The automobile of the late twentieth century is a technological hybrid that Henry Ford would have marveled at - a sophisticated blend of mechanics and electronics. Virtually all cars that are made in the world today have onboard microprocessors. Originally developed to help cars meet government standards for fuel efficiency and emission control, automotive computers now perform a wide range of tasks, from improved handling and stability to creating a more comfortable environment for the occupants.

In a so-called smart car, microprocessors are separately assigned to oversee and assist different mechanical systems, such as the engine, the brakes, or the suspension; their circuits are programmed to recognize certain conditions and take appropriate action in response. Essential to the process is a constant supply of information about operating conditions and the particular system’s performance. An extensive network of sensors provides that input, transmitting data as electrical signals for the computers to analyze. Completing their calculations at lightning speed, the computers the fire off instructions to actuators - electronically controlled devices such as motors, pumps, and valves - to effect the necessary adjustment. Corrections occur continuously, producing an unparalleled level of fine-tuning.

All this electronic activity calls for wiring throughout the car, which means added weight and increased chance of something going wrong. Designers, however, have minimized the problem through multiplexing, the same technique used to transmit many telephone conversations over a single cable. Signals from several sensors are combined and travel together over one transmission line; the receiving computer unscrambles the messages, analyzes the data, and in the space of perhaps a thousandth of a second, makes decisions that will keep the car working its best.

1 A Gallery of Sensors

Without effective sensors even the most powerful computers could do little to improve an automobile’s performance. The six most common automotive sensors:

1. Rotation sensor- designed to record the rate at which something spins.

2. Position sensor- indicates the location of a moving part by varying the resistance in an electrical circuit.

3. Temperature sensor- measures temperature of a gas or a liquid through variations in a circuit’s resistance

4. Airflow sensor- measures the air fed to the engine through the intake manifold

5. Knock sensor: detects uneven fuel burning, that causes irregular vibration in the engine.

6. Oxygen sensor- measures how much oxygen is in the exhaust, and thus how well the fuel is burning.

2 Anti-lock brakes

Without warning, a thunderstorm’s wind and rain lash at a car proceeding along a narrow road. Peering through the deluge as he rounds a curve, the driver suddenly sees another automobile pulling out of a driveway just ahead. He slams his foot against the brake pedal, half-expecting to skid out of control on the slick road. Instead, the car comes to a rapid, straight, and safe stop.

Credit for the automobile’s perfect performance belongs not to the driver, or even to luck, but to a computer linked to a quartet of electronic sensors tucked near the wheels. Each sensor performs a one-dimensional role: it monitors the velocity of a wheel and sends this information digitally to a computer. In a flash, the computer analyzes the data from the four sensors, judges whether any of the wheels is about to stop turning, and then signals the braking system to briefly relax its efforts to stop the car.

In effect, the computer does what every driver is taught to do under similar conditions: pump the brakes to avert a skid. But unlike the driver, the computer can be depended upon to do it perfectly every time - up to ten times a second.

3 Getting the Most from the Engine

By far the most prominent role played by automotive computers is regulating the car’s engine to optimize performance and at the same time improve both fuel economy and pollution control. The advent of electronics has come at the expense of two venerable engine components - the carburetor and the distributor - both rapidly disappearing from the automotive world.

A computer has also assumed control of ignition - the firing of the spark plugs. An ignition computer regulates each plug individually. Should one plug misfire, the computer can fine-tune the timing to coordinate the actions of all the pistons, virtually guaranteeing a more efficient production of power.

4 Electronic Fuel Injection, or EFI

From: http://www.thepeoplehistory.com/carelectronics.html

One of the best innovations that electronics have created in the performance of automobiles is the Electronic Fuel Injection, or EFI for short. This device takes the place of the normal carburetor that has been the normal until recently. The job of the carburetor was typically the part of the engine that helps to evaporate fuel so that it mixes with the air for combustion. This provides power to the cylinders which helps the engine operate. A floating device within the carburetor is used to regulate the amount of fuel that the engine receives.

The EFI, on the other hand, uses a completely different technology to supply power to the engine. Instead of a floater that regulates the fuel to the engine, the EFI system electronically meters the fuel so that the exact amount needed is provided to the engine. In short, the EFI uses to fuel to power the engine by pumping it forcibly by using high pressure through a small nozzle or valve. This is how the EFI supplies the proper amount of fuel to the combustion process. The EFI system provides a great deal of benefits over the carburetor, too. Not only does this new technology prevent the engine from flooding by allowing too much fuel into the engine, but it is also more efficient and emission-friendly. The EFI system is also compatible with alternative fuels and it is more reliable than the traditional carburetor. You will also notice a smoother ride and more engine power with an EFI system.

5 Steering with all Four Wheels

Four-wheel steering, a feature of most new cars, represents a dramatic improvement in handling over the conventional front-wheels-only approach. And properly coordinating the actions of the front and rear wheels is a task ideally suited to the precision monitoring and control a computer can offer.

At speeds of more than about 20 mph, an automobile’s front-wheel-steering computer ensures that both sets of wheels turn in the same direction. Because the rear wheels contribute to the maneuver rather than pointing straight ahead and being, in effect, dragged through the curve, stability is enhance. At lower speeds, however, the rear wheels are directed to turn in opposite to the front wheels, which reduces the car’s turning radius, thus improving maneuverability in city traffic, for example, and making it much easier to squeeze into narrow parking spaces.

6 Adjusting the Shocks on the Go

Road conditions can vary tremendously in the course of a journey, from the city’s bumps and potholes to the highway’s smooth paving. Under the control of a computer, a smart car’s suspension can adapt to these changes, continuously working out the best compromise of stability and comfort.

The sensors report on the action of each wheel’s suspension, and enable the computer to judge the surface the car is traveling on at any given moment. The computer can then alter the give in the shock absorbers to match the conditions.

7 Computerized Comfort

A computerized-controlled seat automatically adjusts to suit the preference of two different drivers by matching preselected settings. Seat height and the position of the reclining back can be adjusted, as well as the forward and backward position.

The chief advantage of a computerized climate-control system is its ability to adapt to circumstances automatically. On cold days, for example, the computer turns on front and rear defrosters as soon as the car is started. When the engine is warm, the heater is activated and the blower fan is turned on high until the desired temperature is reached.

8 Keeping the Driver Informed

In a smart car, a good deal of that information is relayed to the driver through the car’s instrument is also relayed to the driver through the car’s instrument computer. This computer not only reports such standard readings as the vehicle’s speed and fuel level but plays a diagnostic role as well. By constantly monitoring all the other computers and their components, it can give the driver early warning when something goes wrong.

Computerized navigation systems are also available, showing local maps and preferred routes to a destination. Steering and speed sensors help the computer track the car’s location from a starting point indicated by the driver.

A car repairman must now use a computer to diagnose engine trouble; signaling the end of the backyard mechanic.

9 Computer Diagnostics

From: http://www.thepeoplehistory.com/carelectronics.html

The field of computer diagnostics has also helped to shape the way that automobile owners use their cars. The cars manufactured in the last couple decades have been built with a computer on-board to help owners realize engine problems or other problems before any damage is done. Before the computer diagnostics technology, most car owners did not know something was wrong with the engine until something drastic happened, such as overheating or running out of gas. Mechanics generally had to endure a trial-and-error method to find out what was the problem in many cases.

Now, however, computers in the cars constantly check the engine and its components to make sure it is always up to its optimum performance. When a problem arises, a corresponding light in the dashboard comes on so you know to take it to the mechanic as soon as possible. The computers use many sensors to detect temperature, fluid levels and many other aspects of an engine’s performance. Many times, the computers in the car will provide a code that mechanics can read so they know exactly what has malfunctioned. They have state-of-the-art equipment that they can attach to the car and find out the reason for the malfunction. While this is a very convenient solution to many engine problems, it does require very expensive equipment, such as oscilloscopes, a digital volt-ohm meter, sensor stimulators and high-tech computers to determine problems. It also requires extensive knowledge about how to use the technology. Mechanics often need to go through training to use this method.

10 Airbags

From: http://www.thepeoplehistory.com/carelectronics.html

Another improvement in safety that electronics have provided is the airbags that are now standard in cars. Technically known as a Supplementary Restraint System (SRS), Air Cushion Restraint System (ACRS), or a Supplemental Inflatable Restraint (SIR), these provide a great deal of safety for the driver and passengers in a car. Created in 1952, the air bag technology is based on electronic sensors that measure the amount of quick deceleration through an accelerometer. This is a small electronic chip that moves as a result of fast deceleration and, as a result, signals the rapid ejection of the airbags. Car manufacturers are currently working on new airbag calculations to make them more effective and to help prevent unnecessary deployments. The new calculations will take into account the position of the seats, the use of a seat belt and the weight of the occupants to help determine when (and if) the airbag should be deployed.

11 Global Positioning System (GPS)

From: http://www.thepeoplehistory.com/carelectronics.html

The Global Positioning System (GPS) is a popular device that has made a splash in automobile electronics in recent years, too. These are basically electronic navigation devices that use satellites to monitor many aspects of an automobile. By using satellites, the GPS company can find the location of your car, the direction it is moving and the speed at which it is moving. As a result, your car can easily be found if it is stolen. The idea for this technology was first created in 1978 and used as an experimental device for the United States Department of Defense. Like most automobile technology, though, the idea quickly made its way into the civilian vehicles due to popular demand. A GPS will also give you step-by-step voice directions to your destinations, which tends to be the most popular feature of this electronic device. It can also come in handy if you lock your keys in your car. With a simple call to the GPS service provider, a representative can send a satellite signal to your car and unlock the doors. These devices are also great in a wide variety of emergencies, so they provide peace of mind in addition to safety and convenience.

12 Hybrid Cars

From: http://www.thepeoplehistory.com/carelectronics.html

This section would not be complet without talking about the electronics that is required to drive a Hybrid vehicle and one of the best examples is the Toyota Prius. This car uses the computer and digital electronics to manage the change between the differing combinations of power sources and due to electronics is pretty seamless if it weren’t for the energy consumption screen located in the Prius’ center console the driver would have little indication the complexity of it all this technology is called Hybrid Synergy Drive (HSD).

13 Some interesting history…

1930: Galvin Manufacturing Corporation (now Motorola) introduced the Motorola radio, one of the first commercially successful car radios.

1969: Volkswagen introduces the first on-board computer system for diagnostics with scanning capability, in their fuel-injected Type 3 models.

1995: Oldsmobile introduced the first GPS navigation system available in a production car, called GuideStar

1995: Onstar is founded and starts bringing many different hardware options to customers. Hardware that has been produced presently includes remote ignition block, Stolen vehicle tracking.

2004:  Advanced Parking Guidance System (APGS) for Lexus models in the United States, is the first production automatic parking system developed by Toyota Motor Corporation

2009: Cadillac offers a service called Cadillac Wifi