JPS6057379B2 - Arm motion memorization method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an arm motion memorization method using a memorization and replay type arm operating device, such as a paint sprayer equipped with a paint gun.

Conventionally, when a memory regeneration type automatic painting machine (also called a painting robot) memorizes the painting path of the painting arm on the object to be painted, the operator puts the control system in a memorized state, holds the teaching arm, and attaches the painting gun to the tip of the robot. Install it and do the actual painting work.

At this time, the control system oscillates pulses at equal time intervals using, for example, a clock pulse oscillator built into the control system.
During pulse oscillation, each point on the coating trajectory is memorized, and during regeneration, each memorized point is replayed at the same time interval as during teaching, thereby automatically performing the same work as during teaching. During playback, the painting arm moves by linearly interpolating the deviation between the stored points, and its speed is proportional to the distance between the points. This is the CP method (Conti-n
This is called teaching using the uousPath method. deer·
This method had the following problems. (1) Since the painting work is carried out continuously from the beginning, if a mistake is made even once, it cannot be corrected.

It is necessary to start teaching again from the beginning, and partial corrections cannot be made. (2) During teaching, it is necessary to hold the arm and move it fairly quickly, at the same speed as in actual painting work.
Although the weight and other aspects of the arm are balanced, it is difficult to carry out fine-grained teaching because the arm is carrying something with a mass of about 9 in 20.

(3) When painting workpieces that are flowing on a conveyor line, it should be possible to paint the parts successfully by teaching painting the parts as they are, aligning the starting points, and regenerating them, but the conveyor speed fluctuates, making it a long process. The positions will gradually differ.

(4) Even if the workpiece has a flat shape, the number of axes the control system has, for example, if it is five axes, all five axes are required, making it difficult to reduce costs.

The present invention was proposed with the aim of eliminating these drawbacks. During playback, the arm moves by linearly interpolating the deviation between the memorized points, and its speed is determined by the distance between the points. In an arm motion memorization method using a memory/regeneration type arm operating device equipped with a control system that generates a speed proportional to ΔS so that it becomes the desired playback speed.
To provide an arm motion memorizing method characterized in that the arm position is memorized point by point.

In this case, in the case of a straight line, each point to be stored is automatically calculated and stored by the computer by recording two points at both ends and recording the playback speed. Furthermore, if the two points at both ends and the playback speed are recorded, the computer calculates the data online (during the playback operation) during playback. The method of the present invention has the following features. (1) Instead of storing each point on the arm path at equal time intervals, that is, subject to time constraints, as in the past, the movement speed of the arm during playback is determined by the distance ΔS between points. Since the time is determined, the teacher can slowly create one point at a time without worrying about the speed of playback, so anyone can teach easily and systematically without wasting time.

(2) Since the data is memorized one point at a time, the playback progresses one point at a time.

Therefore, if you want to correct the trajectory only at a specific part in the middle, play it one point at a time and advance the arm to the point you want to correct.
Partial correction can be performed by re-teaching only the part to be partially corrected from that position. (3) Conventionally, for example, the control panel of a painting robot has multiple feedback systems, for example, 6 axes, installed in parallel, and when a worker attaches a paint gun to the end of the arm and moves it, all 6 axes operate and one person This CP method of teaching is possible because all six axes can be memorized by an operator.

If the PTP method (POintTOPOint method) storage method can be adopted, a plurality of arms can be controlled with one control panel. In the conventional method where a person moves the teaching arm, the trajectory is memorized at 13 points at equal time intervals, and then replayed at the same time interval, the gun movement speed during teaching must be the same as during actual painting. Therefore, under these conditions, it is difficult to operate multiple guns at the same time to synchronize the timing, or to adjust the best timing at the same time.
Routing is extremely difficult. On the other hand, in the method of the present invention, the teaching time is unrelated to the regeneration operation time, so it is possible to spend as much time teaching one point at a time, and even when teaching multiple guns at the same time. , only one operator can aim and accurately teach each gun. Therefore, one control panel can control a plurality of guns with a small number of axes, up to the number of axes that the control panel can control. For example, if the control panel is for 5 axes, it can control two 2-axis machines and one 1-axis machine at the same time. Next, examples of the method of the present invention will be described.
FIGS. 1 and 2 show a method of painting an object to be coated using a memory and replay type painting machine. 1 in Figures 1 and 2
is an electric control panel, and 2 is a hydraulic power unit.

