Project Description
As systems such as robotic manipulators or mobile robots are naturally described by their dynamics, it stands to reason to not only model them in terms of differential equations of second order but also to govern them using force control. This provides the opportunity to fulfill tasks that cannot be solved using position or velocity control techniques, especially in problems where the robot is in contact with the corresponding workpiece, e.g., when pushing objects or in haptic problems. Moreover, explicitly governing the interacting forces can lead to significant improvements regarding the safety of the manipulator and the workpiece. However, explicitly controlling the force introduces novel challenges with respect to the controller and the design of the end-effector. In order to obtain precise models, models following from first order methods can be combined with data-driven approaches.
In order to solve force control tasks within the field of mobile robotics, some of the institute's omnidirectional mobile robots have been equipped with a tailored force-sensing unit. This sensor enables the robots to explicitly measure the interaction force between the mobile robot and an object such that the robots are capable of precisely governing the overall acting force on the object. By using findings from cooperative robotics swarms , one obtains a functioning scheme that can transport a large class of rigid objects along arbitrary paths.
Current research questions include the extension of the derived concepts regarding formation finding and control approaches to the manipulation and transportation of highly flexible objects, e.g., when transporting a thin sheet by attaching multiple mobile robots and explicitly controlling the interaction forces between the robots and the object. Moreover, the tailored force-sensing unit designed in-house can be utilized to measure and control the interaction force at a robotic manipulator's tool center point with a workpiece.