JPH09258813A - Industrial robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently execute instructed work even if an original working area which an industrial robot has is limited narrowly by providing a control means which corrects an orbits so as to be included in the working area in the case that the orbit goes over the working area to show the allowable range of movement. SOLUTION: The position ps of a painting gun at a middle point of moving time, i.e., at the time T/2 is determined from the moving time T and the positions p1, p2 and the moving speeds v1, v2 given as teaching data, and it is compared with the working area of a robot shown by a broken line. In the case that the position ps is the position to go over the working area, corrected moving time Ta is calculated for the working area from Ta=(1-K/L)T on the basis of the distance K of the going-over-working area of a transfer orbit and the turning back width L of the transfer orbit and the moving time T. Then, the transfer orbit after the adjustment of the moving time in which the posiiton ps does not go over the working area is obtained on the basis of the corrected moving time Ta.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial robot, and more particularly to a technique suitable for use in a teaching / playback type industrial robot.

[0002]

2. Description of the Related Art As is well known, there is a teaching / playback type painting robot as one type of industrial robot. Such a coating robot performs work (painting) on a work target (coating target) by moving a coating gun attached to the tip of a robot arm along a predetermined track (painting trajectory). is there. This type of painting robot creates and saves teaching data from the position of the representative point of the painting object input during teaching (teaching), and creates the painting trajectory based on the teaching data during playback (reproduction). To move the painting gun.

[0003]

By the way, the above-mentioned object to be coated is placed within the movement range of the coating gun originally possessed by the coating robot, and naturally the coating orbit is also within the movement range. However, depending on the installation environment (location) of the painting robot, the movement range may be limited to a narrower range.
In such a case, if the coating robot is operated along the coating trajectory generated based on the teaching data, the coating gun cannot be moved at the speed indicated by the teaching data. Further, conventionally, an operator actually confirms whether or not the coating trajectory is within the operation area of the coating robot in consideration of the above installation environment by actually reproducing the coating robot.

That is, as a result of the regenerating operation, when the painting trajectory is not within the operation area of the robot in consideration of the above installation environment, it is necessary to redo the teaching and correct the teaching data. However, there is a problem that the efficiency of is significantly reduced. In addition, it is difficult for a skilled worker to set the position of the object to be coated in consideration of the above-mentioned painting trajectory in a narrowly restricted operation area, and it takes a very long time to generate the final teaching data. There was also a problem that it required.

The present invention has been made in view of the above-mentioned problems, and has the following objects. (EN) Provided is an industrial robot which can efficiently perform a teaching work even when the original operation area of the industrial robot is limited. (EN) Provided is an industrial robot capable of suppressing re-teaching even if the original operation area of the industrial robot is limited.

[0006]

In order to achieve the above object, as a first means, a trajectory is generated based on prestored data, and the working means is moved along the trajectory to work an object. In an industrial robot that performs a predetermined work on, while generating the trajectory based on the data, storing an operation area indicating a permissible range of movement of the working means, and when the trajectory deviates from the operation area, Means comprising control means for modifying the trajectory to fit within the operating region are employed.

As second means, in the first means, the data is teaching data stored by teaching, and the teaching data is position data of a plurality of teaching points and moving speed data of working means at the teaching points. The means consisting of is adopted.

As a third means, in the second means, when it is detected that the transition trajectory indicating the turning back from one teaching point to the next teaching point deviates from the operation area, the position of each teaching point is detected. Means comprising a control means for modifying the transition trajectory to be within the operating region by correcting the data to move it into the operating region is employed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A teaching / playback type coating robot will be described below as an embodiment of an industrial robot according to the present invention with reference to the drawings.

FIG. 2 is a system configuration diagram of the coating robot in this embodiment. In this figure, reference numeral 1 is a robot arm, which is a first arm 1a rotatably fixed in a vertical plane with respect to a wall A provided vertically,
A second arm 1b rotatably attached to the first arm 1a in a horizontal plane, a wrist portion 1c also rotatably attached to the second arm 1b in a horizontal plane, and the wrist portion. It is composed of a coating gun 1d (working means, coating means) rotatably provided in a plane vertical to 1c. The robot arm 1 is to be installed in a painting workshop, and a coating object (working object) C placed on a workbench B is provided within the operating range of the robot arm 1.

