JP2003103481A - Attitude optimizing method and attitude optimizing device for articulated robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To verify a proper attitude for suppressing a transit time or a deviation amount when operating an articulated robot in a matter of minutes. SOLUTION: Sixteen attitudes of the articulated robot 50 in a teaching attitude point P1 is calculated (step S2), and respective transit times from an initial specific attitude are determined and considered as motion path candidates (step S3). Sixteen attitudes per each motion path are calculated in regard to a next teaching attitude point Pn (step S4), and transit times from a precedent stage are determined (step S5). One with the shortest transit time is selected per each motion path (step S6). When the steps S4-S6 are finished in all teaching attitude points (step S8), the total sum of acting times of the motion paths is calculated (step S8), and one with the shortest transit time is selected (step S9).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a posture adjusting method and an adjusting device for an articulated robot, and in particular, an end effector provided at the tip of the articulated robot moves from a predetermined starting point to a reaching point. The present invention relates to a posture adjusting method and an adjusting device of an articulated robot for setting a path for performing the action.

[0002]

2. Description of the Related Art Conventionally, when an articulated robot installed on a manufacturing line is directly operated to teach a work posture, an operator who is familiar with the operation of the articulated robot must perform the work on the site of the manufacturing line. Therefore, the work becomes inefficient accordingly. Further, since the work needs to be performed while the production line is stopped, the operating rate of the production line also decreases.

Therefore, in recent years, in order to improve the efficiency of the teaching work or to improve the operating rate of the manufacturing line, offline teaching (offline teaching) is performed. That is, a model of an articulated robot and a work and a peripheral structure which are work objects is constructed on a computer, teaching data is created using this model, and then the teaching data is supplied to the articulated robot on site. By doing so, it is not necessary to stop the manufacturing line while creating the teaching data.

Further, in the case of a multi-joint robot for welding or the like, predetermined welding points are determined in advance, and welding is performed by bringing a welding electrode into contact with these welding points. Therefore, the posture of the gun unit provided at the tip of the articulated robot is determined by the welding point,
For off-line teaching, a welding point may be used as a teaching posture point of an articulated robot.

[0005]

Even if a welding point is given as a teaching posture point, it is often impossible to determine the posture of the articulated robot into one by using only that information. That is, the welding point only gives the position and inclination of the gun unit, and a plurality of combinations can be established for the other motion axes of the articulated robot.

As a result, for example, a multi-joint robot having a certain structure can take 16 different postures with respect to a predetermined welding point, and when creating teaching data for sequentially welding 20 welding points. , There are only 16 ²⁰ ≈1.2 × 10 ²⁴ combinations of motion paths considering the posture at each welding point.

Although it is desirable that the operating time of the articulated robot is short, as shown in FIG. 14, even if the path 1 having the shortest movement time is selected from the specified posture to the teaching posture point 1, the teaching posture is reduced. In some cases, the moving time from point 1 to teaching posture point 2 is long, and the moving time on route 2 is short.

On the other hand, it is unrealistic to verify the operating time for all of these combinations. This is because, assuming that it takes 0.01 [sec] using a computer to verify one operation path,
This is because it takes 3.8 × 10 ¹⁴ [years] to perform all the 1.2 × 10 ²⁴ verifications in the above example. If the number of welding points is 20 or more, this time further increases exponentially.

In order to compare not only the verification time but also all 1.2 × 10 ²⁴ operation path candidates, a storage capacity commensurate with this is required, but there is currently no such storage device. .

This is not a problem limited to articulated robots for welding, but a problem common to general articulated robots.

Further, as the parameter to be suppressed, not only the moving time but also the verification of suppressing the deviation amount of the operation or the energy amount consumed in the operation has the same problem.

The present invention has been made in consideration of such a problem, and it is possible to verify in a short time an appropriate posture for suppressing a movement amount when operating an articulated robot. An object of the present invention is to provide a posture optimizing method and an optimizing device for a joint robot.

