WO2016067457A1

WO2016067457A1 - Transfer system and method for controlling same

Info

Publication number: WO2016067457A1
Application number: PCT/JP2014/079088
Authority: WO
Inventors: 裕規 ▲高▼山; 掃部　雅幸; 修平倉岡
Original assignee: 川崎重工業株式会社
Priority date: 2014-10-31
Filing date: 2014-10-31
Publication date: 2016-05-06
Also published as: KR20170078789A; CN107073717A; CN107073717B; JP6518263B2; JPWO2016067457A1; KR20190086788A

Abstract

A transfer system (1) is provided with: a hoisting means (2) for hoisting a workpiece (W); guide means (3, 4) for making it possible to horizontally move the hoisting means (2); a robot (5) that moves the workpiece (W) in a state wherein the workpiece is hoisted by means of the hoisting means (2); and a control means (12) that controls the hoisting means (2) and the robot (5). The control means (12) controls a drive source (11) of the hoisting means (2) by means of current control, and also controls a drive source (9) of the robot (5) by means of position control. Workpieces having various weights can be transferred using the robot, while preventing the size and cost of the robot from increasing.

Description

Transport system and control method thereof

The present invention relates to a transfer system for transferring a workpiece and a control method thereof, and more particularly to a transfer system suitable for transferring a heavy workpiece and a control method thereof.

Workpieces that are transported using the transport system include metal molds for manufacturing metal parts, materials before metal parts are molded, or metal parts that make up products. These works weigh hundreds of kilograms. There is something to have.

When transporting such heavy workpieces, for example, the workpiece is lifted by an overhead crane installed in the factory, and the operator operates the traveling mechanism of the overhead crane to move the lifted workpiece to a predetermined position. ing.

In recent years, there has been a demand for unmanned and labor-saving production processes and transport processes by causing a robot to perform various operations that have been performed by workers. For this reason, the use of robots is also being considered for transporting heavy workpieces in manufacturing plants.

However, in order to transport a heavy workpiece with a robot, it is necessary to design and manufacture a robot equipped with a highly rigid arm with a large payload, and the robot itself becomes larger and its manufacturing cost increases. There is a problem.

A technique for solving this problem has been studied. For example, Patent Document 1 proposes a technique for reducing a load on a robot by providing a balancer in a robot so that the work weight is supported by the balancer. .

Japanese Patent Laid-Open No. 9-1492

However, as in the technique described in Patent Document 1, in the configuration in which the work weight is supported by the balancer, the range of the work weight that can be handled is limited by the balancer specifications, and there is a problem that the versatility is poor.

The present invention has been made in view of the above-described problems of the prior art, and enables the transfer of workpieces of various weights using the robot while preventing an increase in size and cost of the robot. It is an object to provide a transport system and a control method thereof.

In order to solve the above-described problem, a first aspect of the present invention is a transport system for transporting a workpiece, in order to enable lifting means for lifting the workpiece and horizontal movement of the lifting means. Guide means, a robot for moving the workpiece in a state of being lifted by the lifting means, and a control means for controlling the lifting means and the robot. The drive source of the means is controlled by current control, and the drive source of the robot is controlled by position control.

According to a second aspect of the present invention, in the first aspect, the control unit supplies a predetermined current value determined in advance according to the weight of the workpiece and the lifting speed of the workpiece to the drive source of the lifting unit. It is comprised so that it may provide, It is characterized by the above-mentioned.

According to a third aspect of the present invention, in the first or second aspect, the control means includes a robot controller for controlling the robot, and the drive source of the lifting means is an external shaft of the robot. As controlled by the robot controller.

According to a fourth aspect of the present invention, in the first or second aspect, the robot control means includes a lifting means controller for controlling the lifting means and a robot controller for controlling the robot. The driving source of the lifting means and the driving source of the robot are cooperatively controlled by communicating between the lifting means controller and the robot controller.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the drive source of the lifting means and the drive source of the robot are both servomotors. .

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the robot is configured to hold the workpiece by holding a workpiece holding jig attached to the workpiece. It is characterized by that.

In order to solve the above-mentioned problem, a seventh aspect of the present invention provides a control method for a transport system for transporting a workpiece, the robot holding the workpiece with a holding step, and before or after the holding step. A lifting step of lifting the workpiece by the lifting means; and a moving step of driving the robot to move the workpiece in a state of being lifted by the lifting means, and driving the lifting means in the moving step The power source is controlled by current control, and the driving source of the robot is controlled by position control.

According to an eighth aspect of the present invention, in the seventh aspect, the holding step is performed before the lifting step, and the drive source of the lifting means is current controlled in both the lifting step and the moving step. And the drive source of the robot is controlled by position control.

According to a ninth aspect of the present invention, in the seventh or eighth aspect, a predetermined current value determined in advance according to the weight of the workpiece and the lifting speed of the workpiece is applied to the drive source of the lifting means. It is characterized by that.

According to a tenth aspect of the present invention, in any one of the seventh to ninth aspects, the drive source of the lifting means is controlled by a robot controller of the robot as an external axis of the robot. .

According to an eleventh aspect of the present invention, in any one of the seventh to ninth aspects, the drive source of the lifting means and the drive source of the robot are a controller for the lifting means, a controller for the robot, It is controlled by performing communication between them.

According to a twelfth aspect of the present invention, in any one of the seventh to eleventh aspects, the drive source of the lifting means and the drive source of the robot are both servomotors. .

The thirteenth aspect of the present invention is characterized in that, in any of the seventh to twelfth aspects, in the holding step, a work holding jig mounted on the work is held by the robot.

In the present invention, “current control” is a control method for controlling the drive current of the drive source, not the amount of operation of the drive source (for example, the amount of rotation of the servo motor). Is used to control the driving force of the driving means of the lifting means when raising, lowering, or resting.

In the present invention, “position control” is a control method for controlling the operation position of the drive source by controlling the operation amount of the drive source (for example, the rotation amount of the servo motor). The position of the held work is controlled.

According to the present invention, it is possible to provide a transport system and a control method thereof that can transport workpieces of various weights using a robot while preventing an increase in size and cost of the robot.

The figure which showed schematic structure of the conveyance system by one Embodiment of this invention. The graph which showed the relationship between the electric current value and tension | tensile_strength in the servomotor for raising / lowering the crane of the conveyance system shown in FIG. The graph which showed the relationship between the electric current value and tension | tensile_strength in the servomotor for raising / lowering the crane of the conveyance system shown in FIG. It is a figure for demonstrating the workpiece conveyance operation | work using the conveyance system shown in FIG. 1, and the figure which showed the state by which the workpiece | work was mounted on the mounting base. It is a figure for demonstrating the workpiece conveyance operation | work using the conveyance system shown in FIG. 1, and the figure which showed the state holding the workpiece | work with the robot. It is a figure for demonstrating the workpiece conveyance operation | work using the conveyance system shown in FIG. 1, and the figure which showed the state which lifted the workpiece | work hold | maintained with the robot from the mounting base. It is a figure for demonstrating the workpiece conveyance operation | work using the conveyance system shown in FIG. 1, and the state which moved the lifted workpiece | work with a robot. The figure which showed an example of the movement path | route at the time of conveying a workpiece | work using the conveyance system shown in FIG. The figure which showed schematic structure of the conveyance system by the modification of embodiment shown in FIG.

Hereinafter, a workpiece transfer system and a control method thereof according to an embodiment of the present invention will be described with reference to the drawings.

The workpiece transfer system and its control method according to this embodiment are particularly suitable for transferring a heavy workpiece.

As shown in FIG. 1, the transfer system 1 according to the present embodiment is incorporated in a robot cell, and includes a crane (lifting means) 2 for lifting the workpiece W. The crane 2 is slidably mounted on a first guide rail 3 installed on the ceiling of the robot cell, and can move in the horizontal direction along the first guide rail 3.

Above the first guide rail 3, two second guide rails 4 are installed in parallel in a direction orthogonal to the extending direction of the first guide rail 3. The first guide rail 3 is slidably mounted on the two second guide rails 4 and is movable along the second guide rail 4 in the horizontal direction. The first guide rail 3 and the second guide rail 4 constitute guide means for enabling the crane 2 to move horizontally in the XY directions.

Note that the guide means in the present embodiment simply allows the crane 2 to move horizontally, and does not have a drive mechanism for causing the crane 2 to travel in the horizontal direction. It is also possible to add a drive mechanism for causing 2 itself to travel in the horizontal direction.

