Robotic Plug-in Combined Charging System with Improved Robustness

The paper describes development of algorithm robotic plug-in of charging system for mobile platform. In the first chapter, there is short overview of possibilities of automatic plug-in system, include proprietary industrial solution. In the main part, there is a description of system based on UR robot with build-in force torque sensors and Intel RealSense Camera. This camera combines IR depth lens with regular RGB camera and 6 DOF inertial sensor, which is used in our application too.

The conventional solution of this problem is usually based on RGB image processing in various state of art, from simple pattern matching, neural network or genetic algorithm to complex AI solution. The quality of the solution mostly depends on robustness of image processing.

In our cases, we use simple sensor fusion. Thanks to multiple information and constrain of values, we can assume, if algorithm is proceeding successfully or not. The system uses the internal parameters of the robotic arm, e.g. end-effector position and orientation and force-torque information in tool center point. The next information is RGB camera image and camera depth image, and the inertial unit build in camera. The other important information is location of CCS plug on the mobile platform, where the shape of mobile platform is considered as constrain for image processing.

The algorithm is written in Matlab, with support of Intel SDK for camera communication. For Universal Robot control is used TCP-IP communication and multithread program with subroutines and events for robot control is briefly mentioned in the paper too.

The system is validated only on physical model with CCS plug and socket, because the mobile platform is under construction by other team.