JPH05240940A - Optical measuring system - Google Patents

Abstract

PURPOSE:To obtain an optical measuring system which can always accurately measure the three-dimensional positional relation between an object to be measured to which a light source station is installed and a measurement reference position to which a reflecting station is installed. CONSTITUTION:A plurality of recurrent reflectors CC are arranged at arbitrary intervals beside the running course 2 of a traveling object 1. The reflectors CC have an optical property which reflects incident light in the direction opposite to the incident direction. A laser measuring instrument 3 mounted on the object 1 makes scanning by turning two surface beams 41 and 42 having different inclination along reference planes belonging to the object 1. The instrument 3 detects the rotational scanning angle when the beam 41 or 42 hits one of the reflectors CC by detecting the reflected light from the reflector CC. The current position and inclined angle of the object 1 in a three-dimensional space are calculated based on the detected rotational scanning angle, inclined angles of the surface beam, and coordinate positions of the recurrent reflectors.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical measurement system, and more particularly, to a three-dimensional positional relationship between a light source station and a plurality of reflection stations arranged at positions distant from the light source station. System for measuring

[0002]

2. Description of the Related Art Various systems have heretofore been proposed for measuring the position and azimuth of a moving body that moves on land, on the water, or in the air by utilizing the reflection of light.

For example, in Japanese Examined Patent Publication No. 2-48069, at least three light reflecting means for reflecting light in the direction of incident light are installed at a position apart from a moving body, and a light beam is horizontally rotated and scanned from the moving body. , "A position and orientation detection device of a moving body" (hereinafter referred to as a first conventional technique) for measuring the position and orientation of the moving body by detecting the reflected light from the light reflecting means on the side of the moving body is disclosed. There is.

Further, Japanese Patent Publication No. 1-13553 discloses that
In the "moving body position / orientation detecting device" as disclosed in Japanese Patent Publication No. 48069/1990, a light receiving point and a light beam emitting point of the reflected light at each light reflecting means are obtained for each scanning of the light beam. A "position detecting method of a moving body" (hereinafter referred to as a second conventional technique) is disclosed in which the deviation is measured and the vertical emission angle of the light beam in the next rotation scanning is corrected based on the deviation. There is.

[0005]

The first prior art described above has a problem that the position and orientation of the moving body cannot be measured because the light beam does not hit the light reflecting means when the moving body tilts or moves up and down. was there. Further, the first conventional technique has a problem that it is possible to measure the two-dimensional coordinate position of the moving body, but it is impossible to measure the three-dimensional position and orientation of the moving body.

On the other hand, in the above-mentioned second prior art, even if the moving body tilts or moves up and down, the light beam can be surely applied to the light reflecting means, but a measurement error caused by the tilting or up-and-down movement of the moving body. There was a problem that could not be corrected. Also, the second
The conventional technique of No. 1 has a problem that it is not possible to measure the three-dimensional position and orientation of the moving body as in the first conventional technique.

Therefore, an object of the present invention is to perform an optical measurement capable of always accurately measuring a three-dimensional positional relationship between a measurement target position provided with a light source station and a measurement reference position provided with a reflection station. It is to provide a system.

Another object of the present invention is to provide an optical measuring system capable of always accurately measuring the three-dimensional position and orientation of a moving body even if the moving body is tilted or moves up and down.

[0009]

An optical measuring system according to a first aspect of the present invention measures a three-dimensional positional relationship between a light source station and a plurality of reflecting stations arranged at positions distant from the light source station. In the system, each reflection station includes a retroreflector that reflects the incident light in the original direction, and the light source station has a first tilt angle and a second tilt angle with respect to a reference plane belonging to the light source station. Rotary scanning means for rotationally scanning the planar first and second light beams parallel to the reference plane;
And reflected light detecting means for detecting reflected light from each reflecting station in response to the second light beam, and rotation of the first and second light beams when a detection output is obtained from the reflected light detecting means. 3 between the light source station and the reflection station based on the angle detection means for detecting the scanning angle, and the rotation scanning angle detected by the angle detection means and the respective inclination angles of the first and second light beams. And a calculation means for calculating a dimensional positional relationship.

