KR100842088B1 - The automotive position measuring system on a continuously moving conveyor and method thereof - Google Patents

Abstract

In the present invention, the three-dimensional position and attitude change amount of the vehicle body that is placed on the hanger and is conveyed while the conveyor is still moving without stopping is measured by the sensing system, and the robot system performs the sealing or painting work finely by the corrected locus To a position measurement system and method thereof.

The position measuring system according to the present invention includes a visual device unit for measuring a three-dimensional position and an attitude change amount of the vehicle body through the measurement of the feature point position of the vehicle body, and a three-dimensional position and attitude change amount of the vehicle body measured by the visual device unit A plurality of robot system units to which a carriage for carrying out a car body UBS (Underbody Sealing) operation, an RPP (Rocker Panel Primer) and a Deadner painting operation is attached, And a central control unit for controlling the structures so that the vehicle body position is detected and the correction operation is sequentially performed by the robot through the communication with the visual system.

Position measuring system, Continuous conveyor, Stereo camera, Multi-joint robot

Description

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a continuous conveyor-based vehicle position measurement system and a method thereof,

1 is a block diagram showing an embodiment of a vehicle position measuring system on a continuous conveyor according to the present invention;

Description of the Related Art [0002]

10 - Continuous conveyor 12 - Hanger

13 - Distance measuring sensor 14 - Reflector

20 - Robot controller 21 - Travel axis

22 - Robot 24 - Camera

30 - Vision unit 31 - Central control unit

32 - LS

According to the present invention, the three-dimensional position and posture change amount of the car body being conveyed while being placed on the hanger even when the conveyor is moving without stopping is measured by the sensing system, and the robot can finely perform sealing or painting work by the corrected locus More specifically, a stereo camera is mounted on a plurality of articulated robot bodies to which a camera mounting stand and a traveling device are attached, and then transferred to a conveyor to enter the robot work space, Dimensional position and attitude change amount of the vehicle reference axis constituted by a plurality of vehicle body feature points by measuring the three-dimensional positions of the plurality of feature points on the basis of the pattern recognition and the stereo matching method for the feature points, To perform sealing and painting work with precision Designed to relate to the position measuring system and the measurement method.

In the conventional vehicle position measuring system, when a vehicle body enters a robot work space by a conveyor while being seated in an over-hanger hanger, in order to measure a stable body position by a sensing system and perform precise work by a robot, After hanging the conveyor by the centralized PLC control, the hanger is clamped by the clamping device which is additionally attached to the upper end of the conveyor in order to prevent the initial positioning of the body and the movement of the hanger.

The PLC waits for a certain period of time until the suspension of the hanger which is generated during the clamping process of the hanger is reduced, and then communicates with the robot system and the position measurement sensing system By moving the robot to the measured position of the car body feature point set by car type and calculating the 3-dimensional position and attitude change amount of the entered reference body axis through the 3-dimensional position measurement of the body feature point that the sensing system enters, The conveyor Go and Stop method, which is a method to operate the robot system in order to carry out the sealing and the painting work by the corrected trajectory, can be carried out sequentially.

As described above, in the case of the sealing and painting work by the conveyor go and stop method which is generally used conventionally, in order to measure the stable body position by the sensing system and precisely seal or paint the work by the robot, After clamping the hanger with the clamping device, it temporarily waits until the shaking phenomenon of the hanger caused by the clamping process is reduced, and then carries out the measurement of the position of the vehicle by the sensing system. Therefore, Under Body Sealing) is easy to work.

However, in the case of a conventional automobile paint line in which a sealing robot system by the above-described conveyor Go and Stop method is not built, a plurality of workers are seated on an over-hanger hanger by a plurality of workers while the conveyor is moving continuously, (UBS) is performed manually according to the UPH (Unit per Hour). Therefore, if the position measuring system for the UBS work by the above-mentioned conveyor Go and Stop method is applied to the automobile coating line, The continuous conveyor system installed should be converted into a conveyor which can be operated by go and stop system consisting of a clamping device for hanger positioning and flow prevention and a servo device capable of manual or automatic running control of hanger, It is necessary to have a construction cost, and in terms of production efficiency Since the UBS work has a lot of work area by the robot compared with other work, the robot has to wait for about 10 seconds without any work until the hanger shake after the temporary stop of the conveyor is reduced, which is a small burden on the shortening of the work cycle time of the robot And the like.

