KR20040052426A - Direct teaching apparatus with two force sensors and it's method for robot path generation on the free surface - Google Patents

Abstract

PURPOSE: A direct teaching device and method with a double force-torque sensor for generating robot path on the free surface is provided to precisely perform the work of a robot by stably securing data about the free surface of a vehicle body. CONSTITUTION: A direct teaching device is composed of a robot(1) having a robot controller(7), a direct teaching unit(3) mounted to the robot and contacted with the free surface, and a main controller(5) connected to the robot. The robot controller includes a robot control program(11) and an operation program(9). The direct teaching unit is controlled by the operation program, moves on the free surface, and generates position data. The main controller receives the position data through the robot, processes the position data with a data processing program(13), and has a control program(5) for performing communication with the robot controller.

Description

DIRECT TEACHING APPARATUS WITH TWO FORCE SENSORS AND IT'S METHOD FOR ROBOT PATH GENERATION ON THE FREE SURFACE}

The present invention relates to a direct teaching apparatus of the robot and a method thereof, and more particularly, when the teaching operation is performed by providing a force-torque sensor and a shock absorbing apparatus, the working data on a free-form surface can be easily obtained. In addition, the present invention relates to a direct teaching apparatus and a method of directing a robot capable of performing a task efficiently by such work data.

In general, in the case of performing heat treatment work on the surface of the press die, or painting, welding, etc. on the vehicle body, the work was performed by various methods.

As an example of such a task, a method by an operator, a method by CAD / CAM, a method by a robot, and the like are presented.

When the work is performed by the worker, for example, when the heat treatment work on the surface of the mold, the heat treatment work is performed by the worker using the heat treatment mechanism directly, the quality of heat treatment is changed according to the skill of the worker, There is a problem that damage factors such as cracking of the mold due to boiling heating of the mold surface occur.

In addition, when working with NC or CAD / CAM, work paths require a lot of complicated work elements, and paths are also difficult to create. And, in the case of a work that is present in a variety of work, there is a problem that automation by the robot is difficult because it requires the CAD data of the object in the field.

Therefore, the present invention has been created to solve the above problems, the object of the present invention by applying a robot that can automatically perform the teaching work, by stably obtaining data on the free surface, such as the vehicle body It is to provide a direct teaching device and a control method of the robot that can accurately perform the work of the robot.

In addition, another object of the present invention is to maintain a constant moving speed of the teaching mechanism and a constant distance from the object by direct teaching device of the robot that can obtain accurate teaching data in a single operation without trial and error of teaching work And a control method thereof.

Still another object of the present invention is to provide a teaching force-torque sensor and a load detector, thereby directly instructing a robot and a method of controlling the robot capable of preventing damage caused by a collision of an object, a teaching device, and a robot that may occur during teaching. To provide.

Still another object of the present invention is to distinguish between the non-contact approach path and the contact work path during the teaching work, to maintain the speed in the work path, to maintain the distance to the free surface by the direct teaching program, so that the work can be easily performed. The present invention provides a direct teaching apparatus for a robot and a control method thereof.

1 is a block diagram showing the configuration of a direct teaching robot system according to a preferred embodiment of the present invention.

FIG. 2 is a schematic side view of the teaching apparatus shown in FIG. 1. FIG.

FIG. 3 shows another preferred embodiment of the teaching instrument shown in FIG. 2.

FIG. 4 is a partially enlarged perspective view illustrating an enlarged cage frame of the teaching apparatus shown in FIG. 3.

FIG. 5 is a flowchart of a teaching operation of the direct teaching robot system shown in FIG. 1.

FIG. 6 is a flowchart illustrating a sequence of an operation program in which the robot controller shown in FIG. 1 directly operates a robot during teaching.

<Explanation of symbols for main parts of drawing>

1: robot 3: direct teaching equipment

20: force-torque sensor 22: shock absorbing member

24: teaching handle 30: contact end

In accordance with an embodiment of the present invention for achieving the object as described above, the direct interrogator is a robot provided with a robot controller in which a robot control program and an operation program are embedded, mounted on the robot and in contact with a free-form surface. And a direct teaching mechanism that is controlled by an operation program to generate position data by touching and moving on a free curved surface. And connected to the robot receives the position data generated directly from the teaching mechanism through the robot to process by a data processing program, and a control program for communicating with the robot controller is embedded to control to perform the teaching work Provides direct instructional values that include the main controller.

Hereinafter, with reference to the accompanying drawings will be described in detail a direct teaching system of a robot according to a preferred embodiment of the present invention.

