JPH03175387A - Method and apparatus for measuring distance - Google Patents

Abstract

PURPOSE:To measure a distance over a wide range by mounting a rotary beam projection means rotating while projecting two laser beams holding a definite angle, a beam detection part detecting two laser beams and an operation part receiving a beam detection signal to calculate a distance. CONSTITUTION:One laser beam generated by a laser generator is emitted in a vertical upward direction from the lower part of a turntable 10 and passes through the hole 10a formed to the center of the turntable 10 to be incident to a prism 11. Next, the laser beam is changed by 90 deg. in its advance direction by the prism to advance in parallel to the upper surface of the turntable 10 and incident to the vicinity of one end parts of a plurality of prisms 12 mounted to the peripheral part of the turntable 10. Next, the laser beam is divided into two laser beams A, B and a laser stand 1 rotates while emits two laser beams A, B and the beams A, B rotated by 360 deg. within a horizontal plane while hold a definite angle theta0. A beam detection sensor 14 having width W1 is arranged to the beam detection part 2 of a target 20 to successively detect the beams A, B and a beam detection signal generation part generates a beam detection signal. This beam detection signal is transmitted to a time operation part to calculate beam detection time difference and this clocking data is transmitted to a distance operation part.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a distance measuring method and a device thereof, and in particular, to a distance measuring method and a device thereof, and particularly to a method for determining the distance from a reference point to a civil engineering vehicle, etc. using a laser beam. The present invention relates to a distance measuring method and a device suitable for this purpose.

[Conventional technology]

A conventional example is shown in FIG. 11 and FIG. 12.

In this conventional example, there are two laser lighthouses 100 that emit two laser beams of different heights that rotate in opposite directions, and a laser lighthouse 100 that is mounted on a target whose position is to be measured and receives the laser beams and sends a signal. A light receiving section 50 that emits light, a timing device (not shown) that measures the time interval at which light is received by the light receiving section 50 based on this signal, and two reference points using the light receiving time interval and the rotational speed of the laser beam. A,, B,
It is equipped with a computer (not shown) that calculates the angle from the two points and calculates the position based on the angle from these two points.

The laser lighthouse 100 includes a laser generator 511, a rotating table 522, a mirror 53 that rotates together with the rotating table, and a spectrometer 54.
．． It is composed of a fixed mirror 55. A through hole 52A is provided in the center of the rotary table 52, and a through hole 52A is provided in the center of the rotary table 52.
generates a laser beam vertically upward toward the through hole 52A from below in FIG. rotary table 5
A mirror 53 is placed above the through hole 52A of the second rotary table 52.
The rotary table 52 is fixed to the rotary table 52 and rotates together with the rotary table 52. A spectroscope 54 is arranged around the rotary table 52, and the laser beam A passes through the spectrometer 54 as it is, and the laser beam A that hits the spectroscope 54 changes direction and passes inside the spectrometer 54 upward. Then, it hits the reflective surface and changes its direction by 90 degrees, causing the rotary table 5 to change its direction by 90 degrees.
The light beam is split into a laser beam B directed toward the center of the laser beam B.

A fixed mirror 55 that does not rotate is fixed independently of the rotary table 52 above a mirror 53 that rotates together with the rotary table 52 at the center of the rotary table 52 . The laser beam B emitted from the spectroscope 54 hits the fixed mirror 55 and emits light that is symmetrical to the laser beam A with respect to the reference line. Therefore, the laser beam A rotates together with the rotary table 52, and the laser beam B is reflected by the fixed mirror 55 and rotates in the rotation plane one step higher than the laser beam A in the opposite direction to the laser beam A. (Situation shown in Figure 11).

Since the two laser lighthouses 100 are installed facing each other with their respective reference lines aligned, the measurement range is the range sandwiched between the two laser lighthouses 100 (in the state shown in Fig. 12). ).

In the light receiving unit 50A mounted on the measurement object 50, light receiving sensors are attached to the front and back sides of the separation plate, and each is set to receive only the laser beam from one of the laser lighthouses 100. Then, upon receiving the laser beam,
Emit light reception signal.

The object to be measured 50 further includes a timing device (not shown) that measures the signal interval based on the light reception signal generated by the light receiving section 50A, and the timing data obtained by this timing device is directly inputted to immediately calculate the coordinates. A computer (not shown) is equipped to calculate the .

[Problem to be solved by the invention] However, in the above conventional example, the laser lighthouse is
The disadvantage is that the equipment becomes large and expensive because it requires the use of a large number of bases. Also, using a reflector, 2
To rotate the book's laser beams in opposite directions,
There was an inconvenience in that it was possible to measure only the area between two laser lighthouses on one side of the mirror. [Object of the Invention] The purpose of the present invention is to improve the inconveniences seen in the conventional example and to provide an inexpensive method. An object of the present invention is to provide a distance measuring method and a distance measuring device that can measure targets over a wide range with the device.

