KR100458284B1 - 4-bar passive linkage-type locomotive mechanism of six-wheeled mobile robot capable of climbing up stairs - Google Patents

Abstract

The present invention relates to a four-section link mechanism driving system of a six-wheeled traveling robot capable of climbing a staircase. The present invention relates to a system for performing a stair climbing function by adding a four-section link mechanism to a robot having six wheels. Three wheels, each of which are independently driven on both sides of the robot, are connected to the body using three links and a rotary joint, and the six wheels are connected using a joint mechanism that connects the body and the first link and restricts the rotation angle of the first link. It is possible to climb the rugged terrain such as staircase inside and outside in the wheel type mobile robot by constructing the four-link linkage driving system of the driving robot, and the structure is simple and the control is unnecessary because the active control is not necessary. It provides excellent driving mechanism of wheel type mobile robot.

Description

4-bar passive linkage-type locomotive mechanism of six-wheeled mobile robot capable of climbing up stairs}

The present invention relates to a four-section link mechanism traveling system of a six-wheeled traveling robot capable of climbing a staircase, and a system for performing a stair climbing function by adding a four-section link mechanism to a robot having six wheels.

The driving robot with the climbing function of the stairs can be used as a mobile robot for service robots with unmanned monitoring inside buildings, nuclear reactor inspection of nuclear power plants, grasping the fire situation, and housekeeping at home.

The driving mechanisms of the mobile robots developed so far are divided into three categories such as wheeled, tracked, and legged.

Among the mobile robots, the track type is the driving mechanism of the mobile robot capable of climbing the stairs, because the driving mechanism can be easily achieved without considering the distance between the wheels.

Conventionally, in the case of a wheeled mobile robot, there is little invention about the wheel-type mobile robot because of the fixed distance between the driving wheels, and because of the inability to adapt to a terrain such as a staircase, the current adds a stair climbing capability to the wheeled mobile robot. One invention exists.

At present, the driving mechanism that can control the distance between the wheels of the wheeled mobile robot is improved by improving the climbing ability of the stairs. However, most of them are applied to the wheeled mobile robot by applying active mechanical elements and applying complex driving mechanisms. Stair climbing ability is given. In other words, in the case of a wheel-type mobile robot, the stairs need to be heavily weighted by complicated driving mechanisms or active mechanical elements, and have complicated control systems.

In the case of multi-legged mobile robot, the adaptability to the terrain is excellent when climbing stairs. There is a disadvantage that the driving mechanism is complicated and difficult to control.

The present invention has been invented to solve the above problems, the object of the present invention is to climb the rugged terrain, such as stairs indoors and outdoors, the structure is simple, the control is simple, the wheel type movement excellent in energy efficiency when driving To provide a driving mechanism of the robot.

In order to achieve the above object, the three wheels each independently driven on both sides of the robot having a left-right symmetrical structure is connected to the body by using three links and rotation joints, and the body and the first link is connected, It is to provide a section 4 link mechanism driving system of a climbing ladder capable of climbing a stair climbing 6-wheel robot, which is characterized by constructing a section 4 link mechanism driving system of a 6-wheel driving robot using a joint mechanism for limiting the rotation angle.

1 is a view of an embodiment of a four-section link mechanism driving system of the present inventors climbable six-wheeled traveling robot.

Figures 2a, 2b, 2c is a view of the structure of the rotation angle limitable rotary joint mechanism of the four-link linkage driving system of the present inventors climbable six-wheel drive robot.

Figures 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, 3i, 3j, 3k, 3l is a four-section link mechanism of the present invention climbing stairs six wheel robot An illustration of stair climbing through an embodiment of a traveling system.

Figure 4 is a view of yet another embodiment of a four-section link mechanism driving system of the present inventors climbing climbing six-wheel robot.

Figure 5 is a view of another embodiment of a four-section link mechanism driving system of the present inventors climbable six-wheel drive robot.

Figure 6 is a view of another embodiment of the four-link linkage driving system of the present inventors climbable six-wheel drive robot.

7 is a view showing another embodiment of a four-section link mechanism driving system of the present inventors climbable six-wheel drive robot.

