JPH01193904A - Position correction device - Google Patents

Abstract

PURPOSE:To prevent a manipulator from becoming the obstruction of a transit, to eliminate the needs for constructing a floor, to calculate respective aberration quantities in a short time and to correct the action of the manipulator mounted on an unmanned vehicle by providing a position detector in the unmanned vehicle and providing an insulation body in a station. CONSTITUTION:When the unmanned vehicle 20 on which the manipulator is mounted stops at the station 21, the insulating boards 31 and 32 are arranged between respective surface light-emitting bodies 24-26 and the light-receivers 27-29 of the position detector 22. An aberration quantity calculation means obtains stoop position aberration in the Y-axis and X-axis of the unmanned vehicle 20 from light-receiving quantity signals from respective photodetectors arranged in a first direction, and obtains a rotary stop aberration from the light-receiving quantity signals from respective photodetectors arranged in a second direction, whereby the action correction means corrects the action position of the manipulator. The manipulator is prevented from becoming the obstruction of transit and the construction of the floor is eliminated. Furthermore, respective aberration quantity is calculated in a short time so as to correct the action position of the manipulator.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Industrial Application Field) The present invention provides an automatic guided vehicle equipped with a manipulator that stops at each station to perform work such as loading and unloading workpieces. The present invention relates to a position correction device that corrects the operating position of a manipulator based on positional deviation.

(Prior art) There are various ways to run an automated guided vehicle, but among these, a method that does not use a guidance line is equipped with an ITV (industrial television) camera or a CCD (solid-state imaging device) camera, and the image capturing system of these cameras is used. One method uses ultrasonic sensors to recognize the surroundings, and the other uses a built-in gyro that uses lasers and gas to run by recognizing the surroundings based on the image data obtained by the gyro. There are methods such as running according to a set pattern. When the automatic guided vehicle traveling in this manner and equipped with a manipulator reaches a station, it stops traveling and loads and unloads the workpieces by operating the mounted manipulator. However, when an automatic guided vehicle stops at a station, it may stop at a position shifted from a predetermined stopping position. In other words, if the traveling direction in which the automatic guided vehicle should stop is the Y-axis direction, and the direction perpendicular to this Y-axis direction is the X-axis direction, the automatic guided vehicle will deviate from these Y-axis and It may stop and may stop at an angle to the Y-axis direction.

By the way, the work data of the manipulator mounted on the automatic guided vehicle is taught for when the automatic guided vehicle accurately stops at the reference stop position. For this reason, if the automatic guided vehicle stops with a deviation from the reference stop position, the work by the manipulator cannot be performed with high accuracy. Therefore, in such a case, the stop position of the automatic guided vehicle is corrected by detecting the amount of deviation of the stop position, and the position of the work data of the manipulator is corrected based on the amount of deviation.

Among such corrections, FIG. 7 is a diagram showing a method of correcting the stop position of the automatic guided vehicle, and shows how to correct the stop position of the automatic guided vehicle 1 for each cone 2.3 placed on the floor when the automatic guided vehicle 1 stops. The respective fitting bodies 4 and 5 provided on the automatic guided vehicle 1 are fitted together to forcibly correct the position. FIG. 8 shows a method of correcting work data of a manipulator, in which a CCD camera 8 is provided at the tip of a manipulator 7 mounted on a transport vehicle 6, and a mark 10 for detecting deviation is placed on a gas station 9. It is attached. Then, when the automatic guided vehicle 6 stops traveling, the CCD camera 8 images the deviation detection mark 10 to determine the amount of deviation from the reference position, and the work data of the manipulator tuff is corrected in accordance with this amount of deviation.

However, in the method shown in FIG. 8, each of the cones 2 and 3 is placed on the floor, which obstructs the passage of workers, and further requires construction work to arrange these cones 2 and 3. or,
In the method shown in Figure 9, image processing must be performed to detect the amount of deviation in the Y-axis and become longer. Furthermore, the reliability of each calculated deviation amount is low.

