Loading...
Search for:
unknown-input-observer
0.006 seconds
Control, Scaling and Stability Analysis of Teleoperated One-Dimensional Micro/Nano-Manipulation Systems
, M.Sc. Thesis Sharif University of Technology ; Ahmadian, Mohammad Taghi (Supervisor) ; Vossoughi, Gholamreza (Supervisor)
Abstract
In this paper, a novel control approach for one-dimensional bilateral teleoperated nanomanipulation system is proposed. While manipulating objects with a nanomanipulator, real time visual feedback is not available. So, force feedback is used to compensate for the lack of visual information. Since nanometer scale forces are dominated by surface forces instead of inertial forces as in macro world, scaling of nanoforces is one of the major issues of teleoperation system. The Hertz elastic contact model is used to model the interactions between the slave robot and the environment. The proposed framework uses the simple proportional derivative control, i.e., the master and slave robots are...
A secure self-synchronized stream cipher
, Article Computer Journal ; Volume 61, Issue 8 , August , 2018 , Pages 1182-1201 ; 00104620 (ISSN) ; Mohebbipoor, F ; Sharif University of Technology
Oxford University Press
2018
Abstract
We follow two main objectives in this article. On the one hand, we introduce a security model called LORBACPA+ for self-synchronized stream ciphers which is stronger than the blockwise LOR-IND-CPA, where we show that standard constructions as delayed CBC or similar existing self-synchronized modes of operation are not secure in this stronger model. Then, on the other hand, following contributions of Millérioux et al., we introduce a new self-synchronized stream cipher and prove its security in LORBACPA+ model. © The British Computer Society 2018. All rights reserved
Adaptive sliding mode control of a piezo-actuated bilateral teleoperated micromanipulation system
, Article Precision Engineering ; Volume 35, Issue 2 , 2011 , Pages 309-317 ; 01416359 (ISSN) ; Ahmadian, M. T ; Vossoughi, G ; Rezaei, S. M ; Zareinejad, M ; Sharif University of Technology
Abstract
Piezoelectric actuators are widely used in micro manipulation applications. However, hysteresis nonlinearity limits the accuracy of these actuators. This paper presents a novel approach for utilizing a piezoelectric nano-stage as the slave manipulator of a teleoperation system based on a sliding mode controller. The Prandtl-Ishlinskii (PI) model is used to model actuator hysteresis in feedforward scheme to cancel out this nonlinearity. The presented approach requires full state and force measurements at both the master and slave sides. Such a system is costly and also difficult to implement. Therefore, sliding mode unknown input observer (UIO) is proposed for full state and force...