JPH0679672A - Manipulator - Google Patents

Abstract

PURPOSE:To provide a manipulator which can quickly determine the position and distance of the part to be processed. CONSTITUTION:A distance sensor 19 is installed on an arm 13a having a gripper 18 and moved for scanning a rectangular paralleopiped 24 as object to be processed, and thereby the position and distance of the gripper 18 relative to the parallelopiped 24 are calculated. so that the confronting distance to the parallelopiped 24 can be sensed continuously by the distance sensor 19 in the scanning direction, and judging which position the obtained distance corresponds to, can easily and quickly be made from the motion control signal of the distance sensor 19 to make scanning motions. On the basis of the result from judgement, a column 26 held by the gripper 18 can be inserted accurately in a circular hole 25a provided in the parallelopiped 24, and there is no risk of generating any dead angle region for the part to be processed because the distance sensor 19 is installed on the arm 13a and confronting the parallelopiped 24 at all times.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manipulator for performing predetermined assembly work and maintenance work.

[0002]

2. Description of the Related Art As is well known, in order to cause a manipulator to perform a predetermined assembling work or maintenance work by a gripper or the like at the tip of its arm, the manipulator is moved into a work area to be operated. The relative position,
A predetermined work may be performed after confirming the shape.

In such a case, the information such as the relative positional relationship between the manipulator, particularly the gripper and the target object, and the shape of the target object is obtained by processing the image signal obtained from the visual sensor. ing.

A conventional technique will be described below with reference to FIG. FIG. 8 is a perspective view of the visual sensor unit.

In FIG. 8, reference numeral 1 is a visual sensor unit which is a base 2
The light source 3 is arranged above. Reference numeral 4 is a slit for forming slit light from the light emitted from the light source 3, 5 is a mirror provided so as to be swingable, and the slit light reflected by the swinging mirror 5 is, for example, a rectangular parallelepiped 6 of an object. Round hole 7 which is the target part
It is projected on a and 7b. Further, the light reflected by the rectangular parallelepiped 6 is incident on the image sensor 8, and the image signal of the light projection pattern from the image sensor 8 obtained by the incident reflected light is processed by a signal processing unit (not shown), and the circle of the rectangular parallelepiped 6 is processed. The distance to the hole 7a and the shape have been recognized.

When it is determined that the circular hole 7a of the rectangular parallelepiped 6 is a predetermined one, the manipulator (not shown) performs a predetermined work on the circular hole 7a based on the position data and the distance data from the obtained image signal. Done by

However, in order to obtain the data such as the shape, position and distance of the circular hole 7a which is the target portion of the predetermined work, the entire rectangular parallelepiped 6 of the target object is scanned by the slit light reflected by the swinging mirror 5. All the light projection patterns are required. Then, the image signal of the light projection pattern is processed by the signal processing unit to obtain the shape, position, distance and the like of the circular hole 7a of the rectangular parallelepiped 6.
Since it is a complicated image signal processing, it takes a very long time.

Further, with respect to the circular hole 7b, which is the object portion of the rectangular parallelepiped 6 of the same object, a blind spot region is generated due to the positional relationship between the rectangular parallelepiped 6 and the mirror 5 and the image sensor 8. The slit light is not projected and cannot be captured by the image sensor 8.

For this reason, the slit light is projected on the circular hole 7b, and the visual sensor 1 is controlled and moved separately from the operation of the manipulator so that the reflected light has a positional relationship that can be captured by the image sensor 8. Alternatively, by using another visual sensor unit, the same predetermined work as in the circular hole 7a by the manipulator is performed on the circular hole 7b.

From such a situation, it is not necessary to provide a drive unit other than the manipulator in the visual sensor unit 1 to move the visual sensor unit 1 in response to the occurrence of a blind spot, or to provide a plurality of visual sensor units. Further, it is possible to easily obtain data such as the shape and position of the circular holes 7a and 7b, which are the target portions, the distance, etc. without performing complicated image signal processing, and control the operation in a short time to execute a predetermined work by the manipulator. Required to be done.

[0011]

As described above, in the conventional visual sensor unit, it is necessary to deal with the occurrence of the blind spot area, and the position and distance of the target subject by processing the image signal of the light projection pattern. It takes time to process because it asks. The present invention has been made in view of such a situation, and its object is to obtain the position and distance of the target portion in a short time without generating a blind spot area. It is to provide the manipulator which was made.

