JP2005222413A - Vehicle height measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To conduct high-speed vehicle height measurement. <P>SOLUTION: A vehicle measuring instrument is configured to repeat measurement having wide measurement intervals and the measurement having narrow measurement intervals. Thus, the location of the vehicle height is roughly specified by conducting the measurement having the wide measurement intervals. Consequently, the measurement is conducted for only the specified height in the following measurement having the narrow measurement intervals. In addition, the vehicle height is measured at the narrow measurement intervals without light-emitting light emitting devices T for all the heights. Furthermore, it is not required to light the light emitting devices T for all the heights. Consequently, time required for light-emitting the light emitting devices T is reduced and the high-speed measurement is allowed to suppress power consumed due to light emission of the light emitting devices T. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle height measuring device, and more particularly to a vehicle height measuring device that measures a vehicle height using light emitters and light receivers arranged in a height direction.

Conventionally, this type of vehicle height measuring device has light emitters arranged vertically on one side across a vehicle passage, and light receivers arranged vertically on the other side. What emits light in a divided manner is known (for example, see Patent Document 1 and FIG. 3).
According to this configuration, light is emitted from a plurality of light emitters in a time-division manner at a predetermined period, so that detection light emitted from the plurality of light emitters is not incident on the same light receiver at the same time. Therefore, even if the detection light is diffused, it is possible to perform accurate vehicle height measurement without erroneous detection.
JP 2002-56492 A

However, since light is emitted from a plurality of light emitters in a time-division manner at a predetermined period, a time obtained by multiplying the light emission period by the number of light emitters is required to emit light from all the light emitters. Therefore, it takes a long time to detect an obstruction at all measurement heights. Therefore, when trying to measure the vehicle height at a high density in the vehicle length direction, there is a problem that the traveling vehicle must be decelerated or the vehicle must be guided to a roadway or the like different from the traveling lane.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a vehicle height measuring device capable of high-speed measurement.

In order to achieve the above object, according to the first aspect of the present invention, there is provided a pair of measurement poles facing each other with the vehicle sandwiched in the vehicle width direction, and a light emitting portion and a light receiving portion facing each other between the pair of measurement poles. A light emitter and a light receiver disposed at each of a plurality of measurement heights in the measurement pole, a light emission control means for controlling light emission of detection light in the light emitter, and a light receiving state in each light receiver. Vehicle height measuring means for specifying that the vehicle height is a height between the light receiving device at the highest position where the detection light is not received and the light receiving device at the lowest position where the detection light is received. In the vehicle height measuring device provided,
It is configured to repeatedly perform a wide measurement and a narrow measurement.

  In the invention of claim 1 configured as described above, at least a pair of measurement poles are installed with the vehicle sandwiched in the vehicle width direction. The light emitter and the light receiver are arranged at a plurality of heights in the measurement pole so that the light emitting portion of the light emitter and the light receiving portion of the light receiver face each other between the pair of measurement poles. The light emission control means controls the light emission in the light emitters, the vehicle height measuring means obtains the light reception state in each of the light receivers, and the light receiver at the highest position where the detection light is not received and the detection light are received. Identify the receiver at the lowest position. And it specifies that vehicle height is the height between these.

  First, it is possible to roughly specify where the vehicle height is by performing measurement with a wide measurement interval. Therefore, in the next measurement with a narrow interval, it is possible to perform a measurement with a narrow interval only for the specified height. Accordingly, a plurality of light emitters and light receivers are alternately controlled, so that high-speed measurement is possible.

  According to a second aspect of the present invention, the two light emitters closest to each other in the height direction among the plurality of light emitters that the light emission control unit emits simultaneously are arranged on the different measurement poles. It is as.

  In the invention of claim 2 configured as described above, the pair of measurement poles are installed with the vehicle sandwiched in the vehicle width direction. The light emitter and the light receiver are arranged at a plurality of heights in the measurement pole so that the light emitting portion of the light emitter and the light receiving portion of the light receiver face each other between the pair of measurement poles. The light emission control means controls the light emission in the light emitters, the vehicle height measuring means obtains the light reception state in each of the light receivers, and the light receiver at the highest position where the detection light is not received and the detection light are received. Identify the receiver at the lowest position. And it specifies that vehicle height is the height between these.

  Since the light emission control means causes the plurality of light emitters to emit light at the same time, it is possible to detect the vehicle at a plurality of measurement heights at the same time. Therefore, it is possible to perform measurement at a higher speed than when the vehicle height is measured by sequentially emitting the light emitters at each measurement height. Furthermore, by arranging the two light emitters closest to the height direction among the plurality of light emitters that the light emission control means emits at the same time on the measurement poles different from each other, light is emitted simultaneously at the closest height. The two traveling directions of the detection light can be opposite to each other. Therefore, even if the detection light diffuses before reaching the opposing measurement pole, it is not detected by being confused with another detection light emitted at the closest height. That is, it is possible to perform accurate vehicle height measurement while preventing erroneous detection while simultaneously increasing the speed of measurement by simultaneously emitting light from the plurality of light emitters.

  According to a third aspect of the present invention, in the first measurement timing, the light emission control means includes a plurality of the light emission thinned out in the height direction so that one or more light emitters that do not emit light exist between them. And the second measurement timing is positioned between the highest light receiver where the detection light is not received at the first measurement timing and the lowest light receiver where the detection light is received. The light emitter is configured to emit light.

  In the invention of claim 3 configured as described above, the light emission control means emits light at the first measurement timing and the second measurement timing, respectively. At the first measurement timing, the plurality of light emitters thinned out in the height direction so that one or more light emitters that do not emit light exist in between. That is, at the first measurement timing, the vehicle height can be roughly specified by thinning the light emitter in the height direction for measurement. Then, at least one of the light emitters present between the highest position where the detection light is not received at the first measurement timing and the lowest position where the detection light is received is the second. The light is emitted at the measurement timing.

  That is, at the second measurement timing, the vehicle height can be measured in more detail at the height roughly specified at the first measurement timing. It is not necessary to cause the light emitter that does not exist between the highest light receiver where the detection light is not received at the first measurement timing and the lowest light receiver that receives the detection light to emit light. Accordingly, the number of light emitters that emit light can be reduced compared with the case where the vehicle height is measured by sequentially emitting light from the light emitters at all measurement heights, thereby enabling high-speed measurement. In addition, power consumption can be suppressed. The vehicle height measuring means includes the light receiving device at the highest position where the detection light is not received through the first measurement timing and the second measurement timing, and the light receiving device at the lowest position where the detection light is received. It can be specified that the height between them is the vehicle height.

  Further, in the invention according to claim 4, the light emission control means receives the detection light at the second measurement timing and the light receiving device at the highest position where the detection light is not received at the first measurement timing. The light emitting device that emits light at the second measurement timing when the light emitting device at a predetermined position with respect to the light receiving device at the lowest position emits light and no detection light is detected at the second measurement timing. The light emitting device at a position higher than the light receiving device and at a position lower than the light receiving device at the lowest position where the detection light was received at the first measurement timing is caused to emit light at the third measurement timing, and the second measurement is performed. If the detection light is detected at the timing, the detection light is not received at the first measurement timing at a position lower than the light emitter that is emitted at the second measurement timing. The light emitting device of the position higher than the light receiver of the highest position Tsu is a structure in which light is emitted in a third measurement timing.

  In the invention of claim 4 configured as described above, at the second measurement timing, the receiver at the highest position where the detection light is not received at the first measurement timing, and the receiver at the lowest position where the detection light is received. The light emitter located at a predetermined position with the light receiver is caused to emit light. If the detection light is received at the second measurement timing, the vehicle height is the highest position at which the detection light is not received at the first measurement timing, and the lowest position at which the detection light is received. It can be specified that the vehicle height is lower than the position of the light emitting device that emits light at the second measurement timing. On the other hand, if the detection light is not received at the second measurement timing, the vehicle height is the highest position at which the detection light is not received at the first measurement timing, and the light reception at the lowest position where the detection light is received. It can be specified that the height of the vehicle is higher than the position of the light emitter that emits light at the second measurement timing.

  And when it is specified at the second measurement timing that the vehicle height is that of the former, the light emitter of the height in the specified range at the third measurement timing is caused to emit light, and Measure the vehicle height in detail. Similarly, when it is specified at the second measurement timing that the vehicle height is the latter, the above-mentioned light emitter having a height in the specified range at the third measurement timing is caused to emit light, The vehicle height can be measured in more detail.

  Thus, in the second and third measurement timings, the light receiving device at the highest position where the detection light is not received at the first measurement timing and the light receiving device at the lowest position where the detection light is received exist. Since the vehicle height can be measured without causing all of the light emitters to emit light, the vehicle height can be measured faster than when the light emitters are sequentially emitted to measure the vehicle height. Moreover, since the said light-emitting device made to light-emit can be further limited, power consumption can be suppressed more.

  Further, the invention according to claim 5 is the provisional vehicle height measuring means for temporarily measuring the vehicle height upstream of the measurement pole in the traveling direction of the vehicle, and the vehicle height detected by the temporary vehicle height measuring means. The light emission control means acquires the vehicle height stored in the vehicle height storage means, and uses only the light emitter having a height corresponding to the vehicle height at the measurement pole. The vehicle height measuring means is configured to identify the vehicle height from the light receiving state of the light receiver facing the light emitter.

