JP2024000289A - Control method and control device of robot system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control method and a control device of a robot system that can perform conveyance of an object with high accuracy.

SOLUTION: A control method of a robot system, which holds an object being conveyed by a conveying device and conveys the held object to a target position, includes: a conveyance starting position predicting step of determining a predicted position at which conveyance of the object to the target position is started; a conveyance route generating step of generating a conveyance route for the object from the predicted position to the target position; a conveyance starting step of starting conveyance of the held object to the target position; and a correcting step of correcting the conveyance route, using a difference between a starting position at which the conveyance is started and the predicted position.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a control method and a control device for a robot system.

For example, in the robot tracking control method described in Patent Document 1, a camera placed directly above the conveyor continuously images a workpiece conveyed by a conveyor, and based on the imaged results, the position and conveyance speed of the workpiece are determined. and a step of estimating the target position of the tracking operation by repeatedly calculating from the conveyance speed of the workpiece and the operation time of the robot.

Japanese Patent Application Publication No. 10-105217

However, in Patent Document 1, even if the robot is able to start tracking a workpiece being transported by a conveyor, it is not always possible for the robot to pick up the workpiece and transport the picked-up workpiece to a target position. do not have. In particular, if the transport route after being picked up is predetermined, if the actual position at which transport starts after being picked up deviates from the starting point of the transport route, that deviation will directly lead to a deviation from the target position. There's a problem.

A method for controlling a robot system according to the present invention is a method for controlling a robot system that holds an object to be transported by a transport device and transports the held object to a target position, the method comprising:
a transport start position predicting step of determining a predicted position to start transporting the object to the target position;
a transport route generation step of generating a transport route for the object from the predicted position to the target position;
a transport start step of starting transport of the held object to the target position;
The method includes a correction step of correcting the transport route using a difference between the start position at which the transport is started and the predicted position.

The control device of the present invention is a control device for a robot system that holds a target object transported by a transport device and transports the held target object to a target position, comprising:
a transport start position predicting step of determining a predicted position to start transporting the object to the target position;
a transport route generation step of generating a transport route for the object from the predicted position to the target position;
a transport start step of starting transport of the held object to the target position;
A correction step of correcting the transport route using the difference between the start position at which the transport was started and the predicted position is executed.

1 is an overall configuration diagram of a robot system according to a preferred embodiment. 3 is a flowchart showing a method of controlling the robot system. FIG. 3 is a front view showing a state where the transport device has started transporting the workpiece. FIG. 3 is a front view showing how the imaging section images the workpiece. FIG. 3 is a top view showing a generated transport route. FIG. 3 is a front view showing how the robot holds a workpiece. FIG. 3 is a top view showing how a positional shift of a target position occurs. FIG. 7 is a top view showing a correction conveyance path. FIG. 7 is a top view showing a conveyance path corrected by a first correction method. FIG. 7 is a top view showing a conveyance path corrected by a second correction method. FIG. 7 is a top view showing a conveyance path corrected by a third correction method. FIG. 2 is a diagram illustrating an example of a graphic interface.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A robot system control method and control device according to the present invention will be described in detail below based on embodiments shown in the accompanying drawings.

FIG. 1 is an overall configuration diagram of a robot system according to a preferred embodiment. FIG. 2 is a flowchart showing a method of controlling the robot system. FIG. 3 is a front view showing a state in which the transport device has started transporting the workpiece. FIG. 4 is a front view showing how the imaging section images the workpiece. FIG. 5 is a top view showing the generated transport route. FIG. 6 is a front view showing how the robot holds a workpiece. FIG. 7 is a top view showing how the target position shifts. FIG. 8 is a top view showing the correction conveyance path. FIG. 9 is a top view showing the conveyance path corrected by the first correction method. FIG. 10 is a top view showing the conveyance path corrected by the second correction method. FIG. 11 is a top view showing the conveyance path corrected by the third correction method. FIG. 12 is a diagram showing an example of a graphic interface.

The robot system 1 shown in FIG. 1 includes a robot 2, an imaging section 3, a control device 4, a transport device 6, and a display device 8. Note that the robot 2, the imaging unit 3, and the transport device 6 have been calibrated, and their relative positional relationships are known.

