JPH05257527A - Detection of position and direction of unmanned vehicle - Google Patents

Abstract

PURPOSE:To provide the unmanned vehicle position and direction detecting method which requires only simple operation and detects the position of an unmanned vehicle with a high precision. CONSTITUTION:This detecting method has ceiling illumination lamps L1 to LN as position detection indexes of a guideless unmanned vehicle 20. Emitted light of each of ceiling illumination lamps L1 to LN has a peculiar modulation frequency, and the ceiling illumination lamp from which the light is received by a photodetector 22 is specified on the side of the unmanned vehicle 20 by the output frequency of the photodetector directed to the ceiling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a guideless type unmanned vehicle position / direction detecting method used in an unmanned vehicle system having no guide wire such as a guide wire or a magnetic tape.

[0002]

2. Description of the Related Art As a method of detecting the current position and direction of an unmanned vehicle of this type, for example, a light reflecting plate is attached to the ceiling,
A laser spot is projected from the laser oscillator mounted on the unmanned vehicle to the light reflecting plate, the laser spot is photographed by a visual device such as an ITV camera provided on the ground, and the current position and direction of the unmanned vehicle are detected from the image data. There is a way to do it.

However, this method has a drawback that the system becomes expensive because it is necessary to attach a light reflecting plate to the entire surface of the ceiling and it is necessary to dispose a plurality of ITV cameras.

[0004]

In order to solve this drawback, a detection method using a ceiling illumination lamp has been proposed as described in, for example, Japanese Patent Laid-Open No. 60-89213. The detection method is a pattern matching method that compares a partial image of the ceiling taken by a visual device such as an ITV camera with an image of the entire ceiling that is stored in memory in advance. However, it may be inaccurate if the software processing is complicated and the ceiling lighting is regularly arranged or the number of ceiling lighting in the visual field of the visual device is small.

The present invention has been made to solve this problem, and a system can be constructed at low cost by using a ceiling illumination lamp, and the calculation for position detection can be performed simply and reliably. An object of the present invention is to provide a position / direction detection method for an unmanned vehicle, which is capable of detecting the position / direction of the unmanned vehicle with high accuracy.

[0006]

In order to achieve the above object, the present invention provides a position detecting method for an unmanned vehicle in which a ceiling illumination lamp is used as a position detection index for a guideless unmanned vehicle. Each light emits light with a characteristic that can be individually identified, and on the unmanned vehicle side, the ceiling illumination lamp that the light receiving element receives is determined from the above characteristics of the output of the light receiving element toward the ceiling. ..

Detection method.

In the second aspect, the light emission of each ceiling illumination lamp has a different modulation frequency.

According to a third aspect of the present invention, a part of the ceiling is photographed by a visual device mounted on an unmanned vehicle, and the tilt angle and pan angle of the unmanned vehicle with respect to the central coordinates are calculated from the central coordinates of the ceiling illumination image in the screen. , The attitude of the light receiving element provided on the unmanned vehicle is controlled based on the tilt angle and the pan angle to receive the light of the corresponding ceiling illumination lamp, and the ceiling illumination lamp is specified from the output frequency of the light receiving element, The position of the specified ceiling illuminating lamp is specified from the illuminating lamp data memory in which the coordinate corresponding to the illuminating lamp number is written, and the position of the unmanned vehicle is detected by calculation from this position and the tilt angle.

According to another aspect of the present invention, the reference angle of the unmanned vehicle is determined from the angle formed by the direction connecting the projected position of the specified ceiling illumination lamp onto the reference plane and the detected position of the unmanned vehicle with respect to the reference direction, and the pan angle. The direction to the direction is detected.

In the fifth aspect, the orientation of the unmanned vehicle is detected by the gyroscope.

[0012]

In the present invention, the tilt angle and pan angle of the ceiling illumination lamp with respect to the unmanned vehicle are detected from the image data of the ceiling illumination lamp image in the captured ceiling image, and the light receiving element is directed to the ceiling illumination lamp. The output is used as an index to identify the ceiling illuminating lamp and detect the position, and the position of the unmanned vehicle is calculated based on this position and the tilt angle.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 10 is a building of a factory, 11 is a horizontal ceiling of the building 10, and L _{1 to} L _N are fluorescent lamps arranged on the inner surface of the ceiling 11. Reference numeral 20 denotes a guideless type unmanned vehicle that travels in the building 10, and is equipped with an ITV camera 21 and a light receiving unit 22.

The fluorescent lamps L _{1 to} L _N are inverter fluorescent lamps, and each generate a modulated light modulated at different frequencies F _{1 to} F _N. FIG. 4 shows an example thereof. In the figure,
Reference numeral 12 is a power source, 13 is a rectifier, 14 is a smoothing capacitor, 15 is an oscillating circuit, and 16 is a fluorescent tube.