An optical measurement system according to a second aspect is the optical measurement system according to the first aspect, further characterized by the following. That is, in the optical measurement system according to the second aspect, the light source station is provided in the moving body, and the reflection stations are provided in the plurality of fixed objects arranged at different fixed positions.

An optical measurement system according to a third aspect is the optical measurement system according to the second aspect, further characterized by the following. That is, in the optical measurement system according to claim 3, the absolute coordinate position of each fixed object is known in advance,
The calculating means calculates the absolute value of the moving body in the three-dimensional space based on the rotational scanning angle detected by the angle detecting means, the inclination angles of the first and second light beams, and the absolute coordinate positions of the fixed objects. The coordinate position and the tilt angle of the moving body with respect to the absolute reference plane are calculated.

An optical measurement system according to a fourth aspect is the optical measurement system according to the first aspect, further characterized by the following. That is, in the optical measurement system according to claim 4, the light source station is provided in the main moving body, each reflecting station is provided in each of the plurality of sub moving bodies moving around the main moving body, and the computing means is The three-dimensional positional relationship of the main moving body with respect to each sub moving body is calculated.

[0013]

In the invention according to claim 1, the first and second planar light beams having the first and second inclination angles with respect to the reference plane belonging to the light source station are rotated parallel to the reference plane. The rotational scanning angle detected by detecting the rotational scanning angle of the first or second light beam when scanning and detecting the reflected light from each reflection station that responds to the first or second optical beam Based on and the respective inclination angles of the first and second light beams, the three-dimensional positional relationship between the light source station and the reflection station is calculated.

In the invention according to claim 2, the light source station is provided on the moving body, and each reflection station is provided on a plurality of fixed objects arranged at different fixed positions. Therefore, the three-dimensional positional relationship between the moving body and the fixed object is calculated.

According to the third aspect of the invention, the three-dimensional structure is obtained based on the rotational scanning angle detected by the angle detecting means, the inclination angles of the first and second light beams, and the absolute coordinate positions of the fixed objects. The absolute coordinate position of the moving body in the space and the tilt angle of the moving body with respect to the absolute reference plane are calculated.

In the invention according to claim 4, the light source station is provided in the main moving body, and each reflection station is provided in each of the plurality of sub moving bodies moving around the main moving body. Therefore, the calculation means calculates the three-dimensional positional relationship of the main moving body with respect to each sub moving body.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. Before describing specific configurations and operations, measurement principles of embodiments described later will be described with reference to FIGS. explain. In the optical measurement system according to the present embodiment, as shown in FIG. 1, for example, a plurality of retroreflectors CC are arranged around the traveling course 2 of the moving body 1 at arbitrary intervals. Each retroreflector CC has an optical property of emitting reflected light at the same emission angle as the incident angle regardless of the incident angle of the incident light. Further, two planar light beams (hereinafter referred to as planar beams) are emitted from the moving body 1 in order to detect the retroreflector CC.

(1) Object of measurement in the present embodiment Referring to FIG. 7, in the fixed Cartesian coordinate system O-XYZ,
The origin position of the moving body coordinate system o-xyz and the displacement angle of each axis are the position (X _P , Y _P , Z _P ) and the posture (Ψ, Θ,) of the moving body in the fixed Cartesian coordinate system O-XYZ, respectively.
Φ) is shown. Further, the point C _i is a fixed rectangular coordinate system O.
The coordinates (X _ci , Y _ci , Z _ci ) of the i-th retroreflector CC in −XYZ are shown. In the present embodiment, the position of the moving body in the fixed Cartesian coordinate system O-XYZ (X _P ,
Y _P , Z _P ) and the posture (Ψ, Θ, Φ).

