Autonomous Object Retrieval with a Robotic Arm!!

Samantha Luber, Zach Oligschlaeger, John Scheible!

Abstract!Through incorporating various object detection algorithms on images from an overhead camera, we are able to efficiently track balls and blocks in the robotic arm’s search space. By applying a planning algorithm, the robotic arm is able to retrieve reachable objects and move them to the collection bin. !

Ball Detection!•  Optimized template matching

algorithm scans through images from overhead camera!

•  Searches for balls using a stored yellow ball image as the template!

Block Detection!•  Uses a Union Find algorithm

to build up pixel blobs of the same color!

•  Determines blobs within a color and size threshold to be blocks!

•  Calculates block orientation with respect to the arm!

Planning!•  Detects reachable objects!•  Calculates movement

required by each joint needed to reach object and plans joint movement to avoid collisions!

•  Detects if the object was missed and re-attempts retrieval if necessary!

•  Moves object to static goal location!

Arm Communication!•  LCM message passing by subscribing and

posting movement commands to each servo’s channel!