Basics about ACC, How ACC works and getting upgraded in years.

1. Submitted to: Submitted By:
Mr. Parvesh Saini Sheetal Kapoor
Department of EE Mtech (III sem)
Control system
University Roll no. 1601542
Seminar
on
ADAPTIVE CRUISE
CONTROL

2. CONTENT
 Introduction
 Conventional Cruise Control
 Adaptive Cruise control
 Working of ACC
 Controller Action
 Vehicle Modelling Dynamics
 Advantage & Disadvantage
 Future Scope
 Conclusion

3. Introduction :
 Cruise Control technology was invented by Mechanical
Engineer Ralph Teetor granted patent in 1945.
 Maintains a steady speed regardless of inclines or
declines.
 Adaptive Cruise Control was in 1990 by William
Chundrlik .
 Currently available in luxury class cars like Mercedes S-
class , Jaguar, Volvo ,Baleno etc.

4. Conventional cruise control
 Also know as speed control or auto cruise.
 Adjust the throttle position to maintain a speed set
by driver.
 Benefit : for long drive , speed can be set near to
speed limit

5. Adaptive cruise control
 Controls the speed automatically according to the traffic
environment.
 Control is based on sensor information
 Installed radar allow the vehicle to accelerate and decelerate
accordingly .
 In emergency situation on the application of brake pedal the
cruise control systems are deactivated .
 ACC vehicle speed is controlled is via engine throttle control
and limited brake operation

6. How does acc work?

7. Controller action
Depending upon the traffic situation, two type of control
are possible :
 Speed control
 Headway Control

8. Definitions
 ACC vehicle – the subject vehicle equipped with
the ACC system.
 Active brake control – a function which causes
application of the brakes without driver application of
the brake pedal.
 Clearance – distance from the forward vehicle's
trailing surface to the ACC vehicle's leading surface.
 Forward vehicle – any one of the vehicles in front
of and moving in the same direction and traveling on
the same roadway as the ACC vehicle.
 Set speed – the desired cruise control travel speed
set by the driver under ACC control.

9.  Time gap – the time interval between the ACC vehicle
and the target vehicle.
Time gap = clearance / ACC vehicle speed
 Cruise Switches -Mounted on the steering wheel and
have several buttons which allow the driver to command
operation of the ACC system.
The switches include:

10. On': place system in the 'ACC standby' state
'Off'': cancel ACC operation and place system in the
'ACC off' state 'Set +': activate ACC and establish set
speed or accelerate
'Coast': decelerate
'Resume': resume to set speed
'Time Gap +': increase gap
'Time gap –': decrease gap

11. Physical layout
• ACC module
• Engine Control
Module
• Brake Control Module
• Instrument Cluster
• CAN
(Controller Area
Network)

12. Operational Overview

13. Cancelling Cruise Control Operation
 Operation may be cancelled by the operator or
automatically via the ACC system.
 Either of the following conditions will deactivate
ACC:
Brake pedal is pressed
'Off' button is pressed
Vehicle Speed < 25 mph
An ACC system fault is detected

14. Modelling a cruise control system
Using Newton’s 2 law
First order mass damper system will be
m dv/dt + bv = u (i)
&
we are interested in controlling the speed of the vehicle
output ,y = v (ii)
Where system parameter are,
M=1000kg,
B=50Ns/m,
U=5000N.

15. Advantage of ACC
 Travelling at a smooth and steady speed.
 Driver Comfort
 Fuel efficiency

16. Disadvantage/Risk involved :
 Wet roads significantly affect the grip of the tyre.
 In emergency situation driver inability to respond swiftly
& quickly.

17. Disadvantage/Risk involved :
 In congested traffic conditions , where speed varies
these system are no longer effective.
 Poor visibility.

18. Disadvantage/Risk involved :
 Driving over ‘rolling’ terrain
 In heavy rain, snow Radar will shut off.

19. Future Scope:
 COOPERATIVE ADAPTIVE CRUISE CONTROL
(CACC) here preceding vehicle can communicate
actively with the following vehicle .
 Providing vehicles that are wrapped in a cocoon of
sensors with a 360 –degree view of their surroundings
and a controller responding to it.
 Adaptive cruise control system is often paired with
a pre-crash system which alerts the driver and often
starts braking.

20. Conclusion:
 CC since 1958 has been easing some of the physical
strain of long distance driving.
 It works by adjusting the throttle automatically.
 Whereas ACC actually responds to the traffic.
 Makes driving safer and more pleasant.
But if you’re tired , weather is poor keep your cruise
control disengaged.
It’s better to be safe than sorry, after all.

21. YOU
thank