JP3160443B2 - Non-contact point teaching device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact point teaching device applied to a robot manipulator.

[0002]

2. Description of the Related Art In the field of industrial robots, teaching devices such as teaching boxes (including joysticks) and controllers with manual operation (the robot moves to them when a destination is commanded) have already been commercialized and commercialized. Have been.

All of these teaching devices use the above device to move the manipulator to a destination (teaching point) arbitrarily measured in a work space of a robot (manipulator) and store the teaching point. Is taught.

A teaching playback technique has been proposed in which a human directly grasps a hand of a manipulator and guides a trajectory to be taught to teach. In addition, a method using CAD data has been proposed, but has not yet reached a practical level. Note that teaching using the above-described teaching box or the like is referred to as “indirect teaching”, and teaching performed directly with the manipulator is referred to as “direct teaching”.

[0005]

The conventional "teaching playback method" in which a human being holds a manipulator with his / her hand has the following problems.

(1) Precise positioning becomes difficult due to an increase in human labor (including time) due to an increase in the size of the manipulator (the manipulator cannot be brought to a point to be easily taught). (2) There is a great danger due to the collaborative work between the human and the manipulator.

Further, the teaching using a teaching box or the like has the following problems. (1) To move the manipulator, x, y, z
Must be considered, and the intuition of the movement is very poor. (2) The motion of the manipulator is three-dimensional and x,
Since it has three components of y and z, it is impossible to move the manipulator to an arbitrary teaching point by one button operation or the like. (3) Since the number of operation buttons is large, the operation often becomes confusing.

[0008] Although it has not been put to practical use, the one using the non-contact three-dimensional distance sensor device used in the present method has the following error problem. (1) Measurement error of 3D distance sensor itself (2) Calibration error existing between sensor and manipulator

[0009]

A non-contact point teaching device according to the present invention for solving the above-mentioned problems has a pointing rod capable of easily pointing a point in a three-dimensional space, and a tip of a manipulator.
It is fixed to the end and the tip of the indicator rod is
First and second photographing devices for photographing, and sensor
Control with control unit, manipulator control unit and teaching unit
It has a unit, at the time of teaching, the sensor system
The control unit is a two-dimensional image obtained by photographing with the first photographing device.
Image and two-dimensional image obtained by photographing with the second photographing device
By using the principle of triangulation based on
3D elements between the tip of the data and the tip of the pointer
The manipulator control unit obtains the distance for each element,
3D between the tip of the purator and the tip of the pointer
The distance for each element is always a predetermined three-dimensional
Pointed at the manipulator tip when it is close to the specified distance
Operate the manipulator to track the tip of the rod,
The teaching unit includes a tip of a manipulator and a tip of a pointing rod.
Of the teaching rod based on the distance of the manipulator and the position of the tip of the manipulator
Find the position of the tip and record this position as the teaching position.
And憶storage, during playback execution, the Manipi
The controller reads the teaching position from the teaching unit.
And the position of the tip of the manipulator is the read teaching position.
Operating the manipulator so as to be located at the position (1 ). Further, the non-contact point teaching device according to the present invention includes an indicator rod that can easily indicate a point in a three-dimensional space ,
It is fixedly attached to the tip of the manipulator and
Photographing device and manipulator for photographing the tip of pointing rod
The tip of the indicator rod is fixedly attached to the tip of
A distance sensor for measuring the distance to a non-contact sensor system
Control unit equipped with a control unit, a manipulator control unit, and a teaching unit.
And at the time of teaching, the sensor control
The unit is a two-dimensional image obtained by imaging with the imaging device and
The distance measured by the distance sensor is a three-dimensional distance measurement
Calculation, the tip of the manipulator and the tip of the pointer
Find the distance of each element in three dimensions from the edge,
The manipulator control unit controls the tip of the manipulator and
The distance of each 3D element from the tip of the rod is always
Predetermined close distance for each three-dimensional element
So that the tip of the manipulator tracks the tip of the pointer.
The teaching unit operates the manipulator
The distance between the tip of the
The position of the tip of the teaching rod is calculated based on the position of the tip of the
Is stored as a teaching position, and when playback is executed
In the above, the manipulator control unit is provided with the teaching unit.
From the teaching position, the position of the tip of the manipulator is
Move the manipulator so that it is located at the read teaching position.
It is characterized by operating. Non-contact according to the present invention
In the point teaching device, the manipulator control unit includes a playbar.
When executing the lock, the teaching position read from the teaching unit
The trajectory is derived by interpolating between the
Move the tip of the manipulator along the way
The method is characterized in that the manipulator is operated .

