JP2713656B2 - Synchronous conveyor data input method for industrial robots - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for inputting synchronous conveyor data of an industrial robot that works on a work conveyed by a conveyor or the like.

[Prior Art] In a robot that works on a workpiece conveyed by a conveyor or the like, teaching work is performed with the conveyor stopped, and the position data of the conveyor as well as the position data of the robot are stored as step data in the robot. In the regenerating operation, the position data of the robot is shifted along the conveyer and reproduced according to the difference between the position data of the conveyer in the step and the position data of the conveyer during reproduction.

FIG. 2 is a block diagram showing a configuration of a general industrial robot. In the figure, 1 is a robot body, 2 is a work, 3 is a conveyor for conveying the work 2, 4 is a work control panel, 5 is a conveyor drive motor, and 6 is an encoder that generates a pulse according to the rotation of the conveyor drive motor 5. .

A control device 8 is connected to the robot body 1. In the control device 8, reference numeral 9 denotes a reversible counter for detecting the position of the conveyor 3, which counts pulses generated by the encoder 6, and is reset by the sensor 7 for detecting the work 2. The sensor 7 is also used as a start signal of the robot during the regeneration operation. 10 is a central processing unit, 11 is a storage device, 12 is an operation panel, 13 is a calculation unit, 14 is a counter that obtains deviation of each axis of the robot or
The A / D converter 15 is an amplifier that supplies power to the motor according to the deviation.

At the time of teaching, the conveyor 3 is stopped at an arbitrary position to perform a teaching operation, and the value of the reversible counter 14 is stored as position data of the robot body 1 and the value of the reversible counter 9 is simultaneously stored as position data of the conveyor. To memorize. At the time of reproduction, the value of the reversible counter 9 at the time of reproduction is read, and the end effector attached to the tip of the robot body 1 is shifted along the conveyor 3 by the difference from the data at the position of the conveyor stored in the step. To play as. FIG. 3 shows this state.

Now, description will be made on the assumption that the conveyor 3 is inclined by an angle θ with respect to the x direction of the robot in the xy plane as shown in FIG. The position of the end effector of the robot at the time of teaching _{(x t, y t, z} t), p t the pulse value during the teaching of the encoder 6, the pulse value during reproduction p _p, the resolution of the encoder 6 Delta] p When (mm / pulse) to the position of the end effector at the time of reproduction _{(x p, y p, z} p) _{is, x p = x t + Δp} (p p -p t) cosθ y p = x t + Δp (p the _{p -p t) sinθ z p =} z t. That is, in order to obtain the shift amount along the movement of the conveyor, in addition to the teaching data of each step,. Resolution of encoder 6. Movement of conveyor 3. The traveling direction of the conveyor 3 is required as data. In the prior art, these are input numerically from the operation panel 12.

[Problems to be Solved by the Invention] In the above-mentioned conventional technology, (1) The inclination of the conveyor 3 has to rely on on-site measurement in consideration of an installation error or the like, and it is difficult to easily obtain an accurate value. On the other hand, the shift accuracy decreases due to the error of this value. In addition, when it is not simply an xy plane but is three-dimensionally inclined, it is almost impossible to measure.

(2) Since a speed reduction mechanism is interposed between the encoder 6, the motor 5, and the conveyor 3, the resolution of the conveyor 3 needs to be calculated more troublesomely for each individual conveyor than the speed reduction ratio. However, in general, it is rare to easily obtain these data, and it is not only necessary to carry out a physical survey but also to easily cause a trouble due to a calculation error or the like.

(3) It is necessary to input these data as parameters, and there are many parameters including parameters for other uses, and input and management are difficult.

And so on.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a synchronous conveyor data input method for an industrial robot capable of inputting synchronous conveyor data accurately and without any trouble.

[Means and Actions for Solving the Problems] The present invention is to store the position data of the robot when the robot points at the same point on the conveyor together with the position data of the conveyor before and after moving the conveyor in the traveling direction. The data on the robot coordinates of the data and the distance and the position data of the conveyor are obtained from the data on the conveyor, and the above data is always used when shifting the teaching data by storing it in a storage device. Can be absorbed up to the installation error without performing on-site measurement, and it is not necessary to investigate the reduction gear and transmission mechanism in advance to calculate the resolution of the encoder.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The present invention stores the position data of the conveyor 3 together with the position data of the robot body 1 at the time of teaching the industrial robot shown in FIG. In an industrial robot that reproduces a work at a position different from the teaching position by shifting the taught position data in the conveyor moving direction,
It uses the following synchronous conveyor data input method. In this case, in the present invention, the operation panel 12 includes a conveyor data operation switch (not shown).

