JPH0919880A - Method and device for controlling movable body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control method and a device for a movable body which can correct the compression in the height direction of multiply tiered works. SOLUTION: S1, see the A robot arm and a finger are moved (S1) to over works. A position A in the height direction before correction in the case of N-tiered works from the height H of the works is calculated (S2) by using a formula A=H(N-1)+Z0. The position A in the height calculated at S2 with a correction value B as a compression value in the height direction of a unit work is corrected and a position Z in the height direction after correction is calculated (S3) by using a formula Z=A-(N-1)B. A finger is shifted (S4) to a position Z calculated at S3, the works are clamped (S5) the finger is moved overhead in a condition where the work is clamped and the grasping motion of the work at N'th tier is completed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial robot, which is a typical moving body, and a height control correction method for the robot.

[0002]

2. Description of the Related Art Conventionally, industrial robots such as palletizing robots that grip workpieces such as stacked boxes and plastic containers and move them to another place by a predetermined operation have a method as shown in FIGS. Is being done in.

FIG. 4 is a side view showing a gripping position of a work as the first conventional example.

In FIG. 4, the work is a stack of 5 stages, and 10
1 is the position of the work in the case of 1-step stack, 102 is the position of the work in the case of 5-step stack, 103 is the position of the robot finger in the case of 1-step stack, and 104 is the position of the robot finger in the case of 5-step stack. is there. In this case, the value Z in the height direction when the robot finger grips the work of the Nth stage is H, and H1 is set to such an extent that the work and the finger do not contact each other when gripping the first stage. When such Z0 is determined, Z = H (N-1) + Z0.

FIG. 5 is a side view showing a gripping position of a work as the second conventional example.

In FIG. 5, the work is a stack of 5 and is 20
Reference numerals 1 to 205 represent the positions of the workpieces in the N-stage stack, and 206 to 210 represent the positions of the robot fingers in the N-stage stack.

[0007]

However, in the above-mentioned conventional example, in the case of conventional example 1, when H1 cannot be sufficiently obtained due to the physical positional relationship between the ground surface and the finger in determining Z0, the finger and the work or the ground surface are not able to be obtained. Contact could occur. Further, a work such as a plastic container having a certain amount of weight and containing the contents (for example, weight 30 kg, external dimensions H300 mm, W500 mm, D4
When they are stacked (about 00 mm), they are compressed in the height direction by their own weight. For this reason, in the case of multi-stage stacking, there is a problem that the error in the height direction becomes a size that cannot be ignored when gripping with fingers. In the case of the conventional example 2, since the positions of all the workpieces and the workpiece gripping positions of the fingers are stored in the teaching of the robot, the above-mentioned problem is solved, but the number of data stored in the robot becomes considerably large, and the teaching work and transfer work are performed. Considering the occurrence of work specification changes,
There was a problem that work efficiency was poor.

Therefore, an object of the present invention is to provide a control device for a moving body and a control method therefor capable of correcting the compression in the height direction of multi-layered works.

[0009]

As a structure for solving the problems of the present invention, claim 1 provides a control device for controlling a moving body for moving a plurality of stacked works according to a predetermined plan. First storage means for pre-storing the heights of individual work pieces, and second storage means for pre-storing the compressed values of the single work piece heights when the plurality of work pieces are stacked in multiple stages. And a correction unit that corrects the target movement position of the moving body based on the first and second storage units according to the number of stacked stages of the plurality of works and the height of a single unit. It is a control device for a mobile body characterized by the above.

With this, the control of the moving body is realized in consideration of the compression value of the height of the stacked works, so that the works can be always held at an appropriate position.

The control device for a moving body according to claim 1, wherein the first storage means of claim 2 can change a value depending on whether or not there is a contained object inside each of the plurality of works. is there.

This makes it possible to easily switch the correction of the height of the stacked works depending on the presence or absence of the contained items.

The control device for a moving body according to claim 1, wherein the correction amount of the moving position in the correcting means of claim 3 is a linear function of the number of stages of the plurality of stacked works. .

It is possible to always hold the work at an appropriate position according to the stacked works by simply storing the height of the work alone and its compression value.

In another configuration of the present invention for solving the same problem, in a fourth aspect of the present invention, there is provided a method for controlling a moving body which moves a plurality of stacked works according to a predetermined plan. First to store the height in advance
Based on the first storing step and the second storing step of storing in advance the compressed value of the height of the single body of the plurality of workpieces when the plurality of workpieces are stacked in multiple stages. The method for controlling a moving body is characterized by a correction step of correcting a target moving position of the moving body according to the number of stacked stages of the plurality of works and the height of a single body.

With this, since the control of the moving body is realized in consideration of the compression value of the height of the stacked works, it is possible to always hold the works at an appropriate position.

According to a fifth aspect of the present invention, in the first storage step, the value is changed depending on whether or not there is a stored item inside the plurality of works, respectively. Is the way.

This makes it possible to easily switch the correction of the height of the stacked works depending on the presence or absence of the contained items.

According to a sixth aspect of the present invention, in the method of controlling a movable body according to the fourth aspect, the correction amount of the movement position in the correction step is a linear function of the number of stages of the plurality of stacked works. is there.

By simply storing the height of each work piece and its compression value, it becomes possible to always hold the work pieces at an appropriate position according to the stacked work pieces.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below.

First, the structure of a multi-axis robot to which the present invention is applied will be described.

FIG. 1 is a side view of a multi-axis robot and a work to which the present invention is applied.

In the figure, a multi-axis robot having a finger 2 at an end of a robot arm 1 is controlled by a robot controller (not shown), and the work 3 which is a box stacked N stages by a predetermined operation is fingered. It is grasped by 2 and transferred to another place.

