Driver error is the most common cause of traffic
India contributes 6 % of the world's road accident
Cell phones in-car ,entertainment systems, more traffic
and more complicated road systems making it more
Drowsiness of the driver and failure in taking sudden
decisions adds up to the factors .
The fully autonomous cars posses the technology which
drives it the safest way possible and have been proved
successful in this context till now .
What is a driverless car ?
As the name says , this car does not need a driver to
drive it .
The passenger just has to feed in the destinations he
want to reach and the car will take him to the
We can compare this with the “Autopilot” system we are
familiar of . The difference here is that , the autopilot
system just make the vehicle move in a predefined path
or a straight path , but this system drives the vehicle
through any roads of varying traffic density and
topography , in the safest way .
About existing driverless cars..
A lot of experiments where done regarding this topic but the
only successful , fully autonomous , driverless car was finally
invented by a team of engineers in Google .
Google Chauffer or Google Car is considered to be one of the
best inventions in the last 25 years .
Consisting of a whole lot of sensor systems and a powerful
central processing unit , Google Car easily drives through any
traffic conditions and topologies .
It detects pedestrians , cyclists , traffic signals , oncoming
vehicles , speed and distance to be maintained between
successive vehicles etc .
Making the car driverless..
The systems used in the car are : LIDAR( Light Detection And Ranging)
Automotive Radar System
GPS( Global Positioning System)
Inertial Measurement Unit
A central processing unit or computer unit to control all the
above systems as well as systems like ABS (Antilock Braking
System) , ESC ( Electronic Stability Control ) , Self Parking etc.
The LIDAR System
The Light Detection And Ranging system can be considered as the eye of the
It is a remote sensing technology which measures distance by illuminating a
target with a light beam and analyses the reflected light .
It uses Laser beams , ultra violet , visible light or near infrared light to image
It can target a wide range of materials .
Here , a narrow laser beam is used , which maps physical structures with a
high resolution .
There are two types of LIDAR systems : Coherent and Incoherent .
Here , a Coherent LIDAR system is used which uses Optical Heterodyne
Detection , which yields more sensitivity than Incoherent systems , but at the
expense of more complex transceiver components .
The LIDAR System…..
The system uses Laser beams of wavelength 1550 nm which are “ eye-safe”.
The scanning module used here is a Velodyne 64 beam laser module .
The basic LIDAR system consists of a Laser
range finder beam reflected using a rotating
The laser beam is scanned around the scene
to be digitized , in 3 Dimensions using an array
of similar systems , gathering distance measures
at specified angle intervals .
The detector part uses two main technologies
i.e, Solid State Photo detectors and Photomultipliers.
The LIDAR sensors require info about their orientation and position , which
they obtain from the GPS and the Inertial Measurement Unit .
The Automotive Radar System
The Radar system used here is of 24GHz domain which have good
performance in range and azimuth angle measurement .
The range of radar systems used is up to 300m .
The radar system are used for detecting oncoming vehicles , their speed , other
obstacles , for self parking , blind spot detection , pre-crash detection etc.
The Radar systems are installed on the bumper of the vehicle at the front
as well as at the back side of the vehicle .
For applications other than blind spot
detection , higher precision , longer range and
higher update rates are needed .
Radar systems detect the surrounding
environment and the central computer combines
this result with that of the LIDAR system .
The Automotive Radar System…..
The Radar system is mounted in the above way . The sensor IF-output signals
are processed separately in the DSP control units and four target lists are sent
to the central processor (radar decision unit) via CAN bus.
Each single sensor measures the target range only. The data fusion is
performed in the radar decision unit.
The Application part means the unit to which the information gained is to be
The information include distance information of objects , relative velocities of
objects and their angular positions .
How the car sees the world
The information from the LIDAR system , the Radar Systems as well as The
ULTRASONIC Sensors which are used for Blind Spot detection as well as to
detect nearby objects and also some data from the video camera are
combined by the central processing unit .
By combining these data , a 3D map of the surroundings is generated by the
central computer .
The 3D map will include detailed info.
about moving and stationary objects , like
pedestrians , cyclists , other vehicles , edges
of roads .
Combining the 3D map with info. from
the GPS module , the central processing
unit controls the steering , accelerator
The Video Camera
Video cameras are installed at the top of the front glass of the near the rear
These cameras are used to detect the traffic lights , traffic signs , pedestrians
The traffic lights are detected by image processing which is done by the
central processing computer.
The computer processes the videos and detects whether traffic lights are red ,
yellow or green .
If a red/yellow light is detected , the computer stops/slows down the vehicle .
The Video Cameras also detect different
road signs like “ STOP” signs , ZEBRA
crossings , sign Boards etc .
The GPS and IMU Systems
GPS ( Global Positioning System ) , uses satellites to gather information about
the current position of the vehicle , the topology and by using the GPS a map
of the area is loaded into the central computer .
But data from GPS alone is less accurate . So , this data is combined with
outputs from the IMU ( Inertial Measurement Unit ) .
IMU is an electronic device which measures and gives information about the
vehicle’s velocity , orientation , gravitational forces etc.
IMU uses a combination of accelerometers , gyroscopes and magnetometers .
An IMU helps GPS system to work when signals are unavailable such as in
tunnels , buildings , bad weather conditions and when electromagnetic
interference is present .
By combining data from IMU-GPS systems , a map is developed and is
compared with the 3D map prepared by the computer for better results .
This system is also used in navigating the car by the user in which the
passenger gives the destination he needs to reach using GPS systems .
The Central Computer
All the data obtained from each and every sensor systems is fed to the central
The central computer is a very powerful processing unit mounted on the inside
of the vehicle .
Position Estimator Sensor is an important part of the vehicle , which is an
ultrasonic sensor used to detect the current position of the vehicle and respond
to even a small movement of the vehicle .
It is used for constantly updating the position of the vehicle with respect to the
3D map .
It is mounted near the left rear wheel .
The central computer constantly receives data from the position estimator
( also called Wheel Encoder ) and combines it with the data from the other
The computer uses this data to control the steering , accelerator , brakes etc .
The computer also helps in navigating to a desired point through the shortest
It is also used for limiting the speed of the vehicle .
Other Technologies Used In The Car
Electronic stability control
Lane Departure Warning
Automated Guided Vehicle
Automotive Night Vision
Managing traffic flow to increase road capacity.
Relieving vehicle occupants from driving allowing them to
concentrate on other tasks or to rest during their journeys.
To avoid accidents .
Increasing roadway capacity by managing the distances
The current location of vehicle can be determine using
global positioning system (G.P.S) .
If the vehicle is using internet which is have less
security then From the hackers point of view in
some cases the vehicle can be switched off on the
road(in rare cases)
Hackers can change the rout which is plotted in the
system(in rare cases)
In case of failure of main sensor and backup sensors
the vehicle can create a chance of accident
Also , there is difficulty for the system to understand
The driver less car is a technological masterpiece.
It is boon for handicapped people and for those who feel
uncomfortable while driving .
It is very helpful in reducing the number of accidents .
The high cost of the sensor systems is a factor which can
adversely affect it . But mass production of the vehicle
can reduce the effect .
Also , if the nations like India approve such cars to be
driven in the traffic , it will be very much helpful for us .