TOPIC 2. ELECTRONIC SYSTEM

1. TOPIC 2. ELECTRONIC SYSTEM • 2.1 Understand the Electronic Systems And Components LECTURER NAME: MR. KHAIRUL AKMAL BIN NUSI

2. Electronic Ignition Systems • Electronic ignition systems are made up of a primary and secondary circuit. The primary supports the initial start-up of the ignition switch, battery and primary coil windings. The secondary circuit supports the electronic control module, distributor cap, ignition coil and spark plugs.

3. Function • Turning the ignition key causes the battery to send current past the ignition switch; this energizes the primary coil windings. An armature within the coil assembly builds up power, and essentially transforms the low voltage into high voltage. This high voltage is distributed through the distributor cap and electronic control module. The voltage proceeds to the spark plugs for firing.

4. Induction Electronic Ignition Systems • This type of electronic ignition system contains a coil which stores the power necessary to create the spark that sets the engine in motion. When the ignition is activated, the power supply to the coil is shut off, which triggers the release of electrical energy. This very simple design is sometimes referred to as the "Kettering system," named after the inventor of the modern ignition system.

6. With the ignition switch turned on, primary (battery) current flows from the battery through the ignition switch to the coil primary windings. • Primary current is turned on and off by the action of the armature as it revolves past the pickup coil or sensor. As each tooth of the armature nears the pickup coil, it creates a voltage that signals the electronic module to turn off the coil primary current. • A timing circuit in the module will turn the current on again after the coil field has collapsed. When the current is off, however, the magnetic field built up in the coil is allowed to collapse, which causes a high voltage in the secondary windings of the coil. It is now operating on the secondary ignition circuit, which is the same as in a conventional ignition system.

7. A Hall effect sensor is a transducer that varies its output voltage in response to a magnetic field. Hall effect sensors are used for proximity switching, positioning, speed detection, and current sensing applications. • In its simplest form, the sensor operates as an analogue transducer, directly returning a voltage. With a known magnetic field, its distance from the Hall plate can be determined. Using groups of sensors, the relative position of the magnet can be deduced.

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9. Hall Effect Sensors

11. Distributor Hall Effect Type Used to show Engine Speed and Cylider Recognitioner • The Hall effect type Distributor Provides the speed and the cylinder potion of the engine. This type of Distributor replaced the earlier Points type Distributor. 

12. Hall Effect Operation • The Hall effect sensor is a simple switching circuit. The circuit is switched by a hall chip. The Hall Chip is located adjacent to a magnet and a drum mounted to the Distributor shaft rotates between the magnet and sensor. There are cut outs in the drum that allow the magnet to trigger the hall sensor. When a cut out passes between the magnet and the Hall sensor the magnetic field influences the Hall sensor. When a solid part of the drum passes the Sensor the magnetic filed is removed from the sensor. It is this action that produces the on/off switch. This signal is interpreted by the ignition module, Ignition control unit or Ecu as a square wave. • The sensor has 3 terminals marked +, - and 0  The + terminal is the Ecu to Sensor supply voltage. This will generally be 5 volts. The - terminal is the earth connection and should read 0 volts. The 0 Terminal is the signal voltage which is a square wave. The frequency of the signal increases with engine speed.

13. Optical Type Sensors • Optical Sensor.  • The optical sensor is usually located in the distributor. The rotor plate has many slits in it through which light passes from the light emitting diode (LED) to the photo sensitive diode (light receiving ). As the rotor plate turns, it interrupts the light beam from the LED to the photo diode. When the photo diode does not detect light, It sends a voltage signal to the ignition module, causing it to fire the coil.

15. 2.2 The Supplemental Restraint Systems ( SRS Systems )

16. Airbag • An airbag is a vehicle safety device. It is an occupant restraint system consisting of a flexible envelope designed to inflate rapidly during an automobile collision. Its purpose is to cushion occupants during a crash and provide protection to their bodies when they strike interior objects such as the steering wheel or a window

18. The IMPACTSENSORS are located on both sides of the front area of the vehicle. The sensors are very sensitive to impacts, and are designed to transmit the information of their activation to the airbag instantly. All the electrical contacts of the airbag system are gold plated to eliminate the possibility of corrosion forming.

