JP2002168678A - Vehicle weight detector and wheel width detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable easy measurements of the inter-wheel width of a vehicle. SOLUTION: An arrival time difference detector 4 detects the time difference in time between when a right wheel 11R of the vehicle 1 arrives at a weight detector 2, and the time when a left wheel 11L arrives at the detector 2, based on an electric signal output from the detector 2. A traveling speed measuring circuit 5 measures the speed of the vehicle 1, based on a time from the arrival of the wheels 11L and 11R of the vehicle 1 at a weight detector 21A, to the arrival at a weight detector 21C, based on the electrical signal output from the detectors 21A and 21C. An inter-vehicle width calculator 6 calculates the inter-wheel width of the vehicle 1, based on the time difference detected by the arrival time difference detector 4a and the speed measured by the circuit 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle weight detecting device and a vehicle width detecting device, and more particularly to, for example, a device for easily measuring a wheel interval width or a vehicle width of an axle of a running vehicle. The present invention relates to a vehicle weight detection device and a vehicle width detection device.

[0002]

2. Description of the Related Art Several methods have been proposed for measuring the weight of a running vehicle and the width of a wheel interval.

For example, Japanese Patent Laying-Open No. 11-148852 proposes a method of detecting the weight of a vehicle based on the detection results of a plurality of piezo sensors arranged in order in the traveling direction of the vehicle.

[0004] For example, Japanese Patent Application Laid-Open No. H10-111996
Japanese Patent Application Laid-Open No. 11-73592 and Japanese Unexamined Patent Application Publication No. 11-73592 disclose a large number of small weight detecting devices (for example, pressure-sensitive sensors) in a direction perpendicular to the traveling direction of the vehicle. When a wheel is detected, a method of measuring a wheel interval width from the distance between the weight detecting devices that have detected the wheel has been proposed.

Also, for example, JP-A-7-244794, JP-A-9-62982, and JP-A-10-32
In Japanese Patent Application Laid-Open No. 0687, Japanese Patent Application Laid-Open No. H11-313293, or Japanese Patent Application Laid-Open No. 2000-48297, a camera or a laser transmission / reception sensor is arranged above the lane and a gate is installed near the lane. There has been proposed a method of measuring a vehicle width by using a laser radar system or the like.

[0006]

However, the method disclosed in Japanese Patent Application Laid-Open No. H11-148852 has a problem that the weight of the vehicle can be detected but the width of the vehicle cannot be detected.

Further, in the method of measuring the wheel interval width of the vehicle disclosed in Japanese Patent Application Laid-Open Nos. 10-11196 and 11-73592, the vehicle width can be detected. However, there is a problem that it is necessary to lay a large number of small weight detecting devices, which results in an increase in the size of the device and an increase in cost.

Further, JP-A-7-244794,
JP-A-9-62982, JP-A-10-3268
No. 7, JP-A-11-313293, or JP-A-2000-48297, the method of measuring the vehicle width requires the provision of a gate post.
The vehicle cannot travel freely in the vicinity.
In addition, the vehicle width is measured while the cargo is loaded, and there is a problem that an error occurs in the measurement result due to the influence of the loaded cargo.

SUMMARY OF THE INVENTION The present invention has been made in view of such a situation, and it is an object of the present invention to measure a wheel interval width of a vehicle with high accuracy and easily.

[0010]

According to the present invention, there is provided a vehicle weight detecting device, wherein the first weight detecting means is laid obliquely to a traveling direction of the vehicle, and measures speed of the vehicle. Time difference measuring means for measuring a time difference between the time when the weight of the left wheel of the vehicle is detected and the time when the weight of the right wheel is detected by the first weight detecting means; a traveling speed measured by the speed measuring means; And a wheel interval width calculating means for calculating a width between the left wheel and the right wheel of the vehicle based on the time difference measured by the time difference measuring means.

In this vehicle weight detecting device, the left wheel of the vehicle and the right wheel of the vehicle are determined based on the traveling speed of the vehicle and the time difference between the time when the weight of the left wheel of the vehicle is detected and the time when the weight of the right wheel is detected. The width between the wheels is calculated. This allows
It is possible to easily measure the wheel interval width of the vehicle.

The first weight detecting means detects a weight applied from a wheel of a vehicle passing over the first weight detecting means laid on a road surface. For example, it is a linear sensor using a piezoelectric element, is laid obliquely on the road surface at an angle of α with respect to the traveling direction of the vehicle, and when the weight of the vehicle is detected, an electric power corresponding to the weight is detected. Output a signal.

The speed measuring means detects a traveling speed of the vehicle whose weight is detected. For example, it is a Doppler-type speed measurement sensor, which transmits a microwave beam to a running vehicle, receives a reflected wave from the vehicle, and, based on a frequency difference between transmitted and received waves, based on the principle of the Doppler effect. And measure the running speed of the vehicle.

The time difference measuring means determines, based on the electric signal output from the first weight detecting means, a time when the right wheel of the vehicle reaches the first weight detecting means and a time when the left wheel detects the first weight. The time difference between the times of arrival at the weight detection means is measured.

Depending on the angle of the laying angle of the first weight detecting means, the right wheel of the vehicle may reach the first weight detecting means first, or the left wheel of the vehicle may be moved to the first weight detecting means. Or reach the weight detection means first.

The wheel interval width calculating means includes: a traveling speed measured by the speed measuring means; a time when the right wheel of the vehicle reaches the first weight detecting means measured by the time difference measuring means; The width between the left wheel and the right wheel of the vehicle is calculated based on the time difference between the time when the left wheel reaches the first weight detecting means.

Here, the width between the left wheel and the right wheel of the vehicle is, for example, as shown in FIG. 5, the length from the center of the left wheel 11L to the center of the right wheel 11R. is there. This length is called the wheel interval width.

The first weight detecting means is, for example, as shown in FIG.
The speed measuring means comprises:
For example, the time difference measurement unit is configured by the speed measurement sensor 3 and the traveling speed measurement circuit 5 of FIG.
The wheel interval width calculating means is constituted by, for example, the arrival time difference detecting circuit 4 of FIG. 1 and the wheel interval width calculating circuit 6 of FIG.

The vehicle weight detecting device of the present invention may further include linear second and third weight detecting means for detecting the weight of the vehicle.

Therefore, the speed measuring means determines the time when the weight of the vehicle wheel is detected by the second weight detecting means,
The traveling speed of the vehicle may be calculated based on a time difference between times when the weights of the wheels of the vehicle are detected by the third weight detection unit.

The second and third weight detecting means are constituted by, for example, the weight detecting sections 21A and 21C shown in FIG.

A vehicle width detecting device according to the present invention comprises: first weight detecting means laid in a direction substantially perpendicular to the traveling direction of a vehicle and upstream of the traveling direction; Second weight detecting means laid in a direction substantially perpendicular to the vehicle and downstream of the traveling direction; third weight detecting means laid obliquely to the traveling direction of the vehicle; A time when the detection of the weight of the wheel of the vehicle is started by the detection means, a time when the weight of the wheel is detected by the first weight detection means, a time when the detection of the weight of the wheel is started by the second weight detection means, 3 based on the time when one of the left and right wheels starts to detect the weight of the left and right wheels and the time when the other weight of the left and right wheels ends detecting the other weight of the left and right wheels. Vehicle width calculating means for calculating a width between the vehicles as a vehicle width. It is characterized in.

In this vehicle width detecting device, the time when the first weight detecting means starts detecting the weight of the wheel, the time when the first weight detecting means finishes detecting the weight of the wheel, the second weight detecting means , The time when the weight of one of the left and right wheels is started to be detected by the third detecting means, and the time when the other weight of the left and right wheels is detected by the third detecting means. Based on the time, the width between the left and right wheels of the vehicle is calculated as the vehicle width. Thus, the width of the vehicle can be measured with high accuracy and easily.

The first weight detecting means detects a weight applied from a wheel of a vehicle passing over the first weight detecting means laid on a road surface. For example, it is a linear sensor using a piezoelectric element, is laid on the road surface in a direction substantially perpendicular to the traveling direction of the vehicle, and on the upstream side in the traveling direction, and when detecting the weight of the vehicle, An electric signal corresponding to the weight is output.

The second weight detecting means detects a weight applied from a wheel of a vehicle passing on the second weight detecting means laid on a road surface. For example, it is a linear sensor using a piezoelectric element, and is laid on the road surface in a direction substantially perpendicular to the traveling direction of the vehicle, and on the downstream side in the traveling direction, and when detecting the weight of the vehicle, An electric signal corresponding to the weight is output.

The third weight detecting means detects a weight applied from a wheel of a vehicle passing on the third weight detecting means laid on a road surface. For example, it is a linear sensor using a piezoelectric element, is laid obliquely on the road surface at an angle of α with respect to the traveling direction of the vehicle, and when the weight of the vehicle is detected, an electric power corresponding to the weight is detected. Output a signal.

The vehicle width calculating means includes a time when the first weight detecting means starts detecting the weight of the wheel, a time when the first weight detecting means finishes detecting the weight of the wheel, a second time detecting means. Time when the weight of the wheel started to be detected by the third
Between the left and right wheels of the vehicle based on the time when the weight of one of the left and right wheels has started to be detected by the detecting means and the time when the other weight of the right and left wheels has been detected by the third detecting means. Is calculated as the vehicle width.

Firstly, the rising time and falling time of the weight of the wheel is detected by the first weight detecting means, the pulse width T _P of the first weight detection means is calculated. next,
Based on the rising time at which the weight of the wheel is detected by the first weight detecting means and the rising time at which the weight of the wheel is detected by the second weight detecting means, the vehicle detects the first weight detecting means and the second weight detecting means. The time T _AC required to travel through the section of means is calculated. Next, based on the rising time when the weight of one wheel is detected by the third weight detecting means and the falling time when the weight of the other wheel is detected, a time T during which the vehicle 1 passes through the third weight detecting means is calculated. _B is calculated.

The vehicle width calculating means calculates the pulse width T.
_The vehicle width is calculated from _P , time T _AC , and time T _B according to the following equation. D is the distance between the first weight detecting means and the second weight detecting means. d _W = ((T _B −T _P ) · D ·) / T _AC

The vehicle width calculating means uses the time when the weight of the wheel has been detected by the second weight detecting means instead of the time when the weight of the wheel has been detected by the second weight detecting means. You may make it.

