Sensing and Monitoring Systems: Automobiles
- 1. Introduction Motorized vehicle consisting of four wheels and powered by an internal engine. Automobiles are used to transport people and items from one location to another location. After years or various designs, inventors were able to develop a functional general design that is utilized by major automakers as the foundation of their designs. Automobiles generally use gasoline to fuel the internal engine, but technological advances have led to the design of cars that run on electricity. What is an Automobile?
- 2. Why Sensors Required for Automobile Safety is a number one concern of vehicle customer. Safety equipment such as: Advancements in tyre and braking technology Through side impact protection and airbags. Driver Assistance System (DAS).
- 3. Sensors in Automobiles: Today’s modern automobiles have a variety of sensors. They built into their engine to ensure that the owner can identify and prevent possible issues before they result in breakdowns can result in expensive repairs. These automobile engine sensors also ensure that the vehicle is operating at its most efficient. Engine sensors are electro mechanical devices that operate and monitor the different engine parameters in real time. It provides data to the Engine Management System which helps in the changes supervised by the Engine Control Unit.
- 4. Fuel Gauge A fuel gauge is an instrument used to indicate the amount of fuel in a fuel tank. The gauge consists of two parts: The sensing unit - in the tank The indicator - on the dashboard The sensing unit usually uses a float connected to a potentiometer. As the tank empties, the float drops and slides a moving contact along the resistor, increasing its resistance. In addition, when the resistance is at a certain point, it will also turn on a "low fuel" light on some vehicles. The indicator unit (usually mounted on the dashboard) is measuring and displaying the amount of electric current flowing through the sending unit.
- 5. Speedometer A speedometer or a speed meter is a gauge that measures and displays the instantaneous speed of a vehicle.
- 6. Tachometer An instrument which measures the working speed of an engine (crankshaft) (especially in a road vehicle), typically in revolutions per minute. It works on the principle of a tachometer generator, which means when a motor is operated as a generator, it produces the voltage according to the velocity of the shaft. Types of Tachometer Analog tachometers Digital tachometers Contact and non-contact tachometers
- 7. Odometer An instrument for measuring the distance travelled by a wheeled vehicle. Most odometers work by counting wheel rotations and assume that the distance traveled is the number of wheel rotations times the tire circumference, which is a standard tire diameter times pi (3.1416).
- 8. Anti-Lock Braking System A safety system in automobiles that keeps their wheels from locking up and helps their drivers to maintain steering control. It enables the wheels of a vehicle to maintain tractive contact with the ground so that they don’t go into an uncontrolled skid. With ABS, you have more control on your car during situations such as sudden braking. Basically, it is designed to help the driver maintain some steering ability and avoid skidding while braking.
- 9. Airbags An airbag is a type of vehicle safety device and is an occupant restraint system. The airbag module is designed to inflate extremely rapidly then quickly deflate during a collision or impact with a surface. The sensor is the device that tells the bag to inflate. The sensors receive information from an accelerometer built into a microchip.
- 10. The Mass Air Flow Sensor (MAF) Calculates the volume and density of the air taken in by the engine. This in turn ensures the right amount of fuel is used for optimized operating conditions. If this sensor is faulty, the car may stall and the fuel usage will be higher than necessary.
- 11. Manifold Absolute Pressure Sensor A Manifold Absolute Pressure Sensor, or MAP, senses the engine load. It is mounted on the intake manifold & can measure the difference between the intake manifold pressure and outside. This is important for the engine to be able to adjust the fuel injection based on the change in pressure.
- 12. Throttle position sensor (TPS) Throttle shaft is attached with a potentiometer called TPS. This sensor is supplied with voltage and a voltage of varying current comes back. The voltage increases as the throttle opens. This variable voltage and the MAP sensor determines the amount of air which enters into the engine. This results in increase or decrease of the fuel rate as required. Nowadays, the throttle sensors, used in the automobiles, are of non-contact types, like magneto-resistive and inductive sensors.