<Description of main parts of drawing>

1: first link 2: second link

3: third link 4: body

5: fourth link

31, 32, 33, 34, 35: rotary joint

40: pin-slot joint mechanism

50: rotary joint mechanism with limited rotation angle

51: body side disc joint part 52: link side disc joint part

53: axis of rotation

60: spring-damper mechanical element

70: active mechanical elements

100: first wheel 200: second wheel

300: third wheel

1 is a view showing an embodiment of a four-section link mechanism driving system of the present inventors climbing climbing 6-wheel robot, Figures 2a, 2b, 2c is a four-section link mechanism of the present inventors climbing climbing climbing six-wheel robot 3A, 3B, 3C, 3D, 3E, 3F, 3G, 3H, 3I, 3J, and 3K, which are views of the structure of the rotation joint mechanism capable of limiting the rotation angle of the driving system. Figure 3l is an exemplary view of the stair climbing through the embodiment of the four-stage link mechanism running system of the present inventors climbable six-wheel drive robot, Figure 4 is a four-section link mechanism driving system of the present inventors climbable six-wheel drive robot Figure 5 is a view of another embodiment of Figure 5 is a view of another embodiment of the four-stage link mechanism driving system of the present inventors climbable climbing 6-wheeled robot, Figure 6 is a present invention climbing stairs capable of climbing six-wheel Section 4 linkage mechanism of robot A view of yet another embodiment of the system, Figure 7 is a diagram of yet another embodiment of the four-bar linkage mechanism driving system, the inventors of climbing stairs possible wheel 6 traveling robot.

Hereinafter, the right part of the driving robot will be described to replace the entire part. That is, the wheel-type traveling system described below has a left side surface which is symmetrical with the right side.

A schematic diagram of an embodiment of a movement mechanism of a six-wheeled traveling robot invented to impart a stair climbing function is shown in FIG. 1. The configuration of the six-wheeled traveling robot has six driving sources (wheels) of three on each side of the traveling robot, as shown in FIG. 1, and these driving sources are driven independently of each other. And the three wheels (100.200, 300) of the side (right side when viewed from the front) of the traveling robot is connected to the traveling robot body (4) by three links (1, 2, 3). The first link 1, the second link 2, and the third link 3 shown in FIG. 1 are connected to the body 4 of the traveling robot to form a mechanism of a four-section link mechanism having one degree of freedom. Referring to the connection of the body 4 and the three links, the first link 1 connects the first wheel 100 and the second wheel 200 of the traveling robot to each other and the first link to the body of the traveling robot. It is connected to the robot body 4 by a joint mechanism 50 (to be described later) that limits the relative rotation angle of (1). In addition, one end of the second link 2 is connected to the third wheel 300 of the traveling robot and the other end is connected to the first link 1 by the rotary joint 31. The other third link 3 is connected to the middle of the second link 2 by one end of the rotary joint 32 and the other end of the body 1 of the traveling robot by the rotary joint 33. Connected with

The joint mechanism 50 will be described. A schematic view of the joint mechanism is shown in FIG. 2A, where the joint mechanism 50 serves to limit the relative rotation angle between the body 4 of the traveling robot and the first link 1. Through this joint mechanism, it is designed to be able to climb stairs without applying any active mechanical elements to the section 4 link mechanism robot. The proposed joint mechanism 50 having a shape similar to that of the clutch, which is a power transmission machine element, rotates about the projection of the body side disc joint part 51 attached to the robot body 4 and the rotation shaft 53 connected to the body. The relative rotation of the first link 1 with respect to the body 4 of the robot is limited depending on the presence or absence of contact between the protrusions of the link-side disc joint part 52 attached to the first link 1. The relative allowable rotational angle of the first link 1 relative to the robot body 4 is determined according to the shape and position of the projections of the joint parts 51 and 52.

2b shows the position between the projections of the disc joint parts 51 and 52 during the movement in which the first link 1 rotates counterclockwise with respect to the body 4 of the traveling robot. The rotational movement of the first link 1 with respect to the body 4 of the traveling robot is limited at the moment of contact between the protrusion of the link side disc joint part 52 and the protrusion of the body side disc joint part 51. Therefore, the maximum rotation angle in the anticlockwise direction of the first link 1 is determined by the rotation angle up to the moment when the contact between the projections occurs.

FIG. 2C shows the position between the projections of the disc joint parts 51 and 52 during the movement in which the first link 1 rotates clockwise with respect to the body 4 of the traveling robot. The rotational movement of the first link 1 with respect to the body 4 of the traveling robot is also limited at the moment when contact occurs between the projection of the link side disc joint component 52 and the projection of the body side cylindrical joint component 51. The maximum allowable clockwise rotational angle of the first link 1 is thus determined by the rotational angle up to the moment when contact between the projections occurs.

The angle of rotation using the disc joint components is determined by local information on which the robot will be used.

Now, I will explain the climbing of the 6 wheel 4 link mechanism robot.

