JPH02306109A - Recognizing apparatus for three-dimensional position - Google Patents

Abstract

PURPOSE:To perform scanning with light beams at a higher speed and to shorten the time for recognizing a three-dimensional position by sequentially and time- sharingly turning ON light emitting points provided in a two-dimensional manner thereby to perform scanning with the light beams emitted from a light source in a two-dimensional manner. CONSTITUTION:As a photodiode 20 of a light source 11 is sequentially turned ON from points l1.1 to l9.5 in a time-sharing manner, an illuminating pattern is drawn onto an object 13 to be measured. The reflecting light from the object 13 is received by receiving lenses 14,15 provided symmetric to each other center ing a Z axis and, the converged light beam is applied to photodetectors 16,17 for detecting the position of the object. The receiving elements 16,17 generate output signals corresponding to the position of convergence of the light beam. Then, the output signals are input to an operating means, where the distance to each illuminating point on the object 13 is operated. Furthermore, a scanning angle of the light beams onto the object 13 from a projecting lens 12 to an X and a Y axes is found out from driving signals which turn ON the light source 11. Accordingly, the 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 [Field of Industrial Application] The present invention relates to a three-dimensional position recognition device that recognizes the position of a measured object in three dimensions using reflected light from the measured object.

[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 to be measured 3 is L1
When the base line length is 81 and the distance between the light receiving lens 4 and the position detection light receiving element 5 is f, the distance X from the optical axis center of the light receiving lens 4 to the center of gravity of the spot light is expressed by the following equation (1).

x-f-B/L...(1
) By using the position detection light-receiving element 5 to find X in equation (1), which indicates the displacement, the distance can be found conversely. In addition, the distance detector is mechanically moved on a plane that is perpendicular to the plane of the figure and includes the base line length direction, and the position (X, Y) of the distance detector on this two-dimensional plane and the distance from the position detection light receiving element 5 are measured. From the obtained displacement position X, the distance 1j in the Z-axis direction
iffiL was determined, and the three-dimensional position of (X, Y, Z) was 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 to perform one measurement for three-dimensional position recognition. For this reason, conventional devices can be applied to 3D position recognition for static objects to be measured, but cannot be practically applied to 3D position recognition for dynamic objects to be measured. There was a problem that I couldn't do it.

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

[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 two-dimensionally arranged and driven to turn on pulses in a time-division manner;
a light projecting means for condensing a luminous flux from a light emitting point and irradiating it onto an object to be measured; a light receiving means for condensing reflected light from the object to be measured;
Calculates the distance to the irradiation point of the focused light on the object to be measured based on the position detection light receiving element that detects the focusing position of the light beam focused by the light receiving means and the output signal of the position detection light receiving element. The invention is characterized in that it includes an arithmetic device that performs the following operations.

[Effect]

According to the present invention, the luminous flux emitted from the light source is two-dimensionally scanned by driving the two-dimensionally arranged light emitting points sequentially in a time-division manner with pulse lighting.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a configuration 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 includes gx5 (45) light emitting diodes 20, 9x5 (45) optical fibers 19 that propagate the light emitted from the light emitting diodes 20, and each optical fiber 1.
Light emitting points l t,t are two-dimensionally arranged in 9 columns and 5 rows on the end face of the output side of 9.

Ω,...,F,,llll,...
・・g) 2.1 9.1
1, and a holder 18 that holds 9.5 parts. Due to this two-dimensional arrangement, the end face of each optical fiber 19 is located on the (x, y) plane,
Each light emitting diode 20 is sequentially driven to turn on pulses in a time-division manner. Note that this light emitting diode 20 may be a semiconductor laser. Further, although the number of light emitting points of the light source 11 is set to 9×5, this is for the purpose of simplifying the drawing and explanation, and is not necessarily limited to this number.

