The project demonstrates the use case: Lidar based obstacle detection for Autonomous driving.

1. EMBEDDED RESEARCH PROJECT
LIDAR BASED OBSTACLE DETECTION
March 2019 – June 2019
Vishal Mishra
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2. Introduction:
• Behavior of vehicle is determined by Lidar Laser Readings.
• Depending on speed and steering angle , obstacle detection is determined by the
vehicle.
• Two thresholds zones are defined by the system. First is warning and the second is
emergency breaking zone.
• The extremities of zone is dependent upon the vehicle speed. For example : if
vehicle is moving at a lower speed, nearby obstacles are detected and if the
vehicle is moving at a higher speed , far distance obstacles are also detected.
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3. Challenges :
• XV11 Lidar Interfacing with Raspberry Pi on ROS platform
• Processing the XV11 laser data into an understandable format.
• Determination of DynamicWarning and Emergency Zones ranges depending on
Vehicle Speed
• Development of Motor Control Unit for RC model Car
• Developing a complete Dynamic System on ROS platform
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4. Vehicle Control Planning:
• Check the lidar data for obstacle in your field of view
• Depending on speed, direction of the car and especially on the steering angle,
decide whether or not the object blocks your vehicle
• Provide two thresholds: t1 for warning distance, t2 for emergency break assist
• If the distance above is lower than t1, set a warning signal (e.g. yellow light or low
beep)
• If the distance above is lower than t2, set an emergency break signal (e.g. yellow
light or low beep) (the signal can be used by the steering project above)
• Test and validate on RC model car (either simple warning signal or in combination
with the steering project above)
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5. Software Development:
• Define the all regions for obstacle detection by LIDAR sensor “ front, fright, fleft, left,
back, bleft, bright
• Get speed , Angle and direction from topic published by steering team
• Based on speed and friction coefficient will find threshold values for warning and
emergency brake signal.
• Based on direction detect obstacles only in that direction.
• Based on steering angle, detect obstacles in that range
• Once the vehicle is in warning zone, publish reduced speed values to steering team and
glow aYELLOW LED indicating an approaching obstacle.
• Once the vehicle is in emergency zone, publish Zero speed value to steering team for
emergency brake and glow the RED LED .
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6. Software Development Flowchart :
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7. Lidar Interfacing with the Raspberry Pi:
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8. RC car motor-
control circuit:
• This setup is used to control the motor
of the wheels of RC model car.
• When the vehicle approaches the
obstacle in the breaking zone, this
circuit is used to bring the car at rest.
• Reference :
https://business.tutsplus.com/de/tutori
als/controlling-dc-motors-using-
python-with-a-raspberry-pi--cms-
20051
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9. Distance
calculation:
• Reaction distance:
(veh_speed)^2/(20,000 * f)
• Braking distance:
(veh_speed)^2/(10,000* f)
• .f = 0.8 (friction coefficient)
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10. Results:
• Obstacle Detection based on direction
and steering angle.
• Warning Signal is provided if vehicle
enters in warning zone limit.
• Speed values are linearly reduced and
published to steering team.
• Zero Speed values are provided when
vehicle enters emergency zone.
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11. SampleVideo:
Hochschule RavensburgWeingarten- Master EMM 11

12. THANKYOU !!
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