This document describes the modeling and implementation of an adaptive cruise control (ACC) system for vehicles. It discusses the components of ACC including radar sensors, a controller, actuators for braking and throttle control, and a user interface. It also covers modeling the ACC system using equations of motion and Laplace transforms. The document concludes by discussing hardware implementation of the braking system and potential future work such as additional testing and applications to other vehicle types.

1. Throttle Automation And Implementation
of Adaptive Cruise Control
A Step towards automatic vehicle
Done by:-
Anand Krishnan M (107)
Anzil N S (111)
Rajesh S L (163)
Vineeth G L (177)
Vineeth V Kumar (178)

2. Overview
• Introduction
• Components
• Modelling
• Simulation
• Design
• Implementation
• Further Work
• References

3. What’s ACC?

4. Unique Features of System
• Adaptive – Deceleration Rate
• Safety – Collision Avoidance
• Automatic – Throttle, Braking

5. Features
• Forward-looking Radar
• Preset and maintain the car speed
• Measure the distance to the preceding car and
the relative speed
• Adjust the car speed accordingly
• Brake-Throttle Control

6. The ACC Application

7. Components
• ACC Sensors
• Radar – Senses Obstacles in front of host vehicle.
• Speed – Senses Speed of host vehicle.
• ACC Controller
• Controls the digital logic of the system
• ACC Actuators
• Brake – Actuates Brakes of host vehicle
• Speed – Actuates Speed of host vehicle
• Cruise – Actuates Cruise Control of host vehicle
• User Interface
• Warning Indicator – Emergency Messages
• Auto Brake Indicator – ACC Engaged Message

8. ObstacleRadar Sensor
Controller
Brake Actuator
Engine ControlBrakes
Sense Radar Signal
Actuate Brakes
Release Throttle
Brake Signal
Sample Scenario
Auto Brake Indicator
Auto Braking Signal
Throttle ActuatorThrottle

9. Modeling
m s⋅ V s( )⋅ b V s( )⋅+ U s( )
Newton’s Second Law m
dv
dt
⋅ b v t( )⋅+ u t( )
Laplace Transform

10. Block diagram of ACC

11. Proportional control:
G = K.(1/Ts+1).(1/ms+b).(1/s)
T.F K
(Ts+1)(ms+b)(s) + K
Transfer Function

12. Simulation
Solving the transfer function
T.F 26.25
(10s+1)(2000s+150)s+26.25
26.25
20000s2
+ 3500s + 26.25
Linear Simulation for proportional control

13. Step response for a P control
We have performed the T.F modeling and simulation of ACC.
The model is designed for zero overshoot and minimum response
time. The model is simplified with the engine in the block diagram.

14. Controller Design
ddes = h.Vf + ∆ (1)
where,
ddes - desired distance btw vehicles to avoid collision.
V - Host Velocity
h - Time Gap (set by the driver, usu. 1-2.5sec)
∆ - for additional safety (usu. Avg. length of vehicle)

16. Implementation
• Hardware
– Ultra-sonic Distance Meter (UDM)
• Purpose: leading vehicle distance
• Range: 4m
• Accuracy: ± 2.5cm
• Sampling Rate: 1 per sec
– Shaft Encoder (ENC)
• Purpose: Host Velocity
• Resolution: 1 cm per step
– Communication (PC Robot)

17. Brake Actuation
C Air reservoir
Solenoid
valve
Pressure regulator Air cylinder
To brakes
compressor

18. Solenoid Valve Action
5/2 Solenoid valve
5 bar
ON/OFF
Pressure regulator
with gauge
5/2 Solenoid valve Flow control valve
S1 S2
Selector switches
To brakes
Air cylinder

19. Component Details
• Air compressor
 Voltage 12-13.5V
 Max. Current 15A
 Max. pressure 10bar
 Displacement 35L/min
• Air reservoir

20. Pressure regulator
 Max. pressure: 15bar
 Set pressure: 0.5 - 10bar
 Port diameter: ¼”
Pressure gauge
Pressure range: 0-10bar

21. Solenoid valve
 5/2 single solenoid
 Voltage: 12 V
 Power:
 Max. pressure: 10 bar
 Diameter: ¼”

22. Air cylinder
 Double acting
 Bore: 40 mm
 Stroke: 15 mm
 Make: Janatics
 Port diameter: ¼”
 Max. pressure: 10 bar

23.  Flow control valves
 Silencer type
 With lock nut
 Fittings
 Male connector (Dia 6 x ¼”)
 Male elbow (6 x 1/8”)
 Pneumatic line (6 mm dia.)

24. Hardware Details

25. Advantages
• Function properly in poor weather condition
• Conventional Cruise Control operation may be canceled
automatically or by the operator under the following
conditions
 Brake pedal is pressed
 'Off' button is pressed
 Vehicle Speed < 25 mph
 An ACC system fault is detected

26. Further Work
• More experiments to evaluate the design.
• Implementation on a geared 2 wheeler.
• Implementation on a 4 wheeler.
• Modelling with PD & PID controllers.

27. References
• 5th Meeting of the U.S. Software System Safety Working
Group, April 12th-14th 2005 @ Anaheim, California USA
• Petros Ioannou; Cheng-Chih Chien. “Autonomous Intelligent
Cruise Control”. IEEE Trans. On Vehicular Technology,
42(4):657-672, 1993.

28. THANK YOU