  In the invention of claim 5 configured as described above, the temporary vehicle height measuring means temporarily measures the vehicle height upstream of the measurement pole in the traveling direction of the vehicle. The measured vehicle height is stored by the vehicle height storage means. The light emission control means acquires the vehicle height from the vehicle height storage means, and causes only the light emitter having a height corresponding to the vehicle height to emit light at the measurement pole. And the said vehicle height measurement means pinpoints a vehicle height from the light-receiving state of the said light receiver facing the said light-emitted light emitter. That is, by preliminarily measuring the vehicle height in advance, only the necessary light emitters can be caused to emit light at the measurement pole.

  The provisional vehicle height measuring means may be a simple one as long as the vehicle height can be roughly measured. Of course, the vehicle height may be specified using a plurality of light receivers and light emitters arranged in the height direction across the vehicle width. In this case, the vehicle height can be roughly measured in advance by making the interval between the light receiver and the light emitter of the temporary vehicle height measuring means adjacent to each other in the height direction wider than that of the measurement pole.

  Furthermore, the invention according to claim 6 includes vehicle speed detection means for detecting the vehicle speed of the vehicle upstream of the measurement pole in the traveling direction of the vehicle, and vehicle speed storage means for storing the detected vehicle speed of the vehicle. The light emission control means acquires the vehicle speed, predicts the time when the vehicle reaches the measurement pole from the vehicle speed, and starts the light emission of the light emitter of the measurement pole at the predicted time.

  In the invention of claim 6 configured as described above, the vehicle speed detecting means measures the vehicle speed of the vehicle upstream of the measurement pole in the traveling direction of the vehicle. The measured vehicle speed is stored in the vehicle speed storage means. The light emission control means obtains the vehicle speed from the vehicle speed storage means and predicts the time for the vehicle to reach the measurement pole from the vehicle speed. And the said light emission control means starts light emission of the said light emitter of the measurement pole at the estimated time. That is, by predicting the time to reach the measurement pole, the light emitter can emit light only for a necessary time.

The invention according to claim 7 comprises an output means for outputting the vehicle height specified by the vehicle height measuring means.
In the invention of claim 7 configured as described above, the output means outputs the vehicle height specified by the vehicle height measuring means. That is, the measurement result can be output.

As described above, according to the first and third to fifth aspects of the present invention, it is possible to provide a vehicle height measuring device capable of high-speed measurement by simultaneously controlling a plurality of light emitters.
According to the second aspect of the present invention, it is possible to provide a vehicle height measuring device capable of performing high-speed measurement by preventing erroneous detection from occurring even when many light emitters are caused to emit light simultaneously.
According to the invention of claim 6, since it is possible to emit light only for a necessary period, power consumption can be suppressed.
According to invention of Claim 7, a measurement result can be output.

Here, embodiments of the present invention will be described in the following order.
(1) First embodiment:
(2) Second embodiment:
(3) Third embodiment:
(4) Fourth embodiment (5) Summary:

(1) First embodiment:
FIG. 1 shows the appearance of the vehicle height measuring device according to the first embodiment of the present invention as seen from an oblique direction. In the figure, a pair of measurement poles A and B are erected on the outer side in the width direction of the vehicle passage 50. The measurement target vehicle 60 (hereinafter simply referred to as the vehicle 60) can pass between the measurement poles A and B, and the measurement poles A and B are formed sufficiently higher than the vehicle 60. Further, the measurement pole B is provided with a display 26 for displaying the measurement result and a printer 28 for printing the measurement result.

  FIG. 2 shows the measurement poles A and B as viewed from the inside (vehicle passage 50). In the figure, the measuring pole B is provided with light emitters Ta0, Tc1, Tb1, Tc2,. The light receiving devices Sa0, Sc1, Sb1, Sc2... Indicated by .largecircle. On the measurement pole A so as to face the light emitters Ta0, Tc1, Tb1, Tc2. Are arranged with the light receiving part facing inward. Further, light emitters Tc1, Tc2, Ta2, Tc3,... Are arranged on the measurement pole A, and light receivers Sc1, Sc2, Sa2, Sc3,. It is arranged.

  Comparing the heights of the light emitter T and the light receiver S disposed on each of the measurement poles A and B, the light emitter T and the light receiver S facing the light emitter T are arranged so as to have the same height. . Thereby, the detection light emitted substantially horizontally from the light emitter T can be received by the opposing light receiver S. Further, in both of the measurement poles A and B, the intervals between the light emitters T adjacent to each other in the height direction, the light receivers S, and the distance between the light emitter T and the light receiver S are all 2 cm. Therefore, the minimum interval in the height direction of the detection light emitted from each light emitter T is also 2 cm.

  The light emitter T and the light receiver S are classified into blocks represented by X1, X2, X3... X (n). Note that n is a natural number and means a block number. Each block X (n) is composed of three sets of opposing light emitters T and light receivers S that are continuous in the height direction. Therefore, in each block X (n), detection light can be received and emitted at the highest position, the middle position, and the lowest position. In each block X (n), the highest position light emitter T is disposed on the measurement pole B, and the highest position light receiver S is disposed on the measurement pole A, thereby detecting light emitted at the highest position. Advances from the measurement pole B to the measurement pole A.

  Further, by arranging the light emitter T at the middle position on the measurement pole A and the light receiver S at the middle position on the measurement pole B, the detection light emitted from the middle position is emitted from the measurement pole A. It proceeds to the measurement pole B. That is, the light emitter T and the light receiver S are arranged so that the detection light emitted at the highest position and the middle position in each block X (n) is in opposite directions. It should be noted that the light emitter T and the light receiver S arranged at the highest position and the middle position are indicated by adding c as a subscript and the number n of each block X (n).

  On the other hand, at the lowest position in each block X (n), the light emitters Ta (n), Tb (n) and the light receiving elements indicated by adding a or b as a subscript and the number (n) of each block. Containers Sa (n) and Sb (n) are provided. In each of the blocks X (n) in which the block number n is an odd number (n = 2m-1 is satisfied, where m is a natural number), the light emitter Tb (n) with the subscript b added to the lowest position. And the light receiver Sb (n) are arranged to face each other. Further, in the block X (n) whose block number n is an odd number and satisfies the number n = 4m−3, the light emitter Tb (n) is disposed on the measurement pole B, and the light receiver facing it. Sb (n) is disposed on the measurement pole A. In the block X (n) with the block number n being an odd number and satisfying n = 4m−1, the light emitter Tb (n) is disposed on the measurement pole A and the light receiver Sb ( n) is arranged on the measuring pole B.

  That is, the traveling directions of the detection lights transmitted and received at the light emitter Tb (n) and the light receiver Sb (n) to which the subscript b is added, which are closest to the height direction, are opposite to each other. Yes. For example, in the light emitter Tb1 and the light receiver Sb1, the detection light travels from the measurement pole B toward the measurement pole A, whereas in the light emitter Tb3 and the light receiver Sb3 that are closest thereto, the detection light is transmitted to the measurement pole A. To the measuring pole B.

  In each of the blocks X (n) where the block number n is an even number (satisfying n = 2m), the light emitter Ta (n) and the light receiver Sa (n) with the subscript a attached to the lowest position. ) Are arranged opposite to each other. Further, in the block X (n) with the block number n being an even number and satisfying n = 4m−2, the light emitter Ta (n) is disposed on the measurement pole A, and the light receiver facing this. Sa (n) is disposed on the measurement pole B. In the block X (n) with the block number n being an even number and satisfying n = 4m, the light emitter Ta (n) is disposed on the measurement pole B, and the light receiver Sa (n) facing this. Is arranged on the measurement pole A.

  That is, the detection light transmitted and received in the light emitter Ta (n) and the light receiver Sa (n) to which the subscript a is added, and the traveling directions closest to the height direction are opposite to each other. Yes. For example, in the light emitter Ta2 and the light receiver Sa2, the detection light travels from the measurement pole A toward the measurement pole B, whereas in the light emitter Ta4 and the light receiver Sa4 closest thereto, the detection light is transmitted to the measurement pole B. To the measuring pole A. In the present embodiment, the detection light emitted from the light emitting unit is infrared light.

  FIG. 3 shows a hardware configuration of the vehicle height measuring device 10. In the figure, a control unit 20 for operating measurement poles A and B is provided. The bus 20a provided in the control unit 20 includes a CPU 21, a ROM 23, a RAM 22, a display 26 via an interface (I / F) 27, a printer 28 via an I / F 29, and an I / O 25. Measurement poles A and B are connected to each other. And CPU21 controls each part according to the program written in ROM23, using RAM22 as a work area. As described above, since each of the measurement poles A and B is provided with both the light emitter T and the light receiver S, the I / O 25 sends a signal for causing the light emitter T to emit light to each of the measurement poles A and B. In addition to outputting, an electrical signal indicating the light receiving state of the light receiver S is input from the measurement poles A and B. The display 26 displays the measured vehicle height, and the printer 28 prints and records the vehicle height on a recording medium such as paper.

  Although the display 26 and the printer 28 are connected to the bus 20a of the control unit 20, a wireless transmission / reception device or the like is interposed between the display unit 26 and the printer 28 so that the installation location of the display 26 and the printer 28 is flexible. Also good. In addition to outputting the measurement result to the output device such as the display 26 and the printer 28, a hard disk or the like may be provided when it is desired to store the measurement result as data.