(2) Three-dimensional position (X _P , Y _P ,
Z _P ) and attitude (Ψ, Θ, Φ) determination method Referring to FIG. 8, the position vector of the origin o of the moving body coordinate system o-xyz in the fixed Cartesian coordinate system O-XYZ is <P>.
And the rotation matrix is <R>, the fixed Cartesian coordinate system OX
The coordinate conversion between YZ and the moving body coordinate system o-xyz can be expressed by the following equation (1). <X> = <R><x> + <P> (1)

[0020] Thus, the position vector of the i-th retroreflector _{CC <C i> = [X} ci, Y ci, Z ci] to ^T, the position vectors expressed in the mobile coordinate system o-xyz <c _i> =
[X _ci , y _ci , z _ci ] ^T is expressed by the following equation (2). The symbol [] ^T indicates that the content of [] is a transposed matrix. _{<C i> = <R>} -1 (<C i> - <P>) ... (2)

Further, the position vector using a <c _i> a unit vector _{<L i><ci>} = λ i is represented with <L _i>,
Expression (2) becomes Expression (3). <R> ^-1 (<C _i >-<P>)-λ _i <L _i > = 0 (3)

However, in the equation (3), the unit vector <L _i > is <L _i > = [cos ψ _i cos θ _i , cos ψ _i sin θ _i , sin ψ _i ] ^T.

[0023] Now, the position vector of the origin o of the mobile coordinate system o-xyz <P>, using the Euler angles _{<P> = [x P,} y P, z P] is ^T, rotation matrix <R> Shall be expressed as

[0024]

[Equation 1]

Then, the equation (3) is obtained for at least three retroreflectors CC, and by rewriting it, the following equation (4) is obtained. <F (Ψ, Θ, Φ, x _P , y _P , z _P , λ ₁ , λ ₂ , λ ₃ )> = 0 (4)

Therefore, if the unit vector <L _i > is obtained, a three-dimensional position (X _P , X _P , Y _P , Z _P ) and posture (Ψ, Θ, Φ) are obtained.

Here, the Euler angle will be described with reference to FIG. Euler angles are defined by rotations Ψ, Θ, and Φ having the following three orders.

First, the X ₀ Y ₀ Z ₀ system is rotated about the Z ₀ axis so that X ₀ is included in the plane defined by Z ₀ and X ₃ . Let Ψ be the rotation angle at this time, and X ₀ Y at this position
_{The 0} Z ₀ system is named X ₁ Y ₁ Z ₁ system, and its coordinate transformation matrix is F ₁ (Ψ). Next, the X ₁ Y ₁ Z ₁ system is rotated around the Y ₁ axis so that X ₁ coincides with X ₃ , and this is set to X ₂ Y ₂ Z.
Named as system ₂ . The rotation angle at this time is Θ, and its coordinate conversion matrix is F ₂ (Θ). Finally, the X ₂ Y ₂ Z ₂ system is rotated around the X ₂ axis to match X ₃ Y ₃ Z ₃ . The rotation angle at this time is Φ, and the coordinate conversion matrix is F ₃ (Φ)
And The rotation angles Ψ, Θ, and Φ defined in this way are called Euler angles.

(3) How to obtain the observation angles θ _i and ψ _i from the moving body Referring to FIG. 10, in the moving body coordinate system o-xyz,
A plane passing through the origin o and parallel to the xz plane is α around the x axis.
Rotate by ₁ (> 0), then rotate around z-axis i
The plane containing the position C _i of the th retroreflector CC is oC _i A
_i . The rotation angle around the z axis at this time is θ _i1 .
Similarly, a plane that passes through the origin o and is parallel to the xz plane is rotated about the x axis by α ₂ (> 0), and further rotated around the z axis so that the plane including the position C _i of the i-th retroreflective CC is oC. _i
Let B _i . The rotation angle around the z-axis at this time is θ _i2 . Let D _i be the point of intersection of the foot of the perpendicular line drawn from C _i to the xy plane and the xy plane, and let θ _i , oC be the angle that oD _i makes with the x axis.
If the angle between _i and oD _i is ψ _i , θ _i and ψ _i are expressed by the following equations (5) and (6).

