JPH10291180A - Position and attitude displacement detecting method for moving body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple measuring means to increase the position and attitude accuracies when a moving body with a rough position and attitude control mechanism is run. SOLUTION: Target patterns 3 to 6 are put on a running floor surface, multiple pattern detecting sensors S1 to S4 are arranged on the bottom surface of the moving body 1 at those positions corresponding to the boundaries of the target patterns, and it is detected whether or not the position of each of the pattern detector sensors S1 to S4 is within the boundaries 3 and 4 of the target patterns provided on the floor surface. Thus the displacement direction of the position and attitude of the moving body 1 relative to the positions of the target patterns 3 to 6 is judged so as to correct a running route before running.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the control of the position and orientation of a moving body such as a micromachine or an autonomous vehicle, and more particularly, to the correction of accumulated errors in a moving body having only coarse positioning accuracy to enhance the position and orientation accuracy. The present invention relates to a simple method for detecting a deviation in position and orientation.

[0002]

2. Description of the Related Art Conventionally, for control of the position and orientation (direction) of a moving body, there has been a system in which the moving body has a camera and travels by judging the position and posture by image processing technology. According to such a method, even if there is no fixed trajectory, the moving body can be moved along the determined route, and the moving body can be moved as desired because it is not bound by the trajectory. However, in order to autonomously travel while properly maintaining the position and orientation of the moving object as planned, complicated and expensive devices such as an imaging device and an image processing device are required, and miniaturization is difficult.
In particular, in the case of having only a limited transfer capability such as a micromachine, it is difficult to provide a camera and an image processing device, and a method of processing a camera image to obtain a correct position and orientation cannot be adopted.

There is also a method in which a mark is provided on a moving body and the mark on the moving body is tracked and measured by an external camera. Japanese Patent Application Laid-Open No. 61-277010 discloses a method in which a plurality of marks three-dimensionally distributed on a space or a moving body are provided, and the position and orientation of the camera are calculated by observing the marks with a camera provided on the other. A method for measuring the position and orientation of a moving object based on this is disclosed. By observing a plurality of three-dimensionally distributed marks, it is possible to reduce the error parameter of the camera and measure the position and orientation of the moving object with high accuracy. The method using such a camera has a drawback that the measurement range is limited due to the restriction of the viewing angle. Furthermore, it is not suitable to use the measuring device mounted on a complicated, heavy and small moving object for advanced processing.
It also becomes expensive. There is also a method of estimating the current position by obtaining a traveling route based on a built-in position sensor such as a gyro. In this method, it is unavoidable that errors included in the estimation of the traveling route accumulate as the traveling route becomes longer and the estimated value of the current position becomes increasingly inaccurate. Therefore, it has been difficult to perform highly accurate positioning.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a simple position and orientation detection method capable of accurately positioning a moving body, and to provide a simple and lightweight positioning sensor mechanism. The object is to provide a mobile body that is equipped. In particular, it is equipped with a small-sized low-power actuator or autonomous vehicle that wants to omit even the slightest load, such as a micromachine, so that errors in position and posture can be corrected with sufficient accuracy after approaching the target position by coarse position and posture control. An object of the present invention is to provide a positioning sensor mechanism used for knowing.

[0005]

In order to solve the above-mentioned problems, the present invention provides a method for detecting a shift in the position and posture of a moving object, comprising the steps of: applying a target pattern on a traveling floor surface; At the position corresponding to the boundary of the target pattern, and by detecting whether each pattern detection sensor position is within the boundary of the target pattern provided on the floor surface, the position and posture of the moving body with respect to the target pattern position It is characterized in that the direction of deviation is determined and the traveling trajectory is corrected. According to the method of the present invention, if the moving body is at a predetermined position with respect to a simple target pattern applied to the floor surface, the output of the pattern detection sensor becomes a predetermined combination. The position and orientation of the moving object can be estimated. Since the target pattern is fixedly installed on the floor in advance, the displacement between the target pattern and the moving object can be determined by inspecting the output of the pattern detection sensor for the target pattern at an appropriate position in the trajectory of the moving object. You can know.

