JPS5857762B2 - Method and device for correcting movement speed in robots - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for numerically controlling the simultaneous movement speed of a moving object in multiple axial directions, and particularly to a method for correcting and teaching the movement speed, a method for storing and reproducing the movement speed, and an apparatus therefor.

When performing arc welding on an industrial robot by moving a moving object such as a processing head or a workpiece (for example, a robot arm) along a complicated path such as the welding line path of arc contact, welding Teaching the route and teaching (control) the moving speed
However, in this case, even if perfect constant speed control is possible, it is necessary to adjust (increase or decrease) the moving speed according to changes in the plate thickness or groove of the workpiece to be welded.

In addition, in an ordinary welding machine (low-grade machine), several types of variable speeds are set in advance, and the set values are selected appropriately to obtain changes in speed.

However, the above method is unsatisfactory for work such as arc welding with complex shapes, and requires an optimum torch movement speed for each section, but there has been no simple method to meet this objective.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method and apparatus for correcting the moving speed of a robot, which allows speed correction to be performed accurately and efficiently, and which reduces loss of sales during correction work.

Next, the concept of the information correction/teaching method according to the present invention will be explained.

In other words, while actually moving a multi-directional moving object using polygonal line approximation using already taught position information and movement speed information, after increasing, decreasing, or multiplying the required amount Vc in the movement speed information Vold read from past memory. While moving the moving object with the numerical value Vnew, the operator executes arc welding or other necessary work purposes, and while determining whether the result of the work is appropriate, the operator issues teaching commands and adjusts the movement speed. This is a method of rewriting information, and the formula that is executed is shown below.

In addition, a series of line segment velocities are updated by the sequential operation, and if necessary, in addition to the above-mentioned movement speed, arc welding wire feed speed information and the like are updated in the same way.

If one correction instruction is not sufficient, repeat the instruction many times.
Learning and teaching.

It goes without saying that the above method can be applied not only to the moving speed but also to the coating discharge amount, the welding wire feed-out speed, gas cutting, etc.

Next, it will be explained in more detail.

FIG. 1 is a block diagram of an embodiment according to the present invention, and FIG. 3 is a vector diagram thereof.

When an object moving in a multi-axis direction is capable of linear motion in the X- and Y-coordinate directions and rotational motion θ around the Z-coordinate axis, and moves at a composite vector movement speed of X-Y・θ, the movement path position information and A storage circuit 1 that stores movement speed information for each section receives a signal NEX from a movement speed calculation circuit 19, which will be described later.
When receiving T, the next position storage information Xn + I Yn + 1 and θn + 1 and section movement speed storage information Vn + 1 are selected from the information group that has been taught so far.
.

and sends out left-right position information cw indicating that the workpiece is on the right or left with respect to the moving direction.

On the other hand, 2, 3, and 4 are current position sensors for a straight position on the X-seat table axis and a rotational position around the Z coordinate, respectively.

These are the information from the memory circuit 1 that transmits the current position information and 7 create a residual.

Next, the digital signals are converted by D/A converters 8, 9, and 10 into analog residual symbols such as voltages ΔX, ΔY, and Δθ.

The moving speed corrector 11 is composed of two contact pieces 12 and 13 as shown in FIG. has a structure in which it makes contact for the first time at the stroke end, and the corrected moving speed information is stored in the storage circuit in collaboration with the signal WRiTE generated at this time and the signal NEXT from the moving speed calculation circuit 19, which will be explained later. Write.

When the contact piece 12 makes contact, the speed correction amount setter 14! obtains the speed correction setting value dv.

If this DV is a digital quantity, use it as is for △■,
If it is an analog quantity, the A/D converter 15 obtains Δ■.

This △■ and the information sent out from the memory circuit 1 Vn+ 1
New section movement speed information VNEW=Vn+1.+Δ■ is obtained by the digital addition 7 circuit 16 that adds the values.

The new movement speed information VNBW is obtained from the analog movement i speed information (2) which is given to the movement speed calculation circuit 19 through the D/A converter 17 and, if necessary, the exponential function generator 18'.

The movement speed calculation circuit 19, which receives the above-mentioned inputs △X, △Y, and △θ, and the correction amount ■, performs calculations that satisfy the following formula, and calculates each coordinate axis movement speed signal ■X, VY, and ■
Output θ.

The movement speed signals of each coordinate axis (X, VY, and ■θ) are input to a drive circuit such as a pulse motor, and the object moving in multiple axes continues to move toward the next destination Pn+1 at the new movement speed.
Eventually, analog human power △X and △Y will both be 0 = (△XY =
0), the same moving speed calculation circuit 19 outputs a signal NE.
XT is transmitted.

When the movement speed correction command device 11 is strongly pushed to the stroke end, the contact piece 13 comes into contact and a new section movement speed rewrite command WRiTE is output.

When this command W Ri T E coincides with the previous signal NEXT in the control circuit 20 , new section movement information VNEW is written into the storage circuit 1 .

The other signal NEXT is the next movement target position information Xn+2・Y
n+2·, θn+2, and moving speed information Vn+2 are read from the storage circuit 1.

In this way, the moving speed information is corrected and stored for each section.

Similarly to the above, in the case of correction of the welding wire feed-out speed, 2
Satisfactory results are obtained at 1, 22.23, and 24.25.