In the robot system 1, a transport device 6 transports a workpiece W as an object along a transport direction A, and a control device 4 transports the workpiece W as an object based on an image G acquired by the imaging unit 3 and the transport speed of the workpiece W. The robot 2 holds the work W while running parallel to (tracking) the work W being transported based on the detected transport situation, and transports the held work W to a target position. In this embodiment, as shown in FIG. 1, the work W is transported while being housed in a box-shaped case C. However, the present invention is not limited to this, and for example, the workpiece W may be transported in an exposed state.

As shown in FIG. 1, the robot 2 is a six-axis vertical articulated robot having six drive axes, and includes a base body 21, a robot arm 22 rotatably connected to the base body 21, and a robot arm 22 that is rotatably connected to the base body 21. It has an end effector 23 attached to the tip. The robot arm 22 is a robotic arm in which a plurality of arms 221, 222, 223, 224, 225, and 226 are rotatably connected, and includes six joints J1 to J6. Among these, joints J2, J3, and J5 are bending joints, and joints J1, J4, and J6 are torsion joints. The end effector 23 is appropriately selected depending on the intended work. In the illustrated configuration, the end effector 23 is configured to suction and hold the workpiece W using an air chuck.

Furthermore, a motor M and an encoder E for detecting the amount of rotation of the motor M are installed at each of the joints J1, J2, J3, J4, J5, and J6. During operation of the robot system 1, the control device 4 executes servo control (feedback control) for each joint J1 to J6 to match the rotation angle of the joints J1 to J6 indicated by the output of the encoder E with a control target.

The conveyance device 6 is a belt conveyor, and includes a belt 62, a conveyance roller 63 that sends the belt 62, a motor 61 that drives the conveyance roller 63, and an encoder that outputs a signal according to the amount of rotation of the belt 62 to the control device 4. 64. During operation of the robot system 1, the control device 4 executes servo control (feedback control) to make the transport speed of the workpiece W indicated by the output of the encoder 64 coincide with a target transport speed that is a control target.

The imaging unit 3 is a camera that images the workpiece W from above the transport device 6 and outputs the captured image to the control device 4 . The imaging area of the imaging unit 3 is located upstream of the work area of the robot 2 in the transport direction A. The position of each pixel in the image output from the imaging unit 3 is associated with the position on the transport path by the control device 4. Therefore, when the workpiece W exists within the field of view of the imaging section 3, the time at which the image was captured (hereinafter also referred to as "image acquisition time Ti") is determined based on the position of the workpiece W in the image of the imaging section 3. ) can be specified.

The control device 4 controls the driving of the robot 2, the imaging section 3, and the transport device 6, respectively. The control device 4 is composed of, for example, a computer, and includes a processor (CPU) that processes information, a memory that is communicably connected to the processor, and an external interface that connects to external devices. The memory stores various programs executable by the processor, and the processor can read and execute the various programs stored in the memory. Note that some or all of the components of the control device 4 may be placed inside the housing of the robot 2. Further, the control device 4 may be configured by a plurality of processors.

The configuration of the robot system 1 has been briefly described above. Such a robot system 1 operates as follows. First, the control device 4 operates the transport device 6 and controls the drive of the control device 4 so that the transport speed of the workpiece W detected based on the output of the encoder 64 becomes the target transport speed. In this state, the work W is supplied to the transport device 6, and the transport of the work W by the transport device 6 is started. Next, the control device 4 uses the imaging unit 3 to image the workpiece W passing through the imaging area, and obtains an image G in which the workpiece W is captured. Next, the control device 4 detects the coordinates of the workpiece W at the time when the image G is acquired from the image G. Next, the control device 4 calculates the position of the work W at each future time from the coordinates of the work W at the time when the image G was acquired and the transport speed of the work W, and controls the robot 2 based on the calculated position. Calculate the signal. Then, the control device 4 drives the robot 2 using the calculated control signal, and causes the robot 2 to perform a predetermined work on the workpiece W being transported.

