Dynamic Obstacle Avoidance

Implementing vision based dynamic obstacle avoidance

Implementing vision based dynamic obstacle avoidance

Project Resources

Why dynamic obstacle avoidance?

Dynamic obstacle avoidance is the process of detecting a region of space that is not navigable (an obstacle), planning a path around it, and executing that plan.

When the obstacle moves, the plan needs to account for the future positions of the object as well, making the process significantly more complicated than passing a static obstacle. 

With this aim, the authors of this project designed and implemented a robust passing algorithm for Duckiebots in Duckietown.

The approach adopted was to develop a new LED-based detection system, modify the typical Duckietown lane following pipeline for planning around the obstacles, and deploying a new controller to execute manoeuvres. 

Dynamic obstacle avoidance:
the challenges

Some of the key challenges associated with this project are the following:

Detection Accuracy: The Duckiebot and Duckies detection systems occasionally produce false positives. Light sources from other Duckiebots or shiny objects can interfere with the LED detection, while yellow line segments can be mistaken for Duckies. Improving the reliability of detection under varying lighting conditions is essential.

Lane Following Stability: The Duckiebots sometimes become unstable while overtaking, especially when driving in the left lane. The lane-following system struggles with large lane pose angles or rapid changes in lane position, which can cause the Duckiebot to veer off the road. Enhancing the lane-following algorithm to maintain stability during lane changes is critical.

Velocity Estimation: Estimating the speed of moving Duckiebots accurately is challenging. The current position data obtained from LED detection fluctuates too much to provide a reliable velocity measurement. Developing a more robust method for estimating the velocity of other Duckiebots is needed to ensure safe and efficient overtaking.

Variable Speed Control: Implementing variable speed control during overtaking is problematic due to instability in the lane-following pipeline when speeds are dynamically adjusted. Adjusting speed based on the detected obstacle’s speed without losing lane stability is difficult, necessitating improvements in the lane control model to handle speed changes effectively.

Project Highlights

Here is the output of their work. Check out the github repository for more details!

Dynamic Obstacle Avoidance: Results

Dynamic Obstacle Avoidance: Authors

Nikolaj Witting is a former Duckietown student of class Autonomous Mobility on Demand at ETH Zurich, and currently works at Trackman as an Algorithm Developer.

Fidel Esquivel Estay is a former Duckietown student of class Autonomous Mobility on Demand at ETH Zurich, currently serving as the Co-Founder at UpCircle.

Johannes Lienhart is a former Duckietown student of class Autonomous Mobility on Demand at ETH Zurich, currently serving as the CTO at Tethys Robotics.

Paula Wulkop is a former Duckietown student of class Autonomous Mobility on Demand at ETH Zurich, where she is currently pursuing her Ph.D.

Learn more

Duckietown is a modular, customizable and state-of-the-art platform for creating and disseminating robotics and AI learning experiences.

It is designed to teach, learn, and do research: from exploring the fundamentals of computer science and automation to pushing the boundaries of knowledge.