JPH09311712A - Method and unit for robot control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To flexibly cope with alterations of operations by selectively executing operation elements, obtained by dividing a series of operations by unit functions of a manipulator, according to procedures needed to perform the series of operations. SOLUTION: A moving operation element execution device 11a (level-1 precision) of the robot control unit 10 moves the hand tip of the manipulator 1 according to information from a sensor 2 and gripping operation element execution devices 12a-12c (level-1 precision, level-2 precision, and level-3 precision in order) grip a component with the hand tip of the manipulator 1. Then arranging operation element execution devices 13a-13c (level-1 precision, level-2 precision, and level-3 precision in order) arrange the gripped component at a necessary place. A management device 14 selectively drives the respective operation element execution devices 11a-13c which are arranged in parallel along procedures needed to array and incorporate the components and a selector 15 selectively transmits the functions of the specific operation elements, selectively driven by the management device 14, to the manipulator 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot control method for causing a robot manipulator to perform a certain series of work, and a control device used directly for the execution thereof.

[0002]

2. Description of the Related Art Generally, in order for a robot manipulator to perform a certain series of work, information such as the position and orientation of a work target such as a part is detected by a sensor, and based on the information obtained by this sensor, When controlling a robot manipulator, the following method is adopted.

FIG. 10 is a diagram for conceptually explaining a control method of a conventional robot manipulator.

As shown in FIG. 1, according to the conventional method, the manipulator 1 (hereinafter, simply referred to as "manipulator" refers to the "movable arm portion" of the robot manipulator) serves as an index for determining the position and posture of the robot manipulator. A sensor information processing device 3 that processes information from the sensor 2, a manipulator command generation device 4 that determines based on the information and generates a command for the manipulator 1, and a manipulator motion that controls the motion of the manipulator 1 based on the command. By sequentially configuring each of the work elements (functions) such as sequentially providing the control device 5 or the like, so to speak, a work element executing device is individually configured, and by consistently combining them, the required The robot manipulator (the whole structure is not shown) is controlled.

[0005]

In the control method of the robot manipulator described above, each work element execution device is
It is closely related to other work element execution devices, such as receiving information from the work element execution device of the previous stage and passing the information to the work element execution device of the subsequent stage one after another. When changed, the change must be made to all work element execution units that have a consistent relationship with them in order to maintain consistency and consistency. This means that it is necessary to change all the work element execution devices, for example, when changing a required series of works.

Further, in order to expand the function, an existing technique is constructed and introduced as a work element execution device, or the work element execution device previously used for another work is used for another work. If it is intended to be used for, it must be created to conform to the interface and protocol for exchanging information with other work element execution devices, and the creation of such a new work element execution device is There is a problem that it takes time and costs.

The main objects to be solved by the present invention are as follows. That is, a first object of the present invention is to provide a robot control method and apparatus capable of flexibly coping with a change in work to be executed by a robot manipulator.

A second object of the present invention is to provide a robot control method and apparatus capable of easily expanding the function to be given to the robot manipulator even by adding the existing elemental technology. .

[0009] Other objects of the present invention will become apparent from the description of the specification, drawings, and particularly from the claims.

[0010]

In order to solve the above-mentioned problems, the above-mentioned object is achieved by adopting the novel characteristic construction method and construction means enumerated below by the present invention.

The first feature of the method of the present invention is to select one or a plurality of work elements formed by dividing a series of works for each unit function of the manipulator in accordance with a procedure necessary for performing the series of works. Robot control method.

A second feature of the method of the present invention is a robot control method in which the plurality of work elements in the first feature of the method of the present invention maintain independence such that information does not interfere with each other. It is in.

A third feature of the method of the present invention is a robot control method in which the work element in the first or second feature of the method of the present invention is one or a plurality of work processes that form a unit function of the manipulator. It is in.

The fourth feature of the method of the present invention is that the working process in the third feature of the method of the present invention is moving, gripping,
It is in the robot control method, which is three types of arrangement.