The projection lens 12 is installed so that its optical axis is aligned with the center of the light emitting point g, which is the center of the 45 light emitting points arranged two-dimensionally, and each optical fiber 19
The light beam output from the end face of the device is focused and irradiated onto the object to be measured 13. Here, the optical axis of this light projecting lens 12 coincides with the Z axis, and will hereinafter be referred to as the distance detection axis. Then, the light emitting diode 20 of the light source 11 changes from g to g.
An irradiation pattern is drawn on the object to be measured 13 by sequentially turning on pulses from 1.1 to 9.5 in time division. The illustrated state shows a state in which the light emitting point g is turned on.

5.31 Note that in the irradiation pattern, only one point is irradiated instantaneously, and the other points are only visible as afterimages.

The reflected light from the object to be measured 13 is transmitted through a pair of light receiving lenses 14 and 1 arranged symmetrically around the distance detection axis (Z axis).
The light is received by 5. The received light flux is condensed and irradiated onto a pair of position detection light receiving elements 16 and 17. The pair of position detection light receiving elements 16 and 17 are arranged symmetrically about the distance detection axis, and generate output signals corresponding to the focusing positions of the light beams focused on each light receiving surface. .

The output signal is given to a calculation means to be described later, and
The distance (L) to each irradiation point above is calculated. In addition, the X
Each scanning angle (θ, θ) with respect to the axis and the Y axis is determined by the light source 11.
It can be known from the driving signal that the scan angle and the object to be measured 1
Three-dimensional position recognition becomes possible from the distance (L) up to 3.

FIG. 2 is a block diagram of a general semiconductor device detector used for the position detection light receiving elements 1, 6 and 17. As this semiconductor device detector, there is, for example, a one-dimensional semiconductor device detector manufactured by Hyomatsu Photonics Co., Ltd. with a model number 51662, and the case where this semiconductor device detector is used will be described below.

The semiconductor device detector 25 includes an n+ type half 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 half body 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.

If a predetermined voltage is applied to the common electrode 30 of this semiconductor device scraper 25 and a light spot is incident on the position SP, the pn junction below the position SP will have an electron-hole pair. occurs, and as a result, a photocurrent IO proportional to the incident energy of the light spot 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 R6, 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 Rx means photoelectric construction. is resistively divided at the light spot incident position SP.

That is, the current 1 to the electrode 31 and the current 8 to the electrode 32 are expressed by the following equations.

■ −■ −[Rx/Rc] Or '-t ・[(Ro-RX)/Ro]-(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.

I wA 11x/C O I -1・ [(C-x)/C co
-(3) O It is expressed as follows.

As can be seen from equation (3), the currents I and I are
B is taken out from the electrodes 31 and 32 and subjected to predetermined analog calculation processing by the calculation means described later.
2 to the light spot incident position SP can be determined.

FIGS. 3 and 4 are diagrams showing the principle of distance detection in an optical system using the three-dimensional position recognition device according to this embodiment. It is a diagram seen from above. In order to simplify the drawings and explanations, m-1 to 9(
Only the light-emitting points in columns) and n-1 (rows) are shown, and light-emitting points with n≧2 are omitted. Further, in the position detection light receiving elements 16 and 17, the electrodes 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. .

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

Figure 3 shows the light emitting point g - Ω of the light source 11.
9.1 This is a diagram showing the principle of distance detection 5.1 when the light emitting point g is lit in pulses.