[0013]

A method for optimizing a posture of an articulated robot according to the present invention uses a prescribed posture as a starting point, and according to a plurality of taught posture points which define a position and an inclination with respect to a specific portion of the articulated robot, In the posture optimization method of the articulated robot for operating the articulated robot,
A first step of obtaining a plurality of possible first postures of the articulated robot at the first teaching posture point and setting the first postures as motion path candidates respectively; A second step of obtaining a movement amount for moving to the plurality of first postures;
The third step of obtaining a plurality of possible second postures of the articulated robot at the second taught posture point, and the plurality of second postures from one or more postures of the plurality of first postures.
A fourth step of obtaining a movement amount for moving to the posture and a plurality of second postures having the smallest movement amount obtained in the fourth step are selected and recorded for each of the movement path candidates. And a fifth step of

Then, the third to fifth steps are repeated, and the same processing as the processing for the second teaching posture point is performed for the third and subsequent teaching posture points.
The movement path candidate may be set by obtaining the minimum movement amount with respect to the immediately preceding teaching posture point.

Further, the third to fifth steps may be performed for all of the motion path candidates for each of the taught posture points.

Further, with respect to one motion path candidate among the motion path candidates, the third to fifth steps are repeatedly performed up to the teaching posture point having a predetermined number, and then the third motion path candidate is subjected to the third motion path candidate. The fifth step may be repeated until the teaching posture point having the predetermined number.

Furthermore, the movement amount may be a movement time, a deviation amount or an energy amount.

Of the movement path candidates corresponding to the plurality of first postures, the one having the smallest total movement amount may be selected.

The specified posture may be set after the final teaching posture point.

In addition, the posture-optimizing apparatus for an articulated robot according to the present invention defines the articulated robot as a starting point, and controls the articulated robot according to a plurality of taught posture points that define the position and inclination of a specific portion of the articulated robot. In a posture adjusting device for an articulated robot to operate, a posture calculation unit that obtains a plurality of possible postures of the articulated robot at the taught posture point, and a section movement that obtains a movement amount for moving between predetermined postures The time calculation unit and the one having the minimum movement amount calculated by the section movement time calculation unit are selected and recorded in the motion path candidates corresponding to the plurality of first postures of the articulated robot at the first teaching posture point. And a movement route selection unit that selects a movement route candidate having the smallest total movement amount among the movement route candidates.

Thus, even if there are a plurality of possible postures of the articulated robot at each taught posture point, the combination of the postures is prevented from exponentially increasing, and the movement time or the time of operating the articulated robot is reduced. It is possible to verify an appropriate posture for suppressing the movement amount such as the deviation amount in a short time.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a posture adjusting method and an adjusting device for an articulated robot according to the present invention will be described below with reference to FIGS.

Basically, the posture adjusting method and the adjusting device of the articulated robot according to the present embodiment basically find 16 possible postures of the articulated robot at the first taught posture point, and 16 types of motion path candidates corresponding to the posture are set. With respect to these motion path candidates, one having the shortest movement time is selected from the 16 postures at the next taught posture point and sequentially recorded.

As shown in FIG. 1, an off-line teaching device (posture optimization device) 10 used in the present embodiment teaches the operation of the articulated robot 50, and works based on the created teaching data. Robot device 1 for performing desired work on an object
It is linked to 2.

The robot apparatus 12 also comprises an articulated robot 50 and a robot controller 24 for controlling the operation of the articulated robot 50 based on teaching data.

As shown in FIG. 2, the control unit 14 constituting the offline teaching apparatus 10 has a C functioning as a control means for controlling the entire offline teaching apparatus 10.
PU (computer) 26 and ROM 28 that is a storage unit
A hard disk drive (HDD) for accessing data to the RAM 29 and the hard disk 34.
39, a drawing control circuit 30 for controlling drawing on the screen of the monitor 16, and an interface circuit 32 to which the keyboard 18 and the mouse 20 as input devices are connected.
And a recording medium drive 36 that controls an external recording medium 36a (for example, a flexible disk or a compact disk).

