JPH056217A - Method for controlling industrial robot - Google Patents

Abstract

PURPOSE:To improve working efficiency to the many kinds of works by numeralizing working shape data and working data such as working conditions, etc., inputting those data and successively calculate points to be the orbit of a robot. CONSTITUTION:Based on the working data inputted in an input process SP 2, point data are calculated for moving the robot to a prescribed position and based on these point data, prescribed work is executed. After this work process SP 7 is completed, it is discriminated in a process SP 8 whether all the prescribed works are completed based on the working data or not and when they are not completed, the robot is controlled by feedback processes (SP 9 and 10) to calculate the next point data by returning it to a preceding calculation process (SP 6). Thus, since the data such as the shape of the work or the working conditions are made numerical and inputted, one or plural point data constituting the orbit of the robot can be calculated and are prepared at real time, and it is not necessary to execute teaching in advance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial robot employing a teaching / playback system for an industrial robot, and more particularly to a control method capable of reducing teaching work.

[0002]

2. Description of the Related Art Conventionally, when teaching an industrial robot of this type, an operator is in front of the industrial robot and directly inputs point data by performing remote operation or the like. Specifically, a worker designates the position of the industrial robot for each point, and creates a work trajectory as point data by changing these points with time.

[0003]

By the way, in the teaching work of the industrial robot, a great amount of work time is required because the robot is actually positioned at all points of the work locus. . Further, at this time, if part of the point data is defective, re-teaching, correction of the point position, correction of speed, etc. are required, and the correction work also requires a great deal of time.

The present invention has been made in view of the above circumstances, and enables a robot to efficiently perform work such as painting on various kinds of works having different shapes and working conditions. An object of the present invention is to provide a control method for an industrial robot that can significantly improve its work efficiency.

[0005]

In order to achieve the above object, in the first invention, an input step for inputting work data, and the robot is set to a predetermined position based on the work data input in the input step. A calculation process for calculating one or a plurality of point data for movement, and a work process for moving the robot to a predetermined position and performing a predetermined work based on the one or a plurality of point data calculated in the calculation process. Then, after the work process is completed, it is determined whether or not all the work by the robot is completed based on the work data input in the input process. If the work is not completed, the process is returned to the calculation process and the next one or The industrial robot is controlled by a feedback process of calculating a plurality of point data.

The second aspect of the invention is characterized in that the work data is the shape data of the work.

The third invention is characterized in that the work data is used as the work condition.

[0008]

According to these inventions, one or a plurality of point data constituting a trajectory of a robot can be calculated in real time by digitizing and inputting work data such as work shape data and work conditions. You can As a result, it is possible to easily handle a wide variety of workpieces having different shapes, working conditions, etc., simply by changing the work data input in the input process without actually performing the teaching work using a robot in advance.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

First, reference numeral 100 in FIG. 1 is a teaching / playback type or articulated type robot main body 2 for painting a work W conveyed while being suspended from a conveyor 1. It is a painting robot system having.

The articulated robot 2 used in the coating robot system 100 as described above.
Is a base 3 placed on the floor surface, an arm support 4 provided on the base 3 and rotatable about a vertical axis (a), and a horizontal axis (robot) on the arm support 4. ), A first arm 5 rotatably provided, a second arm 6 rotatably provided at the tip of the first arm 4 about a horizontal axis (c), and this second arm. 6, a wrist mechanism 7 provided at the tip of the wrist 6 and a working device such as an application gun 8 attached to the tip of the wrist mechanism 7.

In the robot body 2, the arm support 4, the first arm 5, the second arm 6, and the wrist mechanism 7 are connected to the axes (a) to (a) by a driving mechanism such as a servo motor provided at various places. C) and the like are rotated relative to each other, so that the coating gun 8 located at the tip of the workpiece is positioned in an arbitrary space (point) around the work.
In this case, in the robot body 2, the base end portion of the arm support portion 4 is set as the origin 0 of the XYZ coordinates, and the tip end position of the wrist mechanism 7 is represented by point data indicated by P (x, y, z). I am trying.

The coating robot system 100 will be described below.
In Fig. 4, the work W is formed in a short flat plate shape, and the robot main body 2 has a constant coating path as shown in Fig. 4 with respect to the work W formed in a rectangular flat plate shape. The control methods (1) to (4) in the case where the coating work is performed at a constant speed with a width (width of the coating locus) will be described with reference to FIGS. 2 to 5.