[0030]

[Equation 2]

The configuration and operation of one embodiment of the present invention utilizing the above principle will be described below.

FIG. 1 is a perspective view showing the overall construction of an optical measurement system according to an embodiment of the present invention. In the figure,
A plurality of retroreflectors CC are arranged at arbitrary intervals around the traveling course 2 of the moving body 1. A corner cube, for example, is used as the retroreflector. As is well known, a corner cube has three light reflecting surfaces that are orthogonal to each other and has an optical property of emitting reflected light at the same exit angle as the incident angle regardless of the incident angle of the incident light. .. That is, the reflected light follows the path of the incident light in the opposite direction and returns to the original direction.

On the other hand, a laser measuring device 3 is mounted on the moving body 1. As shown in FIG. 2, the laser measuring device 3 includes a beam emitting device 5, a rotation driving device 6, and a computing device 7. The rotary drive device 6 and the arithmetic device 7 are housed inside a housing 30. Beam launcher 5
Is a rotary plate 61 integrally formed with the rotary shaft 62.
It is mounted on the rotary body 6 and is rotated by the rotation drive device 6 along a reference plane (xy plane of the mobile body coordinate system) belonging to the mobile body 1. Therefore, the two surface beams 41 and 42 emitted from the beam emitter 5 are rotationally scanned about the rotation axis 62 in parallel with the reference plane.

The beam projecting device 5 includes two sets of light projecting / receiving units 8A and 8B having the same structure for projecting the surface beams 41 and 42 in order to detect the retroreflector CC. As shown in FIG. 3, each light emitting / receiving unit has a laser diode 81, which is an example of a light source, inside a housing 80.
, Collimating lens 82, and cylindrical lens 8
3, a condenser lens 84, and a photodiode 85, which is an example of a light receiving element, are arranged as shown in the figure. It should be noted that the light source only needs to have a sharp directivity, and a light emitting diode, a gas laser, or the like may be used instead of the laser diode 81.

The light emitted from the laser diode 81 is collimated by a collimator lens 82 and then spread in a two-dimensional direction by a cylindrical lens 83 which is tilted by a predetermined angle so as to have a predetermined spread angle and a predetermined tilt. It becomes the surface beam 41 (or 42) which it has, and it radiate | emits outside. The inclination angle of the surface beam 41 is α ₁ , and the surface beam 42
The inclination angle of is α ₂ . It should be noted that two sets of light emitting / receiving unit 8
One light emitting and receiving unit is provided instead of A and 8B,
By rotating the cylindrical lens 83, the two surface beams 41 and 42 having the inclination angles α ₁ and α ₂ may be obtained.

Surface beams 41 and 42 emitted to the outside
When it hits one of the retroreflectors CC, it becomes reflected light 43 (or 44) indicated by a dotted line, and the light emitting / receiving unit 8A
(Or 8B) respectively. This reflected light 43
(Or 44) is condensed by the condenser lens 84 and detected by the photodiode 85. Since the reflected light 43 (or 44) returns as a surface beam, the reflected light 43 (or 44) can be detected even if the photodiode 85 is arranged slightly displaced from the optical axis of the laser diode 81. ..

Next, with reference to FIGS. 4 and 5, the geometrical relationship in the three-dimensional space of the above embodiment will be described. Now, of the surface beams emitted from the beam emitter 5 in the laser measuring device 3 mounted on the moving body 1, the surface beam 41 emitted with an inclination of α ₁ is rotated within the reference plane of the moving body 1. For example, θ _i1 is obtained as the rotation angle that hits the retroreflector CC, and if the surface beam 42 that is emitted with an inclination of α ₂ is rotated within the reference plane of the moving body 1, θ _i2 is obtained as the rotation angle that hits the retroreflector CC. Be done. Therefore, by substituting these θ _i1 and θ _i2 into the above equations (5) and (6), the observation angles θ _i and ψ _i from the moving body 1 can be obtained. If this observation angle measurement operation is performed on at least three retroreflectors CC, the three-dimensional position (three-dimensional position in the fixed coordinate system O-XYZ) of the center of rotation of the surface beam can be calculated from the equation (4). Position) and attitude are required.

