portion, and the linear joint includes a linear portion sliding in the longitudinal direction of the hinge shaft, Wherein the third motor unit is fixed within the hinge shaft to provide power for linear motion of the linear actuator, the spherical joint being coupled to one end of the linear actuator, ; ≪ / RTI >

The ball driving robot according to the present invention has an effect of stably supporting the ball without using the ball arrestor.

Further, the ball driving robot according to the present invention has an effect of improving balancing stability.

Further, the ball driving robot according to the present invention has an effect of providing 6 degrees of freedom.

In addition, the ball driving robot according to the present invention has an effect of increasing the robustness against the road surface impact by blocking vertical impact force transmitted from the ground surface from being applied directly to the omnis wheel which is the driving force transmitting means.

The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG.

1 is a perspective view of a conventional ball driving robot.
2 is a perspective view of a ball drive robot according to the present invention.
3 is a view showing a bottom structure of a ball driving robot according to the present invention.
4 is a view for explaining the degree of freedom of a sphere according to the present invention.
5 is a perspective view of an omni wheel according to the present invention.
6 is a cross-sectional view of an omni-wheel according to the present invention cut on the basis of AA in Fig.
7 is a view showing a state in which the omni-wheel according to the related art is in contact with the sphere.
8 is a sectional view of the omni wheel according to the present invention in contact with the sphere.
9 is a view showing an upper structure of a ball driving robot according to an embodiment of the present invention.
10 is a view for explaining degrees of freedom of a parallel mechanism according to an embodiment of the present invention.
11 is a view showing an upper structure of a ball driving robot according to another embodiment of the present invention.
12 is a view for explaining the degree of freedom of the parallel mechanism according to another embodiment of the present invention.

Hereinafter, various embodiments of the present document will be described with reference to the accompanying drawings. It should be understood, however, that the techniques described herein are not intended to be limited to any particular embodiment, but rather include various modifications, equivalents, and / or alternatives of the embodiments of this document. In connection with the description of the drawings, like reference numerals may be used for similar components.

Also, the terms "first," "second," and the like used in the present document can be used to denote various components in any order and / or importance, and to distinguish one component from another But is not limited to those components. For example, 'first part' and 'second part' may represent different parts, regardless of order or importance. For example, without departing from the scope of the rights described in this document, the first component can be named as the second component, and similarly the second component can also be named as the first component.

It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the other embodiments. The singular expressions may include plural expressions unless the context clearly dictates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the art. The general predefined terms used in this document may be interpreted in the same or similar sense as the contextual meanings of the related art and, unless expressly defined in this document, include ideally or excessively formal meanings . In some cases, even the terms defined in this document can not be construed as excluding the embodiments of this document.

FIG. 2 is a perspective view of a ball driving robot 1000 according to the present invention, and FIG. 3 is a view showing a bottom structure of a ball driving robot 1000 according to the present invention.

Will be described with reference to Figs. 2 and 3. Fig.

A ball driving robot 1000 is provided with a ball 100 serving as a wheel at a lower portion thereof. The ball 100 is formed of a material that is lightweight and has sufficient rigidity to meet the running performance while supporting the load of the ball driving robot 1000 as a body of the robot. In order to reduce the weight of the sphere 100, the sphere 100 has a hollow portion formed therein.

Also, in order to satisfy damping characteristics against friction and vibration generated in the rolling operation, the surface of the sphere 100 is preferably formed of a polyurethane material.

The first table 200 is formed at a lower height than the center of the sphere 100. The first table 200 is installed so as to be spaced apart from the sphere 100 while horizontally surrounding the sphere 100 so that interference does not occur when the sphere 100 moves.

The first motor unit 210 transmits power to the ball 100. The first motor unit 210 is installed at an upper portion of the first table 200 and transmits rotational force to the ball 100 through the omni wheel 220.

The omni wheel 220 transmits the rotational force transmitted from the first motor unit 210 to the ball 100 to move the ball driving robot 1000.