- 13. Engine Speed Sensor Engine Speed Sensor is attached to the crankshaft and monitors the spinning speed of the crankshaft. Controls the fuel injection and timing of the engine. There are many ways for car engine to stop suddenly, and this sensor will prevent that for drivers. The device is basically a metal disk that has a serrated (toothed) circumference. In addition, there's a stationary device containing a magnetic coil, which acts as a standard for the measurement.
- 14. Oxygen Sensor Oxygen sensor, also known as Lambda sensor, monitors the amount of air in the exhaust. It determines whether the fuel-air ratio is rich or lean. It measures the difference between the oxygen in the exhaust and in the air. After determining it, it sends the information to Engine Control Unit, which supervises the amount of fuel to be injected into the system.
- 15. Spark Knock Sensor Engine knocking is a premature combustion of the compressed fuel, resulting in a sudden explosion. Spark knock sensors are used to prevent engine knocking. Knock Sensor uses Piezoelectric element. Knock Sensors generate a voltage when vibration is applied to them utilizing the piezoelectric effect. Knock sensors ensure that the combustion of fuel is going on, smoothly. It mainly detects the vibrations due to detonation. It is located on the cylinder head, engine block or intake manifold.
- 16. Fuel Temperature Sensor The fuel temperature sensor measures the amount of fuel injected into the cylinder. If the fuel is cooler, means its density is more, therefore, it will burn slowly. If the fuel is warm, then combustion will take place at faster rates. The Fuel Temp Sensor employs a thermistor to return a variable voltage to the ECU which is translated into a temperature reading by the ECU. Fuel temperature sensor basically supervises Engine Control Unit about the temperature of the fuel. According to the temperature, ECU injects the fuel.
- 17. Modern Technology In Automobiles Driving assistance systems: innovations on the way to autonomous vehicles Safety features such as Improved visibility Warns of potentially dangerous situation Possible Collision Objects Lane Direction
- 18. Light assist An automatic light adjustment assistant (light assist) increases the driving time with high beams. This is possible by the sensors installed in the front of the vehicle that identify the presence of a nearby vehicle and relay a signal to automatically switch to low beam, thereby preventing glare. Front assist Front assist helps prevent collisions with vehicles driving in the same direction. A sensor will monitor the traffic ahead of us and, in case it detects a possible collision, it will warn us with an acoustic signal and a visual popup on the dashboard.
- 19. Lane Assist This system recognizes the markings on the road so that if the vehicle crosses these markings, the system itself acts on the steering, correcting its position. At the same time, the system detects when the driver has his hands off the wheel for a few seconds; a sound and visual warning will activate so that the driver takes the car’s controls once again. Cruise Control Cruise Control is a system that automatically controls the speed of a motor vehicle. The system is a servomechanism that takes over the throttle of the car to maintain a steady speed as set by the driver. The driver must bring the vehicle up to speed manually and use a button to set the cruise control to the current speed.
- 20. Adaptive Cruise Control The ACC allows for the selection of a cruise speed, in addition to a minimum safety distance in relation to the vehicles ahead. The system will be in charge of decreasing or increasing the speed depending on the presence and distance of another vehicle.
- 21. Autonomous Driving Autonomous driving level 0 Driver only: the human driver controls everything independently. Autonomous driving level 1 Assisted driving: assistance systems help during vehicle operation (Cruise Control, ACC). Autonomous driving level 2 Partial automation: the operator must monitor the system at all times. At least one system, such as cruise control and lane centering, is fully automated. Autonomous driving level 3 Conditional automation: the operator monitors the system and can intervene when necessary. Safety-critical functions, under certain circumstances, are shifted to the vehicle. Autonomous driving level 4 High automation: there is no monitoring by the driver required. Vehicles are designed to operate safety-critical functions. However, the functions do not cover every driving scenario Autonomous driving level 5 Full automation: operator-free driving.