FIG. 3 is a view illustrating a stair climbing state of a six-wheel drive robot employing the section 4 moving mechanism described in FIG. 1 and the joint mechanism shown in FIG. 2. When the first wheel 100 of the traveling robot equipped with the driving mechanism proposed as shown in FIG. 3A comes into contact with the wall surface of the stairs, the kinematic characteristics of the four-section link mechanism as shown in FIG. One link (1) is to rotate in a counterclockwise direction with respect to the body (4) of the robot. The first wheel 100 rotates to the maximum allowable rotation angle in the counterclockwise direction as shown in FIG. 2B while the first wheel 100 maintains contact with the ground surface of the stairs and the second wheel 200. Will be Thus, since the second wheel 200 is a step climbing while maintaining contact with the ground, the traction force by the friction between the second wheel 200 and the ground serves to improve the climbing performance of the proposed robot.

In the state where the first link 1 is rotated to the maximum rotation angle counterclockwise with respect to the body 4 of the robot, the degree of freedom of the linkage mechanism of the four sections becomes zero, and the rigid body is moved. The wall surface and the third wheel (300) reaches the state shown in Fig. 3d via Fig. 3c while maintaining contact with the ground.

In FIG. 3d, the second wheel 200 makes contact with the wall surface of the stairs and the frictional force causes the first link 1 to rotate clockwise with respect to the body 4 of the robot, as shown in FIG. 3e. Will be reached.

In the state of FIG. 3E, the first wheel 100 maintains contact with the wall surface of the stairs and the third wheel 300, and the first link 1 maintains contact with the bottom surface of the stairs. 4) Rotate the counter clockwise to the maximum allowable angle of rotation. In the state rotated to the counterclockwise allowable maximum angle of rotation, the proposed four-section link mechanism is in a rigid motion again, the first wheel 100 is to climb the wall of the stairs. When the third wheel 300 comes into contact with the wall surface of the stairs, the first link 1 rotates counterclockwise with respect to the robot body 4 due to the kinematic characteristics of the four-section link mechanism. 200 comes into contact with the bottom surface of the stairs and the first wheel 100 loses contact with the stairs to reach the state shown in FIG. 3F.

In the stair climbing state of the traveling robot shown in FIG. 3F, the kinematics of the link mechanism driving mechanism of the fourth section is maintained while the second wheel 200 maintains contact with the floor surface of the stairs and the third wheel 300. Due to the characteristics, the first link 1 makes a counterclockwise rotational movement with respect to the robot body 4 such that the third wheel 300 climbs the wall surface of the stairs. This movement is a step in FIG. 3g where the first wheel 100 comes into contact with the floor surface of the stairway with the first link 1 rotated to a counterclockwise permissible maximum rotation angle with respect to the robot body 4. Climbing status is reached.

In the stair climbing state shown in FIG. 3G, the proposed four-section link mechanism performs rigid body movement, and the third wheel 300 continues to climb the wall of the stairs, and the second wheel 200 eventually comes into contact with the wall of the stairs. The stair climbing state of FIG. 3H is reached. In this state, it is necessary to properly design the four-section link mechanism proposed that the second wheel 200 and the third wheel 300 of the driving robot do not come into contact with the wall surface of the stairs at the same time.

In the step climbing state of FIG. 3H, the first link 1 performs a clockwise rotational movement with respect to the robot body 4 by the frictional force of the first wheel 100, and the second wheel 200 moves the wall surface of the stairs. The third wheel 300 reaches the state of FIG. 3I which is in contact with the bottom surface of the stairs.

In the step climbing state shown in FIG. 3i, the first link 1 rotates counterclockwise with respect to the robot body 4 by the frictional force with the wall of the step of the second wheel 200. Climbs the wall of the stairs and eventually reaches the climbing state shown in FIG.

In the stair climbing state of FIG. 3J, the proposed four-section link mechanism maintains the state, leading to the step of FIG. 3K in which the third wheel 300 comes into contact with the wall surface of the stairs.

In the step climbing state of the driving robot of FIG. 3K, the second link 2 rotates clockwise with respect to the first link 1 by the frictional force with the stairs wall of the third wheel 300. 300 is to climb the wall of the stairs to reach the climbing state of the running robot shown in Figure 3l.

When the proposed driving robot climbs the stairs, the stair climbing state shown in FIG. 3 is repeatedly performed.

The same effect can be achieved through the other embodiments as well as the embodiment shown in FIG. 1, and are illustrated in FIGS. 4, 5, 6, and 7.

