JPH04198761A - Speed meter - Google Patents

Abstract

PURPOSE:To measure the speed quickly and easily by using two detectors with photo-interrupters projecting and receiving the light. CONSTITUTION:The photo-interrupter Ph12' of a detector 10' is rotated to the position where a light beam 14' is radiated to a regressive mirror 15. A photo-interrupter Ph12 is rotated to the position where the light beam 14 from the Ph12 is detected by the Ph12', and the relative angle theta1 is read. The relative angle theta2 between the direction that the beam 14' is radiated to the mirror 15 and the direction that the beam 14' is radiated to a mirror 16 is obtained. The angle beta between the perpendicular 17 drawn from the rotation center of the Ph12' to a straight line extended with the optical path of the beam 14 and the optical path of the beam 14' when the Ph12 is rotated until the beam 14' is radiated to the mirror 15 is obtained. The distance L between the detectors 10, 10' is obtained from the known distance (1) between the mirrors 15, 16 and the angles theta2, beta. The Ph12' is rotated by theta3 from the position where the beam 14' is radiated to the mirror 15 to make the beams 14, 14' parallel. The speed can be measured quickly and easily.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field)
Measure the time it takes for the light beams to sequentially cross the optical paths of the book, and use the time and the distance between the two light beams to determine the period during which the moving object moves across the optical paths of the two light beams. Concerning speedometers that measure average speed.

(Prior Art) One of the typical methods of measuring the speed of a moving object at a position distant from the moving object is to measure the speed of a moving object at a position distant from the moving object.
Light beams are emitted parallel to each other from each of the two light sources, and the time from the moment when a moving object crosses one of the optical paths of these two light beams to the moment when it crosses the other is measured, and this time and the above A method is known in which a predetermined distance is used to determine the section average speed when a moving object passes between the optical paths of the two light beams.

FIG. 7 is a schematic diagram of an example of a conventional speedometer that calculates the section average speed of a moving object based on the above method.

This speedometer consists of two light sources 1.2 that emit light beams, which are arranged at a predetermined distance L (m) from each other.
The optical paths of the light beams 3 and 4 emitted from the two light sources 1.2 are aligned so that they are parallel to each other and approximately perpendicular to the moving direction of the moving object (object to be measured) 5.
It is constructed by arranging light receivers 7 and 8 that receive the light beams 3 and 4 on opposite sides of the light sources 1 and 2 across the course of the light beams. In the speedometer configured in this way, the object to be measured 5
The time T (seconds) from the moment when the light beam crosses the optical path of the light beam 3 to the moment when the light beam crosses the optical path of the light beam 4 is measured with a timer (not shown), and this time T (seconds) and the above-mentioned predetermined distance L (
m), the section average velocity V of the object to be measured 5 is determined as: V=L/T (m/sec) (1).

(Problems to be Solved by the Invention) However, in the conventional speedometer shown in FIG. 7, alignment of the optical axes between the light source 1 and the light receiver 7 and alignment of the optical axes between the light source 2 and the light receiver 8 are complicated. There is a problem. Also, light sources 1 and 2
Since the receivers 7 and 7 are placed on opposite sides of the path of the object to be measured 5, the signal cable etc. will cross the path of the object to be measured 5, and the signal cables, etc. will cross the path of the object to be measured 5. Another problem is that it is difficult to arrange cables and the like. Furthermore, it is difficult to make the optical paths of the two light beams 3.4 parallel to each other, and it is a problem how to accurately measure the distance between the optical paths of the two light beams 5. However, in the case of a ship, for example, it is necessary to install either the light sources 1, 2 or the light receivers 7, 8 on the sea, which is impractical.

SUMMARY OF THE INVENTION In view of the various problems mentioned above, it is an object of the present invention to provide a speedometer that is easy to use and allows easy preparation before speed measurement.

(Means for Solving the Problems) A speedometer of the present invention for achieving the above object includes a first detector, a second detector, and a timer.

Here, the first detector includes a first light source that emits a first light beam forward and a first light source that receives a first reflected light from which the first light beam is reflected and returns backward. a first photointerrupter that is rotatable on a horizontal plane around a point on the optical path of the first light beam or an extension of the optical path or in the vicinity thereof; and a first angle meter for determining the relative angle of the rotation of the photointerrupter.