The transfer system 1 according to the present embodiment further includes a robot 5 for holding the workpiece W. The robot arm 6 of the robot 5 has a hand 7 at its tip. The hand 7 is configured to releasably hold the workpiece holding jig 8 attached to the workpiece W.

The robot 5 includes a servo motor (drive source) 9 for driving the robot arm 6 and the hand 7, and the servo motor 9 is provided corresponding to each joint of the robot arm 6 and the holding mechanism of the hand 7. ing. The crane 2 includes a lifting servo motor (drive source) 11 for winding or unwinding the rope 10.

The operation of each servo motor 9 of the robot 5 is controlled by a robot controller (control means) 12. The operation of the lifting / lowering servomotor 11 of the crane 2 is controlled by a robot controller 12 as an external shaft of the robot 5. That is, each of the servo motors 9 of the robot 5 and the lifting / lowering servo motors 11 of the crane 2 are controlled by the robot controller 12.

In this embodiment, the robot controller 12 is configured to control the lifting / lowering servomotor 11 of the crane 2 by current control and to control the servomotor 9 of the robot 5 by position control.

Here, the “current control” is a control method for controlling the drive current of the servo motor, not the rotation amount of the servo motor. In the present embodiment, the work W is raised or lowered by the crane 2, Alternatively, the driving force of the lifting / lowering servomotor 11 at the time of stopping is controlled. That is, the lifting / lowering servomotor 11 of the crane 2 is controlled by current control, and the workpiece W is moved upward with a force (constant for each operation) that balances with the workpiece weight (including the weight of the workpiece holding jig 8). Keep pulling on.

“Position control” is a control method for controlling the operating position of the servo motor by controlling the rotation amount of the servo motor. In this embodiment, the position control of the work W held by the robot 5 is controlled. It is.

The robot controller 12 is configured to apply a predetermined current value, which is determined in advance according to the weight of the workpiece W and the lifting / lowering speed of the workpiece W (including speed 0), to the lifting / lowering servomotor 11 of the crane 2. Yes. The predetermined current value applied to the lifting / lowering servomotor 11 of the crane 2 is obtained in advance by experiments.

By the way, if both the lifting / lowering servo motor 11 of the crane 2 and the servo motor 9 of the robot 5 are driven by position control, there is no problem as long as the operation of the crane 2 and the operation of the robot 5 are completely synchronized. If for any reason (the positioning accuracy of the crane is not sufficient, etc.), there is a shift in the movement between the two, the lifting servomotor 11 of the crane 2 and the servomotor 9 of the robot 5 will be unscheduled as external forces. A load may be applied.

On the other hand, as described above, in the transport system 1 according to the present embodiment, when the work W is transported by the crane 2, the lifting / lowering servomotor 11 of the crane 2 is not “position control” but “current control”. To drive. For example, when a workpiece W having a weight W _i (kg) is lifted by the crane 2 at a speed V ₀ (mm / s), a control method in which a drive current of I ₀ (A) is supplied to the lifting / lowering servo motor 11 of the crane 2. It is. At this time, a predetermined current value I ₀ (A) is given to the lifting / lowering servomotor 11 of the crane 2 regardless of the position of the moving workpiece W. On the other hand, the servo motor 9 of the robot 5 is controlled by position control so that the workpiece W moves at a speed V ₀ (mm / s).

As described above, in the transport system according to the present embodiment, the lifting / lowering servomotor 11 of the crane 2 has a predetermined value determined in advance according to the weight W _i (kg) of the work W and the transport speed V ₀ (mm / s). current value _I 0 flowing (a) of, on the one hand, the work of the servomotor 9 of the robot 5, the speed _V 0 which as a prerequisite in determining the predetermined current value _I 0 (a) (mm / s) Since the movement is controlled so as to achieve the movement, even if the positioning accuracy of the crane 2 is not sufficient, the crane 2 is not position-controlled in the first place, so that no particular problem occurs.

In the transfer system 1 according to the present embodiment, as described above, an unscheduled external force is not applied to the servo motor 9 of the robot 5 during the transfer work of the workpiece W. When an unscheduled external force is applied to the servo motor 9 and an overload occurs in the servo motor 9, the safety mechanism that the robot 5 has as a standard operates to stop the operation of the servo motor 9. .

Hereinafter, the current control of the lifting / lowering servomotor 11 of the crane 2 in the transport system 1 according to the present embodiment will be described in more detail.