Next, its effect will be explained.

When working with a pseudo Cp (Continuos pass) type, when increasing or decreasing the movement speed of a part, rather than completely rewriting the movement speed information, it is better to increase or decrease the current speed of that part or a certain range. It is efficient to adjust (increase or decrease) the movement speed using the movement speed information between the line segments of 15 is activated and the moving speed of Vn-1-■ is V N EW = V
Corrected according to n + 1 + △■.

If the result is good, when the movement speed correction command device 14 is pushed again, the information of VNEW is stored in the storage circuit 1 as new section movement speed information by the control circuit 20.

In this case, for the sake of simplicity, the movement speed correction command device 13 can be used even in one-stage operation.

In addition, in order to store the moving speed information densely at low speeds and coarsely at high speeds, when passing through the exponential function generator 18, new moving speed information speed VNEW=V01dXEXP(△■)ξVold
X (mez W) is obtained.

Further, the structure and operation of an embodiment of a porta-pull type operating device for performing the above-mentioned operations will be described below.

The configuration shown in Figure 4-1 is the speed correction amount setting device 14 at your fingertips.
This is an example of an operating device that teaches correction of the moving speed of a line segment by rotating the position correction command device 11 with the palm of the hand and pressing the position correction command device 11 with the palm of the hand. 12.13 is separated and installed on the same axis as the speed correction amount setting device 14, the correction amount is set by rotation, and by pushing the coaxial, a closed circuit is formed via the contact piece 13 and a memorized command is output. The other contact piece 12 is an example of an actuator in which the selection is made by a separate speed modification selection switch.

In addition, information other than the movement information of objects moving in multi-axis directions, such as the feed-out speed information of the arc welding wire during carbon dioxide arc welding work, can be used instead of the information Vn+1 in Figure 1 to correct and teach SW while observing the welding state. Wire unwinding speed information ■Read as WS, correction command device 11 in the diagram, D/A
This is possible if 21, 22, 23, 24, and 25 corresponding to the converter 17 are prepared.

In addition, in FIG. 1, an A/D converter 15, a digital adder 16,
Although the D/A converter 17 is used, the function of this circuit is of course the same as that of a D/A converter, an analog adder, or an A/D converter as an analog addition method.

That is, with the configuration described in the claims, the present invention erases incomplete information that has already been taught and sets new taught information, unlike the conventional method, which erases incomplete information that has already been taught and sets new taught information. Using the information and movement speed information, first operate the robot, and while visually checking the operating state, correct the movement speed by adding or subtracting the correction value from the movement speed corrector to the already taught speed. It is possible to issue a teaching command only when the moving speed becomes appropriate after correction, and rewrite the speed information to the corrected information.

Therefore, according to the present application, since corrections can be made while actually moving the robot, corrections can be made with great accuracy and ease of operation, and the previous information is not erased but is The present invention has an excellent feature in that learning-like teaching can be performed by accumulating correction values, so corrections can be made easily and failures can be reduced.

[Brief explanation of the drawing]

FIG. 1 is an electrical block diagram of an embodiment according to the present invention. FIG. 2 is an explanatory diagram for explaining welding points. Figure 3 is a composite vector diagram. FIGS. 4-1 and 4-2 are explanatory diagrams for explaining the adjustment section. 1... Memory circuit, 2, 3.4... Position sensor, 5.6.7... Digital subtraction circuit 8
, 9 , 10°17...D/A converter, 11
...Movement speed modifier, 12.13...
Contact piece, 14...Speed correction amount setting device, 15...
...A/D converter, 16...Digital adder, 18...Exponential function generator, 19...
・Moving speed calculation circuit, 20... Control circuit, 10
0...Current position sensor, 101...Subtraction circuit, 102...Speed correction circuit.

Claims (1)

[Claims] 1. When correcting the movement speed of a robot whose movement trajectory is set by passing through a finite number of discretely set passing points in a predetermined order, the memory circuit is The robot is operated under preset speed conditions, and the robot moves while correcting the movement speed within the movement section determined by the passing points by adding or subtracting the value issued from the movement speed modifier. After confirming that the moving speed has been corrected to an appropriate value, a command to rewrite the speed condition is issued to the memory circuit, and this rewrite command and a NEXT signal for reading the next information from the memory circuit are issued. A method for correcting a moving speed of a robot, characterized in that, when a match is found, the moving speed in the memory circuit is rewritten to a corrected value based on this correction. 2. A memory circuit 1 in which stored information can be rewritten, a current position sensor 100 that detects the current position of the robot, and information regarding the robot's route position preset in the memory circuit 1 and the current position sensor 100. a subtraction circuit 101 that calculates the residual difference from the detected value; and a speed correction circuit 102 that reads out speed information preset in the storage circuit and adds or subtracts a correction value from the speed corrector 11 to this information.
Then, the information rewrite command WRITE is sent from the movement speed calculation circuit 19 which calculates the movement speed of the robot in each axial direction and rotational direction based on the signals from the subtraction circuit 101 and the speed correction circuit 102, and the movement speed corrector 11. When the NEXT signal is input and the next information is read from the moving speed calculation circuit 19, a horizontal signal is input from the control circuit for rewriting the old speed information in the storage circuit 1 to the corrected breaking speed information. A moving speed correction device for a robot, characterized in that: