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A.j. Kurdila - One of the best experts on this subject based on the ideXlab platform.
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identification of Hysteretic Control influence operators representing smart actuators part ii convergent approximations
Journal of Intelligent Material Systems and Structures, 1997Co-Authors: Harvey Thomas Banks, A.j. Kurdila, G WebbAbstract:In a previous paper, the authors investigated the lower semicontinuity properties of two generalizations of the classical Preisach operator: the smoothed Preisach operator and the Krasnoselskii/Pokrovskii (KP) integral hysteresis operators. In particular, it was demonstrated that the output least squares identification problem for the KP operator is well-posed over compact subsets of the Preisach plane. The identification of the Hysteretic Control influence operator was shown to be equivalent to the identification of a measure in the space of probability measures taken with the weak* topology. In this paper, a consistent and convergent approximation scheme is introduced for this class of integral hysteresis operator. The Galerkin approximation scheme is shown to be function space parameter convergent. A numerical example is presented that illustrates aspects of the theory derived in this paper.
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Compensation for classes of distributed hysteresis operators and representation of active structural systems
35th Aerospace Sciences Meeting and Exhibit, 1997Co-Authors: A.j. Kurdila, G WebbAbstract:A class of integral, Hysteretic Control influence operators are derived for the representation of structural systems exhibiting hysteresis due to active materials. The Hysteretic Control influence operator is defined in terms of a probability distribution, or more generally a measure, that describes the concentration of a particular hysteresis kernel. Two types of hysteresis kernels are studied in detail; the ideal relay kernel leading to a Preisach integral hysteresis operator, and a generalized play kernel leading to a Krasnosel'skii-Pokrovskii operator. When combined with the thermal and structural dynamics equations, the governing equations are history-dependent integropartial differential equations, coupled in a cascade structure. Existence, uniqueness and convergence of Galerkin approximation methods have been derived for the forward simulation and model identification. The cascade structure of the coupled, nonlinear partial differential equations is advantageous in that model reference Control, and model reference adaptive Control strategies, can be derived for the systems under consideration. Numerical and experimental results that validate the theoretical developments in the paper are presented. (Author)
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identification of Hysteretic Control influence operators representing smart actuators part i formulation
Mathematical Problems in Engineering, 1997Co-Authors: Harvey Thomas Banks, A.j. Kurdila, G WebbAbstract:A large class of emerging actuation devices and materials exhibit strong hysteresis characteristics during their routine operation. For example, when piezoceramic actuators are operated under the influence of strong electric fields, it is known that the resulting input–output behavior is Hysteretic. Likewise, when shape memory alloys are resistively heated to induce phase transformations, the input–output response at the structural level is also known to be strongly Hysteretic. This paper investigates the mathematical issues that arise in identifying a class of hysteresis operators that have been employed for modeling both piezoceramic actuation and shape memory alloy actuation. Specifically, the identification of a class of distributed hysteresis operators that arise in the Control influence operator of a class of second order evolution equations is investigated. In Part I of this paper we introduce distributed,Hysteretic Control influence operators derived from smoothed Preisach operators and generalized hysteresis operators derived from results of Krasnoselskii and Pokrovskii. For these classes, the identification problem in which we seek to characterize the Hysteretic Control influence operator can be expressed as an ouput least square minimization over probability measures defined on a compact subset of a closed half-plane. In Part II of this paper, consistent and convergent approximation methods for identification of the measure characterizing the hysteresis are derived.
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Hysteretic Control influence operators representing smart material actuators: identification and approximation
Proceedings of 35th IEEE Conference on Decision and Control, 1996Co-Authors: Harvey Thomas Banks, A.j. KurdilaAbstract:This paper discusses mathematical issues that arise in identifying a class of hysteresis operators that have been employed for modeling shape memory alloy actuation. Specifically, the identifiability of a class of distributed hysteresis operators that arise in the Control influence operator of a class of second order evolution equations is investigated. We introduce distributed, Hysteretic Control influence operators derived from smoothed Preisach operators and generalized hysteresis operators derived from results of Krasnoselskii and Pokrovskii. For these classes, the identification problem in which we seek to characterize the Hysteretic Control influence operator can be expressed as an output least square minimization over probability measures defined on a compact subset of a closed half-plane
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Hysteretic Control influence operators representing smart material actuators: identification and approximation
Proceedings of 35th IEEE Conference on Decision and Control, 1996Co-Authors: Harvey Thomas Banks, A.j. KurdilaAbstract:This paper discusses mathematical issues that arise in identifying a class of hysteresis operators that have been employed for modeling shape memory alloy actuation. Specifically, the identifiability of a class of distributed hysteresis operators that arise in the Control influence operator of a class of second order evolution equations is investigated. We introduce distributed, Hysteretic Control influence operators derived from smoothed Preisach operators and generalized hysteresis operators derived from results of Krasnoselskii and Pokrovskii. For these classes, the identification problem in which we seek to characterize the Hysteretic Control influence operator can be expressed as an output least square minimization over probability measures defined on a compact subset of a closed half-plane.
Harvey Thomas Banks - One of the best experts on this subject based on the ideXlab platform.
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identification of Hysteretic Control influence operators representing smart actuators part ii convergent approximations
Journal of Intelligent Material Systems and Structures, 1997Co-Authors: Harvey Thomas Banks, A.j. Kurdila, G WebbAbstract:In a previous paper, the authors investigated the lower semicontinuity properties of two generalizations of the classical Preisach operator: the smoothed Preisach operator and the Krasnoselskii/Pokrovskii (KP) integral hysteresis operators. In particular, it was demonstrated that the output least squares identification problem for the KP operator is well-posed over compact subsets of the Preisach plane. The identification of the Hysteretic Control influence operator was shown to be equivalent to the identification of a measure in the space of probability measures taken with the weak* topology. In this paper, a consistent and convergent approximation scheme is introduced for this class of integral hysteresis operator. The Galerkin approximation scheme is shown to be function space parameter convergent. A numerical example is presented that illustrates aspects of the theory derived in this paper.
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identification of Hysteretic Control influence operators representing smart actuators part i formulation
Mathematical Problems in Engineering, 1997Co-Authors: Harvey Thomas Banks, A.j. Kurdila, G WebbAbstract:A large class of emerging actuation devices and materials exhibit strong hysteresis characteristics during their routine operation. For example, when piezoceramic actuators are operated under the influence of strong electric fields, it is known that the resulting input–output behavior is Hysteretic. Likewise, when shape memory alloys are resistively heated to induce phase transformations, the input–output response at the structural level is also known to be strongly Hysteretic. This paper investigates the mathematical issues that arise in identifying a class of hysteresis operators that have been employed for modeling both piezoceramic actuation and shape memory alloy actuation. Specifically, the identification of a class of distributed hysteresis operators that arise in the Control influence operator of a class of second order evolution equations is investigated. In Part I of this paper we introduce distributed,Hysteretic Control influence operators derived from smoothed Preisach operators and generalized hysteresis operators derived from results of Krasnoselskii and Pokrovskii. For these classes, the identification problem in which we seek to characterize the Hysteretic Control influence operator can be expressed as an ouput least square minimization over probability measures defined on a compact subset of a closed half-plane. In Part II of this paper, consistent and convergent approximation methods for identification of the measure characterizing the hysteresis are derived.
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Hysteretic Control influence operators representing smart material actuators: identification and approximation
Proceedings of 35th IEEE Conference on Decision and Control, 1996Co-Authors: Harvey Thomas Banks, A.j. KurdilaAbstract:This paper discusses mathematical issues that arise in identifying a class of hysteresis operators that have been employed for modeling shape memory alloy actuation. Specifically, the identifiability of a class of distributed hysteresis operators that arise in the Control influence operator of a class of second order evolution equations is investigated. We introduce distributed, Hysteretic Control influence operators derived from smoothed Preisach operators and generalized hysteresis operators derived from results of Krasnoselskii and Pokrovskii. For these classes, the identification problem in which we seek to characterize the Hysteretic Control influence operator can be expressed as an output least square minimization over probability measures defined on a compact subset of a closed half-plane
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Hysteretic Control influence operators representing smart material actuators: identification and approximation
Proceedings of 35th IEEE Conference on Decision and Control, 1996Co-Authors: Harvey Thomas Banks, A.j. KurdilaAbstract:This paper discusses mathematical issues that arise in identifying a class of hysteresis operators that have been employed for modeling shape memory alloy actuation. Specifically, the identifiability of a class of distributed hysteresis operators that arise in the Control influence operator of a class of second order evolution equations is investigated. We introduce distributed, Hysteretic Control influence operators derived from smoothed Preisach operators and generalized hysteresis operators derived from results of Krasnoselskii and Pokrovskii. For these classes, the identification problem in which we seek to characterize the Hysteretic Control influence operator can be expressed as an output least square minimization over probability measures defined on a compact subset of a closed half-plane.
Liter Siek - One of the best experts on this subject based on the ideXlab platform.
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A Hysteretic Switched-Capacitor DC–DC Converter With Optimal Output Ripple and Fast Transient Response
IEEE Transactions on Very Large Scale Integration Systems, 2017Co-Authors: Zhekai Xiao, Liter SiekAbstract:Hysteretic Control is popular for switched-capacitor (SC) dc–dc converters. Conventional Hysteretic Controllers require either a large output capacitor or high-speed output voltage detection for proper regulation. In this paper, a lower boundary Hysteretic Control method is proposed which matches the output sampling frequency to the converter switching frequency across the entire load range, hence optimal output voltage ripple can be achieved. The converter responses instantly to step-up load transients that are smaller than six times the initial load current. When larger load transient step occurs, the sampling frequency jumps to its maximum value to recover the output voltage quickly. Small output voltage droop can be achieved while using an output capacitance value on the same order as the converter’s charge transferring capacitance. A 1/2 step-down SC dc–dc converter with the proposed Control technique is fabricated in 0.18- $\mu \text{m}$ CMOS process. The converter achieves a peak efficiency of 86.4% and delivers a maximum output power of 5 mW.
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ISIC - Triple boundary multiphase with predictive interleaving technique for switched capacitor DC-DC converter regulation
2014 International Symposium on Integrated Circuits (ISIC), 2014Co-Authors: Zhekai Xiao, Liter SiekAbstract:In this paper, we propose a new technique to regulate multi-phase interleaved switched-capacitor DC-DC converters. Traditionally, SC converters are either regulated by modulating the switching frequencies directly through a voltage-Controlled-oscillator or by using Hysteretic Control where separate Control loops are used for each converter core. Achieving fast regulation by modulating VCO is difficult because it requires a high speed error amplifier and proper loop compensation. Conventional Hysteretic Controller achieves fast regulation, but it uses N comparators or one shared comparator that operates at N times the single phase switching frequency, where N is the level of interleaving. The proposed technique avoids these problems by using triple boundary Hysteretic Control, where one comparator is used for defining the reference voltage, and the other two comparators enable coarse/fine operation to achieve both fast recovery and tight regulation.
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A Fixed-frequency Hysteretic Controlled buck DC-DC converter with improved load regulation
2014 IEEE International Symposium on Circuits and Systems (ISCAS), 2014Co-Authors: Liter Siek, Ravinder Pal Singh, Minkyu JeAbstract:Hysteretic Control is widely adopted in the power management units (PMUs) for modern electronic devices due to their simple and stable Control architecture, as well as the fast load transient response. However, the switching frequency of a traditional Hysteretic converter is not fixed. It changes with operating condition and component aging, and hence brings in electro-magnetic interference (EMI) problems and multiphase interleaving difficulties. In this work, a Hysteretic buck converter with frequency-locking capability is presented, where the switching frequency is adjusted by tuning the Hysteretic window. In addition, the current-mode Hysteretic Control in this work utilizes a simple feedback network, which consists of only passive components and yet provides significant improvement on output voltage regulation. To achieve good reliability at high temperature and high voltage, the proposed buck converter has been fabricated in a 1μm SOI process with a chip area of 6mm2. Experimental results measured at 1MHz fixed switching frequency with 12V-to-5V voltage conversion and 0.9A load current shows a peak efficiency of 91%.
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ISCAS - A Fixed-frequency Hysteretic Controlled buck DC-DC converter with improved load regulation
2014 IEEE International Symposium on Circuits and Systems (ISCAS), 2014Co-Authors: Liter Siek, Ravinder Pal Singh, Minkyu JeAbstract:Hysteretic Control is widely adopted in the power management units (PMUs) for modern electronic devices due to their simple and stable Control architecture, as well as the fast load transient response. However, the switching frequency of a traditional Hysteretic converter is not fixed. It changes with operating condition and component aging, and hence brings in electro-magnetic interference (EMI) problems and multiphase interleaving difficulties. In this work, a Hysteretic buck converter with frequency-locking capability is presented, where the switching frequency is adjusted by tuning the Hysteretic window. In addition, the current-mode Hysteretic Control in this work utilizes a simple feedback network, which consists of only passive components and yet provides significant improvement on output voltage regulation. To achieve good reliability at high temperature and high voltage, the proposed buck converter has been fabricated in a 1μm SOI process with a chip area of 6mm 2 . Experimental results measured at 1MHz fixed switching frequency with 12V-to-5V voltage conversion and 0.9A load current shows a peak efficiency of 91%.
