Traffic sensor

The government of the United States is currently active

Study the "intelligent freeway" to improve

The construction of a new highway. Leading thought

Think if it's true to the existing freeway

Now electronic management can be more satisfied

The flow density of the car.

In addition to conventional traffic monitoring for Highway Research and law enforcement, intelligent vehicle / expressway system

(IVHS) the plan is required for the new grade "intelligent expressway" high-speed detector, counting the vehicles,

Classification, provide lane control, to control the weight and speed. IVHS also needs "smart car" sensors, advanced vehicle surveillance, communications, and software systems.

Future plans like IVHS and

More like "strategic highway research"

A modern item such as SHRP.

All of them need to collect traffic data and go to the United States

The federal highway department is required to provide

The information needed for the construction of the freeway. near

The progress of signal processing has opened in the past year

The improvement of real-time vehicle data analysis

The door, but the premise is to develop a low cost

Depending on the sensor technology.

Road pneumatic pipe has long been the main force of traffic data collection. It provides pneumatic pulse for piezoelectric thin film, and triggers nearby electronic devices when axle passes.

Evaluation of various sensor technologies shows that piezoelectric membrane cables can provide sensitivity, linearity, noise immunity and environmental stability for highway interstate vehicle classification and running weighing system. The piezoelectric film cable BL sensor is used in the traffic data acquisition system in Saskatchewan, Canada, to Florida, USA.

The structure of a piezoelectric cable traffic sensor is shown in FIGS. 54 and 55. It is mainly divided into two kinds of permanent and temporary. In a word, it is permanently installed in the middle of the road to make the top of the sensor flat and the road surface, while the temporary is stuck on the road for short-term monitoring. Permanent sensors are applied to the toll station and the interstate data acquisition, installation and the road must be flush, high density traffic, withstand the snow vehicles, year after year, salt water, sand cover and cleaning.

"The New Jersey wall", this modern

The cement isolating wall will turn the road in the opposite direction

The driveway is separated, and this produces four lanes

Multi Lane sensing of freeway. pressure

Electric cable uses a sensor for each phase

The way the driveway has the opposite polarity to solve this

One question. When the vehicle passes through the lane,

There will be a car with a car in the distance.

A signal with a opposite sign. This is in one

The ability to provide Lane conditions on the sensor is a major development.

Traffic sensors can monitor the speed, the number of axes, the weighing of the vehicle, the direction determination and the vehicle classification. Recently, this sensor has been proved to be useful on the runway of the airport. The output signal from the airport management personnel can observe the aircraft speed (two sensor delay time), direction, weight (including fuel), machine axle number, and aircraft wingspan (according to a fixed distance and speed of the two known intersensor obtained). This information can be used to classify the aircraft, to provide traffic control for the runway and to the safety of the airport.
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