KR101262840B1 - Human-robot cooperative system and method of parts based on the same - Google Patents

Abstract

The present invention relates to a method for assembling parts based on a human-robot collaboration system for assembling parts through a robot, which operates the robot by direct teaching of an operator and stores the position and motion information of the robot while performing assembly of the parts. An initial teaching assembly step; A regeneration assembly step of automatically assembling parts based on the stored position and motion information of the robot; And an additional teaching correction step in which an operator additionally teaches and corrects the position and operation information of the robot when an assembly error of a component occurs in the regeneration assembly step.

Description

HUMAN-ROBOT COOPERATIVE SYSTEM AND METHOD OF PARTS BASED ON THE SAME}

The present invention relates to a method for assembling a part using a human-robot collaboration system, and more particularly, a human-man who performs a series of working processes for moving and inserting a part to be inserted into and then contacting an inserted part held by a gripper of a robot. It relates to a method of assembling parts based on a robot collaboration system.

In the existing factory automation (FA) system using industrial robots, each time a new task is instructed, a complex program suitable for the working environment is required, which is expensive in time and money. Therefore, only a large company with a large production line and robotic experts can build this factory automation system. However, in the case of small and medium-sized production-oriented small and medium-sized companies, the existing industrial robot application method that requires complicated operation method and high cost is inappropriate in terms of production efficiency.

This problem is a major factor in slowing the growth rate of the global industrial robot market today. In fact, most small and medium-sized companies are sticking to a production system that employs cheaper manpower than automated systems using industrial robots. However, the decline and aging of population growth today is expected to be a major factor in the labor supply imbalance of SMEs in the near future.

In order to overcome this problem, a paradigm shift of industrial robots has been raised in Europe, the United States, and Japan. A typical example is the human-robot collaborative manipulation technology that provides intuitive interaction between industrial robots and workers as a transitional stage from the existing industrial robots to intelligent service robots. This technology features an easier and more intuitive robot motion command generation method (direct teaching method), which allows the operator to send the motion command to the robot only by teaching through the interface device, and the robot can reproduce the operator's intention and skill as it is. Can be.

Conventional human-robot collaborative manipulation technology using heavy parts generally consists of four steps as follows.

1) Step 1 (Gripping Work): The worker grasps a heavy part through a gripper connected to a lifting device (hoist, etc.).

2) Step 2 (Transport): The worker grasps the parts held by the lifting device to the position where the work will be performed.

3) Step 3 (contact and joining): While the operator visually observes the situation, the gripped part is brought into contact with the part to be joined and the center axes of the parts to be joined are matched with each other.

4) Step 4 (Joining or Inserting): The operator observes the situation visually and engages (or inserts) the gripped part with the part to be joined. At this time, the blockage phenomenon caused by the central axis mismatch between the two parts is solved by the operator's intuition by applying shock or vibration to the parts.

Since the conventional human-robot collaborative manipulation technology is performed depending on the expertise of the worker, there is a problem that not only a skilled worker is required but also the worker must carefully observe the work situation generated in every detail work. In addition, the conventional human-robot collaborative manipulation technology has a problem that results in damage of parts, risk of work and increased tact time due to work information (for example, contact force between parts, etc.) that is hard to observe by the human eye. have.

Patent Document 1: Publication No. 10-0969585

The present invention has been derived to solve the above problems, even non-skilled person can perform the assembly work, and can be easily applied to various assembly parts by changing the work processor, the change in the external environment according to the assembly of the worker And to provide a component assembly method based on the human-robot collaboration system that can perform the assembly operation of the component while the robot detects.

In order to achieve the above object, the present invention is a human-robot collaboration system-based component assembly method for assembling components through a robot, the position of the robot while performing the assembly of the parts by operating the robot by direct teaching of the operator And an initial teaching assembly step of storing operation information; A regeneration assembly step of automatically assembling parts based on the stored position and motion information of the robot; And an additional teaching correction step of correcting the position and operation information of the robot by additional teaching by an operator when an assembly error of the component occurs in the regeneration assembly step.

In addition, the part may include an insert part having one or more pegs and an insert part having one or more holes into which the pegs can be inserted.

The initial teaching assembly step may include: an insertion part gripping step of registering the coordinate system of the robot initial posture and holding the insertion part, and storing the position and motion information of the robot until the operation completion time; An insert part moving step of moving the gripped insert part and placing it on the workbench, and storing the position and motion information of the robot until the completion of the operation; A part to be inserted, which holds the part to be inserted and stores the position and motion information of the robot until the operation completion time; An inserted part moving step of moving the gripped inserted part over the inserted part placed on the work table and storing position and motion information of the robot until the completion of the operation; A part insertion preparation step of contacting the inserted part with the inserted part to match the peck of the inserted part with the hole of the inserted part, and storing the position and the motion information of the robot until the completion of the operation; And a component insertion step of inserting the peck of the inserted component into the hole of the inserted component to determine the insertion end position, and storing the position and the operation information of the robot until the completion of the operation.

In addition, the component insertion preparation step may include a primary contact step of determining the position of the inserted part by bringing the inserted part into close contact with the inserted part; A second contact step of rotating the inserted part about an imaginary axis, wherein each of both edges of the inlet of the hole of the inserted part generates two-point contact with the side and front end edges of the peck of the inserted part; And moving the inserted part so that the contact between the leading edge of the peg of the inserted part and the inlet edge of the hole of the inserted part is dropped, and then rotating the inserted part in a direction opposite to the rotation direction in the second contact step. The front end surface of the peck of the inserted part is located in the inner space of the hole of the inserted part, and the front end surface of the peg and the bottom surface of the hole are parallel to each other, and the center axis of the peck and the central axis of the hole are also parallel. And a matching step to maintain.