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Triple boundary multiphase with predictive interleaving technique for switched capacitor DC-DC converter regulation
2014 International Symposium on Integrated Circuits (ISIC), 2014Co-Authors: Zhekai Xiao, Liter SiekAbstract:In this paper, we propose a new technique to regulate multi-phase interleaved switched-capacitor DC-DC converters. Traditionally, SC converters are either regulated by modulating the switching frequencies directly through a voltage-Controlled-oscillator or by using Hysteretic Control where separate Control loops are used for each converter core. Achieving fast regulation by modulating VCO is difficult because it requires a high speed error amplifier and proper loop compensation. Conventional Hysteretic Controller achieves fast regulation, but it uses N comparators or one shared comparator that operates at N times the single phase switching frequency, where N is the level of interleaving. The proposed technique avoids these problems by using triple boundary Hysteretic Control, where one comparator is used for defining the reference voltage, and the other two comparators enable coarse/fine operation to achieve both fast recovery and tight regulation.
D. Brian - One of the best experts on this subject based on the ideXlab platform.
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A 10-MHz 14.3W/mm2 DAB Hysteretic Control Power Converter Achieving 2.5W/247ns Full Load Power Flipping and above 80% Efficiency in 99.9% Power Range for 5G IoTs
2019 Symposium on VLSI Circuits, 2019Co-Authors: D. BrianAbstract:A double adaptive bound (DAB) Hysteretic Control power converter is designed for 5G IoTs, which require nanosecond power load flipping and high efficiency across full power range. In response to 1A/3ns load step-up/step-down, it achieves 1% tsettle of 247ns/387ns, thanks to the DAB Control. This is 6× faster than the best of the arts on 0.18μm CMOS. A synchronized DCR offset cancellation scheme improves VO regulation accuracy by 10×. As power scales from full to ultra-light load, the Controller self-reconfigures to remove redundant Controller loss and facilitate adaptive system power delivery. It achieves >80% efficiency over 99.9% of 2.5W full power range. Highly efficient design leads to the highest reported chip power density of 14.3W/mm2.
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VLSI Circuits - A 10-MHz 14.3W/mm 2 DAB Hysteretic Control Power Converter Achieving 2.5W/247ns Full Load Power Flipping and above 80% Efficiency in 99.9% Power Range for 5G IoTs
2019 Symposium on VLSI Circuits, 2019Co-Authors: D. BrianAbstract:A double adaptive bound (DAB) Hysteretic Control power converter is designed for 5G IoTs, which require nanosecond power load flipping and high efficiency across full power range. In response to 1A/3ns load step-up/step-down, it achieves 1% $\mathrm{t}_{settle}$ of 247ns/387ns, thanks to the DAB Control. This is 6× faster than the best of the arts on $0.18 \mu \mathrm{m}$ CMOS. A synchronized DCR offset cancellation scheme improves $V_{O}$ regulation accuracy by 10×. As power scales from full to ultra-light load, the Controller self-reconfigures to remove redundant Controller loss and facilitate adaptive system power delivery. It achieves $\gt80$% efficiency over 99.9% of 2.5W full power range. Highly efficient design leads to the highest reported chip power density of 14.3W/mm2.
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a 25 mhz four phase saw Hysteretic Control dc dc converter with 1 cycle active phase count
IEEE Journal of Solid-state Circuits, 2019Co-Authors: Min Kyu Song, Ashis Maity, D. BrianAbstract:In order to meet stringent power requirements in modern application processors, a 25-MHz four-phase dc–dc power converter is presented. It employs an adaptive window Hysteretic Control to facilitate ultra-fast transient response and minimize output voltage ( $V_{O}$ ) undershoot and overshoot during load transient periods. Inherent clock synchronization ability ensures current balancing between phase sub-converters. The Control also enables a wide range of programmable $V_{O}$ for dynamic voltage/frequency scaling. To maintain high efficiency over a wide power range without degrading transient speed, a 1-cycle active phase count scheme is introduced. A design prototype was fabricated in a 0.35- $\mu \text{m}$ CMOS process with an active die of 1.88 mm2. Simple circuit structure benefits a power density of 3.98 W/mm2. At a switching frequency of 25 MHz and a nominal input of 3.3 V, it regulates a programmable $V_{O}$ ranging from 0.3 to 2.5 V. It achieves more than 80% efficiency over 96.7% of power range with a peak value of 88.1%. In response to 4-A load step-up/down, it achieves 103 mV/123 mV $V_{O}$ undershoot/overshoot with 1% settling time of 190 ns/237 ns, respectively.
