Observer (physics)
Related papers: 20
About
An observer, in the context of physics and control systems, is a mathematical construct or algorithmic module that estimates the internal states of a dynamic system from available measurements—typically inputs and outputs—when direct measurement of all states is impractical or impossible. In robotics and AI, observers are fundamental building blocks used to reconstruct unmeasured quantities such as joint velocities, external disturbances, sensor faults, or attitude orientation. Common examples include disturbance observers (which estimate and compensate for unmodeled forces acting on manipulators), extended state observers (which treat unknown nonlinearities as augmented system states), sliding mode observers (used for robust fault reconstruction), and nonlinear attitude observers for orientation estimation from inertial sensors. Observers also underpin visual servoing architectures and multi-agent coordination by providing filtered, reliable state information to controllers. Their importance lies in enabling high-performance, robust control without requiring expensive or fragile sensor suites—allowing a controller to react to conditions it cannot directly measure. Stability guarantees for observer designs are typically established using Lyapunov theory, making them analytically grounded tools that bridge theoretical dynamical systems analysis with practical engineering implementation.
Top Researchers
Jean-Jacques Slotine
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Oussama Khatib
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Amjad J. Humaidi
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Ayad Q. Al-Dujaili
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J.-C. Latombe
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Daniela Rus
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Jean‐Claude Latombe
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Steven M. LaValle
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Hugh Durrant‐Whyte
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Wolfram Burgard
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Top Institutes
Top Cited Papers
A nonlinear disturbance observer for robotic manipulators
Wen‐Hua Chen, D.J. Ballance, P.J. Gawthrop, J. O’Reilly
Citations: 1710 • 2000
Nonlinear Complementary Filters on the Special Orthogonal Group
Robert Mahony, Tarek Hamel, Jean-Michel Pflimlin
Citations: 1686 • 2008
Disturbance Observer Based Control for Nonlinear Systems
Wen‐Hua Chen
Citations: 1423 • 2004
Dynamic sensor-based control of robots with visual feedback
L.E. Weiss, Arthur C. Sanderson, Charles P. Neuman
Citations: 822 • 1987
Relative end-effector control using Cartesian position based visual servoing
W.J. Wilson, Carol Hulls, Gregory Bell
Citations: 621 • 1996
Cooperative Control of Multi-Agent Systems: Optimal and Adaptive Design Approaches
Frank L. Lewis, Hongwei Zhang, Kristian Hengster‐Movric, Abhijit Das
Citations: 602 • 2013
Nonlinear robust fault reconstruction and estimation using a sliding mode observer
Xing‐Gang Yan, Christopher Edwards
Citations: 557 • 2007
Extended State Observer-Based Integral Sliding Mode Control for an Underwater Robot With Unknown Disturbances and Uncertain Nonlinearities
Rongxin Cui, Lepeng Chen, Chenguang Yang, Mou Chen
Citations: 551 • 2017
Extended-State-Observer-Based Control of Flexible-Joint System With Experimental Validation
S. E. Talole, Jaywant P. Kolhe, S. B. Phadke
Citations: 500 • 2009
Observer design for a class of nonlinear systems
S Vijaya Raghavan, J. Karl Hedrick
Citations: 492 • 1994
Stable adaptive observers for nonlinear time-varying systems
Georges Bastin, M. Gevers
Citations: 477 • 1988
Nonlinear disturbance observer design for robotic manipulators
Alireza Mohammadi, Mahdi Tavakoli, Horacio J. Marquez, Farzad Hashemzadeh
Citations: 466 • 2012
A passivity approach to controller-observer design for robots
H. Berghuis, Henk Nijmeijer
Citations: 434 • 1993
Robot control by using only joint position measurements
S. Nicosia, P. Tomei
Citations: 420 • 1990
A portable three-dimensional LIDAR-based system for long-term and wide-area people behavior measurement
Kenji Koide, Jun Miura, Emanuele Menegatti
Citations: 405 • 2019
Attitude control without angular velocity measurement: a passivity approach
Fernando Lizarralde, John T. Wen
Citations: 402 • 1996
Modeling of Force Sensing and Validation of Disturbance Observer for Force Control
Seiichiro Katsura, Yuichi Matsumoto, Kouhei Ohnishi
Citations: 399 • 2007
Neural Network Control of a Robotic Manipulator With Input Deadzone and Output Constraint
Wei He, David Ofosu Amoateng, Zhao Yin, Changyin Sun
Citations: 396 • 2015
Vibration Control of a Flexible Robotic Manipulator in the Presence of Input Deadzone
Wei He, Yuncheng Ouyang, Jie Hong
Citations: 385 • 2016
Unknown Input Observer Based Robust Fault Estimation for Systems Corrupted by Partially-Decoupled Disturbances
Zhiwei Gao, Xiaoxu Liu, Michael Chen
Citations: 372 • 2015