Further, each joint portion of the robot arm 1, that is, the connecting portion between the wall and the first arm 1a, the first arm 1a.
And a second arm 1b, a connection portion between the second arm 1b and the wrist portion 1c, and a connection portion between the wrist portion 1c and the coating gun 1d are provided with motors for operating these joint portions. Each of these motors is provided with an encoder that detects the rotation speed and rotation position of the motor.

Reference numeral 2 is a controller (control means) for controlling the movement of the robot arm 1, and the movement of the robot arm 1 is controlled by controlling the servo motors using the detection signals output from the encoders as feedback information. Control. The detailed configuration of the controller 2 will be described later. Reference numeral 3 is a hand operation panel for inputting various instruction information to the controller 2 for operating the robot arm 1.

It should be noted that the controller 2 is generally installed at a place distant from the painting workshop where the robot arm 1 is installed. However, the hand-held operation panel 3 is provided in the painting work place, and for example, the painting robot is remotely moved at the time of teaching (teaching), or the painting target C
Used to enter the position of the representative point of.

Next, FIG. 3 is a block diagram showing the electrical construction of the coating robot. In this figure, the controller 2 comprises a CPU (central processing unit) 2a, a ROM (read only memory) 2b, a RAM (read / write memory) 2c and a motor driver 2d.
Further, reference numeral 4 is a motor, which is the first arm 1a described above.
The second arm 1b and the wrist portion 1c are operated.

The ROM 2b stores a control program for controlling the operation of the coating robot. The RAM 2c stores teaching data generated by the CPU 2a at the time of teaching and data relating to an operation area indicating a movable range of the coating gun 1d. For example, in the RAM 2c, teaching position data for a plurality of teaching points and the coating gun 1d at each teaching point are stored.
Teaching speed data indicating the moving speed of is stored as teaching data.

The CPU 2a includes the ROM 2b and RA
In order to generate the painting trajectory based on various information stored in the M2c and instruction information input from the operation panel 3 at hand, and to move the painting gun 1d along the teaching data, that is, the painting trajectory. 4 control information for each motor is generated.

The CPU 2a controls the motor driver 2d based on the teaching data and the operating position information of the motor 4 input from the motor driver 2d, and the control state of the coating robot and the like are provided on the hand operation panel 3. Display on the display device. The motor driver 2d is a CPU
Each motor 4 is directly driven based on the command information input from 2a and the operating position information input from each motor 4.

Next, with reference to FIG. 4, a method of generating a coating trajectory in the coating robot configured as described above will be described. In order to make the description easy to understand, the case of four teaching points 1 to 4 will be described.

First, based on the teaching data corresponding to the teaching points 1 to 4 previously taught, the linear trajectory 1 from the teaching point 1 to the teaching point 2 and the linear trajectory 2 from the teaching point 3 to the teaching point 4 are respectively Is generated. Then, transition trajectories that connect the teaching points 2 and 3 with a smooth curve are generated for the linear trajectory 1 and the linear trajectory 2 as follows.

Here, the end point of the linear trajectory 1 or the teaching point 2
Position p1, the moving speed v1 of the coating gun 1d when passing the position p1, the starting point of the linear trajectory 2, that is, the position p2 of the teaching point 3, and the moving speed v2 of the coating gun 1d when passing the position p2. Let p (t _k ) be a function that is given as data and indicates a transition trajectory connecting the positions p1 and p2.

Further, the moving time from the position p1 to the position p2 is T, and this moving time T is the sampling time Ts.
When the value divided by is a numerical value M and the variable k is an integer from 0 to a numerical value M, the variable t _k is given as a discrete value of t _k = k / M (1).

In such a case, the boundary condition of the function p (t _k ) at the starting point or position p1 and the ending point or position p2 of the transition trajectory is p (0) = p for the position of the starting point (t _k = 0). ₁ (2) For the speed at the start point, dp (0) / dt _k = v ₁ (3), and for the position at the end point (t _k = 1), p (1) = p ₂ (4) Is the following formula. dp (1) / dt _k = v ₂ (5)

Here, as the function p (t _k ) of the transition orbit satisfying the above boundary condition, there is a cubic polynomial of the variable t _k shown below. p (t _k ) = b ₀ + b ₁ · t _k + b ₂ · t _k ² + b ₃ · t _k ³ (6) Here, b _{0 to} b ₃ are coefficients.