Next, with reference to FIG. 2, a description will be given of the case where the work 3 which is a box is stacked in six stages, and the case where there is an article contained in the work 3 and the case where there is no stored matter.

FIG. 2 is a view showing the difference in the height direction of a six-stage stacked work as one embodiment of the present invention.

In the figure, reference numeral 11 denotes a work, which is a box in which the contents are contained, which are stacked in six stages. Reference numeral 12 is a work which is a box having no contents inside, and is stacked in six stages. A is the position in the height direction at which the finger 2 holds the work, calculated from the height of the work, B is the correction value in the height direction for each stage of the work when there are contained items inside, and C is the inside Assuming that the correction values in the height direction per one stage of the work when there are no stored items, the position in the height direction of the uppermost stage is the value Z in the height direction when gripping the Nth stage work.
Is represented by: Work 11: Z = A-5B Work 12: Z = A-5C.

In consideration of the above correction, a method of calculating the position where the finger 2 grips the work in the case of N-stage product will be described with reference to FIG.

FIG. 3 is a flow chart showing the calculation processing of the work gripping position as one embodiment of the present invention.

In the figure, in step S1, the robot arm 1 and the fingers 2 are moved above the work 3. In step S2, the position A in the height direction before correction is calculated from the height H of the work 3 in the case of N steps.

A = H (N-1) + Z0 Next, in step S3, the correction value B is used in step S2.
The position A in the height direction calculated in step 1 is corrected, and the position Z in the height direction after correction is calculated.

Z = A- (N-1) B In step S4, the position Z calculated in step S3
The finger 2 is moved to, the work 3 is clamped in step S5, and the finger 2 is moved to the sky with the work 3 clamped in step S6, and the gripping operation of the work 3 at the Nth stage is completed.

In the present embodiment, the case where the stacked work pieces are gripped by the fingers to move to another place has been described, but the operation of the fingers when stacking the work pieces is similar to the above case. It goes without saying that the correction of is effective.

Further, the present invention may be applied to a system composed of a plurality of devices or an apparatus composed of a single device. Needless to say, the present invention can be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus. In this case, the storage medium storing the program according to the present invention constitutes the present invention. Then, by reading the program from the storage medium to the system or device, the system or device can operate in a predetermined manner.

<Effects of Embodiment> (1) The height H of the work 3 and the compression of the height due to its own weight when the contents are stored in the work 3 are stored in the robot as B per work, By using a linear function for correction with the number of stacked works, it is possible to always accurately hold the works 3 by the fingers 2 even when the works 3 are stacked in N steps. (2) B is the work 1 in the case where there are contained items inside
The correction value in the height direction for each step, C is the correction value in the height direction for each work step when there are no stored items inside, and two different correction values are used to teach or transfer work. It is possible to flexibly respond to changes in specifications.

[0036]

As described above, according to the present invention,
(EN) Provided are a control device for a moving body and a control method therefor capable of correcting the compression in the height direction of works stacked in multiple stages.

[0037]

[Brief description of the drawings]

FIG. 1 is a side view of a multi-axis robot and a work to which the present invention is applied.

FIG. 2 is a diagram showing a difference in a height direction of a six-stage stacked work as one embodiment of the present invention.

FIG. 3 is a flowchart showing a calculation process of a work gripping position according to an embodiment of the present invention.

FIG. 4 is a side view showing a gripping position of a work as Conventional example 1.

FIG. 5 is a side view showing a gripping position of a work as Conventional example 2.

[Explanation of symbols]

 1 robot arm 2 fingers 3 work 11 is a box with a container inside each of the work pieces 12 is a box with no container inside each of the work pieces 101 Position of the work piece in the case of one stack 102 102 of the work in the case of five stacks Position 103 Position of robot finger in case of 1-step stack 104 Position of robot finger in case of 5-step stack 201 Position of work in case of 1-step stack 202 Position of work in case of 2-step stack 203 In case of 3-step stack Work position 204 Work position in case of 4-stage stack 205 Work position in case of 5-stage stack 206 Position of robot finger in case of 1-stage stack 207 Position of robot finger in case of 2-stage stack 208 208 3-stage product Position of robot finger in case of 209 Position of robot finger in case of 4 stacks 210 Position of robot finger in case of 5 stacks

Claims (6)

[Claims] 1. A control device for controlling a moving body for moving a plurality of stacked works according to a predetermined plan, comprising: first storage means for storing in advance heights of the plurality of works alone; Second storage means for storing in advance compressed values of the heights of the plurality of workpieces when the workpieces are stacked in multiple stages, and a target of the moving body based on the first and second storage means. A controller for a moving body, comprising: a correction unit that corrects the moving position according to the number of stacked stages of the plurality of works and the height of a single body. 2. The control device for a moving body according to claim 1, wherein the first storage means is capable of changing a value depending on whether or not there is a contained object inside each of the plurality of works. 3. The moving body control device according to claim 1, wherein the correction amount of the movement position in the correction means is a linear function of the number of stages of the plurality of stacked works. 4. A method of controlling a moving body for moving a plurality of stacked works according to a predetermined plan, comprising: a first storing step of pre-storing the height of each of the plurality of works alone; A second storage step of pre-storing the compressed values of the heights of the plurality of workpieces when stacked in multiple stages, and a target movement position of the moving body based on the first and second storage steps. A method for controlling a moving body, characterized by a correction step for correcting the above according to the number of stacked stages of the plurality of works and the height of a single body. 5. The method for controlling a moving body according to claim 4, wherein in the first storing step, a value is changed depending on whether or not there is a contained object inside each of the plurality of works. 6. The method of controlling a moving body according to claim 4, wherein the correction amount of the movement position in the correction step is a linear function of the number of stages of the plurality of stacked works.