KR101688867B1 - Passive compliance gripper and variable passive compliance gripper with displacement measurement function - Google Patents

Passive compliance gripper and variable passive compliance gripper with displacement measurement function Download PDF

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Publication number
KR101688867B1
KR101688867B1 KR1020160039928A KR20160039928A KR101688867B1 KR 101688867 B1 KR101688867 B1 KR 101688867B1 KR 1020160039928 A KR1020160039928 A KR 1020160039928A KR 20160039928 A KR20160039928 A KR 20160039928A KR 101688867 B1 KR101688867 B1 KR 101688867B1
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KR
South Korea
Prior art keywords
gripper
displacement
stiffness
controller
variable
Prior art date
Application number
KR1020160039928A
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Korean (ko)
Inventor
박찬훈
김휘수
박동일
도현민
최태용
윤동원
경진호
손영수
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한국기계연구원
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Application filed by 한국기계연구원 filed Critical 한국기계연구원
Priority to KR1020160039928A priority Critical patent/KR101688867B1/en
Application granted granted Critical
Publication of KR101688867B1 publication Critical patent/KR101688867B1/en
Priority to US16/083,760 priority patent/US10987816B2/en
Priority to PCT/KR2017/003111 priority patent/WO2017171303A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J15/00—Gripping heads and other end effectors
    • B25J15/04—Gripping heads and other end effectors with provision for the remote detachment or exchange of the head or parts thereof
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J15/00—Gripping heads and other end effectors
    • B25J15/04—Gripping heads and other end effectors with provision for the remote detachment or exchange of the head or parts thereof
    • B25J15/0408—Connections means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J19/00—Accessories fitted to manipulators, e.g. for monitoring, for viewing; Safety devices combined with or specially adapted for use in connection with manipulators
    • B25J19/02—Sensing devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J9/00—Programme-controlled manipulators
    • B25J9/10—Programme-controlled manipulators characterised by positioning means for manipulator elements
    • B25J9/14—Programme-controlled manipulators characterised by positioning means for manipulator elements fluid
    • B25J9/144—Linear actuators
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
    • B25J9/00—Programme-controlled manipulators
    • B25J9/16—Programme controls
    • B25J9/1612—Programme controls characterised by the hand, wrist, grip control

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  • Engineering & Computer Science (AREA)
  • Robotics (AREA)
  • Mechanical Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Orthopedic Medicine & Surgery (AREA)
  • Manipulator (AREA)

Abstract

The present invention relates to a variable manual rigid gripper, and the manual rigid gripper capable of measuring displacement measuring displacement in accordance with deformation of the gripper when the gripper is assembled to control rigidity or correct a target moving path and a target position of a robot using the displacement. As such, the present invention properly handles an error of a position and a tolerance for processing a workpiece; easily teaches an assembling process; and improves an assembling speed and an assembling quality.

Description

[0001] The present invention relates to a passive compliance gripper and a variable passive compliance gripper,

The present invention overcomes the positional errors and machining tolerances that may occur between objects to be assembled in an assembling work environment by an automation device such as a robot, To a passive stiffness gripper and a variable passive stiffness gripper capable of performing displacement measurement.

Many parts of the production process are automated by robots, but assembly work is very difficult and automation by robots is difficult. That is, if the actual assembly target parts exactly coincide with the geometric information in the drawing, these assembly target parts are fixed at the correct position of the work table, and another part is correctly gripped at the correct position of the gripper of the robot, By ensuring that the position and posture are precisely controlled, the assembly operation of these two parts can be automated. However, in reality, since the parts to be assembled are different from the sizes of the drawings, there is an error in the fixed position, so that it is difficult to realize the assembly by only the position control of the robot.

As such, it is difficult to precisely perform the assembly operation by only the position control of the robot. Therefore, various assembly robots based on the force control based on the reaction force generated in the assembly operation are being studied.

However, in the assembly method based on the force control, a force sensor is installed at the end of the robot to measure the assembly reaction force acting at the time of assembly, and then the assembly operation is performed by controlling the movement of the entire robot to control the assembly reaction force. In this method, a very expensive 6-DOF force-moment sensor is required, and since the whole robot moves and performs assembly, the inertia is large (inertia of the robot rather than inertia of the gripper is large). In addition, since the active force control method is used, if there is an unexpected situation during the assembling operation, there is a possibility of divergence of the control algorithm and there is a disadvantage in terms of safety. In addition, there is a problem that it is very difficult to teach the assembling work because it is difficult to operate the robot so that the robot is positioned at the precise position necessary for assembling when the assembly work is first taught.

