JP3192766B2 - manipulator - Google Patents

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 a predetermined assembling operation and a maintenance operation.

[0002]

2. Description of the Related Art As is well known, in order to cause a manipulator to perform a predetermined assembling operation or a maintenance operation by a gripper or the like at the end of an arm thereof, the gripper or the like is moved into a work area, and the manipulator is required to perform an operation. Relative position,
A predetermined operation may be performed after confirming the shape.

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

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

[0005] In FIG. 8, reference numeral 1 denotes a visual sensor unit;
The light source 3 is arranged on the upper side. Reference numeral 4 denotes a slit for forming slit light from the light emitted from the light source 3. Reference numeral 5 denotes a swingably provided mirror. The slit light reflected by the swinging mirror 5 is, for example, a rectangular parallelepiped 6 of an object. Circular hole 7 as the target part
a and 7b. 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 reflected light being processed is processed by a signal processing unit (not shown). Recognition of the distance and the shape to the hole 7a has been performed.

If it is determined that the circular hole 7a of the rectangular parallelepiped 6 is a predetermined one, a predetermined operation for the circular hole 7a is performed based on the position data and the distance data from the obtained image signal. Done by

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

Further, regarding the circular hole 7b which is the target portion of the rectangular parallelepiped 6 of the same object, a blind spot area is generated from the positional relationship between the rectangular parallelepiped 6, the mirror 5 and the image sensor 8, and the blind spot area is included in the blind spot area. The slit light is not projected and cannot be captured by the image sensor 8.

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

Under such circumstances, there is no need to provide a drive unit separate from the manipulator to move the visual sensor unit 1 or to provide a plurality of visual sensor units in response to the occurrence of the blind spot area. In addition, it does not require complicated processing of image signals and the like, and easily obtains data on the shape, position, distance, and the like of the circular holes 7a and 7b, which are target portions, performs control operations in a short time, and executes a predetermined operation by the manipulator. It is required to be done.

[0011]

As described above, in the case of using the conventional visual sensor unit, it is necessary to cope with the occurrence of a blind spot area, and the position and distance of the object to be processed by processing the image signal of the light projection pattern. And so on, so that processing takes time. The present invention has been made in view of such a situation, and the object thereof is to make it possible to obtain the position and the distance of the target portion in a short time without generating a blind spot area when obtaining the position and the distance. Another object of the present invention is to provide a manipulator that has a high performance.

[0012]

A manipulator according to the present invention performs an operation on a circular target portion provided on an object.
A working end, and the object provided at the working end.
Distance sensor for detecting the distance of
Scanning direction, and the working end is in the required posture.
A driving device that changes the posture so that the distance sensor
A scanning operation in a first direction including the target portion;
And two edges are detected in the first direction.
Scanning operation in the second direction intersecting with
To detect two edges, and that the working end is
Controls the drive unit so that it has the required attitude with respect to the target
A drive control unit that performs scanning in the first direction.
Calculate the midpoint between the two issued edges and
The other two detected by the scanning operation in the second direction passing through
To calculate the center position of the target part
And the scanning operation in the first and second directions
Calculation for calculating the inclination of the working end with respect to the object
And a unit based on the inclination calculated by the arithmetic unit.
The working end of the object is positioned at the center of the object.
It is especially important to adjust the posture so that the required posture is obtained directly above.
And the distance provided at the working end.
Characterized in that there is one separation sensor,
In addition, a force sensor is installed on the working end together with the distance sensor.
To the target part using the load signal of the force sensor.
The position and posture of the working end are adjusted .

[0013]

In the manipulator constructed as described above, a distance sensor is provided at the working end, and the distance sensor includes the target part.
Scanning in a first direction and a second direction orthogonal to the first direction
Operate to adjust the center position of the target part and the target object at the working end.
The inclination of the target object and the working end.
The distance sensor performs a scan operation in at least one direction on the target portion to calculate the position and distance of the working end portion with respect to the target portion. Along with the scanning direction, the distance between the working end and the opposing target portion is continuously obtained by the distance sensor, and which position corresponds to the obtained distance is determined by the distance sensor by the scanning operation. By knowing the amount of movement, it becomes clear within a short time. Based on the information on the determined position and distance, it is determined whether the target portion is a predetermined target portion, and the work by the working end portion is performed. At this time, since the distance sensor is provided at the working end and always faces the target portion, no blind spot area is generated when calculating the position and distance of the target portion,
In addition, since the position and the distance are calculated from the signal from the distance sensor and the movement amount of the distance sensor, the position and the 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 One 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 a control operation in the control device, FIG. 4 is a diagram for explaining a scan operation, and FIG. 6 is an output diagram of x-direction position-distance information during an x-direction scan operation, FIG. 6 is a y-direction position-distance information output diagram during a y-direction scan operation, and FIG. 7 is a diagram for explaining an axis alignment operation. It is.