[Means for Solving the Problems] In the present invention, one rotary light projection means rotates at a constant speed while projecting two laser beams that maintain a constant angle on the same rotational surface, and two One or more light receiving sections that sequentially receive the laser beams and generate light reception signals, and two laser beams that are the setting conditions and calculate time measurement data such as light reception time difference and light reception time from the light reception signals from the light reception sections. This method is equipped with a calculation unit that calculates the distance between the rotating light projecting means and the light receiving unit from the angle formed by the light receiving unit, the width of the light receiving unit, and time measurement data. This aims to achieve the above-mentioned purpose.

[For production]

The rotary light projecting means projects two laser beams at a constant angle within a rotating plane while rotating at a constant rotational speed. The light receiving section receives this light, generates a light reception signal for each laser beam, and transmits this signal to the calculation section.

The arithmetic unit calculates the difference in time at which the light receiving unit receives each laser beam from the transmitted light reception signal, and calculates the difference between this time difference and
The distance to the object to be measured is calculated based on the setting conditions such as the angle formed by the two laser beams.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

In the embodiment shown in FIG. 1, two laser beams A maintain a constant angle on the same rotational surface.

A laser lighthouse 1 as a rotary light projecting means that rotates at a constant speed while projecting light B, and two laser beams A and B.
one or more light receiving sections 2 that sequentially receive light and generate light receiving signals, and two laser beams A, which are a setting condition, as well as obtaining time measurement data such as a light receiving time difference and light receiving time from the light receiving signals from the light receiving sections 2. , H, the width of the light receiving section 2, etc., and a calculation section 3 that calculates the distance between the laser lighthouse 1 and the light receiving section 2 from time measurement data.

A laser lighthouse 1 disposed at one point (reference point) for measuring distance includes a laser generator 2 and a rotating table 10 (not shown).
．． Prism 11. It has a composite prism 12 and the like. A hole 10A is formed in the center of the rotary table 10,
A laser generator (not shown) is arranged below it. A prism 11 is disposed above the hole 10A on the rotary table 10, and a composite prism 12 is disposed near the periphery of the rotary table 10.

Here, as shown in FIG. 4(A), the laser beams A and B split into two by the composite prism 12 are
It is set so that it extends in the opposite direction to the light projection direction, and its intersection 13 is located at the position of the prism 11 located in the rotary table 10.

In addition, as shown in FIG. 2, the light receiving unit 2 disposed on the measuring object 20 for measuring distance receives the laser beams A and B projected from the laser lighthouse 1. The light receiving sensor 14 has a light receiving sensor 14, and a light receiving signal generating section 15 that generates a light receiving signal.

Here, the light receiving sensor 14 includes a photodiode.

Elements such as phototransistors are used.

The calculation section 3 includes a time difference calculation section 16 that receives the light reception signal transmitted from the light reception signal generation section 15 of the light reception section 2 and calculates the time width of the light reception signal and the light reception time difference;
6, and a distance calculation section 17 that calculates a distance using the angle θ0 formed by the two laser beams A and B, which is set in advance based on the calculation results sent from 6, and outputs a distance signal.

Next, the operation will be explained based on FIGS. 1 to 3.

One laser beam generated by a laser generator (not shown) is emitted vertically upward from the bottom of the rotary table 10, and a hole 1 formed in the center of the rotary table 10 is emitted.
The light passes through 0A and enters the prism 11. The incident laser beam is changed in direction by 90'' by this prism 11 and travels parallel to the table top surface.Then, the incident laser beam enters near one end of a composite prism 12 installed around the periphery of the rotary table IO. In this composite prism 12, one incident laser beam is divided into a laser beam A that passes through the composite prism 12 as it is, and a laser beam A that passes through the interior of the composite prism 12.
The direction is further changed near the other end of the composite prism 12, and the laser beam A and the angle θ are formed within the same horizontal plane. (Figure 4 (A)
The beam is split into two laser beams, with laser beam B being shifted by an amount (reference).

The laser lighthouse 1 rotates the rotary table 10 at a constant angular velocity by a motor (not shown), thereby splitting the laser beams A and B into two as described above.
It rotates while emitting light.

As a result, the two laser beams A and B form a constant angle θ. Rotate 360° in the horizontal plane.

The light receiving unit 2 of the target 20 whose distance is to be measured has a width W of 1
A number of light receiving sensors 14 are installed, and a laser beam A
, B one after another, and accordingly, the light receiving signal generating section 15
emits a light reception signal as shown in FIG. As shown in FIG. 2, these light reception signals are generated by the light reception signal generation section 1.
5 to the time difference calculation unit 16 of the calculation unit 3, and the time difference Δt1 during which the laser beam A is received and the time difference between the time when the laser beam A starts to be received and the time when the laser beam B starts to be received. A certain light reception time difference Δt2 is calculated, and these time measurement data are transmitted to the distance calculation unit 17 (see FIG. 3).