FIG. 1 shows how points on the conveyor 3 are taught. In the figure, reference numeral 20 denotes a jig for teaching or an end effector to be substituted, point A is a point on the conveyor 3 stored first, and point A 'is a conveyor after moving the conveyor by an arbitrary amount in the traveling direction. Shows the same point as point A above.

The point A and the point A 'are taught by a storage switch (not shown) on the operation panel in the same manner as ordinary position data, and the position data is stored in the storage device 11. At this time, the address for storing the position data is specified on the operation panel to a predetermined value.

Next, by pressing a conveyor data operation switch (not shown) on the operation panel, the conveyor data is obtained in advance by the following procedure.

. The orthogonal coordinate values of points A and A 'are obtained.

Let the coordinates of point A on the conveyor taught first be (x ₁ , y ₁ ,
z ₁ ), the pulse value of the encoder 6 at that time is p ₁ , a point A where the conveyor is once moved in the traveling direction and moves together with the conveyor.
(X ₂ , y ₂ ,
z ₂ ), and let the pulse value of the encoder 6 at that time be p ₂ .

. Data related to the conveyor 3 is calculated and stored in the storage device 11.

The shift amount of the conveyor 3 in each of the x, y, and z directions per pulse is: Δx = (x ₂ −x ₁ ) / (p ₂ −p ₁ ) Δy = (y ₂ −y ₁ ) / (p ₂ −p ₁ ) Δz = (z ₂ −z ₁ ) / (p ₂ −p ₁ ). This value includes all the elements of the inclination and traveling direction of the conveyor 3 and the resolution of the encoder 6. Therefore,
It is possible to absorb the installation error without measuring the inclination of the conveyor 3 on site, and it is not necessary to investigate the reduction gear and the transmission mechanism in advance and calculate the resolution of the encoder.

When the data is reproduced in synchronization with the conveyor 3, the data stored in the storage device 11 is read out during the reproduction operation, and the following operation is performed to shift the position data. The position of the end effector 20 of the robot body 1 at the time of teaching is (x _t , y _t , z _t ), and the pulse value of the encoder 6 at the time of teaching is
p _t, when the pulse value p _p during playback, the position of the end effector 20 during playback _{(x p, y p, z} p) , the following equation _{x p = x t + Δx (} p p -p t) y determined by _{p = y t + Δy (p} p -p t) z p = z t + Δz (p p -p t), also the calculation is easy. The position data can be shifted as described above, and very high accuracy can be obtained.

[Effects of the Invention] As described above, according to the present invention, the inclination of the conveyor can be absorbed up to the installation error without performing on-site measurement, and the reduction gear and the transmission mechanism need to be investigated in advance to calculate the resolution of the encoder. There is no need to input and manage parameters. Further, even a three-dimensional inclination that is difficult to express as a parameter can be easily obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention, FIG. 2 is a block diagram showing a configuration of a conventional industrial robot, and FIG. 3 is an explanatory diagram of a position data shift of the robot in FIG. 1 ... Robot body, 2 ... Work, 3 ... Conveyor,
4 ... Motor control panel, 5 ... Motor, 6 ... Encoder, 7 ... Sensor, 8 ... Control device, 9 ... Reversible counter, 10 ... Central processing unit, 11 ... Storage device, 12 ... Operation panel, 13 ... Calculation unit, 14 ... Reversible counter or A / D
Converter, 15: D / A converter and amplifier, 20: End effector.

Claims (1)

(57) [Claims] When a work conveyed by a conveyor is taught, the position data of the conveyor is stored together with the position data of the robot at the time of teaching. In an industrial robot that shifts and reproduces, the conveyor is moved by an arbitrary amount in advance, and storage means for storing the same point on the conveyor before and after the movement and the position of the conveyor, and a taught position from the data stored in this means. A synchronous conveyor data input method for an industrial robot, comprising: arithmetic means for obtaining data such as a resolution of a conveyor position detector and a tilt and a traveling direction of the conveyor necessary for shifting data.