Next, the predetermined work will be explained. In this embodiment, the predetermined work includes a holding step of holding (picking) the workpiece W transported by the transporting device 6, and a transporting step of transporting the held workpiece W to the target position Pe. The control method of the robot system 1 when performing such work includes a workpiece transport step S1 in which the workpiece W is transported by the transport device 6, and a transport start step in which a predicted position Ps for starting transport of the workpiece W to the target position Pe is determined. A position prediction step S2, a transport route generation step S3 that generates a transport route E1 for the workpiece W from the predicted position Ps to the target position Pe, a workpiece holding step S4 that holds the workpiece W, and a target position Pe of the held workpiece W. The transport is performed using the difference between the start position Ps' at which transport of the work W is actually started in the transport start step S5 and the predicted position Ps predicted in the transport start position prediction step S2. A correction step S6 for correcting the route E1 is included. Hereinafter, each of these steps S1 to S6 will be explained in detail based on the flowchart shown in FIG.

[Workpiece conveyance step S1]
First, the control device 4 starts driving the conveyance device 6, and makes the conveyance speed Vs of the workpiece W indicated by the output of the encoder 64 match the target conveyance speed. Thereby, as shown in FIG. 3, the workpiece W placed on the transport device 6 is transported at the target transport speed. Note that the method for supplying the work W to the transport device 6 is not particularly limited, and can be performed using, for example, a robot, a parts feeder, or the like. Alternatively, it may be supplied manually by a worker.

[Transportation start position prediction step S2]
When the transport device 6 starts transporting the workpiece W, the control device 4 uses the imaging unit 3 to image the workpiece W passing through the imaging area, and obtains an image G in which the workpiece W is captured. Next, the control device 4 determines the position (coordinates) of the workpiece W at the time when the image G was acquired, that is, at the image acquisition time Ti, based on the acquired image G. Next, as shown in FIG. 4, the control device 4 performs a transport start step based on the image acquisition time Ti, the position of the work W at the image acquisition time Ti, the transport speed Vs, the time required for the work holding step S4, etc. A predicted position Ps, which is the position to start S5, is determined. Note that the predicted position Ps refers to the position of the robot 2, and more specifically refers to the position of a TCP (tool center point) set at the tip of the robot arm 22, for example.

However, the method for determining the predicted position Ps is not particularly limited. For example, in the above-described method, a preset target transport speed is used as the transport speed Vs of the workpiece W, but the present invention is not limited thereto. For example, the control device 4 continuously images the workpiece W at a predetermined frame rate using the imaging unit 3 while the workpiece W passes through the imaging area, and acquires a plurality of images in which the workpiece W is captured. Next, the control device 4 determines the position of the workpiece W in each image, and determines the transport speed Vs of the workpiece W based on the shift amount of the workpiece W between images (the distance traveled by the workpiece W) and the frame rate. You can.

[Transport route generation step S3]
In the transport route generation step S3, the control device 4 generates a transport route E1 for the workpiece W from the predicted position Ps obtained in the transport start position prediction step S2 to the target position Pe, as shown in FIG. An operation start time Ts for starting step S5 is set. The transport route E1 can be appropriately set based on the state of the workpiece W, the range of motion of the robot 2, the surrounding environment of the robot 2 (presence or absence of obstacles, etc.), and the like. Further, the transport route E1 is a parameter that defines the moving direction and moving distance of the robot 2.

[Work holding step S4]
In the workpiece holding step S4, as shown in FIG. 6, the control device 4 controls the drive of the robot 2 to hold the workpiece W transported on the transporting device 6 by the end effector 23. Specifically, the steps include a step of moving the end effector 23 parallel to the workpiece W and positioning it directly above the workpiece W, a step of lowering the end effector 23 to come into contact with the workpiece W, and a step of sucking the workpiece W by the end effector 23. The workpiece W is held by performing the holding step. Note that, as described above, since the workpiece W is housed in the case C, the end effector 23 continues to run parallel to the workpiece W even after the workpiece W is held. If the parallel running is stopped, the workpiece W will collide with the case C, which may cause damage to the workpiece W or work errors.

[Transportation start step S5]
In the transport start step S5, the control device 4 first determines whether the operation start time Ts has arrived, and if the operation start time Ts has arrived, the control device 4 moves the workpiece along the transport route E1 generated in the transport route generation step S3. Drive control of the robot 2 is started so that W moves. However, due to various causes such as variations in the time required for calculation processing by the control device 4, variations in the time required for communication between various parts, and variations in the conveyance speed Vs with respect to the target conveyance speed, as shown in FIG. There is a possibility that the actual start position Ps' may deviate from the predicted position Ps predicted in the transport start position prediction step S2. In particular, as in the present embodiment, in order to avoid contact between the case C and the workpiece W, the next operation, that is, transporting the workpiece W to the target position Pe, is performed from the state in which the robot 2 runs parallel to the workpiece W. In such a case, the starting position Ps' is likely to deviate from the predicted position Ps.

If the starting position Ps' deviates from the predicted position Ps in this way, the deviation will continue to occur at the target position Pe. In other words, the actual transport position Pe' deviates from the target position Pe by the same amount as the deviation of the start position Ps' from the predicted position Ps. Therefore, accurate conveyance work cannot be performed. Therefore, the control device 4 performs a correction step S6 in which the transport path E1 is corrected based on the difference ΔPs (displacement) between the predicted position Ps and the start position Ps' so that the transport position Pe' matches the target position Pe. .

[Correction step S6]
In the correction step S6, the control device 4 first determines the start position Ps' at which the conveyance start step S5 is started. Although the method for determining the starting position Ps' is not particularly limited, in this embodiment, the starting position Ps' is determined based on the output from the encoder E of each joint J1, J2, J3, J4, J5, and J6 of the robot 2. According to such a method, the starting position Ps' can be found easily and with high accuracy. Next, as shown in FIG. 8, the control device 4 generates a correction transport path E2 for moving the workpiece W from the starting position Ps' to the predicted position Ps. Next, the control device 4 uses the correction transport path E2 to correct the transport path E1 in one of the following three methods. In this way, by correcting the conveyance path E1 using the correction conveyance path E2, the difference ΔPs between the predicted position Ps and the starting position Ps' can be easily canceled.

-First correction method-
In the first correction method, as shown in FIG. 9, the control device 4 combines the conveyance path E1 and the correction conveyance path E2, that is, adds the conveyance path E1 and the correction conveyance path E2, and creates a new A transport route E3 is generated. At this time, the robot 2 has already started moving based on the transport path E1. Therefore, the transport route E3 is generated little by little while the robot 2 transports the work W, and the robot 2 updates the transport route E3 and transports the work W every time it receives the generated transport route E3. Thereby, the difference ΔPs between the predicted position Ps and the starting position Ps' is canceled, and the workpiece W can be transported to the target position Pe.

According to such a first correction method, the total moving distance of the workpiece W can be shortened compared to the second and third correction methods described later, and the time required for transportation (takt time) can be shortened. .

-Second correction method-
In the second correction method, as shown in FIG. 10, the control device 4 transports the workpiece W on the correction transport path E2 before transporting the workpiece W on the transport path E1. That is, the control device 4 performs a correction that adds the corrective transport route E2 before the transport route E1, and generates a new transport route E3. Thereby, the difference ΔPs between the predicted position Ps and the starting position Ps' is canceled, and the workpiece W can be transported to the target position Pe.

According to such a second correction method, the approach direction to the target position Pe does not change, and even when there are restrictions on the approach direction to the target position Pe, such as when the target position Pe is surrounded by walls on three sides, an appropriate Transport can be carried out. Further, it becomes easier for the user to predict the route, and it is easier for the user to avoid problems such as coming into contact with obstacles during transportation, for example.

-Third correction method-
In the third correction method, as shown in FIG. 11, the control device 4 transports the workpiece W along the transport path E1, and then transports the work W along the correction transport path E2. That is, the control device 4 performs a correction that adds the corrective transport route E2 after the transport route E1, and generates a new transport route E3. Thereby, the difference ΔPs between the predicted position Ps and the starting position Ps' is canceled, and the workpiece W can be transported to the target position Pe.