Next, the configuration of the electric circuit portion of the above embodiment will be described with reference to FIG. In the figure, the beam emitter 5 is provided with two sets of light emitting / receiving units 8A and 8B. Each of the light emitting / receiving units 8A and 8B includes a laser diode 810, 811 and a photodiode 82.
0,821. The arithmetic unit 7 is a laser diode 8
Driving circuits 710 and 71 for causing 10, 811 to emit light
1 and amplifiers 720 and 721 for amplifying the outputs of the photodiodes 820 and 821, respectively, and an amplifier 72.
Waveform shaping circuits 730 and 731 for shaping the waveforms of the outputs 0 and 721, respectively, and a device that is provided in the rotary drive device 6 and generates a pulse according to the rotation angle, for example, a counter that counts the pulses from the rotary encoder 63. 740, a CPU 760 that calculates the three-dimensional position and orientation of the moving body 1, and an interface 750 that transfers angle data to the CPU 760. The CPU7
Reference numeral 60 is connected to the external storage device 9. The external storage device 9 stores an operation program for the CPU 760.

Next, the operation of the above embodiment will be described. Now, the rotation reference position of the rotary encoder 63 and the emitting direction of the surface beam 41 from the light emitting / receiving unit 8A are aligned, and the surface beam 41 is moved in the positive direction of the x-axis of the moving body coordinate system.
The counter 740 turns the rotary encoder 63 when
Shall be reset by a reset signal from.
When the light emitting / receiving units 8A and 8B are rotated by the rotation driving device 6 along the reference plane belonging to the moving body 1, the rotation shaft 6 is rotated.
A pulse is output from the rotary encoder 63 in synchronization with the rotation of 2. This pulse is counted by the counter 740. When the surface beam 41 hits the retroreflector CC,
The reflected light 43 is detected by the photodiode 820. The detection signal of the photodiode 820 is supplied to the amplifier 72.
It is sent to the counter 740 as a latch signal via 0 and the waveform shaping circuit 730. Counter 740 at this time
The count data, that is, the angle data of the
It is sent to the CPU 760 together with the light reception determination signal via 50. A similar operation is the same for at least three retroreflectors CC
For each surface beam.

Next, the CPU 760 substitutes the angle data θ _i1 , θ _i2 (i = 1, 2, 3) obtained as described above into the above equations (5) and (6) to observe angle θ. _i and ψ _i (i =
1, 2, 3) is calculated. Next, the CPU 760 substitutes the calculated observation angles θ _i and ψ _i (i = 1, 2, 3) into the above equation (4) to calculate the three-dimensional position of the moving body in the moving body coordinate system o-xyz. (X _P , y _P , z _P ) and posture (Ψ,
Calculate Θ, Φ). Further, using the equation (1), the position (X _P ,
Y _P, Z _P) and attitude (Ψ, Θ, Φ) is calculated.

In the above embodiments, the vehicle running on the road is shown as an example of the moving body, but the present invention is also applied to the position measurement and attitude measurement of a ship moving on the water or an aircraft moving in the air. Is possible.

In the above embodiment, the retroreflector is provided at a fixed position. However, for example, the retroreflector may be provided on a plurality of sub-moving bodies that move in a formation with the main moving body. .. In this case, the three-dimensional positional relationship and orientation between the main moving body and each sub moving body can be measured.

[0043]

According to the invention of claim 1, it is possible to accurately measure the three-dimensional positional relationship between the light source station and the reflection station.

According to the second aspect of the invention, it is possible to accurately measure the three-dimensional positional relationship between the moving body and the fixed object.