Hereinafter, the contents of the present invention will be described.

1. Here, in the present invention, a predetermined position in a three-dimensional space is shown using a pointing rod. For example,
If you use a pointer stick for presentations,
The coordinates of the point (x, y, z) in the dimensional space can be easily and once indicated. Therefore, the following problems (1) and (2), which are the conventional problems, are solved. (1) Reduction of human labor burden in direct teaching (2) Improvement of intuitiveness of manipulator operation instructions in indirect teaching

2. In the present invention, the three-dimensional distance sensor is mounted on the tip of the manipulator, and the manipulator is controlled so as to track the tip of the pointing rod while maintaining a predetermined distance, so that the measurement is always performed near the tip of the pointing rod. This method is as follows: (1) The measurement target is always measured close. (2) Since the positional relationship with the manipulator is restricted by hardware (a sensor is mounted at the tip of the manipulator), the following problems (1) and
(2) is solved. (1) Measurement error of 3D distance sensor itself (2) Calibration error existing between sensor and manipulator

[0013]

The teaching device of the present invention shown in FIG.
A non-contact point teaching method will now be described. Manipulator 11
Is the manipulator reference coordinates (x_m-Y_m-Z_m) 12
Manipulator hand coordinates (x_n-Y_n-Z_n)
13 position and posture r_m= (X _m, Y_m, Z_m, Α_m,
β_m, Γ_m).

The present invention relates to the above x_m, Y_m, Z_mTeach
Mainly to do_m, Β _m, Γ_mIs the traditional
Perform with a teaching box or the like. Posture α_m,
β_m, Γ _m[Deg] is the number of rotations around the x, y, and z axes, respectively.
In the turning angle, the order of the rotation is, for example, α on the x axis._m, Y-axis
To β_m, Z axis_mThen, as a rotation transformation matrix,

(Equation 1) Given by

The position and orientation relationship between the manipulator hand coordinates 13 and the sensor reference coordinates 14 is r ₀ = (x ₀ , y ₀ ,
z ₀ , α ₀ , β ₀ , γ ₀ ) are mechanically coupled in hardware and have the relationship already measured and according to the above rotation transformation matrix,

(Equation 2) Given by

The distance sensor 15 provided at the tip of the manipulator is used to detect the three-dimensional position (x _s ,
y _s , z _s ) is measured, but the manipulator 11 needs to be controlled by the control means 17 so that the distance between the two is constant (x _i , y _i , z _i ) in order to always measure the indicator rod 16 in the vicinity. Occurs. That is,

(Equation 3) As but becomes zero, the sensor control unit 18 of the command value r _m of the manipulator 11 as a control unit 17, the difference may be controlled by the teaching unit 19, and the manipulator control unit 20 (both ([Delta] x, [Delta] y, Delta] z) of Move the manipulator back).

This follows the following procedure.

(1) Correction of offset between manipulator hand coordinates and sensor coordinates

(Equation 4)

(2) Generation of command value based on manipulator reference coordinates

(Equation 5) Since Δr ′ is an xyz component, it is extended to six components including the posture (all components are zero because the posture is not taught). Δr = (Δx _r Δy _r Δz _r 0 0 0)

(Equation 6) Given by

The teaching data includes a manipulator command value r _m ^* obtained by the above procedure in response to the data input from the instructor, the relative amount r ₀ between the manipulator hand coordinates 13 and the distance sensor reference coordinates 14, and the distance sensor. Coordinate 14
By using the measurement distance r _s to fescue tip 16a from r command ^{_{= r m * + r 0 +}} r s ( _{although, r s = (x s,} y s, z s, is given by 0, 0, 0) .