In FIG. 1 and FIG.
Numeral 1 is provided with an arm 13 and a joint 14 so as to have six degrees of freedom on a support base 12. The arms 13a, 13b,..., 13f of the arm 13 are connected to the joints 14a, 14b,. The position and orientation can be changed by rotating around each of the rotation axes indicated by chain lines. Thereby, the arm 13a at the forefront can take a required position and orientation.

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

In the control device 15, a control signal is output from the drive control unit 16 in accordance with the conditions set in the setting unit 21,
As a result, the driving device 17 is operated and the arms 13a, 13
.., 13f make a predetermined movement. The arm 13a at the foremost end obtained from the control signals of the arms 13a, 13b,.
9, the movement signal of the movement direction and the movement distance, and the distance sensor 1
9 and a distance signal corresponding to the distance between the object and the opposing object are input to the arithmetic unit 22, and the position of the gripper 18 or the object held by the gripper 18 and the distance between the object and the object facing the gripper 18 are calculated. It is supposed to be.

The operation result of the operation unit 22 is also input to the drive control unit 16 according to the set conditions, so that the movement of the driving device 17 corresponding to the operation result can be controlled. It has become. The position and distance at a plurality of locations are calculated by changing the measurement portion and direction as necessary, for example, when the distance sensor 19 must accurately recognize that the distance sensor 19 is facing.

Further, the operation result of the operation unit 22 is compared and compared.
The data is also input to the determination unit 23, and the setting unit 2
A comparison with the value set to 1 and a matching status, and the like, and a determination as to whether the opposing object is a predetermined object are also made.

On the other hand, a 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 vehicle satisfies the set condition, for example, to reduce the load.

Next, the operation of the above-configured device will be described with reference to FIGS. Here, as a predetermined operation, for example, an operation of inserting the columnar body 26 into the circular holes 25a and 25b of the target portion formed in the rectangular parallelepiped 24 as the target object will be described.

First, the manipulator 1 is attached to the gripper 18.
The cylindrical body 26 is gripped in accordance with the work content to be executed by the user 1. And the arm 13a at the foremost part is
5a is moved so as to be located in a predetermined work area where the distance sensor 19 can detect the distance 5a.

[0023] Then, in step S1 shown in FIG. 3, the coordinate system H of the arm tip, which is set in consideration of the gripper 18 and the distance sensor 19 is offset (FIG. 1) is that x _H The arm 13a at the extreme end is positioned so as to include the circular hole 25a at the target portion in the direction, and the arm 13a at the extreme end is moved in the _xH direction of the coordinate system H.

In step S2, the rectangular parallelepiped 2 is formed while catching the circular hole 25a of the target portion with the detection axis of the distance sensor 19.
The distance between the 4 measured by the measurement operation of the x _H direction with the wrist posture constant of the manipulator 11, the drive control unit 1
6 based on each signal from the distance sensor 19
2, the distance sensor 19 as shown in FIG.
Is detected.

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

Further, in step S3, the midpoint C between the points A and B is calculated by the calculating section 22.

In step S4, the drive unit 17 is driven by the drive control unit 16 based on the calculation result, and the arm 13a
Is moved so that the detection axis of the distance sensor 19 passes through the middle point C.

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

[0029] Then, in step S6, measure the distance of a rectangular parallelepiped 24, the measurement operation of the y _H direction with the wrist posture constant of the manipulator 11, based on the respective signals from the drive control unit 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, a point D at which the distance information increases and a point E at which the distance information decreases are identified from the output result. These points D,
E is the counterpart to the y _H-direction edge of the circular hole 25a of the target portion.

Further, at step S7, the arithmetic unit 22 calculates the midpoint F between the points D and E.

In step S8, the drive unit 17 is driven by the drive control unit 16 based on the calculation result to
3a is moved so that the detection axis of the distance sensor 19 passes through the midpoint F.

In step S9, the position of the arm tip at this time is set as a point P, and the coordinate system I is set at the point P. And relative to the coordinate system I in the calculating portion 22, using the x _H direction and the y _H-direction distance information of the scan operation of the coordinate system H, the cuboid 24 circular hole 25a is bored x _I, y _I , z _I
Is calculated by the following equation. In the case where each or one of the distance information obtained x _H direction and the y _H direction scanning operation, the circular hole 25a from the equation of the upper surface G of the rectangular parallelepiped 24, which is calculated not specified, further measures a scan operation The comparison is performed by changing the part and direction, and the comparison with the set by the comparison / judgment unit 23 and the matching status are determined.

Subsequently, in step S10, a point Q having a distance L is calculated based on 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. The z _J-axis to the point Q to set the coordinate system J to match a line perpendicular to the street top G the point F.

Next, in step S11, the drive unit 1 is controlled by the drive control unit 16 so as to move from the point P to the point Q while taking into account the wrist posture of the arm 13a at the forefront.
7 is operated so that the coordinate system H at the tip of the arm coincides with the coordinate system J. This z _J-axis of the central axis and the coordinate system J the cylindrical body 26 which is gripped by the gripper 18 is matched.