The hard disk 34 stores a posture optimization program 35 having a function of optimizing the movement path of the articulated robot 50, an OS (not shown), and the like.

As shown in FIG. 3, an articulated robot 50
Is a second base 56, a first link 58, a second link 60, a third link 62, a fourth link 64, and a gun attaching / detaching portion 66 in order from the first base 54, which is a mounting base, toward the distal end side. Are connected. A gun unit (end effector) 68 is connected to the gun attaching / detaching portion 66 at the tip.

The second base 56 is pivotally supported with respect to the first base 54 about an axis J1 which is a vertical axis. The base end of the first link 58 is pivotally supported on the second base 56 by a shaft J2 which is a horizontal shaft. Further, the base end portion of the second link 60 is swingably supported on the tip end portion of the first link 58 by a shaft J3 which is a horizontal shaft. The third link 62 is connected to the tip end side of the second link 60 with the axis J4 as a common rotation center axis. Further, the base end portion of the fourth link 64 is pivotally supported on the tip end portion of the third link 62 by a shaft J5 perpendicular to the shaft J4. The gun attaching / detaching portion 66 is connected to the tip end side of the fourth link 64 with the axis J6 as a common rotation center axis.

The shafts J4 and J6 have a movable range of two rotations, that is, 720 ° in consideration of the operational margin.

The gun unit 68 connected to the gun attaching / detaching portion 66 is a so-called C-type welding gun, and has a pair of electrodes 70 and 72 which are opened and closed along the axis J6 at both ends of the arch-shaped arm 74. When the electrodes 70 and 72 are in the closed state, the welding work point (hereinafter TCP (Tool Center Po
int). ) To contact the work 80.

A direction that coincides with the axis of the electrode 72 on the main body side from TCP is defined as a vector Zr, and a direction that is orthogonal to the vector Zr and faces the outside of the gun unit 68 is defined as a vector Xr. Further, a vector Yr is a direction orthogonal to the vector Xr and the vector Zr.

The drive mechanism for the shafts J1 to J6 and the electrodes 70,
The opening / closing mechanism 72 is driven by an actuator (not shown), and the TCP is determined by the values of the rotation angles θ1 to θ6 of the axes J1 to J6 and the dimensions of each part of the articulated robot 50.

The gun unit 68 is not limited to the C-type welding gun, but is, for example, an X-type welding gun (a welding gun having a pair of opening and closing gun arms pivotally supported by a common support shaft) 68a shown in FIG. Good.

As a reference point for coordinate calculation and control of the articulated robot 50, the point where the axis J1 and the axis J2 intersect is defined as an origin O, and with this origin O as a reference, the vertical upward direction is a height Z, When the rotation angle θ1 is θ1 = 0, the direction of the axis J2 is represented as depth Y, and the height Z and the direction perpendicular to the depth Y are represented as width X. The height Z, the width X, and the depth Y indicate three-dimensional orthogonal coordinates.

As shown in FIG. 5, the posture optimization program 35 has a work point coordinate reading section 100 having a function of reading data from the RAM 29, the hard disk 34 and the like.
And a robot posture calculation unit 102 having a function of obtaining the rotation angles of the axes J1 to J6 of the articulated robot 50 from the position and inclination of the gun unit 68, and a section for obtaining the time for the articulated robot 50 to move between predetermined postures. Travel time calculation unit 1
04, and the shortest movement time calculation unit 106 that obtains the shortest time of the movement time between the predetermined postures.

In addition, the posture optimization program 35 is required to move the robot posture selecting unit 108 for selecting the posture that provides the shortest movement time in movement between postures and the movement path connecting a plurality of taught posture points. It has a robot cumulative movement time calculation unit 110 for calculating time, and a movement route selection unit 112 having a function of selecting one of a plurality of movement routes having the shortest movement time.