The ITV camera 21 is mounted at a certain elevation angle so that a part of the ceiling 11 can be accommodated in the field of view, and the light receiving unit 22 is provided with a light receiving element 23, right and left and up and down as shown in FIG. A dynamic drive mechanism 24 and a control device 25 are provided, and the tilt angle α and the pan angle β (shown in FIG. 3) of the light receiving element 23 with respect to the unmanned vehicle 20 are adjustable.

FIG. 4 shows an image taken by the ITV camera 21, and the image signal from the ITV camera 21 is binary data (bright [1] and dark [1] as shown in FIG.

After being converted into [0]), it is stored in the image memory 32. 5A shows a vertical section of the field of view of the ITV camera 21, and FIG. 3B shows a horizontal section of the field of view of the ITV camera 21. In FIG. 2, reference numeral 33 is a processor CPU, and 34 is an illumination lamp data memory. The illumination lamp data memory 34 stores a table of fluorescent lamp numbers L _{1 to} L _N , frequencies F _{1 to} F _N, and fluorescent lamp coordinates g _{1 to} g _N. 34A is a data memory for storing the calculation result of the arithmetic unit CPU 33.

(1) In the arithmetic unit CPU 33, the complete images L ₁ ^' and L ₂ of the fluorescent lamp images (bright areas) L ₁ ^{' to} L ₄ ^' of the image data for one frame stored in the image memory 32 are stored. image center G _1, coordinates G ₁ of G ₂ of ^{_{'(i 1, j 1)}} ,
The coordinates G ₂ (i ₂ , j ₂ ) are calculated. Image center G ₁ , G ₂
Since the positions of the pixels of the image centers G ₁ and G ₂ are displaced by shifting the image centers G ₁ and G ₂ , the positions of the pixels of the image centers G ₁ and G ₂ in all the pixels, that is, the horizontal pixel address and the vertical pixel address) are unmanned. Corresponds to the tilt angles α ₁ and α ₂ and the pan angles β ₁ and β ₂ as viewed from above. The tilt angles α ₁ and α ₂ and the pan angles β ₁ and β ₂ are stored in the data memory 34A.

(2) The tilt angle α ₁ and pan angle β ₁ and the tilt α ₂ and pan angle β ₂ are input to the control device 25 of the light receiving unit 22. First, the light receiving surface of the light receiving element 23 is a fluorescent lamp L. _By controlling the posture toward ₁ , the light from the fluorescent lamp L ₁ is received, the output of the light receiving element 23 is input to the frequency detection circuit 35, and the modulation frequency F ₁ is detected. Subsequently, the light receiving element 2 to the position in which the light receiving surface of the light receiving element 23 faces the fluorescent lamp L ₂
3 and controls the output of the light receiving element 23 to the frequency detection circuit 35.
To the modulation frequency F ₂ to be detected.

(3) The arithmetic circuit CPU 33 collates the thus obtained modulation frequencies F ₁ and F ₂ with the above table of the illuminating lamp data memory 34 to obtain real images corresponding to the images L ₁ ^′ and L ₂ ^′. Are fluorescent lamps L ₁ and L ₂ .

(4) The arithmetic circuit CPU 33 uses the fluorescent lamp L ₁
And reads out the coordinates g ₁ g ₂ of L ₂ from the lighting data memory 34, calculates a circle O ₁ shown in FIG. 6 from the tilt angle alpha ₁ Metropolitan read from coordinates g ₁ and the data memory 34A, similarly, lighting A circle O ₂ shown in FIG. 6 is calculated from the coordinate g ₂ read from the data memory 34 and the tilt angle α ₂ . The unmanned vehicle 20 is located on the intersection A or B on the circumference of the _two circles O ₁ and O ₂ , and the magnitude relationship between the pan angles β ₁ and β ₂ (the left-right relationship between G ₁ and G ₂ ). ) Is the position P of the unmanned vehicle 20
Specify.

[0022] (5) when detecting a δ direction of the unmanned vehicle 20 (position) is thus positioned g ₁ position P and the fluorescent lamp L ₁ of the unmanned vehicle 20 identified by (or the fluorescent lamp L ₂ The angle γ with respect to the reference direction X shown in FIG. 7 is calculated from the position g ₂ ) and the direction δ of the unmanned vehicle 20 is calculated from the sum of the angle γ and the pan angle β ₁ (or the pan angle β ₂ ).

As described above, in this embodiment, each fluorescent lamp L ₁
˜L _N have unique modulation frequencies F _{1 to} F _N , it is possible to easily identify the fluorescent lamps L ₁ and L ₂ that serve as position detection indexes, and use the coordinates of the identified fluorescent lamps. Since the position and direction of the unmanned vehicle 20 are detected by using the conventional pattern matching method, simple software is required, and the fluorescent lamps L ₁ and L ₂ can be reliably identified. Therefore, there is no fear of detection failure, and the position and direction can be detected reliably and with high accuracy.