In this embodiment, the electric control panel 1 has a control system that controls five axes simultaneously, and this feature uses a highly reliable wire memory that operates purely electrically as a storage medium, and the paint gun With a trajectory as a collection of points, the position of each point can be stored and reproduced. The arm body has an intrinsically safe explosion-proof structure, and is therefore entirely driven by hydraulic pressure, and the hydraulic power unit 2 is the hydraulic power source for this purpose.

3 is the main body of the paint sprayer, which has five axes of freedom.

Reference numeral 4 denotes a hanger conveyor that moves in the direction of the arrow; 5 the object to be coated that is suspended on the hanger conveyor 4 and transferred; 6 a gear meshed with the conveyor 4; 7 driven by the gear 6; An incremental type pulse oscillator 8 for detecting speed is attached to the coating machine body 3 and is a coating arm equipped with a coating gun at the tip.

To explain the teaching method of the painting gun of the painting machine 3 shown in Figs. 1 and 2, switch the control panel 1 to teaching mode, aim the painting gun perpendicularly to the painting surface of the object to be painted 5, and aim at A or B.
, C, . . . and memorize them one by one.

The speed is not particularly memorized, and a certain time Δt is set between each point during playback.
advances the memory address (point position is commanded every Δt time). Therefore, if the point-to-point distance is ΔS, the point-to-point velocity V
= ΔS/Δt, and since Δt is constant, the speed is ΔS
is proportional to. In other words, the longer the distance between the points at the time of memorization, the faster the speed will be reproduced. Specifically, Δt~0.1~0.2
seconds, and the coating speed is V=0.5 to 1.0Tr1,/SeC, so Δt=0. Hoe, painting speed V=1.0m/S
ec, ΔS will be stored at intervals of about 2001rn. In addition to the above, in the beating system using a microcomputer, if the line from A to H in Figure 1 is a straight line, only points A and H are memorized, and when the desired playback speed is set, the B-G point along the way is stored. The points up to this point are automatically calculated by the microcopy computer and automatically stored. Also, the points B-G are not calculated and stored in memory when they are stored, but are calculated (online) by the microcopy computer during playback from the distance between points A and H and the playback speed. Sometimes you can make it work. At this time, if the object 5 to be coated is stationary, it may be left as is, but if the object 5 to be coated is flowing continuously on the conveyor 4, point A, point B, etc.
Each time a point is memorized, it is necessary to move the object 5 to be coated by the amount that the conveyor 4 moves in Δt seconds.

Therefore, each time one point is memorized, the arm 8 is manually moved to a predetermined position taking into account the amount of movement by the conveyor 4. With control using a microcomputer, even if the object to be coated 5 is stored in a stopped state using the PTP method, the amount of movement of the object to be coated in Δt seconds is calculated, and from point A to point B to point C, etc. As the information is stored in sequence, the relative position between the object to be coated and the spray gun is automatically memorized so that it does not change even when the object to be coated moves or during continuous playback. The speed of the conveyor 4 is detected by the pulses of the pulse oscillator 7, converted into an increase or decrease in the number of pulses, and this signal is introduced into the control panel 1, and the operating speed of the main body 3 is changed in proportion to the high or low of this pulse frequency. I can do it.

In this case, as the speed of the conveyor 4 increases, the pulse frequency of the pulse oscillator 7 increases, and as the speed of the conveyor 4 decreases, the pulse frequency of the pulse oscillator 7 decreases.

As a result, the operation of the main body 3 increases or decreases in accordance with the increase or decrease in the speed of the conveyor 4. The method of reproducing the memorized point positions is to automatically advance and reproduce the address by Δt seconds per point.

A clock pulse for generating Δt seconds is generated based on the pulse oscillator 7. Therefore, when the conveyor 4 moves, the coating operation is automatically performed in proportion to its speed. Linear interpolation is used between points, so the bus does not get distorted, and it moves at a constant speed between points, so even if ΔS is quite long, the trajectory and speed will not vary and the finish of the painting will be maintained. There is no unevenness.

In short, when storing data, it is not stored using a signal from a pulse oscillator that oscillates pulses at equal time intervals, but is stored one point at a time by an external signal, such as pressing a memory button. Time can be automatically reproduced at equal time intervals (Δt) by the pulse oscillator that oscillates pulses at equal time intervals, or by the pulse oscillator 7 that follows the conveyor. FIGS. 3 and 4 show an embodiment in which the use of the method of the present invention makes it possible to replay the memories of a plurality of coating machines using one control panel.

