JPH04307602A - Industrial robot control method - Google Patents

Abstract

PURPOSE:To easily express the designation of operating speed of an external device of a robot when this external device is actuated. CONSTITUTION:The external device operating speed command value outputted from a robot control device 2 when an external device 3 is actuated at a prescribed speed is stored as the defined motor speed command value. When the device 3 is controlled by a program, an external device operating speed instruction contained in the program is converted based on the defined motor speed command value, so that the speed command value is obtained to the device 3. Then the external device operating speed instruction can be written into the program with the operating speed VX of the device 3 kept as it is.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is a method for controlling an industrial robot in which the control of the robot body and the control of external devices for controlling the workpiece position, such as a positioner and an index table, are operated by the same program. Regarding.

0002

[Prior Art] Industrial robots include not only systems that work on fixed workpieces, but also systems that perform work by cooperatively controlling the movement of the robot body (manipulator) and the position of the workpiece. However, systems that perform such cooperative control are equipped with external devices called positioners and index tables that control the position of the workpiece, and these are controlled together with the robot body by the same program. has become,
At this time, in such a robot system, external devices such as a positioner and an index table that are combined therein are equipped with a servo motor as an actuator, and this servo motor is driven and controlled by a robot controller via a servo amplifier. is common.

By the way, when specifying the operating speed of an external device in a program that controls the operation of such a robot and an external device, the speed command can be expressed by the rotational speed of a driving servo motor. can. Since the servo motor uses a pulse encoder as its position detector, the rotational speed of the servo motor is expressed by the number of changing pulses per unit time [pulses/second].

Therefore, when assuming a certain external device and specifying its operating speed, first, from the mechanical structure of the external device, etc., the rotational speed f of the servo motor corresponding to the operating speed vx is determined. Find (vx). However, this f(vx) is a function of the operating speed vx, and its unit is [revolutions/second], so it cannot be written in a program as is. Therefore, in order to express this in units of [pulses/second], as shown in equation (1), the servo motor 1
It is necessary to convert it into the servo motor rotational speed vp in units of [pulses/second] by multiplying it by the number of pulses kp for the rotation.

[0005] vp=f(vx)×kp

---(1) Normally, the operating speed vx of the external device and the rotational speed f(vx) of the servo motor are often in a proportional relationship, and in that case, equation (1) is
Using m, the equation (2) is obtained. vp=vx×km×kp

---(2) As described above, in the conventional technology, when describing the operating speed of an external device in a program, [
It was described in terms of servo motor rotation speed vp in units of [pulses/second].

[0006]

[Problems to be Solved by the Invention] In the above-mentioned prior art, when specifying the operating speed of an external device in a program, the rotation speed of the servo motor that drives the external device is changed to [pulse/
seconds].

[0007] By the way, when creating such a program, it is necessary to work while envisioning the actual working conditions, but what the operator actually needs at this time is the operating speed of the external device. However, it is quite difficult to recognize this from the rotational speed of the servo motor, which is simply a means to drive an external device, and therefore, with the conventional technology, it is quite difficult to create a program. there were.

[0008] Furthermore, it is not easy to calculate the rotational speed of the servo motor from the operating speed of the external device, and there is also a problem that an error occurs between the relational expression and the actual mechanical structure.

Furthermore, in such robot systems, the external devices such as positioners and index tables that are combined therewith are not always the same, and are often arbitrarily selected and unspecified devices. but,
In this case, there is a further problem in that it becomes difficult to recognize the operating speed of the external device from the rotational speed of the servo motor described above.

[0010] An object of the present invention is to solve the problems of the prior art, and to facilitate the expression of the operation speed specification of an external device in a program when operating an external device such as a positioner or an index table. The objective is to provide a control method.

[0011]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a method for defining an external device speed command value output from a robot control device when the external device is operated at a preset speed. It is stored as a speed command value, and when the external device is controlled by the program, the external device operating speed command in the program is converted by the defined motor speed command value to obtain the speed command value for the external device. This is what I did.

0012

[Operation] Definition of external device The motor speed command value is set by increasing or decreasing the operating speed of the external device while operating it, adjusting it to a certain speed Vx, and then numerically controlling the speed Vx at that time from the operating device. It is memorized by inputting it.

When the program is executed, the external device speed command vx causes the robot control device to issue a motor speed command to the external device proportional to the motor speed command value Vc when the speed of the external device is defined. The value vc is output, and the motor speed command value vc at this time is expressed by the formula (
3).

vc=(vx/Vx)×Vc

--- (3) Therefore, in the program, an external device speed command can be written that instructs the external device operating speed vx as it is.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of controlling an industrial robot according to the present invention will be explained in detail below using the illustrated embodiments.

First, FIG. 2 is a schematic configuration diagram showing an example of a robot device to which the present invention is applied. As shown in this diagram, a robot main body 1 and an external device 3 are connected to a robot control device 2. The operations of the robot main body 1 and the external device 3 are cooperatively controlled by the robot control device 2.

The external device 3 is a device that performs rotational or linear motion, such as a workpiece that the robot body 1 works on, some device related thereto, or a positioner or a traveling device that moves the robot body 1 itself.

Here, the robot main body 1 and the robot control device 2 are combined as a pair, and are a single set of products as a whole. is a completely different product.

Next, FIG. 1 is a block diagram of a robot control device 2. This robot control device 2 is capable of creating a program that describes a series of operations of the robot body 1 and external device 3 point by point, and Execute and robot body 1
and functions to cause the external device 3 to operate as described in the program. device speed conversion means 26;
It is composed of a defined speed storage means 27, an external device speed definition means 28, an operating device 29, and a display device 20.

The relationship between the robot main body 1 and the robot control device 2 in this embodiment is a typical teaching/execution method, in which a program is created by teaching the robot's movements, and the robot is controlled by executing the program. Main body 1
Have the student reproduce the taught action.

The program at this time is created by the teaching means 23 by the operator operating the operating device 4, but this program includes not only the operation of the robot body 1 but also the operation of the external device 3. Various instructions related to this are described, and these instructions include an instruction for specifying the operating speed of the external device 3.

Furthermore, FIG. 3 shows the configuration of the external device 3, which includes an operating section 31 that performs rotational or linear motion, and a servo motor 3 that drives the operating section 31.
3. A motion transmission section 32 that transmits the power of the servo motor 33 to the motion section 31, and a servo motor drive device 3 that drives the servo motor 33 according to instructions from the robot control device 2.
It consists of 4. Then, the motor speed command value vc is output from the robot control device 2 to the servo motor drive device 34, and the servo motor 33 rotates at a speed proportional to this motor speed command value vc. Since the operating speed vx of the operating section 31 is proportional to the rotational speed of the servo motor 33, it is also proportional to the motor speed command value vc.

Note that the motion transmission section 32 not only transmits the power of the servo motor 33 to the motion section 31, but also transmits it by changing the rotation ratio or direction of rotation, or by changing rotational motion into linear motion. There is also. Here, since the external device 3 is constructed separately from the robot main body 1 and the robot control device 2, the mechanical structure of the external device 3 is completely unknown to the robot control device 2.

Next, FIG. 4 is an operation flow showing an outline of the overall operation procedure of the above embodiment, in which an external device speed definition step 41 is first carried out, and then a teaching step 42 and an execution step 43 are carried out. These steps are now being carried out, and these steps will be explained one by one below.

FIG. 5 is an operation flow showing the external device speed definition step 41 in more detail. This external device speed definition step 41 is executed by the external device speed definition means 28. In the speed adjustment step 51, the operator operates the operating device 29 to actually operate the external device 3 and adjusts its operating speed to a certain representative speed. The speed at this time is defined as the defined speed Vx.

Then, at this time, the motor speed command value vc should have been output from the robot control device 2 to the external device 3, and this motor speed command value vc is stored as the defined motor speed command value Vc in the defined speed storage means. 2
7 is stored.

Next, the process proceeds to a defined speed input step 52, in which the operator inputs a numerical value representing the defined speed Vx from the operating device 29. For example, if the speed is 500mm/s, enter 500, and if the speed is 3000rpm, enter 3000.
Enter The speed unit at this time may be arbitrary. The input numerical value is stored in the defined speed storage means 27 as the defined speed Vx.

Next, in the defined speed unit input step 53, the operator inputs the unit U expressing the defined speed Vx from the operating device 29 as a character string. As an example, 500mm/s
If so, enter mm/s, and if it is 3000 rpm, enter r
Enter pm. The input character string is stored in the defined speed storage means 27 as the unit U of the defined speed Vx.

FIG. 6 is an operation flow showing the teaching step 42 in more detail. The teaching step 42 is executed by the teaching means 23 and is composed of one or more instruction writing steps 61. That is, in these instruction writing steps 61, the operator operates the operating device 29 to select one of the plurality of types of instructions 71, writes them sequentially to create a program, and writes the program 7 into a program. Storage means 24
to be memorized. At this time, the described command 71 is displayed on the display device 20.

By the way, these instructions 71 are a series of operations of a robot or an external device classified into each operation element, and therefore, the program 7 can be executed by one or more instructions as shown in FIG. The instruction description steps 61 to which the instructions 71 correspond are combined as executed.

There are various types of commands 71 for controlling the operation of a robot or an external device, including an external device speed command 72 that specifies the operating speed of the external device 3. , and an external device operation instruction 73 that instructs the external device 3 to perform an operation. Among these, the external device operation instruction 73 is a command that causes only the external device 3 to operate. Alternatively, the command may be a command that causes both the external device 3 and the robot body 2 to operate. Note that the external device speed command 72 and the external device operation command 73 are both types of commands 71.

By the way, in the command description step 61, the external device speed command description step 62 describes the external device speed command 72, and the external device operation command description step 62 describes the external device operation command 73. 63, these external device speed command description step 62 and external device operation command description step 6
3 may be performed multiple times in the teaching step 42. In this case, the program 7 includes a plurality of external device speed commands 72 or external device operation commands 73. However, before the first external device operation command description step 63, the external device speed command description step 63 must be performed.
must be carried out. Therefore, in the program 7, the external device speed command 72 must be written before the first external device operation command 73.