Here, the distance from the distance detector to the n1 constant object 13 is L
1) Let LN be the distance when the object to be measured moves to the position indicated by the two-dot chain line 13'. Also, 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 B.
1 light receiving lens 14°15 to position detection light receiving element 16.
Let the interval up to 17 be f. In addition, the light receiving lens 14.1
The distances from the optical axis of X1 to each condensing position of the reflected light from the fixed object 13 on the light receiving surface of the position detection light receiving elements 16 and 17 are determined by the X1 object to be measured 13. The amount of movement of the focusing position when moving from N to N is ΔX and Δ, respectively.
Let it be x2. At this time, the following relational expression (4
) to (6) hold true.

x = f-B/Lo
=・(4)X+Δx −x+Δx −f−B/LN・
... (5) ΔXi - ΔX2 - f-B (1/L - 1/Lo) = (6) Therefore, from the photocurrent value I obtained from the position detection light receiving element 16.17, X, Δx1° By finding the value of B ΔX2, the object to be measured 13.1
It is possible to find the distances L and L to 3'. Each position detection light receiving element 16.1 determines the position where the light is focused on each light receiving surface when the object to be measured 13 is at a distance Lo.
If the object to be measured 13 is adjusted so as to coincide with the electrical center position of No. 7 (focusing position SP that becomes 1-IB). If it is located at a closer distance, the position detection light receiving element 16.
The light condensing position 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, 1111
1 constant 13 gari. If the light is located at a longer distance, the light focusing position moves to the inside of the electrical center position (toward the optical axis 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 (-).

Figure 4 shows the light emitting point g - Ω of the light source 11.
9.1 This is a diagram showing the principle of distance detection 1.1 when the light emitting point g is lit in pulses.

In this case, the light emitting point g is located 6g1 above the optical axis of the light projection lens 121.1 in the figure, so the irradiation position on the object to be measured 13 is below the optical axis of the light projection lens 12. become. Here, the subject n1 constant 13 is distance. If the light-receiving element 16.17 for position detection is located at
The positions are X and X away from the electrical center position of , respectively.

Further, when the object to be measured 13 moves to LN indicated by the two-dot chain line 13', the focal point of the spot light is shifted from the positions X, , X2 by ΔX and ΔX2, respectively.

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

x + x1 -f-(to B+, ill -L /f)/L.

−(f−B +ΔΩ・L)/L・
・・ (7)
... (8) IN N From these equations (7) and (8), the following equation (9) holds true.

Δx −(f−B+ΔN−I, )/LNt
IN-(f-B+6g・L)/L.

=, f−B(1/L −1/Lo)・(9) Next,
If the relational expression between the distance and the amount of displacement in the position detection light receiving element 17 is found in the same way, it will be as follows.

-x2 -f-(B-6g　-L　/f)/L.

-(f-B-ΔΩ ・L)/L...(10)x
−x2+Δx2 −f ・(B-6g φL / f ) / L
NN-(f-B-6g ・L)/L...(11)I
N N From these equations (10) and (11), the following equation (12) holds true.

Δx = (f-B-ΔΩ ・L)/LN2
1N-(fφB-Δg・L)/L.

10-f-B (1/L -1/Lo) ... (12) In equations (10) and (11), minus (
The reason for the presence of the symbol -) is that Xl is located outside the electrical center position of the position detection light receiving cable 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 Ω of the light source 11 has the same amount of displacement as when the pulse 5.1 was turned on.

Similarly, the other light emitting points Ω2,1~g and the light emitting points Ω~g of the light source 11 are pulse-lit 4.1
B, 1 9. Furthermore, when the relationship between the distance at the time and the amount of displacement of the spot light is determined, all of the relationships match Equation (6). That is, nine light emitting points (Ω ~ g
) Even when the light emitting point of the throat 1.1 9.1 is lit in pulses, the amount of displacement (ΔX, ΔX 2 )■ have the same value.

In other words, a pair of position detection light receiving elements 16 and 17
A photocurrent is generated by making a predetermined connection using a pair of one-dimensional semiconductor device detectors! , I
The signal calculation value indicating the distance to the object to be measured 13 is the same value as VB calculated as described below. This value indicates that regardless of which light emitting point among the nine light emitting points arranged on a straight line in the light source 11 is lit in pulses, the light irradiated from the light source 11 is transmitted to the distance detector (Z axis). ), the same numerical value will be obtained when irradiating a plane (X, Y plane) perpendicular to the plane (X, Y plane).

In addition, light emitting points g in m columns and n rows illuminate the object to be measured 13.
Even if the irradiation light beam is scanned in the Y-axis direction by sequentially lighting up the light-emitting points where n is other than 1 in pulses at the hour/minute 111+ time intervals, the light-emitting points on the light-receiving surfaces of the position detection light-receiving elements 16 and 17 will not be illuminated. It is clear that no change occurs in the displacement amounts Δx1 and Δx2 of the focused spot light in the X-axis direction. Therefore, the resulting photocurrent 1. The signal calculation value indicating the distance to the object to be measured 13 calculated from the IB is the same even if the light beam is scanned in the Y-axis direction when the (X, Y) plane is irradiated with the light beam. be able to.

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

Light source 11: 9 x 5 light emitting points p - Ω 1.1
9.5 is 9 x 5 light emitting diodes L E D 1,1~L
ED 9 , s are used, and these are pulse-lit in a time division +3 1.1 9.5 by a drive signal D −D from the LED drive circuit U . These pulse lighting operations are performed based on a lighting command from the timing controller U12.

The photocurrents I and In obtained in the position detection light receiving elements 16 and 17 are current-voltage conversion resistors r I, r
is converted into voltage signals V and vB by the capacitors C and C2, and the DC (direct current) component is removed by the capacitors C and C2, and only the AC (alternating current) component is sent to the amplifier circuit U1゜U2.
is sent to 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 U3 and the addition circuit U4, and vA-VB and V
A+VB calculations are respectively executed.

Each calculation signal is sent to sample-and-hold circuits U5 to U8, where it is sampled based on sampling signals S and S2 provided from timing controller U12, and the signal level is held.

That is, the potential immediately before each light emitting point is pulsed is sampled by the sampling signal S1 and recorded in the sample and hold circuits U and U7. On the other hand, the potential in the state where each light emitting point is lit in pulses is sampled by the sampling signal S2, and is recorded in the sample and hold circuits U and U8.

The subtraction circuit U9 subtracts the output value of the circuit U5 from the output value of the circuit U6, and the subtraction circuit U1o subtracts the output value of the circuit U7 from the output value of the circuit U8.

As a result, only the signal component caused by the pulsed lighting of the light source 11 is extracted. Then, in the arj-a arg divider UII, (VA-VB)/(V +V1
3) is executed.

This calculation result is output to the outside, and the distance detector
1 corresponds to the distance to the constant object 13, and becomes Z component data in three-dimensional position recognition. In addition, in synchronization with the output of the analog divider U1°1, the deflection angle of the light beam irradiated onto the object to be measured 13 is separated into an X-axis component (θX) and a Y-axis component (θ, ). Timing controller U12
The data is output 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 signal that scans the light emitting point in the X-axis direction of the drive signal that pulses the light source 11, and the component data is based on the signal that scans the light emitting point in the Y-axis direction of this drive signal. It is based on the signal that causes

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 object to be measured 13 can be easily determined from the output of the analog divider U11. 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)
XmL-tanθ, −(15) As described above, according to this embodiment, the 9×5 light emitting points arranged two-dimensionally are sequentially pulse-lit, so that the light beam emitted from the light source 11 is scanned two-dimensionally. Ru. For this reason, unlike conventional devices, the device (1) does not include any mechanically movable parts, and the scanning of the luminous flux is performed only by an electrical method.Therefore, the scanning of the luminous flux is performed with good responsiveness. The speed is increased and the measurement time required for one 3D position recognition is shortened.As a result, this device can also be applied to 3D position recognition devices that target dynamic n1 constant objects. become.

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 a case has been described in which the structure is configured using It has a similar effect. However, in this case, calculating the distance to the object to be measured becomes complicated and takes a little longer to calculate. Therefore, the apparatus having the configuration of the above embodiment is more suitable for dynamic APR objects that move at higher speeds.