As shown in FIG. 1, the direct teaching system of the robot proposed by the present invention includes a robot 1 and a direct teaching mechanism 3 mounted on the robot 1 to generate position data by moving along a free curved surface. And a main controller 5 connected to the robot 1 to receive position data generated from the teaching device 3 directly through the robot 1 and to control the robot 1 based on the position data. Include.

In the direct teaching system of a robot having such a structure, the robot 1 has a robot controller 7 therein to input and output data to and from the main controller 5 and the direct teaching mechanism 3. Will do the work.

In more detail, the robot controller 7 receives the data from the direct teaching mechanism 3, calculates a movement position, and moves the end of the robot 1 to the movement program 9, and the main controller 5. A robot control program 11 having a communication function for receiving and executing a control command transmitted from the robot 1 and transmitting the position data of the robot 1 to the main controller 5 is provided.

In addition, the main controller 5 is responsible for communicating with the data processing program 13 and the robot controller 7 which store the path traveled by the robot 1 at regular intervals and generate a work program based thereon. It consists of the control program 15 to perform.

Therefore, the direct teaching robot 1 system having the structure as described above allows the operator to directly hold the teaching mechanism 3 and move the teaching mechanism 3 directly along a predetermined work line on a free curved surface such as a vehicle body. Create The generated position data is transmitted to and stored in the main controller 5, and the main controller 5 executes calculation based on the position data, and controls the robot 1 based on the calculated value to actually perform heat treatment, painting, etc. Will do the work of.

Meanwhile, the direct teaching mechanism 3 is shown in FIG. 3, and as shown, a force-torque sensor 20 provided at an end of the robot 1 to sense a moving direction and torque of the direct teaching mechanism 3. ), A shock absorbing member 22 mounted on the lower portion of the force-torque sensor 20 to absorb external shocks, and mounted on a lower portion of the shock absorbing member 22, for teaching and moving by an operator. And a contact end 30 for detecting a contact force between the handle 24 and the free curved surface.

In the direct teaching mechanism 3 having such a structure, the force-torque sensor 20 can detect forces and torques in six directions.

Therefore, when the operator grasps the teaching handle 24 and moves the teaching mechanism 3 directly, the force-torque sensor 20 detects this and transmits it to the robot controller 7.

The shock absorbing member 22 includes a material having a suitable elastic force, preferably a spring. Therefore, the teaching mechanism 3 directly absorbs the shock generated while moving in contact with the free curved surface.

The teaching handle 24 serves to directly move the teaching mechanism 3 by the user holding the teaching handle 24 when performing the teaching work.

These teaching knobs 24 are equipped with operation switches 26 and teaching data storage switches 28, respectively. The operation switch 26 causes the main controller 5 and the robot controller 7 to be moved by the user holding the teaching mechanism 3 directly to the work position and pressing the operation switch 26 to start the teaching operation. Recognize teaching work.

And, the teaching data storage switch 28 is the teaching data storage switch when a user directly grasps the teaching mechanism 3 and reaches the teaching start position and then contacts the contact end 30 with a free-form surface to start teaching work. Pressing (28) causes the main controller 5 and the robot controller 7 to recognize the start of the teaching data storage operation.

A contact end 30 is provided at the lower end of the teaching handle 24. The contact end 30 is equipped with a load detector 76 capable of detecting a contact force by contacting a free curved surface such as a vehicle body during teaching work.

Therefore, during the teaching operation, the load detector 76 detects the contact force of the contact end 30 in contact with the free curved surface, thereby preventing the contact end 30 from being damaged by contacting the free curved surface with excessive force.

That is, when the contact end 30 contacts the free curved surface with a force of a predetermined value or more, the teaching device 3 can be prevented from being directly damaged by moving the robot 1 in the vertical direction and stopping the program.

On the other hand, a direct teaching mechanism according to another preferred embodiment of the present invention is shown in Figs. The direct teaching mechanism 60 shown in FIGS. 4 and 5 has a cage 32 to prevent contact force from acting on the force-torque sensor 64 during the teaching operation by contacting on a free-form surface. To be fitted.

This direct teaching mechanism 3 provides a shock absorbing member 62 at the end of the robot and a cage frame 32 at the bottom of the shock absorbing member 62. Then, the load detector 76 is mounted to the lower portion of the cage frame 32, and the contact end 74 is provided to the lower portion of the load detector 76.

Therefore, when the teaching operation is performed on the free curved surface using the direct teaching mechanism 60, the contact end 74 is in contact with the free curved surface, and the contact force is detected by the load detector 76 at this time.

