Robot Arm Tracking with Random Decision Forests




For grasping and manipulation with robot arms, knowing the current pose of the arm is crucial for successful controlling its motion. Often, pose estimations can be acquired from encoders inside the arm, but they can have significant inaccuracy which makes the use of additional techniques necessary. In this master thesis, a novel approach of robot arm pose estimation is presented, that works on single depth images without the need of prior foreground segmentation or other preprocessing steps. A random regression forest is used, which is trained only on synthetically generated data. The approach improves former work by Bohg et al. by considerably reducing the computational effort both at training and test time. The forest in the new method directly estimates the desired joint angles while in the former approach, the forest casts 3D position votes for the joints, which then have to be clustered and fed into an iterative inverse kinematic process to finally get the joint angles. To improve the estimation accuracy, the standard training objective of the forest training is replaced by a specialized function that makes use of a model-dependent distance metric, called DISP. Experimental results show that the specialized objective indeed improves pose estimation and it is shown that the method, despite of being trained on synthetic data only, is able to provide reasonable estimations for real data at test time.

Author(s): Felix Widmaier
Year: 2015
Month: May

Department(s): Autonomous Motion
Research Project(s): Robot Arm Pose Estimation as a Learning Problem
Bibtex Type: Thesis (mastersthesis)

School: Eberhard-Karls-Universität Tübingen

Language: English
Attachments: PDF


  title = {Robot Arm Tracking with Random Decision Forests},
  author = {Widmaier, Felix},
  school = {Eberhard-Karls-Universität Tübingen},
  month = may,
  year = {2015},
  month_numeric = {5}