  FIG. 4 shows a software configuration of the vehicle height measuring device 10. In the same figure, the control unit 20 is comprised from each module of the light emission control part M21, the vehicle height specific | specification part M22, the comparison part M24, and the output part M27. The light emission control unit M21 performs light emission control of the light emitter T provided in each of the measurement poles A and B, and the vehicle height specifying unit M22 indicates the light reception state of the light receiver S provided in each of the measurement poles A and B. The signal which shows is input, and the process which specifies a vehicle height as the measured value M from the signal is performed. The comparison unit M24 compares the measured value M specified by the vehicle height specifying unit M22 with the memory value J indicating the highest vehicle height stored in the vehicle height storage unit 22a assigned to the RAM 22, and the higher of these values A process for updating the RAM 22 is executed. The output unit M27 outputs the memory value J stored in the vehicle height storage unit 22a, which is finally assigned to the RAM 22 as the maximum vehicle height, to an output device such as the display 26 and the printer 28.

  FIG. 5 shows the flow of measurement processing in the control unit 20. In the figure, first, in step S110, a memory value J indicating the vehicle height stored in the vehicle height storage unit 22a assigned to the RAM 22 is initialized to zero. The vehicle height value stored in the vehicle height storage unit 22a is hereinafter simply referred to as a memory value J. In step S120, the light emitter Ta (n) and the light emitter Tb (n) are caused to emit light sequentially. That is, first, the light emission control unit M21 simultaneously emits all the light emitters Ta (n) to which the subscript a is added that are the light emitters T provided in the measurement poles A and B, respectively, for 4 ms (milliseconds). Later, all of the light emitters Tb (n) to which the subscript b is added, which are the light emitters T, emit light simultaneously. In other words, all the light emitting devices T in the lowest position in the block X (n) whose block number n is an even number are caused to emit light simultaneously, and 4 ms later, the lowest position in the block X (n) whose block number n is an odd number. All the light emitters T are caused to emit light simultaneously.

  As a result, since all of the light emitters Ta (n) and the light emitters Tb (n) emit light in step S120, the light emitters T at the lowest position in all the blocks X (n) are caused to emit light simultaneously. Can do. In other words, in step S120, light emission is performed by thinning the light emitter T in the height direction so that there is a light emitter Tc (X) that does not emit light by two between the light emitters Ta (n) and Tb (n) that emit light. can do. In the present embodiment, since the interval between the light receiver S and the light emitter T adjacent in the height direction is 2 cm, the detection light is emitted at intervals of 6 cm in the height direction. And while performing light emission in step S120, in step S130, the presence or absence of light reception is detected in each light receiver S, and vehicle height is specified. Specifically, the height of the light receiving device Sa (n), Sb (n) at which the vehicle height is received and the light receiving device Sa (n), Sb (n) at the highest position where light is not received. It can be seen that the height is between. Note that 4 ms is a time that must be secured as a minimum as a starting time for the light emitter T to stably emit light and a starting time for the light receiver T to stably receive light.

  FIG. 6 shows a state in which the light emitter T emits light as seen from the traveling direction of the vehicle. In the figure, in step S120, the light emitters Ta (n) emit light simultaneously as indicated by the solid line in the detection light. After 4 ms, the light emitters Tb (n) emit light at the same time as indicated by broken lines in the detection light. For example, if the head of the vehicle 60 is between the measurement poles A and B, the light receivers Sa (n) and Sb (n) at positions lower than the light receiver Sa22 at a position lower than the ceiling 60a of the leading driver's seat. The detection light to be received at is blocked by the vehicle 60. Therefore, the detection light is not received by the light receivers Sa (n) and Sb (n) at a position lower than the ceiling 60a, and the detection light is not received at the light receivers Sa (n) and Sb (n) at a position higher than the ceiling 60a. Light is received.

  Further, since whether or not the detection light is received by each light receiver S is transmitted by an electric signal, the vehicle height specifying unit M22 can specify the vehicle height. In the example of the figure, the height of the ceiling 60a is between the height of the light receiver Sb21 at the lowest position where light is received and the height of the light receiver Sa22 at the highest position where light is not received. I understand. At this time, since the two light emitters Tc22 and Tc22 at the height between the light receiver Sb21 and the light receiver Sa22 are not emitting light, the height between the light receiver Sb21 and the light receiver Sa22 is not increased. The detailed height cannot be detected.

  That is, in step S130, the vehicle height can be measured in increments of 6 cm, and it cannot be specified how much the actual vehicle height is within 6 cm, which is the distance between the light receiver Sb21 and the light receiver Sa22. In step S130, it can be specified that the vehicle height is between the light receiver Sb21 and the light receiver Sa22. Here, the height of the light receiver Sa22 at the highest position that is not received is specified as the measured value M. Remember. However, as the measurement value M, not only the position of the light receiver S at the highest position where light is not received but also the height of the light receiver S at the lowest position where light is received may be applied. An average value may be applied.

  Here, in step S120, all the light emitters Ta (n) and Tb (n) emit light simultaneously. For example, consider the case where all the light emitters Ta (n) emit light simultaneously. At this time, if the detection light is incident on the light receiving device Sa (n) that does not face the light receiving device, the light receiving device Sa (n) that does not face the light may cause a false detection. Specifically, referring to FIG. 2, when the detection light emitted from the light emitter Ta0 diffuses and enters the light receiver Sa4, the vehicle height of the passing vehicle 60 is higher than the height of the light receiver Sa4. Although the light receiver Sa4 is not supposed to receive light, the detection light is received. In such a case, it becomes impossible to accurately measure the vehicle height. In the light receivers Sb (n) and Sc (n) that do not emit light at the same time, the signal indicating whether or not the detection light is received is cut off during the light emission period of the light emitter Ta (n) so that the light reception is not detected. Therefore, false detection does not become a problem.

  In the present embodiment, the traveling directions of detection light transmitted and received at the light emitter Ta (n) and the light receiver Sa (n) to which the subscript a is added and which are closest to the height direction are opposite to each other. It is like that. Therefore, erroneous detection does not become a problem between the light emitting devices Ta (n) and the light receiving device Sa (n) that are opposite to each other in the height direction. For example, in FIG. 2, since the traveling directions of the detection light between the light emitter Ta2 and the light receiver Sa2 and the detection light between the light emitter Ta4 and the light receiver Sa4 are opposite, the light emitter Ta that emits light simultaneously. In the light receiver Sa (n) facing (n) and closest to the height direction in the light receiver Sa2 and the light receiver Sa4, erroneous detection does not cause a problem. Although the light emitting device Ta (n) to which the subscript a is added has been described above, the light emitting device Tb (n) to which the subscript b is added is also arranged in the same manner, so that erroneous detection can be prevented.

  By the way, when the vehicle 60 does not reach the measurement poles A and B in FIG. 6, detection light is detected by all the light receivers Sa (n) and Sb (n). , Sb (n) makes it possible to recognize that the vehicle 60 is approaching because no detection light is received. On the contrary, when the detection light is received by one of the light receivers Sa (n) and Sb (n) and then the detection light is detected by all the light receivers Sa (n) and Sb (n) It can be recognized that the vehicle 60 has passed through the measurement poles A and B. When the vehicle 60 is not approaching the measurement poles A and B, the measurement value M is specified as 0.

  When the vehicle height is specified in step S130 as described above, the two light emitters Tc (n) immediately above the height of the measured value M are caused to emit light in step S140. In the example shown in FIG. 6, since the height of the light receiver Sa22 is the measurement value M, the two light emitters Tc22 and Tc22 immediately above the light receiver Sa22 are caused to emit light simultaneously as indicated by a double line. That is, the heights of the light receiving devices Sa (n) and Sb (n) at the lowest position received in steps S120 to S130 and the light receiving devices Sa (n) and Sb (n) at the highest position where light is not received. The light emitters Tc (n) between the heights are caused to emit light, and the other light emitters T are not emitted. In step S150, it is determined whether or not there is a light that has not been received by the light emitter Tc (n) emitted in step S140. When there is a light receiver Sc (n) that does not receive light, the height of the light emitting device Tc (n) that does not receive light is updated as the measured value M.

  Thereby, between the height of the light receivers Sa (n) and Sb (n) at the lowest position where light is received and the height of the light receivers Sa (n) and Sb (n) at the highest position where light is not received. The vehicle height specified in step S130 can be measured in detail within the same range of heights. In the example shown in FIG. 6, it is known in step S130 that the vehicle height is between the light emitters Tc22 and Sc22, and the light emitters Tc22 and Tc22 during this period are simultaneously emitted to measure the vehicle height in detail. In this case, since the light receiving device Sc (n) not receiving light is the lower light receiving device Sc22, the height of the lower light receiving device Sc22 is updated to the measured value M. On the other hand, if there is no light emitter Tc (n) that does not receive light, it can be seen that the vehicle height is not higher than the measured value M stored in step S130, so the measured value M stored in step S130 is held as it is.

  That is, in steps S120 to S130, the vehicle height range is roughly measured by thinning the light emitter T to emit light, and in steps S140 to S160, the measured vehicle height range is measured in detail. In steps S120 to S130, measurement in increments of 6 cm can be performed. In steps S140 to S160, measurement in increments of 2 cm can be performed. Finally, measurement results in increments of 2 cm can be output. That is, it can be said that steps S120 to S130 correspond to the first measurement timing according to the present invention, and steps S140 to S160 correspond to the second measurement timing according to the present invention.

  By doing in this way, in steps S150 to S160, since only the necessary light emitter T can emit light, the time required for light emission can be shortened and the measurement can be performed at high speed. Furthermore, in this embodiment, since two measurement heights are detected simultaneously by causing two light emitters Tc (n) to emit light simultaneously, higher-speed measurement is possible. Although the above-described erroneous detection becomes a problem by causing two light emitters Tc (n) to emit light simultaneously, the light emitters Ta (n) and Tb (n) and the light receivers Sa (n) and Sb described above. Similarly to (n), each light emitting device Tc (n) and each light emitting device Tc (n) and each light receiving device Sc (n) are set so that their traveling directions are opposite to each other. Since the light receiver Sc (n) is arranged, erroneous detection does not cause a problem.