The second detector also includes a second light source that emits a second light beam forward and a second light source that receives a second reflected light that is reflected by the second light beam and returns backward. a second photointerrupter that is rotatable on a horizontal plane around a point on the optical path of the second light beam or an extension of the optical path or in the vicinity thereof; and a second angle meter for determining the relative angle of the rotation of the photointerrupter.

The timer also has a function of measuring the time between the moment when the first light receiver receives the first reflected light and the moment when the second light receiver receives the second reflected light. It is prepared.

Here, in the first speedometer of the present invention, the first photointerrupter is located on the central axis of the rotation of the first photointerrupter in addition to the first light source and the first light receiver. or its vicinity and a first predetermined distance in the horizontal direction from the central axis! the second light emitted toward the first photointerrupter from the second photointerrupter, which is located at a second predetermined distance from the first photointerrupter; The photointerrupter is characterized by comprising a first reflector and a second reflector, each of which reflects the beam toward the second photointerrupter.

Further, in the second speedometer of the present invention, in the first speedometer, the first photointerrupter is located on the center axis of the rotation of the first photointerrupter, instead of the first reflector. or the second light emitted toward the first photointerrupter from the second photointerrupter that is arranged at a second predetermined distance from the first photointerrupter in the vicinity thereof. The device is characterized in that it includes a first sensor that receives the beam.

Further, in the third speedometer of the present invention, in the first speedometer or the second speedometer, the first photointerrupter is replaced with the second reflector, and The second photointerrupter is disposed at a first predetermined distance l in the horizontal direction from the central axis of rotation, and the second photointerrupter is disposed a second predetermined distance apart from the first photointerrupter. The photointerrupter is characterized in that it includes a second sensor that receives the second light beam emitted toward the first photointerrupter.

Furthermore, in the fourth speedometer of the present invention, in any one of the first to third speedometers, the second photointerrupter is located at the center of rotation of the second photointerrupter. The first photointerrupter is injected toward the second photointerrupter from the first photointerrupter, which is disposed on or near the axis and at a second predetermined distance from the second photointerrupter. The photointerrupter is characterized by comprising a third reflector that reflects the light beam toward the first photointerrupter.

Further, in the fifth speedometer of the present invention, in the fourth speedometer, the second photointerrupter is arranged on the center axis of the rotation of the second photointerrupter, instead of the third reflector. or the first light emitted toward the second photointerrupter from the first photointerrupter disposed at a second predetermined distance from the second photointerrupter, or in the vicinity thereof; The device is characterized in that it includes a third sensor that receives the beam.

Furthermore, in the sixth speedometer of the present invention, in the first speedometer, the first photointerrupter includes both the first reflector and the second reflector; one photointerrupter includes the first reflector, the second photointerrupter is located a first predetermined distance l in the horizontal direction from the central axis of rotation of the second photointerrupter, The first light beam emitted from the first photointerrupter, which is disposed at a second predetermined distance from the second photointerrupter, toward the second photointerrupter, The photointerrupter is characterized in that it includes a fourth reflector that reflects the light toward the photointerrupter.

Further, in the seventh speedometer of the present invention, in the sixth speedometer, the first photointerrupter is arranged on the center axis of the rotation of the first photointerrupter, instead of the first reflector. or the second light emitted toward the first photointerrupter from the second photointerrupter that is arranged at a second predetermined distance from the first photointerrupter in the vicinity thereof. There is a patent that is characterized in that it includes a first sensor that receives a beam.

Further, in the speedometer according to a third aspect of the present invention, in the sixth speedometer or the seventh speedometer, the second photointerrupter is replaced with the fourth reflector; from the first photointerrupter, which is located a first predetermined distance apart from the second photointerrupter in the horizontal direction from the central axis of rotation of the first photointerrupter. The present invention is characterized in that it includes a fourth sensor that receives the first light beam emitted toward the second photointerrupter.

Here, in any one of the first to second speedometers configured as described above, the first and second photointerrupters repeat the first and second light beams in the vertical direction. Preferably, a light beam deflecting means for deflecting the light beam is provided.