In addition, a cage-shaped frame 32 is provided to prevent the force-torque sensor 64 from being broken by the excessive contact force acting on the contact end 74 and acting on the force-torque sensor 64. .

The cage frame 32 has an upper plate 34 mounted below the shock absorbing member 64, a lower plate 36 mounted above the load detector 76, the upper plate 34 and a lower plate. And a connecting bar 38 connecting the 36 with each other.

Therefore, the contact force transmitted through the contact end 30 is transmitted to the cage frame 32 through the load detector 76, the cage frame 32 is also mounted to the shock absorbing mechanism 62 The contact force is finally absorbed by the shock absorbing mechanism 62. As a result, no contact force is transmitted to the force-torque sensor 64, thereby enabling stable operation.

The teaching handle 66, the switches 68, 72, and the like, which are mounted on the force-torque sensor 64, have the same structure as the above-described embodiment, and thus will be omitted below.

FIG. 5 is a flowchart illustrating a process of performing a teaching operation by a direct teaching mechanism having the above structure.

As shown, power is supplied to the system (S100), and the control program 15 of the main controller 5 and the robot control program 11 of the robot controller 7 are executed (S110).

When the robot control program starts to be executed (S120), the operator presses the operation switch 26 attached to the end of the robot 1, grabs the teaching mechanism 3, and applies an external force to move the robot 1 to the working position. (S130).

Then, when the teaching mechanism 3 reaches the vicinity of the free curved surface for teaching, the operator presses the teaching data storage switch 28 to switch to the teaching mode and starts teaching the work section (S140).

The teaching operation proceeds by bringing the contact end 30 into contact with the free-form surface and moving along the path where the work is to proceed.

In this teaching process, the motion program 9 of the robot 1 receives the output value of the force applied to the force-torque sensor 20 to calculate the micro displacement of the robot 1 and moves on a free-form surface. The microrotational displacement of the robot 1 is calculated from the rotational moment of the sensor generated. Then, the teaching operation is performed by moving the robot 1 by this result.

6 shows in detail the process of the teaching operation is performed by the operation program of such a robot (1). As shown, first, when the operation program 9 is started, data is acquired by the force-torque sensor 20. Then, it is determined whether the contact force is excessive by the contact end 30. If it is determined that the contact force is excessive, the robot 1 is moved to the upper safety zone and stopped.

If the contact force is not excessive, the operation switch is judged to be ON / OFF so that the robot 1 does not operate when it is OFF, and when it is ON, it is determined whether the teaching data storage switch 28 is ON.

As a result of determination, when it is in the ON state, it is recognized as a teaching operation and the low speed movement mode is executed. That is, the teaching mechanism 3 performs fine operation by multiplying the resultant value of the micro displacement and the micro rotation displacement obtained from the force-torque sensor 20 with a low constant, and when off, increases the constant value to enable rapid movement. do.

In addition, the force applied to the free curved surface of the load detector is measured to move slightly toward the free curved surface when low force is applied, and to move to the opposite side when the contact force is high, so that the contact force is kept constant.

On the other hand, in the OFF state, it recognizes that it is not a teaching operation and executes the high speed moving mode. Therefore, the work time can be shortened by preventing unnecessary movement of the robot 1 in the teaching work.

When the high speed and low speed movement modes are completed, the work is finished by converting the coordinate system and moving the robot 1.

Referring back to FIG. 5, the teaching work is performed through the above process.

While the teaching operation is in progress, the communication program of the robot controller 7 receives a position signal of the end of the robot 1 and a status signal of the teaching data storage switch at predetermined time intervals and transmits the signal to the main program.

When the teaching work is completed (S150), the operator terminates the teaching work by turning off the teaching data storage switch 28 and the operation switch 26.

In addition, the main controller 5 stores the input data during the teaching work, and after the teaching work is finished, divides the position data at regular intervals and processes the work program containing the path that the robot 1 must pass at a constant speed during the work. To generate (S160).

During the work path data generation operation, data is generated at different intervals between the transport path in the free space and the contact work path on the free surface, and the robot 1 passes the speed for two intervals by passing it for a predetermined time interval. It can be adjusted appropriately.

In addition, the main controller 5 stores the data received from the robot 1 controller, and divides the taught position data by a predetermined interval to pass the taught path during the operation within a certain time to make the operation speed constant.

And, by deleting overlapping data among stored data, the operation is prevented from being stopped in the middle, and the interval can be adjusted by simple input so that the operator can work efficiently at various speeds in the field and work on the main controller. The program is saved so that you can do the previous work again after another path has been taught.

