DORA - Dexterous Robot Assistant Autonomous door opening with a mobile manipulator

Abstract

Abstract This thesis has focused on building a ROS based system for autonomous door detection and opening using a mobile manipulator. The mobile manipulator in question, DORA (Dexterous Robot Assistant), is based on the MiR200 mobile platform along with an UR10 robotic arm. The robot is equipped with an Intel realsense D435i depth camera. DORA had a navigation system and motion planning system for the arm already implemented and these systems were used in the process of this project. Object detection was achieved through a YOLO algorithm on the image stream from the depth camera, and pose estimation was done using the depth values obtained. The program was tested and found to be consistent and accurate when the robot was located in front of the door, but becomes unreliable in edge cases when the door is located at the edge of the field of vision or on an angle. The door opening program creates a trajectory for opening a door with unknown kinematics and an uncertain hinge location by utilizing readings from a force/torque sensor that is located between the arm and the end-effector, and the position of said end-effector. By employing the MoveIt framework, DORA was able to follow that trajectory and successfully open the door. Testing has confirmed that the force/torque sensor enables the program to operate successfully even in the presence of a 16% error in the estimation of the placement of the hinge position. In conclusion it has been determined that although further development in safety systems and increased versatility is required for real world use, a solid foundation for further work has still been created in this thesis and the capabilities of DORA to interact with the world has been greatly expanded.