[0031] Therefore, the calculation of the pulse width T _P is the weight of the wheel may be employed by the fall time and the rise time is detected by the second weight detecting means. Further, the average of the pulse widths of the first weight detecting means and the second weight detecting means may be used.

The first weight detecting means is, for example, as shown in FIG.
The second weight detecting means is constituted by, for example, the weight detecting section 21C of FIG. 3, and the third weight detecting means is constituted by, for example, the weight detecting section 2B of FIG. The vehicle width calculating means is constituted, for example, by a wheel interval width calculating circuit 6 in FIG.

The vehicle width calculating means has started detecting the weight of one of the left and right wheels by the third detecting means, and has finished detecting the other weight of the right and left wheels by the third detecting means. Time when the weight of one of the left and right vehicles has been detected by the third detection means instead of the time; and
The time at which the third detecting means starts detecting the other weight of the left and right vehicles may be used.

The vehicle width detecting device of the present invention may further include a wheel width calculating means for calculating the width of the vehicle wheel.

For example, as shown in FIG. 11, a wheel width d is calculated from the width A of the weight detector 2 and the traveling speed v of the vehicle 1 according to the following equation. Note that t _BU2 is the time at which the third detection means starts detecting the weight of the vehicle,
t _BD2 is the time when the weight of the vehicle has been detected by the third detection means, and α is the angle at which the third detection means is laid obliquely to the traveling direction of the vehicle. d = v · (t _BD2 −t _BU2 ) − (A / sin α)

The vehicle width calculating means detects a rising time when the weight of one of the left and right wheels is detected by the third detecting means, and detects the other weight of the left and right wheels by the third detecting means. The vehicle width is calculated from the rising time. Then, the wheel width d calculated by the above equation is added to the calculated vehicle width.

As a result, an accurate vehicle width without errors can be calculated.

When the traveling direction of the vehicle is oblique with respect to the center line of the lane, the vehicle width detecting device according to the present invention has a time when the weight of the left wheel of the vehicle is detected by the first weight detecting means. The time difference between the time when the weight of the right wheel was detected, and
The vehicle width calculated by the vehicle width calculation means is calculated based on the total time of the time difference between the time when the weight of the left wheel of the vehicle is detected by the second weight detection means and the time when the weight of the right wheel is detected by the second weight detection means. Correction means for correcting may be further provided.

Thus, even if the traveling direction of the vehicle is deviated from the center line of the lane, the error can be easily corrected, so that the width between the left and right wheels of the vehicle can be accurately determined. Can be calculated as the vehicle width.

The correcting means is constituted by, for example, the wheel interval width calculating circuit 6 shown in FIG.

Further, the first weight detecting means and the second weight detecting means may be divided into left and right sides so that the weights of the left and right wheels of the vehicle can be respectively detected.

When the first weight detecting means is divided into left and right parts, for example, it is constituted by the weight detecting parts 21AL and 21AR shown in FIG. 11, and when the second weight detecting means is divided into right and left parts, for example, as shown in FIG. Weight detector 21CL, 21CR
It consists of.

With such a configuration, even when the vehicle travels obliquely with respect to the center line of the lane, the time when the right wheel reaches the weight detector 21AR and the time when the left wheel reaches the weight detector 21AL are reached. Time, right wheel is weight detector 21CR
And the left wheel is the weight detector 21CL
Can be individually measured, and the vehicle width can be calculated with high accuracy.

[0044]

FIG. 1 is a block diagram showing a configuration example of a first embodiment of a vehicle width detecting apparatus to which the present invention is applied.

The weight detection unit 2 is, for example, a linear pressure-sensitive sensor using a piezoelectric element, and has an angle α on the road surface with respect to the traveling direction of the vehicle 1 (rightward in FIG. 1). It is laid diagonally. When receiving the pressure from the left and right wheels 11L and 11R of the vehicle 1 (detecting the weight of the vehicle 1), the weight detector 2 outputs an electric signal instantaneously corresponding to the received pressure.

The speed measuring sensor 3 is, for example, a Doppler type speed measuring sensor, which transmits a microwave beam to the running vehicle 1, receives a reflected wave from the vehicle 1, and transmits and receives a reflected wave from the vehicle 1. Measure the frequency difference.

The arrival time difference detection circuit 4 detects the right wheel 1 of the vehicle 1 based on the electric signal output from the weight detection unit 2.
1R arrives at the weight detection unit 2 and the left wheel 11L.
Detects the time difference of the time when the vehicle arrives at the weight detection unit 2.

The traveling speed measuring circuit 5 includes a speed measuring sensor 3
The traveling speed of the vehicle 1 is measured based on the frequency difference between the transmitted and received waves measured in the above, based on the principle of the Doppler effect.

The wheel interval width calculating circuit 6 detects the time when the right wheel 11R of the vehicle 1 reaches the weight detecting section 2 and the time when the left wheel 11L reaches the weight detecting section 2 as detected by the arrival time difference detecting circuit 4. Based on the time difference between the times and the traveling speed of the vehicle 1 measured by the traveling speed measurement circuit 5, the wheel interval width of the axle 12 of the vehicle 1 (distance between the left wheel 11L and the right wheel 11R of the vehicle 1) Is calculated.

