KR100743144B1 - Tracking method and system for moving object of robot - Google Patents

Abstract

The present invention is a robot work line tracking method for the robot to follow the work being carried on the moving conveyor is carried out, the linear distance path planning based on the initial position of the workpiece and the initial position of the robot, the conveyor It is characterized by controlling and following the robot while compensating the transport distance of the workpiece according to the transport distance in real time to the path information of the path plan, and the controller of the robot predicts the time to enter within the robot working radius by looking at the moving speed of the workpiece. This makes it possible to use most of the robot's moving range as the following controllable area, and predicts the time when the work enters the robot working radius and compares it with the time it takes for the robot to move. Move the robot in advance so that the robot It had minimized the waiting time to waste it removes the time consuming, while the robot moves to the follow-up was good and also enables the tracking-based high-speed transport.

Robot, Work Line, Following, Work Area

Description

Tracking method and system for moving object of robot

1 is a working line tracking system configuration diagram of a robot for explaining the present invention.

Figure 2 is a detailed configuration of the work line tracking system of the robot for explaining the present invention.

3 is an explanatory diagram for explaining a work line following method of a robot for explaining the present invention.

<Description of the symbols for the main parts of the drawings>

1: robot 2: conveyor

3: workpiece 4: CCD camera

5: controller 10: workpiece position detector

20: Encoder 30: Servo Motor

100: work line following control unit 110: initial position detection unit

120: relative moving distance detector 130: moving speed detector

140: work location management unit 141: new work variable generation unit

142: location update unit of the entire work unit 143: current work position value management unit

150: situation determination management unit 160: robot operation control unit

161: the first path planning unit 162: real-time compensation unit moving distance

The present invention relates to a work line following control method of a robot, and more particularly, to a work line following method of a robot which can reduce a work line by following a position of a robot working on a conveyor belt.

Automated machines such as industrial robots combine multiple bodies and working tools to be independently movable and rotatable. In addition to the robot, the automation system introduced into the production line includes peripheral devices such as a transport truck on which the robot is mounted, an identification device for identifying whether a workpiece transported along the conveyor belt has reached a set position, and a robot controller for controlling the robot. .

A general method for controlling the robot's movement path so that a work machine mounted on the robot (hereinafter referred to as a 'robot') can follow the movement of the work and perform an appropriate task is to move the robot along a stored trajectory and detect it in real time. The path is corrected using the location data of the finished work.

That is, the tracking trajectory is corrected by using the position data of the workpiece detected in real time while driving the robot while referring to the table table of the storage device in which the robot tracks data to be tracked every unit time corresponding to the movement path of the set work. An operation processing method was applied. In addition, such a trajectory tracking control method requires a large-capacity calculator capable of processing large-scale operation data at high speed so that orbital correction can be performed in real time.

However, the automation system to which such a conventional method is applied for the work in which the work content applied to the workpiece from the robot is simple and the possible following trajectory range is not largely affected by the deviation from the set following trajectory is excessive. It is difficult to apply practically.

On the other hand, as a technology for improving the conventional problem as described above Patent Publication No. 1999-0002337 robot work line tracking control method is known, which is the target work for the workpiece transported by the feeder at a constant speed along one direction A robot equipped with a work machine capable of performing the operation, a robot controller for controlling the driving of the robot, and a first identification device for outputting a signal indicating that the workpiece being transported has arrived at a predetermined initial position to the robot controller; A work line tracking control method for a robot, comprising: storing data information including a conveying direction and a conveying speed of the workpiece in the robot controller; Calculating a linear distance between the initial position and the work machine position; Calculating a time taken for the work machine to move the straight line at a predetermined speed; Calculating a moving distance of the workpiece on the conveyor during the required time; Selecting a first position corresponding to the movement distance and a second position located a predetermined distance forward from the first position along the traveling direction of the workpiece from the initial position on the coordinate system of the conveyor; Converting a second position into coordinate data to be linearly moved along the traveling direction of the work machine and the conveyor; If it is determined that the workpiece has reached the initial position by a signal output from the first identification device, reaching the work machine to the first position for the required time; And performing a desired operation with the work machine in a transport section corresponding to a transport distance corresponding to the second position from the first position; preferably, corresponding to the second position from the first position. Determining whether the work is within the workable area of the work machine when the work machine reaches the first position in the step of performing the work in the transport section corresponding to the transport distance; and the determining step Moving the work machine to a next set position after the predetermined work is performed if the work piece is within the workable area, and if the work is not within the workable area in the determining step, transferring the work machine every unit time. A repeating step of repeating the determining step while determining whether the second position has been reached while transferring along the machine; Moving the operating mechanism in the repeating step to the next position is set Once you have the working machine reaches the second position; It includes.

