CRUISE CONTROL SYSTEMSBy Yusha Patel
(TYME-A)
Cruise control is a new technological development which incorporates a factor of comfort in driving.Safety is only a small benefit of this system. In short, cruise control can be said to be a system which uses the principles of radar to determine the distances between two consecutive moving vehicles in which either one or both of them is incorporated with this system.
* Basic Information about Cruise Control Systems
*CONTENTS
*INTRODUCTION*WHAT IS CRUISE CONTROL ?*BASIC OPERATION*HOW TO SET CRUISE CONTROL?*ADAPTIVE CRUISE CONTROL*PARTS AND WORKING*DANGERS OF CRUISE CONTROL*FUTURE ASPECTS *CONCLUSION
*INTRODUCTION*Every minute, on average, at least one person dies in a crash. *Air bags and seat belts save tens of thousands of people a year.*But the ultimate solution and the only thing that will save far more
lives, limbs and money is ? till 1958.*Cruise control was commercially introduced in 1958 as an option on
the Chrysler Imperial.
*WHAT IS CRUISE CONTROL?
Cruise control is a system, which automatically controls the speed of an automobile.
The system takes over the throttle of the car to maintain a steady speed as set by the driver.
Most cruise control systems don’t allow the use of cruise control below a certain speed.
Blind inventor and mechanical engineer Ralph teetor invented cruise control in 1945.
BASIC OPERATION The basic operation of a cruise controller is to sense the speed of
the vehicle, compare this speed to a desired reference, and then accelerate or decelerate the car as required.
A simple control algorithm for controlling the speed is to use a "proportional plus integral" feedback.
The performance of the system is robust with respect to it’s mass uncertainty.
Block diagram of cruise control model
* HOW TO SET CRUISE CONTROL ?
*On &off
*set/accelerate
*Resume
• Coast
• Brake & clutch
* ADAPTIVE CRUISE CONTROL
*Adaptive Cruise Control (ACC) is an automotive feature that allows a vehicle's cruise control system to adapt the vehicle's speed to the traffic environment.
* In May 1998, Toyota became the first to introduce an ACC system on a production vehicle, luxury sedan.
*ACC systems detect the vehicle ahead through the use of either radar or lidar (light detecting and ranging).
*Lidar based ACC systems are limited due to their poor working in bad whether.
*PARTS AND WORKINGThe main components of a typical radar-based ACC system are *Fusion sensor*Headway control unit*Throttle*Brake*Dashboard display
Fusion sensor: It is a combination of sensors and processors. They are
*Millimeter-wave radar*Stereo camera* Image processor*Fusion processor
Architecture of a radar-based ACC system
*Millimeter wave radar: It is a sensor which uses millimeter wave for detecting the position and velocity of a distant object.
* Range is calculated using the formula C = 2*R/T Where ‘C’ is the velocity of light ‘R’ is the range ‘T’ is the time of flight of transmission.
*Stereo camera: The camera’s function is detection of cars and other objects in the roadway.
* Image processor: It processes the images from the stereo camera and the data fed into the fusion processor.
*Fusion processor: The function of fusion processor is Data Fusion.
Headway control unit: It has control on the brakes and throttle and uses dashboard for immediate warnings.
Canceling Cruise Control Operation:*Brake pedal is pressed* 'Off' button is pressed*Vehicle Speed < 25 mph*An ACC system fault is detected
A car model with advanced cruise control system
It’s use on wet and slippery roads may cause serious problems.
DANGERS OF CRUISE CONTROL
*FUTURE ASPECTS*CACC(co-operative adaptive cruise control) tested in California.
*At 100 km/hr, that would amount to a distance between cars of less than 14 meters (roughly two car lengths).
*Fujitsu Ten has demonstrated a prototype system for so called stop-and-go adaptive cruise control.
*CONCLUSIONS
*Fully autonomous car is probably not viable in the foreseen future.
*Near by vehicles would be in constant communication with each other and act co-operatively.
* It will probably take decades, but car accidents may eventually become almost as rare as plane crashes are now.
www.howstuffworks.com
www.cars.com/features/adaptivecruisecontrol
www.autorepair.com
http://en.wikipedia.org/wiki/Cruise_control
REFERENCES