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Design of optimised linear quadratic regulator for capsule endoscopes based on artificial bee colony tuning algorithm
摘要： Wireless Capsule Endoscope (WCE) is a new medical device that can be used for examining the whole digestive tract if effectively actuated. In this paper, a new three-coil actuator is proposed for the capsule endoscope navigation system. The proposed system, which is based on the current-controlled magnetic levitation concept, utilises a small permanent magnet within the capsule body and an arrangement of controlled electromagnet actuator placed on a movable frame. The dynamics of the proposed control system is modelled mathematically and then formulated in state space form. In this research, the Linear Quadratic Regulator (LQR) technique is used for designing a 3DOF controller for the capsule actuation system. Artificial Bee Colony (ABC) tuning algorithm is used for obtaining optimum values for controller gain parameters. The optimised LQR controller is simulated by using the Matlab/Simulink tool, and its performance is then evaluated based on the stability and control effort parameters to validate the proposed system. Finally, the simulation results suggest that the LQR controller based on the ABC optimisation method can be adopted to synthesise an effective capsule actuation system.
关键词： electromagnetic actuator,linear quadratic regulator (LQR),wireless capsule endoscope (WCE),artificial bee colony (ABC)
更新于2025-09-23 15:22:29
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A Dual-Mode RF Power Harvesting System With an On-Chip Coil in 180-nm SOI CMOS for Millimeter-Sized Biomedical Implants
摘要： In this paper, we present a dual-mode power harvesting system for millimeter-sized biomedical implants that are immune to the variation of wireless link parameters and loading. The design includes a multistage full-wave voltage rectifier, a power management unit, and a low dropout voltage regulator. Depending on the received RF power level and the required power by the load, power delivery is conducted in a continuous or duty-cycled mode. The system is fabricated in 180-nm silicon on insulator (SOI) CMOS technology with an active area of 2.56 mm2 including an on-chip coil. RF power is transferred to the chip from a 2 × 2 cm2 coil through 10 mm of air at 434 MHz. The efficiency of the designed wireless link, which is the power transfer efficiency from the external coil to the on-chip coil, reaches up to 0.68% (?21.7 dB) at 10-mm separation through air. Keeping the transmitted RF power below 24 dBm, the system can provide a 1.08-V dc voltage for resistive loads larger than 20 kΩ continuously over time. When the harvested power is not enough to drive the load continuously, the system operates in the duty-cycled mode. Measurement results show that the system can drive a 1-kΩ load in the duty-cycled mode when the transmitted power level is 15 dBm.
关键词： voltage rectifier,millimeter-sized implant,power management,on-chip coil,CMOS,rectenna,low dropout (LDO) regulator,wireless power transfer (WPT)
更新于2025-09-23 15:21:21
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LCO-FLL control for single-phase utility integrated single-stage solar PV system
摘要： This study presents a limit cycle oscillator-frequency locked loop (LCO-FLL) control for single-phase utility integrated single-stage photovoltaic (PV) system. The proposed topology increases the utility of the voltage-source converter (VSC), particularly in the absence of PV generation. It has the potential to load harmonics current mitigation. It estimates harmonic free load current accurately with low computational requirement due to the absence of cumbersome mathematical algorithm and transformation techniques. It provides reactive power compensation, both in the absence and the presence of PV generation, improves transient response during dynamics in load and varying irradiance conditions. The total harmonic distortions of utility current and utility voltage, compliance the limit of the IEEE-519 standard. The proportional–integral (PI) regulator regulates the DC-link voltage of VSC input to the reference DC-link voltage. The incremental conductance-based technique derives the reference DC-link voltage. The dynamic behaviour of the LCO-FLL-based control is improved using a feed-forward loop for the PV power sharing. It also reduces loading on the PI controller. Test results demonstrate satisfactory performance of LCO-FLL-based control.
关键词： single-stage solar PV system,LCO-FLL control,proportional–integral (PI) regulator,incremental conductance-based technique,feed-forward loop,reactive power compensation,voltage-source converter (VSC),IEEE-519 standard,single-phase utility
更新于2025-09-23 15:21:21
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Two Beam Initiation Threshold Measurements of Photo-Initiators for Laser Writing of Biocompatible 3D Structures
摘要： This paper presents an independent operation of the rotor-side converter (RSC) and grid-side converter (GSC) for a doubly fed induction generator (DFIG)-based wind energy conversion system under unbalanced grid voltage conditions. In this paper, the RSC is controlled to achieve four different control targets, including balanced stator current, sinusoidal rotor current, smooth stator active and reactive powers, and constant DFIG electromagnetic torque. The GSC is commanded to keep the dc voltage at a constant value. Additional feedback compensators using resonant regulators for the RSC are employed, and the decompositions of the positive and negative sequence components and calculations of the rotor negative current references can be avoided. Another similar compensator is used in the GSC to suppress the dc voltage ?uctuates and remove the GSC reactive power oscillations without the stator or rotor power information. The proposed method can make the RSC and GSC available to an independent operation with a simple implementation for higher reliability. The experimental results demonstrate the effectiveness of the proposed control strategy for both the RSC and GSC under unbalanced grid voltage conditions.