[0012]

A manipulator of the present invention is a manipulator configured to perform work on a predetermined target portion by a working end of an arm having a plurality of degrees of freedom, and a distance sensor is provided at the working end. The position and distance of the working end with respect to the target portion are calculated by causing the distance sensor to perform a scanning operation in at least one direction on the target portion.

[0013]

In the manipulator constructed as described above, a distance sensor is provided at the working end, and the distance sensor is caused to perform a scanning operation in at least one direction with respect to the position of the working end with respect to the target. Since the distance is calculated, the distance between the working end and the facing target portion is continuously obtained by the distance sensor along the scanning direction by performing the scanning operation. Whether it corresponds to the position can be determined within a short time by knowing the movement amount of the distance sensor due to the scanning operation. Based on the information on the determined position and distance, it is determined whether or not the target portion is a predetermined target portion, and the work by the work end portion is executed. At this time, since the distance sensor is provided at the working end and always faces the target portion, a blind spot region does not occur when determining the position and distance of the target portion, and the signal from the distance sensor and the distance sensor Since it is calculated from the movement amount, the position and distance can be obtained in a short time without complicated signal processing, and the work can be performed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 is a perspective view of a manipulator, FIG. 2 is a block diagram of a control device, FIG. 3 is a sequence of control operations in the control device, FIG. 4 is a diagram for explaining a scan operation, and FIG. 6 is an x-direction position-distance information output diagram at the time of x-direction scanning operation, FIG. 6 is a y-direction position-distance information output diagram at the time of y-direction scanning operation, and FIG. 7 is a diagram for explaining the axis alignment operation. Is.

In FIG. 1 and FIG. 2, the manipulator 1
1 has an arm portion 13 and a joint portion 14 on a support base 12 so as to have six degrees of freedom. Each of the arms 13a, 13b, ..., 13f of the arm unit 13 has one joint 14a, 14b, ..., 14f of the joint unit 14 in the figure by the drive unit 17 controlled by the drive control unit 16 of the control unit 15. The position and orientation can be changed by rotating about each rotation axis indicated by a chain line. This allows the arm 13a at the most distal end to take a desired position / posture.

Further, a gripper 18 is provided on the most distal arm 13a so that a predetermined work can be performed, and a distance sensor 19 is provided on the most distal arm 13a.
And a force sensor 20 are attached. The distance sensor 19 outputs a distance signal corresponding to the distance between the distance sensor 19 and the facing sensor as an input signal of the control device 15.

In the control device 15, the drive control unit 16 outputs a control signal according to the condition set in the setting unit 21,
As a result, the drive device 17 operates and each arm 13a, 13
b, ..., 13f perform predetermined movements. The arm 13a at the most distal end obtained from the control signals of the arms 13a, 13b, ...
9, the movement signal of the movement direction and the movement distance of 9, and the distance sensor 1
The distance signal corresponding to the distance from the object 9 from the object is input to the calculation unit 22, and the position of the gripper 18 or the object held by the gripper 18 and the distance to the object facing the gripper 18 are calculated. It is supposed to be done.

The calculation result of the calculation unit 22 is also input to the drive control unit 16 according to the set conditions, and the movement of the drive unit 17 corresponding to the calculation result can be controlled. It is like this. It should be noted that the position and distance at a plurality of locations are calculated by changing the measurement portion and direction as necessary, for example, the distance sensor 19 must be recognized with high accuracy.

Further, the calculation results in the calculation unit 22 are compared and
It is also input to the judgment unit 23, and the setting unit 2
The comparison with the value set to 1, the coincidence status, and the like, and whether or not the opposing object is a predetermined target are also determined.

On the other hand, the load signal from the force sensor 20 is also input to the arithmetic unit 22.
The drive device 17 is controlled by the drive control unit 16 so that the load acting on the load satisfies the set condition, for example, the load is reduced.

Next, the operation of the one configured as above will be described with reference to FIGS. Here, as a predetermined work, for example, a work of inserting the cylindrical body 26 into the circular holes 25a and 25b of the target portion formed in the rectangular parallelepiped 24 which is the target will be described.

First, the manipulator 1 is attached to the gripper 18.
The columnar body 26 is gripped according to the content of the work to be performed by 1. And the arm 13a at the most distal end is connected to the circular hole 2 of the target portion.
5a is moved so as to be located within a predetermined work area that can be sensed by the distance sensor 19.

