AUTOMATICSPEED CONTROLLED CAR
AUTOMATIONFOR SAFETY
Submittedto
Md. Hasibul Alam
Lecturer, Departmentof EEE, BUET
Submittedby
0906166, 0906167, 0906168, 0906169,
0906170, 0906171, 0906172, 0806027
OBJECTIVE:
• To design a car which will detect speed breakers and large
obstacles and control its speed accordingly to avoid
damages.
COMPONENTS:
• 2 Ultrasonic Sensors (HC- SR04)
• 1 ATMEGA32A
• 1 L293D Motor Driver
• Switches
• Resistors
COMPONENTS:
HC- SR04
• 2 sensors are used
• Includes ultrasonic transmitter, receiver and control circuit
• Upper one for large obstacles
• Lower one for speed breakers
COMPONENTS:
HC- SR04
Wiring connections
• 5V VCC
• Trigger Pulse Input
• Echo Pulse Output
• Ground
COMPONENTS:
HC- SR04
The basic principle of work of HC - SR04 :
• Using IO trigger for at least 10us high level signal,
• The Module automatically sends eight 40 kHz and detect whether there is a pulse
signal back.
• IF the signal back, through high level , time of high output IO duration is the time
from sending ultrasonic to returning. Test distance (in meters)= (high level time ×
velocity of sound (340M/S) /2
•Distance in inches = Time / 148
OPERATION:
Speed Breakers:
• If a car running at V m/s detects a speed breaker 2 feets away,
it reduces its speed to V/2 m/s
• When the distance is 1 feet, its speed reduces to V/4 m/s
OPERATION:
Speed Breakers:
• After crossing, the speed again increases to V m/s
OPERATION:
Large Obstacles:
• If a large obstacle is detected, the car stops at 6 inches distance
CIRCUIT DIAGRAM:
Upper
Sensor
Lower
Sensor
LIMITAIONS AND SAFETY:
• L293D is heat sensitive, so operation can be hampered in case
of large power drop
• Heat sink should be used in whole system
ADVANTAGES:
• Security from damages
• Attractive for Electric Propulsion Motors
• Effective in highly populated areas
• Applicable for carrying goods in hospitals, industries, spaceships
etc.
• Important feature for vehicles used for collecting informations
in areas men cannot reach
FUTURE APPLICATIONS:
• Addition of wi-fi device to communicate with other cars around
to avoid collisions
• Addition of direction change systems
THANK YOU

Automatic Speed Controlled Car