The same functions as those of the robot posture calculation unit 102 and the section movement time calculation unit 104 are also provided in the robot control unit 24.

Further, the posture optimization program 35 has an image display section 116 for setting the posture data of the articulated robot 50 in a robot model defined by three-dimensional CAD and drawing it.

The image display unit 116 monitors a model of an articulated robot or a predetermined graph using an API (Application Programming Interface) by a robot posture setting command set by an operator and a drawing command.
It has a function to draw on the screen of 6.

As shown in FIG. 6, the prescribed posture P0 and the teaching posture point Pn (n =
Path table 1 for recording postures in 1, 2, 3 ...
80 is a "gun unit orientation" column 180a, "TCP
No. ”column 180b and“ each axis angle ”column 180c. The“ each axis angle ”column 180c indicates the rotation angle θ1.
.About..theta.6.

The "gun unit orientation" column 180a is 3
It represents the inclination of the gun unit 68 in the dimensional space and is represented by three vectors Xr, Yr, and Zr. The “TCP position” column 180b represents the position of TCP in the three-dimensional space in the X, Y, Z coordinate system with the origin O as a reference.

The "each axis angle" column 180c indicates the posture of the articulated robot 50 by the rotation angles θ1 to J1 of the axes J1 to J6.
This is represented by θ6.

In the first order "0" and the last order "21", P0 is set as the specified posture. That is, it indicates that the operation path created based on the path table 180 returns to the original posture after performing a predetermined operation such as welding.

Further, regarding the specified posture point P0, the "each axis angle" column 180c is recorded in advance. For the other teaching posture points P1 to P20, only the “gun unit orientation” column 180a and the “TCP position” column 180b are recorded. This is the teaching posture points P1 to P20.
Is inevitably determined from the position of the welding point for welding the work 80, the application of the electrodes 70 and 72 vertically to the surface of the work 80 at that point, and the vector Xr indicating the direction of the gun unit 68. .

In practice, this path table 180 teaches not only the welding points but also the path along the way, but for the sake of convenience, points other than the welding points are omitted.

Further, the path table 18 in the state shown in FIG.
It is assumed that 0 is recorded in the hard disk 34 in advance.

As shown in FIG. 7, the movement time recording table 190 has a "movement time" column 190a in which the movement time between each teaching posture point is recorded for 16 movement path candidates.
And a "total" column 190b for calculating and recording the total. The travel time recording table 190 is a readable / writable table stored in the RAM 29.

Next, before explaining the procedure for optimizing the posture of the articulated robot 50, the function of the robot posture calculation unit 102 will be described. The robot posture calculation unit 102
A total of 6 parameters of the “gun unit orientation” column 180a and the three parameters of the “TCP position” column 180b recorded in the path table 180, ie, 6 parameters in total, are used to indicate the posture of the articulated robot 50 “each axis angle”. The rotation angles θ1 to θ6 of the column 180c are obtained.

The position and inclination of the gun unit 68 in space are determined by the above six parameters.
If these six parameters are expressed as a determinant A6, the determinant A6 is obtained by a function f having variables of the rotation angles θ1 to θ6, and is expressed by the following equation (1).

A6 = f (θ1, θ2, θ2, θ3, θ4, θ5, θ6) (1) Conversely, in order to obtain the rotation angles θ1 to θ6 from the determinant A6, the reverse operation of the function f is performed. The function f ^-1 is performed, which is obtained by the following equation (2).

(Θ1, θ2, θ2, θ3, θ4, θ5, θ6) = f ⁻¹ (A6) (2) This equation (2) is actually expressed in the form of simultaneous equations. , When the simultaneous equations are solved, there may be a plurality of combinations of solutions. This means that the articulated robot 5
The number of possible postures of 0 indicates that there are a plurality of postures.

Articulated robot 50 according to the present embodiment
In the case of the above structure, there are about 16 solutions. That is, as shown in FIG. 8A, the axis J2, the axis J3, and the axis J5.
Depending on the rotation angle of the gun unit 68, the so-called elbow is raised and the elbow is lowered (Fig. 8).
(See the double-dotted line of A)).