An additional manual compliance device (RCC-Remote Center Compliance) has been developed and utilized at the end of the robot to solve the problem of the assembly control method of the active force control method of the robot. Since the manual compliance device or the manual rigidity device ensures the compliance required for assembly even when the position of the robot is misaligned with respect to the position of the workpiece, the gripping force generated by the gripper and the workpiece, There is a great advantage that it is assembled without occurrence. However, there is a problem that the robot controller can not accurately know the actual position of the robot end because the displacement of the gripper end necessarily caused by the compliance can not be measured. This is a more serious problem because the controller does not know the deflection of the gripper end due to gravity, especially in the horizontal orientation (assembly in the direction perpendicular to gravity), which causes vertical orientation (assembly in the direction parallel to gravity) There is a problem in that it is possible. In other words, due to the compliance, the end displacement is naturally generated. Since the end displacement can not be measured, the robot controller can not cope with this problem. This is a great obstacle to the range of the manual compliance device, It becomes a stumbling block.

JP 1994-005828 (1994.01.25.)

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems as described above, and it is an object of the present invention to provide an apparatus and a method for assembling a vehicle, The resulting gripper displacement is measurable and its information is used during the assembly process. If necessary, the stiffness can be appropriately changed to effectively cope with various assembly situations, thereby improving the assembly speed and the quality of assembly. And to provide a measurable manual stiffness gripper and a variable manual stiffness gripper.

In order to accomplish the above object, the present invention provides a passive rigid gripper capable of measuring a displacement, comprising: a passive rigid part formed to be deformable on the other side in a state where one side is fixed; Displacement measuring means provided on the manual rigid portion and capable of measuring displacement according to deformation of the passive rigid portion; And a gripper mounting portion formed on the other side of the manual rigid portion and capable of mounting a gripper portion for gripping a component; And a control unit.

Further, the present invention is characterized by further comprising a gripper portion mounted on the gripper mounting portion.

The gripper controller may further include a displacement calculating unit that calculates a position of a lower end of the gripper unit based on the displacements measured by the displacement measuring unit, And the gripper controller can provide the target movement path and the target position of the robot to the robot controller according to the displacement of the lower end of the gripper part calculated by the displacement calculation part .

The variable passive rigidity gripper according to the present invention is a variable passive rigidity gripper capable of adjusting a rigidity formed between both sides so that the other side can be deformed in a state where one side is fixed, A variable stiffness device installed in the variable passive stiffness portion and capable of changing rigidity; Displacement measuring means provided in the variable passive stiffness portion and capable of measuring displacement according to deformation of the variable passive stiffness portion; And a gripper mounting portion formed on the other side of the variable passive stiffening portion and capable of being mounted with a gripper portion for gripping the component; And a control unit.

Further, the present invention is characterized by further comprising a gripper portion mounted on the gripper mounting portion.

The gripper controller may further include a gripper controller to which the variable stiffness device is connected, wherein the gripper controller includes a stiffness adjuster capable of adjusting the rigidity of the variable stiffness device.

The gripper controller further includes a displacement calculating unit that calculates a position of a lower end of the gripper unit based on the displacements measured by the displacement measuring unit. The gripper controller includes a displacement calculating unit, And a stiffness calculating unit connected to the stiffness adjusting unit. The stiffness calculating unit calculates the stiffness according to the position of the lower end of the gripper unit calculated by the displacement calculating unit, and controls the stiffness of the variable stiffness device through the stiffness adjusting unit .

The gripper controller is connected to a robot controller for controlling the movement path and position of the robot. The gripper controller controls the gripper controller to move the target movement path and the target position of the robot to the robot controller according to the displacement of the lower end of the gripper part, Can be provided.

The manual rigidity gripper and the variable manual rigidity gripper capable of measuring the displacement of the present invention can provide manual rigidity that can appropriately cope with positional errors and machining tolerances of a workpiece during assembly and can be applied to various assembling operations. It is possible to easily grasp the assembled state and to provide appropriate rigidity to each assembly environment and thus it can be applied to various assemblies such as vertical and horizontal directions.

In addition, unlike existing assembly systems that require expensive force control based robots, it is highly applicable to various robots such as position control based robots, and it is possible to construct an assembly system that is easy and quick without a separate complex force control algorithm have.

In addition, the present invention has an advantage of improving the assembling speed and assembling quality by correcting the path of the robot by providing the corrected assembling position to the robot so as to not only grasp the assembling state at the assembling work but also perform the assembling smoothly.

1 and 2 are conceptual diagrams of a manual rigidity gripper equipped with displacement measuring means capable of measuring the displacement of the gripper caused by an external force.
FIGS. 3 and 4 are conceptual diagrams of a variable manual stiffness gripper which can calculate the stiffness based on the displacement of the gripper caused by an external force, thereby giving a proper stiffness to the gripper.
5 is a perspective view showing a state where the manual rigid gripper or the variable manual rigidity gripper of the present invention is mounted on the arm of the robot.
6 and 7 are an assembled perspective view and an exploded perspective view of a variable passive rigidity gripper capable of displacement measurement according to a detailed embodiment of the present invention.
8 is an exploded perspective view of a Stewart platform according to the present invention;
9 and 10 are a perspective view and a front view showing a state where the Stewart platform and the balloon according to the present invention are assembled.
11 is a schematic view showing a displacement according to linear expansion and contraction of a leg according to the present invention;
12 and 13 are front views showing a state in which the first part is inserted and assembled into the insertion hole of the second part while the passive rigidity gripper capable of displacement measurement of the present invention is deformed.
14 to 17 are a perspective view and a front view showing a state in which the lower structure is deformed in a state where the upper structure according to the present invention is fixed.

