Automotive Sensors and Application

Sensors play an important role in Automotives. All the sensors inside the car or vehicle are connected to the ECU (Electronic Control Unit). There are many sensors used in cars but we have discussed here a few Most common & important sensors. This article gives a brief about automotive sensors.

1) Oxygen sensors: The oxygen sensor (or O2 sensor) monitors the content of exhaust gases for the proportion of oxygen. The information is compared to the oxygen content of ambient air and is used to detect whether the engine is running a rich fuel ratio or a lean one. The engine computer uses this information to determine fuel metering strategy and emission controls.

2) Throttle Position Sensor: The throttle Position Sensor used to monitor the air intake of the engine. The sensor is usually located on the butterfly spindle/shaft so that it can directly monitor the position of the throttle. The TPS sensor is a potentiometer, providing a variable resistance depending on the position of the throttle valve.

3) Crankshaft Position Sensor: CKP is the sensor, without the operation of the fuel injection system is impossible. Defects in CKP inevitably lead to engine failure and the car will not run. The crankshaft position sensor (CKP) is an electromagnetic sensor with the help of which the fuel injection system makes synchronization of the fuel injectors operation and the ignition system. СКР sensor sends a signal for the speed and the position of the crankshaft to the onboard controller. This signal is a series of repetitive electrical voltage impulses, generated by the sensor when the crankshaft is rotating. Based on these impulses, the onboard controller controls the fuel injectors and the ignition system.

4) Mass Airflow Sensor: A mass airflow (MAF) sensor responds to the amount of air flowing through a chamber containing the sensor. It is intended to be insensitive to the density of the air. The sensor for volume consumption of air is used in many systems for the management of engines for measuring the value of the transitory cost of air. Air consumption is one of the basic parameters for calculating the necessary amount of fuel. MAF usually is placed after the air filter and before the throttle valve in the airflow sucked into the engine

5) Manifold Absolute Pressure Sensor:   MAP sensor (MAP) measures dilution in the intake manifold and its sensitive element converts the signal to electrical that can be returned to the onboard controller. The MAP sensor is used mostly as a cheap alternative to sensors for the engine load. Its relatively low cost is the reason for its wide distribution, though its measurements are not as accurate as of the various types of sensors for the amount of air. MAP can be located in the engine compartment as a separate component or integrated into the onboard controller. The manifold absolute sensor provides instantaneous manifold pressure information to the engine's electronic control unit (ECU).

6) Engine Coolant Temperature Sensor: A coolant temperature sensor (CTS) (also known as an ECT sensor or ECTS (engine coolant temperature sensor) is used to measure the temperature of the coolant/antifreeze mix in the cooling system, giving an indication of how much heat the engine is giving off. The sensor works with the vehicle’s ECU, continually monitoring the coolant temperature to make sure the engine is running at the optimum temperature.

7) Fuel Temperature Sensor: Fuel Temperature Sensor (FTS) is designed to measure the temperature of a vehicle's fuel and relay this information to the engine control unit, so that it can optimize the air-to-fuel mix ratio, depending on what the fuel temperature is with respect to the intake air temperature.

8) Vehicle Speed Sensor: this sensor gives the onboard computer information about the vehicle speed. The sensor operates on the principle of the Hall Effect and is usually mounted on the tachometer or in the gearbox

9) knock Sensor: A knock sensor is essentially a small “listening” device in or on the engine that detects these irregular vibrations and sounds that come from the engine block. The knock sensor picks up vibration and sound coming from the engine block, turns it into an electronic signal, and sends that signal to the engine control unit (ECU). The car’s computer then judges the information and determines whether or not ignition timing should be altered

10) Current Sensor: current sensor measures the current of the battery in the battery pack.

There are many sensors used in the car & not discussed here, for more detail please visit below references

References:

https://www.slideshare.net/jigneshparmar33/automotive-electronics-in-automobile-electronic-control-unit

https://www.electronicsforu.com/technology-trends/tech-focus/automobile-industry-sensor

https://autoditex.com/page/crankshaft-position-sensor-ckp-11-1.html

https://en.wikipedia.org/wiki/Automotive_electronics

https://mechanicbase.com/engine/car-sensors/

Ajit Nawale
Embedded Hardware Engineer
Devise Electronics Pvt Ltd