Further, as shown in FIGS. 8B and 8C, the axis J
It is possible to reverse the mutual positional relationship between the third link 62 and the fourth link 64 in No. 4, and two positions can be taken at this position.

Further, since the movable range of each of the shaft J4 and the shaft J6 is 720 °, two angles (for example, 10 ° and 370 °) can be set in order to set a predetermined orientation.

From these, it can be seen that the articulated robot 50 can normally take 2 ⁴ = 16 different postures based on the six parameters indicating the position of the gun unit 68. The robot posture calculation unit 102 calculates these 16 postures.

Next, the off-line teaching device 10 and the posture optimizing program 35 thus configured.
A procedure for optimizing the posture of the articulated robot 50 will be described with reference to FIGS. 9 to 11.

In step S1 of FIG. 9, the work point coordinate reading unit 100 first causes the path table 18 shown in FIG.
0 is read from the hard disk 34 and stored in the RAM 29.

Next, in step S2, the robot posture calculation unit 102 uses the data of the "gun unit direction" column 180a and the "TCP position" column 180b for the teaching posture point P1 recorded in the path table 180. 16 postures of the articulated robot 50 are calculated and all of them are stored. Since there may be less than 16 combinations depending on the data, only the obtained combinations are stored in that case.

For the order 21 of the path table 180, the specified posture point P0 is recorded as the final stage. Since the posture has already been determined for this defined posture point P0, step S2 is omitted.

Next, in step S3, the section movement time calculation unit 104 causes the specified posture point P0 which is the specified posture.
From the movement path candidates 1 to 16
And The travel time calculated for these operation route candidates 1 to 16 is the “travel time” column 1 of the travel time record table 190.
Record in the leftmost column of 90a.

Next, in step S4, with respect to the next taught posture point Pn in the path table 180, 16 postures of the articulated robot 50 are calculated by the same procedure as in step S2. The 16 posture data obtained are RA
It is temporarily stored in M29 or the like.

The operation path candidates at this point are shown in FIG.
As shown in FIG.
There are six types of operation paths (see the broken line in FIG. 10). That is, 16 ² = 256 operation paths can exist.

Next, in step S5, the section movement time calculation unit 104 obtains the movement time from the posture of the teaching posture point Pn at the preceding stage for the 16 movement routes corresponding to the respective movement route candidates 1 to 16. .

Next, in step S6, the shortest movement time calculation unit 106 selects the movement route having the shortest movement time among the 16 movement routes corresponding to the movement route candidates 1 to 16.

That is, as shown in FIG. 11, one of the postures of the articulated robot 50 at the teaching posture point P2 is selected for each of the motion path candidates 1 to 16. As a result, it is possible to suppress the combinations existing in 256 ways to 16 ways.

The posture data for which the shortest movement time is calculated by the shortest movement time calculation unit 106 is transmitted to the robot posture selection unit 108, and is further stored in the RAM 29. Other posture data is released from the memory. The travel time corresponding to the selected operation route is recorded in association with each of the operation route candidates 1 to 16 in the travel time recording table 190.

Next, in step S7, it is confirmed whether or not the processing has been completed for all the teaching posture points Pn, and if they have been completed, the process proceeds to the next step S8. If the unprocessed teaching posture point Pn remains, the process returns to step S4, and the process is continued in the order shown in the path table 180.

In the next step S8, the robot cumulative movement time calculation unit 110 causes the movement time recording table 19
Based on 0, the cumulative total of the operation times of the operation path candidates 1 to 16 is calculated. The calculated result is the "total" column 190b
To record.

Next, in step S9, the movement route selection unit 112 selects the movement route candidate having the shortest travel time from the movement route candidates 1 to 16 based on the result recorded in the "total" column 190b. Operation path.

