ep48 - Romeo Ortega: From sliding modes to adaptive, passivity-based and energy-shaping control

inControl

inControl
ep48 - Romeo Ortega: From sliding modes to adaptive, passivity-based and energy-shaping control
Sep 13, 2026 Season 4 Episode 10
Alberto Padoan

Outline
00:00 - Intro
01:31 - Mexico City to Leningrad: a communist girlfriend, and a year of Russian
05:40 - Sliding modes at the source
10:38 - France: Ioan Landau, Laurent Praly, and dynamic normalization
16:25 - Continuity, robustness, and the Rohrs counterexamples
24:18 - On Gerhard Kreisselmeier
28:04 - Illinois and Mexico
35:31 - Mark Spong, Twente, and passivity-based control
46:32 - Energy shaping, damping injection, and total energy shaping
49:50 - IDA-PBC, written on a napkin in a Paris café
58:09 - Putting Energy Back in Control, Slotine, and the dissipation obstacle
1:02:50 - Where good problems come from: knock on the practitioners' door
1:06:23 - Immersion and invariance
1:13:40 - Power shaping, Brayton and Moser, and shifted passivity
1:19:29 - Power systems and going back to Russia
1:27:23 - DREM: the adjugate trick that decouples parameter estimation
1:31:11 - Sensorless observers
1:34:44 - A seminar in Yakubovich's flat and on data-driven control
1:41:47 - Advice to the next generation
1:44:43 - Outro

Links
Romeo Ortega's website: https://facultad.itam.mx/facultad/romeo-ortega-martinez
Utkin, "Variable structure systems with sliding modes": https://doi.org/10.1109/TAC.1977.1101446
Variable structure systems with chattering reduction: https://doi.org/10.1016/0005-1098(84)90076-1
Robustness of discrete-time direct adaptive controllers (dynamic normalization): https://doi.org/10.1109/TAC.1985.1103890
Robustness of adaptive controllers, a survey: https://doi.org/10.1016/0005-1098(89)90023-X
Comments on the robust stability analysis of adaptive controllers using normalizations: https://doi.org/10.1109/9.28033
Feuer & Morse, "Adaptive control of single-input single-output linear systems": https://doi.org/10.1109/TAC.1978.1101822
Rohrs, Valavani, Athans & Stein, "Robustness of continuous-time adaptive control algorithms in the presence of unmodeled dynamics": https://doi.org/10.1109/TAC.1985.1104070
Åström's commentary on the Rohrs et al. paper: https://doi.org/10.1109/TAC.1985.1104066
Hsu & Costa, "Bursting phenomena in continuous-time adaptive systems with a sigma-modification": https://doi.org/10.1109/TAC.1987.1104440
Karafyllis & Krstić, "Robust Adaptive Control: Deadzone-Adapted Disturbance Suppression": https://doi.org/10.1137/1.9781611978438
Discrete-time model reference adaptive control using generalized sampled-data hold functions: https://doi.org/10.1109/9.50351
Kreisselmeier, "The generation of adaptive law structures for globally convergent adaptive observers": https://doi.org/10.1109/TAC.1979.1102066
Gao, Bosso, Wang, Saussié & Yi, "Input-output data-driven stabilization of continuous-time linear MIMO systems": https://arxiv.org/abs/2511.06524
Adaptive motion control of rigid robots, a tutorial (where "passivity-based control" is coined): https://doi.org/10.1016/0005-1098(89)90054-X
Takegaki & Arimoto, "A new feedback method for dynamic control of manipulators": https://doi.org/10.1115/1.3139651
Torque regulation of induction motors: https://doi.org/10.1016/0005-1098(93)90059-3
Passivity-based Control of Euler-Lagrange Systems: https://doi.org/10.1007/978-1-4471-3603-3
PID Passivity-Based Control of Nonlinear Systems with Applications: https://doi.org/10.1002/9781119694199
PID passivity-based control of port-Hamiltonian systems (all passive outputs): https://doi.org/10.1109/TAC.2017.2732283
Energy-shaping of port-controlled Hamiltonian systems by interconnection: https://doi.org/10.1109/CDC.1999.830260
Interconnection and damping assignment passivity-based control of port-controlled Hamiltonian systems (IFAC High Impact Paper Award 2026): https://doi.org/10.1016/S0005-1098(01)00278-3
Putting energy back in control: https://doi.org/10.1109/37.915398
Slotine, "Putting physics in control": https://doi.org/10.1109/37.9164
Chang, Bloch, Leonard, Marsden & Woolsey, "The equivalence of controlled Lagrangian and controlled Hamiltonian systems": https://doi.org/10.1051/cocv:2002045
The matching conditions of controlled Lagrangians and IDA-passivity based control: https://doi.org/10.1080/00207170210135939
Control by interconnection and standard passivity-based control of port-Hamiltonian systems: https://doi.org/10.1109/TAC.2008.2006930
Ferguson & Borja, "Control-by-interconnection beyond Casimirs and connections to IDA-PBC": https://doi.org/10.1109/TAC.2026.3661486
Immersion and invariance, a new tool for stabilization and adaptive control of nonlinear systems: https://doi.org/10.1109/TAC.2003.809820
Nonlinear and Adaptive Control with Applications: https://doi.org/10.1007/978-1-84800-066-7
Brayton & Moser, "A theory of nonlinear networks I": https://doi.org/10.1090/qam/169746
Power shaping, a new paradigm for stabilization of nonlinear RLC circuits: https://doi.org/10.1109/TAC.2003.817918
Passivity of nonlinear incremental systems: https://doi.org/10.1016/j.sysconle.2007.03.011
Interconnection and damping assignment approach to control of PM synchronous motors: https://doi.org/10.1109/87.960344
An energy-shaping approach to the design of excitation control of synchronous generators: https://doi.org/10.1016/S0005-1098(02)00177-2
Transient stabilization of multimachine power systems with nontrivial transfer conductances: https://doi.org/10.1109/TAC.2004.840477
Conditions for stability of droop-controlled inverter-based microgrids: https://doi.org/10.1016/j.automatica.2014.08.009
A parameter estimation approach to state observation of nonlinear systems (PEBO): https://doi.org/10.1016/j.sysconle.2015.09.008
Performance enhancement of parameter estimators via dynamic regressor extension and mixing (DREM): https://doi.org/10.1109/TAC.2016.2614889
On modified parameter estimators for identification and adaptive control: https://doi.org/10.1016/j.arcontrol.2020.06.002
Generalized parameter estimation-based observers (GPEBO): https://doi.org/10.1016/j.automatica.2021.109635
Sensorless control of surface-mount permanent-magnet synchronous motors: https://doi.org/10.1109/TPEL.2009.2025276
A globally exponentially convergent sensorless observer for the IPMSM: https://doi.org/10.1016/j.automatica.2025.112138
Willems, "The behavioral approach to open and interconnected systems": https://doi.org/10.1109/MCS.2007.906923
Abramovich, Kuznetsov & Leonov, "V. A. Yakubovich, mathematician, father of the field": https://doi.org/10.1016/j.ifacol.2015.09.150

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Acknowledgments and sponsors
This episode was supported by the National Centre of Competence in Research on «Dependable, ubiquitous automation» and the IFAC Activity fund. The podcast benefits from the help of an incredibly talented and passionate team. Special thanks to L. Seward, E. Cahard, F. Banis, F. Dörfler, J. Lygeros, ETH studio and mirrorlake . Music was composed by A New Element.

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