Subsequently, the distance calculation unit 17 calculates the light reception time Δ1. sent from the time difference calculation unit 16. and the light reception time difference Δt2 and the angle θ formed by the two laser beams A and B, which are the setting conditions.

and the size W of the light receiving sensor 14, the distance is calculated as follows.

Assuming that the distance between the two points you want to find is L, Figure 4 (A)
As shown in , θ is where L is the radius. The length of an arc with an angle of ° is L, = 2πL x θ. /360...It is expressed as (1).

On the other hand, the rotational angular velocity ω of the laser lighthouse 1. Since is constant, W+/Δj+=L+/Δt2 (2) holds true. Therefore, substituting equation (1) into equation (2) and summarizing, L=W, /ΔtI×Δtz/(2πθ./360)...
・The distance can be calculated as (3).

In the above calculation, strictly speaking, Wl is the length on the circular arc of the radius centered on the laser lighthouse 1, as shown in FIG. 4(A), but the central angle at this time is θ. Then, 2
πθ. Since it can be considered that /360<<1, the error can be ignored even if the straight line distance W+ is used.

Further, as shown in FIG. 4(B), when the light receiving section 2 is inclined by δ (r a d) with respect to the laser beam, it looks as if the light receiving section 2 has a width of Wb. Here, w-
>wb, Δtl becomes smaller, and the result is that L becomes larger according to equation (3). This becomes an error, but in the range where δ is small, w, = W, so,
The error is negligible. Here, in order to reduce δ, the light receiving section 2 may be made perpendicular to the laser lighthouse 1. In other words, control may be performed so that Δt1 becomes maximum at that position.

[Second Embodiment] Next, a second embodiment will be explained based on FIGS. 5 and 6.

In the second embodiment shown in FIG. 5, two light receiving sections are used instead of the one light receiving section 2 in the first embodiment described above.
That is, a first light receiving section 2A and a second light receiving section 2B are used. This case is considered to be a case in which the light receiving section 2- in the first embodiment described above is divided into two parts when the width of the light receiving section 2 is increased.

The received light signal in this case is shown in FIG. First light receiving section 2A
Let Δt be the light reception time difference between the light reception signal of the laser beam A received by the second light receiver 2B and the light reception signal of the laser beam A received by the second light receiver 2B. The light reception time difference with laser beam B is Δt2
shall be. Further, L is determined by the distance calculation section 17 performing the calculation of equation (3) in the first embodiment, assuming that the distance between the first light receiving section 2A and the second light receiving section 2B is Wl. In this case, since the value of Wl can be set to a large value, it is possible to obtain the distance with higher accuracy.

[Third Example] Next, a third example will be explained based on FIGS. 7 and 8.

In the third embodiment shown in FIG. 7, the light receiving section 2 is constructed by mounting a plurality of strip-shaped light receiving sensors 31 + SZ + . . . on the outer periphery of a cylindrical or regular polygonal member. ing.

As the laser beam from the laser lighthouse 1 rotates, the laser beam is applied to some of the plurality of light receiving sensors S,,S,,... The beam hits and generates a light reception signal, but the 8th
As shown in the figure, the light receiving sensor (in this case, SS) that has been receiving these signals for the longest time is considered to be directly facing the laser lighthouse 1. Therefore, in FIGS. 7 and 8, if the light reception signal of the light reception sensor S8 that has been receiving light for the longest time is selected and the light reception time Δt is used as Δt in the first embodiment, a more accurate distance can be obtained. Measurements can be taken.

With this configuration, a plurality of light receiving sensors 5ISZ+
Since it is considered that any one of the light receiving sensors S, 1 faces directly in the direction of the laser lighthouse 1, there is no need to be concerned about the orientation of the light receiving section 2. For this reason, the laser lighthouse 1 can be mounted on a moving object to be measured.
This is suitable for measuring the distance from to a moving object. Furthermore, it is even more effective when the moving body turns.

Furthermore, as shown in FIG. 7, for example, a light receiving sensor S
, S, . . . , S8 are arranged in a cylindrical shape, and one direction of them (for example, light receiving sensor S+Ss) is set to be the moving direction of the object to be measured.

Then, the adjacent light receiving sensor 31 + SZ + .
Let the angle formed by ... be Q (in the case of this example, Q=
360/8=45°). In this case, if the light receiving time of the light receiving signal from the light receiving sensor S is the longest, it can be seen that the light receiving sensor S is directly facing the laser lighthouse 1, so the direction of movement of the object and the direction of the laser lighthouse 1 are Toga,
As shown in FIG. 7, it becomes 450.

In this way, by associating the light receiving sensors s, 32, . . . with the moving direction of the object to be measured, the moving direction of the object to be measured can also be known.