Substituting the boundary condition expressions (2) to (5) into the cubic polynomial (6) to obtain the coefficients b _{0 to} b ₃ is expressed as follows. b ₀ = p ₁ (7) b ₁ = v ₁ · T (8) b ₂ = 3 (p ₂ −p ₁ ) − (2v ₁ + v ₂ ) / T (9) b ₃ = −2 (p ₂ − p ₁ )-(v ₁ + v ₂ ) / T (10)

Coating gun 1d in the transition orbit in this case
The acceleration of has the maximum value at the start point and the end point and is calculated by the following equation. d ² p (0) / d ² t _k = 6 (p ₂ −p ₁ ) / T ² −2 (2v ₁ + v ₂ ) / T (11) d ² p (1) / d ² t _k = −6 _{(p 2 -p 1) / T} 2 +2 (v 1 + 2v 2) / T (12)

Here, in the above equations (11) and (12), the moving time T is determined so that the maximum acceleration is equal to or less than the maximum acceleration allowed for the coating gun 1d. Then, the moving time T thus obtained and the equations (7) to (1
0) equation (function p (t _k indicating a transfer orbit indicated by 6)) based on is determined.

Next, referring to FIG. 1 and FIGS.
A method of correcting the transition trajectory when the transition trajectory thus generated deviates from the motion area of the robot will be sequentially described.

FIG. 5 is a plan view showing an operation area of the coating robot. The operating area of the coating gun 1d of the coating robot is limited to the range shown in the figure depending on the installation location and the like. For example, the operating area is X which the painting robot has.
-Position lower limit Xmin in the X-axis direction with respect to the Y coordinate system
From the lower limit position Ymin to the upper limit position Ymax in the Y-axis direction. Then, when the transition trajectory deviates from the operation region, the modified transition trajectory is generated as follows.

[First Modified Transition Trajectory Generation Method] FIG. 6
FIG. 7 is an explanatory diagram showing a method for generating a first modified transition trajectory. In this figure, the parameters according to the above-mentioned FIG. First, the moving time T, the positions p1 and p2 given as the teaching data, and the moving speed v described above.
By substituting 1, v2 into the above equations (7) to (10),
Each coefficient b0~b3 function indicating the transfer orbit p (t _k) is calculated. Then, an intermediate point of the moving time T, that is, time T /
The position ps of the coating gun 1d in 2 is obtained from the function p (t _k ) and compared with the robot motion area shown by the broken line in the figure.

When the position ps deviates from the operating region, the value of the moving time T is corrected (adjusted) as follows. That is, for the motion area, the corrected travel time Ta is calculated as follows based on the distance K at which the above-described transition trajectory exceeds the operation area, the turnback width L of the transition trajectory, and the travel time T. Ta = (1-K / L) ・ T (13)

That is, the moving time T is multiplied by a coefficient of 1 or less (the value in parentheses in the above equation) which is obtained according to the ratio of the distance K over the operation region and the turnback width L of the transition orbit. , A smaller value, that is, the correction movement time Ta. Then, based on the corrected moving time Ta, the transition trajectory after the moving time is adjusted so that the position ps does not exceed the operation area is obtained.

In this case, the position p
In order to give s a margin, the correction movement time Ta may be adjusted by the following equation. That is, the coefficient by which the moving time T is multiplied is further reduced by "0.1". Ta '= (1-K / L-0.1) * T (14)

Next, FIG. 1 is a flowchart detailing the procedure for the controller 2 to generate the coating trajectory. Hereinafter, each processing of the controller 2 will be described with reference to this flowchart. [Step S1] First, as teaching data stored in the RAM 2c during teaching, for example, teaching position data for N teaching points and teaching speed data corresponding to the teaching position data are read by the CPU 2a. The teaching position data and the teaching speed data are stored in association with the X-axis direction component and the Y-axis direction component of the XY coordinates of the coating robot, and the X-axis position table, the Y-axis position table, and the X-axis position table are stored. It is stored in the axis teaching speed table and the Y axis teaching speed table, respectively.

That is, in the X-axis teaching position table, N X-axis teaching positions Xi (i: integer from 0 to N-1).
However, in the Y-axis teaching position table, the Y-axis teaching position Yi
An X-axis teaching speed Xvi is stored in the axis teaching speed table, and a Y-axis teaching speed Yvi is stored in the Y-axis teaching speed table in association with an integer i.

[Step S2] A series of processing from steps S3 to S37 described below is repeated N times the number of teaching points, that is, by shifting the integer i from 0 to N-1.