Then, in step S1 shown in FIG. 3, the coordinate system H of the arm tip (shown in FIG. 1) set in consideration of the offset between the gripper 18 and the distance sensor 19 is x _H. The arm 13a at the most distal portion is positioned so as to include the circular hole 25a of the target portion in the direction, and the arm 13a at the most distal portion is moved in the x _H direction of the coordinate system H.

In step S2, the rectangular parallelepiped 2 is formed while the circular axis 25a of the target portion is captured by the detection axis of the distance sensor 19.
The distance between the drive controller 1 and the manipulator 11 is measured by measuring the distance from the manipulator 11 in the x _H direction while keeping the wrist posture constant.
6 and the calculation unit 2 based on each signal from the distance sensor 19.
As the calculation result of 2, the distance sensor 19 as shown in FIG.
The distance information at is detected.

From the output result, the point A where the distance information increases and the point B where the distance information decreases are identified. These points A, B
Is x _H of the circular hole 25a of the target portion formed in the rectangular parallelepiped 24.
It corresponds to the edge of the direction.

Further, in step S3, the midpoint C of the points A and B is calculated by the calculation unit 22.

In step S4, the drive control unit 16 drives the drive unit 17 to drive the arm 13a based on the calculation result.
Is moved so that the detection axis of the distance sensor 19 passes through the midpoint C.

Then, in step S5, the arm 13a is moved so that the detection axis of the distance sensor 19 moves in the y _H direction of the coordinate system H including the midpoint C.

Next, in step S6, the distance from the rectangular parallelepiped 24 is measured, and by the measurement operation in the y _H direction in which the wrist posture of the manipulator 11 is kept constant, based on the respective signals from the drive control section 16 and the distance sensor 19. As the calculation result of the calculation unit 22, the distance information from the distance sensor 19 as shown in FIG. 6 is detected. Then, from the output result, the point D where the distance information increases and the point E where the distance information decreases are identified. These points D,
E corresponds to the edge in the y _H direction of the circular hole 25a of the target portion.

Further, in step S7, the midpoint F of the points D and E is calculated by the arithmetic unit 22.

In step S8, the drive controller 17 drives the drive unit 17 based on the calculation result to drive the arm 1
3a is moved so that the detection axis of the distance sensor 19 passes through the midpoint F.

In step S9, the arm tip position at this time is set to point P, and the coordinate system I is set to point P. Then, with reference to the coordinate system I in the calculation unit 22, using the distance information at the time of the scanning operation in the x _H direction and the y _H direction in the coordinate system H, x _{I of} the rectangular parallelepiped 24 having the circular hole 25a, y _I , z _I
Calculate the equation for the upper surface G by When the circular hole 25a is not specified from the distance information in the x _H direction and the y _H direction obtained by one scanning operation or the calculated equation of the upper surface G of the rectangular parallelepiped 24, the scanning operation is further measured. The comparison / judgment unit 23 makes a comparison with the one set by the comparison / judgment unit 23 and judges the coincidence status.

Then, in step S10, a point Q having a distance L is calculated on the basis of the upper surface G in the direction in which the circular hole 25a is formed through the point F, that is, on a line perpendicular to the upper surface G. Then, the coordinate system J is set so that the z _J axis passes through the point F and is perpendicular to the upper surface G at the point Q.

Next, in step S11, the drive unit 1 is controlled while being controlled by the drive control unit 16 so as to move from the point P to the point Q so as to consider the wrist posture of the most advanced arm 13a.
7 is operated so that the coordinate system H of the arm tip coincides with the coordinate system J. As a result, the central axis of the cylindrical body 26 held by the gripper 18 and the z _J axis of the coordinate system J coincide.

After this, in step S12, z
_The arm 13a is driven in the negative direction of the _J- axis, that is, in the direction of approaching the upper surface G of the rectangular parallelepiped 24, and the circular hole 25a of the cylindrical body 26 is driven.
To insert into. When inserting, the cylinder 26 and the circular hole 25
a load F _X in the x _J direction and the y _J direction acting between a and
F _Y is detected by the force sensor 20 and the detected value is input to the calculation unit 22.