The fifth feature of the method of the present invention is that the working process in the fourth feature of the method of the present invention is moving, gripping,
This is a robot control method that is repeatedly executed in the order of movement, placement, and movement.

A sixth feature of the method of the present invention is that one or a plurality of work required accuracies by which the work element in the first or second feature of the method of the present invention determines an operation level of a unit function of the manipulator. And a robot control method.

A seventh feature of the method of the present invention is that the work required precision in the sixth feature of the method of the present invention is the first level precision, or the second level with higher precision than the first level precision.
And the third level precision higher than the second level precision.

An eighth feature of the method of the present invention is that the work required precision in the seventh feature of the method of the present invention sequentially shifts to a first level precision, a second level precision and a third level precision. There is a robot control method.

A ninth feature of the method of the present invention is that the working element in the first or second feature of the method of the present invention comprises one or a plurality of work processes which form a unit function of a manipulator, and a unit of the manipulator. It is a robot control method which is divided for each one or a plurality of work required accuracies for determining an operation level of a function.

The tenth feature of the method of the present invention is that the work process and the work precision required in the ninth feature of the method of the present invention are three types of movement, gripping and placement, and the first level precision. A selective combination of a second level precision having a higher precision than the first level precision and a third level precision having a higher precision than the second level precision, one type each, is made. There is a robot control method.

An eleventh feature of the method of the present invention is that the work process and the work precision required in the tenth feature of the method of the present invention are repeatedly executed in the order of movement, gripping, movement, placement and movement, In the robot control method, the first level accuracy, the second level accuracy, and the third level accuracy are sequentially transferred for each work process.

A twelfth feature of the method of the present invention is that the first level precision in the seventh, eighth, tenth, or eleventh feature of the method of the present invention determines the required work precision by a non-contact sensor. The robot control method has an accuracy that can be satisfied by loop control.

A thirteenth feature of the method of the present invention is that the second level precision in the seventh, eighth, tenth, eleventh or twelfth feature of the method of the present invention is a work-necessary precision, which is a non-contact sensor. The robot control method has an accuracy that can be satisfied by closed-loop control by.

The fourteenth feature of the method of the present invention is the seventh, eighth, tenth, eleventh, twelfth or thirteenth of the method of the present invention.
The third level accuracy in the above feature is a robot control method in which the required work accuracy can be satisfied by the closed loop control by the contact sensor.

On the other hand, the first feature of the device of the present invention is that a series of work is divided for each unit function of the manipulator.
One or a plurality of work element execution devices that execute one or a plurality of work elements, and a management device that selectively drives the work element execution devices in accordance with the procedure required to perform the series of work. It is in the robot controller.

A second feature of the device of the present invention is that the work element executing device in the first feature of the device of the present invention moves the hand of the manipulator, and the hand of the manipulator. In the robot controller, there is a gripping work element execution device for gripping a work target object, and a placement work element execution device for positioning the work target object gripped by the hand of the manipulator at a required location. .

The third feature of the device of the present invention is that the work element execution device in the first or second feature of the device of the present invention determines the operation level of the unit function of the manipulator. An element execution device, a second level precision work element execution device having an operation level with higher precision than the first level precision work element execution device, and a higher precision than this second level precision work element execution device. And a third level precision work element execution device having a motion level, and a robot controller.

A fourth feature of the device of the present invention is that the work element executing device in the first, second or third feature of the device of the present invention can be selectively driven without exchanging information with each other. It is in a robot control device that is arranged in parallel.

The fifth feature of the device of the present invention resides in that the first to third level precision work element execution devices in the third feature of the device of the present invention are both robot control devices which are teaching playback devices. is there.

A sixth feature of the device of the present invention is that the teaching playback device in the fifth feature of the device of the present invention is replaced with a look and move device as the first level precision work element execution device. It is in the control unit.

The seventh feature of the device of the present invention is that the teaching playback device in the fifth or sixth feature of the device of the present invention is replaced with a visual servo device as the second level precision work element execution device. It is in the robot controller.

