JPS6043000B2 - Time occupancy measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a device for measuring the time occupancy rate of a vehicle based on the output time width of a vehicle detector.

(b) Prior Art and Its Disadvantages Conventionally, ultrasonic detectors and loop detectors have been used to measure vehicle occupancy, which is useful for traffic control.

However, in the conventional technology, there is a large error in measuring the time occupancy rate, or it is easy to malfunction due to noise. That is, based on FIG. 1, the principle of measuring the occupancy rate according to the present invention or the prior art will be explained. 1 is a vehicle and its length is S'.

2 is a loop type vehicle detector, and the length of its detection range is l.

Now, when vehicle 1 passes over detector 2, detector 2
A detection output is output for a period of time corresponding to S'+l from when the front end of the vehicle 1 enters the detection range until the rear end of the vehicle 1 exits. It is obvious that the time corresponding to S'+l is longer than the actual vehicle time occupancy rate. Conventionally, such an error has been ignored, assuming that the detection width l is sufficiently small relative to the vehicle length S'. Although this is certainly acceptable to some extent for trucks with long lengths,
'For vehicles with short vehicle lengths, such as small passenger cars, the influence of the detection width l becomes large, and the measurement accuracy of conventional methods deteriorates. Furthermore, in the conventional technology as described above, since the detection width l is set short, it is sensitive to relatively small objects and is susceptible to noise. (c) Purpose The present invention was made in view of the drawbacks of the prior art, and an object of the present invention is to more accurately measure the time occupancy rate of vehicles.

(d) Configuration and effect In the present invention, the time width Op of the detection output of the vehicle detector
However, the time occupancy rate is measured based on the integrated value of s, l, and 2 (where S is the average vehicle length and l is the length of the detection range of the vehicle detector). It has the following effects on things:

Note that the average vehicle length S is a representative value of the vehicle group statistically determined by previously investigating the vehicle group passing through the corresponding road where the detector is installed. 1. The measurement accuracy is improved because the influence of the length of the detection range of the vehicle detector is removed.

Since the influence of the vehicle speed of passing vehicles is also corrected, measurement accuracy is improved.

3.Since the effect of the length of the detection range can be removed, there is no need to set the detection range short like in the past, and it can be set long. This makes it possible to perform stable measurements that are resistant to noise and are not sensitive to small objects.

4. Since the time occupancy rate is measured based on the integrated value, even if the measurements based on the average vehicle length vary individually, accurate measurements can be made as a whole.

(e) Examples An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram showing an end circuit for correcting the actually measured occupancy time and obtaining an accurate time occupancy rate.

The output of the vehicle detector 4 is input to an AND circuit 5 together with the pulse output of the oscillator A, and the output of the AND circuit 5 is input to a counter 6. The output 0p of the counter 6 serves as one input of a multiplication circuit 7, which is an example of calculation means, and the output of the setting section 8 is given as the other input of the multiplication circuit 7. The output 0 of the multiplier circuit 7 is input to the memory 9.
On the other hand, the pulse output of the oscillator B is given to the time signal generator 10, and the output of the time signal oscillator 10 is input to the timing control section 11. The output of the vehicle detector 4 is given as the other input of the timing control section 11 . From the timing control section 11, a reset signal 12 is applied to the counter 6, a read signal -13 is applied to the multiplication circuit 7, and a read signal 14- and a read signal 15 are applied to the memory 9. It is assumed that the output of the memory 9 is sent to the central processing unit CPU every time the read output 15 is output. - Now, when a vehicle (not shown) arrives at the detection loop (not shown) of the vehicle detector 4, the detector 4 outputs the detection signal shown in FIG. 1b.

The AND circuit 5 is activated while the detection signal is "1", and the pulse output of the oscillator A passes through the AND circuit 5 to the counter 6.
is input. The counter 6 continues to advance in response to the pulse output from the oscillator A, and stops advancing when the detection signal reaches "0".

Based on the detection output of the detector 4, the timing control section 11 provides a read signal 13 to the multiplication circuit 7 at the falling timing of the detection output, and inputs the count value output 0P of the counter 6 to the multiplication circuit 7. In response to the input of this read signal 13, the set value of the setting section 8 is also input to the multiplier circuit 7. Then count s+
E6 is the reset signal 12 from the timing control section 11
It is reset by .

The multiplier circuit 7 has the output 0p from the counter 6 and the setting section 8.
The multiplication result of the multiplication circuit 7 is inputted to the memory 9 as an output 0s by the read signal 14 sent from the timing control s+e control section 11 to the memory 9 after a predetermined time.

Thereafter, each time a vehicle enters the detection loop, the actual measured value of the occupancy time is given as the output value 0p of the counter 6, and the value obtained by multiplying this value by the set value 0p of the setting section 8 is input into the memory 9.

Every time the multiplication result from the multiplier circuit 7 is given to the memory 9 as an output value 05, the value is integrated in the memory 9, and the timing controller 11 outputs the value to the memory 9 at predetermined intervals.
The integrated value is read out by the readout signal 15 issued to
It is sent to the central processing unit CPU. The read signal 15 is
Based on the pulse output of the oscillator B, the time signal generator 10 outputs a time signal (usually at 5 minute intervals) every time the time signal is input to the timing control section 11. The CPU measures the time occupancy rate by dividing the integrated value sent from the memory 9 by the period of the sending cycle. In this embodiment, the memory 9 is provided with the integration function, but the integration may be performed by the CPU.

Furthermore, the integrated value of the occupied time may be divided by the period of the sending cycle of the read signal 15 to obtain the time occupied rate at the end, and then sent to the CPU.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the case where the presence of a vehicle is detected by a loop type detector, and FIG. 2 is a block diagram of an uncircumscribed circuit for correcting vehicle occupancy time and obtaining an accurate time occupancy rate. 4...Vehicle detector, 6...Counter, 7
...Multiplication circuit, 8...Setting section, 9...
...Memory, 11...Timing control section.

Claims (1)

[Claims] 1. In a device that measures the time occupancy rate based on the detection output time of a vehicle detector, the vehicle detector has a predetermined detection range l with respect to the traveling direction of the vehicle, and the time width Op of the detection output of this vehicle detector. a vehicle occupancy time detector for detecting the vehicle occupancy time; a set value means for setting the length l of the detection range and the average vehicle length S of the passing vehicle group; and the time width Op which is the output of the vehicle occupancy time detector. has a correction value calculating means for calculating a correction value obtained by multiplying the correction value by S/S+l, and an integrating means for calculating an integrated value of the correction value, and measures the time occupied flow based on the output of the integrating means. A device for measuring the time occupancy rate.