04-01-2013, 03:55 PM
A SEMINAR REPORT ON AUTOTRONICS: IMPROVING VEHICLE PERFORMANCE
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ABSTRACT:
The objective of this seminar report is to study the automobile application of autotronics and find its range of utilization and also to study how it will improve the performance of the vehicle. This report briefly describes a few automobile applications of autotronics mainly in following domains:
Braking system
Steering system
Suspension system
Transmission system
Engine (fuel intake)
INTRODUCTION:
Autotronics is the blend of Automobile +Electronics. The advanced development of vehicles in the last few years was based mainly on electrical and electronic componentsand modules. There is no end in sight to this development. All main functional areas are strongly influenced by the field of electronics or even made possible by it: e.g. anti-lock brake systems, low emission and reduced fuel consumption through electronic motor management systems, anti-theft and electronic diagnosis systems.Analysts estimate that more than 80 percent of all automotive innovation now stems from electronics.
For long-haul serial communication between various automotive subsystems such as anti-lock brakes, airbag deployment, engine
Control, and GPS navigation, the CAN, LIN, and MOST protocols are the most popular serial buses implemented in today’s vehicles. By definition, automotive
Electronic systems are embedded mixed-signal systems because they feature multiple analog sensors and analog motor controls under digital control. For years, traditional oscilloscopes have been the primary tool-of choice among automotive electronic system design engineers.
HISTORY:
The past four decades have witnessed an exponential increase in the number and sophistication of electronic systems in vehicles. Today, the cost of electronics in luxury vehicles can amount to more than 23 percent of the total manufacturing cost.Automotive electronics first began with the need for better controls for the engine. In fact, the first electronic part in an automobile was called an ECU which actually means” Engine control unit”, but as they used similar electronic control for other automotive application they called it the same ECU but with a more general meaning “Electronic control unit”. A modern car may have up to 100 electronic control units and a commercial vehicle up to 40.With the advances in technology and electronics, car manufacturers have been able to offer a wide variety of services and conveniences that many new automobile owners appreciate. From the creation of the Electronic Fuel Injection to the popular Global Positioning System found standard in many cars today, the auto industry has revolutionized the way people travel from place to place.In the mid-1980s, Bosch developed the controller area network, one of the first and most enduring automotive control networks. CAN is currently the most widely used vehicular network, with more than 100 million CAN nodes sold in 2000.The modern automobile has an extensive electrical system consisting of a large number of electrical, electromechanical, and electronic loads that are central to vehicle operation, passenger safety, and comfort. Power electronics is playing an increasingly important role in automotive electrical systems–conditioning the power generated by the alternator, processing it appropriately for the vehicle electrical loads, and controlling the operation of these loads.
NEED:
To understand the phenomenal growth of the automotive electronics in Asia Pacific, we first need to understand the evolution of this industry on a global front. To improve efficiency of system communication and to reduce cost, all of today’s automotive designs employ a variety of serial bus communication protocols. The I 2C and SPI protocols are most often used for chip-to-chip communication within electronic control units (ECUs). For long-haul serial communication between various automotive subsystems such as anti-lock brakes, airbag deployment, engine
Control, and GPS navigation, the CAN, LIN, and MOST protocols are the most popular serial buses implemented in today’s vehicles.By definition, automotive
Electronic systems are embedded mixed-signal systems because they feature multiple analog sensors and analog motor controls under digital control. For years, traditional oscilloscopes have been the primary tool-of choice among automotive electronic system design engineers to measure the quality of both analog and digital signals. But traditional analog and digital oscilloscopes have many limitations, including lack of complex serial triggering and limited input channels of acquisition. However, a new class of measurement tools called mixed signal oscilloscopes.
Braking system:
The demands made on braking systems are increasing steadily. Therefore, the development and introduction of an electronic braking system (EBS) is a logical step. EBS increases traffic safety through reduced stopping distance and improved brake stability. The full diagnosis and surveillance functions as well as the display of brake
Lining wear offer an effective fleet logistics. By actuating the brake pedal the driver
defines the deceleration request. The EBS ECU transmits this input electronically
To all braking system components. The braking system's shorter response timesprovide a more comfortable and finelytunedbraking feeling, independent of thevehicle’s load situation. EBS provides the basis for the integration of further safety systems like e.g. WABCO ESC (Electronic Stability Control). ESC is a system which independently intervenes in critical driving situations and adjusts engine and brake control. Within physical limits, ESC protects vehicles from rollover, skidding, spinning and jack-knifing.