The eighth feature of the device of the present invention is that the teaching playback device in the fifth, sixth or seventh feature of the device of the present invention is force feedback as the third level precision work element execution device. It is in a robot control device that is replaced with a device.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION First, an outline including a configuration description of a robot manipulator to which the present invention is applied will be described, and then an example of an apparatus and an example of a method of the present invention will be sequentially described.

(Summary) First, when applying the present invention, as an example of a series of operations, a parts aligning operation and a parts assembling operation that are frequently performed in a manufacturing process of an industrial product are assumed.

That is, the part aligning work to be carried out here is one placed on the pallet A as shown in FIG. 1 (a diagram showing how the robot manipulator according to the present invention performs the part aligning work). Alternatively, it is a work of picking up a plurality of parts A ′ with the hand of the manipulator 1 and placing them again at a predetermined position on the pallet B.
As shown in FIG. 2 (a diagram showing how a robot manipulator to which the present invention is applied performs a component assembling work), the component assembling work is performed by manipulating one or a plurality of components A ′ placed on the pallet A. It is the work of picking it up with the hand of and assembling it at a predetermined position of the part B.

Then, the illustrated robot controller 10 is
As will be described in detail in an apparatus example and a method example described later, one or a plurality of work elements formed by dividing the above-described component alignment work and component assembly work for each unit function of the manipulator 1 are used to perform the work. It is configured to have a function of executing selectively according to a required procedure.

Here, in the case where the manipulator 1 considers its own unit function when the manipulator 1 carries out the above-mentioned parts aligning work and parts assembling work, that is, a minimum work element necessary and sufficient for achieving the required work. It can be said that the series of work can be divided into three types of work processes of moving, gripping, arranging or assembling (hereinafter, these two are represented by the word "arrangement"). The present invention incorporates means capable of individually executing these three types of work processes into the robot control device 10 (details will be described later).

In order to perform the above-mentioned work by the manipulator 1, the positioning accuracy of the manipulator 1 with respect to the work object, that is, the part A ', must be lowered within the allowable error range that can be achieved by the work. That is, it can be considered that the positioning accuracy of the manipulator 1 is gradually increased, and if the positioning accuracy is within the required accuracy of the operation, the execution of the operation can be achieved.

Therefore, each work element described above (each work process)
The required work accuracy for each of the following: ・ Level 1 accuracy: Accuracy that can be satisfied by open loop control by a non-contact sensor (allowable error of about 5 cm or more) ・ Level 2 accuracy: Satisfied by closed loop control by a non-contact sensor Precision that can be done (about 5 cm to 0.5 mm
Level 3 accuracy: Accuracy that can be satisfied by closed-loop control by a contact sensor (allowable error of approximately 0.5 mm or less) shall be divided into 3 levels.

(Apparatus Example) Next, an example of a robot controller configured to realize the above functions will be described with reference to the drawings. FIG. 3 is a diagram showing a configuration of an example of a robot control device according to an embodiment of the device of the present invention.

As shown in the figure, the robot control device 10 is a moving work element execution device 11 for moving the hand of the manipulator 1 based on the information from the sensor 2.
a (level 1 precision), and a gripping work element execution device 12a, 1 for gripping the part A ′ with the hand of the manipulator 1.
2b and 12c (level 1 precision, level 2 precision, and level 3 precision in this order) and the placement work element execution devices 13a, 13b, and 13c for placing the part A ′ gripped by the hand of the manipulator 1 at a required location. And (in order, level 1 precision, level 2 precision, level 3 precision), and further, in accordance with the procedure necessary for performing the above-described component alignment work and component assembly work, the above-described work element execution devices 11a to 13 in parallel.
management device 14 for selectively driving c, and this management device 1
A selector 15 for selectively transmitting to the manipulator 1 the function of a predetermined work element execution device selectively driven by
And is configured.

Although not shown in the drawings, a level 2 precision or level 3 precision moving work element execution device may be provided for moving the hand of the manipulator 1. In addition, each work element execution device 11a to 13c
Is configured to execute the assigned work element without exchanging information with any of the other work element execution devices 13a to 13c. Further, the management device 14 is configured so that the prepared work element execution devices 13a to 13c are activated in an order necessary and sufficient for performing the required work. That is, the management device 14 has no concern about the configuration of each work element execution device 13a to 13c, and recognizes only the existence of each work element execution device 13a to 13c to be activated.