(Problems to be Solved by the Invention) As described above, it obstructs traffic, requires construction on the floor, and takes time to calculate each amount of deviation.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a position correction device that does not obstruct traffic, eliminates the need for construction work on the floor, and can calculate each amount of deviation in a short time and correct the operating position of the manipulator. .

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a method for correcting the operating position of a manipulator based on a stop position shift when an automatic guided vehicle equipped with a manipulator whose operation has been taught in advance stops at a station. In the correction device, each photodetector provided in an automatic guided vehicle or station and having a surface emitter and a light receiver facing each other is arranged in a first direction, and a second direction different from the first direction is arranged.
a position detector arranged in a direction, and a position passing between a surface light emitter and a light receiver in a station or an automatic guided vehicle, and arranged in a first direction when the automatic guided vehicle stops at the station. A shielding body that blocks light by dividing each photodetector into each component in the X-axis and Y-axis directions, and also blocks light for each photodetector arranged in the second direction in response to a rotational position shift of the automatic guided vehicle; The deviation of the stop position of the automatic guided vehicle in the X-axis and Y-axis directions is determined from the received light amount signals from each photodetector arranged in one direction, and from the received light amount signal from each photodetector arranged in the second direction. The above objective is achieved by providing a total deviation calculation means for calculating the deviation of the rotation stop position of the automatic guided vehicle, and an operation correction means for correcting the operating position of the manipulator from each deviation amount calculated by the total deviation calculation means. It is a position correction device.

(Function) By providing such a means, when the automatic guided vehicle stops at a station, a shielding plate is disposed between each surface light emitter of the position detector and the light receiver.

Therefore, the deviation amount calculation means calculates the stop position deviation of the automatic guided vehicle in the Y-axis and X-axis directions from the received light amount signal from each of the photodetectors arranged in the first direction, and The rotation stop position deviation of the automatic guided vehicle is determined from the received light amount signal from each photodetector arranged in the direction, and the operation correction means corrects the operation position of the manipulator based on each calculated deviation amount.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is an overall configuration diagram of the position correction device, FIG. 1A is an external configuration diagram, FIG. 1B is a configuration diagram of a position detector, and FIG.
The figure is a functional block diagram. In the figure, 20 is an automatic guided vehicle, and 21 is a station. Note that the automatic guided vehicle 20 is equipped with a manipulator, but the first A
It is omitted in the figure and FIG. 1B. This automated guided vehicle 20
is running in the direction of arrow (a) according to a predetermined running pattern.

Now, on the bottom surface of this automatic guided vehicle 20, a position detector 22 as shown in FIG. 1B is provided.

This position detector 22 has a recess 23 formed in the center,
Each of the surface light emitters 24, 25 and 26 and each of the light receivers 27, 28 and 29 made of a photodiode or the like are arranged to face each other with the recess 23 interposed therebetween. Note that the surface light emitters 24 to 26 and the light receivers 27 to 29 constitute first, second, and third photodetectors, respectively. and,
Although not shown, a partition plate is provided between each of the surface light emitters 24 to 26 and each of the light receivers 27 to 29 to prevent interference of light. Specifically, each of the surface light emitters 24 to 26 is composed of a combination of a fluorescent lamp and a diffuser plate, a plasma display panel, etc., and is formed into a rectangular shape and has the same light emitting area. . The arrangement is such that the first and second photodetectors are arranged at a predetermined interval in the first direction in which the automatic guided vehicle 20 is to stop, that is, the Y-axis direction, and the third photodetector is the second photodetector. They are arranged at predetermined intervals in a second direction at a predetermined angle θ in the Y-axis direction when viewed from the vessel.

On the other hand, at the station 21, a shield 30 is installed on the position detector 2.
It is provided at a height position to be inserted into the recess 23 of No. 2.

This shielding body 30 is provided in a direction perpendicular to the Y-axis direction, and is formed of a first shielding plate 31 that blocks light from the Y-axis direction and a second shielding plate 32 that blocks light from the X-axis direction.