Hereinafter, a manual rigidity gripper and a variable manual rigidity gripper capable of measuring displacement according to the present invention will be described in detail with reference to the accompanying drawings.

First, a manual stiffness gripper and a variable manual stiffness gripper 1000 capable of measuring the displacement of the present invention can be coupled to the arm 2100 end of the robot 2000 as shown in FIG. 5, ) To be moved to a desired position and inserted into a component to be assembled and assembled.

[Example 1]

1 and 2 are conceptual diagrams of a manual rigidity gripper equipped with displacement measuring means capable of measuring the displacement of the gripper caused by an external force.

As shown in the drawing, the manual rigid gripper 1000 capable of measuring the displacement according to the present invention includes: a passive rigid portion 100 that forms a rigidity between both sides so that the other side can be deformed in a state where one side is fixed; A plurality of elastic members 110 are coupled at one end to the upper structural body 110 at one side of the manual rigid portion 100 and at the other end to the lower structural body 120 at the other side of the manual rigid portion 100, The legs 130 of; A displacement measurement means (132) installed in the legs (130) and capable of measuring displacements in accordance with linear expansion and contraction of a specific stroke range of the legs (130); And a gripper mounting portion 122 formed on the lower structure 120 and to which a gripper portion 300 for gripping a component can be mounted; Wherein a plurality of legs 130 provided with the displacement measuring means 132 are arranged in the x-axis direction and the y-axis direction in which the legs 130 and the other side of the manual rigid portion 100 move in six degrees of freedom, z Six legs 130 are arranged to be inclined from each other so as to make a kinematic correspondence in both the axial direction, the θx direction, the θy direction, and the θz direction, and the displacement measuring means 132 provided in each of the legs 130 And the displacement of the other side of the manual rigid portion 100 can be calculated in six degrees of freedom using the measured value.

One side of the manual rigid portion 100 can be coupled to the arm 2100 of the robot and the other side can be deformed while one side of the manual rigid portion 100 is fixedly coupled to the arm 2100 of the robot have. At this time, the other side of the manual rigid portion 100 may be formed to be deformable by 2 degrees or more. The manual rigid portion 100 may be formed to have compliance so that it can be deformed in two or more degrees of freedom when an external force is applied, and to have a passive rigidity that can be restored to its original position by elasticity when an external force is removed. Here, the manual stiffness means that the other side can be deformed based on the fixed side when an external force is applied, and can be restored to its original position by elasticity when the external force acting is removed. The degree of freedom of 2 degrees or more may be, for example, a degree of freedom that can be transformed in the horizontal direction of the x axis and the y axis, and the z axis direction, the θ X direction, the θ Y direction, the θ Z direction, Can be added. Compliance is a material constant that indicates the ratio of the bending and the deformation force, and may be an amount that indicates the degree to which the other movable member can be deformed (moved or rotated) by an external force. One side (upper side) and the other side (lower side) of the manual rigid portion 100 may be connected to a rigid device 200-1 having a predetermined predetermined rigidity to have compliance.

The displacement measuring means 132 can measure the displacement of the manual rigid portion 100 according to the deformation of the manual rigid portion 100 and can measure the displacement of two degrees of freedom or more when the manual rigid portion 100 is deformed to more than two degrees of freedom. In this case, the displacement measuring means 132 may be a linear variable differential transformer (LVDT), for example. The number and type of the displacement measuring means 132 may be varied according to the number of degrees of freedom in which the manual rigid portion 100 is deformed.

The gripper mounting portion 122 is formed on the other side of the manual rigid portion 100 and the gripper portion 300 may be mounted on the gripper mounting portion 122. In this case, the gripper mounting portion 122 may be formed in various shapes so that the gripper portion 300 for gripping the component is mounted and firmly fixed. The gripper mounting portion 122 is fastened with a groove, And the like.

The gripper unit 300 may further include a gripper unit 300 mounted on the gripper mount unit 122. Thus, the gripper 300 can be used to grasp a part to be assembled. At this time, the gripper unit 300 may be formed in a finger shape, for example, and may be formed in various shapes according to the shape of a component to be gripped and the structure of a component to be assembled.

The manual rigidity gripper capable of measuring displacement according to the present invention can improve the assembling speed and the assembly quality by grasping the assembled state by using the displacement measuring means during the assembling work using the robot and correcting the path of the assembling position of the robot. Further, the applicability to various robots is high, and it is possible for the user to make safe and easy assembly teaching.

The gripper controller 400 further includes a gripper controller 400 coupled to the displacement measuring means 132 to detect the position of the lower end of the gripper 300 through displacements measured by the displacement measuring means 132 The gripper controller 400 is connected to a robot controller 2200 for controlling the movement path and the position of the robot so that the gripper controller 400 can calculate displacement The robot controller 2200 can provide the target movement path and the target position of the robot according to the displacement of the lower end of the gripper unit 300 calculated by the robot controller.