  In the example of FIG. 6, the upper light emitter Tc22 and the lower light emitter Tc22 that are simultaneously emitted in step S140 are arranged on different measurement poles A and B. There is no false detection due to the opposite direction. In this embodiment, the time required for light emission / light reception is 4 ms, and it is necessary to cause the light emitter Ta (n), the light emitter Tb (n), and the light emitter Tc (n) to emit light. The number of times is three. Therefore, the time required for steps S120 to S160 is 4 ms × 3 times = 12 ms.

  On the other hand, in the case where the present invention is not applied, the vehicle height cannot be measured in increments of 2 cm unless all the light emitters T arranged in increments of 2 cm are caused to emit light for measurement. As a method of causing all the light emitters T arranged in 2 cm increments to emit light, it is conceivable to cause the light emitters T to emit light sequentially and to cause a plurality of light emitters T to emit light simultaneously. In the former, all of the light emitters T arranged in increments of 2 cm must emit light in order, and a predetermined activation time must be ensured between each light emission. Therefore, it is enormous to complete detection for all measurement heights. Takes a long time. In the latter case, erroneous detection becomes a problem as described above.

  In step S170, the comparison unit M24 acquires the memory value J stored in the vehicle height storage unit 22a. In step S180, the measured value M is compared with the memory value J. If the measured value M is equal to or greater than the memory value J, the vehicle height storage unit sets the measured value M as a new memory value J in step S185. 22a is updated.

  Since the memory value J is initialized to 0 in step S110, the measured value M is always updated and stored even if no vehicle is detected in the first stage. When the measured value M is updated in the vehicle height storage unit 22a in step S185, the processes after step S120 are repeatedly executed. Therefore, when the vehicle is not approaching and the measured value M is repeatedly specified as 0 in step S130, 0 is continuously stored as the memory value J in the vehicle height storage unit 22a.

  On the other hand, if it is determined in step S180 that the measured value M is smaller than the memory value J, whether or not the measured value M is 0 is determined in step S190. If the measured value M is not 0, the processes after step S120 are repeated. If the measured value M is 0, the memory value J is output to the display 26 and the printer 28 in step S195. When the memory value J is output, the process returns to step S110 to initialize the memory value J of the vehicle height storage unit 22a to 0, and the processes after step S120 are repeatedly executed.

  In any case, the processing from steps S120 to S180 is repeated. Here, in this embodiment, since the time required for light emission in steps S120 to S160 is 12 ms as described above, the time required to perform steps S120 to S180 for one cycle is also 12 ms. Note that arithmetic processing other than light emission is simple and does not affect the above cycle. That is, the vehicle height is measured intermittently at a cycle of 12 ms, and the measured value M of the vehicle height is specified at steps S130 and S160 in each cycle.

  In this way, the vehicle height can be measured over the entire length of the vehicle 60 traveling at a predetermined speed. Therefore, even after the head of the vehicle 60 passes the measurement poles A and B, the height can be measured when the ceiling 60b of the loading platform having the highest height passes.

  Further, by executing step S180, only the measurement value M indicating the vehicle height higher than the memory value J can be stored as the new memory value J. Therefore, the highest vehicle height is always stored as the final memory value J. In the example of FIG. 6, when the head of the vehicle 60 passes, the heights of the light emitter Tc22 and the light receiver Sc22 are stored as measured values M, and then the light emitter Tc7 and light receiver when the ceiling 60b of the cargo bed passes. The height of Sc7 can be stored. In addition, after the head of the vehicle 60 passes the measurement poles A and B, the maximum vehicle height can be obtained if the vehicle height is detected at a position higher than the head of the vehicle 60. Therefore, a non-zero measurement value M is detected. After that, the power consumption can be suppressed by not causing the light emitter T at a position lower than the measured value M to emit light.

  However, since it is meaningless to compare the maximum vehicle height between different vehicles in the above, it is determined whether or not the tail of the vehicle 60 has passed in steps S180 and S190. In step S195, the memory value J is output to the display 26 and the printer 28, and then the memory value J is initialized to zero. In this way, it is possible to notify the user of the final measurement result of the vehicle height.

  When the rear end of the vehicle 60 passes, the memory value J indicating the vehicle height measured before that is a value of any vehicle height that is not 0, while the measured value M is 0. Therefore, in step S180, it is determined that the measured value M is smaller than the memory value J, and in step S190, it is determined that the measured value M is 0. Therefore, it is possible to specify whether or not the tail of the vehicle 60 has passed by executing steps S180 and S190. The method for initializing the memory value J between the vehicles is not limited to the above. For example, when the measured value M continues to be zero over a predetermined period, the memory value J is determined to be between the vehicles, and the memory value J is initialized. Alternatively, the memory value J may be determined to be the head of the vehicle when the memory value J is updated from 0 to a value other than 0, and the memory value J may be initialized.

  Further, since the vehicle height can be measured in a short time of 12 ms, fine vehicle height measurement in the vehicle length direction is possible even when the traveling speed of the vehicle 60 is fast. For example, a vehicle traveling at a speed of 72 km can measure at intervals of 24 cm in the vehicle length direction, and a vehicle traveling at a speed of 36 km per hour can be measured at intervals of 12 cm in the vehicle length direction. Therefore, since the measurement can be performed without limiting the traveling speed of the vehicle, even if it is installed on a general road, the flow of traffic is not hindered.

(2) Second embodiment:
FIG. 7 shows the measurement poles A and B of the vehicle height measurement device according to the second embodiment as viewed from the inside (vehicle passage 50). In addition, since the external appearance of the vehicle height measuring device concerning 2nd embodiment is the same as that of previous embodiment, description is abbreviate | omitted. Further, the hardware configuration and software configuration other than the arrangement of the light emitters and light receivers in the measurement poles A and B are the same as those in the previous embodiment, and thus the description thereof is omitted. In the figure, light emitters Ta0, Tc1, Tb1, Tc1,... Are arranged on the measurement pole B with the light emitting portions facing inward. Then, the light receivers Sa0, Sc1, Sb1, Sc1... Are arranged on the light receiving unit on the measurement pole A so as to face the light emitters Ta0, Tc1, Tb1, Tc1. Is arranged facing inward. The measuring pole A is also provided with light emitters Ta1, Ta3... And the measuring pole B is provided with light receivers Sa1, Sa3.

  Also in this embodiment, the distance between the light emitters T adjacent to each other in the height direction, the light receivers S, and the distance between the light emitters T and S is 2 cm in both the measurement poles A and B. . Therefore, the height interval of the detection light emitted from each light emitter T is also 2 cm. The light emitter T and the light receiver S are classified into blocks represented by X1, X2, X3... X (n). Note that n is a natural number and means a block number. Each block X (n) is composed of four sets of opposing light emitters T and light receivers S that are continuous in the height direction. Therefore, in each block X (n), it is possible to receive and emit detection light at the second, third, and fourth positions from the uppermost position.

  Each light emitter T and light receiver S is indicated by adding a, b, c as a subscript and the number n of each block X (n). In each block X (n), c is added as a subscript to the light emitting device T and the light receiving device S that face each other at the third position from the top, and face each other at the second position from the top. The light emitter T and the light receiver S are suffixed with b. Then, a is added as a subscript to the light emitter T and the light receiver S facing each other at the lowest position (fourth stage from the top) in each block X (n). That is, a pair of light emitters Ta (n) and light receivers Sa (n) facing each other, and a light emitter Tb (n) to which b is added as a subscript at the middle height between the closest ones in the height direction. ) And the light receiver Sb (n). For example, the light emitter Tb2 and the light receiver Sb2 are disposed at the middle height of the pair of the light emitter Ta1 and the light receiver Sa1 and the pair of the light emitter Ta2 and the light receiver Sa2.

  All the light emitters T other than the light emitter Ta (n) facing each other at the lowest position in each block X (n) are disposed on the measurement pole B. Similarly, all the light receivers S other than the light receiver Sa (n) are disposed on the measurement pole A. On the other hand, in the block X (n) in which the block number n is an odd number, the light receiver Sa (n) is disposed on the measurement pole B, and the light emitter Ta (n) is disposed on the measurement pole A. In the block X (n) in which the block number n is an even number, the light receiver Sa (n) is disposed on the measurement pole A, and the light emitter Ta (n) is disposed on the measurement pole B.

  That is, the detection light transmitted and received in the light emitter Ta (n) and the light receiver Sa (n) to which the subscript a is added, and the traveling directions closest to the height direction are opposite to each other. Yes. For example, in the light emitter Ta1 and the light receiver Sa1, the detection light travels from the measurement pole A toward the measurement pole B, whereas in the light emitter Ta2 and the light receiver Sa2 closest thereto, the detection light is transmitted to the measurement pole B. To the measuring pole A.

  FIG. 8 shows the flow of measurement processing in the control unit 20. In the figure, first, in step S1110, a memory value J indicating the vehicle height stored in the vehicle height storage unit 22a assigned to the RAM 22 is initialized to zero. In step S1120, all the light emitters Ta (n) emit light simultaneously. That is, all the light emitting devices Ta (n) at the lowest position in each block X (n) can emit light simultaneously. In other words, it is possible to emit light by thinning the light emitter T in the height direction so that there are light emitters Tb (X) or Tc (X) that do not emit light three by three between the light emitting light emitters Ta (n). . In the present embodiment, since the interval between the light receiver S and the light emitter T adjacent in the height direction is 2 cm, the detection light is emitted at intervals of 8 cm in the height direction.