Next, the functional blocks will be explained. The automatic guided vehicle 20 is provided with a travel control device 40, and this travel control device 40 is equipped with the functions of a travel control section 41 and a deviation amount calculation section 42. The travel control unit 41 performs steering control according to a travel pattern to control travel and stop of the automatic guided vehicle 20, and particularly when stopped, each surface light emitting body 24,
It has a function of transmitting a light emission signal at each of 25° and 26°. These light emitting signals are transmitted to each surface light emitter 24 through a D/A (digital/analog) converter 43.
It is scheduled to be sent to the 26th. The deviation amount calculation unit 42 receives each received light amount signal output from each light receiver 27 to 29 and calculates the amount of stop position deviation from the set stop position in the Y-axis and X-axis directions and the amount of rotational position deviation in the Y-axis direction. It is composed of a position conversion table 44 and a calculation section 45. As shown in FIG. 2, the position conversion table 44 stores data on the shift position of the received light amount signal with respect to the current value. Note that A of the position conversion table 44
In the region B, each of the light receivers 27 to 29 is completely shielded by the first and second shields 31 and 32 and does not receive any light, and in region B, each of the light receivers 27 to 2 And it is in a state where the light is not blocked by the second shielding bodies 31 and 32.

In this case, each surface light emitter 24 to 26 and each light receiver 27 to 2
9 uses the same one, so each light receiver 27 to 2
The position conversion table 44 is shared by each of the nine received light amount signals. The calculation unit 45 receives each received light amount signal from the first and second photodetectors, converts the position using the position conversion table 44, and determines the stop position of the automatic guided vehicle 20 in the Y-axis and X-axis directions from these positions. In addition to calculating the amount of deviation, the second
In response to the received light amount signals from the third photodetector and the third photodetector, the position is converted using the position conversion table 44, and from these positions Y
The rotation stop position deviation amount of the automatic guided vehicle 20 in the axial direction is calculated, and the stop position deviation amount including the rotation stop position deviation amounts in the Y-axis and X-axis directions is converted into an X-Y coordinate by the rotation stop position deviation amount. It has the function of converting the data and creating it in the manipulator control device 46 as a correction value for the work data.

By the way, the stop setting position is set when half of the light emitting area of each of the surface light emitters 24 to 26 is blocked by the first and second shielding bodies 31 and 32, as shown in FIG. The amount of light received is approximately 0.35[A] as shown in Figure 2.
] corresponds to

The manipulator control device 46 has a function of correcting the position of the work data in response to each correction value and controlling the operation of the manipulator 47 in accordance with the corrected work data. Note that the received light amount signals outputted from each of the light receivers 27 to 29 are each digitized by an A/D converter 48 and sent to a calculation section 45.

Next, the operation of the apparatus configured as described above will be explained.

When the automatic guided vehicle 20 reaches the station 21 and stops, the travel control unit 41 stops the steering control and sends a light emission signal to each of the surface light emitters 24 to 26 to cause each surface light emitter 24 to stop.
~26 to emit light.

By the way, when the automatic guided vehicle 20 is stopped, the automatic guided vehicle 20 stops at the stop setting position, and the stop position deviation of the automatic guided vehicle 20 with respect to the station 21 is on the Y axis.

If each of the X-axis and the rotational direction is zero, half of the light emitting area of each of the surface light emitters 24 to 26 is blocked by the first and second shields 31 and 32, as shown in FIG. . However, the automatic guided vehicle 20 does not always stop at the set stop position as described above, and may be located at a position shifted in the Y-axis, X-axis, and rotational direction, for example, when each light receiver
It may stop at the 126' position. Therefore, various positions are possible for the stop position of the automatic guided vehicle 20, but to simplify the explanation, first, a case where a shift of 1 Tha occurs in the Y-axis direction as shown in FIG. 4 will be described.