Next, referring to the flowchart of FIG.
The wheel interval width calculation process executed by the wheel interval width detecting device according to the first embodiment will be described.

In step S 1, the arrival time difference detection circuit 4 determines the time t _{R at} which the right wheel 11 R reaches the weight detection unit 2 based on the electric signal output from the weight detection unit 2.
And the time t _{L at} which the left wheel 11L reaches the weight detector 2.
, The time difference T _s (= t _L −t _R ) (sec) is detected. That is, the weight detection unit 2 is laid obliquely at an angle of α with respect to the traveling direction of the vehicle 1, and the right wheel 1
The time t _R when the first wheel 1R reaches the weight detector 2 and the left wheel 1
Since the time t _L at which 1L reaches the weight detection unit 2 is different,
The arrival time difference detection circuit 4 calculates the time difference T _S (= t _L −
t _R ).

In step S2, the traveling speed measurement circuit 5 measures the traveling speed v (m / sec) of the vehicle 1 from the frequency difference between the transmitted and received waves measured by the speed measurement sensor 3.

In step S3, the vehicle interval width calculating circuit 6 determines the time t _{R at} which the right wheel 11R of the vehicle 1 arrives at the weight detecting unit 2 and the weight of the left wheel 11L detected in step S1. Based on the time difference T _s of the time t _L at which the detection unit 2 is reached and the traveling speed v of the vehicle 1 measured in the process of step S2, the wheel interval width _dt is calculated according to the following equation (1). (The wheel width is different from the vehicle width, as will be described later with reference to FIG. 5). d _t = v · T _s · tanα (1)

Here, when the angle of the laying of the weight detector 2 with respect to the traveling direction of the vehicle 1 is α = 45 (degrees), the above equation (1) is expressed by the following equation (2). d _t = v · T _s (2)

As described above, the time t at which the right wheel 11R of the vehicle 1 arrives at the weight detector 2 laid diagonally on the road surface.
_R and the time t _{L at} which the left wheel 11L reaches the weight detector 2.
Time difference T _S, and, from the traveling speed v of the vehicle 1, with high precision, and it is possible to easily calculate the wheel spacing width d _t of the vehicle 1.

FIG. 3 is a block diagram showing a configuration example of a second embodiment of a vehicle width detecting apparatus to which the present invention is applied. In this configuration example, two linear weight detection units 21A and 21A are used instead of the speed measurement sensor 3 shown in FIG.
C is arranged. Other configurations are the same as those of the example shown in FIG. 1, and the description thereof will be appropriately omitted. Note that this configuration example is characterized by using three weight detectors, and for simplicity of description, the weight detector 2 shown in FIG. 1 will be referred to as a weight detector 2B. .

The weight detectors 21A and 21C, like the weight detector 2B (weight detector 2), are, for example, linear pressure-sensitive sensors using piezoelectric elements.
In a direction substantially perpendicular to the traveling direction of the vehicle (thus, substantially parallel to each other). Also, the weight detectors 21A and 21A
C is arranged at an installation distance D in the traveling direction of the vehicle 1. When the weight detectors 21A and 21C receive pressure from the left and right wheels 11L and 11R of the vehicle 1, they output instantaneous electrical signals corresponding to the received pressure.

The traveling speed measuring circuit 5 includes a weight detecting section 21A.
The left and right wheels 11L and 11R of the vehicle 1 are connected to the weight detector 21A based on the electric signals output from
Is detected until the vehicle reaches the weight detection unit 21C, and the traveling speed of the vehicle 1 is calculated based on the time and the installation interval D between the weight detection unit 21A and the weight detection unit 21C.

The wheel interval width calculating circuit 6 detects the time t _{R at} which the right wheel 11R of the vehicle 1 arrives at the weight detecting section 2B and the left wheel 11L detects the weight detecting section 2B. time difference T _S at time t _L has been reached, and, based on the traveling speed v of the vehicle 1 measured by the speed measuring circuit 5, and calculates the wheel spacing width of the axle 12 of the vehicle 1.

Next, referring to the flowchart of FIG.
A wheel width calculation process executed by the vehicle width detection device according to the second embodiment will be described.

In step S11, the arrival time difference detection circuit 4 determines the time t _{R at} which the right wheel 11R of the vehicle 1 reaches the weight detection unit 2B and the left time t _R based on the electric signal output from the weight detection unit 2B. detecting a time difference T _s of the time t _L of the wheels 11L reaches the weight detecting section _{2B (= t L -t R)} ( seconds).

In step S12, the traveling speed measurement circuit 5 determines the wheels 11L and 11R of the vehicle 1 based on the electric signals output from the weight detectors 21A and 21C.
There the time t ₁ that has reached the weight detecting unit 21A, the time T _D of the difference between the time t ₂ has been reached a weight detection unit 21C (= t ₂ -
t ₁ ) (seconds) is measured.

