Lidar based obstacle_detection_vishal_mishra
- 1. EMBEDDED RESEARCH PROJECT LIDAR BASED OBSTACLE DETECTION March 2019 – June 2019 Vishal Mishra 1
- 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. 2
- 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 3
- 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) 4
- 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 . 5
- 7. Lidar Interfacing with the Raspberry Pi: 7
- 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 8
- 9. Distance calculation: • Reaction distance: (veh_speed)^2/(20,000 * f) • Braking distance: (veh_speed)^2/(10,000* f) • .f = 0.8 (friction coefficient) 9
- 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. 10
- 12. THANKYOU !! Hochschule RavensburgWeingarten- Master EMM 12