In the figure, 1 is an electric control panel for controlling a 5-axis machine similar to those in Figures 1 and 2, 3a to 3c are single-axis paint machines with only the Z-axis, and 3d is a two-axis paint machine with Z-axis and β-axis. , and other symbols indicate the same type of equipment as those in FIGS. 1 and 2.

The object to be coated 5 is initially sent in state A by the conveyor 4.

After being painted by the coating machines 3a and 3b, next P
It is rotated by 90a at point B and is painted by coating machines 3c and 3d. The total number of axes of paint machines 3a to 3d is 1+1
+1+2=5 axes, one control panel 1 that can control 5 axes
The operation of these paint machines can be controlled independently.

Linear guide machines such as these one- and two-axis machines are used for painting the exterior surfaces of boxes, etc., where the objects to be coated are relatively simple. That is, the teaching method first uses a teaching box in which a pulse generator that can independently move each axis is placed in parallel with each axis, so that each axis can be moved independently by simply turning a knob, for example. In this state, in the same manner as in the case of Figs. 1 and 2, aim the coating guns of each of the coating machines 3a to 3d toward the object 5 to be coated, and simultaneously move each axis to one point such as A, B, ・C, etc. Memorize one by one. Since any position of each painting gun of each painting machine 3a to 3d is stored at the same time, the aiming positions of all four arms are stored together. When the object to be coated 5 is continuously conveyed by the conveyor 4, as in the case of the five-axis machine shown in Figs. The object 5 to be coated is moved to.

The reproduction method is exactly the same as in the case of FIGS. 1 and 2. By implementing the method of the present invention in this manner, there are the following advantages. (1) Since memorization is carried out slowly one by one without being restricted by time, anyone can teach painting work according to a plan, even if one is not an expert in painting.

(2) A single control panel can move multiple painting guns up to the number of axes that can be controlled by that control panel.

Therefore, for example, if a paint sprayer has two axes, if you use a six-axis control panel, four axes will be idle, but this can be used for another paint sprayer, so the cost will be reduced accordingly. can be reduced. (3) Even with a single-axis machine, the spray range and timing can be adjusted freely to accommodate changes in the object to be coated. (4
) points, so you can later retrieve each point one by one and partially modify the position of that point.

Further, when the object to be coated is sent by a conveyor, the operating speed of the coating arm 8 of the main body 3 can be changed in synchronization with the conveyor speed.

Since the conveyor speed and the operation of the coating arm are synchronized with each pulse of the pulse oscillator 7, there are the following advantages.
(1) If the conveyor line starts or stops midway,
Even if the conveyor line has inertia and flow, or even if there is a difference in startup characteristics between the conveyor and the sprayer, synchronization will not occur. (Ii) Even if the speed of the conveyor line changes during operation, the movement of the arm changes according to the speed of the line, allowing completely synchronous movement.

As described in detail above, the method of the present invention relates to a convenient method for memorizing arm motions using a memory-reproducing arm operating device. When objects are transferred by a conveyor, etc., the arms can always synchronize with the movement even if the conveyor's transfer speed changes, and a single control system can operate multiple arms at the same time, which is a very useful advantage.

Further, the scope of application of the method of the present invention is not limited to painting, etc., but can be applied to a wide range of applications, such as equipment for welding and sealing work, for example.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the case where the method of the present invention is applied to a 5-axis paint sprayer for teaching, Figure 2 is an explanatory diagram of Figure 1 seen from above, and Figure 3 is an explanatory diagram showing the case where the method of the present invention is applied to a 5-axis paint sprayer. An explanatory diagram showing the case where teaching is applied to a shaft and two-shaft paint sprayer,
FIG. 4 is an explanatory diagram of FIG. 3 viewed from above. 1... Electric control panel, 2... Hydraulic power unit, 3, 3a, 3b, 3c, 3d... Painter main body, 4... Hanger conveyor, 5...
...Object to be painted, 6...Gear, 7...
Incremental pulse oscillator, 8...painting arm.

Claims (1)

[Claims] 1 Memory and replay type arm operation equipped with a control system in which the arm moves by linearly interpolating the deviation between the memorized points during replay, and the speed is proportional to the distance between the points. In the arm motion memorization method using a machine, where the distance between the points to be memorized is ΔS, and the time to advance the point command value during reproduction is Δt, the distance between the points Δ is set so that the arm reaches the desired reproduction speed.
An arm motion memorization method characterized by taking S and memorizing arm positions one by one in a point-to-point method.