In addition, the first to fourth reflectors are not limited to specific reflectors, but in order to increase the amount of reflected light as much as possible even when the light beam is irradiated somewhat obliquely. , such that the light beam that irradiates the reflector, such as a corner cube or a recursive mirror, passes through the optical path between the incident optical path of the light beam and returns to the light source from which the light beam was emitted. It is preferable to use a so-called return reflector that reflects the light beam.

Further, the first to fourth sensors may be ones that directly receive the light beam, or may be ones that guide the received light to the first light receiver or the second light receiver, such as optical fibers, etc. It may be.

Further, in the first to second speedometers, the first and second photointerrupters are configured to rotate around a point on the optical path of the light beam emitted from the photointerrupter or on an extension of the optical path. It is preferable that the first reflector, the first sensor, the third reflector, and the third sensor are provided on a central axis of rotation of the photointerrupter, In this case, the adjustment error and speed measurement error are minimized, but depending on how much adjustment error and speed measurement error are allowed, the center of rotation of the photointerrupter is determined by the light beam emitted from the photointerrupter. The first reflector and the first sensor may be deviated from a point on the road or an extension of the optical path.

The third reflector and the third sensor may be provided at a position offset from the central axis of rotation of the photointerrupter, and the "or its vicinity" in the first to third speedometers is It is interpreted in this way.

(Function) In the first speedometer of the present invention, both the first photointerrupter and the second photointerrupter are provided with an angle meter, and the first photointerrupter is provided with a first reflector. Therefore, the first light can be detected using this first reflector and the first light receiver built into the first photointerrupter or the second light receiver built into the second photointerrupter. The optical path of the beam and the optical path of the second light beam can be superimposed on each other, and then a goniometer can be used to make the optical paths of the first and second light beams parallel to each other. Furthermore, since the first photointerrupter is equipped with a second reflector in addition to the first reflector, the light beam emitted from the second photointerrupter illuminates one of these two reflectors. By measuring the relative angle between the irradiated state and the irradiated state, the difference between the first photointerrupter (first detector) and the second photointerrupter (second detector) is determined. Distance can be calculated. In this way, the distance can be easily determined, and the optical paths of the two light beams can be easily made parallel as described above.
Therefore, the speedometer can be easily adjusted and preparations for starting speed measurement can be made quickly.

Further, the second speedometer and the third speedometer of the present invention each include a first sensor and a second sensor that detect a second light beam instead of the first reflector and second reflector, respectively. These are the first sensors.

Using the second sensor, find the distance between the first photointerrupter (first detector) and the second photointerrupter (second detector) in the same manner as the first speedometer above. It is possible to easily make the optical paths of two light beams parallel! Therefore, the speedometer can be easily adjusted and preparations for starting speed measurement can be made quickly.

Further, in the fourth speedometer of the present invention, since the second photointerrupter in any of the first to third speedometers is also provided with a reflector (third reflector), the first photointerrupter is A first reflector provided on the second photointerrupter is irradiated with a second light beam emitted from a second photointerrupter, and a third reflector provided on the second photointerrupter is irradiated with a second light beam emitted from a second photointerrupter. By irradiating with the emitted first light beam, the first photointerrupter (first detector) and the second photointerrupter ( The distance between the two light beams (second detector) can be determined and the optical paths of the two light beams can be easily made parallel, so the speedometer can be easily adjusted in this case as well.
Preparations for starting speed measurement can be made quickly.

Further, the fifth speedometer of the present invention is equipped with a third sensor in place of the third reflector in the fourth speedometer, and can be easily adjusted in the same manner as the fourth speedometer. can be done.

Further, in the first speedometer, the first photointerrupter was equipped with both the first reflector and the second reflector, but in the sixth speedometer of the present invention, the first photointerrupter was equipped with both the first reflector and the second reflector. is equipped with a first reflector, and a second photointerrupter is equipped with a fourth reflector corresponding to the second reflector in the first speedometer, and using this first reflector, The optical paths of the two light beams are overlapped in the same way as the first speedometer, and from this state the first light beam emitted from the first photointerrupter illuminates the fourth reflector. By determining the relative angle between the first photointerrupter (first detector) and the second photointerrupter (second detector), the distance between the first photointerrupter (first detector) and second photointerrupter (second detector) can be determined. The light beams of can be made parallel to each other, so that this sixth speedometer can be easily adjusted.