In addition, the component insertion preparation step and the component insertion step, the operator can perform the teaching work while confirming the contact force between the insertion part and the part to be inserted.

In addition, the regeneration assembly step, the insertion part holding step, the insertion part moving step, the inserted part gripping step, the inserted part moving step, based on the position and operation information of the robot stored in the initial teaching assembly step, The component insertion preparation step and the component insertion step may be sequentially reproduced. Here, the regeneration assembly step, it is determined whether the position and operation information of the robot of each step to be reproduced match the information taught in the initial teaching assembly step, and stops the regeneration assembly step if the mismatch error exceeds the set error can do.

In addition, the additional teaching correction step, if the regeneration assembly step is stopped, the operator performs additional teaching to correct the position and operation information of the robot, and then all the regeneration assembly of the position and operation information of the robot changed by the additional teaching The operation command signal of the robot corresponding to the step may be corrected.

In addition, the component assembly method based on the human-robot collaboration system may additionally store the coordinate system information of the robot in consideration of the distance between the first gripped part and another part in order to grip the plurality of parts on the pallet.

In addition, the parts assembly method based on the human-robot collaboration system may change the motion characteristics of the robot to high speed or precision motion by changing an admittance parameter suitable for the current job according to the teaching range of the operator. At this time, the observer may automatically change the admittance parameter.

In addition, the component assembly method based on the human-robot collaboration system determines the rotation angle of the inserted part through the diameter of the peck of the inserted part and the hole diameter of the inserted part, and monitors whether the inserted part and the inserted part are in contact with each other. This can be determined from the contact force signal of the device.

In addition, the component assembly method based on the human-robot collaboration system prevents component breakage and system damage when contact occurs between components during the initial teaching assembly stage, the regeneration assembly stage, and the additional teaching correction stage, and the contact phenomenon occurs. If not, an impedance controller with a position controller can be used to improve the robot's path tracking performance.

In addition, the present invention to achieve the above object is a robot capable of holding and moving parts; An interface capable of transmitting a command of a worker to a robot or delivering external environment information to a worker at work; An encoder capable of identifying position information of the robot; And a cooperative system controller capable of performing the robot in an initial teaching mode, a regeneration mode, and an additional teaching correction mode. Here, the initial teaching mode is a mode for storing the position and operation information of the robot while performing the assembly of the parts by operating the robot by the direct teaching of the operator during the assembly of the initial part, the regeneration mode in the initial teaching mode In the mode of automatically assembling the parts based on the information of the stored robot, the additional teaching correction mode is a mode for correcting the position and operation information of the robot by additional teaching when the assembly error occurs in the regeneration mode.

The cooperative system controller may further include: a robot path and motion generation unit for determining a path and a motion characteristic of the robot through the teaching force information of the worker; A robot driving device control unit for converting the robot path and motion characteristic information into a robot synchronization signal and transmitting the same to a robot driving device; A teaching data storage unit for storing the position and motion information of the robot by the first teaching or additional teaching of the operator; A teaching data correction unit for correcting stored information through additional teaching of an operator; And a teaching data reproducing unit capable of converting the information transmitted to the teaching data storing unit or the teaching data correcting unit into various signals to be followed by the robot in the reproducing mode of the robot.

The collaborative system controller may further include an impedance controller for redefining the path and operating characteristics of the robot through contact force information and impedance parameters of the component in the inter-part contact situation; And a position controller for compensating for the path following performance degradation of the robot generated in the non-contact situation.

In addition, the cooperative system controller, the switch for returning the robot to the initial position, the robot gripper ON / OFF switch for gripping the workpiece, the switch for selecting the teaching mode and the regeneration mode, the emergency situation generated during the regeneration mode A window that displays the current working status of the robot by the robot's movement characteristics, such as an alarm for notification, operator's teaching power, contact force generated when touching parts, the tool coordinate system of the robot in operation, and the tool coordinate system of the robot to be reached. It may further include a monitoring unit including a window for displaying information.

In addition, the human-robot collaboration system for assembly of parts may further include a multi-axis force / torque sensor for measuring the teaching force signal of the operator.

The present invention eliminates the need for a teaching pendant or the like for generating an operation command of a robot, and reduces the effort of complicated programming tasks using existing robot experts.

In addition, the present invention can solve the problem of productivity degradation due to the future supply and demand imbalance problem by adopting the method of reproducing the robot through the teaching work reflecting the skilled work skills of the worker by breaking the existing work method depending on the existing manpower In addition, it can be used as a robot supporting small and medium-sized businesses focused on producing small quantities of various varieties.

In addition, the present invention is delivered to the operator through the monitoring device to the excessive contact force generated when the object is in contact with obstacles and other surroundings, and the object that the operator does not understand, the safety generated during operation by controlling the contact force inside the robot controller The accident can be prevented in advance.