The method of storing and executing the teaching data in the memory is as follows: (1) The above data r command is continuously stored in the memory, and the playback is executed as it is. (2) The r command of the main point in the operation trajectory is stored in the memory. During playback, execution is performed while orbit interpolation is performed. (3) The angle of each joint of the manipulator is obtained from the r command obtained in the above method (1) or (2) and stored in memory in the form of a θ command. An execution method such as playback execution can be considered based on this.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below. FIG. 1 is a basic configuration diagram, and there are several examples according to the method of a pointing rod and a distance sensor. That is, if the difference of embodiments occurs in obtaining the r _s of FIG. 1, after the approach is the same as according to the method described above.

(Embodiment 1) First, FIG. 2 shows a first embodiment.

Using two ITV cameras (first ITV camera 21 and second ITV camera 22),
The triangulation of the LED [Light Emitting Diode] (or halogen lamp) 23 at the end of No. 6 is performed. A small ITV camera that can be mounted on the manipulator is a CCD.
Cameras are common, but not limited thereto.

As shown in the figure, the first ITV camera 2
Using ( ₁ ), (x ₁ , y ₁ ) is measured as a perspective projection of the position of the LED 23 provided at the tip of the pointing rod 16. Similarly, (x ₂ , y ₂ ) is measured by the second ITV camera 22. Both ITV cameras 21 and 22 are LED at different places
Since the perspective projection at the position 23 has been obtained, it is taken in by the computer executing the sensor control unit via the image memory 22 and the sensor reference coordinates 14 based on the principle of triangulation 23 according to the center position of the LED 23 derived by the image processing. LED23 position indicator rod tip as viewed from _{r s = (x s, y} s, z s) is calculated.

(Embodiment 2) FIG. 3 shows two first and second two-dimensional PSD cameras (light source 2) known as light receiving elements.
A second embodiment of the present invention is shown, which is constituted by measuring rods 31 and 32 and an indicator rod 16 having an LED (or halogen lamp) 23 at the tip.

This system is also similar to the first embodiment in that the first and second
A / D converter 3 using two-dimensional PSD cameras 31 and 32
3 and according to the principle of triangulation 34, r _s = (x _s , y
_s , z _s ).

(Embodiment 3) FIG. 4 shows a three-dimensional distance sensor constituted by an ultrasonic sensor 41 and an ITV camera 42.
Indicator rod 16 with ED (or halogen lamp) 23
A third embodiment is described.

The ultrasonic sensor 41 measures the vertical distance (y _s ′) 44 of the pointing rod 16 from the reflector 43, and the ITV camera 42 uses the two-dimensional coordinates (x _s ′, z _s ′) 4 of the LED 23.
Measure 5.

The vertical distance (y _s ') 44 by the ultrasonic sensor 41 is transmitted via an A / D converter 46 and
The two-dimensional coordinates (x _s ′, z _s ′) 45 of the V camera 42 are sent to the three-dimensional distance measurement calculation 48 via the image memory 47, and then taken into the calculator of the sensor control unit 18, and the like.
The three-dimensional distance r _s = (x _s , y _s , z _s ) of the pointing rod tip 16a viewed from the sensor reference coordinates 14 is obtained.

[0031]

As described above, according to the present invention, when teaching a manipulator, labor is required without being conscious of the coordinate direction (x, y, z) of the manipulator means viewed from the manipulator reference coordinates. The teaching point of the manipulator (the point at which the manipulator moves during playback) can be taught without any need. In addition, the problem of errors when using a conventional non-contact distance sensor can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of the basic principle of the present invention.

FIG. 2 is a configuration diagram showing a first embodiment of the present invention.