Moreover, the seventh speedometer and the second speedometer of the present invention are those in which the first reflector and fourth reflector in the above-mentioned sixth speedometer are replaced with a first sensor and a fourth sensor, respectively. Therefore, adjustment is easily performed in the same manner as the sixth speedometer.

Here, in the above-mentioned first to second speedometers, if the first and second photointerrupters are provided with a light beam changing means for repeatedly changing the first and second light beams in the vertical direction, the reflector or The operation of irradiating the sensor with a light beam becomes easier, and even if the object to be measured swings vertically during speed measurement, the speed can be measured reliably.

(Example) Examples of the present invention will be described below.

FIGS. 1A and 1B are a plan view and a front view, respectively, showing the schematic configuration of a detector equipped with a photointerrupter that can be used as either a first photointerrupter or a second photointerrupter. This photointerrupter can be used as a photointerrupter for any of the first, fourth, and sixth speedometers referred to in the present invention, that is, speedometers that are configured only with a reflector without using a sensor that directly receives a light beam. be able to.

This detector 1O includes a photointerrupter I2 placed on a fixed base 1I, an angle meter 13 fixed to the fixed base 11, and a shaft 13a inserted into a hole lea provided in the fixed base 11. It consists of Photo interrupter 1
2 is attached to the shaft 13a of this angle meter 13,
It is configured to be able to rotate around this shaft 13a in the directions of arrows A and B shown in FIG. 1A, and to be able to read the relative angle of this rotation using the angle meter 13. The photointerrupter 12 also includes a light source (not shown) that emits a light beam 14 forward, and a light source (not shown) that reflects the light beam 14 and returns it through an optical path between the optical path of the light beam 14 and the optical path between the paths. A light receiver (not shown) is built in to receive the incoming light. Furthermore, this photointerrupter 12 has a built-in optical beam deflection means (not shown).
A light beam 14 repeatedly deflected at high speed in the vertical direction, that is, in the directions of arrows C and D shown in FIG. 1B, by this light beam deflecting means is emitted from the photointerrupter 12. As this light beam deflecting means, for example, a galvanometer mirror, a rotating polygon mirror, an acousto-optic light deflector, etc. are used.

Further, this photointerrupter 12 is equipped with a recursive mirror 15 on its rotation axis, and a distance l from the recursive mirror 15 behind the recurrent mirror 15.
Another recursive mirror 1B is provided at a position separated by the same amount. These recursive mirrors 15.16 direct the light beams irradiated toward the recursive mirrors 15.18 from the side side of the photointerrupter 12, that is, from the upper side or lower side in FIG. When the light is irradiated from the upper side of FIG. 1A, it is reflected toward the upper side, and when it is irradiated from the lower side of FIG. 1A, it is reflected toward the lower side.

Here, this recursive mirror 15. IG is the recursive mirror 15. Even if the angle of incidence of the light beam on the IG changes somewhat, the light beam is configured to be strongly reflected on the same optical path as the light beam.

FIG. 2 shows an example of an adjustment method before speed measurement when the speedometer using the two detectors shown in FIGS. 1A and 1B is used as the first speedometer according to the present invention. This is a diagram.

Each component constituting the first of the two detectors is shown with the same number as each component of the detector shown in FIG. Each of the components constituting the second detector is indicated by the same number as each component of the detector shown in FIG. 1 with a dash, and the explanation thereof will be omitted. Also, of the detectors shown in FIG. 1, the illustration of the fixed base 11 and the angle meter 13 is omitted here, and only the photointerrupter 12 is shown.

FIG. 2(a) shows a state in which two detectors 10, 10' are arranged substantially parallel to each other and separated by a distance. However, here, the arrangement was only done by visual measurement, and the distance has not yet been determined. Also, the two detectors 10 and 10' have the same number at the front and rear, and are arranged at a distance of X from each other. The light beam of the second detector 10'! The optical path 4' is the optical beam 1 of the first detector lO.
It is not parallel to the optical path No. 4, but is inclined by an angle α.

