Until about 30 years ago a car had on average about five sensors. Today that figure can reach three 3,000, and only in the engine there are about 70. These ‘watch’ from the inflation of the tires, the oil level, the operation of the machine, and even watch over the safety and comfort of the occupants of a vehicle.
They are basically transmitters that inform the computer of the operation of the different components of the vehicle. That information -whether physical or chemical, such as temperature degrees, the amount of exhaust gases, or engine revolutions- is defined in data that is sent to the computer.
These received data are measured by the computer by their intensity, frequency, intensity or duration, with high precision. According to the reading of these parameters, they are contrasted according to the setting or setting originally established.
This information is generated when the engine is running and is stored to later detect if there is any significant change in the setting. If so, the car’s electronic system is responsible for warning through the so-called ‘witnesses’ turning on the alert on the dashboard.
This allows taking the appropriate measures to prevent or counteract a failure, thanks to the actuators, which are a complement to the sensors. That is to say, The first alert and the second correct, as in the case of the coolant temperature sensor, that the opening times of the injectors vary depending on the degrees to which the engine is exposed.
Another example that is easier to understand is that of the rain sensors, these ‘alert’ when the first drops of water fall on the windshield and the actuator immediately executes the order to activate the wipers.
Modern cars have at least 70 microprocessors in their engines that send information to a computer, which connects to a scanner that identifies the fault.
Sensors warn of faults and provide audible or visual alerts to the driver.
Sensor Classification
Although there is a large classification variable, in general these are divided into two categories: according to their function and according to the output signal emitted. In the first case, there are the sensors dedicated to control and regulation tasks, such as the ABS which, thanks to the control it exercises over braking, prevents the wheels from locking while keeping the steering functional. Security ones, such as anti-theft systems; and the sensors for the ‘surveillance’ of the state of the vehicle such as maintenance, oil changes or tire inflation pressure.
In the second category are those that are classified by their output signal. Signal ones, such as the flowmeter that measures liquid or air flows, such as turbo pressure or engine temperature.
There are also those of digital signal, which indicate the connection or disconnection of certain elements, such as the impulses of the Hall sensor revolutions. And those with a pulsating signal, such as the inductive ones that report the number of revolutions.
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