Computer Science – Automated and emerging technologies | e-Consult

In a traffic light controller, sensors, microprocessors, and actuators work together to manage the flow of traffic.

Sensors: The system uses vehicle detection sensors (e.g., inductive loops embedded in the road or cameras) to detect the presence of vehicles approaching an intersection. These sensors provide information about the number of vehicles waiting on each road.

Microprocessor: The microprocessor receives input from the vehicle detection sensors. It contains a program that dictates the sequence of traffic light changes. This program considers factors like the duration of green lights for each direction, and potentially adjusts timings based on real-time traffic flow (more advanced systems). The microprocessor determines when to switch between red, amber, and green lights for each direction.

Actuators: The traffic lights themselves (lights) are the actuators. The microprocessor controls the lights by sending electrical signals to them. These signals turn the lights on and off, indicating the appropriate traffic signal for each direction. The lights are directly controlled by the microprocessor's output circuits.

Diagram (Conceptual):

Interaction:

1. Vehicle detection sensors detect vehicles.
2. The sensors send signals to the microprocessor.
3. The microprocessor processes the signals and determines the appropriate traffic light sequence.
4. The microprocessor sends signals to the traffic lights to change their state.
5. The traffic lights illuminate, directing traffic.