From this initial arrangement state, the light beam 14' emitted from the photointerrupter 12' of the second detector 10' is connected to the first detector 10' as shown in FIG. 2(b). The recursive mirror 15 of the detector IO is rotated to the irradiation position. The fact that the recursive mirror 15 is irradiated by the light beam 14' means that the recursive mirror 15
The reflected light of the light beam 14' is detected by being received by a light receiver (not shown) built in the photointerrupter 12' of the second detector 10'. Next, the photointerrupter 12 of the first detector 10 is
), the first light beam 14 emitted from the first photointerrupter 12 is rotated to a position where it is detected by a light receiver (not shown) built in the second photointerrupter 12'. and the relative angle θ1 between them is read by the angle meter 13 (see FIG. 1B). At this time, the optical paths of the two light beams 14 and 14' overlap with each other. Next, the photointerrupter 12 of the first detector 10 is returned to its original orientation, and the direction in which the light beam 14' emitted from the photointerrupter 12' of the second detector lO' irradiates the recursive mirror 15 is changed. The relative angle θ2 between the mirror 1G and the direction of irradiation is determined (FIG. 2(d)). Now these two regressive mirrors 15. Distance l between IG
is already known, and as shown in FIG. 2(d), the optical path of the light beam 14 is determined from the center of rotation of the photointerrupter 12' of the second detector 10' (the position of the recursive mirror 15'). Perpendicular line 17 drawn on the extended straight line and light beam 14
' Photo interrupter so that it illuminates the recursive mirror 15! The light beam when rotating 2'! When the angle formed with the optical path of 4' is β, the two detectors 10.10'
The distance between is L= l/ (tan (θ2+β) −tanβ)
...(2) becomes. However, here the angle is expressed in radians.

Here, β=π/2−θl (3), and θ
Since l is known, β is also known, so the distance can be found by performing calculations using the above equation (2).

Note that if the distance and distance l are set to satisfy L〉〉l, θ2 is sufficiently small and the initial arrangement (
At the stage shown in Fig. 2(a), these two detectors 10.10' are arranged so that the longitudinal deviation X (Fig. 2(a)) between the two detectors 10.10' is sufficiently small. In this case, the angle β also becomes sufficiently small, and therefore, in this case, equation (2) becomes L/θ2 (4). In other words, when these two assumptions, L>>l and β: small, are satisfied, the distance can be determined by a simpler calculation using equation (4) instead of equation (2).

Next, as shown in FIG. 2(e), the photointerrupter 1
2' is rotated by θ3=π-θl (5) from the position where the light beam 14' irradiates the recursive mirror 15, and as a result, the two light beams 14 and 14' The optical paths are parallel to each other.

Preparations for speed measurement are completed as described above, and thereafter, the time T (not shown) between the moment when the object to be measured, such as a car or ship, crosses the optical path of the light beam 14 and the moment when the object to be measured crosses the optical path of the light beam 14' is determined. Measured by a timer, the section average velocity V of the object to be measured while crossing the optical path of the two light beams 14.14' is determined by the above-mentioned formula (1), that is, V=L/T... - Obtained according to (1).

In this way, the distance between the two detectors 10.10' can be easily determined and the distance between the two light beams 10.
4.14' optical path can be easily made parallel,
Therefore, quick preparation for measurement becomes possible. In addition, since a reflective photointerrupter is used here, there is no need for signal cables to straddle the course of the object to be measured, making it suitable for measuring the speed of ships moving on the sea.

Here, the light beam reflected by the object to be measured 14°14
It is necessary to detect the reflected light of ', but in order to perform detection with a good SIN ratio, it is desirable to attach a reflector such as a recursive mirror to the object to be measured. In addition, by attaching a reflector such as a recursive mirror to the object to be measured (for example, a car), not only the object to be measured but also the same type of moving object (another car) other than the object to be measured can be Light beam 14.1
Even when moving across the optical path 4', it is possible to selectively detect only the desired object to be measured.

Further, in the above embodiment, as described above, the light beam 14.
14' is repeatedly deflected at high speed in the vertical direction (in the direction of arrows C and D in Figure 1B), so a considerable error is allowed in the mounting height of the reflector such as a recursive mirror attached to the object to be measured. Furthermore, when the object to be measured is a ship or the like, the speed can be reliably measured even if the ship or the like shakes up and down.

Furthermore, in the above embodiment, for the sake of detector compatibility, detectors having the same configuration were used as the two detectors 10 and 10', but as is clear from the explanation of the adjustment method above, the second detector The recursive mirror 15' and IG' are unnecessary, and therefore the speedometer using two detectors shown in FIGS. 1A and 1B is used here as the first speedometer according to the present invention. Become.