  While light is emitted in step S1120, in step S1130, the presence or absence of light reception is detected by each light receiver S, and the vehicle height is specified. Specifically, the vehicle height is between the height of the light receiving device Sa (n) at the lowest position where light is received and the height of the light receiving device Sa (n) at the highest position where light is not received. I understand. That is, in step S1130, the vehicle height can be specified in increments of 8 cm. However, although it is possible to measure the vehicle height in steps of 8 cm in step S1130, it is not possible to specify how much the actual vehicle height is in 8 cm. In step S1130, it can be specified that the height is between the height of the light receiving device Sa (n) at the lowest position where light is received and the height of the light receiving device Sa (n) at the highest position where light is not received. . In the example shown in FIG. 9, the height of the light receiving device Sa16 at the highest position that has not been received is specified as the measured value M and stored.

  When the vehicle height is specified in steps of 8 cm in step S1130 as described above, the light emitter Tb (n) immediately above the height of the measured value M is caused to emit light in step S1140. In the example shown in FIG. 9, since the height of the light receiver Sa16 is the measurement value M, the light emitter Tb16 immediately above the light receiver Sa16 is caused to emit light. The other light emitters T do not emit light. In step S1150, it is determined whether or not the detection light of the light emitter Tb (n) emitted in step S1140 is received by the opposing light receiver Sb (n).

  If no light is received by the light receiver Sb (n), the height of the light emitter Tb (n) emitted in step S1140 is updated as the measured value M in step S1152. That is, assuming that the vehicle height is higher than the measurement value M stored in step S1130, the height of the light emitter Tb (n) is updated as the measurement value M. Then, in step S1155, it is assumed that the vehicle height is at a position higher than the measured value M updated and stored in step S1152 and lower than the light receiving device Sa (n) at the highest position received in step S1130. The light emitter Tc (n) immediately above the device Tb (n) is caused to emit light. The other light emitters T do not emit light.

  On the other hand, if it is determined in step S1150 that the light receiver Sb (n) has received light, the light emitter Tc (n) immediately below the light emitter Tb (n) is caused to emit light in step S1158. That is, assuming that the vehicle height is at a position higher than the measured value M stored in step S1130 and lower than the light emitter Tb (n) emitted in step S1140, immediately after the light emitter Tb (n). The lower light emitter Tc (n) is caused to emit light. The other light emitters T do not emit light. In the example shown in FIG. 9, since the detection light is received by the light receiver Sb16, the light emitter Tc16 immediately below the light receiver Sb16 is caused to emit light in step S1158.

  In step S1160, it is determined whether or not the detection light from the light emitter Tc (n) emitted in steps S1155 and S1158 is detected by the opposing light receiver Sc (n). If no light is received, the height of the light emitter Tc (n) emitted in steps S1155 and S1158 is updated as a measured value M in step S1165. In the example shown in FIG. 9, since the detection light from the light emitter Tc16 immediately below the light receiver Sb16 is not detected, the height of the light emitter Tc16 is updated as the measurement value M.

  In this way, the vehicle height can be finally measured in 2 cm increments. First, in steps S1120 to S1130, by performing measurement thinned in the height direction, the height of the light receiving device Sa (n) at the lowest position received in step S1130 and the light receiving device at the highest position where light was not received. It can be seen that the vehicle height is in the range of 8 cm between the heights of Sa (n). That is, steps S1120 to S1130 constitute the first measurement timing referred to in the present invention.

  In Steps S1140 to S1152, the light emitting device Tb (n) having the center height in the above range of 8 cm is caused to emit light so that the vehicle height is in the range of 4 cm on the upper side of the above range of 8 cm or on the lower side of 4 cm. You can specify whether it is in range. That is, steps S1140 to S1152 constitute the second measurement timing referred to in the present invention. When the vehicle height is in the range of 4 cm above the above range of 8 cm, the height of the light receiver Tb (n) is updated to the measured value M in step S1152.

  Further, in steps S1155 to 1165, by causing the light emitter Tc (n) immediately above or immediately below the light emitter Tb (n) to emit light, in the upper 4 cm range or the lower 4 cm in the above range of 8 cm. The vehicle height can be specified in more detail. If it is determined in step S1160 that the vehicle height is higher than the vehicle height stored as the measured value M so far, the height is updated as the measured value M in step S1165. Yes. That is, steps S1155 to 1165 constitute the third measurement timing referred to in the present invention.

  In the second measurement timing and the third measurement timing, only the light emitter T having a height that is expected to have a vehicle height can be made to emit light. It is possible to realize a small vehicle height measurement. In this embodiment, the time required for light emission / light reception is 4 ms, and it is necessary to cause the light emitter Ta (n), the light emitter Tb (n), and the light emitter Tc (n) to emit light. The time required for S1165 is 4 ms × 3 times = 12 ms. In addition, since the light emitters T are caused to emit light one by one at the second measurement timing and the third measurement timing, and the plurality of light emitters T are not simultaneously emitted, erroneous detection does not cause a problem. Therefore, accurate vehicle height measurement can be realized.

  However, it can be said that the vehicle height is specified in steps of 4 cm from step S1120 to S1130 and steps S1140 to S1152. Therefore, steps S1120 to S1130 and steps S1140 to S1152 can be referred to as the first measurement timing. In that case, steps S1155 to 1165 constitute the second measurement timing. In other words, the processing at the second and third measurement timings may be repeated any number of times, and the interval for the thinning measurement is set to be wide at first, and the detection range is gradually narrowed multiple times at the same interval. Also good.

  Since step S1170 and subsequent steps are the same as those in the previous embodiment, description thereof will be omitted. Even in the present embodiment, the vehicle height can be measured in a short time of 12 ms, so that even when the traveling speed of the vehicle 60 is high, the vehicle height can be measured finely in the vehicle length direction. For example, a vehicle traveling at a speed of 72 km can measure at intervals of 24 cm in the vehicle length direction, and a vehicle traveling at a speed of 36 km per hour can be measured at intervals of 12 cm in the vehicle length direction. Therefore, since the measurement can be performed without limiting the traveling speed of the vehicle, even if it is installed on a general road, the flow of traffic is not hindered.

(3) Third embodiment:
FIG. 10 shows the appearance of the vehicle height measuring device according to the present invention as seen from an oblique direction. In the figure, a pair of detection measurement poles A and B are erected on the outer side in the width direction of the vehicle passage 50, and a pair of measurement measurement poles C and D are similarly erected downstream thereof. The vehicle 60 can pass between the detection measurement poles A and B and the measurement measurement poles C and D, and the detection measurement poles A and B and the measurement measurement poles C and D are It is formed sufficiently higher than the vehicle 60. In addition, the distance between the measurement measurement poles A and B and the measurement measurement poles C and D is longer than the vehicle length of the vehicle 60.

  FIG. 11 shows the detection measurement poles A and B and the measurement measurement poles C and D as viewed from the inside (vehicle passage 50). In the figure, on the detection measuring pole B, light emitters Ta1, Tb1, Ta3, Tb3... Ta (2n-1), Tb (2n-1) indicated by ● are arranged with the light emitting part facing inward. Has been. Note that n means a natural number. In addition, light detectors Sa2, Sb2, Sa4, Sb4... Sa (2n), Sb (2n) indicated by ◯ are also arranged on the detection measuring pole B with the light receiving portions facing inward.

  That is, two light emitters T are continuously arranged in the height direction. Each of them is referred to as a light emitter block P. A light emitter block composed of light emitters Ta1 and Tb1 is referred to as a light emitter block P1, and a light emitter block composed of Ta (2n-1) and Tb (2n-1) is represented as a light emitter block P (2n-1). ). Similarly, the photoreceiver S also constitutes two photoreceiver blocks that are continuous in the height direction, and each photoreceiver block is denoted as a photoreceiver block Q (2n). The light emitters T and light receivers S are alternately arranged in units of blocks, and are arranged in the order of P1, Q2, P3, Q4... P (2n-1), Q (2n) from the top. . The intervals h between the light emitter T and the light emitter T adjacent to each other in the height direction, the light receiver S and the light receiver S, and the distance between the light emitter T and the light receiver S are all 8 cm.

  On the other hand, a light emitter T and a light receiver S are also arranged on the detection measurement pole A opposite to the detection measurement pole B configured as described above with the light emitting portion and the light receiving portion facing inward. In the detection measuring pole A, the same light emitters Ta1, Tb1, Ta3, Tb3... Ta (2n-1), Tb (2n-1) provided in the detection measuring pole B are opposed to each other. Light receivers Sa1, Sb1, Sa3, Sb3... Sa (2n-1), Sb (2n-1) are arranged at a height. Therefore, the detection light emitted substantially horizontally from each of the light emitters Ta1, Tb1, Ta3, Tb3... Ta (2n-1), Tb (2n-1) provided in the detection measuring pole B is detected. The light receivers Sa1, Sb1, Sa3, Sb3... Sa (2n-1) and Sb (2n-1) of the measurement pole A can receive light.

  Similarly, the detection measuring poles A are provided at the same height so as to face the light receiving devices Sa2, Sb2, Sa4, Sb4... Sa (2n), Sb (2n) provided in the detection measuring pole B. The light emitters Ta2, Tb2, Ta4, Tb4... Ta (2n), Tb (2n) are arranged. Accordingly, in the detection measuring pole A, the light emitter block P and the light receiver block Q in which two light emitters T and two light receivers S are continuously arranged in the height direction are alternately arranged. Q1, P2, Q3, P4... Q (2n-1), P (2n).