[Fourth Example] Next, a fourth example will be explained based on FIGS. 9 and 10.

In the fourth embodiment shown in FIG. 9, the prism installed at the center of the rotary table 10 of the laser lighthouse 1 in the first embodiment is removed, and a composite prism 12 is vertically arranged in that position. , the laser beam coming from below the rotary table 10 is divided into two upper and lower laser beams A and B, and the rotation angle is θ. I try to keep it up.

Therefore, the laser beams A and B do not rotate on the same plane, but rotate on two different planes. Accordingly, two light receiving sections 2 are also disposed at the same position in a plane and at heights corresponding to the two laser beams A and B.

In this case as well, the distance between the laser lighthouse 1 and the light receiving section 2 can be determined in a plan view, as shown in FIG. 10, in exactly the same manner as in the first embodiment described above.

In this way, only one prism performs the same function, which further simplifies the layer device.

〔Effect of the invention〕

As explained above, the present invention includes one rotary light projector that rotates at a constant speed while projecting two laser beams that maintain a constant angle, and a rotary light projector that receives and receives two laser beams. It is equipped with a light-receiving section that generates a signal, and a calculation section that receives the light-receiving signal from the light-receiving section and calculates a distance. Therefore, as shown in the first embodiment, the distance can be measured by determining the time difference between when the light receiving section receives two laser beams emitted from one laser lighthouse, so the device is inexpensive. Accordingly, it is possible to provide an unprecedented and superior distance measuring method and distance measuring device that can easily measure distance over a wide range.

Moreover, in the invention as set forth in claim 4, since two light receiving sections are used, the light receiving time can be extended, which has the effect of enabling more accurate distance measurement.

In the invention set forth in claim 5, since there is no need to accurately orient the light receiving section mounted on the object to be measured in the direction of the laser lighthouse, not only can anyone easily set up the device, but also the device can be easily set up by anyone. This has the effect that the direction of movement can also be known.

In the invention of claim 6, since one laser beam can be divided into two laser beams using only one prism, there is an advantage that the -layer device is simple and inexpensive.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of the present invention, and FIG.
FIG. 3 is an explanatory diagram showing the light reception signal obtained in the embodiment shown in FIG. 1. FIG. ,
5 is a perspective view showing the second embodiment of the present invention, FIG. 6 is an explanatory drawing showing the received light signal in the embodiment shown in FIG. 5, and FIG. FIG. 8 is an explanatory diagram showing the light receiving section in the third embodiment of the invention. FIG. 8 is an explanatory diagram showing the light reception signals of each light receiving sensor in the third embodiment shown in FIG. 7. FIG. Perspective view representing an example, No. 10
The figure is a plan view of FIG. 9, FIG. 11 is an explanatory diagram showing a conventional example,
FIG. 12 is an explanatory diagram showing the measurement situation in the conventional example. 1... Laser lighthouse as a rotating light projecting means, 2.
... Light receiving section, 3 ... Calculation section.

Claims (6)

[Claims] (1) Two laser beams are emitted from one point while rotating at a constant speed on the same rotating surface, and the two laser beams are sequentially received at the other point. Generate a light reception signal, create data such as the light reception time difference and/or light reception time from this light reception signal, and set the setting conditions such as the angle formed by the two laser beams and the width of the light receiving part, and the light reception time difference and/or light reception time. A distance measuring method characterized in that the distance between the one and the other two points is calculated using time or the like. (2) one rotary light projector that rotates at a constant speed while projecting two laser beams that maintain a constant angle on the same rotating surface; and a light receiving section that generates a light receiving signal, and calculates time data such as a light receiving time difference and/or light receiving time based on the light receiving signal outputted from the light receiving section, and also calculates time data such as a light receiving time difference and/or a light receiving time, and also calculates time data such as a light receiving time difference and/or a light receiving time, and also calculates time data such as a light receiving time difference and/or a light receiving time, and also calculates time data such as a light receiving time difference and/or a light receiving time, and also calculates time data such as a light receiving time difference and/or a light receiving time, A distance measuring device comprising a calculation section that calculates the distance between the rotating light projecting means and the light receiving section based on the angle formed by the laser beam, the width of the light receiving section, etc. (3) The distance measuring device according to claim 2, wherein the light receiving section is constituted by a single light receiving section. (4) The distance measuring device according to claim 2, wherein the light receiving section is constituted by two light receiving sections. (5) The distance measuring device according to claim 2, wherein the light receiving section is constituted by a cylindrical sensor support member and a plurality of strip-shaped light receiving sensors attached to the outer periphery of the support member. (6) The two laser beams are rotated at a constant speed while maintaining a predetermined angle on two different planes, and the light receiving sections are two light receiving sections corresponding to the two planes. The distance measuring device according to claim 2.