JPH02306108A - Recognizing apparatus for three-dimensional position - Google Patents

Abstract

PURPOSE:To shorten the time for recognizing a three-dimensional position and to scan light beams at higher speeds by turning ON a plurality of light emitting points of a light source in a time-sharing manner thereby to scan light beams in a one-dimensional and then in a second-dimensional manners. CONSTITUTION:When light emitting points of a light source 11 are turned ON in a time-sharing manner in synchronization with the movement of a mirror 18, an aligned pattern is drawn on an object 13 to be measured. The reflecting light from the object 13 is collected by receiving lenses 14,15 placed symmetric to each other with a distance measuring axis (Z axis) at the center, and radiated onto each receiving surface of receiving elements 16,17 which are similarly placed symmetric to each other with the Z axis at the center. The distance to each illuminating point on the object 13 is operated based on output signals from the elements 16,17 obtained corresponding to the collecting point on the received surface. A scanning angle to an X axis and a Y axis of the light beams projected onto the object 13 from the mirror 18 is found from scanning signals to a movable coil 19. Accordingly, a three-dimensional position of the object can be known from the scanning angle and the distance to the object 13.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention utilizes reflected light from an object to be measured. #1 This relates to a three-dimensional position recognition device that recognizes the position of a fixed object in three dimensions.

[Conventional technology]

FIG. 6 shows the optical system of a typical distance detector.

The luminous flux of the light source 1 is focused and irradiated onto the object 3 by the light projecting lens 2, and the reflected light is focused by the light receiving lens 4 onto the light receiving element 5 for position detection.

Here, the distance from the light-receiving lens 4 to the object 3 to be illuminated is L1, the base line length is B, and the distance between the light-receiving lens 4 and the light-receiving element 5 for position detection is
The distance X from the center of the optical axis of the light-receiving lens 4 to the center of gravity of the snoring light is expressed by the following equation (1).

x −' f ・B/L'
...(1) Light receiving element for position detection 5. By finding the distance X in equation (1) that indicates the displaced position, the distance can be found conversely. In addition, the distance detector was mechanically moved on a plane perpendicular to the plane of the figure and including the base line length and direction, and the position of the distance detector on this two-dimensional plane (X, Y
) and the variable position X obtained from the position detection light receiving element 5, the distance in the Z-axis direction is determined, and the three-dimensional position (X, Y, Z) is recognized.

[Problem to be solved by the invention]

However, in the conventional three-dimensional position recognition device described above, the distance detector itself must be mechanically moved on the (X, Y) plane. Therefore, it takes a long time for one total DI for three-dimensional position recognition. For this reason, conventional devices can be applied to 3D position recognition for static JPI objects, but cannot be practically applied to 3D position recognition for dynamic objects. The problem was that it was not possible.

Therefore, an object of the present invention is to provide a three-dimensional position recognition device that can recognize the three-dimensional position of a dynamic object.

[Means to solve the problem]

A three-dimensional position recognition device according to the present invention includes: a light source in which a plurality of light emitting points are arranged in a straight line and driven to turn on pulses in a time-division manner; a light projecting means for condensing a luminous flux emitted from each light emitting point;
A scanning means scans in synchronization with the pulse lighting drive of the light source, deflects the light flux from the light projecting means, and irradiates it onto the object to be measured, a light receiving means that collects the reflected light from the object to be measured, and a light receiving means that focuses the reflected light from the object to be measured. a light receiving element for position detection that detects the condensing position of the light flux, and a calculation means that calculates the distance to the irradiation point of the light flux focused on the object to be measured based on the output signal of the light receiving element for position detection. It is characterized by:

[Effect]

According to the present invention, the luminous flux emitted from the light source is one-dimensionally scanned by driving a plurality of light-emitting points in a time-division pulse lighting manner, and is deflected by the scanning means in a direction perpendicular to the arrangement direction of the light-emitting points. Two-dimensional scanning is performed by scanning.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a grid according to an embodiment of the present invention, and each three-dimensional direction is (x, y) in the figure.