  On the other hand, in the measurement measurement poles C and D, the light emitter T and the light receiver S are arranged in the same manner as the measurement measurement poles A and B. That is, the light emitter block P and the light receiver block Q in which two light emitters T and two light receivers S are continuously arranged in the height direction are alternately arranged. However, in the measurement measuring poles C and D, the light emitter T and the light emitter T adjacent to each other in the height direction, the light receiver S and the light receiver S, and the interval l between the light emitter T and the light receiver S are all. It is 2 cm. In the center of the figure, the detection measurement poles A and B are shown enlarged in the height direction at the same scale as the measurement measurement poles C and D. In the detection measurement poles A and B, the distance between the light emitter T and the light receiver S adjacent in the height direction is four times that of the measurement measurement poles C and D. That is, the measurement poles C and D for detecting the vehicle height using the light emitter T and the light receiver S can obtain the vehicle height with four times the accuracy in the height direction as compared with the measurement poles A and B for detection. Can be measured.

  The light emitter T outputs substantially horizontal detection light from the light emitting portion toward the light receiver S facing the light emitter T. Also, the output detection light can be of various wavelengths. The light receiver S is a photoelectric element that receives detection light from the light receiving unit and generates an electrical signal corresponding to the detection light. In the light receiver S, a filter circuit may be provided in order to reduce noise due to light other than the detection light. A circuit for amplifying the detected electrical signal may be provided.

  FIG. 12 shows a hardware configuration of the vehicle height measuring device 110. In the figure, a detection unit 120 corresponding to the detection measurement poles A and B and a measurement unit 130 corresponding to the measurement measurement poles C and D are provided. A bus 120 a provided in the detection unit 120 includes a CPU 121, a ROM 123, a RAM 122, a transmitter 128 via an interface (I / F) 129, and detection measurement poles A and B via an I / O 125. And are connected to each other. And CPU121 controls each part according to the program written in ROM123, using RAM122 as a work area. As described above, since each of the detection measurement poles A and B is provided with both the light emitter T and the light receiver S, the I / O 125 outputs a signal for causing the light emitter T to emit light. In addition to outputting to each of B, an electric signal indicating the light receiving state of the light receiver S is input from the detection measuring poles A and B.

  On the other hand, a bus 130a provided in the measurement unit 130 includes a CPU 131, a ROM 133, a RAM 132, a display 136 via an interface (I / F) 137, a printer 138 via an I / F 139, and an I / F. A receiver 141 via / F140 and measurement measuring poles C and D via I / O 135 are connected to each other. The display 136 displays the measured vehicle height, and the printer 138 prints and records the vehicle height on a recording medium such as paper. The receiver 141 can receive predetermined data transmitted from the transmitter 128 provided in the detection unit 120, and the I / F 140 handles the received data by the CPU 131 or the like. Convert to a possible signal. Similarly to the I / O 125 in the detection unit 120 described above, the I / O 135 outputs a signal for causing the light emitter T to emit light to each of the measurement measurement poles C and D, and indicates the light reception state of the light receiver S. An electric signal is input from measurement poles C and D for measurement.

  In this embodiment, the control units for controlling the detection measurement poles A and B and the measurement measurement poles C and D are individually provided. However, the detection measurement poles A and B and the measurement measurement pole are provided. The C and D control units may be shared. In addition, the data exchange between the detection measurement poles A and B and the measurement measurement poles C and D is performed wirelessly, but may be performed by wire. In addition, when performing by radio | wireless, installation of the vehicle height measuring apparatus 110 becomes easy. In addition, the display 136 and the printer 138 are connected to the bus 130a of the measurement unit 130, but a wireless transmission / reception device or the like is interposed between the display unit 136 and the printer 138 so that the installation location of the display 136 and the printer 138 has a degree of freedom. May be. If the measurement result is not only output to the output device such as the display 136 and the printer 138 but also stored as data, a hard disk or the like may be provided.

  FIG. 13 shows a software configuration of the vehicle height measuring device 110. In the figure, the detection unit 120 is composed of modules of a light emission control unit M121, a vehicle height specifying unit M122, a comparison unit M124, and a transmission unit M126. The light emission control unit M121 executes light emission control of the light emitter T provided in each of the detection measurement poles A and B, and the vehicle height specifying unit M122 includes a light receiver S provided in each of the detection measurement poles A and B. A signal indicating the light receiving state is input, and the vehicle height is specified as the detected value K from the signal. The comparison unit M124 compares the detection value K specified by the vehicle height specification unit M122 with the memory value J indicating the maximum vehicle height stored in the detection vehicle height storage unit 122a assigned to the RAM 122, and A process for updating the higher one in the RAM 122 is executed. The transmission unit M126 executes a process of acquiring the memory value J indicating the maximum vehicle height from the RAM 122 and transmitting it to the measurement unit 130.

  On the other hand, the measurement unit 130 includes modules of a light emission control unit M131, a vehicle height specifying unit M132, a comparison unit M134, a receiving unit M136, and an output unit M137. The receiving unit M136 receives the memory value J transmitted from the detection unit 120, and outputs the same information to the light emission control unit M131. The light emission control unit M131 controls the light emission of the light emitter T included in each of the measurement measurement poles C and D based on the memory value J. The vehicle height specifying unit M132 and the comparison unit M134 perform the same processing as the vehicle height specifying unit M122 and the comparison unit M124 in the detection unit 120. Then, the output unit M137 outputs the memory value I stored in the detection vehicle height storage unit 132a finally assigned to the RAM 132 as the maximum vehicle height to an output device such as the display 136 and the printer 138.

  FIG. 14 shows the flow of detection processing in the detection unit 120. In the figure, first, in step S2110, a memory value J indicating the vehicle height stored in the detection vehicle height storage unit 122a assigned to the RAM 122 is initialized to zero. The vehicle height value stored in the detection vehicle height storage unit 122a is hereinafter simply referred to as a memory value J. In step S2120, the light emission controller M121 causes the light emitters Ta1, Ta2, Ta3, Ta4... Ta (2n-1) and Ta (2n) provided in each of the detection measurement poles A and B to emit light simultaneously. After 4 ms (milliseconds), the light emitters Tb1, Tb2, Tb3, Tb4... Tb (2n−1), Tb (2n) are caused to emit light simultaneously. In other words, the upper light emitter T among the light emitter blocks P1 to P (2n) is caused to emit light first, and the lower light emitter T of each light emitter block P is caused to emit light after 4 ms. The light emission period of 4 ms is a start-up time until the light emitter T emits light stably, and is a time necessary for performing stable detection.

  FIG. 15 shows a state in which the light emitter T emits light as seen from the traveling direction of the vehicle. In the figure, the light emitters Ta1, Ta2, Ta3, Ta4... Ta (2n-1), Ta (2n) emit light simultaneously as indicated by solid lines. After 4 ms, the light emitters Tb1, Tb2, Tb3, Tb4... Tb (2n-1), Tb (2n) emit light simultaneously as indicated by broken lines. In this way, the detection light indicated by the solid line and the broken line is emitted alternately. Therefore, the time required for emitting the detection light at all the measurement heights where the light emitter T is disposed in the height direction in steps of 8 cm is 4 ms × 2 times 8 ms.

  For example, assuming that the head of the vehicle 60 is between the detection measuring poles A and B, light is emitted from the light emitters Ta13, Ta (2n), Tb (2n), etc., which are lower than the ceiling 60a of the leading driver's seat. The detected light is blocked by the vehicle 60 and does not reach the light receivers Sa13, Sa (2n), Sb (2n) and the like corresponding thereto. On the other hand, the detection light emitted from the light emitter Tb12 higher than the ceiling 60a reaches the light receiver Sb12. Thereby, it can be determined that the height of the vehicle is a value between the light receiver S at the highest position where the detection light is not received and the light receiver S at the lowest position where the detection light is received.

  Of course, when the vehicle 60 does not pass through the detection measurement poles A and B, the detection light is detected by all the light receivers S. Therefore, the vehicle 60 passes because no detection light is received by any one of the light receivers S. It is possible to recognize that. On the contrary, when the detection light is received by any one of the light receivers S and then the detection light is detected by all the light receivers S, the vehicle 60 passes through the detection measuring poles A and B. It can be recognized that it has been cut.

  In step S2130, the vehicle height specifying unit M122 acquires the detection state of each light receiver S and specifies the vehicle height. Specifically, the height of the light receiver S at the highest position where the detection light is not received is specified as the vehicle height. Of course, as described above, the vehicle 60 may not reach the detection measurement poles A and B. In this case, the vehicle height is specified to be zero. In addition, the measured value of the vehicle height obtained in step S2130 is hereinafter simply referred to as a detected value K. In step S2140, the comparison unit M124 acquires the memory value J stored in the detection vehicle height storage unit 122a. In step S2150, if the detected value K is equal to or greater than the memory value J by comparing the detected value K with the memory value J, the detected vehicle height storage unit 122a is updated in step S2160. .

  Since the memory value J is initialized to 0 in step S2110, the detected value K is always updated and stored even if no vehicle is detected in the first stage. When the detection value K is updated in the detection vehicle height storage unit 122a in step S2160, the processes in and after step S2120 are repeatedly executed. Therefore, when the vehicle is not approaching and the detection value K is repeatedly specified as 0 in step S2130, 0 is continuously stored as the memory value J in the detection vehicle height storage unit 122a. .