In addition, the present invention, unlike the conventional direct teaching method of the robot can solve the problem caused by the regeneration of the robot through the additional teaching of the operator, and can reflect the corrected result through the additional teaching in the subsequent regeneration, assembly work Ensure the integrity of

1 is a schematic plan view of a human-robot collaboration system for assembling parts according to an embodiment of the present invention.
2 is a schematic front view showing the configuration of a human-robot collaboration system for assembling parts according to an embodiment of the present invention.
3 is a view showing an embodiment of a component that can be applied to the present invention.
4 is a diagram illustrating a configuration of a cooperative system controller of FIG. 2.
5 is a diagram illustrating a monitoring unit of FIG. 4.
6 is a flowchart illustrating a component assembly method based on a human-robot collaboration system according to an exemplary embodiment of the present invention.
7 shows an insert part gripping step during an initial teaching assembly step.
8 is a view showing an insertion part moving step during an initial teaching assembly step.
9 is a view showing a part to be inserted during the initial teaching assembly step.
FIG. 10 is a view showing an insertion part moving step during an initial teaching assembly step. FIG.
FIG. 11 shows a first contact step of an initial teaching assembly step. FIG.
FIG. 12 shows a second contact step of an initial teaching assembly step. FIG.
FIG. 13 is a detailed view of the secondary contact step of FIG. 12.
FIG. 14 shows a mating step of an initial teaching assembly step. FIG.
FIG. 15 is a detailed view (kinematic analysis) of the matching step of FIG. 14.
FIG. 16 shows a part insertion step during an initial teaching assembly step. FIG.
Fig. 17 is a view showing an insertion part gripping step (occurrence of gripping error) during the regeneration assembly step.
18 is a view showing the path correction of the robot for moving to the insertion ready position in the regeneration assembly step.
19 is a block diagram of the cooperative system controller of FIG. 2.

Hereinafter, a method for assembling parts based on a human-robot collaboration system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, preferred embodiments of the present invention have been described, but the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims, the detailed description of the invention, and the accompanying drawings. Naturally, it belongs to the range of.

1 and 2, a human-robot collaboration system 100 according to an embodiment of the present invention may include a robot 20 and a robot 20 that perform an assembly operation according to a creation command of an operator 10. It carries pallets 31 and 32 on which the insertion part P1 and the insertion part P2 are placed on the left and right sides of the center, and the work bench 40 and the assembly finished product P3 where the assembly work of the parts P1 and P2 is performed. It includes a conveyor (50). The pallets 31 and 32 and the work table 40 are provided with positioning and fixing devices 33, 34 and 41, respectively, so that the parts P1 and P2 can be placed in a constant position and orientation at all times while being horizontal to the ground. . In particular, in the case of the pallets 31 and 32, pallets designed to keep the plurality of parts P1 and P2 at regular intervals are used. In addition, the worker work area S is formed between the worker 10 and the robot 20 by a hardware boundary (such as a safety fence) and a software boundary (such as a limitation of the work space of the robot) to promote the safety of the worker.

In addition, the human-robot collaboration system 100 according to an embodiment of the present invention is an interface (HRI) for transmitting a variety of work information, such as a contact force generated when the operator's work command to the robot, or conversely in contact with the external environment; Human-Robot Interface) and a cooperative system controller 70 for performing component assembly tasks in various modes of operation. The cooperative system controller 70 includes a graphical user interface (GUI) 80 for facilitating direct teaching of an operator.

The robot 20 includes a multi-axis force / torque sensor 21 for measuring a worker's teaching force (force / torque generated from the worker to generate a work command of the robot), and a robot gripper for gripping a workpiece. 22) and an encoder 23 for grasping position information of the robot 20 in operation.

As shown in Fig. 3, the work part handled in the present invention includes an insert part P1 having a peg of a circular cross section in which two or more lengths are the same and the central axes are parallel to each other, and the insert part P1. It is a part to be inserted (P2) having two or more holes (holes) that can be inserted, and is a heavy weight mechanical part that is somewhat difficult to assemble only by the operator's manpower. In addition, this inserted part (P2) is uneven side can be moved to the gripping center point when gripping with the robot gripper (22). In the present invention, an error resulting from this phenomenon is defined as a gripping error. The component applied to the present invention is not limited to this embodiment, and its shape and arrangement may be variously modified.

In addition, the cooperative system controller 70 may include a robot path and motion generation unit 71 for determining the path and motion characteristics of the robot 20 through the teaching force information (force / torque sensor signal) of the first operator, and a part ( Impedance controller 72 redefining the motion path and motion characteristics of the robot 20 in the contact situation through the contact force information between P1 and P2 and the mechanical impedance factor of the component, and the path following performance degradation of the robot 20 It includes a position controller 73 to supplement.

The motion path and motion characteristic information of the redefined robot 20 are converted into a synchronization signal through the robot drive unit controller 74 and then transferred to the robot drive unit. At the same time, the information generated from the impedance and position controllers 72 and 73 is first transferred to the teaching data storage 75 so that the robot 20 follows the regeneration of the robot 20 after a direct teaching operation by the operator. Various signals to be converted are converted in the teaching data reproducing section 76, and secondly, this information is transmitted to the monitoring section 80 to facilitate direct teaching work of the operator.

If the regeneration operation conditions (environmental and necessary matters) by the robot 20 are different from those of the teaching operation, the regeneration operation is impossible or unnecessary contact between parts is not performed even though the robot 20 accurately follows the stored path. It can be considered to have occurred. In this case, the robot 20 automatically stops the regeneration operation and prevents damage or damage between components through the proposed impedance controller 72. In addition, the worker 10 performs the work of the stopped step in the whole assembly work process through additional teaching work. The teaching force information of the operator generated through the additional teaching work is transmitted to the teaching data correction unit 77 and used to correct and supplement the movement path and motion characteristics of the previously stored robot.