That is, when the gripper portion 300 is deformed due to an assembly error when inserting the component for assembling the component, the displacement calculating portion 410 calculates the displacement of the gripper portion 300 using the measured value of the displacement measuring portion 132, The calculated position of the lower end of the gripper unit 300 is transmitted to the robot controller 2200 and the target movement path and the target position of the robot 2000 are corrected by the robot controller 2200 can do. In other words, when there is an assembly error, since the first component 10 is inserted in a state where the gripper unit 300 is deformed, the degree of deformation of the gripper unit 300 is measured using the displacement measuring unit 132, It is possible to control the position of the robot 2000 so that the robot 300 is positioned at the correct insertion position.

[Example 2]

FIGS. 3 and 4 are conceptual diagrams of a variable passive rigidity gripper that can calculate the rigidity based on the displacement of the gripper caused by an external force, thereby giving the gripper an appropriate rigidity.

As shown, the variable passive rigidity gripper 1000, which is capable of displacement measurement according to the present invention,

The variable passive stiffness gripper 1000 according to the present invention is a variable passive stiffness gripper 1000 having a stiffness formed between both sides so that the other side can be deformed while one side is fixed, A variable stiffness device (200) mounted on the variable passive stiffness portion and capable of changing rigidity; Displacement measuring means (132) installed at the variable passive stiff portion and capable of measuring a displacement according to deformation of the variable passive stiffness portion; And a gripper mounting portion 122 formed on the other side of the variable passive stiffening portion and to which a gripper portion 300 for gripping a component can be mounted; . ≪ / RTI > The gripper unit 300 may further include a gripper unit 300 mounted on the gripper mount unit 122.

This is because the manual rigid portion 100 of Embodiment 1 is provided with the variable stiffening device 200 capable of changing the stiffness and the manual rigid portion 100 is easily deformed or deformed according to the rigidity of the changed variable stiffening device 200. [ . At this time, the variable passive stiffening portion is formed so as to be able to control the stiffness of the variable stiffening device 200 formed to be capable of changing the stiffness, and may be formed in various forms capable of adjusting rigidity. In the following, the manual rigid portion in Embodiment 1 and the variable manual rigid portion in Embodiment 2 will be denoted by reference numeral 100. [ The variable stiffening apparatus 200 may be interposed between one side and the other side of the variable passive stiffening member 100. The variable stiffening apparatus 200 may be disposed on one side of the variable passive stiffening member 100, The lower side of the variable stiffness device 200 may be coupled to the other side of the variable stiffness device 100. Also, the variable stiffness device 200 may have a specific stiffness and may be formed so as to be capable of changing its stiffness. For example, the variable stiffness device 200 may include an elastic body such as a spring and means capable of changing the stiffness of the elastic body.

Thus, when the stiffness of the variable stiffness device 200 is increased, the compliance of the variable manual stiffness gripper is reduced. On the contrary, when the stiffness is reduced, the compliance becomes larger. Accordingly, when the positional error or the machining tolerance between the parts to be assembled at the time of assembling is small, even if the rigidity of the variable stiffening apparatus 200 is increased, it can be assembled smoothly. In the case where the position error and the machining tolerance are large, If the stiffness of the variable passive stiffener 200 is changed to a small value, the variable passive stiffening portion 100 can be easily deformed and the stiffener can be smoothly assembled.

As described above, the variable manual rigidity gripper of the present invention can provide rigidity that can appropriately cope with a positional error and a machining tolerance of a workpiece at the time of assembly, and can be applied to various assemblies. Can be applied.

The gripper controller 400 further includes a stiffness adjusting unit 420 that can adjust the stiffness of the variable stiffness adjusting apparatus 200, Lt; / RTI >

That is, as shown, the variable stiffness device 200 is connected to the gripper controller 400 so that the stiffness of the variable stiffness device 200 can be adjusted by the stiffness adjuster 420 of the gripper controller 400.

The gripper controller 400 is further connected to the gripper controller 400 and the gripper controller 400 calculates the position of the lower end of the gripper unit 300 through the displacements measured by the displacement measuring unit 132 The gripper controller 400 includes a displacement calculator 410 and a stiffness calculator 430 connected to the stiffness controller 420. The displacement calculator 430 calculates the displacement of the gripper controller 400, The stiffness of the variable stiffness device 200 is adjusted through the stiffness adjuster 420 by calculating the target stiffness suitable for the assembly work in the stiffness calculator 430 according to the position of the lower end of the gripper part 300 calculated in step 410, .

That is, the rigidity controller 200 and the displacement measuring unit 132 are connected to the gripper controller 400, and when the gripper unit 300 is deformed due to an assembly error at the time of insertion for assembling parts, The position of the lower end of the gripper unit 300 can be calculated by the displacement calculating unit 410 of the gripper controller 400 using the values measured in the gripper unit 132 300 are deformed. The gripper controller 400 calculates the stiffness corresponding to a state in which the component is inserted and assembled in the stiffness calculator 430, And the stiffness of the variable stiffness device 200 is reduced through the stiffness adjuster 420 to a calculated stiffness value (so as to increase the compliance). Or the rigidity of the variable stiffness device 200 is kept small, the displacement of the gripper portion 300 is small or almost no, so that the stiffness of the variable stiffness device 200 is increased The vibration of the lower end of the gripper unit 300 can be reduced.