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A 25-MHz Four-Phase SAW Hysteretic Control DC–DC Converter With 1-Cycle Active Phase Count
IEEE Journal of Solid-State Circuits, 2019Co-Authors: Min Kyu Song, Ashis Maity, D. BrianAbstract:In order to meet stringent power requirements in modern application processors, a 25-MHz four-phase dc-dc power converter is presented. It employs an adaptive window Hysteretic Control to facilitate ultra-fast transient response and minimize output voltage (VO) undershoot and overshoot during load transient periods. Inherent clock synchronization ability ensures current balancing between phase sub-converters. The Control also enables a wide range of programmable VO for dynamic voltage/frequency scaling. To maintain high efficiency over a wide power range without degrading transient speed, a 1-cycle active phase count scheme is introduced. A design prototype was fabricated in a 0.35-μm CMOS process with an active die of 1.88 mm2. Simple circuit structure benefits a power density of 3.98 W/mm2. At a switching frequency of 25 MHz and a nominal input of 3.3 V, it regulates a programmable VO ranging from 0.3 to 2.5 V. It achieves more than 80% efficiency over 96.7% of power range with a peak value of 88.1%. In response to 4-A load step-up/down, it achieves 103 mV/123 mV VO undershoot/overshoot with 1% settling time of 190 ns/237 ns, respectively.
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A 10MHz, 40V-to-5V clock-synchronized AOT Hysteretic converter with programmable soft start technique for automotive USB chargers
2017 IEEE Applied Power Electronics Conference and Exposition (APEC), 2017Co-Authors: Xugang Ke, D. BrianAbstract:Adaptive on-time (AOT) Hysteretic Control has gained increasing popularity in automotive electronics, because of its superior line regulation and fast load transient response. However, it faces serious switching frequency deviation and soft start issues from the conventional implementations. To mitigate these, this paper proposes a clock-synchronized AOT Hysteretic Control which adaptively synchronizes the switching converter to a desirable reference frequency without degrading its line regulation and load transient response. Meanwhile, a programmable soft start modulator is proposed to allow reliable start-up in heavy load condition and prevent large inrush current from damaging the power devices. Designed on a high voltage (HV) 0.35μm BCD process, the integrated converter achieves a single-stage 40V to 5V voltage conversion with a full load of 15W and a peak efficiency of 90.5%. With the proposed clock-synchronized Ton timer, the switching frequency is maintained at a fixed 10MHz, over the full input, output and load ranges. The programmable soft start modulator achieves 100μs to 6ms soft start time, which greatly suppresses startup inrush current.
Yikai Wang - One of the best experts on this subject based on the ideXlab platform.
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a 450 mv single fuel cell power management unit with switch mode quasi rm v 2 Hysteretic Control and automatic startup on 0 35 mu m standard cmos process
IEEE Journal of Solid-state Circuits, 2012Co-Authors: Yikai WangAbstract:This paper presents a power management unit (PMU) for emerging applications powered by low-voltage single direct methanol fuel cell (DMFC). A subthreshold startup scheme and its circuit implementation are proposed to enable low-voltage self-startup feature. A boost switching converter with a switch-mode, quasi-V2 Hysteretic Control is designed for power conditioning. The PMU is implemented on a standard 0.35-μm CMOS process with VTN/VTP of 0.55 V/ -0.75 V, respectively. Experimental results prove that the PMU automatically starts up with 450-mV single DMFC input. The output voltage of the PMU is well regulated with below 25 mV ripple. With an output power ranging from 20 to 200 mW, an average efficiency above 85.2% is obtained, with a maximum of 89.4%. Load transient recovery times are 11.6 μs/4.2 μs, respectively, in response to the step-up and step-down load changes between 10 and 100 mA.
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A 450-mV Single-Fuel-Cell Power Management Unit With Switch-Mode Quasi-${\rm V}^2$ Hysteretic Control and Automatic Startup on 0.35-$\mu$m Standard CMOS Process
IEEE Journal of Solid-State Circuits, 2012Co-Authors: Yikai WangAbstract:This paper presents a power management unit (PMU) for emerging applications powered by low-voltage single direct methanol fuel cell (DMFC). A subthreshold startup scheme and its circuit implementation are proposed to enable low-voltage self-startup feature. A boost switching converter with a switch-mode, quasi-V2 Hysteretic Control is designed for power conditioning. The PMU is implemented on a standard 0.35-μm CMOS process with VTN/VTP of 0.55 V/ -0.75 V, respectively. Experimental results prove that the PMU automatically starts up with 450-mV single DMFC input. The output voltage of the PMU is well regulated with below 25 mV ripple. With an output power ranging from 20 to 200 mW, an average efficiency above 85.2% is obtained, with a maximum of 89.4%. Load transient recovery times are 11.6 μs/4.2 μs, respectively, in response to the step-up and step-down load changes between 10 and 100 mA.