For example, when the vehicle is guided by a built-in gyro, errors in the position and orientation may accumulate as the traveling distance increases, and eventually deviation from the track may become unacceptable. In the method of the present invention, while following a trajectory with coarse accuracy by built-in guidance means or remote control means, the position and posture of the moving body are sometimes shifted by a pattern detection sensor near an appropriate target pattern installed on the floor surface. Can be measured. The measurement result is the direction of deviation from the position of the target pattern, but it alone can correct the position and orientation at that position, and without correcting at that position, the direction of trajectory correction toward the next fixed point It will be the information to instruct. According to such a method, a simple mechanism is sufficient since the guidance means of the moving body may be rough accuracy, and the position and orientation detection mechanism for executing the above method is mainly composed of a small and light sensor such as a photovoltaic cell. Since the elements can be very simple, they can be incorporated into a moving body having a very small load such as a micromachine so that highly accurate traveling can be performed.

[0007] The target pattern used in the method of the present invention may be a pattern in which the coloring surfaces sandwiched by intersecting straight lines are arranged point-symmetrically.
The sensors can be attached to the vertices of the parallelogram so that the symmetric center point of the target pattern is compared with the center position of the parallelogram where the sensors are arranged. The coloring is performed to distinguish one side of the straight line from the other side, and any color can be used as long as the pattern detection sensor can detect on which side the straight line is located. Irrespective of the type, and a distinction based on a difference in brightness may be used. The target pattern may be a checkerboard pattern covering the floor surface, and in this case, it is preferable that the sensor of the moving body is mounted at the vertex position of the rectangle. The pattern installed over the floor may be decorated as it is. Conversely, a floor pattern provided as a decoration can be used as it is as a target pattern in the method of the present invention.

The target pattern may be a pattern scattered on the floor. If the moving object itself has simple guidance means, move to a position near the position of the appropriate target pattern, use the target pattern to detect the displacement of the position and orientation of the moving object, and correct the trajectory. Just do it. The dotted pattern need only be applied to necessary places, and the construction cost can be saved. Of course, the aesthetic appearance of the room may be enhanced by using a highly decorative pattern. Note that the target pattern scattered on the floor may be a parallelogram pattern. Further, a honeycomb pattern may be used as a target pattern applied to the floor surface. The honeycomb pattern has a different aesthetic appearance from the checkered pattern. In order to make the surface sandwiching the straight line a different color, the honeycomb pattern must be color-coded in at least three colors. In such a case, it is preferable to use a sensor capable of coloring and distinguishing colors. However, it is also possible to detect the position and orientation by using, for example, two hexagons having one side interposed therebetween. In this case, the color used for the hexagon and another color are used. It only needs to be able to distinguish.

The moving body of the present invention has a positioning mechanism and controls the position and orientation to travel autonomously.
The number of sensors is attached to the vertex position of a parallelogram on the bottom surface, and the displacement of the position and orientation is detected based on the target pattern on the floor surface. With this configuration, accurate running control can be performed only by mounting a relatively simple, lightweight, and compact position and orientation control device.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for detecting a deviation of a position and a posture of a moving body according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a diagram illustrating a method for detecting a displacement of the position and orientation of a moving body according to an embodiment of the present invention.
A checkered pattern is applied to the floor on which the moving object moves. The checkered pattern is formed by alternately arranging square portions 3 and 4 having a dark color and square portions 5 and 6 having a light color. For example, the checker pattern can be formed even by laying square tiles. The moving body according to the present embodiment includes a gyro built-in guidance means capable of performing autonomous traveling with low accuracy according to a program. Therefore, it is possible to move to the vicinity of the predetermined pattern position by the guiding means.

Although the moving body has various external shapes depending on the application, the shape does not matter in the present invention. Therefore, in FIG. 1, only the outline is shown in FIG. The moving body 1 has four pattern detection sensors S1, S2, S on the bottom surface facing the floor surface.
3. S4 is installed. The pattern detection sensor has a simple structure in which a light emitting element and a light receiving element are incorporated in a pair, and a target is irradiated with predetermined light and the presence or absence of a reflecting surface is detected based on the intensity of the reflected light. The irradiation light is preferably visible light in which the reflection coefficients of the checkered dark portions 3 and 4 and the light portions 5 and 6 change significantly. In addition, infrared rays or ultraviolet rays can be used in order to reduce the influence of ambient light.