Finally, in step S10, the posture data of the articulated robot 50 at the teaching posture points P1 to P20 corresponding to the movement path selected by the movement path selection unit 110 are represented as rotation angles θ1 to θ6.

The calculated rotation angles θ1 to θ6 are recorded in the “each axis angle” column 180c which is blank in the order 1 to 20 in the example of the path table 180 shown in FIG.

Next, a modification of the above-described embodiment will be described with reference to FIG.

In the above-described embodiment, steps S4 to S4.
6 shows an example in which the movement time is calculated in parallel for the movement route candidates 1 to 16, but in the present modification, the movement time is calculated individually for each movement route candidate 1 to 16. is there.

In FIG. 12, steps S101 to S1.
Step 03 is the same process as that of steps S1 to S3 described above.
The movement time recording table 190 (see FIG. 7) is calculated by calculating the movement time between the 16 postures and the specified posture point P0.
To record. Motion paths corresponding to these 16 postures are defined as motion path candidates 1 to 16.

In the next step S104, the counter i indicating one of the motion path candidates 1 to 16 is set to the initial value "1".

Next, in step S105, the counter n indicating the order of the teaching posture points Pn is set to the initial value "2". In addition, the teaching posture point immediately before the teaching posture point Pn is set to P.
It shall be represented as (n-1).

Next, in step S106, with respect to the teaching posture point Pn in the path table 180, 16 postures of the articulated robot 50 are calculated by the same procedure as in step S2. The 16 posture data thus obtained are temporarily stored in the RAM 29 or the like.

The number of possible postures may not be 16 depending on the posture of the gun unit 68.
In that case, processing may be appropriately performed according to the number of possible postures.

Next, in step S107, for the motion path candidate i, the 16 postures obtained in step S106 and the teaching posture point P (n-
Calculate the travel time between 1). This processing is performed by the section travel time calculation unit 104.

Next, in step S108, the shortest movement time calculation unit 106 selects the movement path candidate i having the shortest movement time among the 16 operation paths branched in step S107.

The movement time corresponding to the selected posture is recorded in the column of the movement path candidate i of the movement time recording table 190.

Next, in step S109, it is confirmed whether or not the counter n indicates the final value. That is, in the example of the path table 180, it is confirmed whether or not it is “20” indicating the teaching posture point P20.

If the counter n is the final value, the process proceeds to the next step S111, and if it is less than the final value, the counter n is incremented by "1" (step S110) and the process returns to step S106.

In step S111, the robot cumulative movement time calculation unit 110 causes the movement time recording table 19
Based on 0, the cumulative total of the operation time of the operation route candidate i is calculated. The calculated result is recorded in the "total" column 190b corresponding to the motion path candidate i.

Next, in step S112, it is confirmed whether or not the counter i indicates the final value "16". If the counter i is "16", the next step S1
14, the counter i is set to "1" if it is less than "16".
Increment (step S113) and return to step S105. Next, in step S114, as in step S9, one of the movement route candidates 1 to 16 having the shortest travel time is selected to determine the final movement route. To do.

Finally, in step S115, the rotation angles θ1 to θ6 indicating the posture of the articulated robot 50 are recorded in the path table 180, as in step S10.

As described above, according to the present embodiment and its modification, a plurality of possible postures of the articulated robot 50 at the first taught posture point P1 are obtained, and the movement path is made to correspond to the plurality of postures. Set candidates. Then, at the teaching posture point Pn in the subsequent stage, the movement time between the plurality of possible postures of the articulated robot 50 at the teaching posture point Pn and the posture in the preceding stage is calculated, and the posture which becomes the shortest movement time is calculated. I have decided to choose.

As a result, in the brute force combination method, the number of combinations of motion paths that exponentially increase can be suppressed within a reasonable range. Moreover, since the shortest movement time is selected and recorded, an appropriate posture can be selected from the viewpoint of the movement time.

Especially when the number of welding points is large,
The verification time increases in proportion to the number of welding points, but does not increase exponentially. More specifically, if it is executed using a computer, it can be executed in a few minutes to a few hours.

