A new boundary force is proposed to solve rigid body interaction in SPH (Smoothed Particle Hydrodynamics). The new boundary force is impulse-based rather than potential-based. The impulse is converted to a boundary force with a fundamental observation that the impulse is a momentum change which is a result of a force acting on an object during a time interval. Our new impulse-based boundary for...

Contour tracking control is one of the fundamental operations for robotic systems. In this paper, a position domain PD control is developed to control a multi-DOF nonlinear robotic system for improving contour tracking performance. In this new position domain control system, a robotic system is viewed as a master–slave system where the master motion is used as an independent reference through e...

The simulation of the store separation using the automatic coupling of dynamic equations with flow aerodynamics is addressed. The precision and cost (calculation time) were considered as comparators. The method used in the present research decreased the calculation cost while limiting the solution error within a specific and tolerable interval. The methods applied to model the aerodynamic force...

In this article we introduce a fast iterative solver for sparse matrices arising from the finite element discretization of elliptic PDEs. The solver uses a fast direct multi-frontal solver as a preconditioner to a simple fixed point iterative scheme. This approach combines the advantages of direct and iterative schemes to arrive at a fast, robust and accurate solver. We will show that this solv...

In this article, we present a control framework for reactive mobile manipulation of robotic systems with a large number of actuated degrees of freedom (DOF). We apply the concept to the humanoid robot Rollin’ Justin of the German Aerospace Center (DLR). As service robotics is expected to be established in households and human environments in the near future, we consider relevant aspects like sa...

Distances to multiple targets are measured simultaneously using a single femtosecond pulse laser split through a diffractive optical element. Pulse arrival from each target is detected by means of balanced cross-correlation of second harmonics generated using a PPKTP crystal. Time-of-flight of each returning pulse is counted by dual-comb interferometry with 0.01 ps timing resolution at a 2 kHz ...

In bilateral teleoperation of a dexterous task, to take full advantage of the human’s intelligence, experience, and sensory inputs, a possibility is to engage multiple human arms through multiple masters (haptic devices) in controlling a single slave robot with high degrees-of-freedom (DOF); the total DOFs of the masters will be equal to the DOFs of the slave. A multi-master/single-slave cooper...