In addition, the monitoring unit 80 includes a switch 81 for returning the robot 20 to an initial position defined before the teaching and reproducing operation, a robot gripper ON / OFF switch 82 for gripping parts, and a teaching operation. And a switch 83 for selecting a regeneration operation, an alarm lamp 84 for informing an emergency situation generated during regeneration operation, a window 85 for displaying the current operation state by the robot's movement characteristics, and an operator Display window 86 for displaying the teaching force of the operator currently generated to promote direct teaching of the work, window 87 for displaying the contact force generated when contacting parts, and tool coordinate system information of the operating robot. A window 88 for displaying the tool coordinate system information of the robot to be reached.

In the following, the order of assembly of parts by the human-robot collaboration system 100 will be described.

The method of assembling parts of the human-robot collaboration system 100 according to the embodiment of the present invention comprises an initial teaching assembly step S1, a regeneration assembly step S2, and an additional teaching correction step S3.

Initial teaching assembly step (S1) is a step of storing the position and operation information of the robot 20 while performing the assembly of the parts (P1, P2) by operating the robot 20 by direct teaching of the operator. The initial teaching assembly step (S1) proceeds in the order of eight steps in the embodiment of the present invention. Through the initial teaching assembly step (S1), the operator's intention (such as the strength of the contact force during contact between work paths and parts) is converted into motion path and motion characteristic information of the robot 20 through the interface 60, and this information Is stored in the teaching data storage 75. In addition, since this information is displayed in the monitoring unit 80, the operator can check whether the robot path by teaching reaches the target path of the robot calculated through the dimensions and kinematic analysis of the parts in advance.

The regeneration assembly step S2 is a step of automatically regenerating and assembling the parts P1 and P2 based on the position and operation information of the robot 20 stored in the initial teaching assembly step S1. The regeneration assembly step S2 is started by the information stored in the teaching data storage unit 75 being converted into a robot operation command signal, and the operator operating the regeneration job conversion switch of the monitoring unit 80. The regeneration assembly step (S2) is performed in the same manner as the initial teaching assembly step (S1) of the operator, the alarm of the monitoring unit 80 when each step is impossible (including excessive contact force occurrence situation) due to various errors such as a gripping error As the lamp 84 operates, the playback operation is automatically stopped.

The additional teaching correction step (S3) is a step in which the operator additionally teaches and corrects the position and operation information of the robot 20 when an assembly error of a component occurs in the regeneration assembly step (S2). The operator performs the work of the step where the reproducing operation is stopped through additional teaching, and the generated teaching force information is transmitted to the teaching data correction unit 77 to correct and supplement the movement path and motion characteristics of the existing robot. Used.

First, the embodiment of the initial teaching assembly step (S1) will be described step by step.

The first step is the insert part gripping step (S1-1). The robot 20 approaches the insertion part P1 placed on the pallet 31 through direct teaching by the operator in the robot initial pose (where the orientation of the robot tool coordinate system is the same as the base coordinate system of the robot). do. Subsequently, as shown in FIG. 7, the operator operates the robot gripper 22 to grip the insertion part P1. The robot tool coordinate system information up to the end of gripping and the operation information of the robot gripper 22 are stored in the teaching data storage unit 75. At this time, the robot path required for the gripping operation is added in consideration of the gap between the insertion parts P1 placed on the pallet 31.

The second step is the insertion part moving step S1-2. The robot 20 moves the gripped insertion part P1 to the work bench 40 through the direct teaching work of the worker and places it on the work bench 40 (FIG. 8). Thereafter, through the positioning and fixing device 41, the insert P1 placed on the work table 40 always has the same position and orientation. At this time, the tool coordinate system information of the robot 20 is stored in the teaching data storage unit 75.

The third step is the step of holding the inserted part (S1-3). Like the gripping of the insert P1, the robot 20 approaches the inserted part P2 on the pallet 32 through direct teaching by the operator. Thereafter, the operator operates the robot gripper 22 to hold the part to be inserted P2. As shown in FIG. 9, unlike the insertion part P1, the inserted part P2 may have an uneven side surface of the part, which may result in an inconsistent gripping center point. This acts as a factor (holding error) that impedes regeneration after initial teaching, but can be resolved by robot path correction through additional teaching by the operator. The robot tool coordinate system information and robot gripper 22 operation information up to the end of the gripping are stored in the teaching data storage unit 75.

The fourth step is the inserted part moving step S1-4. The robot 20 moves to an arbitrary insertion ready position as shown in FIG. 10 through direct teaching by the operator in the state where the part to be inserted P2 is held by the robot gripper 22 (the two parts are in a non-contact state). ). In this case, the movement characteristic of the robot 20 is required to reduce the overall tact time by a high speed movement for quickly moving the inserted part P2 to a desired position rather than the precise movement required when the inserted part P2 is inserted into the inserted part P1.

In the general mechanical admittance relation, a larger external force is needed to increase the speed. However, an embodiment of the present invention proposes a method of converting into an admittance parameter suitable for the current working state as shown in Equation (1) below. This method allows the operator to change the speed of movement of the robot according to the teaching range. Robot tool coordinate system information of the position movement process is stored in the teaching data storage unit 75.