The gripper controller 400 is connected to a robot controller 2200 that controls a moving path and a position of the robot 2000 so that the gripper controller 400 controls the gripper unit 300 To the robot controller 2200 according to the displacement of the lower end of the robot 2000.

That is, as described above, the stiffness of the variable stiffness device 200 can be adjusted according to the displacement of the lower end of the gripper portion 300, and at this time, The position of the lower part of the robot 300 may be transmitted to the robot controller 2200 so that the robot control unit 2200 may correct the target movement path and the target position of the robot 2000. [

[Detailed Embodiment]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments using a detailed configuration of a manual rigidity gripper and a variable manual rigidity gripper capable of measuring displacement according to the present invention will be described. In the following description, the concept of a variable manual stiffness gripper capable of measuring displacement, which is formed so as to control the stiffness of the variable stiffness device 200, will be described.

6 and 7 are an assembled perspective view and an exploded perspective view showing a manual rigid gripper and a variable manual rigidity gripper capable of performing displacement measurement according to a detailed embodiment of the present invention, FIG. 8 is an exploded perspective view showing a Stuart platform according to the present invention, 9 and 10 are a perspective view and a front view showing a state where the Stewart platform and the balloon according to the present invention are assembled.

First, the manual rigid portion 100 may be a Stewart platform, and the variable stiffness device 200 may be a balloon capable of changing rigidity. Hereinafter, the manual stiffness portion is referred to as a Stewart platform 100 and the variable stiffness device is referred to as a balloon 200. [

As shown in the figure, the variable passive rigidity gripper 1000 according to the present invention includes a top structure 110, a bottom structure 120 spaced apart from the bottom of the top structure 110, A stuart platform 100 including a plurality of legs 130 connected at both ends thereof to the main body 110 and the substructure 120 so as to be stretchable; An elastic balloon 200 disposed inside the Stewart platform 100 and capable of adjusting air pressure; And a gripper part (300) coupled to the lower structure (120) of the Stewart platform (100) and capable of gripping the part; . ≪ / RTI >

The Stewart platform 100 may largely consist of an upper structure 110, a lower structure 120, and a plurality of legs 130. The upper structure 110 may be formed in a disc shape and the upper structure 110 may be coupled to an end of the arm 2100 of the robot 2000. The upper structure 110 is formed with a plurality of coupling holes formed on the upper surface thereof with female threads, and can be firmly coupled to the end of the arm 2100 by fastening means. The lower structure 120 may be formed in a disc shape, and a gripper unit 300 may be coupled to a lower surface of the lower structure 120 to hold a component to be assembled. The leg 130 is connected to the upper structure 110 and the lower structure 120. The upper end of the leg 130 is connected to the lower surface of the upper structure 110 and the lower end is connected to the upper surface of the lower structure 120 . The legs 130 are formed to be expandable and contractible so that the lower structure 120 can be freely moved and rotated while the upper structure 110 is fixed. The leg 130 may be disposed between the upper structure 110 and the lower structure 120 and may be disposed inside the upper portion of the upper structure 110 and the lower portion of the lower structure 120. That is, the legs 130 may be disposed within the diameter range of the upper structure 110 and the lower structure 120, but may be disposed outside the center within the diameter range. The legs 130 may be formed in six, for example, and the adjacent legs 130 may be inclined in opposite directions to each other. That is, the two neighboring legs 130 may be connected to the upper structure 110 so that upper ends thereof are adjacent to each other, and connected to the lower structure 120 so that lower ends thereof are adjacent to each other. Thus, the Stewart platform 100 structure can be formed by the superstructure 110, the substructure 120, and the plurality of legs 130.

The balloon 200 may be a spherical balloon made of an elastic material and may be formed so that compressed air can be supplied to or discharged from the balloon to control the pneumatic pressure inside the balloon. At this time, as the compressed air is supplied or discharged, the balloon 200 may be expanded or contracted to change the volume. When the compressed air is supplied, the pressure inside the balloon is increased and when the compressed air is discharged, the pressure inside the balloon may be lowered. The balloon 200 may be disposed inside the Stewart platform 100. That is, a balloon 200 is disposed between the upper structure 110 and the lower structure 120 forming the structure of the Stewart platform 100 so that the upper and lower sides of the balloon 200 can be in close contact with each other, 130, respectively. The balloon 200 is spaced apart from the legs 130 so that the balloon 200 is not contacted with the legs 130 even when the balloon 200 is inflated.

The gripper unit 300 is a part capable of gripping a component to be assembled and includes a finger block 310 coupled to a lower surface of the lower structure 120 and a finger block 310 coupled to the finger block 310, And may include a pair of fingers 320. At this time, the fingers 320 may be formed in a structure that can be opened or closed to hold or place the components. For example, as shown in the figure, the fingers 320 may be combined with the structure capable of sliding along the finger blocks 310 . In addition, the finger block 310 may be provided with an actuator to open or close the pair of fingers 320, or may be configured to operate the fingers 320 in various structures.