FIG. 3 is a configuration diagram showing a second embodiment of the present invention.

FIG. 4 is a configuration diagram showing a third embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 11 manipulator 12 manipulator reference coordinates 13 manipulator hand coordinates 14 sensor reference coordinates 15 distance sensor 16 indicating rod 17 control means 18 sensor control unit 19 teaching unit 20 manipulator control unit 21 first ITV camera 22 second ITV camera 23 LED (halogen) Lamp) 31 first PSD camera 32 second PSD camera 41 ultrasonic sensor 42 ITV camera 43 reflector 44 vertical distance 45 two-dimensional coordinates

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Taku Sasaki 2-1-1, Shinhama, Arai-machi, Takasago-shi, Hyogo Mitsubishi Heavy Industries, Ltd. Inside Takasago Research Laboratory (56) References JP-A-2-36406 (JP, A) JP-A-5-23983 (JP, A) JP-A-63-278779 (JP, A) JP-A-62-191904 (JP, A) JP-A-63-191562 (JP, A) JP-A-60-217418 (JP, A) JP, A) JP-A-4-333105 (JP, A)

Claims (3)

(57) [Claims] An indicator rod capable of easily pointing to a point in a three-dimensional space, and fixedly attached to a tip of a manipulator,
A first photographing device for photographing the tip of the pointing stick and a second photographing device;
Equipped with an imaging device, a sensor control unit, a manipulator control unit, and a teaching unit
And at the time of teaching, the sensor control unit captures an image using the first image capturing device.
Two-dimensional image obtained by
Using the principle of triangulation based on the two-dimensional image
Between the tip of the manipulator and the tip of the pointer.
The distance for each three-dimensional element is calculated, and the manipulator
The control unit is located between the tip of the manipulator and the tip of the pointer.
The distance of each three-dimensional element in is always a predetermined third order
It becomes a predetermined distance close to each original element and
So that the tip of the pointer follows the tip of the pointer.
Operating the teaching unit, the teaching unit is in contact with the tip of the manipulator.
Distance from the tip of the pointer and the position of the tip of the manipulator
The position of the tip of the teaching rod is determined based on the
When the playback is executed, the manipulator control unit transmits the teaching position from the teaching unit.
Was read, and the position of the tip of the manipulator was read.
Operate the manipulator so that it is located at the teaching position
A non-contact point teaching device , characterized in that: 2. An indicator rod which can easily point to a point in a three-dimensional space, and which is fixedly attached to a tip of a manipulator and has a front end.
Photographing device and manipulator for photographing the tip of pointing stick
The tip of the indicator rod is fixedly attached to the tip of
It has a distance sensor that measures the distance to non-contact, a sensor control unit, a manipulator control unit, and a teaching unit.
And at the time of teaching, the sensor control unit obtains an image by the imaging device.
The distance measured by the two-dimensional image and the distance sensor is 3
By dimensional distance measurement operation, the previous Manipyure over data
Distance between each element in three dimensions between the end and the tip of the pointer
The manipulator control unit calculates the separation
3D elements between the tip of the pointer and the tip of the pointer
The distance of each element is always a predetermined three-dimensional element.
At the specified distance, the tip of the manipulator is
Operate the manipulator to track
Is the distance between the tip of the manipulator and the tip of the pointer.
And the position of the tip of the teaching rod based on the position of the tip of the manipulator.
This position is obtained and stored as a teaching position, and at the time of playback execution, the manipulator control unit transmits the teaching position from the teaching unit.
Was read, and the position of the tip of the manipulator was read.
Operate the manipulator so that it is located at the teaching position
A non-contact point teaching device, characterized in that: 3. The method according to claim 1, wherein the manipulator control unit includes a
When executing the lock, the teaching position read from the teaching unit
The trajectory is derived by interpolating between the
Move the tip of the manipulator along the way
2. The method according to claim 1, wherein the operation of the manipulator is performed.
A non-contact point teaching device according to claim 2.