(1)

(One)

: 고속 운동을 위한 목표 어드미턴스 파라미터here,

: Target admittance parameter for high speed exercise

: 정밀 운동을 위한 목표 어드미턴스 파라미터

: Target Admittance Parameter for Precision Movement

:작업자의 외력

External force of worker

:작업자의 외력 증폭비

: External force amplification ratio of worker

The fifth step is the primary contact step (S1-5). As shown in FIG. 11, the height from the ground to the tip of the inserted part P2 is in close contact with the bottom surface of the inserted part P1 and the bottom surface of the inserted part P2 through direct teaching by the operator. It is obtained from the information of the robot tool coordinate system in the state of making. At this time, the contact state of the two parts (P1, P2) can be confirmed by the contact force generation of the monitoring unit 80, and stores the robot tool coordinate system information until the contact is completed in the teaching data storage unit 75.

방향으로 이동시켜 홀의 입구 가장자리가 펙의 상단면 가장자리와 접촉되게 한다(2점 접촉). 두 부품 간 접촉 여부는 모니터링부(80)의 접촉력 표시 창을 통해 판단하며 모든 접촉이 완료될 때까지의 로봇 툴 좌표계 정보를 교시 데이터 저장부(75)에 저장한다.The sixth step is the secondary contact step (S1-6). After the first contact step S1-5, the worker rotates the robot about the X axis of the tool coordinate system so that the hole of the inserted part P2 can be seen from the front side, as shown in FIG. 12. Thereafter, the worker moves the robot so that the inlet edge of the hole of the inserted part P2 is in two-point contact with the side and top edges of the peck, respectively, as shown by the eye A of FIG. 12. In this case, as shown in FIG. 13, first, the inlet edge of the hole is approached to the side of the peck to make contact, and then the inserted part is removed.

Direction so that the inlet edge of the hole is in contact with the top edge of the peck (two point contact). The contact between the two parts is determined through the contact force display window of the monitoring unit 80 and the robot tool coordinate system information until all the contact is completed is stored in the teaching data storage unit 75.

The number of contact points between the two parts P1 and P2 is determined from the rotation angle of the robot tool coordinate system as shown in FIG. Therefore, the robot tool coordinate system rotation angle required to perform the proposed two-point contact is calculated through the diameter of the peck and the hole D _p , D _h (or the tolerance c of the hole) as shown in Equation (2) below, and the monitoring unit 80 ) Is displayed in the teaching target display window.

(2)

(2)

방향으로 이동시킨 후

축을 기준으로 피삽입 부품(P2)을 θ만큼 회전시킨다. 피삽입 부품(P2)을 회전시킬 때 두 부품(P1, P2) 간 기구학적 분석(도 15)에 의한 정합이 이루어진 상태의 로봇 툴 좌표계 정보가 모니터링부(80)의 교시 목표 표시 창에 표시되고, 작업자는 현재 로봇 툴 좌표계 정보를 그 정보와 일치하도록 교시 작업을 수행한다. 정합 단계(S1-7)가 완료될 때까지의 로봇 툴 좌표계 정보를 교시 데이터 저장부(75)에 저장한다.The seventh step is the matching step (S1-7). The front end surface of the peck is located in the inner space of the hole, the front end surface and the bottom surface of the hole is parallel to each other and the center axis of the peck and the center axis of the hole are also defined as a matching step in the present invention (Fig. 14). In order to reach the mating stage, the operator inserts the inserted part P2 so that the leading edge of the peg and the inlet edge of the hole are separated from each other.

In the direction

The inserted part P2 is rotated by θ about the axis. When rotating the inserted part P2, the robot tool coordinate system information of the state where the registration by the kinematic analysis (Fig. 15) between the two parts P1 and P2 is made is displayed on the teaching target display window of the monitoring unit 80. The operator then teaches the current robot tool coordinate system information to match that information. The robot tool coordinate system information until the matching step S1-7 is completed is stored in the teaching data storage unit 75.

축을 기준으로 θ만큼 회전시켜 정합 상태의 위치 벡터로 변환시키는 식이다.Equation (3) calculates the position vector from the rotation axis center O point expressed in the {R ₃ } coordinate system to the robot tool coordinate system in the secondary contact state.

This is an equation that converts the position vector of the matching state by rotating by θ about the axis.

(3)

(3)

(4)

(4)

: 첫 번째 펙의 접촉점 좌표계 {R₂}의 X축 방향으로 Z축과 로봇 툴 좌표계 {T₂}의 Z축까지 거리here,

: Distance from the Z axis to the Z axis of the robot tool coordinate system {T ₂ } in the X axis direction of the contact point coordinate system {R ₂ } of the first peck

: 첫 번째 홀 좌표계 {H₁}의 Y축 방향으로 Z축과 로봇 툴 좌표계 {T₂}의 Z축까지 거리

: Distance in the Y direction of the first hole coordinate system {H ₁ } to the Z axis and to the Z axis of the robot tool coordinate system {T ₂ }

: 첫 번째 홀 좌표계 {H₁}의 Z축 방향으로 Y축과 로봇 툴 좌표계 {T₂}의 Y축까지 거리

: Distance in Y direction of the first hole coordinate system {H ₁ } to the Y axis and the Y axis of the robot tool coordinate system {T ₂ }

: 펙과 홀의 지름

: Diameter of peck and hole

: 홀의 깊이

: Depth of hole

The displacement value between the two position vectors derived through Equations (3) and (4) is expressed as the displacement of the robot tool coordinate system that changes when the second contact step is changed from the second contact step to the matching step as shown in Equation (5) below.

(5)

(5)

는 2차 접촉시 로봇 툴 좌표계 X,Y,Z 방향 위치 성분here,

Is the position component of the robot tool coordinate system in the X, Y, and Z directions for the second contact.

는 정합 단계의 로봇 툴 좌표계 X,Y,Z 방향 위치 성분

Is the position component of the robot tool coordinate system in the registration phase in the X, Y, and Z directions.

Therefore, the robot tool coordinate system in the matching step (S1-7) first calculates the displacement amount of the equation (5) in the robot tool coordinate system position component of the second contact step (S1-6) in the case of the position component as shown in equation (6) below. It is the sum of the values, and the bearing component is the same as the bearing component of the robot base coordinate system. The constant δ in the position Z-axis position component is the distance between the leading edge of the peg and the inlet edge of the hole, and this value is arbitrarily determined as long as unnecessary contact does not occur during rotation.

(6)

(6)

The last step of the initial teaching is the insertion step (S1-8). The operator inserts the inserted part P2 into the inserted part P1 through the teaching operation, as shown in FIG. Upon insertion, the contact force generated in the insertion direction (robot tool coordinate system -Z axis) is observed by the monitoring unit 80 to determine the insertion end position. The robot tool coordinate system information until the insertion step (S1-8) is completed is stored in the teaching data storage unit 75.

Next, the embodiment of the regeneration assembly step S2 and the further teaching correction step S3 will be described step by step.

First, as a preparation step of the reproduction assembling step S2, the stored teaching data information is converted into a robot operation command signal, and the robot operation command is reproduced by switching to the reproduction mode.

The first step is the step of holding the inserted part by regeneration (S2-1). The first operator returns the robot to its initial position and selects the working mode as the regeneration mode. Accordingly, the robot 20 approaches the insertion part P1 placed on the pallet 31 along with the stored teaching data (robot tool coordinate system information) and then grips the insertion part P1 by the robot gripper 22 operation information. .

The second step is the insertion part moving step (S2-2) by regeneration. The robot 20 moves the inserted part P1 gripped to the workbench 40 while the robot tool coordinate system tracks the data stored through the operator's direct teaching work, and then moves the insert part P1 to the workbench 40 through the gripper operation. ) On the top. As with the teaching work, the positioning and fixing device 41 on the work bench 40 ensures that the insert P1 placed on the work bench 40 always has the same position and orientation.

The third step is the step of holding the inserted part by regeneration (S2-3). The work content is the same as the insertion part grip by the said regeneration. Fig. 17 shows the gripping error (different gripping center point) generated when gripping the inserted part P2 having an uneven side. This error, judged by the parallel observer, is expressed as the amount of displacement of the robot tool coordinate system between the initial teaching and the robot regeneration, and is used to calibrate the robot's motion path (robot tool coordinate system information) at all subsequent regeneration stages. That is, as shown in FIG. 18, first, the robot tool coordinate system displacement amount is calculated and the displacement amount is added to the robot movement path stored during the initial teaching operation (Equation (7)).

(7)

(7)

If the orientation of the robot tool coordinate system is changed, the orientation change amount derived in the same manner is used for correcting the orientation of the robot tool coordinate system in a later regeneration step (Equation (8)).

(8)

(8)

The fourth stage of the robot regeneration is the movement of the inserted part by regeneration (S2-4). The robot 20 arrives at the insertion ready position along the robot movement path corrected in the insertion part gripping step S2-3. The coordinate value reached by the actual robot tool coordinate system is a value obtained by adding the coordinate system displacement value (or azimuth change amount) to the data stored during the teaching work as shown in Equation (9) below.

(9)

(9)

The fifth step of robot regeneration is the primary contact step (S2-5) by regeneration. As the robot moves along the stored path, contact occurs between the inserted part P2 and the inserted part P1. If no contact occurs or if the robot continues to operate after contact, the impedance controller (Eq. 10) of FIG. 19 prevents damage between the two parts and system damage.

(10)

(10)

here,

: 각각 최초 생성된 목표 경로의 위치 벡터, 컴플라이언스 경로의 위치 벡터

: Position vector of target path and initial vector of compliance path

는 두 부품 간 접촉시 접촉력이 작용할 때 위치 변화를 나타내는 임피던스 파라미터

Is an impedance parameter representing the change in position when a contact force is applied during contact between two components.

Proper impedance parameter selection can result in satisfactory compliance behavior when contact between two parts occurs, but this parameter sometimes results in poor tracking accuracy of the target position and orientation in the absence of contact between the two parts. In order to solve this problem, the present invention includes an impedance controller including a position controller.

In other words, the acceleration α used to calculate the target torque by general inverse dynamic analysis as shown in Equation (11) below is calculated using Equation (12) designed to follow the position and velocity of the compliance coordinate system (path).

(11)

(11)

(12)

(12)

here,

: 실제 이동한 로봇의 위치 벡터

: Position vector of the robot actually moved

On the other hand, when the problem occurs during the primary contact step (S2-5) in the regeneration assembly step (S2), the alarm lamp 84 of the monitoring unit 80 is operated through the parallel observer of FIG. It stops automatically. Thereafter, the operator converts the work mode of the monitoring unit 80 to the teaching work mode and then performs additional teaching work. The teaching force information of the worker generated through this operation is transmitted to the teaching data correction unit 77 and used to correct the movement path and the motion characteristic of the robot previously stored.