Here, the recursive mirror 15. of the first detector IO. l[i
are irradiated with light only from the second detector 1G' side, and therefore these recursive mirrors 15. As shown in FIG. 1A, the IG does not need to be a recursive mirror on both sides (upper and lower sides in FIG. 1A), and only one side on the second detector side needs to be a recursive mirror.

In this way, since the recurrent mirror only needs to be on one side, the recurrent mirror 15. The IG may be attached to the side surface of the housing of the photointerrupter 12 of the first detector IO on the second detector 1G' side. Recursive mirror 15. If the IB is attached to the side of the photointerrupter housing, these recursive mirrors is, ts will deviate from the extension of the optical path of the light beam 14, leading to distance measurement errors; If it is sufficiently large, the distance measurement error caused by the recursive mirrors 15, 18 being out of the extension of the optical path of the light beam 14 will be small. In this case, the mounting position of the recursive mirror 15 will be off the rotation axis of the photointerrupter 12, but this is because the error was allowed and it could be removed, and the present invention does not deal with such cases. is included in the present invention, expressed as "its vicinity".

Furthermore, the fact that the recursive mirror only needs to have regressive properties on one side is the same in all of the adjustment methods described below.Also, by allowing errors, the regressive mirror can be used on one side of the photointerrupter, etc. The same applies to the following.

In addition, instead of the above-mentioned regressive mirrors 15 and 16, one or both of them may be a sensor that detects the light beam 14', and the same applies hereinafter.

Further, in the above embodiment, the light beam 14.14' is vertically deflected, but it is not necessarily necessary in the present invention to deflect the light beam 14.14' vertically. If there is enough light, instead of deflecting the light beam 14, 14' vertically, for example, a cylindrical lens or the like may be used to emit a light beam having a vertically elongated cross-sectional shape. When the height of the light beam is constant, a light beam having a spot-like cross-sectional shape may be emitted without being vertically deflected.

FIG. 3 shows an example of an adjustment method before speed measurement when the speedometer using the two detectors shown in FIGS. 1A and 1B is used as the fourth speedometer according to the present invention. This is a diagram.

In this Figure 3, each component that corresponds to each component configuring the speedometer shown in Figure 2 is labeled with the same number as each component of the speedometer shown in Figure 2. , detailed explanation will be omitted.

FIG. 3(a) shows two detectors 1 as in FIG. 2(a).
0.10' are arranged substantially parallel to each other and separated by a distance from each other.

From this initial arrangement, the photointerrupter I2 of the first detector lO is rotated to a position where it illuminates the recursive mirror 15' of the second detector lO', as shown in FIG. 3(b). and the relative angle θl between them is read by the angle meter 13 (see FIG. 1B). Next, the photointerrupter 12 of the first detector 1O is returned to its original orientation, and this time the light beam 14' emitted from the photointerrupter 12' of the second detector 10' is directed toward the first detector 10. towards,
The angle θ2 between the direction in which the light beam 14' irradiates the recursive mirror 15 and the direction in which the recursive mirror 16 is irradiated is determined (FIG. 3(C)). Thereafter, the distance is determined and the two light beams 14, 14' are adjusted to be parallel to each other in the same manner as the adjustment method explained using FIG. 2.

In this way, even if this adjustment method is used, two detectors 10
．． You can easily find the distance between 10' and 2
The optical path of the book light beam 14, 14' can easily be made parallel, thus allowing rapid measurement preparation. Also, in this case, the regressive mirror 15. Since the IG 15' is used, only the recursive mirror 16' becomes unnecessary. By the way, these regressive mirrors! Of course, one or more of 5°te and is' may be replaced with a sensor that detects the light beam 14, 14'.

FIG. 4 shows an example of an adjustment method before speed measurement when the speedometer using the two detectors shown in FIGS. 1A and 1B is used as the sixth speedometer according to the present invention. This is a diagram.

In this FIG. 4, each component corresponding to each component constituting the speedometer shown in FIGS. 2 and 3 includes each component of the speedometer shown in FIGS. The same numbers are given and detailed explanations are omitted.