First, the embodiment shown in FIG. 4 will be described. FIG. 4, unlike FIG. 1, has a common rotary joint 34 in place of the joint mechanism 50 and pin-slots to limit the rotation angle of the first link 1, which is a function of the joint mechanism 50 in FIG. 1. The joint mechanism 40 and the fourth link 5 are coupled to limit the rotation angle of the first link 1. As shown in FIG. 4, the fourth link 5 is connected at one end to the second link 2 by a rotary joint 35, and the other end of the fourth link 5 is provided with a pin-slot mechanism. ) And fixedly coupled.

Through the above configuration, the section 4 link mechanism driving mechanism enables one degree of freedom. This one degree of freedom motion enables the relative motion of each driving wheel of the traveling robot and the body of the robot, thereby improving the adaptability of the robot to the terrain. However, excessive rotation between the driving wheels 100, 200, 300 and the body 4 when climbing the stairs causes the driving wheels 100, 200, 300 to simultaneously contact the stairs walls. In this state, the stair climbing should be performed only by the friction force between the driving wheels 100, 200, and the stairs. The joint mechanism 50 functions to limit excessive rotation between the first link 1 and the robot body so that such a state does not occur. The pin-slot joint mechanism 40 is added between the body 4 of the traveling robot and the first link 1 and the second link 2 constituting the section 4 link mechanism driving mechanism. It can replace the functional effect of the joint mechanism 50 of. The pin-slot joint mechanism 40 is a joint mechanism that allows two degrees of freedom between the first link 1 and the second link 2 to allow relative rotational and translational movement between the joints 34 and 35. Let's do it. By adjusting the length of the slot of the pin-slot joint, the allowable relative rotation angle between the body 4 of the traveling robot and the first link 1 can be adjusted.

The pin-slot joint mechanism is described in detail so that the pins can reciprocate in the slots, so the length of the pin-slot joint mechanism varies depending on the position of the pin. By using this, the allowable relative rotation angle between the body 4 and the first link 1 of the traveling robot is adjusted.

With the same effect as described above, the four-section link mechanism of FIG. 4 can also climb stairs like FIG.

Referring to the embodiment shown in FIG. 5, unlike the embodiment in FIG. 1, the four-section link mechanism driving mechanism lowering the position of the rotary joints 33 and 34 of the body of the robot than the radius of the wheel without using a joint mechanism. It consists of:

That is, one end of the first link 1 is connected to the second drive wheel 200, and the other end is connected to the second link 2 and the rotary joint 31. One end of the second link (2) is connected to the third drive wheel (300) and the other end is divided into two branches as shown in Figure 5 one side of the first driving wheel 100 and the other side of the rotary joint It is connected to the body by 34. One end of the third link 3 is connected by the second link and the rotary joint 32 and the other is connected by the body and the rotary joint 33.

As shown in FIG. 5, it is a feature of this embodiment that the rotary joint to which the link and the body are connected is below the center of rotation of the wheel. This applies the concept of rotation center. Section 4 link mechanism Lowering the center of rotation of the body of the drive robot than the drive shaft of the drive wheel of the traveling robot, when the traveling robot comes in contact with an obstacle such as a wall of the stairs, the first link (1) constituting the link mechanism driving mechanism The robot body 4 automatically rotates in a counterclockwise direction so that all the driving wheels 100, 200, and 300 of the traveling robot maintain contact with the ground at the same time, thereby improving the traction force of the traveling robot. In order to maintain this effect, the section 4 link mechanism driving mechanism is kinematically configured to position the center of rotation of the traveling robot body lower than the driving shaft as possible.

Referring to the embodiment shown in FIG. 6, the difference from the case of FIG. 1 is that instead of using a joint mechanism, an active mechanical element 70 is used. That is, an active mechanical element consisting of a motor and a braking device is installed in the joint mechanism, and the rest is as described in FIG.

The reason for constructing the embodiment shown in FIG. 6 is that in order for the wheeled driving robot to climb an obstacle such as a staircase, the front driving wheel 100 of the driving robot ultimately must climb over an obstacle such as a stair and is active such as a motor. This is because the mechanical element 70 can be added between the body 4 of the traveling robot and the first link 1 to actively control such movement. The driving characteristics of the traveling mechanism of FIGS. 3A to 3L may be artificially generated using active control.

