Philipp Kremer

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This article accompanies a video that presents a bimanual haptic device composed of two DLR/KUKA Light-Weight Robot (LWR) arms. The LWRs have similar dimensions to human arms, and can be operated in torque and position control mode at an update rate of 1 kHz. The two robots are mounted behind the user, such that the intersecting workspace of the robots and(More)
—In this paper, lossy-compression methods for haptic (velocity and force) data as exchanged in telepresence or virtual reality systems are introduced. Based on the proposed interpolative and extrapolative compression strategies, arbitrary passive compression algorithms can be implemented. The derived algorithms do not affect the stability of the presence(More)
In an ideal case telepresence achieves a state, where a human operator can no longer dierentiate between an interaction with a real environment or a technical mediated one. This state is called transparent telepresence. The applicability of telepresence to on-orbit servicing (OOS), i.e. an unmanned servicing operation in space, teleoperated from ground in(More)
Telepresence systems are often deployed in scenarios where communication bandwidth is limited. Consequently, data exchanged between operator and teleoperator has to be reduced. In case of haptic telepresence, data reduction has an influence on the stability of the overall system. This paper provides a step towards a systematic framework for communication(More)
This article presents a haptic system for bimanual haptic feedback that is composed of two lightweight robot arms. The system has a workspace and force capabilities similar to that of two human arms. Sophisticated control strategies are implemented to enable using this system as haptic interface. Depending on the requirements of the task one of three(More)
Space robots were the topic of this paper. While on earth, nobody would follow such advice; in space, there are few other options than to replace a malfunctioning spacecraft. There are no repair shops and gas stations in the Earth orbit. Because of the lack of so-called on-orbit servicing (OOS) opportunities, some malfunctioning spacecraft continue(More)
This video presents a telepresence system which enables a human operator to explore a remote environment by means of a multimodal man machine interface and rollin' JUSTIN as teleoperator. The man machine interface allows for bimanual, dexterous manipulation and, through two different operating modi of the man machine interface, wide area movement as well. A(More)
Classic telepresence approaches allow a human to interact with a remote or a virtual reality environment (VR) with force feedback. Coupling with a remote robot can be used to work in dangerous environments without the human being on-site. The coupling with a VR system can be used for training and verification of task sequences or robotic
A new lossy compression method is proposed for haptic (force, velocity) data as exchanged in bilateral telepresence systems. The method is based on the passive extrapolative compression strategy proposed in [1]. The innovation is that the extrapolations do not have a stiff horizon, but are triggered by considerable changes (events) in the target(More)
This paper generalizes the Time Domain Passivity Control concept originally introduced by J.-H. Ryu et al. (2004) in order to work for multi-degree of freedom (DoF) haptic systems with time delay. Its energy computation (named passivity observer) factors in the phase shift caused by time delay, and is improved by an energy estimation. Moreover, the variable(More)