(1) First, the shape data a, b, h of the work W described below are numerically input (see FIGS. 2 to 3). (A) The vertical dimension of the work W is a millimeter. (B) The horizontal dimension of the work W is b mm. (C) The height of the upper end of the work W is h mm. The upper end height h means the distance from the origin 0 of the XYZ coordinate system to the upper end of the work W, as shown in FIG. In addition, these data a, b, h are the work W in advance.
A numerical value may be registered for each, or a shape may be automatically recognized using an optical sensor such as a photoelectric tube, and the data obtained by this recognition may be digitized and input.

(2) Next, the following coating conditions p, w, g, v
Is numerically input (see FIGS. 2 and 4 to 5). (D) The distance from the coated surface of the work W to the tip of the coating gun 8 is p mm. (E) The width of the painting path (width of the painting locus) is w mm. (F) The coating path protrusion distance (distance of the coating trajectory protruding from the work W) is g mm. (G) The coating speed is v mm / sec.

(3) Next, the positional relationship of the conveyor 1, the robot body 2, the work position detector 9 (described later), etc.
Numerically input s, u, α (see FIG. 2). (H) Robot base position of robot body 2 (origin 0)
The distance from to the coated surface of the work W is s mm. (I) The distance from the work position detector 9 to the robot base position (origin 0) is u mm. (E) The pulse rate of the conveyor pulse transmitter (not shown) is α mm / pulse. The pulse rate of the conveyor pulse transmitter is set in advance how long (in millimeters) the work W is conveyed by the conveyor 1 each time one pulse is output from the conveyor oscillator. Is.

(4) Based on the numerical values input in the above (1), (2) and (3), the robot work is performed in accordance with the following procedure for each transfer cycle of the work W. Note that this work is performed for each step (SP) according to the flowchart stored in the storage unit of the control panel (not shown) shown in FIG.

<Step 1>: Start.

<Step 2>: The shape data a, b, h of the workpiece W, the coating conditions p, w, g, v, the positional relationship s, u, α of the robot body 2 are input.

<Step 3>: When the workpiece W is detected by the workpiece position detector 9, it is assumed that the workpiece standby position (work start position by the robot body 2) has been reached, and the robot body 2 at the workpiece standby position detects the workpiece W. Painting start point for work W: P ₀ (x ₀ , y ₀ , z ₀ ).
Is calculated by the following calculation formulas (1) to (8). The position of the work W detected by the work position detector 9 is the central portion (position of b / 2) of the length b along the moving direction, and is conveyed from this position by the conveyor 1 described later. The moving distance r of the workpiece W to be calculated is calculated.

Assuming that the number of coating passes (the number of coating traverses the work W) is n, the number n of coating passes is given by the following equation (1).

N = a / w (remainder is rounded up) ... (1)

Assuming that the working distance of the robot body 2 (distance of the coating locus) is 1, this working distance 1 is given by the following equation (2). The working distance 1 is calculated with the painting start point P0 as the starting point.

[0024]   l = n (b + 2g) + w (n-1) (unit: millimeter) (2)

When the working time (painting time) of the robot body 2 is t, this working time t is given by the following equation (3). The working time t is the coating start point P
It is calculated starting from ₀ .

T = 1 / v (seconds) (3)

The frequency of the pulse output from the conveyor pulse generator (not shown) is z pulses / second, and the conveyor 1
Where c is the speed of C, the speed of the conveyor 1, that is, the moving speed c of the work W conveyed by the conveyor 1 is expressed by the following equation (4). When the conveyor moving distance within the working time t is r, the conveyor moving distance, that is, the moving distance r of the work W conveyed by the conveyor 1 is expressed by the following equation (5).

C = αz (mm / sec) (4) r = ct (millimeters) (5)

From the above equations (1) to (5), the coating start point by the robot body 2 when the work W reaches the work standby position, which is the position where the work W is detected by the work position detector 9: Each component x of P ₀ (x ₀ , y ₀ , z ₀ )
_{When 0} , y ₀ , and z ₀ are obtained, the following (6) to (8) are obtained.