The embodiment shown in FIG. 7 is an embodiment complementing the embodiment shown in FIG. That is, the spring-damper mechanism 60 is attached between the first link 1 and the second link 2 by using the rotary joints 34 and 35 to provide a cushioning effect and a flexible movement. The spring-damper mechanism is not only attachable in the case of FIG. 1, and although not shown, a rotation joint is used between the first link 1 and the second link 2 in FIGS. 4, 5, and 6. Can be attached, and the same effect as described above can be obtained.

In addition, the spring-damper mechanism 60 may be used as long as it is composed of pure spring alone or any other buffering configuration.

As described above, the three wheels that are independently driven are connected to the body using three links and rotation joints, and the body and the first link are connected to each other, and the six wheels using a joint mechanism restricting the rotation angle of the first link. It is possible to climb the rugged terrain such as stairs inside and outside in the wheel type mobile robot by constructing the four-link linkage driving system of the driving robot, and the structure is simple, the control is simple, and the wheel type mobile robot with excellent energy efficiency when driving. It provides a driving mechanism.

Kinematic optimization method of the link structure to optimize the climbing performance of the driving robot according to the structure of the simple four-section link mechanism driving mechanism applicable to the stairs climbing wheel-type mobile robot obtained through the present invention and indoor and outdoor stairs is the future mobility And it can suggest useful analytical method in developing driving mechanism of mobile robot which requires high adaptability to terrain.

Claims (9)

In a wheel-type traveling robot having six driving wheels and a symmetrical structure, A first link connecting the first wheel to the second wheel and connected to the body by a joint mechanism, and connected to the second link by a rotation joint; A second link connected to the first link by a rotary joint, and connected to a third wheel at the other end thereof, and connected to the third link by a rotary joint; The linkage driving system of the four-stage climbing mechanism of the six-wheeled climbing ladder, characterized in that it comprises a third link is connected by the second link and the rotary joint, and the other end is connected to the body by the rotary joint. The method according to claim 1, The joint mechanism includes a four-sided link mechanism driving system of a climbing ladder capable of climbing a six-wheeled robot, characterized in that it includes a body side disc joint having a protrusion, a link side disc joint having a protrusion, and a rotating shaft. In a wheel-type traveling robot having six driving wheels and a symmetrical structure, A first wheel and a second wheel, connected to the body by a rotary joint mechanism, connected to the second link by a rotary joint, fixedly coupled to the fourth link, and having a pin-slot joint mechanism inside the link. 1 link; A second link connected to the first link by a rotation joint, the other end of which connects a third wheel, a third link by a rotation joint, and a fourth link by a rotation joint; A third link connected to the second link by a rotation joint and connected to the body by a rotation joint at the other end thereof; A four-stage link mechanism traveling system of a climbing ladder capable of climbing a six-wheeled robot comprising a fourth link fixedly coupled to the first link and connected by the second link and a rotary joint. In a wheel-type traveling robot having six driving wheels and a symmetrical structure, A first link connecting the second wheel and connected to the second link by a rotation joint; It is connected by the first link and the rotary joint, one end has a shape divided into two branches, one of the two branches is connected to the first wheel, the other branch is lower than the radius of the wheel by the rotary joint A second link connected to the body and connected to the third wheel at the other end and connected to the third link by a rotation joint; Section 4 of the six-wheeled climbing robot capable of climbing the stairs characterized in that it comprises a third link is connected by the second link and the rotary joint, the other end is connected to the body at a lower than the radius of the wheel by the rotary joint Link mechanism driving system In a wheel-type traveling robot having six driving wheels and a symmetrical structure, A first link connecting the first wheel to the second wheel, the first link connected to the body by an active mechanical element, and the second link connected to the second link by a rotary joint; A second link connected to the first link by a rotary joint, and connected to a third wheel at the other end thereof, and connected to the third link by a rotary joint; The linkage driving system of the four-stage climbing mechanism of the six-wheeled climbing ladder, characterized in that it comprises a third link is connected by the second link and the rotary joint, and the other end is connected to the body by the rotary joint. The method according to claim 5, The four-way link mechanism driving system of the six-wheel traveling robot capable of climbing stairs, characterized in that the active mechanical element includes a motor and a control device. The method according to any one of claims 1, 3, 4, and 5, The four-stage link mechanism driving system of the stair climbing possible six-wheeled traveling robot further comprising a shock absorber connected by a rotary joint between the first link and the second link. The method according to claim 7, The four-link linkage driving system of the stair climbing possible six-wheel drive robot, characterized in that the shock absorber is a spring-damper mechanism The method according to any one of claims 1, 3, 4, and 5, The four-wheel linkage driving system of the six-wheel climbing robot capable of climbing stairs, characterized in that the driving wheels are driven independently of each other