[0063] speed measuring circuit 5, as shown in the following equation (3), the distance D of the weight detecting section 21A and 21C, by dividing the time T _D obtained as described above, the vehicle 1 The running speed v is obtained. _{v = D / T D ··· (} 3)

In step S13, the vehicle interval width calculation circuit 6 determines whether the vehicle 1 has been detected in the processing in step S11.
T when the right wheel 11R of the vehicle reaches the weight detection unit 2
_R and the time t _{L at} which the left wheel 11L reaches the weight detector 2.
The wheel interval width d _t is calculated according to the following equation (4) based on the time difference T _{s of} the vehicle and the traveling speed v of the vehicle 1 measured in the processing of step S12. d _t = v · T _s · tanα (4)

The obtained equation (4) is consequently expressed as
It can be seen that the above equation (1) described in the first embodiment is the same. Therefore, when the angle of the laying of the weight detector 2B with respect to the traveling direction of the vehicle 1 is α = 45 (degrees), the above equation (4) is expressed by the above equation (2).

[0066] Thus, the time t _R of the right wheel 11R of the vehicle 1 reaches the weight detection unit 2B laid obliquely on the road surface, the time t _L of the left wheel 11L reaches the weight detecting section 2B , And the wheels 11L, 11R of the vehicle 1
Based on the time from when the vehicle arrives at the weight detecting unit 21A to when the vehicle arrives at the weight detecting unit 21C, it is possible to calculate the wheel interval width of the vehicle as the vehicle width with high accuracy and easily.

Incidentally, the wheel interval width does not exactly match the vehicle width. That is, as shown in FIG. 5, the wheel interval width is a length from the center of the wheel 11L mounted on the axle 12 to the center of the wheel 11R, and the vehicle width is based on the width of the wheel. It is the length from the left end of the wheel 11L to the right end of the wheel 11R.

When measuring the vehicle width (rather than the wheel interval width), as shown in FIG. 6, after the outer portion of the right wheel 11R of the vehicle 1 reaches the weight detector 2B, the left wheel 11
Time T _w until the outer portion of L reaches weight detector 2B
Need to be measured. However, according to the above-described method, as shown in FIG. 7, after the outer portion of the right wheel 11R of the vehicle 1 reaches the weight detector 2B, the inner portion of the left wheel 11L actually detects the weight. The time T _W ′ until reaching the unit 2B is measured. Therefore, as shown in FIG. 8, the time _Tw is calculated using a plurality of timing differences.

[0069] Before describing the principle of calculating the time T _w in Fig. 8 and 9, the wheel 11L, 1 at each time
1R, a weight detector 2B, a weight detector 21A, and 2
A description will be given of the relationship between the relative position and 1C. here,
In addition to the width of the wheels 11L and 11R, the weight detectors 2B and 21
The width of A, 21C is also considered.

As shown in FIG. 9 (A), the time at which the left and right wheels 11L and 11R reach the weight detector 21A is defined as time t _AU .

[0071] As shown in FIG. 9 (B), the left and right wheels 11L and 11R are the time t _AD time which has passed through the weight detection unit 21A.

As shown in FIG. 9C, the right wheel 1
The time when 1R reaches the weight detection unit 2B is _defined as time t _BU1 .

As shown in FIG. 9D, the right wheel 1
The time when 1R passes through the weight detection unit 2B is _defined as time _tBD1 .

As shown in FIG. 9E, the left wheel 1
The time when 1L reaches the weight detection unit 2B is time _tBU2 .

As shown in FIG. 9 (F), the left wheel 1
The time at which 1L passes through the weight detection unit 2B is _defined as time t _BD2 .

As shown in FIG. 9 (G), the time at which the left and right wheels 11L and 11R reach the weight detector 21C is defined as time _tCU .

As shown in FIG. 9 (H), the time at which the left and right wheels 11L and 11R pass through the weight detector 21C is defined as time t _CD .

Referring back to FIG. 8, the weight detectors 21A and 21A
The average T _P of the length of the period in which the wheel 1C is detecting the wheel 11 (the pulse width output during the detection period) is expressed by the following equation (5) using each time shown in FIG. T _P = ((t _AD −t _AU ) + (t _CD −t _CU )) / 2 (5)

When it is not necessary to take the average of t _AD −t _AU and t _CD −t _CU , the above equation (5) is expressed by the following equation (6). The value obtained from any of the expressions (6) may be used. T _P = t _AD −t _AU = t _CD −t _CU (6)

The time T _B from when the right wheel 11R reaches the weight detector 2B to when the left wheel 11L passes through the weight detector 2B is expressed by the following equation (7). _{T B = t BD2 -t BU1 ···} (7)

Further, the time T _AC required for the axle 12 of the vehicle 1 to travel in the section D between the weight detector 21A and the weight detector 21C is expressed by the following equation (8). Any of the expressions (8) may be used. T _AC = t _CU -t _AU = t _CD -t _AD (8)

Here, with reference to the timing chart of FIG. 10, the pulses output by the weight detector 2B and the weight detectors 21A and 21C during the detection period of the wheel 1 will be described.

[0083] The weight detection unit 21A receives the pressure by the wheels 11L and 11R of the left and right of the vehicle 1 passes, in response to the received pressure, the time t _AU to the time t _AD
Time, outputs a pulse P ₁ (FIG. 10 (A)).

The weight detector 2B is connected to the right wheel 11 of the vehicle 1.
When subjected to pressure by R passes, in response to the received pressure, the time of time t _BU1 to the time t _BD1, and outputs a pulse P ₂ (FIG. 10 (B)).