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

Using the preset forces Fa _X , Fa _Y in the x _J and y _J directions and the viscous damping coefficients C _X , C _Y , the tip speed V _i of the arm 13a is determined as F _i > F a _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,
.., 14f are calculated by the calculation unit 22, and the drive control unit 16 controls the driving device 17 based on the calculation result, so that the driving unit 17 controls the driving speed of the driving device 17 to the circular hole 25a of the cylindrical body 26 gripped by the gripper 18 of the arm 13a. Perform the insertion.

On the other hand, for the operation of inserting the cylindrical body 26 into the circular hole 25b of the target portion drilled in the rectangular parallelepiped 24 as the target, the rectangular parallelepiped 24 as the target and the manipulator 1
.., 13f of the manipulator 11 while changing the position of each arm 13a, 13b,..., 13f of the manipulator 11. The same operation as for the circular hole 25a may be performed so as to catch the hole 25b.

As described above, in this embodiment, the gripper 18 for performing the operation on the arm 13a at the distal end of the manipulator 11 is used.
In addition, a distance sensor 19 for measuring the distance to the target part of the work is provided, and the manipulator 11 is operated to scan in a coordinate system H set at the tip of the arm. Round hole 2
The position of 5a can be known, and the deviation of the inclination between the central axis of the circular hole 25a and the central axis of the cylindrical body 26 held by the gripper 18 can be known.

Then, by correcting the position of the cylindrical body 26 with respect to the hole 25a on the basis of the clarified position, displacement, and the like, the operation of inserting the cylindrical body 26 into the hole 25a can be performed smoothly. In addition, cylindrical body 2 which is performed during insertion work
6 and the circular hole 25a can be checked for relative positions and deviations.
Since complicated processing such as processing of image signals is not required, processing can be executed easily and in a short time.

For the hole 25b having a different surface from the hole 25a, the gripper 18 for performing the operation provided on the arm 13a is arranged near the hole 25b, so that the distance sensor is naturally provided. 19 is also arranged in the vicinity thereof, and no blind spot area is generated.
After a short time position check or the like as in the case of a, the insertion work of the cylindrical body 26 can be executed smoothly.

In the above-described embodiment, the scanning operation is performed in a state where the wrist posture of the manipulator 11 is constant. However, the scanning operation may be changed, and the cylindrical body 26 is inserted into the circular hole 25a of the target portion. Although a simple shape is described as an example, the present invention may be applied to an operation targeting a more complicated shape, and the number of scanning operations can be reduced by providing a plurality of distance sensors 19 on the arm 13a at the distal end. For example, the present invention may be appropriately modified and implemented without departing from the gist.

[0043]

As is apparent from the above description, the present invention provides a distance sensor at the working end and causes the distance sensor to perform a scanning operation in at least one direction with respect to the target portion. With the configuration that calculates the position and the distance to the target portion, the blind spot region does not occur when calculating the position and the distance of the target portion,
The effect is obtained in a short time without complicated signal processing, and an effect that the work can be performed is obtained.

[Brief description of the drawings]

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

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

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

FIG. 4 is a diagram for explaining a scanning 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 an output diagram of position-distance information in the y-direction during the above-described y-direction scanning operation.

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 according to the related art.

[Explanation of symbols]

 DESCRIPTION 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

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B25J 13/08 B25J 9/10 G01B 11/00 G01B 11/26

Claims (3)

(57) [Claims] 1. A method according to claim 1, wherein the object is a circular object provided on the object.
Detecting the distance between a working end for performing the work and the object provided at the working end.
Scanning a distance sensor and the working end in a predetermined direction;
A drive device that changes the position of the working end to the required position
If, scan the distance sensor in a first direction including the target portion
To detect two edges of the target portion,
The scanning operation is performed in a second direction orthogonal to the first direction.
Detecting the other two edges of the target portion,
So that the working end has a required posture with respect to the object.
A drive control unit for controlling the drive device, and two edges detected by the scan operation in the first direction
Calculating the midpoint between and the second direction passing through the midpoint
The midpoint between the other two edges detected by the scan operation
Calculating the center position of the target part, and
And scanning operation in the second direction by the scanning operation in the working end.
A calculating unit for calculating a tilt with respect to the object, wherein the calculating unit calculates a tilt with respect to the target based on the tilt calculated by the calculating unit.
The working end is required just above the center of the target part.
Mani characterized by performing posture adjustment so that
Purator. And a distance sensor provided at the working end.
2. The manipulator according to claim 1, wherein
Ta. 3. A haptic sensor together with a distance sensor is provided at the working end.
The target portion is provided by using a load signal of the force sensor.
Adjusting the position and orientation of the working end with respect to
The manipulator according to claim 1 or 2, wherein: