The SmartSensor Advance is able to do something no other advance detector can do. It calculates real-time ETA information on each vehicle that approaches, but just how does that work?
SmartSensor Advance creates a radar beam with a large vertical beam width and narrow horizontal beam width. The large vertical beam width allows Advance to be mounted high in the air and still track both near and far vehicles at the same time. The purpose of getting it high in the air is to prevent near vehicles from blocking detection of far vehicles.
The sensor transmits hundreds of radar pulses each second to detect the range and measure the speed of each vehicle it can see. The range and speed can then be used to estimate the time-of-arrival of the vehicle to the stop bar.
During sensor configuration using SmartSensor Manager Advance, a user configures the sensor to know the sensor’s distance from the stop bar.
When the Advance sensor detects a vehicle, it measures the distance from that vehicle to the sensor. Knowing the distance of the stop bar to the sensor, the sensor can then determine the distance from the detected vehicle to the stop bar.
Vehicle distance from stop bar (ft) = vehicle distance from sensor (ft) – stop bar distance from sensor (ft)
The sensor tracks detected vehicles and determines the speed at which they are moving. Once a vehicle’s speed and distance from the stop bar are known, the sensor can calculate how long it will take the vehicle to reach the stop bar.
The result of that time calculation is the Estimated Time of Arrival (ETA) that the Advance sensor bases its dilemma zone protection on.
ETA seconds = vehicle distance from stop bar (ft) / vehicle speed (ft / second)
The ETA estimates are continuously updated to determine if there are any vehicles within the broad span of ETAs that constitute the decision dilemma zone.
By continuously tracking the ETA, this helps protect each vehicle based upon its individual dilemma zone. It is a dynamic system that adjusts for vehicles that are accelerating or decelerating. If there are vehicles in the dilemma zone, the sensor communicates to the controller to extend the green light if possible.
SmartSensor Advance measures the range to a vehicle and using the offset, height and stop bar location calculates the vehicle’s distance to the stop bar. It also tracks the vehicle for a speed measurement and uses the vehicles speed and distance from the stop bar to calculate the time of arrival.
SmartSensor Advance begins detecting individual vehicles from 600 to 900 feet in advance of the stop bar.
One device detects the dynamic ETA for every single vehicle at the approach.
SmartSensor Advance detects the presence of each vehicle at the approach and measures its speed and location.
SmartSensor Advance continuously tracks the speed and range of an individual vehicle to determine their estimated time of arrival at the stop bar.
ETA can vary dramatically with different speeds. SmartSensor Advance uses more vehicle speed and range to continuously calculate estimated time of arrival at the sop bar for each vehicle.