First, the current control of the lift servomotor 11 in a state where the vertical position (Z-axis direction position) of the workpiece W lifted by the crane 2 is fixed will be described with reference to FIG.

2, in a stationary state of fixing the vertical position of the workpiece W (crane 2) the (Z-axis direction position), a graph showing the relationship between the current value I _s and the tension T in the lifting servo motor 11 of the crane 2 Yes, it was obtained by experiment. Specifically, the rope 10 of the crane 2 while being fixed to the ground, is obtained by measuring the tension T when changing the current value I _s.

As it is seen from the graph of FIG. 2, in a stationary state, to be in a generally linear relationship between the current value I _s and the tension T has been shown experimentally. That is, a current value I _s in the tension T and the lifting servo motor 11 occurring in the rope 10 can be expressed by the following equation.

In the above equation (1), the coefficients a and b are determined by the specifications of the crane 2 including the lifting servo motor 11.

When the workpiece weight and W _i, when T = W _i, a state of tension T of the crane 2 are balanced and the workpiece weight W _i. Servo motor current I _b in this case is determined as follows.

Then, the workpiece W lifting by crane 2, without changing its vertical position (Z-axis direction position), when moving in the horizontal direction by the robot 5 is balanced with the tension T caused by workpiece weight W _i drive in order to generate a force to lift servo motor 11, to impart current value I _b obtained by putting the workpiece weight W _i in equation (2) to the lifting servo motor 11.

Thus, in the task of conveying the workpiece W in the horizontal direction, the load due to workpiece weight W _i becomes the crane 2 to be borne, it is possible to prevent that such a load on the robot 5.

Next, when the vertical position (Z-direction position) of the workpiece W lifted by the crane 2 is changed, that is, when the workpiece W is moved up and down while the crane 2 and the robot 5 perform the cooperative operation, The current control will be described with reference to FIG.

Figure 3 is a graph showing the relationship between the current value I _m and the Z-axis direction velocity V _z in the lifting servo motor 11 of the crane 2 during cooperative operation, it is obtained by experiments. In the present embodiment, the workpiece is moved up and down under a substantially constant value of the tension generated on the rope of the crane 2 and the workpiece weight.

FIG. 3 shows a case where the workpiece W is raised and a case where the workpiece W is lowered. In the case where the workpiece W is raised, the workpiece W has a workpiece weight W ₁ (kg) and the workpiece W has a workpiece weight W ₂ (kg) (W ₁ > W ₂ ). ing. The case where the workpiece W is lowered indicates the case of the workpiece W having a workpiece weight of W ₁ (kg).

As can be seen from Figure 3, during the Z-axis direction speed V _z of the current value I _m and the workpiece W lifting servo motor 11 of the crane 2 (robot), that there is the following relation shown experimentally .

In the above equations (3) and (4), the coefficients c, d, and e are determined by the specifications of the crane 2 including the lifting servo motor 11.

Since I _b is a function of the workpiece weight _{W i,} if workpiece weight _{W i} and Z-axis velocity _{V z} is known, it is possible to obtain the _{I m.}

Then, in the present embodiment, when the vertically moving the workpiece W, by performing the current I _m under cooperative operation of the lifting servo motor 11 of the crane 2, the robot 5 side without bear workpiece weight W _i A transfer operation is possible.

Next, a control method of the transport system 1 when transporting the workpiece W using the transport system 1 according to the present embodiment will be described with reference to the drawings.

As shown in FIG. 4A, the workpiece W with the workpiece holding jig 8 mounted thereon is mounted on the mounting table 13 in the robot cell. The work holding jig 8 is provided with a grip portion 14 that is gripped by the hand 7 of the robot 5. The robot 5 is driven by the robot controller 12, and the grip portion 14 of the work holding jig 8 is held by the hand 7 of the robot 5 as shown in FIG. 4B (holding process).

Then, by controlling the robot 5 and the crane 2 by the robot controller 12, as shown in FIG. 4C, the workpiece W on the mounting table 13, it lifted at a speed V _z from the initial position P0 to the first position P1 (lifting Process).

In this lifting step, it is calculated based on the equation (3) described above, the current value I _m corresponding to the Z-axis direction speed V _z of the workpiece W, is applied to the lifting servo motor 11 of the crane 2.