However, the work line tracking control method of the robot according to the prior art as described above is applied when the workpiece is being transported at a constant speed and cannot be tracked at an irregular transport speed rather than a constant speed.

In addition, since the robot's transport speed and the robot's transport speed are equal to each other after the robot is close to the workpiece, the robot can grab the workpiece or perform a desired task.

In this conventional method, the work area is smaller than the actual robot moving range by selecting the work area as a rectangle.

In addition, efficiency is lowered because the robot is operated by determining whether the object is present in the work area, not predicting when an object enters the work area. In addition, it is time-consuming and inefficient because the work must be performed at the same speed only when the workpiece is positioned.

In addition, since the following state is defined as the following distance, the distance is relative, so the concept may become ambiguous according to the conveyor speed, and when the speed of the conveyor changes or stops when the object is picked up by following the workpiece. There was a problem that it is impossible to apply.

The present invention is to provide a method for following the work line of the robot to enable the work line tracking even if the feed rate of the workpiece is not constant in view of the above conventional problems.

In addition, the present invention is to enable the operation control of the robot effectively by maximizing the work area by starting the tracking control outside the work area.

In addition, the present invention is to follow the robot to move automatically the same as the conveying speed of the workpiece after arriving at the workpiece to avoid the need for follow-up control to adjust the feed rate separately.

In addition, the present invention is to be able to follow the work line with only a small capacity processor without using expensive large-capacity calculator by processing the work line transfer control of the robot in a simple manner.

The present invention is to improve the working efficiency of the robot on the user side compared to the existing conveyor tracking method, and to enable developers to perform complex work on the moving conveyor with a simple modification in the existing robot motion method. .

The present invention plans the trajectory for following the feeder to a straight line with the least computation time and simply adds the trajectory generated by the position change of the feeder to the trajectory in the environment where the speed changes without using a large-capacity calculator. Made it possible.

In addition, in the following tracking control, the tracking control is possible only in a specific area within the robot working area. However, in the present invention, the controller of the robot can track the most moving range of the robot by looking at the moving speed of the work and predicting the time to enter the robot working radius. It can be used as an area.

In addition, in the conventional method, the robot starts following the target on an object already in the work area. However, in the present invention, the work is predicted when the work enters the robot working radius and compared with the time taken for the robot to move. By moving the robot in advance so that the robot can reach its position when entering the work area, it minimizes the time the robot spends waiting for the work, which eliminates the time spent by the robot moving to the follower line and Following was also possible.

The workline following method of a robot according to the present invention is a workline following method of a robot, in which a robot follows a work being carried on a conveyer conveyed on a conveying conveyor, the initial position of the work and the initial position of the robot. Based on the linear distance route plan, and by controlling the robot while compensating for the route information of the route plan in real time to compensate the transfer distance of the workpiece according to the conveying distance of the conveyor.

The entry time of the workpiece is determined by comparing the time from the initial position to the work area boundary of the robot and the time from the initial position of the robot to the initial position of the workpiece. If it is less than or equal to time, it is characterized in that it follows the starting point of following the robot.

In addition, when the workpiece is in the work area of the robot, the workpiece departure time plus the time from the current position of the work to move out of the boundary of the work area of the robot and the time the robot reaches the work, and the work Comparing the time to reach the current position of the workpiece from the initial position of the robot, if the departure time of the workpiece is less than or equal to the arrival time of the robot, the robot will give up following and control following the other workpiece do.

In addition, when a position of a new workpiece is detected, a management variable is assigned to the workpiece, and each position is updated to a new initial position different from the conveyor transfer distance in the previous position information for the entire workpiece to which the management variable is assigned. It manages, and gives priority to the work target from the work with the shortest time that the work leaves the work area of the robot, characterized in that the tracking control according to the priority.

According to the present invention, there is provided a work line tracking control method for a robot, comprising: a first step of detecting an initial position of a workpiece and an initial position of the robot; A second step of planning a path in the axial direction and the transfer direction (initial position = 0) for the linear distance movement from the initial position of the robot to the initial position of the workpiece, and calculating the movement time of the linear distance path; A third step of calculating a transfer time from an initial position of the workpiece to a starting position of a work region entering the work region of the robot; A fourth step of starting path tracking of the robot when the transfer time of the work is equal to or less than the transfer time of the robot by comparing the transfer time of the work of the second step with the transfer time of the work of the third step; A fifth step of modifying the path by adding the distance per unit time at which the work is to be transferred to the transport distance value of the workpiece transport direction of the path of the robot while starting the robot by the linear distance travel path planning of the robot; When the axial transfer to the workpiece of the path plan of the robot is completed, it is characterized in that it is made to perform a sixth step of completing the work line following the movement while maintaining only the movement in the transfer direction.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic configuration diagram for explaining a work line following method of a robot according to the present invention.