The weight detecting section 2B is connected to the left wheel 11 of the vehicle 1.
When subjected to pressure by L passes, in response to the received pressure, the time of time t _BU2 to the time t _BD2, and outputs a pulse P ₃ (FIG. 10 (B)).

When the weight detector 21C receives the pressure due to the passage of the left and right wheels 11L and 11R of the vehicle 1, the weight detector 21C responds to the received pressure by the time t _{CU to the} time t _CD.
Time, and outputs a pulse P ₄ (FIG. 10 (C)).

As shown in FIG. 8, the time T _P ′ from when the outer portion of the left wheel 11L reaches the weight detector 2B until it separates can be approximated to the time T _P. At this time, the time T _W
Can be calculated according to the following equation (9). T _W = T _B −T _P ′ = T _B −T _P (9)

[0088] The above pulse width T _P, the right wheel of the vehicle 1 1
The time T _W from when the outer portion of 1R reaches the weight detector 2B to when the outer portion of the left wheel 11L reaches the weight detector 2B, and when the axle 12 of the vehicle 1 detects the weight with the weight detector 21A. Time T required to travel in section D of section 21C
_{From AC} , the vehicle width d _W is obtained by the following equation (10). d _W = (T _W · D · tan α) / T _AC = ((T _B -T _P ) · D · tan α) / T _AC (10)

Here, when the angle of the laying of the weight detector 2B with respect to the traveling direction of the vehicle 1 is α = 45 (degrees), the above equation (10) is expressed by the following equation (11). d _W = ((T _B −T _P ) · D) / T _AC (11)

As described above, the vehicle width including the widths of the wheels 11L and 11R of the vehicle 1 can be easily calculated by using a plurality of timing differences as described with reference to FIG.

Here, an error due to the fact that the width of the weight detecting section 2B is not 0 will be estimated. For example, the weight detector 2B
Is 5 (cm) and the angle of laying of the weight detection unit 2B with respect to the traveling direction of the vehicle 1 is α = 45 (degrees), then 5 · (√2-1) ≒ 2 (cm).

By the way, in the above-described example using a plurality of timing differences, the outside of the left wheel 11L is
The time T _P ′ from when the vehicle reaches B to the time when the vehicle leaves the vehicle B is determined by the time T _P during which the weight detectors 21A and 21C detect the wheel 11.
_{Although the} vehicle width was calculated as an approximation to _P , the present invention is not limited to this, and the width of the wheel 11 is calculated from the width of the weight detection unit 2 and the traveling speed of the vehicle 1, and the width of the wheel 11 is used. Thus, the vehicle width can be calculated without error.

Therefore, referring to FIG.
An example in which the width of the wheel 11 is calculated from the width of the vehicle 1 and the traveling speed of the vehicle 1 and the width of the wheel 11 is calculated without error using the width of the wheel 11 will be described. As shown in the figure, A represents the width of the weight detector 2, and d represents the width of the wheel 11-L (or the wheel 11-R).

The distance from when the inner part of the left wheel 11L reaches the weight detector 2 to when it separates is A / sin α,
The distance from the inner part of the left wheel 11L to the weight detector 2 to the outer part of the left wheel 11L to the weight detector 2 is d / tanα. Using these values, the distance from when the left wheel 11L reaches the weight detection unit 2 to when the left wheel 11L separates is determined by the following equation (12).
The time t _BU2 when L reaches the weight detection unit 2 and the left wheel 1
The travel speed V of the vehicle 1 can be obtained by dividing by the time difference from the time t _{BD2 when} 1L passes through the weight detection unit 2. v = ((A / sin α) + (d / tan α)) / (t _BD2 −t _BU2 ) (12)

When the above equation (12) is expanded for the width d of the wheel 11, it is expressed by the following equation (13). d = (v · (t _BD2 −t _BU2 ) − (A / sin α)) tan α (13)

Here, when the angle of the laying of the weight detector 2 with respect to the traveling direction of the vehicle 1 is α = 45 (degrees), the above equation (13) is expressed by the following equation (14). d = v · (t _BD2 −t _BU2 ) − (A / sinα) (14)

By adding the obtained width d of the wheel 11 to the wheel interval width dt calculated by the above-described method, an accurate vehicle width without errors can be calculated.

In the above, the left and right wheels 11 of the vehicle 1
The description has been made assuming that L and 11R arrive at the weight detection unit 21A or 21C at the same time. However, FIG.
As shown by a dotted line, the vehicle 1 sometimes runs obliquely with respect to the center line of the lane (the direction perpendicular to the weight detectors 21A and 21C). That is, the wheels 11L and 11R of the vehicle 1 may not arrive at the weight detectors 21A or 21C at the same time, but may arrive slightly shifted. Therefore, next, a method of correcting an error in the traveling direction of the vehicle 1 will be described.

In the configuration example of FIG. 12, the weight detecting means 21A and 21C shown in FIG. 3 can detect the pressures of the left and right wheels 11L and 11R individually.
Each is divided into two. That is, instead of the weight detector 21A shown in FIG.
And 21AR, and weight detectors 21CL and 21CR are provided instead of the weight detector 21C.

Here, with reference to the timing chart of FIG. 13, the weight detector 2B and the weight detector 21A
The pulses output by L, 21AR, 21CL, and 21CR when detecting the wheels of vehicle 1 will be described.