〔Effect of the invention〕

As described above in detail, according to the present invention, the light beam emitted from the light source is two-dimensionally scanned by driving the two-dimensionally arranged light emitting points sequentially in a time-division manner with pulse lighting. For this reason, the beam scanning of the aP1 constant object is performed by electrical operation without mechanically moving parts, and the scanning performance of the beam irradiated from the light source is increased, reducing the time required for three-dimensional position recognition. Ru. As a result, there is an effect that an apparatus is provided that can target even dynamic objects 1Ip1, which have been difficult to recognize in three-dimensional position.

[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. Figure 4 is a diagram for explaining the principle of distance detection in 5.1 when the light emitting point g emits light in the device.
A diagram for explaining the principle of distance detection when the light emitting point g emits 1.1 in the device shown in the figure. FIG. 5 shows a signal processing circuit used in the device shown in FIG. The block diagram, FIG. 6, is a diagram showing a general distance detector. 11... Light source, 12... Emitter lens, 13... Δ-1 constant object, 14.15... Light receiving lens, 16.17
... Light receiving element for position detection, 18 ... Holder, one ... Optical fiber, 20 ... Light emitting diode. Agent Patent Attorney Yoshiki Hase - 11112 Chihiro Name of the Invention 4 Agent (Postal Code 1o1) U-, Y Pill 4° Floor 6, 2-7-9 Higashikanda, Chiyoda-ku, Tokyo Contents of Amendment (1) The scope of claims in the specification is as per the attached sheet. (2) Correct “luminous flux of light source 1” on page 2, line 10 of the specification to “light beam emitted from light source 1”. (3) Lines 4, 7, and 13 of page 4 of the specification. , 5 pages 2
Line 0, page 6 lines 14 and 18, page 7 lines 2, page 16 lines 3 and 4, page 18 line 9, page 19 line 2. Lines 11, 14 and 15 and page 20, line 13. The "luminous flux" in lines 16 and 17 is corrected to "light beam". (4) Correct "irradiation luminous flux" on page 15, line 18 of the specification to "light beam." Claim 1: A light source in which a plurality of light emitting points are two-dimensionally arranged and driven to turn on in pulses in a time-division manner, and a projection that condenses a light beam from each of the light emitting points and irradiates it onto an object to be measured. A light means, a light receiving means for condensing the reflected light from the object to be measured, a position detecting light receiving element for detecting the condensing position of the light beam focused by the light receiving means, and this position detecting light receiving element. a three-dimensional position recognition device, comprising: a calculation device that calculates a distance to an irradiation point of a light beam focused on the object to be measured based on an output signal of the object to be measured; 2. The light source consists of m x n light emitting elements, m x 0 optical fibers that propagate the light beam emitted from each light emitting element, and 2 x 0 optical fibers arranged in m columns and n rows on the output side end face of each optical fiber. 2. The three-dimensional position recognition device according to claim 1, further comprising a holder fixed to the three-dimensionally arranged light emitting points.

Claims (1)

[Scope of Claims] 1. A light source in which a plurality of light emitting points are two-dimensionally arranged and driven to turn on pulses in a time-division manner, and a light projection that condenses the luminous flux from each of the light emitting points and irradiates it onto an object to be measured. a light-receiving means for condensing reflected light from the object to be measured; a position-detecting light-receiving element for detecting the focal position of the light beam collected by the light-receiving means; and an output of the position-detecting light-receiving element. A three-dimensional position recognition device comprising: a calculation device that calculates a distance to an irradiation point of a light beam focused on the object to be measured based on a signal. 2. The light source includes m×n light emitting elements, m×n optical fibers that propagate the light flux emitted from each light emitting element,
2. The three-dimensional position recognition device according to claim 1, further comprising a holder for fixing the output side end face of each optical fiber to light emitting points arranged two-dimensionally in m columns and n rows.