The omni wheel 220 is coupled to the shaft of the first motor unit 210. The first motor unit 210 is mounted on an upper portion of the first table 200 formed at a lower height than the center of the sphere 100. Accordingly, the length of the axis of the first motor coupled with the omni wheel 220 is relatively short as compared with the conventional ball-driven robot having the omni wheel 220 disposed on the sphere as shown in Fig. As a result, the power of the first motor unit 210 can be stably transmitted to the omni wheel 220 as the shaft length of the first motor unit becomes shorter, and the vibration problem or the like caused by the increase of the shaft length of the motor unit can be prevented have.

Since the ball driving robot 1000 is supported by one sphere 100 with respect to the ground, balancing stability is important in terms of the motion performance of the robot.

The ball drive robot 1000 according to the present invention may have a first motor unit 210, a first table 200 and an omni wheel 220 disposed at a lower portion of the ball 100 to lower the center of gravity of the robot . Thus, the balancing stability of the robot can be greatly improved, and the motion performance of the robot can be improved.

The second table 300 is disposed above the sphere 100. The second table 300 is installed apart from the ball 100.

A first support 310 is provided to support the second table 300. One end of the first support table 310 is coupled to the first table 200 and the other end is coupled to the lower portion of the second table 300. A plurality of first support rods 310 may be formed. The first supports 310 are spaced apart from each other at equal intervals. Preferably, the first supports 310 are spaced at a 120 degree angle and three may be disposed.

A ball caster 320 is coupled to a lower portion of the second table 300. The ball caster 320 serves to support the ball 100 in a downward direction. The downward support force of the ball caster 320 supporting the ball 100 is such that the omni wheel disposed at the lower portion of the ball 100 stably supports the ball 100 together with the horizontal supporting force acting on the ball 100 .

When the ball 100 is subjected to a vertical impact by the protrusion while moving on the ground, the ball caster 320 supports the vertical impact force. As shown in FIG. 1, in the conventional ball driving robot, the omni wheel is in contact with the sphere at an inclination angle, and the omnidirectional wheel is directly received by the vertical impact force transmitted from the ground. However, the ball driving robot 1000 according to the present invention increases the robustness against the road surface impact by preventing the vertical impact force transmitted from the ground from being transmitted directly to the omni wheel 220 as the driving force transmitting means.

4 is a view for explaining the degrees of freedom of the ball 100 according to the present invention.

4, the ball 100 is rotated by three omni wheels 220 disposed on the periphery of the ball 100 in a horizontal direction while being supported by a ball caster 320 at an upper portion thereof. .

The sphere 100 to which rotational force is transmitted by the omnidirectional wheel 220 is capable of parallel movement in two directions on a plane and rotational motion in a direction perpendicular to the plane. As a result, the sphere 100 is given three degrees of freedom.

FIG. 5 is a perspective view of the omni wheel 220 according to the present invention, FIG. 6 is a sectional view of the omni wheel 220 according to the present invention cut on the basis of AA in FIG. 5, 8 is a sectional view of the omni wheel 220 according to the present invention in contact with the sphere 100. As shown in Fig.

5 to 8, the omni wheel 220 according to the present invention includes an omni-wheel body 221, a first roller 223, and a second roller 225. [

The omni-wheel body 221 is disposed at the center of the omni-wheel 220, and a hollow shaft to which the shaft of the first motor unit 210 is coupled is formed.

A plurality of first rollers 223 are coupled at predetermined intervals along the circumferential direction of the omni-wheel body 221 and rotate in a direction perpendicular to the rotation direction of the shaft of the first motor unit 210.

The second roller 225 is coupled between two adjacent first rollers 223 along the circumferential direction of the omni wheel body 221 and rotates in a direction perpendicular to the rotational direction of the axis of the first motor part 210. [ do. The second roller 225 is formed to have a smaller diameter than the first roller 223.

As shown in FIG. 8, the omni-wheel 220 having the above-described structure is horizontally disposed at a lower portion of the sphere 100. The plurality of omni wheels 220 are spaced apart from each other by a predetermined distance.

The contact point B at which the first roller 223 or the second roller 225 contacts the ball 100 is smaller than the center of the circular cross section perpendicular to the longitudinal direction of the first roller 223 or the second roller 225 .