Z) is determined by each direction shown in the coordinates.

The light source 11 has nine light emitting points from Ω to l119, ■ Each light emitting point is arranged linearly in the X-axis direction.

Note that the number is set to nine for the purpose of simplifying the drawing, and the number is not necessarily limited to this number. The projection lens 12 is installed in such a way that its optical axis coincides with the center of the light emitting point Ω5 located at the center of the nine light emitting points, and the luminous flux from each light emitting point is projected onto the constant object 13. The light is focused.

The mirror 18 and the galvanometer 9 are connected to the projection lens 12
When the object to be measured 13 is irradiated with the luminous flux from the light emitting point Ω
It is used as a scanning means for scanning in a direction perpendicular to the arrangement direction of J79, that is, in the Y-axis direction. That is, the rotation axis of the galvanometer 9 is installed to coincide with the X-axis direction, and when the mirror 18 fixed to the rotation axis of the galvanometer 19 is rotated in the direction shown by the arrow in the figure, the object 13 to be irradiated is irradiated. The emitted light beam is scanned in the Y-axis direction.

Note that the axis along which the optical axis of the light projecting lens 12 is deflected by 90 degrees coincides with the Z axis, and will hereinafter be referred to as the distance detection axis.

When each light emitting point of the light source 1 is time-divisionally illuminated in pulses in synchronization with the movement of the mirror 18, the aligned irradiation pattern shown in the figure is drawn on the object to be measured 13. Subject δp1 constant 13
The reflected light is focused by a pair of light-receiving lenses 14 and 15 arranged symmetrically around the distance detection axis (Z-axis), and a pair of light-receiving lenses 14 and 15 arranged symmetrically around the distance detection axis as well. The light is irradiated onto each light receiving surface of the position detection light receiving elements 16 and 17. The distance (L
) is calculated by a calculation means (not shown) which will be described in detail later. Furthermore, the scanning angle (θ, θ) of the light beam irradiated from the mirror 18 onto the object 13 with respect to the X-axis and Y-axis can be determined from the scanning signal sent to the galvanometer 19, and this scanning angle Three-dimensional position recognition becomes possible from this and the distance (L) to all fixed objects 13.

FIG. 2 is a configuration diagram of a general semiconductor device detector used for the position detection light receiving elements 16 and 17. As this semiconductor device detector, for example, there is a one-dimensional semiconductor device detector manufactured by Hamamatsu Photonics Co., Ltd. with a model name of 81662, and the case where this semiconductor device detector is used will be described below.

The semiconductor device detector 25 includes an n-type semiconductor layer 27, a high-resistance n-type semiconductor layer 28, and an n-type semiconductor layer 2 with uniform resistivity.
9 are sequentially laminated. n
type semiconductor layer 28 and n-type semiconductor layer 29 constitute a photodiode.

Further, the n+ type ring conductor layer 27 is provided with a common electrode 30 for applying a reverse bias voltage to the photodiode, and a pair of electrodes 31 .
32 are provided.

When a predetermined voltage is applied to the common electrode 30 of the semiconductor device detector 25 and a light spot is incident on the position SP, an electron-hole pair is generated at the pn junction below the position SP. The photocurrent 1 proportional to the incident energy of the light spot is
o flows from the common electrode 30 toward the n-type semiconductor layer 29.

Here, let the distance between the electrodes 31 and 32 be 01, the resistance of the n-type semiconductor layer 29 between them be R8, and the distance between the light spot incident position SP and the electrode 32 be Xl, and the resistance of the n-type semiconductor layer 29 between them be When R, the photocurrent Io is resistance-divided at the light spot incident position SP.

That is, the current IA to the electrode 31 and the current IB to the electrode 32 are each expressed by the following equations.

1 -1 ・[R/Ro] A Ox I -I -[(Rc -Rx)/R
o]-(2)O Furthermore, as described above, since the resistivity of the n-type semiconductor layer 29 is uniformly distributed, this equation (2) can be modified as follows.

1-1-xIC O 1-1・[(C-x)/C]...(3)
As can be seen from equation (3), the currents I and I are taken out from the B electrodes 31 and 32, and are subjected to predetermined analog calculation processing by the calculation means described later.
2 to the light spot incident position SP can be determined.

3 and 4 are diagrams for explaining the principle of distance detection in an optical system using the three-dimensional position recognition device according to this embodiment. ) It is a view seen from above. Note that in order to simplify the drawing, the means for scanning the irradiation light beam in the Y-axis direction is omitted from the diagram.
Further, the optical axis of the light projecting lens 12 and the distance detection axis (Z-axis) are shown in alignment. Further, in the position detection light receiving elements 16 and 17, the electrodes 31 on the optical axis side (inside) and the opposite side (outside) of the light emitting lens 12 are connected to each other, and the common electrodes are also connected to each other. There is.

For this reason, a predetermined bias voltage (Bias) is applied to the common electrode.
is applied and spot light is focused on each light receiving surface of the light receiving elements 16 and 17, so that photocurrents 1 and I containing position information are obtained at each B connection.

FIG. 3 is a diagram showing the principle of distance detection when the light emitting point g5 among the light emitting points (1-119) of the light source 11 is pulse-lit.

Here, the distance from the distance detector to the object to be measured 13 is L
1. Let LN be the distance when the object to be measured is moved to the position indicated by the two-dot chain line 13'. In addition, each interval between the optical axis of the light emitting lens 12 and each optical axis of the pair of light receiving lenses 14 and 15 is B1.
From the light receiving lens 14°15 to the light receiving element 16.1 for position detection
Let the interval up to 7 be f. In addition, the light receiving lens 14.15
The X1 object to be measured 13 is the distance from the optical axis of the object to each condensing position of the reflected light from the object to be measured 13 on the light-receiving surface of the position detection light-receiving element 16,17. Let ΔX and ΔX2 respectively be the amount of movement of the light condensing position on each light receiving surface when the beam is moved by a distance MLN.

■ At this time, the following relational expressions (4) to (6) hold between each factor.

X-f-B/Lo...(4)
X+Δx1-x+Δx2-f-B/LN...(5)Δ
X1-Δx2-f-B (1/LN-1/Lo)-= (6) Therefore, X, ΔX i from the photocurrent values I and IB obtained from the position detection light receiving element 16.17.

^ By finding the value of ΔX2, the object to be measured 13.1
It is possible to find the distances L and L up to 3'. The object to be measured 13 is at a distance. Adjust the position at which the irradiated light beam is focused on each light receiving surface when the light is in the position to match the electrical center position of each position detection light receiving element 16. If you keep it, A11
l constant 13 gari. If the light receiving elements 16 and 17 are located at a closer distance, the light collecting position of the position detection light receiving elements 16 and 17 moves to the outside of the electrical center position (to the side opposite to the optical axis direction of the light projecting lens 12). On the contrary, the δp1 constant 13 rises. If the light is located at a longer distance, the light condensing position moves to the inside of the electrical center position (toward the optical axis side of the light projecting lens 12). Here, when the moving direction of the focused spot light goes outward, it is defined as plus (+), and when it moves inward, it is defined as minus (-).

FIG. 4 is a diagram showing the principle of distance detection when the light emitting point g1 among the light emitting points 1)-D9 of the light source 11 is pulse-lit.

In this case, the light emitting point Ω1 is located 6 g apart from the optical axis of the light projection lens 12 at the upper side of the figure, so the irradiation position on the m ApJ constant object 13 is below the optical axis of the light projection lens 12. become. Here, when the object to be measured 13 exists at a distance Lo, the light condensing position on each light receiving surface of the position detection light receiving element 16.17 is determined by the electrical The positions are respectively X IN2 away from the center position. Also, the object to be measured 13 is LN indicated by a two-dot chain line 13'.
, the focal point of the spot light is X1+X
The positions are shifted by ΔX and ΔX2 from the positions of 2 and 2, respectively.