According to such a third correction method, the direction of movement from the start position Ps' is the same as the conveyance path E1, and even when there are restrictions on the direction of movement, such as when surrounded by walls on three sides, an appropriate Transport can be carried out. In addition, it becomes easier to predict the route, and it is easier to avoid problems such as coming into contact with obstacles during transportation, for example.

After correcting the transport path E1 using one of the three correction methods described above, the control device 4 controls the drive of the robot 2 so that the workpiece W is transported along the corrected transport path E3. do. According to such a control method, even if a deviation occurs between the start position Ps' and the predicted position Ps, the deviation is canceled during transport of the workpiece W, and the workpiece W can be transported to the target position Pe. Therefore, the workpiece W can be transported with excellent accuracy.

Returning to FIG. 2, in such a correction step S6, the control device 4 first performs correction based on the output from the encoder E of each joint J1, J2, J3, J4, J5, and J6 of the robot 2 in step S61. to find the starting position Ps'. Next, in step S62, the control device 4 calculates the difference ΔPs between the predicted position Ps and the starting position Ps'. Next, in step S63, the control device 4 determines whether to correct the transport path E1 based on the result of comparing the difference ΔPs with a preset tolerance range. Preset tolerance ranges include tolerance ranges set by the user, tolerance ranges stored in the robot's memory from the time of shipment, optimal tolerance ranges stored by the robot in its memory through machine learning, etc. It will be done.

In step S63, if it is determined that the transport path E1 is not to be corrected, the drive of the robot 2 is controlled so that the workpiece W moves along the transport path E1 without correcting the transport path E1. For example, if the difference ΔPs is within the allowable range, the control device 4 drives the robot 2 so that the workpiece W moves along the transport path E1 without correcting the transport path E1 in step S64. control. In this way, by not correcting the transport path E1 when the difference ΔPs is within the allowable range, the workpiece W can be quickly transported to the target position Pe, and the time required for transport (takt time) is shortened. be able to.

On the other hand, when it is determined in step S63 that the conveyance path E1 is to be corrected, the control device 4, in step S65, sets the correction conveyance path E2 for conveying the workpiece W from the starting position Ps' to the predicted position Ps. generate. For example, if the difference ΔPs is outside the allowable range, the control device 4 generates a correction transport path E2 for transporting the workpiece W from the starting position Ps' to the predicted position Ps in step S65. Next, in step S66, the control device 4 selects one of the above-described first, second, and third correction methods as a method for correcting the transport path E1. The selection method is not particularly limited, but in this embodiment, the user is required to make a selection in advance.

For example, in this embodiment, a graphic interface 80 as shown in FIG. 12 is displayed on the display device 8, and input from the user can be received via the graphic interface 80. The graphic interface 80 displays a column for selecting one of the first correction method, second correction method, and third correction method as the correction method. Therefore, the user can select one of the first correction method, second correction method, and third correction method in consideration of the work content, work environment, etc. However, the setting is not limited to this, and the control device 4 may automatically set the setting based on the work content, work environment, etc. In this way, by having a configuration in which the correction method can be selected, the transport path E1 can be corrected using a method suitable for the situation, so that the transport work of the workpiece W can be performed more reliably.

When the first correction method is selected, the control device 4 generates a new transport route E3 by combining the transport route E1 and the correction transport route E2, in step S671. Next, in step S672, the control device 4 controls the drive of the robot 2 so that the workpiece W moves along the transport path E3. Through the above steps, the workpiece W is transported to the target position Pe. According to such a method, even if the starting position Ps' deviates from the predicted position Ps, the difference ΔPs between the predicted position Ps and the starting position Ps' is canceled, and the workpiece W can be transported to the target position Pe.

If the second correction method is selected, the control device 4 controls the drive of the robot 2 in step S681 so that the workpiece W moves along the correction transport path E2. Next, in step S682, the control device 4 controls the drive of the robot 2 so that the workpiece W moves along the transport path E1. Through the above steps, the workpiece W is transported to the target position Pe. According to such a method, even if the starting position Ps' deviates from the predicted position Ps, the difference ΔPs between the predicted position Ps and the starting position Ps' is canceled, and the workpiece W can be transported to the target position Pe.

