pdf files of the selected papers shown below are available upon request.

Please send e-mail to khalil@msu.edu

High-gain Observers (basic theory)

- F. Esfandiari and H.K. Khalil. Output feedback stabilization of fully linearizable systems. Int. J. Control, vol. 56, 1007-1037, 1992.
- H.K. Khalil and F. Esfandiari. Semiglobal stabilization of a class of nonlinear systems using output feedback. IEEE Trans. Automat. Contr., vol. 38, 1412-1415, 1993.
- S. Oh and H.K. Khalil. Output feedback stabilization using variable structure control. Int. J. Control, vol. 62, 831-848, 1995.
- S. Oh and H.K. Khalil. Nonlinear output feedback tracking using high-gain observer and variable structure control. Automatica, vol. 33, 1845-1856, 1997.
- A.N. Atassi and H.K. Khalil. A separation principle for the stabilization of a class of nonlinear systems. IEEE Trans. Automat. Contr., vol. 44, 1672-1687, 1999.
- A.N. Atassi and H.K. Khalil. Separation results for the stabilization of nonlinear systems using different high-gain observer designs. Systems & Control Letters, vol. 39, 183-191, 2000.
- A.N. Atassi and H.K. Khalil. A separation principle for the control of a class of nonlinear systems. IEEE Trans. Automat. Contr., vol. 46, 742-746, 2001.
- H.K. Khalil and L. Praly. High-gain observers in nonlinear feedback control. Int. J. Robust and Nonlinear Control, vol. 24, 993-1015, 2014.
- H.K. Khalil. Cascade high-gain observers in output feedback control. Automatica, vol. 80, 110-118, 2017.
- H.K. Khalil. High-gain observers in feedback control: application to permanent magnet synchronous motors. IEEE Control Systems Magazine, vol. 37, 25-41, 2017.

·
H. Liu and H.K. Khalil.**
**Output
feedback stabilization using super-twisting control and high-gain observer. Int.
J. Robust and Nonlinear Control, vol. 29, 601—617, 2019.

High-gain Observers (discrete-time implementation)

- A. Dabroom and H.K. Khalil. Discrete-time implementation of high-gain observers for numerical differentiation. Int. J. Control, vol. 72, 1523-1537, 1999.
- A.M. Dabroom and H.K. Khalil. Output feedback sampled-data control of nonlinear systems using high-gain observers, IEEE Trans. Automat. Contr., vol. 46, 1712-1725, 2001.

High-gain Observers (unmodeled dynamics)

- R.W. Aldhaheri and H.K. Khalil. Effect of unmodeled dynamics on output feedback stabilization of nonlinear systems. Automatica, vol. 32, 1323-1327, 1996.
- M.S. Mahmoud and H.K. Khalil. Robustness of high-gain observer-based nonlinear controllers to unmodeled actuators and sensors. Automatica, vol. 38, 361-369, 2002.
- H.K. Khalil. A note on the robustness of high-gain-observer-based controllers to unmodeled actuator and sensor dynamics. Automatica, vol. 41, 1821--1824, 2005.

High-gain observer (time delay)

· J. Lei and H.K. Khalil. High-gain-predictor-based output feedback control for time-delay nonlinear systems. Automatica, vol. 71, 324-333, 2016.

· J. Lei and H.K. Khalil. Feedback linearization for nonlinear systems with time-varying input and output delays by using high-gain predictor. IEEE Trans. Automat. Contr., vol. 61, 2262-2268, 2016.