Assuming that the vehicle 1 is traveling leftward from the center line of the lane, the weight detector 21A
R receives the pressure due to the passage of the right wheel 11R of the vehicle 1, and the time t _AUR corresponds to the received pressure.
From time t _ADR to pulse P ₁₂ (FIG. 13
(B)).

[0102] The weight detection unit 21AL receives the pressure by the left wheel 11L of the vehicle 1 passes, in response to the received pressure, the time of time t _AUL to the time t _ADL, outputs a pulse P ₁₁ (FIG. 13A).

[0103] The weight detecting section 2B is connected to the right wheel 11 of the vehicle 1.
When subjected to pressure by R passes, in response to the received pressure, the time of time t _BU1 to the time t _BD1, and outputs a pulse P ₁₃ (FIG. 13 (C)).

[0104] The weight detecting section 2B is provided with the left wheel 11 of the vehicle 1.
When subjected to pressure by L passes, in response to the received pressure, the time of time t _BU2 to the time t _BD2, and outputs a pulse P ₁₄ (FIG. 13 (C)).

[0105] The weight detection unit 21CR receives the pressure by the right wheel 11R of the vehicle 1 passes, in response to the received pressure, the time of time t _CUR to the time t _CDR, outputs a pulse P ₁₆ (FIG. 13E).

[0106] The weight detection unit 21CL receives the pressure by the left wheel 11L of the vehicle 1 passes, in response to the received pressure, the time of time t _CUL to the time t _CDL, outputs a pulse P ₁₅ (FIG. 13D).

From the above, the weight detectors 21AL, 2
Average T of pulse width of 1AR, 21CL, and 21CR
_P is represented by the following equation (15). T _P = ((t _ADL −t _AUL ) + (t _ADR −t _AUR ) + (t _CDL −t _CUL ) + (t _CDR −t _CUR )) / 4 (15)

After the right wheel 11R of the vehicle 1 reaches the weight detecting section 2B, the left wheel 11L is moved to the weight detecting section 2B.
The time T _B before passing through _B is expressed by the following equation (16). _{T B = t BD2 -t BU1 ···} (16)

Further, the axle 12 of the vehicle 1 is
The time T _AC required to travel in the section D between the AL and the weight detector 21CL is represented by the following equation (17). Equation (17)
May be used from any of the equations. T _AC = t _CUL -t _AUL = t _CUR -t _AUR (17)

Further, the time difference between the time when the left wheel 11L reaches the weight detecting unit 21AL and the time when the right wheel 11R reaches the weight detecting unit 21AR, and
The time when 1L reaches the weight detector 21CL and the right wheel 1
The total _TG of the time difference between the times when 1R reaches the weight detection unit 21CR is expressed by the following equation (18). _TG = (t _AUL −t _AUR ) + (t _CUL −t _CUR ) (18)

Here, when T _G ≪T _AC , the vehicle width d _w is expressed by the following equation (19). _{d W = ((T B -T} P + T G) · D · tanα) / T AC ··· (19)

The weight detector 2 for the center line of the lane
When the laying angle of B is α = 45 (degrees), the above equation (1)
9) is represented by the following equation (20). d _W = ((T _B −T _P + T _G ) · D) / T _AC (20)

When v = D / T _AC is substituted, the above equation (20) is expressed by the following equation (21). _{d W = (T B -T P} + T G) · v ··· (21)

Further, when the inclination of the laying of the rectangular weight detecting portion 2B is made opposite to the direction shown in FIG.
The above equations (20) and (21) are represented by the following equation (22). d _W = ((T _B -T _P -T _G ) ＴD) / T _AC = (T _B -T _P -T _G ) ・ v (22)

As described above, even when the traveling direction of the vehicle 1 is deviated from the center line of the lane, the error can be easily corrected, and the left and right wheels 11L and 11R of the vehicle 1 can be corrected. The vehicle width including the width can be calculated with high accuracy.

FIG. 14 shows a summary of the method for correcting the error in the traveling direction of the vehicle 1 described above.

As shown in the figure, when the traveling direction of the vehicle 1 is normal, that is, when the traveling direction is the same as the center line of the lane, the outside of the right wheel 11R of the vehicle 1 is connected to the weight detecting section 2B.
Is reached, the outer portion of the left wheel 11L is the weight detector 2
The time T _w to reach the _{B, T W = T B -T} P , and when the traveling direction of the vehicle 1 is shake left, time T
_W becomes T _W = T _B -T _P + T _G , and when the traveling direction of the vehicle 1 is right-handed, the time T
_W is given by T _W = T _B -T _P -T _G.

However, the weight detector 2B shown in FIG.
When the traveling direction of the vehicle 1 deviates to the left when the inclination of the laying of the vehicle is reversed, the time T _W becomes T _W = T _B −T _P −T
_G , and when the traveling direction of the vehicle 1 deviates rightward, T _W = T _B
The -T _P + T _G.

[0119]

According to the vehicle weight detecting device and the vehicle width detecting device of the present invention, the wheel interval width and the vehicle width of the vehicle can be measured.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a first embodiment of a vehicle width detection device to which the present invention has been applied.

FIG. 2 is a flowchart illustrating a wheel interval width calculating process of the vehicle width detecting device of FIG. 1;

FIG. 3 is a block diagram illustrating a configuration example of a second embodiment of a vehicle width detection device to which the present invention has been applied.