Thus, in the lifting process from the initial position P0 to the first position P1, the crane 2 can bear all the total load of the load due to the workpiece weight and the load generated as the workpiece is lifted. Therefore, it is possible to reliably prevent the robot 5 from being overloaded.

When the workpiece W is lifted from the mounting table 13 to the first position P1 in the lifting step, the robot controller 12 controls the robot 5 and the crane 2 to move the workpiece W to a predetermined position as shown in FIG. 4D ( Moving process).

FIG. 5 shows a movement path when the work W lifted up to the first position P1 by the crane 2 is moved to the sixth position P6 by the robot. In FIG. 5, for the sake of convenience of explanation, the movement path of the workpiece W is shown expanded in the same plane, but the actual movement path extends three-dimensionally in the xyz direction.

First, the workpiece W at the first position P1 is moved in the horizontal direction by the robot 5 and moved to the second position P2. In the movement process from the first position P1 to the second position P2, a current value that balances the workpiece weight and tension is applied to the lifting / lowering servomotor 11 of the crane 2 using the above-described equation (2).

Next, the workpiece W at the second position P2 is moved to the third position P3 at a position higher than the second position P2. In the movement process from the second position P2 to the third position P3, the current value corresponding to the speed in the Z-axis direction of the workpiece W calculated using the above-described equation (3) is used as the lifting / lowering servomotor 11 of the crane 2. To grant.

Thereby, in the movement process from the second position P2 to the third position P3, the crane 2 can bear the total load of the load due to the workpiece weight and the load generated as the workpiece is raised. Therefore, it is possible to reliably prevent the robot 5 from being overloaded.

Next, the workpiece W is moved in the horizontal direction from the third position P3 to the fourth position P4. In this movement process, the same control as the movement process from the first position P1 to the second position P2 is performed. Thereby, generation | occurrence | production of the overload in the robot 5 can be prevented reliably.

Next, the workpiece W at the fourth position P4 is moved to the fifth position P5 at a position lower than the fourth position P4. In the moving process from the fourth position P4 to the fifth position P5, the current value corresponding to the speed in the Z-axis direction of the workpiece W calculated using the above-described equation (4) is used as the lifting / lowering servomotor 11 of the crane 2. To grant.

Thereby, in the movement process from the fourth position P4 to the fifth position P4, the crane 2 can be burdened with the total load of the load due to the work weight and the negative load generated as the work descends. Thereby, it is possible to reliably prevent the robot 5 from being overloaded.

Next, the work W at the fifth position P5 is moved to the sixth position immediately below the fifth position P5. In this movement process, the same control as the movement process from the fourth position P4 to the fifth position is performed. Thereby, generation | occurrence | production of the overload in the robot 5 can be prevented reliably.

As described above, according to the present embodiment, since the work W is held by the robot 5 and moved while the work weight is borne on the crane 2, the robot 5 is prevented from being increased in size and cost. However, the workpiece W having various weights exceeding the loadable weight of the robot 5 can be transported without any trouble. In addition, by preventing the robot 5 from becoming large, it is possible to prevent an increase in the area occupied by the robot cell including the robot 5.

According to the present embodiment, the robot controller 12 controls the lifting / lowering servomotor 11 of the crane 2 by current control and the servomotor 9 of the robot 5 by position control. The operation of the lifting servo motor 11 and the operation of the servo motor 9 of the robot 5 can be reliably synchronized. Therefore, it is possible to reliably prevent an overload from being applied to one or both of the lifting / lowering servomotor 11 of the crane 2 and the servomotor 9 of the robot 5.

Moreover, according to this embodiment, since the workpiece | work W lifted with the crane 2 was moved to the horizontal direction with the robot 5, the crane 2 was moved passively to the horizontal direction, Therefore No traveling drive means for traveling the vehicle is required.

In addition, according to the present embodiment, as described above, the crane 2 is passively moved in the horizontal direction in accordance with the horizontal movement of the workpiece W by the robot 5, so that the operation of the drive source of the traveling drive means of the crane 2 is performed. And means for synchronizing the operation of the servo motor 9 of the robot 5 are not required. That is, in this embodiment, the crane 2 simply moves in the horizontal direction following the operation of the robot 5, so the horizontal speed of the crane 2 automatically matches the horizontal speed of the workpiece W.