If the amount of deviation a occurs in the Y-axis direction in this way, the light-shielding area of the surface light emitter 25 will be reduced by the light emitting area corresponding to the amount of deviation a. Therefore, the light receiver 28 outputs the amount of light received from the light emitting portion of the surface light emitter 25 that is not blocked by the first shield 31 as a light reception signal in the Y-axis direction, and the light receiver 27
The amount of light received at the light emitting portion that is not blocked by the second shield 32 is output as a received light amount signal in the X-axis direction. These received light amount signals are each digitized by an A/D converter 48 and sent to a calculation section 45. This calculation unit 45 calculates the position in the Y-axis direction from the current value of the received light amount signal from the light receiver 28 using the position conversion table 44 shown in FIG. - Find the position in the X-axis direction from the value using the position conversion table 44. Here, the current values of the received light amount signals for the set stop positions in the Y-axis and X-axis directions are both about 0.35 [A], and the position is calculated as 4.5 [mml]. Therefore, the calculation unit 45 calculates this stop setting position 4.5 [
The amount of deviation yl, xi in the Y-axis direction and the X-axis direction is determined from the deviation between the converted position and the converted position.

Next, a case will be described in which the automatic guided vehicle 20 is rotationally displaced with respect to the Y-axis direction and stops. In this case, if there is no rotational deviation, each surface light emitter 25, 26 will be in the first position as shown in FIG.
Half of the light emitting area is blocked by the shielding body 31.

However, when a rotational shift occurs, the light-shielding area of the light-emitting area changes. FIG. 6 shows a case where the surface light emitter 25 is rotated at its center position for ease of explanation. Here, as shown in FIG. 5, the intervals between the surface light emitters 25 and 26 in the Y-axis and
Assume that the position viewed from the surface light emitter 25 is arranged at a predetermined angle θ with respect to the Y-axis direction passing through the surface light emitter 25,
Furthermore, let P be the center position of the surface light emitter 26, and let q be the in parallel to the X-axis direction passing through the center position P of the surface light emitter 26. Then, when a rotational deviation occurs and the state shown in FIG. 6 occurs, the line q rotates by the same angle as the angle of the rotational deviation. Therefore, if the angle formed by the second direction and line r parallel to line q and passing through position P is θ-, and the angle formed by the edge of line q and the first shield 31 is Δθ, then , θ−θ′+Δθ...(1) holds true. Also, if the distance between line q and line r is y-, then θ-w-tan-' (y-y-)/x
...(2).

Here, if the automatic guided vehicle 20 causes a rotational deviation in the counterclockwise direction as shown in FIG. If this occurs, y' becomes a positive value with respect to y.

Now, in this state, the surface light emitting body 26 is connected to the first shielding body 31.
When the light is blocked by , the unblocked light emitting area of the surface light emitter 26 corresponds to y'. However, the surface light emitter 26
When the light emitted from the light receiver 29 receives the light and outputs the received light amount signal, the calculation unit 45 receives this received light amount signal and converts it into a position using the position conversion table 44 shown in FIG. Then, y' is calculated by calculating the deviation between this position and the set stop position. After this, the calculation unit 45 calculates this y-
is substituted into the above equation (2) to find θ-, and then the (1)
) Calculate and find Δθ from the equation. Note that this Δθ is Δθ= tan' y −/x
...You may calculate and obtain it from (3).

By the way, the above-determined stop position deviations yl and xi in the Y-axis and X-axis directions are values that include the rotational deviation of the automatic guided vehicle 20. Therefore, the calculation unit 45 converts the values of these stop position deviations yl and xi into a stop position deviation amount on the X-Y coordinates using the rotational position deviation Δθ.

The following formula is this conversion formula, X=xl・cos Δθ−yl ・sin Δθ
−= (4) Y=xisin Δθ−yl−
CO8Δθ ・(5) The calculation unit 45 calculates these (
Equations (4) and (5) are calculated to calculate the amounts of deviation in the X-axis and Y-axis directions, and these deviations are sent to the manipulator control device 45 as position correction values for the manipulator 47.

The manipulator control device 46 receives the position correction value, performs position correction on the work data, and controls the operation of the manipulator 47 in accordance with the corrected work data. In this way, workpieces are loaded and unloaded between the automatic guided vehicle 20 and the station 21.

