JPS59218502A - Safety device for industrial robot - Google Patents

Abstract

PURPOSE:To avoid effectively a dangerous state of the robot by giving an alarm to stop the actions of a robot in case the difference between the address of the start point or an intermediate stopping position of the robot and the data on the destination address exceeds the prescribed allowance step value. CONSTITUTION:The destination address of an arm (not shown in the diagram), etc. is set to an address A register 3 with operation of an address switch 2a. An address B register 4 stores the address of the start point or the present stop position of a robot from a robot main control part 1. A computing element 5 obtains the difference between both registers 3 and 4 from calculations, and a comparator 6 compares said difference with an allowance step set by an allowance step setting switch 7. If the difference exceeds the allowance step, an alarm 8 is delivered. At the same time, the operation inhibiting signal is set to the part 1. In such a way, a misoperation is prevented with robot teaching and at the same time the safety of an operator is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a safety device for an industrial robot.

Normally, industrial robots are taught their work movements in advance through teaching work, but if there is a problem with a part of the taught work movement11, the work movement in that section is re-taught. There is.

By the way, when performing a partial correction of this work motion, if the trajectory of the robot's arm becomes too far away from the originally taught trajectory, it will be very dangerous for nearby workers. This problem is particularly important because input errors are likely to occur with special numbers (ropo, which uses a keyboard for teaching).

Therefore, in order to solve the above problem, in the past, when the arm actually moves to the location specified by the guard/destination address data, the difference in distance from the current value (initial arm position) is determined by a predetermined value. There are some that issue an alarm when the number of bits is exceeded, and some that set the movable range of the arm in advance to a valid address (
Am to An), and specify the destination address (A
c) exceeds a effect 7 dress (Ac<Am or An
<Ac) There is something that will cause an alarm.

However, in the former case, it is not known whether or not there is a problem with the destination address until the arm force (movement 1.) is actually applied, so there is a problem that the teaching work efficiency is low, and it is dangerous because the arm ends up moving. In the latter case, the arm will operate unconditionally even if the destination is extremely far away from the current location as long as it is within the range of valid addresses, making it unsafe. There was a problem that it was not desirable.

In view of the above, it is an object of the present invention to provide a safety device for an industrial robot that can prevent setting errors in teaching and teaching correction work and improve the safety of workers and the like.

In order to achieve the above-mentioned object, the present invention provides an industrial robot in which a glance report is issued when the value of destination address data indicating the robot's destination is larger than the current value address data indicating the robot's current position by a predetermined value or more. The robot is characterized by a safety device configured to prevent the robot from operating.

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

In the figure, numeral 1 indicates a main control section of a well-known playback type robot. For example, other control sections as shown in FIG. 6 are added to constitute the entire robot.

To explain this a little further, from the teaching operation panel 2, an arm (not shown) driven by a servo mechanism can be freely operated. This operation command is determined by the four-bot main control section 1 and output as a movement command to the device control section 1C. This command is sent to the speed control section 1D as a pulse signal for controlling the moving axis, and the motor M is driven. On the other hand, this movement path is determined by the robot main control unit 1 and recorded in the storage device 1E. Further, in conjunction with this, the teaching pendant 2 can also instruct the mechanical hand 1H and the like to operate, and can also send and receive operation signals to and from the partner machine 1G and the like. These signals are also stored in the storage device 1E together with data regarding the operation path. That is, the results of operating the four bots by manual operation are stored in the storage device 1E. Then, during automatic operation, the contents related to the operation procedure stored in the storage device 1E are sequentially retrieved to the four-bot main control section 1, and each section is sequentially operated according to future commands. That is, the motion set by the teaching work is reproduced.

Next, the main parts of the present invention will be explained. The teaching operation panel 2
In this example, the address set switch 2a shown in FIG.
is provided. This is used to store arbitrary destination address data indicating the destination of an arm (not shown) in the address register 3.
It consists of a keyboard, etc., for making settings.

The address register 6 mainly transmits the address data set by the address set switch 2a to the register 5.
This is a register for transferring to.

Note that this address person register 6 is stored in the robot main control unit 1.
It also has the function of transferring data to and address B register 4.

The address B register 4 contains current value address data indicating the position of the arm, etc. at the start of movement, or the same arm when the movement of the arm, etc. is stopped midway in order to correct the trajectory of the arm, etc. during playback operation. This is a register for extracting current value address data indicating the current position from the robot main control unit 1 and temporarily holding it.

The arithmetic unit 5 calculates the destination address data Ac set in the addressee register 6 and the address B register 4, respectively.
and the current address value Ap (Sob=
This is for calculating IAp-Acl) and transferring the calculation result to the comparator 6.

The allowable step setting switch 7 is provided, for example, on the oU teaching operation panel 2, etc., and sets a predetermined allowable step value to the comparator O (this indicates the moving distance of the arm, etc.). (set numerically) can be set. Note that once this allowable step value C is set, that value is continuously held until it is set again.

The comparator 6 compares the allowable step value t set by the allowable step setting switch 7 with the difference Sob,
When the result is Sob≧ε (Sob>ε may also be acceptable), an alarm instruction signal is sent to the alarm device 8.