In FIG. 1, the moving body 1 is located near a place where a checkered pattern formed on the floor intersects. At this time, the first pattern detection sensor S1 and the second pattern detection sensor S2
Indicates that a dark portion is detected immediately inside the boundary of the dark region 3. Further, the third and fourth pattern detection sensors S3 and S4 similarly detect a dark portion in the inside along the boundary line of the dark region 4 opposed to the dark region 3 with the apex therebetween. ing. When the position of the sensor is slightly shifted and exceeds the boundary line, the adjacent light-colored areas 5 and 6 are detected and the output changes.

Since the pattern detecting sensor is disposed inside the boundary of the dark area, if the moving direction of the moving body 1 and the linear direction of the floor pattern coincide with each other, the moving direction of the moving body 1 is It is arranged so as to be located at four vertexes of a rectangle having a long axis in the direction of -45 ° and a short axis in the direction of + 45 °. However, the direction of the rectangle changes according to the relationship between the moving direction of the moving body 1 and the pattern, the selection of the target pattern, the detection target of the sensor, and the like.

The output state when a dark color area is detected is represented by "1", and the output when a light color area is detected is "0".
When the output of the pattern detection sensors S1, S2, S3, and S4 numbered in the clockwise direction is arranged in order, the state of FIG. 1,1,1). At this time, in the moving body 1, the center position of the sensor group matches the intersection of the checkered pattern, and the direction of the moving body matches the direction of the straight checkered ridge line. At this time, the direction of the rectangle formed by connecting the sensors has a 45 ° inclination with respect to the checkered ridge line.

FIG. 2 is a diagram showing how the detection vectors (S1, S2, S3, S4) change according to the positional relationship between the pattern and the moving body in this embodiment. FIG.
(A) shows the same state (1,1,1,1) as FIG.
This state serves as a reference, and there is no deviation in position and posture.
2 (b), (c), (d), and (e) show the case where any one of the pattern detection sensors detects a light-colored area. This is a state in which a shift has occurred in one of the three directions.

For example, in FIG. 2B, only the third sensor S3 among the pattern detection sensors detects the light-colored area 6 with the pattern slightly shifted to the right in the figure, so that the detection vector is (1,
1, 0, 1). As described above, when the third sensor S3 is “0”, the moving body 1 may be returned to the left.
In FIG. 2C, the first sensor S1 becomes "0" in a state shifted to the left side in the figure, so that it is returned to the right. FIG. 4D shows that when the moving body 1 is displaced upward in the drawing, the fourth sensor S4 becomes “0” and returns downward. FIG.
(E) is the case where the second sensor is “0” when it is shifted downward.
And return to the top.

2 (f), 2 (g), 2 (h) and 2 (i) show that the moving body has a composite displacement in two directions, the traveling direction and the direction perpendicular to the traveling direction, as compared with the reference position. In this state, two of the pattern detection sensors detect the light-colored area. For example,
FIG. 2F shows a state in which the third sensor S3 and the fourth sensor S4 detect the light-colored areas 6 and 5, respectively, in a state shifted to the upper right in the figure, and the detection vector is (1, 1, 0, 0). Becomes
In this case, since the third sensor S3 is "0", the moving body 1 is returned to the left, and the fourth sensor S4 is set to "0".
So return it to the bottom.

FIG. 2 (g) shows a state in which the second sensor S2 and the third sensor S3 are "0" in a state shifted to the lower right in the figure, so that the detection vector becomes (1, 0, 0, 1). , Returning upward according to the output of the second sensor S2, and returning left according to the output of the third sensor S3. Figure (h) shows the moving object 1
Is shifted to the lower left in the figure, and the detection vector is (0, 0,
1, 1), so return to the upper right. Also,
FIG. 2 (i) shows the detection vector (0, 0,
1, 1, 0).

FIGS. 2 (j) and 2 (k) show the case where the moving body is displaced in the rotational direction with respect to the reference posture, and two opposing pattern detection sensors detect a light-colored area. For example, FIG.
(J) shows a state in which the second sensor S is shifted clockwise in FIG.
Since the second and fourth sensors S4 detect the light-colored areas 6 and 5, respectively, the detection vector is (1, 0, 1, 0). In this case, the second sensor S2 is “0” and the fourth sensor S2
Since 4 is "0", the moving body 1 is moved upward on the side with the second sensor S2 and downward on the side with the fourth sensor S4, and is rotated counterclockwise to return. In FIG. 2 (k), since the detection vector is (0, 1, 0, 1), it can be seen that the posture has a counterclockwise deviation, and if the posture is rotated clockwise to return the posture. Good.

FIG. 3 is a perspective view showing the outer shape of a micro machine to which the method for detecting the displacement of the position and orientation of a moving body according to this embodiment is applied. In the figure, a micro machine 10 includes a pair of drive wheels 12 and one control wheel 13 in a cylindrical main body 11, and includes a simple autonomous traveling control device incorporating a gyro therein (not shown). Travel on the floor along the determined route. FIG. 4 is a bottom view of the micro machine 10 of FIG. Four pattern detection sensors S1, S2, S3, S4 are attached to the bottom of the main body 11 toward the floor. The four sensors are arranged at positions that are sandwiched between the straight lines extending in the traveling direction that cross each other at the center of the main body 11 and a straight line that is perpendicular to the straight lines. The mounting position of the sensor is determined so that a straight line portion of the floor pattern boundary can be observed when the point where the boundary of the floor pattern intersects with the center of the micromachine 10. In this embodiment, the four sensors are arranged at the vertices of a rectangle, and the distance from the center is equal. By arranging them symmetrically in this way, the weights of the information of each sensor become equal, and necessary information can be obtained by simple processing.

FIG. 5 is a front view of the micro machine 10. The pattern detection sensor S emits predetermined light vertically downward, receives light reflected from the pattern on the floor surface 15, and determines the pattern on the floor surface at that position from the intensity thereof. The irradiation light of the sensor S is determined according to the color of the target pattern, and a filter is provided on the front surface of the light receiving element to remove the light other than the irradiation light, thereby improving the accuracy of measurement. Ultraviolet rays or infrared rays may be used as the irradiation light. FIG. 6 is a perspective view showing a state where the micro machine 10 travels on a floor surface. The floor has a checkered pattern all over. The color of the pattern may be achromatic or chromatic. In the case of using ultraviolet rays or infrared rays, surface treatments having different reflectivities of these rays may be performed, and it is possible to make the pattern invisible to human eyes.

The micro machine 10 runs autonomously with the corner of the square determined by the built-in guidance device as an intermediate target. When it is considered that the guidance device has caused the micro machine 10 to reach the determined corner of the square, the displacement detecting mechanism of the present embodiment operates to detect the direction of the displacement of the position and the posture.
According to the detection information, it is preferable to correct the position and orientation of the micro machine 10 on the spot and reset the guidance error of the guidance device. However, a traveling mechanism having a high degree of freedom to enable this is light and small. It cannot be equipped on the micromachine 10 that is to the effect. Therefore, in the micro machine 10 to which the present embodiment is applied, the accuracy of the position and orientation at the next point is improved by taking in guidance information for guiding to the next target point as data to be corrected.

FIG. 7 is a drawing showing an example of another pattern applied to the floor surface. This example is a honeycomb pattern in which regular hexagons are connected without gaps, and is painted in three colors. The pattern detection sensors S1, S2, S3 and S4 are the darkest colored 21 and 2
It is arranged so as to correspond to the position just inside the boundary line of No. 2 and is adjusted to detect the planes 21 and 22. Here, the four pattern detection sensors are disposed at the vertices of a rectangle parallel to the direction of the moving body 1. Even in such a configuration, the displacement of the position and the posture is detected by the same logic as described above with reference to FIGS. In this configuration, the inclination of the pattern boundary line is different between the straight traveling direction and the direction perpendicular thereto, and the detection sensitivity is increased in the straight traveling direction. It is to be noted that only the surfaces corresponding to the surfaces 21 and 22 may be colored in a dark color and the same light color may be used without distinguishing the other surfaces. This is because the above detection is performed only on the surfaces 21 and 22. Also, the pattern detection sensor is colored 2
This is the same even if the adjustment is made so as to detect the third surface or the light-colored surface 24.