Further, since the position of the ceiling illumination lamp is specified from the modulation frequency, there is an advantage that the arrangement method of the fluorescent lamps is not limited.

In the above embodiment, the direction of the unmanned vehicle 20 is calculated. However, as shown in FIG. 8, a gyroscope is mounted on the unmanned vehicle 20 and the direction of the unmanned vehicle 20 is determined by the gyroscope. You may make it detect.

As the light receiving element 23, for example, a photoelectric conversion element capable of responding to a frequency of several tens of KHZ, specifically, a photodiode is used. However, if the diode is provided with a megaphone hood and the directivity is improved, a specific Only the frequency component is emphasized, and it becomes easy to discriminate in the frequency detection circuit 35 in the subsequent stage.

Further, the frequency detection circuit 35 extracts the one having the highest peak value from the plurality of frequency components included in the output from the light receiving element 23. Specifically, there is an FFT analyzer using a Fourier transform method, but when the directivity of the light receiving element 23 is improved by the above method, it is possible to make do with a simple pulse counter.

If the ITV camera 21 can capture only one fluorescent lamp in its field of view, ITV
The image of at least another fluorescent lamp is captured by changing the angle of the camera 21. In this case, when changing the angle of the ITV camera 21, it is advantageous in terms of calculation time to prioritize the pan angle over the tilt angle.

When high precision positioning is required,
The image of the original angle and the image of the current angle are combined to handle the image of the virtually expanded field of view. If such accuracy is not required, when a plurality of fluorescent lamps are captured in one visual field, it is sufficient to process only the image in that visual field.

[0030]

As described above, according to the present invention, when the ceiling illumination light is used as the position (and direction) detection index of the guideless unmanned vehicle, the light emission of each ceiling illumination light has its own modulation frequency, By configuring the position of the ceiling illuminator from this modulation frequency, the system can be constructed inexpensively using the ceiling illuminator, and the calculation for position detection can be performed easily and reliably. The position and direction of the unmanned vehicle can be detected with high accuracy.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 2 is a control block diagram for explaining a detection process in the above embodiment.

FIG. 3 is a circuit diagram of the fluorescent lamp in the above embodiment.

FIG. 4 is a diagram showing an example of a captured image of the ITV camera in the above embodiment.

FIG. 5 is a diagram for explaining a tilt angle and a pan angle in the above embodiment.

FIG. 6 is a diagram for explaining position detection calculation of an unmanned vehicle in the above embodiment.

FIG. 7 is a diagram for explaining the direction detection calculation of the unmanned vehicle in the above embodiment.

FIG. 8 is a diagram for explaining another example of detecting the position and direction of the unmanned vehicle in the above embodiment.

[Explanation of symbols]

10 Building 11 Ceiling 20 Unmanned Vehicle 21 ITV Camera 22 Light-Receiving Unit 31 Binarization Circuit 32 Image Memory 33 Arithmetic Circuit 34 Lighting Data Memory 34A Data Memory 35 Frequency Detection Circuit L _{1 to} L _N Fluorescent Lamp as Ceiling Lighting

Claims (5)

[Claims] 1. A method for detecting the position of an unmanned vehicle using a ceiling illumination light as a position detection index for a guideless type unmanned vehicle, wherein each ceiling illumination light emits light having a characteristic that can be individually identified, and on the unmanned vehicle side. A position / direction detecting method for an unmanned vehicle, characterized in that a ceiling illuminating light received by the light receiving element is specified from the characteristics of the output of the light receiving element toward the ceiling. 2. The method for detecting the position / direction of an unmanned vehicle according to claim 1, wherein the respective lights emitted from the ceiling illumination lamps have different modulation frequencies. 3. The tilt angle and pan angle of the unmanned vehicle with respect to the center coordinates are calculated from the center coordinates of the ceiling illumination image in the screen by photographing a part of the ceiling with a visual device mounted on the unmanned vehicle,
Based on the tilt angle and the pan angle, the attitude of the light receiving element provided on the unmanned vehicle is controlled to receive the light of the corresponding ceiling illumination lamp, and the ceiling illumination lamp is specified from the output frequency of the light receiving element to perform illumination. The position of the specified ceiling illuminating lamp is specified from the illuminating lamp data memory in which the coordinates corresponding to the lamp number are written, and the position of the unmanned vehicle is detected by calculation from this position and the tilt angle. The method for detecting the position / direction of an unmanned vehicle as described in 2. 4. A direction with respect to the reference direction of the unmanned vehicle from an angle formed by a direction connecting a projection position of the specified position of the ceiling illumination lamp onto the reference plane and the detected position of the unmanned vehicle with respect to the reference direction and a pan angle to the reference direction of the unmanned vehicle. 4. The method for detecting the position / direction of an unmanned vehicle according to claim 3, wherein: 5. The position / direction detection method for an unmanned vehicle according to claim 3, wherein the orientation of the unmanned vehicle is detected by a gyroscope.