When the third correction method is selected, the control device 4 controls the drive of the robot 2 so that the workpiece W moves along the transport path E1 in step S691. Next, in step S692, the control device 4 controls the drive of the robot 2 so that the workpiece W moves along the correction transport path E2. Through the above steps, the workpiece W is transported to the target position Pe. According to such a method, even if the starting position Ps' deviates from the predicted position Ps, the difference ΔPs between the predicted position Ps and the starting position Ps' is canceled, and the workpiece W can be transported to the target position Pe.

The robot system 1 has been described above. As described above, such a control method for the robot system 1 is a method for controlling the robot system 1 that holds a workpiece W as an object to be transported by the transport device 6 and transports the held workpiece W to a target position Pe. A transport start position prediction step S2 for calculating a predicted position Ps at which transport of the workpiece W to the target position Pe is started, and a transport route generation step S2 for generating a transport route E1 for the workpiece W from the predicted position Ps to the target position Pe. Step S3, a transport start step S5 for starting transport of the held work W to the target position Pe, and correcting the transport path E1 using the difference ΔPs between the start position Ps' at which transport started and the predicted position Ps. A correction step S6 is included. According to such a control method, even if a deviation occurs between the start position Ps' and the predicted position Ps, the deviation is canceled during transport of the workpiece W, and the workpiece W can be transported to the target position Pe. Therefore, the workpiece W can be transported with excellent accuracy.

Further, as described above, in the control method for the robot system 1, the correction step S6 is executed based on the result of comparing the difference ΔPs with a preset tolerance range. For example, when the difference ΔPs is outside the allowable range, the transport route E1 is corrected, and when the difference ΔPs is within the allowable range, the transport route E1 is not corrected. As a result of comparing the difference ΔPs with a preset tolerance range, when correcting the transport path E1, the difference ΔPs between the predicted position Ps and the starting position Ps' is canceled and the workpiece W is moved to the target position. If the work W can be transported to the target position Pe and the transport path E1 is not corrected, the work W can be quickly transported to the target position Pe, and the time required for transport (takt time) can be shortened.

Furthermore, as described above, in the correction step S6, the correction transport path E2 from the start position Ps' to the predicted position Ps is generated, and the transport path E1 is corrected using the correction transport path E2. Thereby, the difference ΔPs between the predicted position Ps and the starting position Ps' can be easily canceled.

Furthermore, as described above, in the correction step S6, the conveyance path E1 is corrected by combining the conveyance path E1 and the correction conveyance path E2. According to such a correction method, the total moving distance of the workpiece W can be shortened compared to the second and third correction methods, and the time required for transport (takt time) can be shortened.

Furthermore, as described above, in the correction step S6, the conveyance path E1 is corrected by adding the correction conveyance path E2 after the conveyance path E1. According to such a correction method, the direction of movement from the starting position Ps' remains the same as the transport path E1, and appropriate transport can be carried out even when there are restrictions on the direction of movement, such as when surrounded by walls on three sides, for example. It can be carried out. In addition, it becomes easier to predict the route, and it is easier to avoid problems such as coming into contact with obstacles during transportation, for example.

Furthermore, as described above, in the correction step S6, the conveyance path E1 is corrected by adding the correction conveyance path E2 before the conveyance path E1. According to such a correction method, the approach direction to the target position Pe does not change, and even when there are restrictions on the approach direction to the target position Pe, such as when the target position Pe is surrounded by walls on three sides, appropriate transportation can be carried out. It can be carried out. In addition, it becomes easier to predict the route, and it is easier to avoid problems such as coming into contact with obstacles during transportation, for example.

Furthermore, as described above, there are a plurality of methods for correcting the transport path E1, and in the correction step S6, one method selected in advance from the plurality of methods is used to correct the transport path E1. In this way, by having a configuration in which the correction method can be selected, the transport path E1 can be corrected using a method suitable for the situation, so that the transport work of the workpiece W can be performed more reliably.