[0036] Then, a preset x _J-direction and y _J direction setting force Fa _X, Fa _Y and viscous damping coefficient C _X, using a C _Y, the tip speed _{V i} of the arm 13a, _{F i>} Fa i when, when the _{V i = C i (F i} -Fa i) F i ≦ Fa i is determined by _V i = 0. Here, i is x or y.

Using this value, each joint 14a, 14b,
The operating speed of 14f is calculated by the calculation unit 22, and the drive control unit 16 controls the drive unit 17 based on the calculation result to move the circular hole 25a of the cylindrical body 26 held by the gripper 18 of the arm 13a into the circular hole 25a. Insert.

On the other hand, regarding the work of inserting the cylindrical body 26 into the circular hole 25b of the target portion formed in the rectangular parallelepiped 24 which is the object, the rectangular parallelepiped 24 which is the object and the manipulator 1 are inserted.
, 13f of the manipulator 11 is changed while the position of the support base 12 of No. 1 is kept unchanged, and the distance sensor 19 provided on the arm 13a at the tip end of the manipulator 11 causes a circular hole of the target portion. The same operation as for the circular hole 25a may be performed so as to catch 25b.

As described above, in this embodiment, the gripper 18 for working the arm 13a at the tip of the manipulator 11 is used.
Along with this, a distance sensor 19 for measuring the distance to the target portion of the work is provided, and by scanning the manipulator 11 with the coordinate system H set at the tip of the arm, the change in the value obtained by the distance sensor 19 causes the object to change. Circular hole 2
It is possible to know the position of 5a and the deviation of the inclination between the central axis of the circular hole 25a and the central axis of the cylindrical body 26 gripped by the gripper 18.

Then, by correcting the position of the cylindrical body 26 with respect to the circular hole 25a on the basis of these clarified positions and deviations, the work of inserting the cylindrical body 26 into the circular hole 25a can be carried out smoothly. In addition, the cylindrical body 2 that is performed during the insertion work
6 and the confirmation of the relative position between the circular hole 25a,
Since complicated processing such as image signal processing is not required, the processing can be executed easily and in a short time.

For the circular hole 25b having a surface different from that of the circular hole 25a, the gripper 18 for performing the work provided on the arm 13a is arranged in the vicinity of the circular hole 25b, so that the distance sensor is automatically operated. 19 is also arranged in the vicinity of the circular hole 25, and a blind spot region does not occur.
Similar to the case of a, after the position confirmation for a short time and the like, the insertion work of the cylindrical body 26 can be smoothly executed.

In the above embodiment, the scanning operation is performed while the wrist posture of the manipulator 11 is constant, but it may be changed, and the cylindrical body 26 is inserted into the circular hole 25a of the target portion. However, the number of scan operations can be reduced by providing a plurality of distance sensors 19 on the arm 13a at the distal end. It may be carried out by appropriately changing it within a range not departing from the gist.

[0043]

As is apparent from the above description, according to the present invention, the working end portion is provided with the distance sensor, and the distance sensor is caused to scan the target portion in at least one direction. With the configuration that calculates the position and distance to the target portion, no blind spot region occurs when calculating the position and distance of the target portion,
The effect is obtained in a short time without complicated signal processing, and the work can be performed.

[Brief description of drawings]

FIG. 1 is a perspective view showing a manipulator according to an embodiment of the present invention.

FIG. 2 is a block diagram of a control device in the above.

FIG. 3 is a sequence of control operations in the control device described above.

FIG. 4 is a diagram for explaining a scan operation in the above.

FIG. 5 is an x-direction position-distance information output diagram during the x-direction scanning operation described above.

FIG. 6 is a y-direction position-distance information output diagram during the y-direction scanning operation described above.

FIG. 7 is a diagram for explaining the axis alignment operation in the above.

FIG. 8 is a perspective view of a visual sensor unit in the related art.

[Explanation of symbols]

 13 ... Arm part 13a ... Arm 14 ... Joint part 15 ... Control device 18 ... Gripper 19 ... Distance sensor 24 ... Rectangular parallelepiped 25a, 25b ... Circular hole 26 ... Cylindrical body

Claims (1)

[Claims] 1. A manipulator configured to perform a work on a predetermined target portion by a work end portion of an arm having a plurality of degrees of freedom, wherein a distance sensor is provided at the work end portion, and the distance sensor is attached to the target portion. A manipulator, wherein a position and a distance of the working end portion with respect to the target portion are calculated by performing a scanning operation in at least one direction.