Design of a control mode which allows a robotic platform to move while executing a more complex task

Finished: 2019-10-18

Individual assignment

I-botics is an open innovation centre for Research and Development in Interaction Robotics. It is a joint effort between TNO and the University of Twente and is focused on telerobotics and exoskeletons.

Teleoperation is a part of telerobotics which concerns the control of robots by a human from a remote location. The University of Twente is developing one of these teleoperated systems, called the I-botics demonstrator. The system consists of a cockpit and a mobile robot. The cockpit is used to control the mobile robot by capturing the operator’s motions and providing video, audio and haptic feedback to the operator. The mobile robot consists of a robotic platform which can move using omniwheels, and uses a robotic arm with a manipulator to interact with its environment.
Currently, to move the robot platform, bilateral haptic pedals are used. This method uses the steering mechanism as a differential drive, not utilizing the full advantage of the omniwheels. This is useful for driving long distances, but not for accurate repositioning of the platform while the arm is executing a task.

At this time, there is a need for a method to move the robotic platform while performing a more complex task, in order to extend the working range of the manipulator. More specifically, using a method where the end effector is fixed in position, and the motion inputs of the operator are used to move the wheels of the platform, effectively moving the robot. Intuitively, this can be seen by the operator as ‘dragging’ the robot platform around the end effector, which has a fixed position.

The goal of this project is to design and implement a control mode which can be used to move the robot frame while keeping the end effector in a fixed position. This will have the advantages that the platform can be repositioned while the user is executing more complex tasks, extending the range of the manipulator.