ADAPTIVE CRUISE

CONTROL SYSTEM

CONTENTS

Introduction

Cruise Control

Adaptive Cruise Control

Principle

Components

Working

Improvement

Advantages

Disadvantages

Conclusion

References

Introduction Increased accident rates

On average at every minute one person dies in a crash

Costs add up to 3% of world’s GDP

The concept of assisting driver in the task of longitudinal

vehicle control is known as cruise control.

First car - Chrysler Imperial in 1958

Source : Driver's behavioral adaptation to ACC : The case of speed and time headway

Cruise Control

Cruise control - automatically controls the speed

of a motor vehicle.

Also known as speed control or auto cruise.

The conventional cruise control has one mode of

control, velocity control.

Throttle position is adjusted to maintain a speed

set by the driver.

Improves driver comfort in steady traffic

conditions.

Cruise Control

The conventional cruise control is capable of only

maintaining a set speed by accelerating or

decelerating the vehicle.

The driver always has to apply brake when

approaching the target vehicle proceeding at a

lower speed.

In congested traffic conditions where speeds vary

widely these systems are no longer effective.

Adaptive Cruise Control

ADAPTIVE CRUISE CONTROL is a common

term used for enhanced cruise control system.

Collision-avoidance system

Assists the driver to keep a safe distance from

the preceding vehicle by controlling the engine

throttle and brake.

Free the driver from frequent accelerations and

decelerations and also reduces the stress of the

driver.

Adaptive Cruise Control

Operates in two modes :

Cruise mode : Speed of the vehicle is

controlled to maintain a set speed.

Follow mode : Speed of the vehicle is

controlled to maintain a set distance from the

preceding vehicle.

The driver can over-ride the system at any time.

Effective in the speed between 30km/h-180km/h

Adaptive Cruise Control If 25% vehicles driving in a highway were equipped

with the ACC system, traffic congestions could be

avoided.

In May 1998, Toyota became the first to introduce

an ACC system on a production vehicle, luxury

sedan.

Source : Development and testing of a fully Adaptive Cruise Control system

Working Principle

Works by detecting the distance and speed of the

vehicles ahead by using either a LIDAR system or

a RADAR system.

The time taken by the transmission and reception

is the key of the distance measurement.

The shift in frequency of the reflected beam by

Doppler Effect is measured to know the speed.

Depending on this speed, the brake and throttle

controls are done to keep the vehicle in a safe

position.

Doppler Effect

Doppler Effect is the change in frequency of the

waves when there is a relative motion between

the transmitting and receiving units.

The Doppler Effect can be categorize in two

ways:-

Higher Pitch Sound Vehicle speeding towards the stationary listener.

The distance between the listener and the car is

decreasing.

The listener will hear a higher pitch sound from

the car, which means the frequency of sound, is

increased.

Source : Nassaree Benalie et al. (2009), Improvement of ACC System based on Speed Characteristics and Time Headway.

Lower Pitch Sound Vehicle moving away from the listener.

The distance between listener and the car is

increasing.

The listener will hear a lower pitch sound from

the car, which means the frequency of sound, is

decreased.

Source : Nassaree Benalie et al. (2009), Improvement of ACC System based on Speed Characteristics and Time Headway.

Working Switch on ACC.

Set speed.

Sensors detects vehicle ahead.

Decelerate to ahead vehicle speed.

Keeps safe distance

Source : Paul John King et al. (2000), Adaptive cruise control system

Source : Paul John King et al. (2000), Adaptive cruise control system

Source : Paul John King et al. (2000), Adaptive cruise control system

Block diagram showing configuration

of an ACC

Source : Tanimichi et al. Adaptive Cruise Control System

Components

Sensors

Longitudinal controller receives the sensor data

and process it to generate the commands to the

actuators using Control Area Network (CAN) of

the vehicle.

Electronic vacuum actuator

Source : Gennaro Nicola Bifulco et al., Development and testing of a fully Adaptive Cruise Control system

Sensors

In this project three type of SENSOR can be used

Kept behind the grill of the vehicle.

Obtains velocity, distance, angular position and

lateral acceleration.

LIDAR LIDAR stands for “Light Detection and Ranging”.

By measuring the beat frequency difference

between a Frequency Modulated Continuous light

Wave and its reflection.

Source : Greg Marsden et al. (2000), Towards an understanding ofadaptive cruise control

LIDAR

It measures distance by illuminating laser and

analyzing the reflected light.

Low cost

Provides good angular resolution

Weather conditions restrict its use to 30 - 40

meters range.

RADAR

It operates by radiating energy into free space and

detecting echo signal reflected from an object.

Currently used “Pulse Doppler RADAR” uses the

principle of Doppler effect.

Current ACC systems are based on 77GHz

RADAR sensors.

Detects moving object up to 120m.

Work in poor weather conditions.

Block Diagram of Pulse Doppler Radar

Source : Greg Marsden et al. (2000), Towards an understanding of adaptive cruise control

Fusion Sensor Millimeter wave RADAR linked to a stereo type

camera with a 40 degree view angle.

These two parts track the car from non moving

object.

It was first used by Fujitsu Ltd. and Honda.

Source : S. Paul Sathiyan et al. (April, 2013), A Comprehensive review on Cruise Control for Intelligent Vehicles

Detection of Vehicle Edges by the

Fusion Sensor

Source : Seminar Topics.com/Adaptive Cruise Control System

Sensing and Controlling Process

Source : Greg Marsden et al. (2000), Towards an understanding of adaptive cruise control

Development of ACC Stop and Go Adaptive Cruise Control :

Works primarily at lower speeds in heavy traffic.

If the car in front stops, it will bring vehicle to a complete stop

Co-operative Adaptive Cruise Control :

The preceding vehicles can communicate actively with the

following vehicles so that their speed can be coordinated with

each other.

Source : Gennaro Nicola Bifulco et al. (2011), Development and testing of a fully Adaptive Cruise Control system

Advantages Driver is relieved from careful acceleration,

deceleration and braking in congested traffics.

Accidents can be reduced.

It’s very useful for long driving.

Can avoid unconsciously violating speed limits.

Increased fuel efficiency.

Source : Google.com/Images

Disadvantages High Cost.

Not for heavy traffic.

Encourages the driver to become careless.

Dangerous in slippery roads.

A high market penetration is required if a society of

intelligent vehicles is to be formed.

The ACC systems not respond directly to the traffic

signals.

Source : S. Paul Sathiyan et al. (April, 2013), A Comprehensive review on Cruise Control for Intelligent Vehicles.

Conclusion Current system ranges 150 meters can stop and

slows if any obstruction.

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 rare.

References1. S. Paul Sathiyan et al. (April, 2013), A Comprehensive review on

Cruise Control for Intelligent Vehicles. In: International Journal ofInnovative Technology and Exploring Engineering (IJITEE)

2. Gennaro Nicola Bifulco et al. (2011), Development and testing of afully Adaptive Cruise Control system

3. Nassaree Benalie et al. (2009), Improvement of Adaptive CruiseControl System based on Speed Characteristics and TimeHeadway. In: International Conference on Intelligent Robots andSystems

4. Giulio Francesco Bianchi Piccinini et al. (2014), Driver's behavioraladaptation to Adaptive Cruise Control (ACC): The case of speedand time headway

5. Greg Marsden, Mike McDonald, Mark Brackstone (2000),Towards an understanding of adaptive cruise control

6. Paul John King et al. (2000), Adaptive cruise control system

7. www.howstuffworks.com

8. www.youtube.com

Questions?

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