19. Cars can be repaired . . . people are a little more difficult!!

20. seat belt • A seat belt, sometimes called a safety belt, is a safety harness designed to secure the occupant of a vehicle against harmful movement that may result during a collision or a sudden stop. A seat belt reduces the likelihood and severity of injury in a traffic collision by stopping the vehicle occupant from hitting hard against interior elements of the vehicle or other passengers (the so-called second impact), by keeping occupants positioned correctly for maximum benefit from the airbag, if the vehicle is so equipped, and by preventing occupants being ejected from the vehicle.

21. Types of pretensioner i. Mechanical Pre TensionerThis pre tensioner is operated mechanically. It is usually connected to the seat belt buckle assembly with a long powerful spring that is compressed in a tube and is kept compressed by a latching mechanism. If an accident occurs the impact causes the latch to release the spring which pulls on the buckle assembly and tightens the seat belt. ii. Electronic/Pyrotechnic Pre TensionerThis pre tensioner operates with an ECU and a gas generator system in a similar way to the airbag. In fact the electronic pre tensioner usually works together with the airbag and may even use the same ECU as the airbag and that increases its effectiveness.

23. Types of attachment 1. Two-point • A 2-point belt attaches at its two endpoints. • Lap • A lap ("2-point") belt in an airplane • A lap belt is a strap that goes over the waist. This was the most commonly installed type of belt and is primarily found in older cars. • Sash • A "sash" or shoulder harness is a strap that goes diagonally over the vehicle occupant's outboard shoulder and is buckled inboard of his or her lap. The shoulder harness may attach to the lap belt tongue, or it may have a tongue and buckle completely separate from those of the lap belt.

24. 2. Three-point • A 3-point belt is a Y-shaped arrangement, similar to the separate lap and sash belts, but unitized. Like the separate lap-and-sash belt, in a collision the 3-point belt spreads out the energy of the moving body over the chest, pelvis, and shoulders. 3. Belt-in-Seat (BIS) • The BIS is a three-point harness with the shoulder belt attached to the seat itself, rather than to the vehicle structure

25. 4. 4-, 5-, and 6-point • A 6-point harness in a racing car. • Five-point harnesses are typically found in child safety seats and in racing cars. The lap portion is connected to a belt between the legs and there are two shoulder belts, making a total of five points of attachment to the seat. A 4-point harness is similar, but without the strap between the legs, while a 6-point harness has two belts between the legs

26. Vehicle safety systems • Vehicle safety systems are designed to protect occupants during accidents, and can be classified as primary, or passive systems and secondary, or active systems. • Primary systems are ready to use in any accident. They include bumper bars, body panels, seatbelts, crumple zones and collapsible steering columns. • A secondary system has to be activated to work and is only necessary in severe accidents. The two most popular types of secondary systems are supplemental restraint system air bags, and seatbelt pre-tensioners.

29. Tire-pressure monitoring system • A tire pressure monitoring system (TPMS) is an electronic system designed to monitor the air pressure inside the pneumatic tires on various types of vehicles. TPMS report real-time tire-pressure information to the driver of the vehicle, either via a gauge, a pictogram display, or a simple low-pressure warning light. TPMS can be divided into two different types — direct (dTPMS) and indirect (iTPMS). TPMS are provided both at an OEM (factory) level as well as an aftermarket solution.

30. Indirect TPMS • Indirect TPMS do not use physical pressure sensors but measure air pressures by monitoring individual wheel rotational speeds and other signals available outside of the tire itself. First generation iTPMS systems utilize the effect that an under-inflated tire has a slightly smaller diameter (and hence higher angular velocity) than a correctly inflated one. These differences are measurable through the wheel speed sensors of ABS/ESC systems

31. Direct TPMS • Direct TPMS employ pressure sensors on each tire, either internal or external. The sensors physically measure the tire pressure in each tire and report it to the vehicle's instrument cluster or a corresponding monitor, sometimes also the temperature inside the tire. These systems can identify under-inflation in any combination, be it one tire or all four, simultaneously. Although the systems vary in transmitting options, many TPMS products (both OEM and aftermarket solutions) can display real time tire pressures at each location monitored whether the vehicle is moving or parked.