Therefore, when a worker carries out UBS work for a long period of time repeatedly, a worker may have a musculoskeletal disorder. Therefore, the automobile manufacturers who have built a body UBS robotic system based on the conveyor Go and Stop method described above , There is a study on whether UBS work on a car body that is seated on a hanger and transported without stopping the conveyor can be applied to a robot system.

In order to perform the UBS work of the car body on the continuous conveyor, there is a technical problem that must be solved in order to measure the three-dimensional position of a plurality of minutiae in the car body that are seated on the hanger on the continuous conveyor, Instantaneously acquires an image for a plurality of feature points so that a difference between a distance value between a plurality of vehicle body feature points and a distance value between the vehicle body feature points calculated by the sensing system in a state where the conveyor is stopped is within an allowable error range, An image processing technique capable of precisely calculating three-dimensional position information about a reference axis and a three-dimensional position and attitude change amount of an input body with respect to a reference body measured while the vehicle is moving, Corresponding to the conveyor surging phenomenon, the sealing locus is corrected The robot calibration techniques are required that allow you to perform sophisticated sealing operation.

It is an object of the present invention to instantaneously measure the three-dimensional position and attitude information of a plurality of minutiae in a moving body that is seated on an over hanging hanger on a continuously moving conveyor by using an image processing apparatus without temporarily stopping the vehicle body, The present invention provides a vehicle position measurement system that can smoothly perform UBS and painting operations of a vehicle body by a robot even on a continuous conveyor without temporarily stopping the vehicle body by the conventional method.

In order to achieve the above objects, according to the present invention, there is provided a continuous conveyor-based vehicle position measurement system,

A visual device unit for measuring a three-dimensional position and an attitude change amount of the vehicle body through the measurement of the characteristic point position of the vehicle body,

A carriage for carrying out a vehicle body UBS (Underbody Sealing) operation, an RPP (Rocker Panel Primer) and a Deadner painting operation using the three-dimensional position and posture change amount of the vehicle measured by the visual device unit, A plurality of robot system units to which the robot system is attached,

The control unit controls the structures so that the car body position measurement during moving and the correction operation by the robot sequentially proceed through communication with the visual device unit, A central control unit is provided.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a block diagram showing an embodiment of a vehicle position measuring system on a continuous conveyor according to the present invention.

1, a plurality of over hanging hangers 12 for transporting a vehicle body to a continuous conveyor 10 are provided.

An LS sensor 32 for receiving the vehicle type signal being conveyed and detecting the time of entry of the vehicle body is provided in the periphery of the continuous conveyor 10 and a reflector 14 is provided in each overhanging hanger 12.

In addition, the laser distance sensor, that is, the distance measuring sensor 13 is fixed to the upper end portion of the work space in a position and posture free from interference even when the over hanging hanger is moved, and the laser is emitted to the reflector 14, The distance information is measured and sent to the visual device unit 30 to be described later.

The visual device unit 30 is composed of three or more single cameras or a PC system in which a stereo camera and an image board capable of simultaneously acquiring images from the plurality of cameras are installed. The robot has a function of acquiring images and image processing functions from the camera, and transmits the current position information of the hanger transmitted from the distance measuring sensor 13 to each robot system. The position and attitude information of the body, To the system unit.

The robot system unit includes two or more robot bodies 22 and a controller 20, each of which is equipped with a carriage 21 so that the robot can perform a traveling operation in accordance with the conveyor synchronization.

Each of the robots 22 moves on the traveling axis 21 by synchronous operation of the conveyor 10, and a camera 24 is installed on the upper part.

The camera 24 is composed of a single or a stereo camera, and moves the robot to the position of the body feature point set for each vehicle type to acquire the feature point image.

That is, the camera 24 captures the vehicle body feature point pattern set in the body of the vehicle moving by the hanger 12, grasps the position of the body feature point pattern, corrects the vehicle body position caused by the vehicle body mounting error, 22) move together to perform the work.

Therefore, the camera 24 and the PC are referred to as a vision device 30 for measuring the three-dimensional position and posture change amount of the vehicle body through the measurement of the feature point position of the vehicle body, UBS work, RPP and deader painting work are performed using the three-dimensional position and posture change amount of the body.

A distance measurement sensor 13 provided on the continuous conveyor 10 and a reflector 14 provided on the hanger 12 are mounted on the hanger 12 to detect the position of the vehicle body being transported and the robot controller 20 And a control unit 31 for controlling the above structures so that the robot 22 measures the position of the vehicle body while moving through the communication with the visual device unit 30.