The angle formed by the straight line connecting the contact point B of the omni wheel and the center point C of the sphere to the vertical plane Y relative to the omni wheel rotational axis is approximately 30 degrees.

5, a contact path P connecting the contact points is shown.

7, when the omnidirectional wheel 220 is rotated in an oblique direction with respect to the upper part of the sphere 100, And transmits the rotation in the direction perpendicular to the paper surface simultaneously.

However, as shown in FIG. 8, in the case of the omni wheel 220 according to the present invention, since the omni wheel 220 is disposed in the horizontal direction and the rotation of the omni wheel 220 transmits only the rotation in the direction perpendicular to the ground The rotation of the first roller 223 and the second roller 225 plays a greater role than the conventional ball driving robot when the ball 100 moves.

As a result, the omni wheel 220 of the present invention rotates the first roller 223 and the second roller 225 more frequently than the previous omni wheel 220, thereby causing the wheel to wear uniformly . That is, the abrasion in the longitudinal direction of the first and second rollers 225 and the abrasion in a direction perpendicular to the abrasion are uniformly performed, thereby exhibiting improved wear characteristics.

FIG. 9 is a view illustrating an upper structure of a ball driving robot according to an embodiment of the present invention, and FIG. 11 is a diagram illustrating an upper structure of a ball driving robot according to another embodiment of the present invention.

Referring to FIG. 9, the ball driving robot 1000 according to the present invention is provided with a control unit 400 for controlling the first motor unit 210 and a second motor unit 620 to be described later.

The control unit 400 calculates the optimum rotational speed of the three first motor units 210 and provides them to the first motor unit 210 so that the ball 100 can realize three degrees of freedom motion.

Because of the characteristics of the mobile robot, a battery 500 for power supply is provided.

The controller 400 and the battery 500 are installed on the second table 300. This is for dispersing and disposing loads on the third table 600 on which the parallel mechanism 630 to be described later is mounted and the first table 200 on which the first motor unit 210 is installed. This prevents locally excessive loads from being added to each table and reduces the design burden on each table.

A third table 600 is disposed above the second table 300. It is preferable that the area of the third table 600 is smaller than the area of the second table 300 to improve balancing stability.

A second support table 610 is provided to support the third table 600. One end of the second support table 610 is coupled to the second table 300 and the other end is coupled to the lower portion of the third table 600. The second supports 610 may be formed in the same number and arrangement as the first supports 310.

The ball driving robot 1000 according to the present invention includes a parallel mechanism 630 formed on an upper portion of a third table 600 and a second motor portion 620 providing rotational force to the parallel mechanism 630 in order to realize six degrees of freedom, Or a third motor unit (not shown) is provided.

However, depending on the circumstances, the parallel mechanism 630, the second motor unit 620, and the third motor unit may be formed on the upper portion of the second table 300.

The parallel mechanism 630 may be formed as a set of two revolute joints 631 and one spherical joint 634 or one rotating joint 634 and one linear joint 634, A pair of prismatic joints 636 and a single spherical joint 637 and three pairs of parallel mechanisms 630 are preferably formed on the second table 300 or the third table 600.

Referring to Fig. 9, the coupling relationship in the case where the parallel mechanism 630 forms a pair of two rotary joints 631 (revolute joint) and one spherical joint 637 (spherical joint) will be described.

The first rotary joint 633 is coupled to the shaft of the second motor unit 620 and rotates about the axis of the second motor unit 620.

The second rotary joint 635 is coupled to the first rotary joint 633 and rotates around a point where it is engaged with the first rotary joint 633.

And a platform 640 is coupled to the plurality of spherical joints 637. The spherical joint 637 is coupled to the second rotary joint 635 to rotate in the forward direction.

11, when the parallel mechanism 630 forms a set of one rotating joint 634 and one linear joint 636 (Prismatic joint) and one spherical joint 637, .

The rotary joint 634 is a hinge shaft having a hollow portion with one end fixed to the second table or the third table and rotating.