The relationship between the distance and the amount of displacement in the position detection light receiving element 16 is calculated as follows.

x + X 1 -f-(B-14#Δg @Lo/f)/L.

■ -(f-B+Δff-L)/L...
'C7)
IN N From these equations (7) and (8), the following equation (9) holds true.

Δx −(f−B+6g−LN)/LN−(f−B
+6g・L)/L.

-f-B (1/LN-1/Lo) (9) Next,
Similarly, the relational expression between the distance and the amount of displacement in the position detection light-receiving cable 17 is determined as follows.

-x2 -f・　(B-6g　-L　/f)/L.

-(f-B-Δ(1-L)/L...(10
)x-x2+Δx2-f・(B-6g・L/f)/LNN-(f-B-Δ(1-L)/L...(11
)IN N From these equations (10) and (11), the following equation (12) holds true.

ΔX −(f*B−ΔN−LN)/LN−(f
ψB-6g YuLo)/L.

-f-B (1/LN-1/Lo) ... (12) In equations (lO) and (11), minus (
-) The reason for the presence of the sign is that xl is located outside the electrical center position of the position detection light receiving element 16, while x2
This is because it is located inside the electrical center position of the position detection light receiving element 17. Furthermore, the above equations (9) and (12) match equation (6) found in FIG. Therefore, it can be seen that the light emitting point g5 of the light source 11 has the same amount of displacement as when the pulse light is turned on.

Similarly, when the relationship between the distance when the other light emitting points g2 to Ω4 and the light emitting points g6 to g9 of the light source 11 are pulsed and the displacement of the spot light is found, all of them match equation (6). become. That is, the number of light emitting points N, -i of the light source 11 is
No matter which light emitting point at t9 is pulsed, the distance M
, L, the displacement amounts ΔX and Δx2 of the spot light focused on the position detection light receiving element 16.17 have the same value.

■ In other words, a pair of position detection light receiving elements 16 and 17
By making a predetermined connection using a pair of one-dimensional semiconductor device detectors, the generated photocurrent 1, I
The signal calculation values indicating the distance to the object to be measured 13 calculated from B as will be described later become the same numerical value. This value is based on 9 light emitting points Ω placed on a straight line.
~ Regardless of which light emitting point in Ω9 is pulse-lit, the light irradiated from the light source 11 is aligned with the distance detection axis (
The same is true when irradiating a plane (X, Y plane) perpendicular to the Z axis).

Furthermore, even if the light beam is scanned in the Y-axis direction, there should be no change in the displacement amounts Δx1 and Δx2 in the X-axis direction of the spot light focused on the light-receiving surfaces of the position detection light-receiving probes 16 and 17. is clear.

Therefore, the signal calculation value indicating the distance to the AB target ΔIII constant object 13 calculated from the generated photoelectricity Rx,I is Y
Even if the light beam is scanned in the axial direction, the same numerical value can be obtained if the light beam is irradiated on the (X-Y) plane.

FIG. 5 is a block diagram of a signal processing circuit, which is the calculation means used in this embodiment.

Nine light emitting diodes LED-LED9 are used for the nine light emitting points Ω to g9 of the light source 11, and these are driven by drive signals D1 to D from the LED drive circuit U13.
9, pulse lighting is performed in a time-division manner. These pulse lighting operations are performed based on a lighting command from the timing controller U12. At the same time, a scanning command signal is also sent to the Y-axis scanning drive circuit U14 of the galvanometer 9, so that the mirror 18 provided in the galvanometer 9
is rotated, and the light beam is scanned in the Y-axis direction in synchronization with the lighting operation of the LED. In addition, light emitting diodes LED1 to LE
The number of scans in the X-axis direction in the measurement field of view is determined by how many times the series of time-division pulse lighting operations D9 is repeated for one Y-axis scan.