Here, the work element execution devices for the above required work precisions are as follows: level 1 precision work element execution device: look and move device level 2 precision work element execution device: visual servo device level 3 Precision work element execution device: A force feedback device can be used, and a teaching playback device can be used as a work element execution device that executes work elements that do not need to further increase work accuracy.

The function of each of these devices is as described below. (1) Look and move device A feature point on the pallet is photographed by a camera mounted on the ceiling, the position and orientation of the pallet is calculated from the coordinate values of the feature point on the image, and the position to move the manipulator 1 , The posture, and the required position according to this result,
A device that controls the manipulator 1 to move to a posture.

(2) Visual Servo Device The feature point of the part A'is photographed by the camera attached to the hand of the manipulator 1, and the manipulator 1 is adjusted so that the feature point on the photographed image coincides with the target feature point. A device that feedback-controls the position and orientation of the robot.

(3) Force feedback device Based on force information obtained from a force sensor attached to the wrist of the manipulator 1 when parts contact with a pallet or when parts contact with each other, the position and orientation of the manipulator 1 can be determined. The device that controls.

(4) Teaching playback device A device for controlling the hand of the manipulator 1 to move along the trajectory that the hand of the manipulator 1 has previously taught.

(Example of Method) Next, an execution procedure of the example of the method according to the present embodiment applied to the above example of the apparatus will be described. FIG. 4 is a diagram for explaining an example of a robot control method according to an embodiment of the method of the present invention.

As shown in the figure, in this robot control method, the management device 14 first moves the manipulator 1 from the initial position to the position where the component A'is gripped. A series of work is started by activating the execution device 11a (if necessary, sequentially activating the level 2 precision and level 3 precision mobile work element execution devices) [ST1].

Next, in order for the manipulator 1 to actually grip the part A ', the management device 14 activates the level 1 precision gripping work element execution device 12a [ST2], and hereinafter, the level 2 precision gripping work. The element execution device 12b and the level 3 precision gripping work element execution device 12c are sequentially activated [ST3, ST4].

Next, in order to move the manipulator 1 to the arrangement position of the part A ', the management device 14 again activates the level 1 precision moving work element execution device 11a [ST5] (if necessary, level 2 order and level 3 accuracy mobile work element execution devices are activated in sequence).

Next, in order to move the manipulator 1 to the placement position of the part A ′ and actually place the part A ′,
The management device 14 activates the level 1 precision placement work element execution device 13a [ST6], and subsequently activates the level 2 precision placement work element execution device 13b and the level 3 precision placement work element execution device 13c. ST7, ST8].

Here, when there is no part A'to be arranged [ST9], the management device 14 again moves the level 1 to move the manipulator 1 to the end position.
Start the mobile work element execution device 11a with high accuracy [ST1
0] (If necessary, the level 2 precision and level 3 precision mobile work element execution devices are activated in sequence), and a series of work is completed.

On the other hand, when the part A'to be placed remains [ST9], the manipulator 1 is moved to the part A '.
In order to move it to the grip position, the management device 14 again activates the level 1 precision moving work element execution device 11a [ST11] (if necessary, level 2 precision and level 3 precision moving work element execution devices). Start in order).

[0055]

EXAMPLES Finally, five types of examples showing applications of the embodiments described above will be described with reference to the drawings.

(First Embodiment) -Refer to FIG. 5 (a diagram for explaining the first embodiment of the present invention) in which the pallets A and B and the component A'to be gripped are accurately positioned. ) In this case, the positioning accuracy of the manipulator 1 is considered to be within an allowable error range for work execution, and there is no need to particularly reduce the error. Device 11a [ST1, ST5, ST10-11],
Each gripping work element execution device 12a, 1 with level 1 to 3 accuracy
2b, 12c [ST2-4], level 1 to 3 precision placement work element execution devices 13a, 13b, 13c [ST6-
The teaching playback device may be used for all of [8].