[Step S3] X-axis teaching position Xi, X-axis teaching position Xi + 1, X-axis teaching speed Xvi, and X-axis teaching speed Xv
Based on i + 1, the X-axis teaching position Xi to the X-axis teaching position Xi +
The moving time (X-axis moving time) Tx of the coating gun 1d up to 1 in the X-axis direction is calculated.

[Step S4] Further, based on the Y-axis teaching position Yi, the Y-axis teaching position Yi + 1, the Y-axis teaching speed Yvi, and the Y-axis teaching speed Yvi + 1, the Y-axis teaching position Yi to the Y-axis teaching position is changed. The moving time (Y-axis moving time) Ty of the coating gun 1d in the Y-axis direction up to Yi + 1 is calculated.

[Step S5] X-axis movement time Tx and Y
The maximum value of the axis moving time Ty is the moving time T.

[Step S6] X-axis teaching position Xi, Xi + 1
Based on the X-axis teaching speeds Xvi and Xvi + 1, the moving time T, and the boundary condition expressions (2) to (5), the coefficients of the cubic interpolation formula of the transition trajectory in the X-axis direction, that is, the expression (6) are calculated. It is calculated.

[Step S7] Y-axis teaching position Yi, Yi + 1
Based on the Y-axis teaching speeds Yvi, Yvi + 1, the moving time T, and the boundary condition equations (2) to (5), the coefficients of the cubic interpolation equation of the transition trajectory in the Y-axis direction, that is, the equation (6) are calculated. It is calculated.

[Step S8] X of 1/2 of the moving time T, that is, the position of the midpoint of the transition trajectory (position ps described above)
The axial position is calculated and stored in the RAM 2c as the position X '.

[Step S9] Y of the half of the moving time T, that is, the position of the midpoint of the transition trajectory (position ps described above)
The axial position is calculated and stored in the RAM 2c as the position Y '.

[Step S10] It is determined whether or not the position X ′ exceeds the upper limit position Xmax in the X-axis direction of the operation area. Then, if this determination result is "YES", the process of step S11 is executed, and if the determination result is "NO", the process of step S15 is executed.

[Step S11] If the result of the determination is "YES", the absolute value of the difference between the position X'and the upper limit position Xmax is calculated and stored as the distance X "in the X-axis direction. It

[Step S12] Next, the X-axis teaching position X
It is determined whether i is larger than the X-axis teaching position Xi + 1.

[Step S13] As a result of the above determination, when (X-axis teaching position Xi> X-axis teaching position Xi + 1), the numerical value rx is calculated based on the following equation. rx = 1− | X ″ / (X′−Xi) | −0.1 (15) Here, the numerical value rx corresponds to the value in the X-axis direction of the numerical value in parentheses in the formula (14). Is.

[Step S14] On the other hand, the above step S12
In the case of (X-axis teaching position Xi.ltoreq.X-axis teaching position Xi + 1) as a result of the comparison, the numerical value rx is calculated based on the following equation. rx = 1− | X ″ / (X′−Xi + 1) | −0.1 (16) That is, of the X axis teaching position Xi and the X axis teaching position Xi + 1 by the processing of steps S12 to S14. The numerical value rx is calculated based on the larger value.

[Step S15] If it is determined in step S10 that the position X'does not exceed the upper limit position Xmax, then it is determined whether the position X'is smaller than the lower limit position Xmin in the X-axis direction of the operation region. Is judged.

[Step S16] The determination result is "YES".
In the case of, the absolute value of the difference between the lower limit position Xmin and the position X ′ is calculated as the distance X ″.

[Step S17] Similar to step S12, whether or not the X-axis teaching position Xi is larger than the X-axis teaching position Xi + 1 is compared and judged.

[Step S18] The result of this judgment is "YE
In the case of “S”, the numerical value rx is calculated based on the above equation (16).

[Step S19] On the other hand, when the determination in step S17 is "NO", the numerical value rx is calculated based on the above equation (15). That is, step S17-
By the processing of S19, the X-axis teaching position Xi and the X-axis teaching position Xi
The numerical value rx is calculated based on the smaller value of +1.

[Step S20] Above step S10-
Through a series of processes up to S19, the numerical value rx when the position X'on the transition trajectory deviates from the upper limit position Xmax or the lower limit position Xmin of the operation area in the X-axis direction was obtained. The value rx is fixed to "1" when the position X'is equal to or greater than the lower limit position Xmin, that is, when the position X'does not deviate from the operation area in the X-axis direction.