The photocurrent ■ and IB obtained in the position detection photodetector 16 and 17 are current-voltage conversion resistance rt+r
is converted into voltage signals v, v', and
The DC (direct current) component is removed by the AB capacitors C and C2, and only the AC (alternating current) component is sent to the amplifier circuit U1. -U
2 and amplified. After this, the amplifier circuits U and U are offset by capacitors C and C.
The amount of deviation in DC potential due to l 2 drop and temperature drift is cut. Then, only the amplified AC component is sent to the subtraction circuit U and addition circuit U4, and V −■ and V
The calculations A+VB are performed in real B respectively.

Each calculation signal is sent to sample-and-hold circuits U5 to U, where it is sampled based on sampling signals S and S given from timing controller U12, and the signal level is held. That is, the sampling signal S1 samples the potential immediately before each light emitting point turns on in a pulse, and the sample and hold circuit U
, recorded in U. On the other hand, the sampling signal S2 samples the potential in the state where each light emitting point is lit in pulses, and the sample and hold circuit U
, recorded in U.

The subtraction circuit U 1 subtracts the output value of the circuit U 2 from the output value of the circuit U 6 , and the subtraction circuit U 1 o subtracts the output value of the circuit U 7 from the output value of the circuit U 2 .

As a result, only the signal component caused by the pulsed lighting of the light source 11 is extracted. Then, in the analog divider U11, an arithmetic process of (VA-VB)/(V+VB) is executed.

This calculation result is output to the outside and corresponds to the distance fiL from the distance detector to the object to be measured 13, and becomes Z component data in three-dimensional position recognition. Also, in synchronization with the output of analog divider U1□, he? The polarization angle of the light beam irradiated onto the I-1 constant object 13 is separated into an X-axis component (θ) and a Y-axis component (θ).
The data is output from the y-timing controller U12 to the outside, and becomes X component data and Y component data in three-dimensional position recognition. The X component data is based on the drive signal for pulse lighting of the light source 11, and the Y component data is based on the scanning signal of the galvanometer 9.

Here, if the origin of the Z-axis is set at the rear principal point position (not shown) of the projection lens 12, the distance ML to the target Δp1 constant object 13
can be easily determined from the output of the analog divider U1. Therefore, the three-dimensional position data (X, Y, Z) representing the irradiation point of the light beam focused on the object to be measured 13 is obtained from the two declination angles θ and θ as follows (13) to (15) below y. It can be determined using the formula.

Z-L...(13)Y
=L-tanθ, -(14)X=L-t
anθ, −(15) As described above, according to this embodiment, the nine light emitting points g −Ω9 are time-divisionally pulsed driven, so that 1 A dimensional scan is performed, and another one-dimensional scan is performed using a mirror 18 with good followability and a galvanometer 9, so that the light beam emitted from the light source 11 is subjected to a two-dimensional scan.Therefore, The scanning of the light beam is performed with good responsiveness and becomes faster, and the measurement time required for one three-dimensional position recognition is shortened, and the measurement time is reduced by more than two orders of magnitude compared to the conventional method.As a result,
The apparatus according to this embodiment can also be applied to three-dimensional position recognition for a dynamic ΔIII constant object.

In addition, in the description of the above embodiment, a pair of light receiving lenses 14.15 and a pair of position detection light receiving elements 16.17 are used.
Although the explanation is made using the above example, there is no need to be limited to this, and for example, the structure may be constructed using only one light receiving lens and one position detection light receiving element, and the same effect as the above embodiment can be obtained. play. However, in this case, the calculation of the distance to the yδ-1 constant becomes complicated, and the calculation time takes a little longer. Therefore, the apparatus having the configuration of the above embodiment is more suitable for a dynamic object to be measured that moves at a higher speed.