(Second Embodiment) -Refer to FIG. 6 (drawing for explaining the second embodiment of the present invention) in which parts to be grasped are positioned with an accuracy of about 0.5 mm to 5 cm. ) In this case, the level 2 precision gripping work element execution device 12 in the first embodiment described above.
As shown in the figure, b [ST3] may be changed from the teaching playback device to the visual servo device.

(Third Embodiment) -Parts alignment work in which the pallet A is positioned with an accuracy of 5 cm or more (see FIG. 7 (a diagram for explaining a third embodiment of the present invention)) In this case, Level 1 precision gripping work element execution device 12a [ST2] in the second embodiment
Can be changed from a teaching playback device to a look and move device as shown in the figure.

(Fourth Embodiment) -Parts alignment work in which both pallet A and pallet B are positioned with an accuracy of 5 cm or more (see FIG. 8 (fourth embodiment of the present invention).
In this case, the level 1 precision placement work element execution device 13a in the above-described third embodiment is changed from the teaching playback device to the look and move device, and the level is also changed. The two-precision placement work element execution device 13b [ST7] may be changed from the teaching playback device to the visual servo device as shown in the drawing.

(Fifth Embodiment) -Parts assembling work in which both pallet A and pallet B are positioned with an accuracy of 5 cm or more (see FIG. 9 (a diagram for explaining the fifth embodiment of the present invention)) In this case, the level 3 precision placement work element execution device 13c [ST8] in the above-described fourth embodiment may be changed from the teaching playback device to the force feedback device as shown in the drawing.

[0061]

As described above, according to the present invention,
In order to make the robot manipulator execute a series of work, the series of work was decomposed into work elements corresponding to the smallest functional unit of a level that does not require the exchange of information with others, and each work element was handled. Since each work element execution device is selectively executed by using the management device, each work element execution device is configured without considering how other work element execution devices are configured. As a result, even if a part of the work element is changed, it is not necessary to change the other work elements, so that the robot manipulator can flexibly respond to the change of a series of works to be performed. It becomes possible to do. This means, for example, using a new sensor,
This means that it is not only useful when a work element execution device having a new function is added, but it can flexibly deal with partial correction of a series of works and diversion to another work.

Further, since there is no interface or protocol for exchanging information between the respective work element execution devices, it is inevitable to consider the problems caused by their existence. The existing technique can be configured as a work element execution device at low cost in a short period of time, and the function of the robot manipulator can be easily expanded.

[Brief description of drawings]

FIG. 1 is a diagram showing how a robot manipulator to which the present invention is applied performs parts alignment work.

FIG. 2 is a diagram showing how a robot manipulator to which the present invention is applied performs a component assembling work.

FIG. 3 is a diagram showing a configuration of an example of a robot control device according to an embodiment of the device of the present invention.

FIG. 4 is a diagram illustrating an example of a robot control method according to an embodiment of the method of the present invention.

FIG. 5 is a diagram for explaining the first embodiment of the present invention.

FIG. 6 is a diagram for explaining a second embodiment of the present invention.

FIG. 7 is a diagram for explaining a third embodiment of the present invention.

FIG. 8 is a diagram for explaining a fourth embodiment of the present invention.

FIG. 9 is a diagram for explaining a fifth embodiment of the invention.

FIG. 10 is a diagram for conceptually explaining a control method for a conventional robot manipulator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Manipulator 2 ... Sensor 10 ... Robot control device 11a ... Level 1 precision moving work element execution device 12a ... Level 1 precision gripping work element execution device 12b ... Level 2 precision gripping work element execution device 12c ... Level 3 precision Grasping work element execution device 13a ... Level 1 precision placement work element execution device 13b ... Level 2 precision placement work element execution device 13c ... Level 3 precision placement work element execution device 14 ... Management device 15 ... Selector

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[Procedure amendment]