12 and 13, when a part is inserted into the hole of the object to be assembled, the first part 10 to be inserted into the finger 320 is gripped by the insertion of the fixed second part 20, When the first part 10 is inserted into the insertion hole 21 by moving to the position where the hole 21 is located, there is a positional error between the first part 10 and the insertion hole 21, When the gripper portion 300 and the lower structure 120 are inserted together while being moved in the horizontal direction with respect to the upper structure 110 as shown in FIG. So that the gripper 300 can be inserted in a bent state or twisted about a vertical axis. Since the stiffness of the gripper portion 300 depends on the internal pressure of the balloon 200 which is disposed inside the Stewart platform 100 and is in close contact with the upper structure 110 and the lower structure 120, When the rigidity is increased by increasing the pressure of the balloon 200, the assembly can be performed only when there is a small position error. On the contrary, if the pressure of the balloon 200 is decreased to reduce the rigidity, Even when the error is large, the position and direction of the gripper portion are changed, so that the component can be easily inserted. Here, compliance is a material constant indicating the ratio of the bending and the deforming force, which is an amount indicating the degree to which the lower structure 120 movable with respect to the fixed upper structure 110 is easily deformed (moved or rotated) by an external force .

Accordingly, since the rigidity of the gripper can be adjusted by adjusting the air pressure of the balloon 200, the manual rigid gripper 1000 capable of measuring the displacement of the present invention can be used as an assembly robot for assembling components with large assembly errors, And can be applied to various assemblies such as a vertical direction and a horizontal direction.

Further, since the assembly can be easily performed even when the assembly error is large, there is an advantage that the user can safely and easily assemble teaching even when the user is unable to adjust the position with the naked eye.

In addition, the lower structure 120 may be formed to have six degrees of freedom.

That is, as shown in FIGS. 14 to 17, the gripper unit 300 including the lower structure 120 moves in the three-dimensional axial directions X, Y, and Z axes, and the rotational directions? X , the Stewart platform 100 can be formed so that rotation in the directions of? Y ,? Z is possible. Thus, the assembly can be assembled while the gripper is moved in the axial direction due to an assembly error or the like when the component is assembled and the position is corrected, or the angle at which the assembly is rotated about the axis is corrected.

The legs 130 can be linearly expanded and contracted and both ends of the legs 130 can be coupled to the upper structure 110 or the lower structure 120 by ball joints 131.

That is, the legs 130 may be formed in a structure such that they can be linearly reduced or extended in a linear manner, such as a linear actuator. For example, even if the legs 130 are formed in a structure that can be linearly expanded or contracted within a specific stroke range such as a hydraulic or pneumatic cylinder 11 can be formed such that a displacement [delta] due to elongation and shrinkage occurs. It is preferable to form the shape linearly changeable by the external force. In addition, the legs 130 are formed in a shape in which spherical balls are coupled at both ends so that the balls are inserted in the upper structure 110 or the lower structure 120 while being inserted, The ball joint 131 may be coupled to the ball joint 131. At this time, in addition to the ball joint 131, the ball joint 131 may be combined with an elastic body that can be freely bent without being separated from the joined state, or may be coupled in various forms. Here, since the elastic force of the balloon 200 acts to expand the gap between the upper structure 110 and the lower structure 120, the legs 130 are positioned at the maximum length The upper structure 110 and the lower structure 120 may be in parallel with each other.

The upper and lower structures 120 and 120 are respectively provided with guide grooves 111 and 121 so that the upper and lower sides of the balloon 200 are inserted into the guide grooves 111 and 121, And can be inserted and adhered to each other.

That is, as shown in FIGS. 8 to 10, the upper and lower sides of the balloon 200 are inserted into close contact with the placement grooves 111 and 121 to allow the Stewart platform 100 to receive an external force due to the elasticity of the balloon 200 It can be easily restored to its original state. Since the position of the balloon 200 can be fixed, even if a change in the structure of the Stewart platform 100 or a change in the air pressure of the balloon 200 occurs, the legs 130 may not contact the balloon 200 , A more free modification of the Stewart platform 100 may be possible.

In addition, the upper structure 110 may have an inlet / outlet flow passage 112 through which the compressed air can be injected and discharged, and the balloon 200 may be connected to the inlet / outlet flow passage 112.