〔Effect of the invention〕

As described above in detail, according to the present invention, the luminous flux emitted from the light source is one-dimensionally scanned by driving a plurality of light-emitting points in a time-division pulse lighting manner. Two-dimensional scanning is performed by deflection scanning in a direction perpendicular to the arrangement direction. Therefore, the scanning performance of the light beam emitted from the light source is increased, and the time required for three-dimensional position recognition is shortened. As a result, conventionally, 3
This has the effect of providing an apparatus that can target dynamic objects to be measured whose dimensional position recognition has been difficult.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the configuration of an embodiment of the present invention, FIG. 2 is a diagram showing a semiconductor device detector used in the device shown in FIG. 1, and FIG. FIG. 4 is a diagram for explaining the principle of distance detection when the light emitting point Ω5 emits light in the device shown in FIG. 5 is a block diagram showing a signal processing circuit used in the apparatus shown in FIG. 1, and FIG. 6 is a diagram showing a general distance detector. 11... Light source, 12... Light projecting lens, 13... Measured object, 14.15... Light receiving lens, 16.17...
・Position detection light receiving element, 18...Mirror, 19...
galvanometer. Representative patent attorney Yoshiki Hase X 7R' of invention
fkΣshow T bell 4 breast diagram No. 1 figure lead dominant word search: instrument Tatsumi: figure one crown': J-゛ distance IX great = instrument No. 6 figure procedure amendment 1 case presentation 1999 Patent Application No. 126257 2 Name of the invention 3-dimensional position recognition device 3 Relationship with the person making the amendment Patent applicant Hamamatsu Photonics Co., Ltd. 4 Agent (Postal code 101) U-Y Building, 2-7-9 Higashikanda, Chiyoda-ku, Tokyo 4th Floor 5 The "Claims" and "Detailed Description of the Invention" of the specification to be amended, and 6. Contents of the amendment (1) The claims of the specification shall be amended as shown in the attached sheet. (2) Change the “luminous flux of light source 1” on page 2, line 8 of the specification to “
The light beam emitted from light source 1 is corrected. (3) Specification, page 4, line 2, line 4, line 6, line 9, and line 12, page 5, line 9, line 12, and line 19, page 6, line 16,
Page 15, lines 7 and 13, Page 16, lines 7, Page 18, lines 7 and 19, Page 19, lines 12 and 13, and Page 20, lines 11.
Correct the "luminous flux" of rows and 16 rows to "light beams". (4) On page 5, line 11 of the specification, “mirror 18 and galvanometer 19” has been changed to “mirror 18 and movable coil 19.”
constitutes a galvanometer, and this galvanometer corrects to . (5) Specification page 5, lines 15 and 16-17, page 6, lines 17-18, page 16, lines 4 and 5-6, page 18, lines 13
Correct "galvanometer" in line 10 of page 19 to "moving coil". (6) Correct the "irradiation light flux" on page 9, line 5 of the specification and page 11, line 3 to "light beam." (7) Correct "Garno Kunometer" on page 21, lines 14-15 of the specification to "movable coil." The above claims include a light source in which a plurality of light emitting points are arranged in a straight line and driven to turn on pulses in a time-division manner; a light projection means for condensing a light beam emitted from each of the light emitting points; scanning means that scans in synchronization with the lighting drive and deflects the light beam from the light projecting means in a direction perpendicular to the arrangement direction of the light emitting points of the light source and irradiates the object to be measured; a light-receiving means for condensing the reflected light; a position-detecting light-receiving element for detecting the condensing position of the light beam condensed by the light-receiving means;
A three-dimensional position recognition device comprising: calculation means for calculating the distance to the irradiation point of the light beam focused on the object to be measured based on the output signal of the position detection light receiving element.

Claims (1)

[Claims] A light source in which a plurality of light emitting points are linearly arranged and driven to turn on the pulses in a time-division manner, a light projecting means for condensing the luminous flux emitted from each of the light emitting points, and scanning in synchronization with the pulse lighting driving of the light source. scanning means for deflecting the light beam from the light projecting means in a direction perpendicular to the arrangement direction of the light emitting points of the light source and irradiating it onto the object to be measured; and a light receiving means for condensing the reflected light from the object to be measured. a position detection light receiving element for detecting the condensing position of the light beam focused by the light receiving means; and an irradiation point of the light beam focused on the object to be measured based on the output signal of the position detection light receiving element. A three-dimensional position recognition device comprising a calculation means for calculating a distance to.