[Submission date] May 23, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoyoshi Kanamaru 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Hiroyuki Ogata 3-19-3 Nishishinjuku, Shinjuku-ku, Tokyo No. 2 within Nippon Telegraph and Telephone Corporation

Claims (22)

[Claims] 1. A one or a plurality of work elements obtained by dividing a series of works for each unit function of a manipulator, and selectively executing the work elements according to a procedure necessary for performing the series of works. Robot control method. 2. The robot control method according to claim 1, wherein the plurality of work elements maintain independence such as exchange of information that does not interfere with each other. 3. The robot control method according to claim 1, wherein the work element is one or a plurality of work processes that form a unit function of the manipulator. 4. The robot control method according to claim 3, wherein the work process includes three types of movement, gripping, and placement. 5. The robot control method according to claim 4, wherein the work process is repeatedly executed in the order of movement, gripping, movement, placement, and movement. 6. The robot control method according to claim 1, wherein the work element has one or a plurality of work required accuracies that determine an operation level of a unit function of the manipulator. 7. The required work precision includes a first level precision, a second level precision higher than the first level precision, and a third level precision higher than the second level precision. 7. The robot control method according to claim 6, characterized in that 8. The robot control method according to claim 7, wherein the work required accuracy sequentially shifts to a first level accuracy, a second level accuracy, and a third level accuracy. 9. The work element is obtained by dividing one or a plurality of work processes forming a unit function of the manipulator into one or a plurality of work required precisions for determining an operation level of the unit function of the manipulator. The robot control method according to claim 1 or 2, wherein: 10. The work process and the work required accuracy are three types of movement, gripping and placement, a first level accuracy, a second level accuracy higher than the first level accuracy, and a second level accuracy. 10. The robot control method according to claim 9, wherein each of the three types of third level precision having higher precision than the second level precision is selectively combined one by one. 11. The work process and the work required accuracy are repeatedly executed in the order of movement, gripping, movement, placement, and movement, and a first level precision, a second level precision, and a third level precision are obtained for each work process. The robot control method according to claim 10, wherein the level accuracy is sequentially shifted. 12. The first level accuracy is an accuracy with which the work required accuracy can be satisfied by open loop control by a non-contact sensor, The method according to claim 7, 8, 10 or 11. Robot control method. 13. The second level accuracy is an accuracy with which a required work accuracy can be satisfied by closed loop control by a non-contact sensor, according to claim 7, 8, 10, 11 or 12. Robot control method. 14. The third level accuracy is an accuracy with which the work required accuracy can be satisfied by closed loop control by a contact sensor, according to claim 7, 8, 10, 11, 12 or 13. The described robot control method. 15. One or a plurality of work element execution devices for executing one or a plurality of work elements, which are obtained by dividing a series of works for each unit function of a manipulator, and a procedure necessary for performing the series of works. A robot control device, comprising: a management device that selectively drives the work element execution device according to. 16. The work element execution device, a moving work element execution device for moving a hand of the manipulator, a gripping work element execution device for gripping a work target with the hand of the manipulator, and the manipulator. 16. The robot control device according to claim 15, further comprising: an arrangement work element execution device for arranging the work target object grasped by the hand of the operator at a desired position. 17. The work element execution device includes a first level precision work element execution device that determines an operation level of a unit function of the manipulator, and an operation with higher precision than the first level precision work element execution device. A second level precision work element execution device having a level, and a third level precision work element execution device having an operation level with higher accuracy than the second level precision work element execution device. The robot controller according to claim 15 or 16. 18. The robot controller according to claim 15, 16 or 17, wherein the work element execution devices are arranged in parallel so that they can be selectively driven without exchanging information with each other. 19. The robot controller according to claim 17, wherein each of the first to third level precision work element execution devices is a teaching playback device. 20. The robot controller according to claim 19, wherein the teaching playback device is replaced with a look and move device as the first level precision work element execution device. 21. The robot controller according to claim 19, wherein the teaching playback device is replaced with a visual servo device as the second level precision work element execution device. 22. The robot controller according to claim 19, 20 or 21, wherein the teaching playback device is replaced with a force feedback device as the third level precision work element execution device.