That is, as shown, the inlet / outlet flow path 112 may be connected so that compressed air is supplied to the balloon 200 or air is discharged from the balloon 200. For example, the inlet / outlet flow path 112 may be formed as a pipe to be connected to the balloon 200 and connected thereto. The balloon 200 and the inlet / outlet flow path may be formed separately or integrally. The upper structure 110 may have grooves to allow the inlet / outlet flow path 112 to be disposed therein. The balloon 200 may be connected to the inlet / outlet flow path 112 by forming an inlet / outlet flow path 112 in a hole shape in the upper structure 110 itself. To the inlet / outlet flow path 112, a one-touch fitting or a quick coupling for connection such as a pneumatic hose may be coupled to the end portion. In FIG. 3, holes or the like through which the compressed air is supplied or discharged to the balloon 200 are not shown. However, the balloon 200 may be provided with a hole or a tube to be connected to the inlet / outlet flow path 112. Here, the passive stiffness member may be a variable passive stiffness portion including the inlet passage 112 connected to the variable stiffness device 200 formed or coupled to the upper structure 110 of the Stewart platform 100. That is, the passive stiffening portion formed to be able to control the elasticity of the variable stiffener 200 through the inlet / outlet passage 112 may be an example of the variable passive stiffening portion.

In addition, the legs 130 may include displacement measuring means 132 capable of measuring displacements due to linear expansion and contraction, respectively.

That is, each of the legs 130 may include a displacement measuring means 132 for measuring the length of the legs 130. The displacement measuring means 132 may be installed in the legs 130 so as to be inserted into the legs 130, It is possible to measure the displacement due to the linear expansion and contraction of the elastic member 130. The displacement measuring means 132 may be provided outside the legs 130 or the displacement measuring means 132 itself may be formed by the legs 130. The displacement measuring means 132 may be a linear variable differential transformer (LVDT). The LVDT is a type of an electrical transducer for measuring a linear distance difference. Three solenoid coils are disposed in the form of a tube. And the other two are located outside, and a cylinder-shaped magnetic core moves along the center of the tube to indicate the position of the object to be measured. Alternatively, the displacement measuring means 132 may be formed of an encoder, a potentiometer, or the like to measure a change in length of the leg 130 as it is stretched or shrunk.

The gripper controller 400 further includes a gripper controller 400 connected to the displacement measuring means 132. The gripper controller 400 detects the displacement of the gripper unit 300 through the displacements measured by the displacement measuring means 132, The position of the gripper can be controlled by calculating the position of the gripper.

That is, displacement measuring means 132 are connected to the gripper controller 400 so that when the gripper portion 300 is deformed due to an assembling error or the like at the time of insertion for assembling the components, the values measured by the displacement measuring means 132 The position of the lower end of the gripper unit 300 can be calculated by the gripper controller 400 and the position of the gripper unit 300 can be controlled using the position value of the lower end of the gripper unit 300 have. In other words, when there is an assembly error, since the first component 10 is inserted in a state where the gripper portion 300 is deformed, the degree of deformation of the gripper portion 300 is measured using the displacement measuring means 132, The position of the robot 2000 can be controlled by the gripper controller 400 so as to come to the correct insertion position. The gripper controller 400 is connected to the robot controller 2200 for controlling the movement path and the position of the robot 2000 so that the gripper unit 300 calculated by the displacement calculation unit 410 of the gripper controller 400, The target path and target position of the robot 2000 can be provided to the robot controller 2200 according to the displacement of the lower end.

As described above, the passive rigid gripper of the present invention grasps the assembled state at the time of assembling operation and can modify the path of the assembled position, thereby improving the assembling speed and the assembling quality.

In addition, the gripper controller 400 may adjust the pneumatic pressure of the balloon 200 according to the displacements measured by the displacement measuring means 132. That is, displacement measuring means 132 are connected to the gripper controller 400 so that when the gripper portion 300 is deformed due to an assembling error or the like at the time of insertion for assembling the components, the values measured by the displacement measuring means 132 The gripper controller 400 can calculate the position of the lower end of the gripper unit 300 and can determine whether the gripper unit 300 is deformed to such an extent that the part can be inserted smoothly. Thus, if it is determined that there is an assembly error that can not be smoothly inserted, the gripper controller 400 lowers the air pressure of the balloon 200 to increase the compliance and controls the gripper unit 300 to be easily deformed, The gripper portion 300 is deformed and smooth parts can be assembled. In addition, if the gripper unit 300 is deformed or is small even if it is not assembled or assembled, the air pressure of the balloon 200 is increased to lower the compliance, so that the gripper unit 300 is not easily deformed, ) Can be reduced.

The rigidity of the variable stiffness device 200 can be adjusted in accordance with the displacement of the lower end of the gripper 300. In this case, the gripper 300, which is calculated by the displacement calculation unit 410 of the gripper controller 400, The position of the bottom position may be transmitted to the robot controller 2200 so that the robot control unit 2200 may correct the target movement path and the target position of the robot 2000. [

In this case, the gripper controller 400 may be disposed on the upper side of the upper structure 110, and the upper structure 110 may be formed as a container having a hollow interior and an opened upper side. Inside the upper structure 110, (400) can be positioned. Alternatively, the gripper controller 400 may be installed separately and connected to the displacement measuring means 132 or the balloon 200, and the gripper controller 400 may be integrally formed with the robot controller 2200, .

 A flexible material cover 140 may be coupled to the peripheral surfaces of the upper structure 110 and the lower structure 120 so as to surround the outer sides of the legs 130. At this time, the cover 140 may be formed in various shapes such as a mesh or an elastic material.