Further, as described above, the control device 4 is a control device for the robot system 1 that holds the work W as an object to be transported by the transport device 6 and transports the held work W to the target position Pe. A transport start position prediction step S2 for calculating a predicted position Ps at which transport of the workpiece W to the target position Pe is started; a transport route generation step S3 for generating a transport route E1 for the workpiece W from the predicted position Ps to the target position Pe; A transport start step S5 in which transport of the held workpiece W to the target position Pe is started, and a correction step S6 in which the transport path E1 is corrected using the difference ΔPs between the start position Ps' at which transport is started and the predicted position Ps. , execute. According to such a control device 4, even if a deviation of the starting position Ps' with respect to the predicted position Ps occurs, the deviation is canceled during transport of the workpiece W, and the workpiece W can be transported to the target position Pe. Therefore, the workpiece W can be transported with excellent accuracy.

Although the control method and control device for a robot system of the present invention have been described above based on the illustrated embodiments, the present invention is not limited thereto, and the configuration of each part may be any configuration having similar functions. It can be replaced with Moreover, other arbitrary components may be added to the present invention.

DESCRIPTION OF SYMBOLS 1... Robot system, 2... Robot, 21... Base, 22... Robot arm, 221... Arm, 222... Arm, 223... Arm, 224... Arm, 225... Arm, 226... Arm, 23... End effector, 3... Imaging Part, 4... Control device, 6... Conveying device, 61... Motor, 62... Belt, 63... Conveying roller, 64... Encoder, 8... Display device, 80... Graphic interface, A... Conveying direction, C... Case, E... Encoder, E1...Transport route, E2...Correction transport route, E3...Transport route, G...Image, J1...Joint, J2...Joint, J3...Joint, J4...Joint, J5...Joint, J6...Joint, M...Motor , Pe...Target position, Pe'...Transportation position, Ps...Predicted position, Ps'...Start position, S1...Workpiece transfer step, S2...Transportation start position prediction step, S3...Transportation route generation step, S4...Workholding step, S5...Transportation start step, S6...Correction step, S61...Step, S62...Step, S63...Step, S64...Step, S65...Step, S66, S671...Step, S672...Step, S681...Step, S682...Step, S691 ...Step, S692...Step, Ti...Image acquisition time, Ts...Operation start time, W...Work, ΔPs...Difference

Claims (8)

A method for controlling a robot system that holds an object to be transported by a transport device and transports the held object to a target position, the method comprising:
a transport start position predicting step of determining a predicted position to start transporting the object to the target position;
a transport route generation step of generating a transport route for the object from the predicted position to the target position;
a transport start step of starting transport of the held object to the target position;
A method of controlling a robot system, comprising: a correction step of correcting the transport path using a difference between the start position at which the transport is started and the predicted position. 2. The method of controlling a robot system according to claim 1, wherein the correction step is performed based on a result of comparing the difference with a preset tolerance range. 2. The method of controlling a robot system according to claim 1, wherein in the correcting step, a correction transport route is generated from the starting position to the predicted position, and the correction transport route is corrected using the correction transport route. 4. The method of controlling a robot system according to claim 3, wherein, in the correction step, the conveyance path is corrected by composing the conveyance path and the correction conveyance path. 4. The method of controlling a robot system according to claim 3, wherein in the correction step, the conveyance path is corrected by adding the correction conveyance path after the conveyance path. 4. The method of controlling a robot system according to claim 3, wherein in the correction step, the conveyance path is corrected by adding the correction conveyance path before the conveyance path. A plurality of methods for correcting the conveyance path are provided,
2. The method of controlling a robot system according to claim 1, wherein, in the correction step, the transport path is corrected using one of the correction methods selected in advance from a plurality of the correction methods. A control device for a robot system that holds an object conveyed by a conveyance device and conveys the held object to a target position, the control device comprising:
a transport start position predicting step of determining a predicted position to start transporting the object to the target position;
a transport route generation step of generating a transport route for the object from the predicted position to the target position;
a transport start step of starting transport of the held object to the target position;
A control device characterized by executing a correction step of correcting the transport route using a difference between a start position at which the transport is started and the predicted position.

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