Communications: electrical – Traffic control indicator – Combined
Reexamination Certificate
1999-01-20
2001-02-27
Lefkowitz, Edward (Department: 2736)
Communications: electrical
Traffic control indicator
Combined
C340S933000, C340S937000, C235S384000, C356S370000, C356S398000, C701S117000
Reexamination Certificate
active
06195019
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a vehicle classifying apparatus for classifying a vehicle passing therethrough and a toll system including the same for requesting a toll in accordance the class.
2. Description of the Prior Art
A vehicle classifying apparatus for classifying the vehicle passing the sensor with the velocity and three dimensional profile determined with pulsed laser beam is known.
The vehicle classifying apparatus is provided to on a highway at a toll gate to automatically issue a note representing the class of the vehicle or the like. Moreover, in the automatically tolling system, the class (type) of the vehicle is detected. Such a vehicle classifying apparatus is disclosed in U.S. Pat. No 5,546,188.
FIG. 49
is a perspective view of such a prior art vehicle classifying apparatus. A vehicle classifying unit
10
is provided to a beam of gantry
13
for each lane at a highway toll gate. The vehicle classifying unit
10
confronts the lane
11
and emits laser beams Xa and Xb in width direction of the lane
11
with a predetermined interval to provide scanning lines La and Lb.
The laser beams Xa and Xb are emitted as pulses. Delay between the emitting timing and the receiving timing is detected to measure a distance. When an object having a height passes therethrough, the detected distance varies, so that the vehicle passing therethrough can be detected. The speed of the vehicle
14
is detected from the detected time interval that a portion of the vehicle
14
passing through a distance
5
. The length of the vehicle
14
is predicted from the detected time interval necessary for passage of the top to the end of the vehicle
14
and the detected speed.
SUMMARY OF THE INVENTION
The aim of the present invention is to provide an improved vehicle classifying apparatus and an improved toll system.
According to the present invention a first vehicle classifying apparatus is provided which comprises: a beam signal generation unit for generating a beam signal; a scanning unit, arranged at a predetermined position above a detection zone on a lane on which a vehicle to be classified travels, for emitting the beam signal with the beam signal scanned toward the detection zone along a scanning line inclined by a predetermined angle to a longitudinal direction of the lane; a receiving unit for receiving the beam signal reflected by the vehicle at the detection zone through the scanning unit; a distance detection circuit, including a memory, for detecting a delay time between the emission of the beam signal and reception of the beam signal, determining a distance between the scanning unit and the vehicle within the detection zone in accordance with the detected delay time, and outputting distance data indicative of the distance; and a classifying function responsive to the distance detection circuit for classifying the vehicle in accordance with the distance data and outputting the classified result.
In the first vehicle classifying apparatus, the predetermined angel may be zero. The first vehicle classifying apparatus may further includes: a characteristic point detection function for detecting characteristic points of an outline of the vehicle from the distance data; a correspondence detection function for detecting correspondence between previously detected first characteristic points and presently detected second characteristic points including a part of the first characteristic points; a characteristic point combining function for combining the first characteristic points with the second characteristic points in accordance with the detected correspondence.
In the first vehicle classifying apparatus, the angle may be an intermediate angle between the longitudinal direction and a width direction of the lane.
In the first vehicle classifying apparatus, the classifying function may detect a shape of an outline of the vehicle in the longitudinal direction.
The first vehicle classifying apparatus may further includes: a characteristic point detection function for detecting characteristic points of an outline of the vehicle from the distance data; a vehicle speed detection function responsive to the characteristic point detection function for detecting movement of the characteristic points, determining an instantaneous speed of the vehicle in accordance the detected movement, and outputting data of the instantaneous speed.
In this case, the vehicle speed variation detection function may detect a travelling speed of the vehicle within the detection zone in accordance with the detected movement.
Moreover, a vehicle speed variation detection function may be further provided which detects movement speed of the characteristic points, detects a variation of the travelling speed within the detection zone in accordance with the detected movement, and outputs data of the variation. In this case, the vehicle classifying function detects a shape of an outline of the vehicle in the longitudinal direction, the vehicle speed detection function detects an interval for which the movement of the characteristic points cannot be continuously detected; the vehicle classifying apparatus further comprising speed estimation function for estimating the travelling speed of the vehicle in accordance with the travelling speed and the variation detected before the interval and in accordance with the travelling speed and the variation after the interval.
Moreover, the classifying function may detect a shape of an outline of the vehicle in the longitudinal direction, the vehicle speed detection function detects an interval for which the movement of the characteristic point cannot be continuously detected, wherein the vehicle classifying apparatus may further include a speed estimation function for estimating the travelling speed of the vehicle in accordance with the travelling speed and the variation detected before the interval and in accordance with the travelling speed and the variation after the interval with assumption that the travelling speed varies successively.
The first vehicle classifying apparatus may further include an orthogonal component detection function for detecting characteristic points in a width direction perpendicular to the lane and width detection function for detecting a width of the vehicle from the detected characteristic points in the width direction.
The first vehicle classifying apparatus may further include, as second vehicle classifying apparatus; a second beam signal generation unit for generating a second beam signal; a second scanning unit, arranged at a second predetermined position above the detection zone on the lane, for emitting the second beam signal with the second beam signal scanned toward the detection zone along a second scanning line inclined to the longitudinal direction; a second receiving unit for receiving the second beam signal reflected by the vehicle through the second scanning unit; and a second distance detection circuit including a second memory for detecting a second delay time between a third timing when the second beam signal is emitted and a fourth timing when the second beam signal is received and determining a second distance between the second scanning unit and the vehicle in accordance with the detected second delay time and outputting second distance data indicative of the second distance, wherein the vehicle classifying function classifies the vehicle in accordance with the distance data and the second distance data.
In the second vehicle classifying apparatus, the direction of the second scanning line is different from the direction of the scanning line.
In the second vehicle classifying apparatus, the second scanning line may be perpendicular to the longitudinal direction.
In the second vehicle classifying apparatus, the second scanning line is perpendicular to the longitudinal direction and the predetermined angle may be zero. In this case, the vehicle classifying apparatus may further include a vehicle position judging function responsive to the second distance detection circuit for judging
Denso Corporation
Goins Davetta W.
Lefkowitz Edward
Pillsbury Madison & Sutro LLP
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