[Step S21] Subsequently, the numerical value ry is calculated in the Y-axis direction. The numerical value ry corresponds to the value in the Y-axis direction of the numerical value in the parentheses in the above formula (14). That is, it is determined whether or not the position Y ′ exceeds the upper limit position Ymax in the Y-axis direction of the operation region. If the result of this determination is “YES”, then the process of step S22 is executed, and if “NO”, In step S26, the process of step S26 is executed.

[Step S22] If the result of the determination is "YES", the absolute value of the difference between the position Y'and the upper limit position Ymax is calculated and stored in the RAM 2c as the distance Y "in the Y-axis direction. Is stored.

[Step S23] Next, the Y-axis teaching position Y
It is determined whether i is larger than the Y-axis teaching position Yi + 1.

[Step S24] As a result of the comparison, if (Y-axis teaching position Yi> Y-axis teaching position Yi + 1), the numerical value ry is calculated based on the following equation. ry = 1- | Y "/ (Y'-Yi) | -0.1 (17)

[Step S25] On the other hand, the above step S23
In the case of (Y-axis teaching position Yi ≤ Y-axis teaching position Yi + 1) as a result of the comparison in, the above numerical value ry is calculated based on the following equation. ry = 1− | Y ″ / (Y′−Yi + 1) | −0.1 (18) That is, of the Y axis teaching position Yi and the Y axis teaching position Yi + 1 by the processing of steps S23 to S25. The numerical value ry is calculated based on the larger value.

[Step S26] If it is determined in step S21 that the position Y'does not exceed the upper limit position Ymax, it is determined whether the position Y'is smaller than the lower limit position Ymin in the Y-axis direction of the operation region. Is judged.

[Step S27] The judgment result is "YES".
In the case of, the absolute value of the difference between the lower limit position Ymin and the position Y ′ is calculated as the distance Y ″.

[Step S28] Similar to step S23, whether or not the Y-axis teaching position Yi is larger than the Y-axis teaching position Yi + 1 is compared and judged.

[Step S29] This determination result is "YE
In the case of “S”, the numerical value ry is calculated based on the above equation (18).

[Step S30] On the other hand, when the determination in step S28 is "NO", the numerical value ry is calculated based on the above equation (17). That is, step S28-
By the processing of S30, the Y-axis teaching position Yi and the Y-axis teaching position Yi
The numerical value ry is calculated based on the smaller one of +1.

[Step S31] Above step S21-
Through a series of processes up to S30, the numerical value ry when the position Y'on the transition trajectory deviates from the upper limit position Ymax or the lower limit position Ymin of the operation area in the Y-axis direction was obtained. The value ry is fixed to "1" when the position Y'is not less than the lower limit position Ymin, that is, when the position Y'does not deviate from the operation area in the Y-axis direction.

[Step S32] The numerical value rx and the numerical value ry obtained by the above processing are compared, and the smaller value is taken as the numerical value r.

[Step S33] Then, the numerical value r is "1".
It is judged whether or not it is smaller than, and the result of this judgment is "YE
S ", that is, the position ps on the transition orbit (see FIG. 6 above)
Is outside the operating region in the X-axis direction or the Y-axis direction, the process of step S34 described below is executed.

[Step S34] Here, the moving time T is corrected using the numerical value r as described above. That is, by multiplying the travel time T by the numerical value r, the travel time T
A smaller value, that is, the corrected movement time Ta is calculated.

[Step S35] X-axis teaching position Xi, Xi + 1
And the X-axis teaching speeds Xvi, Xvi + 1 and the above correction movement time T
Based on a and the boundary condition expressions (2) to (5),
Each coefficient of the cubic interpolation formula of the transition trajectory in the X-axis direction is calculated.

[Step S36] Y-axis teaching position Yi, Yi + 1
And the Y-axis teaching speeds Yvi, Yvi + 1 and the above-mentioned correction movement time T
Based on a and boundary condition expressions (2) to (5), each coefficient of the cubic interpolation expression of the transition trajectory in the Y-axis direction is calculated.

[Step S37] Each coefficient is determined by the cubic interpolation formula calculated by the above processing to generate a transition trajectory.