FIG. 8 is a diagram showing an example of another target pattern applied to the floor. In this example, the pattern is not spread, but is scattered only at a necessary position. Since the moving body has a separate guiding means of coarse accuracy, the target pattern 25
Can be moved to the vicinity of a certain position, and thereafter, by performing the pattern detection described above, it is possible to detect the displacement of the position and the posture of the moving body. In addition, since only a part of the boundary of the pattern side surface is required for the detection of the position and orientation, the shape of the pattern has a high degree of freedom. In FIG. 8, a circular pattern is added to the center to give a design. When the patterns are scattered in this manner, there is an effect that the construction cost and the maintenance cost are reduced as compared with the case where the patterns are spread over a wide area, and there is an effect that the design of the floor surface is free and the appearance is improved. FIG. 9 shows a target pattern constituted by a simple square. In this example, the pattern detection sensor S on the bottom surface of the moving body 1 is adjusted so as to detect the outside of the pattern 36. However, even in this case, the same operation and effect are exerted only by reversing the element values of the detection vector.

[0025]

As described above in detail, by using the method for detecting the displacement and the position of a moving body and the moving body according to the present invention, the load on a built-in guiding device or a remote guiding device can be significantly reduced. In addition, positioning with sufficient accuracy can be performed only by mounting a simple and lightweight displacement detecting mechanism. Therefore, the present invention has a great effect when applied to a moving body such as a micro machine having a small load capacity.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method for detecting a shift in the position and orientation of a moving object according to the present invention;
It is drawing explaining an Example.

FIG. 2 is a diagram showing a positional relationship between a pattern and a moving object and a change in a detection vector in the present embodiment.

FIG. 3 is a perspective view illustrating an outer shape of a micro machine to which a method for detecting a displacement of a moving body position and orientation according to the present embodiment is applied.

FIG. 4 is a bottom view of the micro machine of FIG. 3;

FIG. 5 is a front view of the micro machine of FIG. 3;

FIG. 6 is a perspective view showing a state in which the micro machine of FIG. 3 travels on a floor surface.

FIG. 7 is a drawing showing another example of a target pattern used in the present embodiment.

FIG. 8 is a drawing showing an example of a dotted target pattern used in the present embodiment.

FIG. 9 is a view showing another example of a target pattern used in the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Moving body 3, 4 Dark square part 5, 6 Light square part 10 Micro machine 11 Main body 12 Drive wheel 13 Steering wheel 15 Floor 21, 22 Dark part 23 Intermediate color part 24 Light part 25, 26 Target pattern S, S1, S2, S3, S4 Pattern detection sensor

Continued on the front page (51) Int.Cl. ⁶ Identification code FI G01C 15/00 G01C 15/00 A 21/00 21/00 A G05D 1/02 G05D 1/02 K A

Claims (7)

[Claims] 1. A target pattern is provided on a floor on which a moving object travels, and a plurality of pattern detection sensors are arranged on a bottom surface of the moving object at positions corresponding to boundaries of the target pattern. Detecting whether or not the position is within the boundary of the target pattern provided in the moving object, thereby determining the direction of deviation of the position and posture of the moving body with respect to the target pattern position, and correcting the traveling trajectory. A method for detecting the displacement of the body position and posture. 2. A pattern sandwiched between straight lines intersecting the target pattern is a pattern arranged symmetrically with respect to a point, and four sensors are attached to the bottom surface of the moving body at vertex positions of a parallelogram, 2. A method according to claim 1, wherein the center position of the symmetric center point of the target pattern is compared with the center position of the parallelogram in which four sensors are arranged. 3. The displacement of the position and posture of the moving body according to claim 2, wherein the target pattern is a checkered pattern, and four sensors are mounted on the bottom of the moving body at the apexes of a rectangle. Detection method. 4. A pattern comprising a point symmetrical figure sandwiched between straight lines intersecting the target pattern and scattered on a floor surface, wherein four sensors are mounted on the bottom surface of a moving body at rectangular vertex positions. 3. The method according to claim 2, further comprising the steps of: 5. The method according to claim 2, wherein the target pattern is a pattern scattered on a parallelogram floor, and four sensors are mounted on the bottom of the moving body at the apexes of the rectangle. For detecting the displacement of the position and posture of the moving object. 6. The moving body according to claim 2, wherein the target pattern is a color-coded honeycomb pattern, and four sensors are mounted on the bottom of the moving body at the apexes of a rectangle. Posture deviation detection method. 7. A moving body having a positioning mechanism and controlling the position and orientation to travel autonomously, wherein four sensors are attached to the apexes of a parallelogram on the bottom surface and the position is determined based on a target pattern on the floor surface. A moving object characterized by detecting a shift in posture.