As shown therein, the robot 1 whose operation is controlled through the servo motor 30 by the control of the robot controller 5 is picked up on the conveyor 2 and picked up the workpiece 3 to be transported or other. In a robot system configured to perform work, a workpiece position detector (10) for detecting the position coordinates of the workpiece (3) in the CCD (4) for photographing the workpiece (3) and an image obtained from the CCD (4). ) Is installed, and an encoder 20 for detecting the conveying speed of the conveyor 3 is installed.

According to the present invention, the work line tracking control unit 100 is mounted in the robot controller 5 as a program, and the workpiece position information of the workpiece position detector 10 and the conveyor conveyance speed and the conveying distance information of the encoder 20. According to the control is made to control the work line tracking of the robot.

2 is a detailed configuration diagram of a work line following control unit of the robot according to the present invention.

As shown in this, the initial position detection unit 110 for detecting the initial position information of the workpiece when the new object is found from the workpiece position detector 10,

A relative movement distance detector 120 which receives movement information of the conveyor from the encoder 20 and detects a movement distance of the workpiece;

A moving speed detector 130 for detecting a moving speed of the workpiece according to the moving speed of the conveyor from the encoder 20;

Receives initial position information of the workpiece of the initial position detection unit 110 each time a new object is found, generates a new workpiece variable, receives movement distance information from the relative movement distance detection unit 120, and updates the position information of the entire workpiece. And, the workpiece position management unit 140 for managing the position value of the current workpiece,

Receives the movement speed information of the workpiece from the movement speed detector 130 and receives the current workpiece position information from the workpiece position manager 140 to detect the linear distance movement time from the initial position of the robot to the initial position of the workpiece. And detecting the time until the current work enters the boundary of the robot's work area or the time until the current work leaves the work area of the robot and determines whether to start following the work line of the robot. Determination unit 150,

Calculate the linear distance from the current position of the robot to the initial position of the current work to plan the movement path of the robot for the linear distance, the current job input from the relative movement distance detection unit 120 to the information of the route plan Comprising a real-time compensation of the moving distance of the water to the robot motion control unit 160 for controlling the operation for following the work line.

The workpiece position management unit 140 receives the initial position information of the corresponding workpiece every time a new object is found from the initial position detection unit 110 and generates a new workpiece variable to generate a new workpiece variable for managing a plurality of workpiece variables. When a new workpiece variable is generated by the unit 141 and the new workpiece variable generator 141, the real-time movement distance input from the relative movement distance detector 120 is reflected in the workpiece position information of each variable. The overall workpiece position updating unit 142 for updating the current position information of all the workpieces, and the position value of the current workpiece that the current robot is to control the work line following from the overall workpiece position updating unit 142. It is composed of the current work position value management unit 143 to manage.

The robot motion controller 160 calculates a linear distance based on the initial position of the current work and the current position of the robot, that is, the initial position of the robot, and establishes a path plan for the linear distance. And an object moving distance for real-time compensating the moving distance of the workpiece detected by the relative moving distance detecting unit 120 to the path planning information established by the primary path planning unit 161 and outputting an operation control command of the robot to the servomotor. It consists of a real-time compensation unit 162.

According to the workline tracking method of the robot according to the present invention configured as described above, as shown in FIG. 1, the robot 1 is a workpiece when a plurality of workpieces 3 are placed and transported on the conveyor 2. To pick up (3) or perform other tasks, the robot 1 controls the following approach to the workpiece. This captures an image of the workpiece 3 through the CCD camera 4 and detects the position of the workpiece 3 in three-dimensional coordinates by the workpiece position detector 10. At this time, the encoder 20 detects the conveying speed of the conveyor 2 and inputs it to the work line following controller 100.

The robot controller 5 detects and updates the initial position of the robot, that is, the current position information of the robot and the information about the boundary of the work area of the robot in real time, and the position information and the work area information of the robot are the work line following controller 100. It is input to) and used for work line following control.

The robot controller 5 controls the servo motor 30 based on the route plan information compensated for the movement distance output from the robot work line follower control unit 100 to control the robot 1 to move the work line following and You will control what you want to do.

The work line following control unit 100 of the robot according to the present invention, as a main feature, establishes a straight path plan based on the initial position information of the workpiece and the initial position information of the robot, and works on the robot movement information according to the straight path plan. It compensates the moving distance of water in real time and when the axial movement to the work is completed, it is determined that the work line following is completed and the work is performed. At this time, when the axial movement is completed, since the horizontal movement speed of the robot moves in accordance with the movement speed of the work, the work on the work can be performed without impact.

3 is an explanatory diagram illustrating a coordinate system for explaining the present invention, wherein an axial coordinate from the initial position of the robot to the initial position of the workpiece is called + Y coordinate, and the initial position of the workpiece is Y (t). If the movement direction, that is, the horizontal direction is + X, the robot follows the workpiece while the robot simultaneously moves in the Y direction, the axial direction and the X direction, the transfer direction. In the present invention, the Y direction is described as the axial direction and the X direction as the horizontal direction or the moving direction.

First, the initial position detection unit 10 detects the position of the workpiece 3 that is lifted and moved on the conveyor 2, and inputs it to the workpiece position management unit 140, each time a new workpiece is found. Then, the relative movement distance detection unit 120 receives the conveyor transfer information from the encoder 20 detects and inputs as the movement distance information. Accordingly, the workpiece position management unit 140 manages the new workpiece variable generation unit 141 as a new variable every time a new workpiece is found, and the entire workpiece position updating unit 142 compensates the relative moving distance. The location information of each work is updated, and the work that leaves the robot's work area is requested to delete the variable and is no longer managed. Then, the current workpiece position value management unit 143 selects the workpiece having the highest priority for the robot 1 to work as the current workpiece and performs position management. This is the smallest time to leave the work area within the work area among the plurality of work pieces that are determined and determined by the situation determination management unit 150, but the work having the time that the robot can work has the highest priority. Select the current work to control the work line following.

The situation determination management unit 150 receives the current position information of the work, that is, the initial position of the work, and moves the robot's work time (constant value) to the moving time from the current position of the work to the distance from the robot's work area. Add to detect the workpiece travel time, detect the time that the robot can reach the work line by following the workline, compare the two times, and move out of the work area or run out of work area before the robot follows the reach. In this case, it is excluded from the work object and the following control is controlled for other work, and when the robot reaches the work and reaches the work time, it starts to follow the work.

On the other hand, when the work enters the robot work area, the time when the robot follows the work and the time when the work enters the robot work area is compared. Start following the work where possible.

As described above, when the tracking start command is generated by determining the starting point of the robot's work line tracking, the robot motion controller 160 controls the robot to start tracking.

The primary path planning unit 161 establishes a path plan for the robot to move in a straight line by the initial position of the workpiece and the initial position of the robot. In general, the route plan is controlled by the initial acceleration-> constant velocity-> deceleration operation of the robot to establish a route plan to the moving position and control the robot based on the route plan. In the present invention, the work is moving on the conveyor. For example, the robot can follow the moving workpiece by compensating the moving distance of the workpiece in real time and adding the distance in the direction of the route plan.

As described above, the present invention provides a method for control and procedure for efficiently performing a task of following a robot on a moving conveyor, 1) setting a tracking work area to the entire robot moving range, and 2) real-time position of the work. Predict the time when the work enters the work area, compare the time it takes with the time the robot operates, and 3) allow the robot to be located on the work at the time the work arrives in the work area. Determines the start time of operation. 4) If there is already a work in the work area, judge whether the work is out of the work area while the robot is moving, and if it can be followed, do this. If not, give it up and select the next work. 5) The robot plans a path with a straight line that reaches the object based on the starting point, and then compensates for the distance that the object has moved to eliminate following errors. 6) As soon as the robot reaches the position of the following object, the velocity component on the straight line path becomes zero and only the moving compensation speed remains, so the robot has the same speed as the workpiece at this moment. This eliminates the need for time consuming to have a tracking speed.

According to the present invention, in following the work line of the robot, the robot can move according to the anticipation of the time required for the work to enter the work area of the robot in advance so that the work can be performed immediately following the completion of the work. The maximum speed and space utilization can be maximized, and the following speed can be minimized since it has the same speed as the object upon arrival of the object position.

In addition, the present invention is easier to define than the distance in the conveyor difficult to define the absolute coordinates by defining the object tracking state by the time, and the next object when the object leaves the working area during the operation time in anticipation of the operation speed of the robot Automatic selection results in improved work line stoppage.

In addition, since the moving distance of the conveyor is directly added to the reference value according to the basic route plan as a simplified real-time tracking position compensation, there is an effect that the computation process can be performed with almost no difference in the amount of computation compared to the general motion.

Claims (7)

In the method of following the robot's work line for the robot to follow the work being carried on the conveying conveyer conveyed work, Based on the initial position of the workpiece and the initial position of the robot to establish a straight distance route plan, and control and follow the robot while compensating for the route information of the route plan in real time to compensate the transport distance of the workpiece according to the conveying distance of the conveyor, The entry time of the workpiece is compared with the arrival time of the robot by comparing the time from the initial position to the work area boundary of the robot and the time from the initial position of the robot to the initial position of the workpiece. If the same or less than the robot's work line tracking method characterized in that the starting point of the tracking of the robot. delete The method of claim 1, When the work is in the robot's work area, the work departure time plus the time from the current position of the work to move out of the robot's work area boundary, and the time that the robot reaches and works on the work, and the robot Comparing the time to reach the current position of the workpiece from the initial position of the if the departure time of the workpiece is less than or equal to the arrival time of the robot characterized in that abandon the tracking of the robot and follow the control of other workpieces How to follow the work line of a robot. According to claim 1 or claim 3, when the position of the new workpiece is detected, assigning a management variable to the workpiece, and for each of the workpieces to which the management variable has been assigned, each position to the conveyor position transfer distance It updates and manages to a new initial position according to, characterized in that the following control is controlled according to the priority by assigning priority to the work target from the shortest time the work leaves the work area of the robot How to follow the work line of a robot. A first step of detecting an initial position of the workpiece and an initial position of the robot; A second step of establishing a route plan in an axial direction and a transfer direction for the linear distance movement from the initial position of the robot to the initial position of the workpiece, and calculating the movement time of the linear distance path; A third step of calculating a transfer time from an initial position of the workpiece to a starting position of a work region entering the work region of the robot; A fourth step of starting path tracking of the robot when the transfer time of the work is equal to or less than the transfer time of the robot by comparing the transfer time of the work of the second step with the transfer time of the work of the third step; A fifth step of modifying the path by adding the distance per unit time at which the work is to be transferred to the transport distance value of the workpiece transport direction of the path of the robot while starting the robot by the linear distance travel path planning of the robot; When the axial transfer to the workpiece of the path planning of the robot is completed, the work line following method of the robot, characterized in that to perform the sixth step of completing the work line following the maintenance of the movement direction only. In the robot's work line tracking system for the robot controller to control the movement of the robot through the servo motor to follow the workpiece being transported on the conveyor, A workpiece position detector 10 for detecting position information of the workpiece, and an encoder 20 for detecting a transfer speed and a movement distance of the transfer conveyor, An initial position detector 110 for detecting initial position information of the workpiece when a new object is found from the workpiece position detector 10; A relative movement distance detector 120 which receives movement information of the conveyor from the encoder 20 and detects a movement distance of the workpiece; A moving speed detector 130 for detecting a moving speed of the workpiece according to the moving speed of the conveyor from the encoder 20; Receives initial position information of the workpiece of the initial position detection unit 110 each time a new object is found, generates a new workpiece variable, receives movement distance information from the relative movement distance detection unit 120, and updates the position information of the entire workpiece. And, the workpiece position management unit 140 for managing the position value of the current workpiece, Receives the movement speed information of the workpiece from the movement speed detector 130 and receives the current workpiece position information from the workpiece position manager 140 to detect the linear distance movement time from the initial position of the robot to the initial position of the workpiece. And detecting the time until the current work enters the boundary of the robot's work area or the time until the current work leaves the work area of the robot and determines whether to start following the work line of the robot. Determination unit 150, Calculate the linear distance from the current position of the robot to the initial position of the current work to plan the movement path of the robot for the linear distance, the current job input from the relative movement distance detection unit 120 to the information of the route plan Work line tracking system of a robot, characterized in that the robot motion control unit 160 for controlling the movement for tracking the work line of the robot by compensating the movement distance of the water in real time. According to claim 6, The workpiece position management unit 140, New workpiece variable generation unit 141 for managing a plurality of workpieces by generating a new workpiece variable by receiving initial position information of the corresponding workpiece every time a new object is found from the initial position detection unit 110, When a new work variable is generated by the new work variable generator 141, the current position information of the entire work is reflected by reflecting the real-time moving distance input from the relative moving distance detector 120 to the work position information of each variable. And the overall workpiece position update unit 142 for updating the, Work of the robot, characterized in that the current workpiece position value management unit 143 for managing the position value of the current workpiece that the current robot is to control the work line following from the overall workpiece position update unit 142 Line following system.

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