High-Gain Observers (effect of measurement noise)

- L.K. Vasiljevic and H.K. Khalil. Error bounds in differentiation of noisy signals by high-gain observers. Systems \& Control Letters, vol. 57, 856--862, 2008.
- J. Ahrens and H.K. Khalil. High-gain observers in the presence of measurement noise: {A} switched-gain approach. Automatica, vol. 45, 2009.
- H.K. Khalil. Analysis of sampled-data high-gain observers in the presence of measurement noise. European Journal Of Control, 2009.
- A.A. Prasov and H.K. Khalil. A nonlinear high-gain observer for systems with measurement noise in a feedback control framework. IEEE Trans. Automat. Contr., vol. 58, 569-580, 2013.
- A.A. Prasov and H.K. Khalil. Tracking performance of a high-gain-observer in the presence of measurement noise. Int. J. Adaptive Control and Signal Processing, vol. 30, 1228-1243, 2016.

Extended High-Gain Observers

- L.B. Freidovich and H.K. Khalil. Performance recovery of feedback-linearization-based designs. IEEE Trans. Automat. Contr., vol. 53, 2324--2334, 2008.
- M.S. Nazrulla and H.K. Khalil. Robust stabilization of non-minimum phase nonlinear systems using extended high gain observers. IEEE Trans. Automat. Contr., vol. 56, 802--813, 2011.
- K. Ma, H.K. Khalil, Y. Yao. Guidance law implementation with performance recovery using an extended high-gain observer. Aerospace Science and Technology, vol. 24, 177-186, 2013.

· J. Lee, R. Mukherjee, and H.K. Khalil. Output feedback performance recovery in the presence of uncertainties. Systems & Control Letters, vol. 90, 31-37, 2016.

· H.K. Khalil. Extended high-gain observers as disturbance estimators. SICE Journal of Control, Measurement, and System Integration, vol. 10, 125--134, 2017.

· A.M. Boker and H.K. Khalil. Semi-global output feedback stabilization of non-minimum phase nonlinear systems. IEEE Trans. Automat. Contr., vol. 62, 4005--4010, 2017.

·
Y. Wu, A. Isidori, R. Lu,
and H.K. Khalil. Performance recovery of dynamic feedback-linearization
methods for multivariable nonlinear systems. IEEE Trans. Automat.
Contr., vol. 65, 1365—1380, 2020.

Adaptive Control of Nonlinear Systems

- H.K. Khalil. Adaptive output feedback control of nonlinear systems represented by input-output models, IEEE Trans. Automat. Contr., vol. 41, 177-188, 1996.
- K.W. Lee and H.K. Khalil. Adaptive output feedback control of robot manipulators using high-gain observers. Int. J. Control, vol. 67, 869-886, 1997.
- B. Aloliwi and H.K. Khalil. Adaptive output feedback regulation of a class of nonlinear systems: convergence and robustness. IEEE Trans. Automat. Contr., vol. 42, 1714-1716, 1997.
- B. Aloliwi and H.K. Khalil. Robust adaptive output feedback control of nonlinear systems without persistence of excitation. Automatica, vol. 33, 2025-2032, 1997.

Adaptive Control Using Neural Networks

- F.-C. Chen and H.K. Khalil. Adaptive control of nonlinear systems using neural networks. Int. J. Control, vol. 55, 1299-1317, 1992.
- F.-C. Chen and H.K. Khalil. Adaptive control of a class of nonlinear discrete-time systems using neural networks. IEEE Trans. Automat. Contr., vol. 40, 791-801, 1995.
- S. Seshagiri and H.K. Khalil. Output feedback control of nonlinear systems using RBF neural networks. IEEE Trans. on Neural Networks, vol. 11, 69-79, 2000.

Logic-based Switching

- L.B. Freidovich and H.K. Khalil. Logic-based witching for robust control of minimum phase nonlinear systems. Systems & Control Letters, vol. 54, 713-727, 2005.

- L.B. Freidovich and H.K. Khalil. Lyapunov-based switching control of nonlinear systems using high-gain observers. Automatica, vol. 43, 150-157, 2007.