The EBS contains the following renowned functions:
Endurance brake integration
The braking system has an integrated brake management function which
always regulates the endurance brake when the brake pedal is activated based on an
optimum delay of the vehicle. Optimum service brake wear is attained through the
distribution of endurance and service brake. This function is an important part of
delay control. The integration of endurance brake can be deactivated via the switch.
Anti-lock braking system (ABS):
The control logic determines from the wheel rotation speed whether one or
more wheels can be blocked and decides whether to decrease, maintain, or increase
the braking pressure on it.
Traction control system (TCS)
Just like in the ABS function, while the vehicle is in motion, the electronic
control system determines whether the wheels are in the stable area of the μ slip
curve. In case of wheel-spin, the engine output and/or driving axle wheel braking is
adjusted by the axle modulator via the CAN bus and engine control system. An
activated traction control system is displayed on the functions display.
Brake lining wear control
When the brake is applied partially, the braking pressure distribution is
adjusted, not withstanding the available wear signals, i.e. the detected wear difference.
The pressure on the wheel brakes with more lining wear is reduced slightly, whereas
the pressure on the wheel brakes with less lining wear is increased adequately, so that
there is no change in the overall braking rate required by the driver.
STEERING SYSTEM:
Electric Power Steering:
The use of electric power steering (EPS) systems is spreading rapidly thanks
to their fuel efficiency compared with hydraulic systems. As a result, the steering
feeling of EPS, which was a weakness, has been improved almost to the level of
hydraulic steering systems. The self-alignment estimation control uses both the EPS
sensor information and internally programmed EPS control information to estimate
the self-alignment torque that is generated between the vehicle’s tires and the road
surface.
Electronic Power Steering
Electrically powered steering uses an electric motor to drive either the power
steering hydraulic pump or the steering directly. The power steering function is
therefore independent of engine speed, resulting in significant energy savings.
A "steering sensor" is located on the input shaft where it enters the gearbox
housing. The steering sensor is actually two sensors in one: a "torque sensor" that
converts steering torque input and its direction into voltage signals, and a "rotation
sensor" that converts the rotation speed and direction into voltage signals. An
"interface" circuit that shares the same housing converts the signals from the torque
sensor and rotation sensor into signals the electronics can process.
SUSPENSION SYSTEM:
A vehicle's suspension system typically consists of the springs and shock absorbers that help to isolate the vehicle chassis and occupants from sudden vertical displacements of the wheel assemblies during driving. A well-tuned suspension system is important for the comfort and safety of the vehicle occupants as well as the long-term durability of the vehicle's electronic and mechanical components. The suspension systems in most vehicles on the road today are passive. The chassis of the vehicle is attached to the axles or wheel assemblies through coil springs or leaf springs that help to protect the chassis from sudden vertical forces applied to the wheels (e.g. due to bumpy roads, pot holes, etc...). The shock absorbers help to dissipate the energy applied to the springs and damp the oscillations that would normally occur when a brief excitation is applied to a mass-spring system.
SYSTEM :
This controls the transmission system; mainly it controls the shifting process
of the gears. For a better shift comfort, lower torque interrupt while shafting -these
electronics are used in a manual transmission. Many semi-automatic transmissions
which have a fully automatic clutch or a semi-auto clutch (only declutching) use
electronics for its operation and control. Also fully automatic transmissions use
controls for their operation.
Electronically controlled transmissions were introduced on BMW products in
1986 on 5 and7 series vehicles. Currently EH (Electro-hydraulic) transmissions are
offered on almost every production model (Except E46 M3 and E39 M5). EH
transmissions offer the following benefits the to driver:
• Increased driving safety by reducing fatigue. All shifts are automatic as opposed to
Manual transmissions which require more driver interaction.
• Increased fuel economy through use of lock up torque converter.
• Increased fuel economy through optimized shift points.
• Improved shift comfort by use of “Overlap Shift” technology (ZF).
• More available features through the use of CAN bus technology.
In addition to providing shift control, the TCM also adapts to changing
conditions within thetransmission by monitoring slip ratios and modifying line
pressure. This increases the life of the transmission and reduces maintenance and
adjustments. The TCM controls the operation of the Lock-Up Torque Converter
which further increases economy.
CONCLUSION:
A modern car may have up to 100 electronic control units and a commercial vehicle up to 40. With brilliant minds working in the auto industry, there are limitless possibilities to what the manufacturers will include in their products in the coming years. If we look to the technology and electronics that are being used in the military vehicles, we can often predict the services that will be in civilian vehicles in the near future. This tends to be a trend in the automobile industry and will likely continue as people always want and expect more from their cars.