World Champion in the RoboCup Logistics League 2015 in China

We won Robocup 2015 in the Logistics League with the Carologistics Team! Although there were many major and challenging changes of the league, we could defend our title as world champion. In the finals we won against Team Solidus with the score 56:26.

After arriving in Hefei, China, and getting introduced to the Chinese culture, we entered an exiting RoboCup competition. This years main challenge in the Logistics League was to adapt to the almost completely changed competition area and game rules. In contrast to last year, the game has changed from a moderately difficult and more abstract production scenario to a more realistic, flexible and plausible production scenario with actual processing stations based on the Festo Modular Production System (MPS). Especially finding the randomly placed machines and handling their small tolerances in the production were difficult tasks. We could build on top of our basic success at the RoboCup German Open and further improved our system to solve the challenge.

In the exploration phase of the game our robots explored the factory environment to find randomly placed machines. They used our flexible collision avoidance and navigation to drive to possible machine-positions in the unknown environment. To find machines we detected lines in the laser range data to cope with random machine orientation and determined the type and exact machine position by looking for attached AR tags. During the exploration, the robots dynamically generated a navigation-graph which is used later in the production. By presenting this approach based on Voronoi and CGAL we won a technical challenge.

In the production phase we struggled at the start of the tournament because of small tolerances when placing workpieces on the conveyor belt of a machine. Later in the tournament our machine handling improved. Here we benefited from our idea to adjust the height of the gripper by detecting the conveyor belt with OpenCV. To coordinate the multi-robot team and to perform the reasoning about the world model and the actions to take, we used a CLIPS agent based on the Incremental Task-Level Reasoning approach. The agent was adapted to the new game to control the new exploration phase, reason about the new machine types, their instruction, production preparation and output. Furthermore, the agent needed to handle random product orders with designated delivery times and a wide variety of product types and complexity.

Another factor for our success at the RoboCup is the simulation of the RCLL based on Gazebo. After modelling the new game and our robots in the simulation, we could use it for rapid prototyping and testing during the development. This was especially useful in the development of the agent and the low level behavior. It also allowed us to test before the RoboCup without having a full competition field.

After solving these challenging tasks to achieve a successful exploration and production, we won the finals against Team Solidus with the score 56:26. However, we are eager to improve our performance further. Now that we have a successful basis to explore, handle and reason about the new machines, we can focus on more efficient task allocation, faster physical interaction and more ideas to improve.

Posted by Frederik Zwilling on July 22, 2015 13:00

Tags: league logistics robocup


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