According to the figure, the reflector 14 installed on the hanger 12 and the distance measuring sensor 13 for measuring the distance between the reflector 14 and the hanger 12 are mounted on the hanger 12 on the continuous conveyor 10, A difference between a distance value between a plurality of vehicle body feature points calculated by measuring a three-dimensional position of a plurality of feature points with a sensing system and a distance value between vehicle body feature points calculated by a sensing system in a state where the conveyor is stopped is within a tolerance range An image of a plurality of feature points is instantaneously acquired.

An image processing technique capable of precisely calculating three-dimensional position information about a vehicle body reference axis using the obtained information, and a three-dimensional position and attitude change amount of an input body with respect to a reference body measured while the vehicle body is in motion So that the robot 22 can correct the sealing locus in response to the conveyor surging phenomenon in the work space and perform a precise sealing operation.

Therefore, the vehicle body UBS, RPP, and the like of the robot 22 with respect to the vehicle body being moved, without performing a temporary stop operation of the vehicle body as in the conventional method, on the continuous conveyor 10 by using the vehicle body position measurement system based on the continuous conveyor 10 according to the present invention, The deadner painting can be performed quickly and safely automatically.

The above description is only an example of the vehicle position measuring system based on the continuous conveyor 10 according to the present invention. It is to be understood that any person skilled in the art may make various changes The technical spirit of the present invention will be described.

As described above, according to the present invention, a single camera or a stereo camera is mounted on a plurality of articulated robot robots attached with a camera mounting stand and a traveling device, and then the robot is transferred to a conveyor, By measuring the three-dimensional positions of a plurality of feature points and the three-dimensional position and attitude change amounts of the body reference axis constituted by a plurality of body feature points by measuring the pattern by the pattern recognition and the stereo matching method for the feature points, There is an advantage that sealing or painting work can be performed finely. That is, there is an advantage that the vehicle body UBS and the painting operation by the robot on the moving body can be performed quickly and safely automatically.

Claims (4)

A visual device unit for measuring a three-dimensional position and an attitude change amount of the vehicle body through the measurement of the feature point position of the vehicle body; The traveling device is mounted on the continuous conveyor to perform the vehicle body UBS operation, the RPP and the Deadner painting operation on the continuous conveyor by using the three-dimensional position and posture change amount of the vehicle body measured by the visual device unit and the conveyor synchronization position tracking information, A plurality of robot system units capable of an encoder reader and a travel axis control; And And a controller for detecting the time of vehicle body entering and detecting the position of the vehicle body on the basis of the position of the body of the vehicle and the correction operation by the robot are sequentially communicated with the visual device unit and the robot system unit A central control unit for controlling the visual device unit and the robot system unit; Wherein the first and second sensors are configured to detect the position of the vehicle. The method according to claim 1, A distance measuring sensor for measuring the distance information from the reflected information to the vehicle body after emitting the laser by a laser reflector, which is fixedly installed at the upper end of the work space in a position and an attitude free from interference when the hanger is moved, And a reflector installed on the over hanging hanger to reflect the laser emitted from the distance measuring sensor. The apparatus according to claim 1 or 2, When a three-dimensional position of a plurality of feature points in a vehicle body that is mounted on a hanger on a continuous conveyor by a distance measuring sensor and a plurality of single or stereo cameras is measured, a distance value between a plurality of vehicle body feature points and a state in which the conveyor is stopped Wherein the controller is configured to instantaneously acquire an image for a plurality of feature points so that a difference in distance value between the measured body feature points can be within an allowable error range. A first step of reading conveyor encoder pulse information on a continuous conveyor; A second step of periodically performing a process of measuring distance information to a vehicle body by emitting a laser beam with a reflector installed on a hanger; A third step of correcting the conveyor synchronous position tracking range of the robot running axis within an allowable error range while compensating for a change amount of a current position of a hanger that may occur through conveyor surging using the information obtained from the first and second steps; And The position measurement operation of the vehicle body in the moving state while the vehicle body is seated on the hanger and the operation of the body UBS operation or the RPP and Deadner are performed without the operation of temporarily stopping the hanger on the continuous conveyor through the synchronous position tracking correction in the third step The method comprising the steps of: (a) detecting a position of the vehicle body;

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