FIG. 4 is a flowchart illustrating a wheel interval width calculating process of the vehicle width detecting device of FIG. 3;

FIG. 5 is a diagram illustrating definitions of a wheel interval width and a vehicle width.

FIG. 6 is a diagram illustrating timings required when measuring a vehicle width.

FIG. 7 is a diagram illustrating timings actually measured when measuring a vehicle width.

FIG. 8 is a diagram illustrating a plurality of timing differences required when calculating a vehicle width.

FIG. 9 is a diagram illustrating a relationship between relative positions of a wheel and a weight detection unit at each time.

FIG. 10 is a timing chart of pulses output by the weight detection unit in FIG. 9 when a wheel is detected.

FIG. 11 is a diagram illustrating a method of calculating a wheel width.

FIG. 12 is a diagram illustrating a method for correcting an error in the traveling direction of a vehicle.

FIG. 13 is a timing chart of a pulse output by the weight detection unit in FIG. 12 when a wheel is detected.

FIG. 14 is a diagram illustrating a method for correcting an error in the traveling direction of the vehicle.

[Explanation of symbols]

 Reference Signs List 1 vehicle 2 weight detection unit 3 speed measurement sensor 4 arrival time difference detection circuit 5 traveling speed measurement circuit 6 wheel interval width calculation circuit 11L, 11R wheels 12 axle 21A, 21C weight detection unit

Claims (8)

[Claims] 1. A vehicle weight detection device for detecting the weight of a vehicle traveling on a road surface by a first linear weight detection unit laid on the road surface, wherein the first weight detection unit is a vehicle. A speed measuring means for measuring a traveling speed of the vehicle, a time at which the weight of the left wheel of the vehicle is detected by the first weight detecting means, and a weight of the right wheel. The time difference measuring means for measuring the time difference of the detected time, The traveling speed measured by the speed measuring means, and the left wheel of the vehicle based on the time difference measured by the time difference measuring means A wheel interval width calculating means for calculating a width between the right wheels. 2. A linear second vehicle for detecting a weight of the vehicle.
And third weight detecting means, wherein the second and third weight detecting means are laid in a direction substantially perpendicular to the traveling direction of the vehicle, and wherein the speed measuring means is provided with the second weight. Measuring the traveling speed of the vehicle based on a time difference between a time when the weight of the vehicle wheel is detected by the detection means and a time when the weight of the wheel of the vehicle is detected by the third weight detection means. The vehicle weight detecting device according to claim 1, wherein: 3. A vehicle width detecting device for detecting a vehicle width of a vehicle traveling on a road surface, wherein the vehicle width detecting device is in a direction substantially perpendicular to a traveling direction of the vehicle, and
First weight detection means laid on the upstream side in the traveling direction, in a direction substantially perpendicular to the traveling direction of the vehicle, and
A second weight detecting means laid on the downstream side in the traveling direction; a third weight detecting means laid obliquely to the traveling direction of the vehicle; A time at which the weight of the wheel is started to be detected, a time at which the weight of the wheel is completely detected by the first weight detecting means, a time at which the weight of the wheel is started to be detected by the second weight detecting means, 3 based on the time when one of the left and right wheels starts detecting the weight of the left and right wheels by the detecting means, and the time when the other weight of the left and right wheels ends detecting by the third detecting means. A vehicle width calculating means for calculating a width between left and right wheels as a vehicle width. 4. The vehicle width calculating means finishes detecting the weight of the wheel by the second weight detecting means instead of the time when the weight of the wheel is started to be detected by the second weight detecting means. The vehicle width detecting device according to claim 3, wherein the time is used. 5. The vehicle width calculating means includes a time when the third detecting means starts detecting the weight of one of the left and right wheels, and a time when the third detecting means detects the other of the right and left wheels. Instead of the time when the weight has been detected, the time when one of the left and right vehicles has been detected by the third detecting means, and the other weight of the left and right vehicles by the third detecting means. 4. The vehicle width detecting device according to claim 3, wherein a time at which detection of the vehicle width is started is used. 6. A wheel width calculating means for calculating a wheel width of the vehicle, wherein the vehicle width calculating means starts detecting the weight of one of the left and right wheels by the third detecting means. And calculating the vehicle width based on the time when the third detecting means starts detecting the other weight of the left and right wheels, and calculating the calculated vehicle width by the wheel width calculating means. 6. The vehicle width detecting device according to claim 3, wherein the determined wheel widths are added. 7. When the traveling direction of the vehicle is oblique to the center line of the lane, the time when the weight of the left wheel of the vehicle is detected by the first weight detecting means and the time of the right wheel Based on the time difference between the time when the weight is detected and the total time difference between the time when the weight of the left wheel of the vehicle is detected by the second weight detecting means and the time when the weight of the right wheel is detected by the second weight detecting means. 7. The vehicle width detecting device according to claim 3, further comprising a correcting unit that corrects the vehicle width calculated by the vehicle width calculating unit. 8. The apparatus according to claim 1, wherein said first weight detecting means and said second weight detecting means are respectively divided into left and right so that the weights of left and right wheels of said vehicle can be respectively detected. 8. The vehicle width detecting device according to 7.