[Second Modified Transition Trajectory Generation Method] FIG. 7
FIG. 7 is an explanatory diagram showing a method for generating a second modified transition trajectory. This method is to adjust the moving speed v1 at the starting point p1 and the moving speed v2 at the ending point p2 of the transition trajectory so that the position ps is within the operating range.

First, it is determined whether or not the position ps calculated based on the moving time T is within the operation region as in the case of the first modified transition trajectory generation method, and the position of the position ps corresponds to the operation region. If the deviation is out of the range, the moving speed v1 and the moving speed v2 are adjusted as follows so that the folding width L'is within the operation region indicated by the broken line.

That is, the position ps shown by the above equation (6) is shown as follows based on the above equations (7) to (10). _{p (1/2) = b 0 +} b 1/2 + b 2/4 + b 3/8 = p 1 + v 1 · T / 2 + {3 (p 2 -p 1) - (2v 1 + v 2) T} / 4 + _{{-2 (p 2 -p 1)} - (v 1 + v 2) T} (19)

[0074] Here, v1 = When v2, p (1/2) = p 1 + (p 2 -p 1) / 2-v 1 · T / 2 (20) The starting position ps transition trajectory p1 and 'obtained by adding, i.e. _{p (1/2) = (p 2} + p 1) / 2 + L' wrap width L to the arithmetic mean of the endpoint p2 when a (21), the corrected moving velocity at the starting point p1 in this case The corrected moving speed v2 'at v1' and the end point p2 is expressed as follows. v ₁ ′ = −2L ′ / T (22) v ₂ ′ = v ₁ ′ (23) Then, the corrected moving speeds v ₁ ′, v calculated in this way
2'is used to calculate the coefficients b0 to b3 of the equation (6) to obtain the transition orbit.

At this time, the time t1 required for decelerating the moving speed v1 to the corrected moving speed v1 'and the moving speed v
Time t required to accelerate 2 to the corrected moving speed v2 '
2 is calculated by the following formula. t ₁ = (v ₁ −v ₁ ′) / a _max (24) t ₂ = (v ₂ −v ₂ ′) / a _max (25) where a _max is the acceleration allowed for the movement of the coating gun 1d. It is the upper limit.

Further, the deceleration start position p1 'and the acceleration end position p2' are obtained based on the times t1 and t2 as follows. p ₁ ′ = p ₁ − (v ₁ ² −v ₁ ′ ² ) / 2a _max (26) p ₂ ′ = p ₂ − (v ₂ ² −v ₂ ′ ² ) / 2a _max (27) In this case, The end point of the linear trajectory 1 is moved from the position p1 to the deceleration start position p1 ', and the start point of the linear trajectory 2 is moved from the position p2 to the acceleration end position p2'.

As described above, when the second modified transition trajectory generation method is applied, the coating gun 1d moves in the deceleration section from the deceleration start position p ₁ 'to the position p ₁ after passing through the linear trajectory 1. It is decelerated from the moving speed v1 to the corrected moving speed v1 ', and further moves along the transition trajectory after speed adjustment from the position p1 to the position p2. Then, in the acceleration section from the position p2 to the acceleration end position p2 ′, the vehicle moves along the straight track 2 after being accelerated from the corrected moving speed v2 ′ to the moving speed v2.

[Third Modified Transition Trajectory Generation Method] Next,
FIG. 8 is an explanatory diagram showing a method for generating a third modified transition trajectory. This method adjusts the start point and the end point of the transition trajectory so that the folding width is within the operation region.

That is, when the turn-back width L exceeds the operation area indicated by the broken line by the distance K, the position p1 of the start point and the position p2 of the end point of the transition trajectory are moved inward toward the operation area by the distance K. Let For this purpose, the correction start point position p1 ″ and the correction end point position p2 ″ of the transition trajectory are obtained by the following equations, and the transition trajectory after the turning start position adjustment as shown in the figure is calculated. p1 "= p1-K (28) p2" = p2-K (29)

In this case, when the coating gun 1d moves along the linear trajectory 1 to the correction start position p1 ", it follows the transition trajectory after the turning start position adjustment from the correction start position p1" to the correction end position p2 ". To move the correction end point p
It will move from 2 "along a linear trajectory 2.

In the above-mentioned embodiment, the painting robot is described as an example, but the present invention is not limited to this and can be applied to other industrial robots. That is, in an industrial robot that moves along a trajectory generated from prestored data, if the operation area is limited, the industrial robot can be operated by using the trajectory correction method shown in the present invention. It can be operated without any trouble.