Nonlinear Sampled-data Control

- H.K. Khalil. Performance recovery under output feedback sampled-data stabilization of a class of nonlinear systems. IEEE Trans. Automat. Contr., vol. 49, 2173-2184, 2004.
- J.H. Ahrens and X. Tan and H.K. Khalil. Multirate sampled-data output feedback control with application to smart material actuated systems. IEEE Trans. Automat. Contr., vol. 54, 2009.

Extended Kalman Filter

- J. Ahrens and H.K. Khalil. Closed-loop behavior of a class of nonlinear systems under EKF-based control. IEEE Trans. Automat. Contr., vol. 52, 536-540, 2007
- A.M.A. Boker and H.K. Khalil. Nonlinear observers comprising high-gain observers and Extended Kalman Filters. Automatica, vol. 49, 3583-3590, 2013.

Nonlinear Integral Control

- N. Mahmoud and H.K. Khalil. Asymptotic regulation of minimum phase nonlinear systems using output feedback. IEEE Trans. Automat. Contr., vol. 41, 1402-1412, 1996.
- H.K. Khalil. Universal integral controllers for minimum phase nonlinear systems. IEEE Trans. Automat. Contr., vol. 45, 490-494, 2000.
- H.S. Kay and H.K. Khalil. Universal integral controllers with non-linear integral gains. Int. J. Control, vol. 17, 1521-1531, 2004.
- S. Seshagiri and H.K. Khalil. Robust output feedback regulation of minimum-phase nonlinear systems using conditional integrators. Automatica, vol. 41, 43-54, 2005.
- A. Singh and H.K. Khalil. Regulation of nonlinear systems using conditional integrators. Int. J. Robust and Nonlinear Control, vol. 15, 339-362, 2005.
- X. Huang, H.K. Khalil, and Y. Song. Regulation of nonminimum-phase nonlinear systems using slow integrators and high-gain feedback. IEEE Trans. Automat. Contr., vol. 64, 640—653, 2019.

Nonlinear Regulation (Servomechanisms)

- H.K. Khalil. Robust servomechanism output feedback controllers for feedback linearizable systems. Automatica, vol. 30, 1587-1599, 1994.
- N. Mahmoud and H.K. Khalil. Robust control for a nonlinear servomechanism problem. Int. J. Control, vol. 66, 779-802, 1997.
- H.K. Khalil. On the design of robust servomechanisms for minimum phase nonlinear systems. Int. J. Robust and Nonlinear Control, vol. 10, 339-361, 2000.
- S. Seshagiri and H.K. Khalil. Robust output regulation of minimum phase nonlinear systems using conditional servocompensators. Int. J. Robust and Nonlinear Control, vol. 15, 83-102, 2005.
- K. Ma and H.K. Khalil. On the Transient Response of a Nonlinear Output Regulator. IEEE Trans. Automat. Contr., vol. 55, 1455--1460, 2010.
- A.Y. Memon and H.K. Khalil. Output regulation of nonlinear systems using conditional servocompensators. Automatica, vol. 46, 1119--1128, 2010.
- R. Li and H.K. Khalil. Nonlinear output regulation with adaptive conditional servocompensator. Automatica, vol. 48, 2550-2559, 2012.
- R. Li and H.K. Khalil. On the steady-state error of a nonlinear regulator. Int. J. Robust and Nonlinear Control, vol. 23, 1869--1879, 2013.

Funnel Control

· D. Chowdhury and H.K. Khalil. Funnel control for nonlinear systems with
arbitrary relative degree using high-gain observers. Automatica, vol. 105, 107—116,
2019.

Multi-agent Systems

· D. Chowdhury and H.K. Khalil. Fast consensus in multi-agent systems with star topology using high gain observers. IEEE Control Systems Letters, vol. 1, 188-193, 2017.

·
D. Chowdhury and H.K.
Khalil. Practical
synchronization in networks of nonlinear heterogeneous agents with application
to power systems. IEEE Trans. Automat. Contr., Early access, 2020.