는 식(7)로부터 보정된 1차 접촉 단계의 로봇 툴 좌표계를 나타내고,

는 작업자의 추가 교시에 의한 좌표계와 보정된 좌표계 사이의 변위값으로 이후 단계의 로봇 경로 좌표계 보정시 사용된다. 따라서,

는 최종적으로 보정된 1차 접촉 단계의 로봇 툴 좌표계를 의미한다. 만약, 로봇 툴 좌표계의 방위가 변경되었다면 똑같은 방법으로 방위 보정값을 도출하여 로봇 경로 좌표계 보정 시 사용한다(식 (14)).As with the teaching work, the operator observes the reaction force generated in the Z-axis in real time and teaches the robot to make a desired contact (contact between two parts). After the contact between the two parts is completed, the robot tool coordinate system information corrected from equations (7) and (8) is compared with the current robot tool coordinate system information to derive a new displacement value as shown in equation (13) below, and then play it back. Apply to the step. here,

Denotes the robot tool coordinate system of the first contact step corrected from equation (7),

Is the displacement value between the coordinate system and the corrected coordinate system by further teaching of the operator, and is used for the robot path coordinate system correction in a later step. therefore,

Denotes the robot tool coordinate system of the first corrected contact stage. If the orientation of the robot tool coordinate system is changed, the orientation correction value is derived in the same way and used to calibrate the robot path coordinate system (Equation (14)).

(13)

(13)

(14)

(14)

The sixth step of robot regeneration is the second contact step by regeneration (S2-6). The robot rotates and moves the inserted part P2 according to the stored robot tool coordinate system information during the initial teaching work so that the inlet edge of the hole of the inserted part P2 is in contact with the side and top edges of the peck, respectively. If the contact between the two parts does not occur due to the regeneration operation or the robot continues to operate after the contact, the alarm lamp 84 of the monitoring unit 80 is operated through the parallel observer of FIG. 19 as in the previous step, and the regeneration operation is performed. This stops automatically. After this, the operator converts the working mode of the monitoring unit 80 to the teaching work mode and then performs additional teaching work. The teaching force information of the worker generated through this operation is transmitted to the teaching data correction unit 77 and used to correct the movement path and the motion characteristic of the robot previously stored.

The seventh step of robot regeneration is the registration step by regeneration (S2-7). The inserted part P2 is moved and rotated according to the stored robot's path in the direct teaching of the operator, so that the top surface of the peck and the bottom surface of the hole are parallel to each other, and the center axis of the peck and the center axis of the hole are parallel to each other. . When unnecessary contact or interference between the two parts is caused by the regeneration operation, the alarm lamp 84 of the monitoring unit 80 is operated through the parallel observer of FIG. 19 as in the previous step, and the regeneration operation is automatically stopped. After this, the operator converts the working mode of the monitoring unit 80 to the teaching work mode and then performs additional teaching work.

The final step of the robot regeneration is the insertion step by regeneration (S2-8). By the regeneration operation, the robot moves the inserted part P2 to the stored position in the initial teaching operation (the contact between the parts occurs at the moment when the movement is completed and the contact force occurs within a certain limit). However, if the contact force does not occur even after the movement is completed, or if a contact force greater than a certain limit occurs between the parts during the movement of the parts, the alarm lamp 84 of the monitoring unit 80 is operated through the parallel observer of FIG. 19 as in the previous step. The playback operation stops automatically. After this, the operator converts the working mode of the monitoring unit 80 to the teaching work mode and then performs additional teaching work.

The present invention can be applied throughout the industry through organic compatibility with the medical, defense, and construction sectors, and the internationalization of related technologies is at an early stage. You can expect

10: worker 20: robot
21: Force / Torque Sensor 22: Robot Gripper
23: encoder 31, 32: pallet
33, 34, 41: positioning and fixing device 40: worktable
50: conveyor 60: interface
70: collaborative system controller 71: robot path and motion characteristics
72: impedance controller 73: position controller
74: robot drive unit control unit 75: teaching data storage unit
76: teaching data playback section 77: teaching data correction section
80: monitoring unit 100: human-robot collaboration system

Claims (16)