As described above, the direct teaching apparatus and the method according to the present invention have the following advantages.

First, by using the conventional CAD data or the robot pendant device can be automated by the robot directly in the field, it is possible to improve the precision, performance, and quality accordingly.

Second, even if the work object changes, the operator simply needs to specify the teaching path by simply holding the robot directly, and thus has excellent applicability to various tasks.

Third, since the taught data is stored in the main controller, the taught tasks can be executed again at any time, and the operator can adjust the interval at the time of data processing, thereby securing a variety of tasks.

Fourth, it is possible to separate the force information and the contact force information by the operator's intention by attaching a force-torque sensor for detecting the intention of the operator to the teaching mechanism, and attaching a load detector for detecting only the contact load at the contacting end. Stability at the time of contact can be ensured.

Fifth, since a method for protecting the sensor and the object is provided in the robot's operation program, safer teaching operation is possible, and the shortening of the teaching time can reduce the overall process time.

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

Claims (11)

A robot provided with a robot controller in which a robot control program and an operation program are embedded; A direct teaching mechanism mounted on the robot and in contact with a free curved surface and controlled by the operation program to generate position data by touching and moving on the free curved surface; And The main unit is connected to the robot and receives the position data generated from the teaching device directly through the robot, processes the data by a data processing program, and a control program for communicating with the robot controller is embedded to control the teaching operation. Direct teaching device including a controller. The apparatus of claim 1, wherein the direct teaching mechanism is provided at an end of the robot to directly detect a moving direction and torque of the teaching mechanism, and is mounted below the force-torque sensor to absorb external shocks. Direct teaching apparatus comprising a shock absorbing member, a teaching handle mounted on the lower portion of the shock absorbing member to be gripped and moved by a worker, and a contact end for detecting a contact force with a free curved surface. According to claim 1, The direct teaching mechanism is mounted on the end of the robot shock absorbing member for absorbing shock, the cage frame mounted to the lower portion of the shock absorbing member, the force mounted in the cage frame A direct sensor comprising a torque sensor and a teaching handle, a load detector mounted under the cage frame, and a contact end mounted under the load detector. The direct teaching apparatus of claim 3, wherein the cage frame comprises an upper plate mounted on the lower portion of the shock absorbing member, a lower plate mounted on an upper portion of the load detector, and a connection bar connecting the upper plate and the lower plate to each other. A direct teaching apparatus according to claim 2 or 3, wherein the force-torque sensor comprises a six-axis force-torque sensor. 4. The direct teaching apparatus according to any one of claims 2 to 3, wherein the teaching handle comprises an operation switch and a teaching data storage switch. The direct teaching device of claim 2, wherein the load detector comprises a three-axis load detector. The method of claim 1, wherein the main controller is divided into a contact section and a non-contact section in accordance with the on / off of the teaching data storage switch, and in the non-contact section to increase the transfer speed, and in the contact section to be transported in accordance with the working speed Direct teaching device. The method of claim 8, wherein in the contact section to divide the path interval to match the working speed in order to be transported to the working speed, and in the non-contact section by dividing the large interval to directly control the movement speed of the robot and direct teaching mechanism Teaching device. Executing a control program of the main controller and a robot control program of the robot controller; When the step is started, the operator presses an operation switch attached to the end of the robot, grabs the teaching mechanism, and applies an external force to move the robot to a working position; When the teaching apparatus reaches a near free surface for teaching, the operator presses the teaching data storage switch to switch to teaching mode and performs teaching of the working period; Receiving data inputted during the teaching operation from the robot controller at a predetermined time interval and receiving and transmitting the position signal of the end of the robot and the status signal of the teaching data storage switch to a main program; After completion of the teaching operation, turning off the operation switch and the teaching data storage switch; Direct teaching method comprising processing data stored in the main program and automatically generating a work program. 11. The method of claim 10, further comprising the steps of: acquiring data by a force-torque sensor when the operation program is started; Determining whether the contact force is excessive by the contact end, and if the contact force is determined to be excessive, moving the robot to a safe area above and stopping the robot; When the contact force is not excessive, determining whether the operation switch is ON / OFF so that the robot does not operate when OFF and determining whether the teaching data storage switch is ON when ON; In the determining step, in the case of the ON state, recognizing it as a teaching operation and executing a low speed moving mode; In the OFF state, recognizing that the teaching operation is not performed and executing the fast moving mode; And Direct teaching method of completing one task by converting a coordinate system and moving a robot when the high speed and low speed movement modes are completed.