·
D. Chowdhury and H.K.
Khalil. Scalable
consensus in networks of multi-agent systems using high-gain observers. IEEE
Trans. Control Network Sys., Early access, 2020.

Control of Induction Motors

- H.K. Khalil and E.G. Strangas. Robust speed control of induction motors using position and current measurements. IEEE Trans. Automat. Contr., vol. 41, 1216-1220, 1996.
- E.G. Strangas, H.K. Khalil, B. Aloliwi, L. Laubinger, and J. Miller. Robust tracking controllers for induction motors without rot or position sensor: analysis and experimental results. IEEE Trans. on Energy Conversion, vol. 14, 1448-1458, 1999.
- B. Aloliwi, H.K. Khalil, and E.G. Strangas. Robust speed control of induction motors: application to a benchmark example. Int. J. Adaptive Control and Signal Processing, vol. 14, 157-170, 2000.
- H.K. Khalil and E.G. Strangas and S. Jurkovic. Speed observer and reduced nonlinear model for sensorless control of induction motors. IEEE Trans. Contr. Sys.Tech., vol. 17, 327--339, 2009.

Feedback Control of Singularly Perturbed Systems

- H.K. Khalil. Output feedback control of linear two-time-scale systems. IEEE Trans. Automat. Contr., AC-32, 784-792, 1987.
- H.K. Khalil and F.-C. Chen. H-infinity control of two-time-scale systems, Systems & Control Letters, vol. 19, 35-42, 1992.
- M. Djemai, J.P. Barbot, and H.K. Khalil. Digital multi-rate control for a class of nonlinear singularly perturbed systems. Int. J. Control, vol. 72, 851-865, 1999.
- S.-L.Chen, S.W. Shaw, H.K. Khalil, and A.W. Troesch. Robust stabilization of large amplitude ship rolling in beam seas. J. of Dyn. Sys., Meas., and Contr., 122, 108-113, 2000.

Nanopositioning and Systems with Hysteresis

- A. Esbrook, X. Tan, and H.K. Khalil. Control of systems with hysteresis via servocompensation and its application to nanopositioning. IEEE Trans. Contr. Sys. Tech., vol. 21, 725--738, 2013.
- A. Esbrook, X. Tan, and H.K. Khalil. An indirect adaptive servocompensator for signals of unknown frequencies with application to nanopositioning. Automatica, vol. 49, 2006--2016, 2013.
- M. Edardar, X. Tan, and H.K. Khalil. Tracking error analysis for feedback systems with hysteresis inversion and fast linear dynamics. J. of Dyn. Sys., Meas., and Contr., 136, 2014.
- A. Esbrook, X. Tan, and H.K. Khalil. Inversion-free stabilization and regulation of systems with hysteresis via integral action. Automatica, vol. 50, 1017-1025, 2014.
- A. Esbrook, X. Tan, and H.K. Khalil. Self-excited limit cycles in an integral-controlled system with backlash. IEEE Trans. Automat. Contr., vol. 59, 1020-1025, 2014.
- M. Edardar, X. Tan, and H.K. Khalil. Design and analysis of sliding mode controller under approximate hysteresis compensation. IEEE Trans. Contr. Sys. Tech., vol. 23, 598-608, 2015.

Mechanical Systems

· J. Lee, R. Mukherjee, and H.K. Khalil. Output feedback stabilization of inverted pendulum on a cart in the presence of uncertainties. Automatica, vol. 54, 146-157, 2015.

· R. Jafari, F.B. Mathis, R. Mukherjee and H. Khalil. Enlarging the region of attraction of equilibria of underactuated systems using impulsive inputs. IEEE Trans. Contr. Sys. Tech., vol. 24, 334-340, 2016.

·
N. Kant, R. Mukherjee, D.
Chowdhury, and H.K. Khalil. Estimation of the region of attraction of underactuated
systems and its enlargement using impulsive inputs. IEEE Trans. Robotics, vol.
35, 618—632, 2019.