X ₀ = b / 2 + g−r / 2 (6) y ₀ = s−p (7) z ₀ = h−w / 2 (8)

<Step 4>: The robot body 2 is actually moved and positioned with respect to the coating start point P ₀ calculated in step 3.

<Step 5>: If the robot body 2 has moved to the coating start point P ₀ , the work W is detected by the work position detector 9 based on the output pulse of the conveyor pulse transmitter. It is determined whether or not the paintable position has been moved by a distance of d millimeters from the position, and if YES, the process proceeds to the next step 6. Here, whether or not the work W has been applied to the coatable position, that is, whether or not the work W has reached the coatable position that is advanced d (millimeters) from the work detection position P ₀ is determined as follows. First,
The distance d is expressed by the following equation (9).

[0033] d = u + b / 2-r / 2 (millimeters) (9)

When this distance d is converted to the number of conveyor pulses and is f, f is expressed by f = d / α (pulse). Then, this value f is set in the counter when the work W reaches the work detection position P ₀ , and this counter is set to 1 each time one pulse is output from the work pulse transmitter.
It is assumed that the work W arrives at the coatable position when the counter is reduced to 0. Note that this step 5 is a process in the case where the robot main body 2 moves to the stroke end, for example, and the coating start point P ₀ cannot be approached any more. By moving the work W by the distance d, It is intended to position the coating gun 8 of the main body 2 at the coating start point P ₀ .

<Step 6>: The next point, P1
Calculate the coordinates of. This point P1 is the end point of the first coating pass as shown in FIG. 4, and is (x ₁ , y ₁ , z
It is represented by ₁ ). As a specific calculation, the painting start point: P ₀ (x ₀ , y ₀ , z ₀ ) is obtained by orthogonal shift conversion. Here, only the x component is displaced when moving from the point P ₀ to P ₁ , but at the same time, the work W is also displaced by the conveyor 1 in the x component direction. Considering the point P ₁ (x ₁ , y
₁ , z ₁ ) is determined. That is, each component x ₁ , y ₁ , z ₁ of the point P ₁ is expressed by the following equations (10) to (12).

X ₁ = x ₀ − (b + 2g) (1-c / v) (10) y ₁ = y ₀ (11) z ₁ = z ₀ (12)

<Step 7>: The point P ₁ (x ₁ ,
When each component of y ₁ and z ₁ ) is obtained by calculation, a paint spray signal for causing the coating gun 8 of the robot body 2 to perform coating is output, whereby the coating gun 8 is applied to the work W. The robot main body 2 is moved from the coating start point P ₀ to the next point P ₁ at a coating speed v while spraying toward it.

<Step 8>: When the movement of the robot body 2 to the point P ₁ is completed, the output of the spray signal is stopped and the coating is stopped. Then, at this time, the count value of the coating pass number n set in step 2 is reduced by -1, and when the coating pass number becomes 0 as a result of further reduction, the process proceeds to step 11 and is not 0. In this case, the process proceeds to step 9, and in step 9, the point P ₂ (x ₂ , y ₂ , z ₂ ) which is the starting point of the next painting pass is calculated.

<Step 9>: The next point P ₂
Calculate the coordinates of. This point P ₂ is the starting point of the second coating pass as shown in FIG. 4, and (x ₂ ,
It is represented by y ₂ , z ₂ ). Note that here, as described in step 6, when the point P ₁ is moved to P ₂ , x
The component and the z component are displaced, but at the same time, the work W is also displaced in the x component direction by the conveyor 1, and in particular, the x component is determined in consideration of these displacements. That is, each component x ₂ points P _2, y _2, z ₂
Is expressed by the following equations (13) to (15).

X ₂ = x ₁ + w · c / v (13) y ₂ = y ₁ (14) z ₂ = z ₂ -w (15)

Then, the point P ₂ (x ₂ , y ₂ ,
After calculating z ₂ ), the robot main body 2 is moved from the point P ₁ to the point P ₂ in a state where the coating work on the work W by the coating gun 8 is stopped, and then the process returns to the previous step 6 and further. Then, a calculation for moving the robot body 2 from the point P ₂ which is the starting point of the second painting pass to the point P ₃ which is the ending point of the second painting pass is performed (step 6), and based on this calculation result , Robot body 2 while painting work W with painting gun 8
Is moved to point P ₃ (step 7). Then, in the next step 8, the coating work is stopped on the work W by the coating gun 8 as described above, and the number of coating passes n
The count value of is further reduced by -1 (that is, the coating pass number n is decremented each time the process proceeds to step 8), and if the result is that the coating pass number becomes 0, the process proceeds to step 11. Further, if not 0, the process proceeds to step 9, from the point P _3, performs component calculation for moving to a point P ₄ is the starting point of the paint path 3 knots.

