Piero Triverio

The Department of Electrical and Computer Engineering in the Stephen J. R. Smith Faculty of Engineering and Applied Science at Queen's University welcomes applications from outstanding established scholars in the area of Artificial Intelligence and Exascale Computing. The Canada Excellence Research Chairs (CERC) program awards world-renowned researchers and their teams $8 million or $4 million over 8 years to lead ambitious research programs in areas that align with the Government of Canada’s Science, Technology and Innovation (ST&I) priority areas.

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PROPORTIONAL-INTEGRAL-FILTER LINEAR-QUADRATIC REGULATOR (PIF-LQR) In analyzing electrical networks, HENDRIK BODE identified desirable frequency response characteristics for single-input/single-output (SISO) systems. For a unity feedback system, the open-loop transfer function should have high gain at low frequency and low gain at high frequency. The logarithm of the amplitude ratio should have a slope of -20 dB/dec in the vicinity of the CROSSOVER FREQUENCY, where the amplitude ratio is one and its logarithm is zero. This provides good low-frequency tracking, good high-frequency noise rejection, and reasonable tolerance of parameter variations. LQRs can be designed to satisfy Bode's conditions for MULTIVARIABLE SYSTEMS. Although basic LQRs often provide comparable multivariable (MIMO) characteristics, the desired high gain at low frequency and low gain at high frequency is ENFORCED by using proportional-integral-filter (PIF) compensation. PIF compensation introduces integrals and low-pass filters in the control system structure. Gains are computed by the MATLAB instruction [C,S,E] = lqr(F,G,Q,R,M). CLOSED-LOOP STABILITY meets LQR stability guarantees for linear, time-invariant (LTI) systems when they satisfy criteria described in the references. DIGITAL-ADAPTIVE PIF-LQRs have been demonstrated in FLIGHT TESTS of NASA's VALT (Vertical Takeoff and Landing Technology) CH-47 helicopter. "The flight tests have verified the digital controller design procedure, as well as the autotrim and the Type 1 features of the longitudinal controller predicted by theory." (Downing and Bryant) References  . Section 6.3, Cost Functions and Controller Structures, Optimal Control and Estimation, https://lnkd.in/enHjaWtp. . Lecture 11, Linear-Quadratic Control System Design, Optimal Control and Estimation, https://lnkd.in/eXm44EH4. . Section 8.2, Linear-Quadratic Optimal Control, Flight Dynamics, https://lnkd.in/ePctugN8. . Stengel, R., Broussard, J., and Berry, P., Digital Flight Control Design for a Tandem-Rotor Helicopter, https://lnkd.in/eS2FWiMM . Downing, D., and Bryant, W., Flight Test of a Digital Controller Used in a Helicopter Autoland System, https://lnkd.in/et44EarX

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I gave a keynote on grid tied energy storage for the IEEE Smart Energy Grid Engineering Conference (SEGE) at Ontario Tech University earlier this week. In preparing the talk, I was surprised to find out just how far things have come in the grid tied storage area. A lot of the things we've dreamed about in the battery area are really happening in a big way now: 33 GW of utility scale battery energy storage are online in the US as of this month, virtual power plants through aggregation of home energy storage are making a big impact (535 MW of coordinated generation from 100,000 home battery systems was demoed in California at the end of July), and vehicle charging is now increasingly being coordinated through demand response programs with utilities to minimize the impact on the grid. More details can be found in my presentation: https://lnkd.in/gXt6Z-a2 This all bodes well for the continued growth of renewables on the grid. Let's hope the positive momentum (and the positive economics of renewable sources) will keep things going.

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At #APEC2025, we are excited to present a high-efficiency, isolated piezoelectric transformer (PT) that enables acoustically-isolated power conversion with no magnetic components. Piezoelectric components are promising future passive components for power conversion - unlike magnetics, they scale favorably to small sizes. In recent years, single-port piezoelectric resonators have demonstrated efficiencies of >99% and power handling densities of >5 kW/cm^3. However, piezoelectric transformers have historically seen significantly lower efficiencies and orders of magnitude lower power densities without compensating magnetics (efficiencies for magnetic-less dc-dc converters based on isolated PTs have been in the 70-80% range at best). Our most recent prototype of this work, designed by Sourav Naval, Wentao Xu, and Mustapha Touhami, has demonstrated a peak power stage efficiency of >98%. Come see Sourav’s talk on Wednesday at 4:40pm in A301 (Resonant Converters session) to learn more! We are very grateful for Enphase Energy’s support of this work - Michael Harrison, Donald Zimmanck, and Sophia Chou - via the Berkeley Power and Energy Center (https://bpec.berkeley.edu/) #APEC2025 #BPEC #UCBerkeley #powerelectronics #piezoelectrictransformers

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The 2025 Active Silicon Photonics Fabrication Workshop Queen's University brought together a dynamic cohort of researchers, engineers, and students for an intensive, hands-on experience in photonic integrated circuit (PIC) design, simulation, fabrication, and testing. With expert instruction from leading Canadian universities and support from industry partners like Siemens , Ansys (Lumerical), and Luceda Photonics, participants gained invaluable skills and access to cutting-edge tools and fabrication technologies. This year's workshop also featured the NUCLEUS symposium, bridging AI and quantum computing with photonics, further enriching the learning experience. This event showcases the collaborative spirit and innovation driving Canada’s semiconductor ecosystem forward. FABrIC’s wide-ranging support for skills development includes micro-credentialing, intensive hands-on training, Technology for Non-Techies (TNT) and knowledge-sharing webinars. https://loom.ly/B3q1syY

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