In addition, according to the present embodiment, both the servo motors 9 of the robot 5 and the lifting / lowering servo motors 11 of the crane 2 are controlled by the robot controller 12, so that the control means of the transport system 1 is compact. In addition, the coordinated control of all the

servo motors

9 and 11 can be performed smoothly.

As a modification of the above-described embodiment, as shown in FIG. 6, a crane controller 15 for controlling the lifting / lowering servomotor 11 of the crane (lifting means) 2 is provided separately from the robot controller 12. You may make it perform cooperative control by communicating between the controller 15 and the robot controller 12. FIG.

In this example, the crane controller 15 controls the lifting / lowering servomotor 11 of the crane 2 by current control, and the robot controller 12 controls the servomotor 9 of the robot 5 by position control. The crane controller 15 and the robot controller 12 share a command (information) related to the weight of the work W to be transported and the lifting speed (Z-axis direction speed), thereby realizing cooperative control between the controllers 12 and 15.

Also in this example, the operation of the lifting / lowering servo motor 11 of the crane 2 and the operation of the servo motor 9 of the robot 5 can be reliably synchronized as in the above-described embodiment. Therefore, it is possible to reliably prevent an overload from being applied to one or both of the lifting / lowering servomotor 11 of the crane 2 and the servomotor 9 of the robot 5.

1 Transport system 2 Crane (lifting means)
3 First guide rail (guide means)
4 Second guide rail (guide means)
5 Robot 6 Robot arm 7 Hand 8 Work holding jig 9 Robot servo motor (drive source)
10 Crane Rope 11 Crane Lifting Servo Motor (Drive Source)
12 Robot controller (control means)
13 Mounting base 14 Handle part of work holding jig 15 Crane controller W Work

Claims

A conveyance system for conveying a workpiece,
Lifting means for lifting the workpiece;
Guiding means for enabling horizontal movement of the lifting means;
A robot for moving the workpiece in a state of being lifted by the lifting means;
Control means for controlling the lifting means and the robot,
The said control means is a conveyance system comprised so that the drive source of the said lifting means may be controlled by electric current control, and the drive source of the said robot may be controlled by position control.
2. The transport according to claim 1, wherein the control unit is configured to apply a predetermined current value determined in advance according to a weight of the workpiece and a lifting speed of the workpiece to the drive source of the lifting unit. system.
The control means has a robot controller for controlling the robot,
The transport system according to claim 1, wherein the drive source of the lifting means is controlled by the robot controller as an external axis of the robot.
The robot control means has a lifting means controller for controlling the lifting means, and a robot controller for controlling the robot,
The transport system according to claim 1 or 2, wherein the drive source of the lifting means and the drive source of the robot are cooperatively controlled by performing communication between the lifting means controller and the robot controller.
The transfer system according to any one of claims 1 to 4, wherein each of the drive source of the lifting means and the drive source of the robot is a servo motor.
The transfer system according to any one of claims 1 to 5, wherein the robot is configured to hold the workpiece by holding a workpiece holding jig attached to the workpiece.
A control method of a transfer system for transferring a workpiece,
A holding step of holding the workpiece by a robot;
A lifting step of lifting the workpiece by a lifting means before or after the holding step;
A moving step of driving the robot and moving the workpiece in a state of being lifted by the lifting means,
In the moving step, a control method of the transport system, wherein the drive source of the lifting means is controlled by current control and the drive source of the robot is controlled by position control.
The holding step is performed before the lifting step,
8. The method of controlling a transfer system according to claim 7, wherein in both the lifting step and the moving step, the drive source of the lifting means is controlled by current control, and the drive source of the robot is controlled by position control.
9. The method of controlling a transfer system according to claim 7 or 8, wherein a predetermined current value determined in advance according to the weight of the workpiece and the lifting speed of the workpiece is applied to the drive source of the lifting means.
10. The method of controlling a transport system according to claim 7, wherein the drive source of the lifting means is controlled by a robot controller of the robot as an external axis of the robot.
The drive source of the lifting means and the drive source of the robot are coordinated and controlled by performing communication between the controller for the lifting means and the controller for the robot. The method for controlling the transport system according to one item.
The method for controlling a transport system according to any one of claims 7 to 11, wherein each of the drive source of the lifting means and the drive source of the robot is a servo motor.
The method of controlling a transfer system according to any one of claims 7 to 12, wherein in the holding step, a workpiece holding jig mounted on the workpiece is held by the robot.