Optimal TCP and Robot Base Placement for Complex Continuous Paths

Project focus

• Computation of the optimal TCP (tool center point) for an industrial robot
• Formulation of an objective function and optimization problem
• Development of a fast underlying path planning algorithm

Description

The robot base placement of an industrial robot w.r.t. to the workpiece is crucial for the execution of a predefined robot motion. This placement is chosen once in the course of planning and constructing the robot work cell. However, in a flexible production environment, the robot trajectories change frequently, and in some cases an expensive and time-consuming repositioning of the robot becomes necessary. This project shows that with small adaptions of the robotic tool, a repositioning of the robot can be avoided.

To this end, an underlying path planning algorithm is developed. This path planner considers wide turning ranges of the robot axes and is capable to plan through kinematic singularities. Based on the path planner, an optimization problem is formulated,  with which the optimal TCP for multiple end-effector paths is determined. The objective function of this optimization problem considers the total number of inverse kinematic solutions, the total number of accomplished solutions, the joint movements and the reserves to the mechanical joint limits. Further, by rephrasing the problem, the proposed optimization algorithm is also capable to derive the optimal robot base position. This work is demonstrated for a trim application in a production line, where an optimal TCP and the optimal robot base position is derived.

Video

Selected Publications

• T. Weingartshofer, C. Hartl-Nesic, and A. Kugi, Optimal TCP and Robot Base Placement for a Set of Complex Continuous Paths, in Proceedings of the International Conference on Robotics and Automation (ICRA), Xi’an, China, 2021, pp. 9659-9665.
  [BibTex]

  @InProceedings{Weingartshofer2021,
  author = {Weingartshofer, T. and Hartl-Nesic, C. and Kugi, A.},
  booktitle = {Proceedings of the International Conference on Robotics and Automation (ICRA)},
  title = {Optimal TCP and Robot Base Placement for a Set of Complex Continuous Paths},
  doi = {10.1109/ICRA48506.2021.9561900},
  pages = {9659 - 9665},
  address = {Xi'an, China},
  issn = {2577-087X},
  month = {5},
  year = {2021},
  }