  On the other hand, if it is determined in step S2150 that the detected value K is smaller than the memory value J, whether or not the detected value K is 0 is determined in step S2170. If the detected value K is not 0, the processes after step S2120 are repeated. If the detected value K is 0, the transmission unit M126 causes the measuring unit 130 to output the memory value J in step S2180. When the memory value J is output, the process returns to step S2110 to initialize the memory value J of the detection vehicle height storage unit 122a to 0, and the processes after step S2120 are repeatedly executed.

  In any case, the processing from step S2120 to S2170 is repeated. That is, light is emitted intermittently from the light emitter T at a cycle of 8 ms, and the detected value K of the vehicle height is specified at step S2130 in each cycle. In this way, the vehicle height can be measured over the entire length of the vehicle 60 traveling at a predetermined speed. Therefore, even after the head of the vehicle 60 passes the detection measuring poles A and B, the height can be measured when the ceiling 60b of the loading platform having the highest height passes. In addition, since the process of step S2130-S2180 is not complicated, it hardly affects the light emission period 8ms of the light emitter T.

  Further, only the detected value K indicating the vehicle height higher than the memory value J is stored as the new memory value J by executing step S2150. Therefore, the highest vehicle height is always stored as the final memory value J. However, since it is meaningless to compare the maximum vehicle heights between different vehicles, it is determined whether or not the tail of the vehicle 60 has passed in steps S2150 and S2170. The memory value J is output as the vehicle height, and then the memory value J is initialized to zero. In this way, only the maximum vehicle height can be output to the measurement unit 130, and the vehicle height of the vehicle passing thereafter can be distinguished and measured.

  When the rear end of the vehicle 60 passes, the memory value J indicating the vehicle height measured before that time is any vehicle height value that is not 0, while the detected value K is 0. Therefore, in step S2150, it is determined that the detected value K is smaller than the memory value J, and in step S2170, it is determined that the detected value K is 0. Therefore, it is possible to specify whether or not the tail of the vehicle 60 has passed by executing steps S2150 and S2170. The method for initializing the memory value J between the vehicles is not limited to the above. For example, when the detection value K continues to be 0 over a predetermined period, it is determined that the vehicle value is between the vehicles, and the memory value J is initialized. Alternatively, the memory value J may be determined to be the head of the vehicle when the memory value J is updated from 0 to a value other than 0, and the memory value J may be initialized.

  According to the configuration described above, the light emitter T can emit light at all measurement heights in a short time of 8 ms. Therefore, even when the traveling speed of the vehicle 60 is high, it is possible to measure the vehicle height in the vehicle length direction. For example, a vehicle traveling at a speed of 72 km can measure at intervals of 16 cm in the vehicle length direction, and a vehicle traveling at a speed of 36 km per hour can be measured at intervals of 8 cm in the vehicle length direction. Therefore, since the measurement can be performed without limiting the traveling speed of the vehicle, even if it is installed on a general road, the flow of traffic is not hindered.

  As described above, when many light emitters T emit light at the same time, the measurement speed increases, but the detection light emitted from a plurality of light emitters T that emit light simultaneously enters the same light receiver S. Prone to detection problems. In this case, it is impossible to specify which height of the detection light is blocked, and accurate vehicle height measurement cannot be performed. Note that such a problem does not occur if the detection light travels horizontally from the light emitter T. However, since the light has the property of being diffracted and refracted in the path, it is inevitable that the above problems occur.

  On the other hand, in the present invention, the light emitter block P and the light receiver block Q are alternately arranged in the height direction, so that a set of the light emitter T and the light receiver S that emit light at the same time and is the most in the height direction. The traveling directions of the detection light between the close ones are opposite to each other. Therefore, it is possible to prevent erroneous detection as in the embodiment described above.

  For example, the light receiver S that should originally detect the detection light emitted from the light emitter Ta3 disposed on the detection measurement pole B shown in FIG. 11 is the light receiver Sa3. The closest light receivers S that are likely to be erroneously detected when the detection light reaches the opposing detection measurement pole A are the light receivers Sa1 and Sa5 that simultaneously receive light. However, the distance between the light emitter Ta3 and the light receiver Sa1 and the light receiver Sa5 is as wide as 8 cm × 4 = 32 cm, and it is not considered that the detection light is diffracted and refracted so far. Since the light emitters Ta2, Tb2, Ta4, and Tb4 interposed between them are not the light receiver S, the light emitters Ta2, Tb2, Ta4, and Tb4 cannot be erroneously detected. Therefore, erroneous detection of detection light can be prevented.

  FIG. 16 shows the flow of measurement processing in the measurement unit 130. In the figure, first, in step S2205, the receiving unit M136 accepts the input of the memory value J from the detection unit 120. When the input of the memory value J is accepted in step S2210, the light emission control unit M131 identifies the light emitter T that emits light at the measurement measurement poles C and D from the memory value J in step S2215. For example, as shown in FIG. 11, when a memory value J corresponding to a measurement result received by the light receiver Sa3 of the detection measurement poles A and B and not received by the light receiver Sb3 is input, the measurement measurement pole C , D, the light emitter T corresponding to the height between the light receiver Sa3 and the light receiver Sb3 is specified. Note that the light emitting device T specified here does not need to have a height strictly corresponding to the memory value J, and may be specified with a margin above and below. For example, you may make it identify the light-emitting device T in the area | region F which gave the margin of 4 cm up and down.

  In step S2220, the memory value I indicating the vehicle height stored in the measurement vehicle height storage unit 132a allocated to the RAM 132 is initialized to zero. In step S2225, only the light emitter T specified in step S2215 emits light for one cycle. Also in the measurement measurement poles C and D, the upper light emitter T of the light emitter blocks P composed of the upper and lower light emitters T is caused to emit light first, and 4 ms later, The lower light emitter T emits light. Therefore, 8 ms is one cycle of light emission. In step S2230, the measured value M is specified from the light receiving state of each light receiver S.

  Since the method for specifying the measurement value M is the same as the detection value K described above, a description thereof will be omitted. The timing of light emission of the light emitter T at the measurement measurement poles C and D is determined when the memory value J output immediately after the rear end of the vehicle passes through the measurement measurement poles A and B is input to the measurement unit 130. Therefore, light emission can be started before the head of the vehicle 60 arrives at the measurement measurement poles C and D arranged downstream from the detection measurement poles A and B by a distance corresponding to the vehicle length. Therefore, the same vehicle 60 can be reliably measured again.

  As described above, in the measurement measurement poles C and D, the distance l between the light emitter T and the light receiver S adjacent to each other in the height direction is 2 cm. The vehicle height can be specified with four times the accuracy of the detected value K. That is, the measurement unit 130 can measure the vehicle height in units of 2 cm. The processes from step S2235 to S2250 are the same as steps S2140 to S2170 in the detection unit 120, and the process of updating and storing the highest vehicle height in the memory value I is performed. Accordingly, it is possible to store the highest vehicle height measured repeatedly in units of 2 cm as a memory value I after repeating light emission and measurement at a cycle of 8 ms. Note that the processes from step S2235 to S2250 are the same as steps S2140 to S2170 in the detection unit 120, and thus detailed description thereof is omitted.

  Similarly, in step S2250, it can be specified whether the vehicle is at the end of the vehicle. Here, if it is determined that it is the tail end, the output unit M137 performs processing for outputting the memory value I to the display 136 and the printer 138 in step S2255. Thereby, it is possible to notify the user of the final measurement result of the vehicle height. When output is performed in step S2255, light emission of the light emitter T disposed on the measurement measurement poles C and D is stopped in step S2260, and the input of the memory value J is awaited again in step S2205.

  By doing in this way, only the light-emitting device T required for measurement can be made to emit light only for a required period in the measurement measuring poles C and D. Therefore, power consumption can be reduced in the measurement measurement poles C and D. Further, as described above, since the light emitters T and the light receivers S are alternately arranged in the measurement measurement poles C and D, a highly reliable vehicle height measurement is performed even if the measurement is performed in the height direction. It is possible. Furthermore, since measurement can be repeated with a short cycle of 8 ms, even a vehicle traveling at high speed can be measured in the vehicle length direction. Since both the detection measurement poles A and B and the measurement measurement poles C and D can perform high-speed vehicle height measurement, the vehicle traffic is measured in order to measure the vehicle height throughout the vehicle height measurement device 110. There is no need to limit speed. Therefore, even if the vehicle height measuring device 110 is installed on a general road, the vehicle traffic is not hindered. The detection measuring poles A and B constitute temporary vehicle height measuring means in the present invention.

(4) Fourth embodiment:
FIG. 17 shows a hardware configuration of a vehicle height measuring apparatus according to the modification, and FIG. 18 shows a software configuration of the vehicle height measuring apparatus according to the modification. In FIG. 17, a vehicle speed measuring device 226 is connected to the bus 220a of the detection unit 220 via an I / F 227. The vehicle speed measuring device 226 detects that the vehicle has reached the detection measuring poles A and B, and measures the traveling speed of the vehicle. The vehicle speed measuring device 226 uses, for example, a device that detects a speed by irradiating a vehicle with a microwave and detecting a Doppler wave included in the reflected wave. Of course, you may use the apparatus which detects speed by another system. Since the vehicle speed can be measured instantaneously according to the microwave, the vehicle speed measurement can be completed while the vehicle passes through the detection measuring poles A and B.