As a part assembly method based on a human-robot collaboration system for assembling parts through a robot,
An initial teaching assembly step of storing the position and operation information of the robot while operating the robot to perform assembly of parts by direct teaching of an operator;
A regeneration assembly step of automatically assembling parts based on the stored position and motion information of the robot; And
In addition, when the assembly error of the parts occurred in the regeneration assembly step, the operator further teaches to correct the position and motion information of the robot, further comprising:
The component is a human-robot collaboration system-based component assembly method characterized in that it comprises an insertion part having one or more pegs, and an insertion part is formed in which one or more holes into which the pegs can be inserted. . delete The method of claim 1,
The initial teaching assembly step,
An insertion part gripping step of gripping the insertion part after registering the coordinate system of the initial robot posture, and storing the position and motion information of the robot until the operation completion time;
An insert part moving step of moving the gripped insert part and placing it on the workbench, and storing the position and motion information of the robot until the completion of the operation;
A part to be inserted, which holds the part to be inserted and stores the position and motion information of the robot until the completion of the operation;
An inserted part moving step of moving the gripped inserted part over the inserted part placed on the work table and storing the position and the motion information of the robot until the completion of the operation;
A part insertion preparation step of contacting the inserted part with the inserted part to match the peck of the inserted part with the hole of the inserted part, and storing the position and the motion information of the robot until the completion of the operation; And
And inserting a part of the inserted part into the hole of the inserted part to determine an insertion end position and inserting a part to store the position and motion information of the robot until the completion of the operation. How to assemble system based parts. The method of claim 3,
The component insertion preparation step,
A primary contact step of holding the inserted part in close contact with the inserted part to determine a position of the inserted part;
A second contact step of rotating the inserted part about an imaginary axis, wherein each of both edges of the inlet of the hole of the inserted part generates two-point contact with the side and front end edges of the peck of the inserted part; And
By moving the inserted part such that the contact between the leading edge of the peg of the inserted part and the inlet edge of the hole of the inserted part is dropped, and then rotating the inserted part in a direction opposite to the rotation direction in the second contact step. The front end surface of the peg of the insert is located in the inner space of the hole of the inserted part, and the front end surface of the peg and the bottom surface of the hole are parallel to each other, and the center axis of the peg and the central axis of the hole are also parallel to each other. Human-robot collaboration system based component assembly method comprising the step of matching. The method according to claim 3 or 4,
The component insertion preparation step and the component insertion step,
A method for assembling parts based on a human-robot collaboration system, wherein an operator can perform a teaching operation while checking a contact force between an inserted part and an inserted part. The method according to claim 3 or 4,
The regeneration assembly step,
The insertion part holding step, the insertion part moving step, the insertion part holding step, the insertion part moving step, the part insertion preparation step and the part based on the position and operation information of the robot stored in the initial teaching assembly step Play the insertion step sequentially,
It is determined whether the position and motion information of the robot of each stage to be reproduced matches the information taught in the initial teaching assembly stage, and stops the reproduction assembly stage if the mismatch error exceeds the set error. How to assemble parts based on a collaborative system. The method according to claim 6,
The additional teaching correction step,
If the regeneration assembly step is stopped, the operator performs additional teaching to correct the position and operation information of the robot,
A method for assembling parts based on a human-robot collaboration system, comprising correcting a robot's motion command signal corresponding to all regeneration assembly steps after the robot's position and motion information changed by additional teaching. The method of claim 3,
A method for assembling parts based on a human-robot collaboration system, characterized by further storing the coordinate system information of the robot in consideration of the distance between the first gripped part and another part in order to hold a plurality of parts on a pallet. The method of claim 3,
Change the robot's movement characteristics to high speed or precision motion by changing the admittance parameter for the current job according to the operator's teaching range.
And a observer automatically changes the admittance parameter. 5. The method of claim 4,
The rotation angle of the inserted part is determined through the diameter of the peck of the inserted part and the hole of the inserted part,
Human-robot collaboration system based component assembly method, characterized in that the contact between the inserted part and the inserted part is determined from the contact force signal of the monitoring device. The method of claim 1,
Position controller to prevent component breakage and system damage when contact occurs between parts during the initial teaching assembly step, regeneration assembly step, and additional teaching correction step, and to improve path tracking performance of the robot when no contact phenomenon occurs. Component assembly method based on the human-robot collaboration system, characterized in that using an impedance controller having a. A robot capable of gripping and moving parts;
An interface capable of transmitting a command of a worker to a robot or delivering external environment information to a worker at work;
An encoder capable of identifying position information of the robot; And
A cooperative system controller capable of performing the robot in an initial teach mode, a play mode, and an additional teach correction mode,
The initial teaching mode is a mode for storing the position and operation information of the robot while operating the robot by performing direct assembly of the operator when assembling the first part to perform assembly of the parts,
The regeneration mode is a mode for automatically assembling parts based on the information of the robot stored in the initial teaching mode,
The additional teaching correction mode is a mode in which an operator additionally teaches and corrects the position and motion information of the robot when an assembly error of a component occurs in the regeneration mode.
The collaboration system controller,
A robot path and motion generation unit for determining a path and a motion characteristic of the robot through the teaching force information of the worker;
A robot driving device control unit for converting the path and motion characteristic information of the robot into a robot synchronization signal and then transmitting the robot driving device to the robot driving device;
A teaching data storage unit for storing the position and motion information of the robot by the first teaching or additional teaching of the operator;
A teaching data correction unit for correcting stored information through additional teaching of an operator; And
Human-robot collaboration for assembly of parts comprising a teaching data reproducing unit for converting the information transmitted to the teaching data storage unit or the teaching data correction unit to various signals to be followed by the robot in the reproduction mode of the robot; system. delete The method of claim 12,
The collaboration system controller,
An impedance controller for redefining the path and motion characteristics of the robot through the contact force information and the impedance parameters of the parts in the inter-part contact situation; And
A human-robot collaboration system for assembling parts, further comprising a position controller for compensating for the path following performance degradation of the robot generated in a non-contact situation. The method of claim 12,
The collaboration system controller,
The robot's present, such as a switch for returning the robot to its initial position, a robot gripper ON / OFF switch for gripping the workpiece, a switch for selecting the teaching mode and the regeneration mode, an alarm for an emergency situation during the regeneration mode, and the like. Monitoring including window displaying job status by robot's movement characteristics, operator's teaching power, contact force generated when contacting parts, tool coordinate system of working robot and tool coordinate system of robot to be reached A human-robot collaboration system for assembling parts, further comprising a part. The method of claim 12,
And a multi-axis force / torque sensor for measuring the teaching signal of the operator.

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