STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable to this application.

BACKGROUND

Field

Example embodiments in general relate to a vehicle flow monitoring system for detecting both a car count and direction of movement of vehicles passing a point of interest.

Related Art

Any discussion of the related art throughout the specification should in no way be considered as an admission that such related art is widely known or forms part of common general knowledge in the field.

Detecting and counting a vehicle as it passes a point for the purposes of determining parking lot usage, statistics or analysis has been around for some time, with traditional means of detection including ‘road tubes’, infra-red, magnetometer, image processing and inductive loops. ‘Road tubes’ are tubes installed on the road surface that trigger a change in pressure when an axle travels over the tube, which is then detected and counted. However, it only detects axles and therefore is difficult to distinguish between tail gating vehicles and trucks and similar such circumstances.

Inductive loops are impractical to install and are unreliable. They are often used for entry and exit points on parking lots and due to their unreliability, quickly lead to cumulative errors. Also, to determine the direction of a vehicle, two loops are required—doubling the impractical issues of installation.

Image processing is complicated and therefore prone to errors. Although the image sensor does not require mounting on the road surface, increasing the reliability, it is highly susceptible to difficult to control environmental conditions such as lighting.

Magnetometer based vehicle detection sensors typically measure disruptions in the earth's magnetic field caused by the presence of a vehicle. This disruption is small and unpredictable, as well as being temperature dependent—for these reasons, magnetometer based sensors have never achieved a high level of detection accuracy. These are also typically mounted on the road surface, which creates reliability issues due to the harsh environment.

Infra-red sensors rely heavily upon a clear or translucent window through an enclosure. This enclosure window is easily prone to damage rendering the sensor useless. When the window is blocked, either deliberately by misguided youths for example, or through environmental effects such as snow, the detection does not work. Furthermore, infrared sensors typically only have a binary output of present or not, limiting their practical use in algorithms.

SUMMARY

An example embodiment is directed to a vehicle flow monitoring system. The vehicle flow monitoring system includes a car counter which may include a microcontroller and a pair of distance sensors. Each of the distance sensors is oriented toward a unique point of interest. Each of the distance sensors includes a threshold distance reading which is used to detect whether a vehicle has passed underneath the car counter. The system may determine direction of travel of the vehicle based on which of the distance sensors is passed by the vehicle first. The microcontroller may assign an Event ID to each time a vehicle passes each of the sensors, with the Event ID being used to identify when and if the vehicle should be counted, or whether a non-vehicle object has passed the car counter.

There has thus been outlined, rather broadly, some of the embodiments of the vehicle flow monitoring system in order that the detailed description thereof may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional embodiments of the vehicle flow monitoring system that will be described hereinafter and that will form the subject matter of the claims appended hereto. In this respect, before explaining at least one embodiment of the vehicle flow monitoring system in detail, it is to be understood that the vehicle flow monitoring system is not limited in its application to the details of construction or to the arrangements of the components set forth in the following description or illustrated in the drawings. The vehicle flow monitoring system is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting.