[0082]

As described above, the industrial robot according to the present invention has the following effects. (1) According to the first aspect of the invention, in an industrial robot that generates a trajectory based on prestored data and moves the work means along the trajectory to perform a predetermined work on a work target. A control means for generating a trajectory based on the data, storing an operation area indicating an allowable range of movement of the working means, and correcting the trajectory so that the trajectory falls within the operation area when the trajectory deviates from the operation area. Therefore, even if the original operation area of the industrial robot is limited, the trajectory is corrected according to the operation area. Therefore, the operation of the industrial robot is prevented from being hindered, and the work can be performed efficiently. (2) According to the second aspect of the invention, when the data is teaching data given by teaching, the reproduction trajectory is automatically corrected according to the operation area, so that the teaching work can be suppressed and the teaching work can be suppressed. The efficiency can be improved. (3) According to the third aspect of the invention, when it is detected that the transition trajectory indicating the turning back from one teaching point to the next teaching point deviates from the operation area, the position data of each teaching point is operated. Equipped with control means that automatically corrects the transition trajectory so that it is within the operation area by correcting it so that it moves to the inside of the area, and there is no need to make fine adjustments to the placement of the work object, facilitating work planning. can do. (4) Further, since the trajectory is automatically corrected so as to be within the operation area, even if the worker is a beginner, it is possible to easily teach. (5) Since the movable range of the industrial robot can be effectively utilized, it is possible to perform work on a work object having a size larger than before.

[Brief description of drawings]

FIG. 1 is a flowchart showing details of a coating trajectory generation procedure by a controller in an embodiment of an industrial robot according to the present invention.

FIG. 2 is a system configuration diagram showing an overall configuration of an embodiment of an industrial robot according to the present invention.

FIG. 3 is a block diagram showing an electrical configuration of an embodiment of the industrial robot according to the present invention.

FIG. 4 is a block diagram showing an electrical configuration of an industrial robot according to an embodiment of the present invention.

FIG. 5 is a plan view showing an operation area of the coating robot in the embodiment of the industrial robot according to the present invention.

FIG. 6 is an explanatory diagram showing a method for generating a first modified transition trajectory in the embodiment of the industrial robot according to the present invention.

FIG. 7 is an explanatory diagram showing a second modified transition trajectory generation method in the embodiment of the industrial robot according to the present invention.

FIG. 8 is an explanatory diagram showing a third modified transition trajectory generation method in the embodiment of the industrial robot according to the present invention.

[Explanation of symbols]

A wall B worktable C coating object 1 robot arm 1a first arm 1b second arm 1c wrist 1d coating gun 2 controller 2a CPU (central processing unit) 2b ROM (read only memory) 2c RAM (read / write memory) 2d Motor driver 3 Hand operation panel 4 Motor p1 Position of teaching point 2 p2 Position of teaching point 3 ps Position at moving time T / 2 p1 'Deceleration start position p2' Acceleration end position p1 "Transition orbit correction start position p2" Transition trajectory correction end position p (t _k) the moving speed of the spray gun in the moving speed v2 teaching point 3 of the spray gun in a function v1 teaching point 2 showing the transfer orbit v1 ', v2' of the spray gun in the modified travel speed T transfer orbit Travel time K Distance over operating area L, L'Folding width Xmin Lower limit in X-axis direction in operating area Upper limit position of the Y-axis direction in the lower limit position Ymax operation region in the Y-axis direction in the upper limit position Ymin operation region of the X-axis direction in the Xmax operating region

Claims (3)

[Claims] 1. An industrial robot that generates a trajectory based on pre-stored data and moves a work means along the trajectory to perform a predetermined work on a work object, wherein the trajectory is based on the data. And stores an operation area indicating an allowable range of movement of the working means,
An industrial robot comprising a control means for correcting the trajectory so that the trajectory falls within the operation area when the trajectory deviates from the operation area. 2. The teaching data is teaching data stored by teaching, and the teaching data comprises position data of a plurality of teaching points and moving speed data of a working means at the teaching points. The described industrial robot. 3. When the control means detects that a transition trajectory indicating a turn from one teaching point to the next teaching point deviates from the operation area, the position data of each teaching point is set inside the operation area. The industrial robot according to claim 2, wherein the transition trajectory is corrected so that the transition trajectory is within the operation region by correcting the transition trajectory.