Figures 4(a) to 4(c) are respectively similar to Figure 2(a).
- This is the same figure as Fig. 2 (C), and Fig. 2 (a) - 2
Using the same adjustment method as explained with reference to FIG.
．． The optical paths 14' are adjusted so that they overlap with each other.

Next, as shown in FIG. 4(d), the photo interrupter 1
2' is rotated by θ3=π−θI −...−(5), and then rotated so that the light beam 14 emitted from the photointerrupter 12 illuminates the recursive mirror 111i'. The relative angle θ2 of rotation is determined. Once this relative angle θ2 is determined, the distance between the two photointerrupters 12, 12' is determined in the same way as explained using FIG. , the photointerrupter 12 is rotated by an angle θ1, which causes two light beams 14.1
The optical paths 4' are parallel to each other. Here, if this adjustment method is adopted, only the recurrent mirrors is, te' are required, and the recurrent mirrors 16, 15' are not required. Note that the light beam 14 is used instead of the regressive mirror 15, 1G'.
．． Of course, a sensor for detecting 14' may be provided.

FIG. 5 and FIG. 6 are diagrams showing other examples of the arrangement position of the recurrent mirror. In these figures 5 and 6, the second
Components that correspond to the components constituting the speedometer shown in Figures 2 to 4 are given the same numbers as the components of the speedometer shown in Figures 2 to 4. , detailed explanation will be omitted.

In FIG. 5, the photointerrupter I2 is equipped with two recursive mirrors 15, 16, and these two recursive mirrors 15. The IGs are arranged in a direction perpendicular to the optical path of the light beam 14 emitted from the photointerrupter 12. In this case, after overlapping the optical paths of the two light beams 14 and 14' with each other in the same manner as explained using FIGS. 2(a) to 2(C), the photointerrupter 12 is returned to its original state. Before orientation, the relative angle θ2 is determined as shown in FIG.

Further, in FIG. 6, the photointerrupter 12 is equipped with a recursive mirror 15 on its rotating wheel, and the photointerrupter 12' is equipped with a recursive mirror IG' at one end thereof. In this case, FIGS. 4(a) to 4(c)
), two light beams 1
After the optical paths 4.14' are superimposed on each other and before rotating the photointerrupter 12', the relative angle θ2 is determined as shown in FIG.

In this way, one of the two recursive mirrors (or sensors) is placed on or near the rotating wheel of the photo-interrupter 12, and the other is placed on the photo-interrupter 12 or the photo-interrupter! If the two photo interrupters 12.
The distance between 12' and 2
The optical paths of the book light beams 14, 14' can be adjusted to be parallel to each other.

(Effects of the Invention) As explained above in detail, the speedometer of the present invention has a speedometer in which the first detector detects the relative angle of rotation of the first photointerrupter and the first photointerrupter. an angle meter, the second detector includes a second photointerrupter and a second angle meter for determining the relative angle of rotation of the second photointerrupter; A reflector or sensor is provided on or near the rotating wheel of the first photointerrupter or the second photointerrupter, and at least one other reflector or other sensor is provided at a location away from the rotating wheel of the first photointerrupter or the second photointerrupter. The distance between the first and second detectors can be easily determined, and the optical paths of the two light beams emitted from the first and second detectors can be easily adjusted so that they are parallel to each other. Therefore, quick measurement preparation is possible, and a speedometer that is easy to use is realized.

Further, in the present invention, since a reflective photointerrupter is used, the signal cable etc. do not cross the path of the object to be measured, and from this point of view as well, the speedometer becomes easy to use. In addition, since a reflective photointerrupter is used, by attaching a reflector such as a recursive mirror to the object to be measured, it is possible to selectively detect only the desired object from among a large number of moving objects. can.

Furthermore, if the light beams emitted from the first and second photointerrupters are repeatedly deflected in the vertical direction,
For example, even if the object to be measured swings up and down, such as a ship on the sea, speed can be measured reliably, and reflected light can be detected with a better SIN ratio than when the light beam is spread vertically. becomes possible.