The point P ₃ (x ₃ , y ₃ ,
Each component of _{z 3) x 3, y 3} , z 3 are represented by the following (sixteen) - (eighteen) formula, further, point P ₄ (x _4,
y _4, z ₄ each component x ₄ in), y _4, z ₄ the following (nineteen) -
It is expressed as in (21).

X ₃ = x ₂ + (b + 2g) (1 + c / v) (16) y ₃ = y ₂ (17) z ₃ = z ₂ (18)

X ₄ = x ₃ + w · c / v (19) y ₄ = y ₃ (20) z ₄ = z ₃ -w (21)

<Step 11>: When the count value of the coating pass shown in Step 8 becomes 0, it is determined that the coating work is completed, and a predetermined point is started from the final point (point P _{9 in} FIGS. 4 to 5). Move to the standby position Pg and wait 1
The cycle ends. At this time, the painting work on the work W by the painting gun 8 is stopped.
The coordinates of the standby position Pg may be calculated and stored in advance.

In this embodiment, although the example has a relatively simple shape and operation, the idea can be similarly applied to work on a more complicated work W. Also, in this example, points are calculated in real time, but in advance
The point data created by the above calculation may be input as a teaching program, and this teaching program may be utilized when a work W having the same shape and coating conditions is conveyed.

In the above flow chart, step 1 is the input step, and step 3, step 6,
Step 9 is a calculation process, and Step 7 and Step 1
0 is a work process, and step 8 is a feedback process. Further, in the calculation of step 3, step 6, and step 9, for example, when the coordinates of the next point (P ₁ ) are obtained, if the points are apart to some extent,
A plurality of point data for interpolating between the points are calculated. That is, in the calculation step, one or a plurality of point data are calculated.

[0048]

As described above in detail, according to these inventions, the points forming the trajectory of the robot can be determined by digitizing and inputting work data such as the work shape data and work conditions. It is possible to create calculations in real time. As a result, it is possible to easily handle a wide variety of workpieces having different shapes, working conditions, etc. simply by changing the work data input in the input process without actually performing the teaching work using a robot. The effect that the work suitable for the work can be efficiently performed by using the robot is obtained.

Further, at this time, if the shape data of the work is inputted by the sensor arranged in the work conveying path of the conveyor, the work of inputting the work data can be saved and the work efficiency can be improved. An effect that further improvement can be achieved is obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a painting robot system including a robot.

FIG. 2 is a plan view of the robot and the work W as seen from above.

FIG. 3 is a side view of FIG. 2 viewed from the side (X) direction.

FIG. 4 is a diagram showing a coating trajectory of a robot on a work W.

FIG. 5 is a view corresponding to FIG. 4, and shows an actual coating trajectory when the work W moves (a coating speed and a conveyor speed ratio 1
FIG.

FIG. 6 is a flowchart for executing a control method for an industrial robot.

[Explanation of symbols]

2 Robot body (robot) W Work P _{0 to} P ₉ points (point data)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location G05B 19/403 L 9064-3H C 9064-3H

Claims (3)

[Claims] 1. An input step of inputting work data, and a calculation step of calculating one or more point data for moving the robot to a predetermined position based on the work data input in the input step. A work process in which the robot is moved to a predetermined position to perform a predetermined work based on the one or more point data obtained in the calculation process; and work data input in the input process after the work process is completed. Based on this, it is determined whether or not all the work by the robot is completed, and if it is not completed, a feedback step of returning to the calculation step and calculating the next one or a plurality of point data, the industrial robot control method. . 2. The method for controlling an industrial robot according to claim 1, wherein the work data is work shape data. 3. The method of controlling an industrial robot according to claim 1, wherein the work data is a work condition.