The linear joint 636 is a linear actuator that slides the inside of the hinge shaft in the longitudinal direction of the hinge shaft.

The third motor part (not shown) is fixed inside the hinge shaft to provide power for linear motion of the linear actuator, and the spherical joint 637 is coupled to one end of the linear actuator.

The platform 640 is coupled to the plurality of spherical joints 637.

FIG. 10 is a view for explaining the degree of freedom of the parallel mechanism 630 according to an embodiment of the present invention, and FIG. 12 is a view for explaining degrees of freedom of the parallel mechanism according to another embodiment of the present invention.

10 and 12, the platform 640 is provided with a rotational motion in two directions and a linear motion in a direction perpendicular to the third table 600 through the parallel mechanism 630 according to the present invention . Eventually, the platform 640 moves with three degrees of freedom.

The third table 600 is coupled to a first table 200 that moves in three degrees of freedom and the platform 640 is moved in three degrees of freedom with respect to the third table 600 by the parallel mechanism 630, So that the platform 640 can move in six degrees of freedom.

The control unit 400 calculates an optimum rotational speed for the three second motor units 620 or the third motor unit to operate the platform 640 in a desired motion mode and outputs it to each of the second motor units 620 ) Or the third motor section.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the invention as defined by the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

Bore Leicester 10
Ball drive robot 1000
District 100
The first table 200
The first motor unit 210
Omni Wheel 220
Omni Wheel Body 221
The first roller 223
The second roller 225
The second table 300
The first support block 310
Ballcaster 320
The control unit 400
Battery 500
The third table 600
The second support 610
The second motor section 620
Parallel mechanism 630
Rotary joints 631, 634
The first rotary joint 633
The second rotary joint 635
Straight Joint 636
Spherical Joints 637
Platform 640
Contact point B
Center point of the sphere C
Contact path P
The axis of rotation of the omni wheel X
Vertical plane Y against the axis of rotation of the omni wheel

Claims (5)

Spheres constituting the robot body;
A first table surrounding the sphere and spaced apart from the sphere and installed in a horizontal direction;
A first motor provided on the first table and providing rotational force to the omni wheel;
An omni wheel coupled to a shaft of the first motor unit formed in a vertical direction and installed to rotate while contacting the sphere in a horizontal direction;
A second table disposed on the sphere;
A first support coupled to the first table at one end and coupled to the second table at the other end;
A control unit for controlling the first motor unit;
A battery for supplying power to the first motor unit and the control unit;
A third table disposed above the second table;
A second support coupled to the second table at one end and coupled to the third table at the other end;
And a parallel mechanism formed on the second table or the third table,
And a straight line connecting a contact point between the omni wheel and the sphere and a center point of the sphere forms an angle larger than zero degrees with a plane perpendicular to the rotation axis of the omni wheel. The method according to claim 1,
And a second motor portion for providing rotational force to the parallel mechanism,
The parallel mechanism forms a set of two revolute joints and one spherical joint,
And a third set of parallel mechanisms are formed on the second table or the third table, 3. The method of claim 2,
The parallel mechanism includes:
A first rotary joint coupled to a shaft of the second motor unit and rotating about the second motor sub-shaft;
A second rotary joint coupled to the first rotary joint and rotating about a point where the first rotary joint is engaged with the first rotary joint;
A spherical joint coupled to the second rotating joint; And
And a platform coupled to the spherical joint for movement. The method according to claim 1,
And a third motor portion for providing power to the parallel mechanism,
The parallel mechanism forms a set of one rotating joint, one prismatic joint and one spherical joint,
And a third set of parallel mechanisms are formed on the second table or the third table, 5. The method of claim 4,
Wherein the rotary joint is a hinge shaft having one end fixed to the second table or the third table and having a hollow portion,
Wherein the linear joint is a linear actuator that slides the inside of the hinge shaft in the longitudinal direction of the hinge shaft,
The third motor part is fixed inside the hinge shaft to provide power for the linear actuator to linearly move,
Wherein the spherical joint is coupled to one end of the linear actuator,
And a platform coupled to the spherical joint for movement.

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