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 as defined by the appended claims. It goes without saying that various modifications can be made.

1000: Manual stiffness gripper
100: Manual rigidity
110: upper structure 111:
112: inlet / outlet port
120: Lower structure 121:
122: Gripper mounting part
130: leg 131: ball joint
132: displacement measuring means
140: cover
200: variable stiffness device 200-1: rigid device
300:
310: finger block 320: finger
400: Gripper controller
410: Displacement calculation unit 420: Stiffness control unit
430: Rigidity calculation section
2000: robot 2100: arm
2200: Robot controller
10: first part 20: second part
21: Insertion hole

Claims (8)

A passive rigid portion that forms a rigidity between both sides so that one side can be deformed while the other side is fixed;
A plurality of legs each having one end coupled to an upper structure at one side of the manual rigid portion and the other end connected to a lower structure at the other side of the manual rigid portion and linearly expandable and contractible in a specific stroke range;
Displacements measuring means respectively installed in the legs for measuring displacements in accordance with linear expansion and contraction of a specific stroke range of the legs; And
A gripper mount formed on the lower structure, the gripper mount being mountable with a gripper portion for gripping the component; , ≪ / RTI &
The plurality of legs provided with the displacement measuring means are mechanically supported in both the leg length and the motion of the other side of the manual rigid portion in the x-axis direction, the y-axis direction, the z-axis direction, the θx direction, the θy direction, Six legs are staggered from each other so as to be able to establish a relationship,
Wherein the displacement of the other side of the manual rigid portion can be calculated at six degrees of freedom using a value measured by the displacement measuring means provided in each of the legs.
The method according to claim 1,
And a gripper portion mounted on the gripper mounting portion.
3. The method of claim 2,
Further comprising a gripper controller to which said displacement measuring means is connected,
The gripper controller includes a displacement calculator for calculating a position of a lower end of the gripper unit based on the displacements measured by the displacement measuring unit. The gripper controller is connected to a robot controller for controlling a movement path and a position of the robot,
Wherein the gripper controller is capable of measuring a displacement capable of providing a target movement path and a target position of the robot to the robot controller according to a displacement of the lower end of the gripper portion calculated by the displacement calculation unit.
A variable passive stiffening part which forms a stiffness between both sides so that one side can be deformed while the other side is fixed and the formed stiffness can be adjusted;
A variable stiffness device installed in the variable passive stiffness portion and capable of changing rigidity;
A plurality of legs, one end of which is coupled to an upper structure at one side of the variable passive stiffening portion and the other end of which is coupled to the lower structure at the other side of the variable passive stiffening portion,
A displacement measuring means installed in each of the legs to measure displacement according to linear expansion and contraction of the leg; And
A gripper mount formed on the lower structure, the gripper mount being mountable with a gripper portion for gripping the component; A variable manual stiffness gripper capable of measuring displacement comprising:
5. The method of claim 4,
And a gripper portion mounted on the gripper mounting portion.
5. The method of claim 4,
Further comprising a gripper controller to which said variable stiffness device is connected,
Wherein the gripper controller includes a stiffness adjusting portion capable of adjusting the stiffness of the variable stiffness device.
The method according to claim 6,
A displacement measuring means is further connected to the gripper controller,
Wherein the gripper controller includes a displacement calculator for calculating a position of a lower end of the gripper through displacements measured by the displacement measuring means,
Wherein the gripper controller includes a stiffness calculator connected to the displacement calculator and the stiffness controller,
A variable manual rigidity gripper capable of measuring a displacement by calculating the stiffness in the stiffness calculation unit according to the position of the lower end of the gripper unit calculated by the displacement calculation unit and adjusting the stiffness of the variable stiffness device through the stiffness adjustment unit.
8. The method of claim 7,
The gripper controller is connected to a robot controller for controlling the movement path and position of the robot,
Wherein the gripper controller is capable of measuring a displacement capable of providing a target moving path and a target position of the robot to the robot controller according to a displacement of the lower end of the gripper portion calculated by the displacement calculating portion.
KR1020160039928A 2016-04-01 2016-04-01 Passive compliance gripper and variable passive compliance gripper with displacement measurement function KR101688867B1 (en)

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KR1020160039928A KR101688867B1 (en) 2016-04-01 2016-04-01 Passive compliance gripper and variable passive compliance gripper with displacement measurement function
US16/083,760 US10987816B2 (en) 2016-04-01 2017-03-23 Passive stiffness gripper
PCT/KR2017/003111 WO2017171303A1 (en) 2016-04-01 2017-03-23 Passive stiffness gripper

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KR20210127838A (en) 2020-04-14 2021-10-25 한국기계연구원 Tool coupling device for robot being capable of active moving
KR20210144971A (en) 2020-05-21 2021-12-01 한국기계연구원 Robot tool system

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KR20210127838A (en) 2020-04-14 2021-10-25 한국기계연구원 Tool coupling device for robot being capable of active moving
KR20210144971A (en) 2020-05-21 2021-12-01 한국기계연구원 Robot tool system

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