An adaptive cruise control system for cars is presented. The system uses an ultrasonic distance sensor and microcontroller to automatically control the speed of the host vehicle based on the distance to the vehicle ahead. It maintains a safe distance without driver intervention. The system alerts the driver if the vehicle needs to slow down or speed up to maintain the safe distance. It was designed to avoid accidents and alert drivers to speed limits to enable safe travel.

1. AN ADAPTIVE
CRUISE CONTROL SYSTEM
IN A CAR
Presented By:
Komal Shinde
Guided By:
Prof. S. S. Agrawal

2. Introduction
 Cruise control - automatically controls the speed of
a motor vehicle.
 Also known as speed control or auto cruise.
 Adjusting the throttle position to maintain a speed
set by the driver

3. Block Diagram for ACC

4.  Microcontroller: 8bit PIC microcontroller acts as the
brain of the system.
 Display: LCD Display acting as the dashboard display
for the driver to operate the system
 Ultrasonic distance sensor : Sense the front vehicle gap
 DC Motor: Wheels are attached with this motor
 Switches: used to switch on the Adaptive Cruise Control
system by the driver.

5. Necessity of RTOS
 The need of having Real time operating systems is
multitasking
 RTOS kernel Codes are written mostly in C
and its portable

6. Working

7. Algorithm
 Step 1: Consider three cars on the highway and the host car
associated with Adaptive Cruise Control.
 Step 2: Assign vehicle id for each car.
 Step 3: Calculate the distance between each cars and assign safety
distance.
 Step 4: Measure the speed of each cars.
 Step 5: Track the cars speed along with safety distance and take
necessary actions.
 Step 6: Indicate the suitable flash message on the dash board
 Step 7: If the car is about cross safety limits, alert the driver to
switch from ACC mode to normal mode.
 Step 8: If the car ahead is slow and host car’s speed has to be
slowed down this is indicated by clockwise rotation of stepper
motor.
 Step 9: If the car behind is fast and host car’s speed has to be
increased, this is indicated by anti-clockwise rotation of stepper
motor.

8. Top view of Prototype Front view of Prototype

9. Features
 Maintains a safe, comfortable distance between vehicles
without driver interventions
 Maintains a consistent performance in poor visibility
conditions.
 Maintains a continuous performance during road turns
and elevation changes
 Alerts drivers by way of automatic braking.

10. Advantages
 It’s very useful for long driving.
 The driver is relieved from the task of careful
acceleration, deceleration and braking in congested
traffics.
 Can avoid unconsciously violating speed limits.
 Reduction in accident rate.
 Reduction in driver fatigue.
 Increased fuel efficiency.

11. Disadvantages
 Cost
 Not for heavy traffic
 Dangerous in slippery roads
 Encourages the driver to become careless.
 The ACC systems not respond directly to the traffic
signals.

12. Conclusion
 Adaptive cruise control (ACC) is an effective method
employed and utilized by vehicles while on long drive.
 ACC helps the driver to relax himself while on long
drive and the journey is smoothened.
 The proposed system mainly designed in order to avoid
accidents and to alert the drivers about the speed limits
for safe traveling.