Further, the first taught posture point P1 from the specified posture
With respect to the movement up to, the movement path candidates corresponding to a plurality of postures are set, so that the posture of the articulated robot 50 can be optimized with particular emphasis placed on this period.

In the final stage, the first specified posture point P0
Since the same posture is set, it is possible to perform the movement in a short movement time even when repeatedly performing the movement.

In the above-mentioned embodiment, the same posture as the first prescribed posture point P0 is set in the final stage of the path table 180, but it is necessary to consider the time to return to the prescribed posture after welding is completed. If there is not, the moving time during this period may be ignored.

Depending on the form of the path table 180, the teaching posture points P3 to P may be applied to all the teaching posture points P1 to P20, as shown in FIG. 13, for example.
As shown in 10, it may be applied only to an appropriate section. In this case, the taught posture point P3 may be defined as the defined posture.

Further, in the above-described embodiment, an example in which the gun unit 68 is regarded as the specific portion indicating the teaching posture and the posture of the articulated robot 50 is obtained based on the position and the inclination thereof has been described. The attitude may be calculated from the information of.

Furthermore, in the above example, the moving time is optimized as the parameter of the moving amount, but the parameter to be processed is not only the moving time but also the deviation amount or the energy consumption amount. Good. That is, the life of the articulated robot 50 can be extended by evaluating the angular deviations of the rotation angles θ1 to θ6 of the axes J1 to J6 by an appropriate evaluation function and suppressing the rotation amount of the axes J1 to J6. At the same time, excessive posture changes can be suppressed.

If the amount of energy [J] or the work rate [W] for operating the articulated robot 50 is suppressed, the energy consumption can be reduced and the equipment of the energy supply source can be made small. .

In addition, the articulated robot 50 has, for example, 7
Different structures such as a shaft structure and a structure including a link mechanism may be used.

The posture adjusting method and the adjusting device for an articulated robot according to the present invention are not limited to the above-described embodiments, and needless to say, various configurations can be adopted without departing from the gist of the present invention. Is.

[0100]

As described above, according to the posture adjusting method and the adjusting device of the articulated robot according to the present invention, the movement amount such as the movement time or the deviation amount when operating the articulated robot is suppressed. The effect of being able to verify the proper posture for doing in a short time is achieved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an offline teaching device and a robot device used in the present embodiment.

FIG. 2 is a block diagram showing a configuration of an offline teaching device.

FIG. 3 is an explanatory diagram showing a configuration of an articulated robot.

FIG. 4 is an explanatory view showing an X-type welding gun.

FIG. 5 is a block diagram showing the configuration of a posture optimization program.

FIG. 6 is an explanatory diagram showing a path table.

FIG. 7 is an explanatory diagram showing a travel time recording table.

FIG. 8A is an explanatory diagram showing the relationship between the first link and the second link of the articulated robot when the position of the gun unit is fixed, and FIG. 8B shows the third link more than the fourth link. It is an explanatory view showing an example located on the front side,
FIG. 8C is an explanatory diagram illustrating an example in which the fourth link is located on the front side of the third link.

FIG. 9 is a flowchart showing a procedure of a posture optimization method for an articulated robot according to the present embodiment.

FIG. 10 is an explanatory diagram showing that there are 256 motion paths up to the second taught posture point.

FIG. 11 is an explanatory diagram showing a state in which a short moving time is selected at the second teaching posture point and the number of movement paths is reduced to 16 ways.

FIG. 12 is a flowchart showing a procedure of a posture optimization method for an articulated robot according to a modified example of the present embodiment.

FIG. 13 is an explanatory diagram showing an example in which the posture is optimized for a predetermined intermediate area of the taught posture points.

FIG. 14 is an explanatory diagram showing that even when the shortest time posture between the teaching posture points is selected, the movement time as a whole may not be the minimum in the selection of the motion path.

