323,066 research outputs found
Intrinsically Passive Force Scaling in Haptic Interfaces
Full text linkIn several applications involving haptic interfaces it can be desirable to scale the interaction force perceived by the user. The most intuitive approach is to change the stiffness of the virtual environment but, unfortunately, changing the physical parameters that characterize a virtual environment is a potentially destabilizing action. In this paper we embed in the intrinsically passive haptic scheme recently proposed in S. Stramigioli et al. (2005) a power scaling interconnection that allows to scale the force perceived by the user while preserving the passivity, and consequently the stable behavior, of the overall syste
Sampled Data Systems Passivity and Discrete Port-Hamiltonian Systems
Full text linkIn this paper, we present a novel way to approach the interconnection of a continuous and a discrete time physical system. This is done in a way which preserves passivity of the coupled system independently of the sampling time T. This strategy can be used both in the field of telemanipulation, for the implementation of a passive master/slave system on a digital transmission line with varying time delays and possible loss of packets (e.g., the Internet), and in the field of haptics, where the virtual environment should ‘feel’ like a physical equivalent system.
Compensation of position errors in passivity based teleoperation over packet switched communication networks
Full text linkInvited paper nella sessione intitolata “Putting Energy back in Robotics”
Transparency in Port-Hamiltonian-Based Telemanipulation
Full text linkAfter stability, transparency is themajor issue in the design of a telemanipulation system. In this paper, we exploit the behavioral approach in order to provide an index for the evaluation of transparency in port-Hamiltonian-based teleoperators. Furthermore, we provide a transparency analysis of packet switching scattering-based communication channels
Digital passive geometric telemanipulation
Full text linkIn this paper we present an intrinsically passive telemanipulation scheme over a digital transmission line Internet-like. We present an analysis of the energetic behavior of the communication line both in case of loss of packages and in case of variable delay. The sample data nature of the passive controller is explicitly taken into account following the approach outline
Dealing with Unreliabilities in Digital Passive Geometric Telemanipulation
Full text linkIn this paper two problems arising in the digital passive scheme for telemanipulation presented in are addressed. At first, we show how to preserve system passivity in presence of quantization error introduced by position sensor (i.e. encoders) by introducing energy dissipation. Then, we introduce a scheme for a redundant communication channel that will compensate for missed packets improving performances while preserving passivity of the overall scheme
Variable Delay in Scaled Port-Hamiltonian Telemanipulation
Full text linkIn several applications involving bilateral telemanipulation, master and slave robots act at different power scales (e.g. telesurgery, micromanipulation). Scaling forces and velocities means scaling the power that is exchanged between master and slave sides through the communication channel. In this paper weshow how it is possible to embed power scaling in the scattering based communication channel used in port-Hamiltonian based telemanipulation. Furthermore, a strategy for passively dealing with variable communication delay is proposed in order to allow scaled teleoperation over packet switched networksas Internet
Control of Interactive Robotic Interfaces: a port-Hamiltonian approach
Full text linkThis monograph deals with energy based control of interactive robotic interfaces and the port-Hamiltonian framework is exploited both for modeling and controlling interactive robotic interfaces. Using the port-Hamiltonian framework, it is possible to identify the energetic properties that have to be controlled in order to achieve a desired interactive behavior and it is possible to build a port-Hamiltonian controller that properly regulates the robotic interface by shaping its energetic properties.Thanks to its generality, the port-Hamiltonian formalism allows to model and control also complex interactive robotic interfaces in a very natural way. In this book, a port-Hamiltonian approach for regulating the interaction between a robot and a local environment, a virtual environment (i.e. haptic interfaces) and a remote environment (i.e. bilateral telemanipulation systems) is developed
Port-Based Modeling and Simulation of Mechanical Systems With Rigid and Flexible Links
Full text linkIn this paper, a systematic procedure for the defi- nition of the dynamical model in port-Hamiltonian form of me- chanical systems is presented as the result of the power-conserving interconnection of a set of basic components (rigid bodies, flexible links, and kinematic pairs). Since rigid bodies and flexible links are described within the port-Hamiltonian formalism, their inter- connection is possible once a proper relation between the power- conjugated port variables is deduced. These relations are the anal- ogous of the Kirchhoff laws of circuit theory. From the analysis of a set of oriented graphs that describe the topology of the mecha- nism, an automatic procedure for deriving the dynamical model of a mechanical system is illustrated. The final model is a mixed port- Hamiltonian system, because of the presence of a finite-dimensional subsystem (modeling the rigid bodies) and an infinite-dimensional one (describing the flexible links). Besides facilitating the deduction of the dynamical equations, it is shown how the intrinsic modularity of this approach also simplifies the simulation phase
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