In this way, in the above embodiment, when the automatic guided vehicle 20 stops at the station 21, each of the surface light emitters 24 to 26
A shielding plate 30 is arranged between the photodetectors 27 to 29 and the stop position deviation of the automatic guided vehicle 20 in the Y-axis and X-axis directions from the received light amount signal from each photodetector arranged in the first direction. In addition, the rotation stop position deviation Δ of the automatic guided vehicle 20 is determined from the received light amount signal from each photodetector arranged in the second direction.
θ is calculated, and the correction value for the operating position of the manipulator 47 is calculated from each of the calculated deviation amounts, so that X can be accurately adjusted with a simple configuration, especially when the automatic guided vehicle 20 of a traveling type that does not use a guide line is stopped. Stop position deviations and rotational position deviations in the axial and Y-axis directions can be determined, and the position of the operation of the manipulator 47 can be corrected from these deviation amounts. Therefore, after stopping the automatic guided vehicle 20, the workpieces can be loaded and unloaded with high precision without having to correct the position. Also, there is no need to construct the floor etc.

Note that the present invention is not limited to the above-mentioned embodiment, and may be modified without departing from the spirit thereof. For example, the position detector 22 may be provided at the station 21 and the shield 30 may be provided at the automatic guided vehicle 20. Further, as shown in FIG.
1 may be L-shaped, and the amount of deviation in the X-axis and Y-axis directions may be determined from the amount of light received at each portion not shielded by the shielding body 40, and the amount of deviation in the rotation angle may also be determined.

[Effects of the Invention] As detailed above, according to the present invention, it does not obstruct traffic, eliminates the need for construction work on the floor, and furthermore corrects the operating position of the manipulator by calculating each shift amount in a short time. It is possible to provide a position correction device that can

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of the position correction device, FIG. 1A is an external configuration diagram, FIG. 1B is a configuration diagram of a position detector, and FIG.
The figure is a functional block diagram, Figure 2 is a schematic diagram of a position conversion table, Figure 3 is a diagram showing an example of the stop position of an automatic guided vehicle, and Figure 4 is a diagram showing an automatic guided vehicle stopped shifted in the Y-axis direction. , 5th
6 and 6 are schematic diagrams for explaining the detection of rotation stop deviation, FIG. 7 is a diagram showing a modification, and FIGS. 8 and 9 are diagrams for explaining a conventional technique. 20...Automated guided vehicle, 21...Station, 22
...Position detector, 23...Recess, 24-26...
Surface light emitter, 27-29... Light receiver, 30... Shielding body, 40... Travel control device, 41... Travel control unit, 4
2... Displacement amount calculation unit, 44... Position conversion table,
45... Calculation unit, 46... Manipulator control device, 4
7... Manipulator. ji4 B Fig. 6 17g1 Fig. 9

Claims (1)

[Claims] In a position correction device that corrects the operation position of the manipulator based on a stop position shift when an automatic guided vehicle equipped with a manipulator whose operation has been taught in advance stops at a station, the surface light emitting body provided in the automatic guided vehicle or the station. and a position detector comprising photodetectors each having a photodetector facing each other arranged in a first direction and arranged in a second direction different from the first direction, and the surface of the station or the automatic guided vehicle. Each of the photodetectors, which is provided at a position passing between the light emitter and the light receiver and is arranged in a first direction when the automatic guided vehicle is stopped at the station, is divided into each component in the X-axis and Y-axis directions. a shielding body that separately blocks light and blocks light from each of the photodetectors arranged in a second direction in response to a rotational position shift of the automatic guided vehicle;
The stop position deviation of the automatic guided vehicle in the X-axis and Y-axis directions is determined from the received light amount signal from each of the photodetectors arranged in the first direction, and the deviation of the stop position of the automatic guided vehicle from each of the photodetectors arranged in the second direction is determined. The apparatus further comprises: a deviation amount calculation means for calculating the deviation of the rotation stop position of the automatic guided vehicle from the received light amount signal; and an operation correction means for correcting the operating position of the manipulator from each deviation amount calculated by the deviation amount calculation means. A position correction device characterized by: