Electric cars are something that shows up in the news all the time. There are several reasons for the continuing interest in these vehicles: Electric cars create less pollution than gasoline-powered cars, making them an environmentally friendly alternative to gasoline-powered vehicles (especially in cities). Any news story about hybrid cars usually talks about electric vehicles as well. Vehicles powered by fuel cells are electric cars, and fuel cells are getting a lot of attention right now in the news. An electric car is a car powered by an electric motor rather than a gasoline engine. From the outside, you would probably have no idea that a car is electric. In most cases, electric cars are created by converting a gasoline-powered car, and in that case, it is impossible to tell. When you drive an electric vehicle, the only thing that clues you in to its true nature is the fact that it is nearly silent. Under the hood, there are a lot of differences between gasoline and electric cars: An electric motor replaces the gasoline engine. The electric motor gets its power from a controller. The controller gets its power from an array of rechargeable batteries. With its fuel lines, exhaust pipes, coolant hoses, and intake manifold, a gasoline engine tends to look like a plumbing projeHowever, an. An electric car is a wiring project. In order to get a feeling for how electric cars work in general, let's start by looking at a typical electric vehicle to see how it comes together.
Engine Control Unit
An ECU (Engine Control Unit) is also known as PCM (Powertrain Control Module). ECU is an electronic control unit that controls a series of actuators on an internal combustion engine to ensure optimal engine performance. In modern cars, it is almost impossible to build an emission-passing car without an ECU. A modern ECU might contain a 32-bit, 40-Mhz processor. The code in an average ECU takes up less than 1 megabyte of memory. ECU controls everything, such as air/fuel ratio, ignition timing, idle speed, variable valve timing, etc.
• Control of Air/Fuel Ratio
For an engine with fuel injection, an engine control unit (ECU) will determine the quantity of fuel to inject based on a number of parameters. If the throttle position sensoshowsng the throttle pedal is pressed further down, the mass flow sensor will measure additional air being sucked into the engine. The ECU will inject t fixed quantity of fuel into the engine (most of the engine fuel inlet quantity is fixed). If the engine coolant temperature sensor is showing the engine has not warmed up yet, more fuel will be injected (causing the engine to run slightly 'rich' until the engine warms up). Mixture control on computer-controlled carburetors works similarly but with a mixture control solenoid or stepper motor incorporated in the carburetor's float bowl.
• Control of Ignition Timing
A spark-ignition engine requires a spark to initiate combustion in the combustion chamber. An ECU can adjust the exact timing of the spark (called ignition timing) to provide better power and economy. Suppose the ECU detects knock, a condition that is potentially destructive to engines, and determines it to be the result of the ignition timing occurring too early in the compression stroke. In that case, it will delay (retard) the timing of the spark to prevent this. Since knock tends to occur more easily at lower rpm, the ECU may send a signal for the automatic transmission to downshift as a first attempt to alleviate knock.
• Control of Idle Speed
Most engine systems have idle speed control built into the ECU. The engine RPM is monitored by the crankshaft position sensor, which plays a primary role in the engine timing functions for fuel injection, spark events, and valve timing. Idle speed is controlled by a programmable throttle stop or an idle air bypass control stepper motor. Early carburetor-based systems used a programmable throttle stop using a bidirectional DC motor. Early TBI systems used an idle air control stepper motor. Effective idle speed control must anticipate the engine load at idle.
A full authority throttle control system may be used to control idle speed, provide cruise control functions and top speed limitation.
• Control of Variable Valve Timing
Some engines have Variable Valve Timing. In such an engine, the ECU controls the time in the engine cycle at which the valves open. As a result, the valves are usually opened sooner at a higher speed than at a lower rate. This can optimize the flow of air into the cylinder, increasing power and fuel economy.
Hybrid cars
Hybrid cars are the most important evolution to a Carbon Neutral way of driving because you only drive a short way most of the time. So you can go full electric, and also it’s possible to have a longer range with the combustion engine. There are different types of the concept for hybrid power cars.
Different system structures
• Series hybrid: Series-hybrid cars are driven by the electric motor with no mechanical connection to the engine. Instead, there is an engine for running a generator to get the energy for the electric motor.
• Parallel hybrid: In a parallel hybrid car, the single electric motor and the internal combustion engine are installed such that they can power the vehicle either individually or together.
• Power-split hybrid: In a power-split hybrid electric drive vehicle, there are two motors, an electric motor, and an internal combustion engine. The power from these two motors can be shared to drive the wheels or regenerate power for the batteries.
Different Hybrid types
• Mild hybrid: These types use a generally compact electric motor to provide auto-stop/start features and to provide extra power assist during the acceleration, and to generate on the deceleration phase
• Full hybrid: Full hybrid vehicles with an electromotive power of more than 20 kW / t can purely drive on electric power, and therefore it is the basis for a series hybrid.
• Plug-in hybrid: The plug-in hybrid is usually a general fuel-electric (parallel or serial) hybrid with increased energy storage, usually through a li-ion battery, which allows the vehicle to achieve a full-electric drive mode. The distance depends on the battery size and its mechanical layout.
Sensors and Radar
There are a lot of sensors and radar systems in our cars. We use them every day, mostly we don’t know that they exist. The most popular sensors are parking-, fuel-, temperature- and ultrasound sensors. The word sensor comes from Latin and means feel. It is a component that can detect physical or chemical properties, such as Sunshine, temperature, pressure, brightness, PH, Ion-Intensity, and much more. In the following, I will explain the most popular sensor in a car: 1. Parking Sensors Parking Sensors measure the distance between you and another car. In the beginning, they started with passive systems. For example, there were extra flexible components at the fender at a lorry, which the driver can use as landmarks by parking. But today, we have mostly active systems:
Ultrasound Systems
Ultrasound Systems are mounted at the bumper of the car. You can distinguish between 2-, 4- or 6-Sensors. The more sensors, the more accurate. These sensors send and receive ultrasound. In this way, the Signals will be evaluated from the control unit. The control unit compares the sender signals with the receiver signals and calculates the distance. Toyota produced the first working ultrasound system in a car in 1982 for middle-class Corona.
Radar Systems
Parking aid with radar systems is possible since the development of the short wave millimeter-wave radar. The method is the same as the ultrasound system. But here, you don’t need extra sensors in the bumper. The distance adjustment system will also be used for parking aid. You won’t have additional costs, but sometimes when it’s raining, the radar system gives you wrong signals because the water is running on the bumper.
Airbag
The Airbag was created to reduce the danger of injury during a car crash as low as possible. The owner of the Patent is Walter Linderer, and he created the airbag in 1951. In general, the Airbag is controlled by an airbag-control system. Crash sensors control this. To not start the airbag by accident, there are also sensors in the car that send signals depending on how hard something collides. If those sensors get activated, the airbags pop out of their case and protect drivers and co-drivers.
Sources
1. Parking aid: 18.01.2015 at 1:17pm
http://de.wikipedia.org/wiki/Einparkhilfe
2. Sensors: 18.01.2015 at 2:38pm
http://www.kfztech.de/kfztechnik/elo/sensoren/sensoren.htm
3. Sensors: 18.01.2015 at 4.03pm
http://de.wikipedia.org/wiki/Sensor
4. Engine Control Unit: 21.01.2015 at 10.53 am
http://en.wikipedia.org/wiki/Engine_control_unit