33. 2.3. Understand Security systems

34. Remote control keys

35. Remote control keys and key fobs transmit a coded signal that is received by the vehicles theft deterrent module. If the code meets preset criteria, the module closes a switch that enables either the drivers’ door or all doors to be locked and unlocked as required. • Pressing the button a second time when locking some vehicle activates the dead lock actuators and deadlocks the vehicle. • For the remote key and computer to exchange information, wireless communication is needed. High frequency electromagnetic fields known as “Radio Frequency” or RF is used

36. Theft deterrent systems • Theft deterrent systems aim to prevent the vehicle being entered, started or driven. The actuators used to achieve this are the electric door locks and windows, the starter motor relay, engine management systems, transmission shift solenoids, and an audible alarm. • The computer that controls the system monitors input signals from various devices. Switches are located at each door, the hood and trunk openings, and the fuel filler door. • Vibration sensors detect any unusual vehicle movement such as lifting, jacking or towing.

37. Ultrasonic sensors detect any movement inside the cabin. • Voltage monitoring sensors check against operation of the starter motor, ignition system or fuel pump. • The immobilization system is enabled by pressing the lock button on the remote key, locking the doors manually with the door key, or when a period of time has elapsed, typically 15 seconds, after the engine has stopped. The immobilization system is disabled by pressing the unlock button on the remote fob.

38. 2.4 Understand Entertainment And Peripheral Systems

39. Body controlled lighting systems • In modern vehicles ambient light sensors are used to automatically turn the headlights on in low light situations. Other body control lighting features can include: automatic 'dipping' headlights; delayed 'off' headlights; and headlight warning alarms.

40. Proximity sensors • Proximity sensors are mounted in the front or rear bumpers. The control unit determines the distance between the sensor and an obstacle by measuring the time taken for sound waves to leave and return to the sensor.

41. Reflective displays • Reflective displays use a mirror embedded in the dash so the instruments appear further away than they actually are. This way the driver's focal point changes less when looking from the road to the instruments and back.

42. Integrated communications • Modern vehicles integrate audio, video and communication systems into a network. This allows for a high quality, compact and ergonomic system, which combines entertainment features with simple operation. • Controls are centralized with hardware, such as CD stackers, and DVD players located remotely. • Communication between components uses a combination of hard wiring and data buses. • With data buses being used, audio messages can be broadcast over the audio system that relate to other vehicle systems. For example, a voice message can say “the park brake is on” or “left rear tire is under inflated”

43. 2.5. Understand Satellite assisted systems

44. The Global Positioning System or GPS uses a group of at least 24 satellites orbiting approximately 12 600 miles or 20 200 kilometers above the earth. The vehicle is equipped with a receiving antenna and computer system. The GPS receiver on the vehicle has to locate four or more of these satellites, determine the distance to each, and use this information to establish it's own location. This operation is based on a mathematical principle called “trilateration”.

46. The word  navigation is a combination of the Latin words navis, meaning a ship, and agere, meaning guidance.  Satellite Navigation in the context of Vehicle Telematics is a means of safely guiding a vehicle  to its destination. Traditionally finding your way involves, spreading a paper map inside the car Often, it isn’t easy to immediately know where you are. You try and find your bearings by looking for landmarks, checking the surroundings, or finding the names of intersecting streets before determining your current location.

48. Automotive telematics • Automotive telematics is a satellite-based system that combines two-way communication and information technology within the vehicle. The vehicle is equipped with a satellite transceiver enabling data to be sent to and from the vehicle. • Using this system allows for: vehicle tracking, monitoring of onboard systems, messaging, travel information, entertainment, security, safety and fleet management systems which monitor information such as location, distance traveled, speed, stops and fuel usage.

49. A vehicle manufacturer may offer telematics as a service to its customers. The benefits of this can include: the location & immobilization of a stolen or lost vehicle, notification to emergency services after SRS deployment, engine shut down and door unlocking in the event of a severe accident, roadside assistance and remote diagnosis.