According to the invention of claim 3, it is possible to measure the absolute coordinate position of the moving body in the three-dimensional space and the tilt angle of the moving body with respect to the absolute reference plane. Therefore,
Accurate measurement of position and posture is possible regardless of the inclination or vertical movement of the moving body.

According to the invention of claim 4, for example, it is possible to accurately measure the three-dimensional positional relationship between the main moving body and the sub moving body moving in a formation.

[Brief description of drawings]

FIG. 1 is a perspective view showing an overall configuration of an optical measurement system according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing the configuration of a laser measuring device mounted on the moving body in FIG.

FIG. 3 is a partially cutaway perspective view showing a configuration of a light emitting / receiving unit mounted on the beam emitter shown in FIG.

FIG. 4 is an illustrative view showing a geometrical relationship in a three-dimensional space between a moving body and a retroreflector in the embodiment shown in FIG.

5 is an illustrative view showing a geometrical relationship in a three-dimensional space between a moving body and a retroreflector in the embodiment shown in FIG. 1. FIG.

FIG. 6 is a block diagram showing a configuration of an electric circuit portion according to an embodiment of the present invention.

FIG. 7 is a geometrical schematic diagram showing a relationship between a fixed coordinate system and a moving body coordinate system.

FIG. 8 is a geometrical schematic diagram showing the relationship between a fixed coordinate system and a moving body coordinate system.

FIG. 9 is a geometrical schematic diagram for explaining Euler angles.

FIG. 10 is a geometrical schematic diagram showing an observation angle of a retroreflector to be measured by a moving body in the embodiment shown in FIG.

[Explanation of symbols]

CC: Retroreflector 1: Moving body 2: Traveling course 3: Laser measuring device 5: Beam emitting device 6: Rotation drive device 7: Computing device 8A, 8A: Emitter / receiver unit 41: α ₁ inclined surface beam 42: α ₂ Inclined surface beam 63: Rotary encoder

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenichi Nishide 1-35-1 Izumihonmachi, Komae-shi, Tokyo Within Tokyo Aircraft Instrument Co., Ltd. No. 35-1 Tokio Aviation Instrument Co., Ltd.

Claims (4)

[Claims] 1. An optical measurement system for measuring a three-dimensional positional relationship between a light source station and a plurality of reflection stations arranged at positions distant from the light source station, wherein each of the reflection stations has an incident angle. The light source station includes a retroreflector that reflects the reflected light in the original direction, and the light source station has first and second planar surfaces having first and second inclination angles with respect to a reference plane belonging to the light source station. Rotation scanning means for rotationally scanning the optical beam of the laser beam parallel to the reference plane, and reflected light detection means for detecting the reflected light from each of the reflection stations in response to the first and second light beams. An angle detection means for detecting a rotation scanning angle of the first and second light beams when a detection output is obtained from the reflected light detection means, and a rotation scanning angle detected by the angle detection means. And each tilt of the first and second light beams Based on the bevel angle and
An optical measurement system, comprising: a calculation unit for calculating a three-dimensional positional relationship between the light source station and the reflection station. 2. The optical measurement system according to claim 1, wherein the light source station is provided in a moving body, and each of the reflection stations is provided in a plurality of fixed objects arranged at different fixed positions. 3. The absolute coordinate position of each of the fixed objects is known in advance, and the arithmetic means includes the rotational scanning angle detected by the angle detection means and the inclination angles of the first and second light beams. The light according to claim 2, wherein an absolute coordinate position of the moving body in a three-dimensional space and an inclination angle of the moving body with respect to an absolute reference plane are calculated based on and the absolute coordinate position of each of the fixed objects. Measuring system. 4. The light source station is provided in a main moving body, each of the reflecting stations is provided in a plurality of sub-moving bodies that move around the main moving body, and the computing means is provided in each of the sub-moving bodies. The optical measurement system according to claim 1, which calculates a three-dimensional positional relationship of the main moving body with respect to the moving body.