  Also in FIG. 18, a module is added as a vehicle speed measuring unit M225 in order to detect the vehicle speed. The vehicle speed V acquired by the vehicle speed measuring unit M225 is stored in the vehicle speed storage unit 222b of the RAM 222. The vehicle speed V may be acquired while the vehicle passes the detection measuring poles A and B, and may be an average speed measured a plurality of times for the same vehicle. On the other hand, the light emission control unit M231 in the measurement unit 230 includes a prediction unit M231a. The prediction unit M231a is a module that predicts the timing for starting the light emitters T of the measurement measurement poles C and D from the vehicle speed V acquired by the reception unit M236. Since other configurations are the same as those in the previous embodiment, the description thereof is omitted.

  FIG. 19 shows the flow of detection processing in the detection unit 220. In the figure, in step S3180, the vehicle speed V measured while the vehicle passes the detection measurement poles A and B is output to the measurement unit 230 together with the memory value J indicating the maximum vehicle height of the vehicle. That is, the measurement unit 230 is notified of the maximum vehicle height and vehicle speed for the vehicle at the timing when the tail of the vehicle is detected. Since the vehicle speed V stored in the RAM 222 is initialized after the vehicle speed V is output, the vehicle speed V is not confused with the preceding and following vehicles.

  FIG. 20 shows the flow of measurement processing in the measurement unit 230. In the figure, input of the memory value J and the vehicle speed V is accepted in step S3210, and the activation time is predicted from the vehicle speed V in step S3218. In predicting the start-up time, first, based on the distance between the measurement measurement poles A and B and the measurement measurement poles C and D and the received vehicle speed V, the rear end of the vehicle determines the detection measurement poles A and B. The arrival time from the passage to the measurement poles C and D for measurement is calculated. The arrival time can be obtained by simply dividing the distance by the vehicle speed V.

  Based on this arrival time, the time for the head of the vehicle to reach the measurement measurement poles C and D is calculated as the activation time. For example, a certain time may be simply subtracted from the arrival time, or a time obtained by dividing the average vehicle length by the vehicle speed V may be subtracted. In any case, since there is a possibility that the vehicle speed may fluctuate, it is preferable to subtract the time with a margin. In step S3223, the light emission of the light emitter T is waited for the start time calculated as described above, and then the light emitter T is caused to emit light in step S3225.

  By doing in this way, the light emitters T of the measurement measuring poles C and D can emit light immediately before the head of the vehicle passes through the measurement measuring poles C and D. Accordingly, it is possible to reliably measure the target vehicle while not consuming unnecessary power. Also, since the start-up time can be predicted according to the distance between the detection measurement poles A and B and the measurement measurement poles C and D, the installation interval between the detection measurement poles A and B and the measurement measurement poles C and D is limited. Will never be done. Therefore, the measurement measurement poles A and B and the measurement measurement poles C and D can be installed according to the road conditions.

  When the installation intervals of the detection measurement poles A and B and the measurement measurement poles C and D are wide, a plurality of vehicles exist between the detection measurement poles A and B and the measurement measurement poles C and D. There is also a case. In this case, the memory value J and the vehicle speed V associated with each vehicle may be temporarily stored in a nonvolatile memory or the like, and sequentially read out and used. When it is desired to save more power, the timing at which the maximum vehicle height is detected at the detection measurement poles A and B is stored, and the measurement vehicle poles C and D have the highest vehicle height. It is also possible to predict the time when the vehicle reaches and measure only the vicinity of the portion where the vehicle height is highest.

  The above-described embodiment shows a preferable example, and the present invention is of course not limited to this embodiment. Therefore, the implementation can be carried out with any changes or modifications within the scope of the technical contents described in the claims.

(5) Summary:
In the present invention, first, it is possible to roughly specify where the vehicle height is by performing measurement with a wide measurement interval. Therefore, in the next measurement with a narrow interval, it is possible to measure only the specified height. Therefore, the vehicle height can be measured at a narrow measurement interval without causing the light emitters T of all heights to emit light. Since it is not necessary to cause the light emitters T of all heights to emit light, the time required for light emission of the light emitters T is shortened, and high-speed measurement is possible. In addition, power consumed by light emission from the light emitter T can be suppressed.

1 is an external perspective view of a vehicle height measuring device according to a first embodiment of the present invention. It is the figure which showed the arrangement | sequence state of the light emitter and light receiver concerning 1st embodiment. It is a hardware block diagram of the vehicle height measuring device concerning a first embodiment. It is a software block diagram of the vehicle height measuring device according to the first embodiment. It is a flowchart which shows the flow of the measurement process concerning 1st embodiment. It is a front view which shows a mode that vehicle height is measured in 1st embodiment. It is the figure which showed the arrangement | sequence state of the light emitter and light receiver concerning 2nd embodiment. It is a flowchart which shows the flow of the measurement process concerning 2nd embodiment. It is a front view which shows a mode that vehicle height is measured in 2nd embodiment. It is an external appearance perspective view of the vehicle height measuring apparatus concerning 3rd embodiment. It is the figure which showed the arrangement | sequence state of the light emitter and light receiver concerning 3rd embodiment. It is a hardware block diagram of the vehicle height measuring device concerning a third embodiment. It is a software block diagram of the vehicle height measuring apparatus concerning 3rd embodiment. It is a flowchart which shows the flow of the detection process concerning 3rd embodiment. It is a front view which shows a mode that vehicle height is measured in 3rd embodiment. It is a flowchart which shows the flow of the measurement process concerning 3rd embodiment. It is a hardware block diagram of the vehicle height measuring device concerning a 4th embodiment. It is a software block diagram of the vehicle height measuring apparatus concerning 4th embodiment. It is a flowchart which shows the flow of the detection process concerning 4th embodiment. It is a flowchart which shows the flow of the measurement process concerning 4th embodiment.

Explanation of symbols

10, 110, 210 ... Vehicle height measuring device 20 ... Control unit 120, 220 ... Detection unit 20a, 120a, 220a ... Bus 21, 121, 221 ... CPU
22a ... Vehicle height storage unit 122a, 222a ... Detection vehicle height storage unit 128, 228 ... Transmitter 130, 230 ... Measurement unit 20a, 130a, 230a ... Bus 21, 131, 231 ... CPU
132a, 232a ... Vehicle height storage units 26, 136, 236 ... Indicators 28, 138, 238 ... Printers 141, 241 ... Receivers 50 ... Vehicle passage 60 ... Vehicles A, B ... Measurement poles C for detection, D ... Measurement pole T for measurement ... Light emitter S ... Light receiver P ... Light emitter block Q ... Light receiver block

Claims (7)

A pair of measurement poles facing each other across the vehicle in the vehicle width direction, and a plurality of measurement heights in the measurement pole so that each light emitting part and light receiving part face each other between the pair of measurement poles And the light emitting control means for controlling the light emission of the detection light in the light emitter, and the light receiving state in each of the light receivers, so that the vehicle height is the highest position where the detection light is not received. In a vehicle height measuring device comprising: a vehicle height measuring means for specifying a height between the light receiver and the light receiving device at a lowest position where detection light is received;
A vehicle height measuring device characterized by repeatedly performing a wide measurement and a narrow measurement.   The two light emitters closest to each other in the height direction among the plurality of light emitters that emit light simultaneously by the light emission control means are disposed on the measurement poles different from each other. Vehicle height measuring device. The light emission control means includes
In the first measurement timing, the plurality of light emitters thinned in the height direction so that one or more light emitters that do not emit light exist in between, and emit light.
Thereafter, at the second measurement timing, the light emitter located between the highest position light receiver where the detection light is not received at the first measurement timing and the lowest position light receiver where the detection light is received. The vehicle height measuring device according to claim 2, wherein the vehicle height is emitted. The light emission control means includes
In the second measurement timing, the light emission at a predetermined position between the light receiving device at the highest position where the detection light is not received at the first measurement timing and the light receiving device at the lowest position where the detection light is received. Illuminate the device,
If no detection light is detected at the second measurement timing, the lowest position where the upper detection light is received at a position higher than the light emitter emitted at the second measurement timing and at the first measurement timing. The light emitter at a position lower than the light receiver at the position is caused to emit light at the third measurement timing,
When the detection light is detected at the second measurement timing, the highest position where the detection light is not received at the first measurement timing at a position lower than the light emitter emitted at the second measurement timing. The vehicle height measuring device according to claim 3, wherein the light emitting device at a position higher than the light receiving device at the position emits light at a third measurement timing. Temporary vehicle height measuring means for temporarily measuring the vehicle height upstream of the measurement pole in the traveling direction of the vehicle;
While equipped with vehicle height storage means for storing the vehicle height detected by the temporary vehicle height measurement means,
The light emission control means acquires the vehicle height stored in the vehicle height storage means, and causes only the light emitter having a height corresponding to the vehicle height to emit light in the measurement pole,
The vehicle height measuring device according to any one of claims 1 to 4, wherein the vehicle height measuring means specifies a vehicle height from a light receiving state of the light receiver facing the light emitter. Vehicle speed detection means for detecting the vehicle speed upstream of the measurement pole in the traveling direction of the vehicle;
A vehicle speed storage unit for storing the vehicle speed of the detected vehicle,
The light emission control means acquires the vehicle speed, predicts a time for the vehicle to reach the measurement pole from the vehicle speed, and starts light emission of the light emitter of the measurement pole at the predicted time. Item 6. The vehicle height measuring device according to Item 5.   The vehicle height measuring device according to any one of claims 1 to 6, further comprising output means for outputting the vehicle height specified by the vehicle height measuring means.

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