The alarm device 8 issues an alarm when the alarm instruction signal is input from the comparator 6, and also sends a prohibition signal to the four-pot main control section 1 to prohibit the operation of the robot. Note that the notification is notified to the worker by lighting a lamp or sounding a buzzer.

In the above configuration, first, playback operation in playback mode (
Confirmation of teaching operation) Assuming the start, the operator instructs the robot to the next position to which the arm, etc. should move, using the teaching operation panel 2 or the like. Specifically, this is accomplished by setting the destination of the arm as destination address data Ac for an address set switch 2a provided on the teaching pendant 2 or the like. At this time, the destination address data Ac set in the address set switch 2a is transferred to the address input register 6, and the position of the arm, etc. at the start of the playback operation is indicated by the robot main control unit 1 to the address B register 4. Current value address data AP is transferred.

Then, these two data Ac, +Ap are calculated by the arithmetic unit 5.
The difference Sob between both data is calculated. This difference Sob is then transferred to the comparator B, and the allowable step value ε set by the allowable step setting switch 7
A comparison is made with (The allowable step value ε is preset to 0, and if the result of this comparison is Sob≧ε, an alarm instruction signal is sent to the alarm device 8 to notify the operator, and the robot If the worker sets the destination address data in the address set switch 2a and the robot issues an alarm, it means that the destination address data was inappropriate, and the worker must set the destination address data again to the proper destination address data. All you have to do is reset the settings and continue the playback operation.From then on, the same judgment is made every time the destination address data is set to ensure the safety of the workers.It should be noted that the arm A similar determination is made when a partial correction is made to a trajectory such as the following.In this case, the position data of the arm, etc. when the robot is stopped for partial correction is transferred to the address B register 4 as the current value address data. Ru.

In the above description, a case where the robot main control unit 1 is directly controlled by software will be explained. however,
In the following explanation, the CP built in the robot main control unit 1 is
Assume that U is of a type having register A configured as an accumulator and general-purpose register B.

First, when destination address data Ac is input by operating the teaching pendant 2 during playback operation, this is read in step 1 as shown in Figure 2, and transferred to the A register in the CPU in step 2. and retained. When this is completed, the process proceeds to step 6, where current value address data Ap indicating the current position of the arm is read, and in step 4, it is transferred to and held in the B register in the CPU. Next step 5
Then, the difference IAp-Act between the content Ac of the A register and the content AP of the B register is calculated (the result of this calculation is automatically stored in the A register), and when this is completed, the process advances to step 6 and the allowable step value ε is calculated. Loading is performed.

Next, in step 6, the allowable step value ε is transferred to the B register, and in step 8, the contents of the A register IAP-
A comparison is made between Acl and the contents ε of the B register. In this soft ratio, in the case of A2B (lAp-Acl≧ε)
If so, the process proceeds to step 9 to issue an alarm output, and if A<H, the process directly returns to the predetermined location.

It should be noted that the allowable step value ε is set in advance by the teaching operation ';A2'', etc., as in the case of the above-mentioned Norsick method.Furthermore, the determination in step 8 may be made such that A>B. In addition, the alarm output in step 9 is a sound,
This provides a light warning and prohibits the robot from operating. 1 In this way, in this example, when the value of the destination address data set during the playback operation is larger than the current value address data indicating the current position of the arm, etc. by a predetermined value or more, an alarm is issued and the robot is activated. Since the operation is prohibited, the movement range of the arm etc. is always within a predetermined range when performing the next operation from a certain stop position, so safety is further improved than before. Moreover, unlike conventional systems where an alarm is issued as a result of the actual movement of the arm, when destination address data Ac is input, it is immediately determined whether the input value is an appropriate value or not. This feature allows teaching work to be performed more efficiently.

That is, the present invention provides a safety device for an industrial robot that includes means for storing current value address data indicating the start or intermediate stop position of the robot, and destination address data indicating the destination from this current value address data. means for setting a predetermined allowable step value; means for calculating a difference between the destination address data and the current address data; and a means for comparing the difference with the allowable step value. By having a configuration that includes means for issuing an alarm instruction signal when the difference is larger than the allowable step value, and means for issuing an alarm or stopping the robot in response to this alarm instruction signal, setting errors during teaching work can be avoided. It has the excellent feature of being able to prevent accidents and further ensure the safety of workers, etc.

[Brief explanation of drawings]

The drawings show embodiments of the present invention, 8)! Figure 1 is a block diagram showing an embodiment of the /...-do four chic in the present invention, Figure 2 is a block diagram showing an embodiment of the Arco°1 nosm in the present invention.
- Chart, FIG. 6 is an explanatory diagram showing four industrial pots. 1...Robot main control unit 6...Address A register 4...Address B register 5...Arithmetic unit 6...Comparator 8...Alarm device quantity Request person Toshiyu Automobile Co., Ltd.

Claims (1)

[Claims] Means for storing current value address data indicating a start or intermediate stop position of the robot; means for storing destination address data indicating a destination of the stomach bot based on the current value address data; and a predetermined allowable step. means for setting a value; means for calculating the difference between the destination address data and the current value address data; and a means for comparing this difference with the allowable step value and generating an alarm when the difference is greater than the allowable step value. means for emitting an instruction signal;
A safety device for an industrial four-bot, characterized by having means for issuing an alarm or prohibiting operation of the robot in response to the alarm instruction signal.