[Brief explanation of the drawing]

1A and 1B are plan views, respectively, showing the schematic configuration of a detector equipped with a photointerrupter that can be applied to either the first photointerrupter or the second photointerrupter according to the present invention. and a front view, Figures 2 to 6 are diagrams showing each adjustment method before speed measurement of the speedometer using two detectors shown in Figure 1, Figure 7 is a diagram showing a moving object 1 is a schematic configuration diagram of an example of a conventional speedometer that calculates the average speed in a section. 1.2...Light source 3,4...Light beam 5...Moving object (object to be measured) 6
...Path of the object to be measured 7.8 ...Receiver 10.10'...
...Detector 11...Fixed base 12.12'...Photo interrupter 13
...Angle meter 14.14'...Light beam 15.15', 16.18'...River recursion mirror Fig. 3 (a) Fig. 2 (b) (C ) to (a) (d) evil 4 figure (b) (C)

Claims (9)

[Claims] (1) A first light source that emits a first light beam forward, and a first light receiver that receives a first reflected light that is reflected by the first light beam and returns to the rear. , a first photointerrupter that is rotatable on a horizontal plane around a point on or near a point on the optical path of the first light beam or an extension of the optical path; and the rotation of the first photointerrupter. a first detector having a first goniometer for determining the relative angle of motion; a second light source that emits a second light beam forward; and a second light beam that is reflected backward; a second light receiver that receives a second reflected light that returns to the second light beam; a second detector having a second photointerrupter provided and a second angle meter for determining the relative angle of the rotation of the second photointerrupter; a timer that measures the time between the moment when the first reflected light is received and the moment when the second light receiver receives the second reflected light; on or near the central axis of rotation of the photointerrupter and at a position horizontally a first predetermined distance away from the central axis;
The second light beam emitted toward the first photointerrupter from the second photointerrupter, which is located a second predetermined distance away from the first photointerrupter, is directed to the second photointerrupter. A speedometer comprising a first reflector and a second reflector, each of which reflects toward a photointerrupter. (2) In place of the first reflector, the first photointerrupter is arranged on or near the central axis of rotation of the first photointerrupter, and a second A claim characterized by comprising a first sensor that receives the second light beam emitted toward the first photointerrupter from the second photointerrupter located a predetermined distance apart. The speedometer according to item 1. (3) The first photointerrupter, instead of the second reflector, is placed at a position horizontally a first predetermined distance away from the central axis of rotation of the first photointerrupter. a second sensor that receives the second light beam emitted toward the first photointerrupter from the second photointerrupter, which is disposed a second predetermined distance apart from the photointerrupter; The speedometer according to claim 1 or 2, further comprising: a speedometer. (4) The second photo-interrupter is arranged on or near the central axis of rotation of the second photo-interrupter and at a second predetermined distance from the second photo-interrupter. It is characterized by comprising a third reflector that reflects the first light beam emitted from the first photointerrupter toward the second photointerrupter toward the first photointerrupter. A speedometer according to any one of claims 1 to 3. (5) Instead of the third reflector, the second photointerrupter is arranged on or near the central axis of the rotation of the second photointerrupter, and has a second A claim further comprising: a third sensor configured to receive the first light beam emitted from the first photointerrupter to the second photointerrupter, which is located a predetermined distance away from the first photointerrupter. The speedometer according to item 4. (6) Instead of the first photointerrupter including both the first reflector and the second reflector,
The first photo-interrupter includes the first reflector, and the second photo-interrupter is located at a first predetermined distance in a horizontal direction from the central axis of rotation of the second photo-interrupter. , the first light beam emitted from the first photointerrupter, which is disposed at a second predetermined distance from the second photointerrupter, toward the second photointerrupter; The speedometer according to claim 1, further comprising a fourth reflector that reflects the light toward the photointerrupter. (7) Instead of the first reflector, the first photointerrupter is arranged on or near the central axis of rotation of the first photointerrupter, and a second A claim characterized by comprising a first sensor that receives the second light beam emitted toward the first photointerrupter from the second photointerrupter located a predetermined distance apart. The speedometer according to item 6. (8) In place of the fourth reflector, the second photointerrupter is located at a position horizontally a first predetermined distance away from the central axis of rotation of the second photointerrupter. and a fourth sensor that receives the first light beam emitted from the first photointerrupter toward the second photointerrupter, which is disposed at a second predetermined distance from each other. The speedometer according to claim 6 or 7, further comprising: a speedometer. (9) The first and second photointerrupters include light beam deflection means for repeatedly deflecting the first and second light beams in the vertical direction. The speedometer according to any one of the items.