[Explanation of symbols]

10 ... Offline teaching device 12 ... Robot device 14 ... Control unit 16 ... Monitor 20 ... Mouse 24 ... Robot control unit 26 ... CPU 29 ... RAM 35 ... Posture optimization program 50 ... Articulated robot 68 ... Gun unit 70, 72 ... Electrode 80 ... Work 100 ... Work point coordinate reading unit 102 ... Robot posture calculation unit 104 ... Section movement time calculation unit 106 ... Shortest movement time calculation unit 108 ... Robot posture selection unit 110 ... Robot cumulative movement time calculation unit 112 ... Motion path selection unit 180 ... Path table 190 ... Moving time recording table P0 ... Specified posture points P1 to P20 ...
Teaching posture point

Continued front page    (72) Inventor Kaoru Shibata             1-10-1 Shinsayama, Sayama City, Saitama Prefecture             Engineering Co., Ltd. F term (reference) 3C007 AS11 BS12 BT08 CT05 CV08                       CW08 LS10 LS15 LS20 MT01                 5H269 AB12 AB33 BB09 CC09 DD06                       QC10 SA10 SA11

Claims (8)

[Claims] 1. A posture optimization method for a multi-joint robot for operating a multi-joint robot according to a plurality of teaching posture points, which define a position and a tilt for a specific portion of the multi-joint robot, starting from a predetermined posture. A first step of obtaining a plurality of possible first postures of the articulated robot at the first taught posture point and setting the first postures as motion path candidates, respectively; A second step of obtaining a movement amount for moving to the plurality of first postures; a third step of obtaining a plurality of second postures that the articulated robot can take at a second taught posture point; A fourth step of obtaining a movement amount for moving from one or more of the first postures to the plurality of second postures; Chi, the moving amount calculated by the fourth step is to select the smallest, the fifth step and the orientation optimization method of the articulated robot, characterized in that it comprises a recording for each of the operation path candidate. 2. The posture optimization method for an articulated robot according to claim 1, wherein the third to fifth steps are repeated to perform the second teaching posture with respect to the third and subsequent teaching posture points. A posture optimization method for an articulated robot, which performs the same process as a process for a point and obtains a minimum movement amount with respect to the previous teaching posture point and sets the motion path candidate. 3. The posture optimizing method for an articulated robot according to claim 2, wherein the third to fifth steps are performed for all of the motion path candidates for each of the taught posture points. Posture optimization method for articulated robot. 4. The posture optimizing method for an articulated robot according to claim 2, wherein one motion path candidate among the motion path candidates is
The third to fifth steps are repeatedly performed up to the teaching posture point of a predetermined number, and then the third to fifth steps are repeatedly performed up to the teaching posture point of the predetermined number for another motion path candidate. A posture optimization method for an articulated robot characterized by the following. 5. The posture optimization method for an articulated robot according to claim 1, wherein the movement amount is a movement time, a deviation amount, or an energy amount. Posture adjustment method. 6. The posture optimization method for an articulated robot according to any one of claims 1 to 5, wherein among the movement path candidates corresponding to the plurality of first postures, the total movement amount is the smallest. A posture-optimizing method for an articulated robot, characterized by selecting objects. 7. The articulated robot posture adjusting method according to claim 1, wherein the specified posture is set after the final taught posture point. Robot posture optimization method. 8. A posture adjusting device for a multi-joint robot for operating a multi-joint robot according to a plurality of teaching posture points, which define a position and a tilt for a specific portion of the multi-joint robot, starting from a predetermined posture. A posture calculation unit that obtains a plurality of possible postures of the articulated robot at the taught posture point, a section movement time calculation unit that obtains a movement amount for moving between predetermined postures, and a section movement time calculation unit A shortest movement time calculation unit that selects a movement amount that is the smallest and records it in a movement route candidate corresponding to a plurality of first postures that the articulated robot can take at the first taught posture point; A posture optimization apparatus for an articulated robot, comprising: a motion path selection unit that selects a robot having a minimum total movement amount.