In the external device speed command description step 62, as shown in FIG. Select attached device speed command 72. At this time, the display device 20 displays an external device speed command word indicating that it is the external device speed command 71 in the form of a character string.

Next, in the command speed input step 82, the operator operates the operating device 29 to input a numerical value representing the command speed vx at which the external device 3 is to be operated. The input numerical value is determined by the external device speed command selection step 81.
It is written in the program 7 as an external device speed command 72 together with the external device speed command word displayed in , and is stored in the program storage means 24 . At this time, the input numerical value is displayed on the display device 20 following the external device speed command word displayed in the external device speed command selection step 81.

Furthermore, in the commanded speed unit display step 83, the unit U input in the defined speed unit input step 53 is displayed on the display device 20, following the numerical value displayed in the commanded speed input step 82, and the unit U input in the defined speed unit input step 53 is displayed. The device speed command description step 62 ends.

As described above, if the instruction writing step 61 is repeated as many times as necessary and the teaching step 42 is completed, the creation of the program 7 is completed. Then, the process can proceed to execution step 43 of operating the external device.

In this execution step 43, first, the execution means 23
, the program 7 is read from the program storage means 24 and each instruction 7 written in the program 7 is read out.
1 are interpreted in the order in which they are written, and the robot main body 1 and external device 3 are operated as indicated by the instructions 71. Each of these operations is well known in robot control, and is not directly related to the present invention, so a description thereof will be omitted.

First, in the execution step 43, among the instructions 71, an external device speed instruction 72 and an external device operation instruction 73 are executed.
The operation when interpreted is explained below.

When the external device speed command 72 is interpreted, the external device speed conversion means 26 converts the command speed vx of the external device speed command 72, the defined speed Vx stored in the defined speed storage means 27, and the definition. Motor speed command value V
From c, the motor speed command value vc is calculated as shown in the above equation (3) and stored in the motor speed command value storage area of the defined speed storage means 27.

Next, when interpreting the external device operation command 73 and causing the external device 3 to perform some operation, the external device 3
Then, the motor speed command value vc stored in the motor speed command value storage area of the defined speed storage means 27 is output.

Then, from equation (3), the servo motor 33 rotates at a speed vx/Vx times the defined motor speed command value Vc in the external device speed definition step 41, so in the end, the external device 3 vx/Vx of speed Vx
Therefore, according to this embodiment, by simply writing the command speed vx at which the external device 3 is to be operated as it is in the program, the external device 3 can be operated at that speed. 3 control can be obtained.

[0042]

According to the present invention, in a device that controls the motion of a robot and an external device, when specifying the speed of the external device in a program that controls those motions, the speed of the external device is Regardless of the internal structure of the external device, the actual speed that you want to operate can be described in the program, so each time you specify the speed of an external device, the rotational speed of the servo motor that drives the external device will be changed. There is no need to calculate , and the work can proceed at a speed that is intuitive and easy for the operator to understand.Therefore, the number of man-hours required for program creation is reduced, and the creation work is easy.
This has the effect of reducing the time required.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a robot control device in an embodiment of an industrial robot control method according to the present invention.

FIG. 2 is a configuration diagram showing an example of an industrial robot device to which an embodiment of the present invention is applied.

FIG. 3 is a configuration diagram of an external device in an embodiment of the present invention.

FIG. 4 is a flowchart outlining the overall operating procedure in one embodiment of the present invention.

FIG. 5 is an operation flowchart illustrating an external device speed definition step in an embodiment of the present invention.

FIG. 6 is an operation flowchart illustrating a teaching process in an embodiment of the present invention.

FIG. 7 is a configuration diagram of a program in an embodiment of the present invention.

FIG. 8 is an operation flowchart illustrating an external device speed command writing step in an embodiment of the present invention.

[Explanation of symbols]

1 Robot body 2 Robot control device 3 External device 7 Program 20 Display device 21 Robot body control means 22 External device control means 23 Teaching means 24 Program storage means 25 Execution means 26 External device speed conversion means 27 Definition speed storage means 28 External device speed definition means 29 Display device 31 Operating part 32 Motion transmission section 33 Servo motor 34 Servo motor starting device 41 External device speed definition process 42 Teaching process 43 Execution process 51 Defined speed adjustment process 52 Definition speed input process 53 Defined speed unit input process 61 Instruction description process 62 External device speed command description process 63 External device operation command description process 71 Command 72 External device speed command 73 External device operation command 81 External device speed command selection process 82 Command speed input process 83 Command speed unit display process.

Claims (1)

[Claims] [Claim 1] A method for controlling an industrial robot in which a robot body and an external device for controlling the workpiece position are controlled under the same program, the external device being operated at a preset speed. When the external device speed command value output from the robot control device is stored as the defined motor speed command value, and when the external device is controlled by the program, the external device operating speed command in the program is stored as the defined motor speed command value. A control device for an industrial robot, characterized in that the control device is configured to convert the value into a speed command value for the external device.