关键词： wind energy conversion system (WECS),resonant regulator,unbalanced grid voltage,independent operation,Doubly fed induction generator (DFIG)
更新于2025-09-23 15:21:01
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[IEEE 2020 IEEE Custom Integrated Circuits Conference (CICC) - Boston, MA, USA (2020.3.22-2020.3.25)] 2020 IEEE Custom Integrated Circuits Conference (CICC) - A Power-Efficient Hybrid Single-Inductor Bipolar-Output DC-DC Converter with Floating Negative Output for AMOLED Displays
摘要： This paper presents a hybrid single-inductor bipolar-output (SIBO) DC-DC converter for active-matrix organic light-emitting diode (AMOLED) displays which are relatively more sensitive to the supply noises on their positive supply. This design significantly improves the display quality by achieving a near-zero voltage ripple at the positive output thanks to the negative output floating and the use of low-power shunt regulators. In addition, with the hybrid topology and the proposed cross-coupled bootstrap-based level-shifter with a dual- PMOS inverter buffer, low-voltage devices without deep-N-well are used, reducing the chip area and cost. The proposed converter is implemented in a 0.35-μm CMOS process with 5-V devices. The targeted output voltages are 5.3V and ?4.7V. Operating at 1MHz, the measured positive output ripple is lower than 1mV in all the conditions. The measured peak power efficiency is 89.3% at 1.1W output power. The maximum output power is 3.5W.
关键词： dual-PMOS inverter,bipolar output,floating negative output,Hybrid converter,shunt regulator,AMOLED display
更新于2025-09-23 15:21:01
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[IEEE 2019 International Conference on Computer, Communication, Chemical, Materials and Electronic Engineering (IC4ME2) - Rajshahi, Bangladesh (2019.7.11-2019.7.12)] 2019 International Conference on Computer, Communication, Chemical, Materials and Electronic Engineering (IC4ME2) - Application of Si-NPs Extracted from the Padma River Sand of Rajshahi in Photovoltaic Cells
摘要： In this study, we propose an auxiliary power regulator (APR) for the current-shared cascade (CSC) structure of the driver stages of RF CMOS power. Although the CSC structure provides a method to reduce the power consumption at the driver stages of a differential power amplifier (PA), it is difficult to obtain optimum levels of effective supply voltage for the first and second driver stages. Additionally, the transistor sizes of the first and second driver stages of the CSC structure must be identical to ensure the proper operation of the PA. Thus, in this work, we propose an APR structure that ensures the proper operation of a PA with different transistor sizes in its first and second driver stages. To prove the feasibility of the proposed technique, we designed the PA with a CSC structure using an APR. From the measured results, we successfully verify the feasibility of the proposed structure. Additionally, we provide experimental results for a typical CMOS PA to determine the optimum supply voltage for the second driver stage.
关键词： efficiency,cascade,supply voltage,Amplifier,regulator
更新于2025-09-23 15:21:01
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Nested control loop design for differential boost inverter using generalized averaged model in photovoltaic applications
摘要： To use photovoltaic energy, voltage source inverters are playing an important role. The most of local AC loads such as AC motors need higher voltage than solar panel output voltage. Differential boost inverter produces an AC voltage that is greater than the DC input voltage in a single power stage. This inverter consists of two DC-DC bilateral boost converters in which work via time-variant duty cycles to produce sinusoidal voltage, and this feature causes complexity in control design. To deal with this complexity, new modeling so-called generalized averaged model is used to achieve a linear time-invariant model. In this paper, a nested control loop is designed. This control strategy consists of two control loops in which the inner loop is designed by linear quadratic regulator theory to displace poles in proper location and the second loop uses a PI-PR controller to track desired voltage and reject disturbances. To evaluate the proposed control method, the sliding mode controller is applied and compared as well. As shown by simulations, the proposed control strategy has more reliable performance and provides higher robustness in comparison with sliding mode control technique in rigid situations such as dealing with nonlinear load, parameters values changes, and external disturbances.
关键词： PI-PR,renewable energies,boost inverter,linear quadratic regulator,generalized averaged model
更新于2025-09-23 15:21:01
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Identification of Master Regulator Genes of UV Response and Their Implications for Skin Carcinogenesis
摘要： Solar UV radiation is a major environmental risk factor for skin cancer. Despite decades of robust and meritorious investigation, our understanding of the mechanisms underlying UV-induced skin carcinogenesis remain incomplete. We previously performed comprehensive transcriptomic profiling in human keratinocytes following exposure to different UV radiation conditions to generate UV-specific gene expression signatures. In this study, we utilized VIPER, a robust systems biology tool, on UV-specific skin cell gene signatures to identify master regulators (MRs) of UV-induced transcriptomic changes. We identified multiple prominent candidate UV MRs, including forkhead box M1 (FOXM1), thyroid hormone receptor interactor 13, and DNA isomerase II alpha, which play important roles in cell cycle regulation and genome stability. MR protein activity was either activated or suppressed by UV in normal keratinocytes. Intriguingly, many of the UV-suppressed MRs were activated in human skin squamous cell carcinomas (SCCs), highlighting their importance in skin cancer development. We further demonstrated that selective inhibition of FOXM1, whose activity was elevated in SCC cells, was detrimental to SCC cell survival. Taken together, our study uncovered novel UV master regulators that can be explored as new therapeutic targets for future skin cancer treatment.
关键词： Keratinocyte,UV signature,skin cancer,master regulator
更新于2025-09-23 15:21:01
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A High Efficiency LCC-S Compensated WPT System with Dual Decoupled Receive Coils and Cascaded PWM Regulator
摘要： A LCC-S compensated wireless power transfer (WPT) system with dual decoupled receive coils and a cascaded PWM regulator is proposed in this paper. The dual decoupled receive coils, comprising of bipolar coil and unipolar coil, provide two power paths. Most of input power is transferred to load directly through bipolar coil while only small portion of input power is transferred through unipolar coil and the cascaded PWM regulator, which can reduce power loss effectively. The output voltage of WPT system is regulated by the cascaded PWM regulator, thereby wireless communication links (WCLs) is not required in the feedback control loop, which leads to simple control circuits and good stability. Compared with conventional WPT system with two-stage power conversion, it is cost-effective as voltage/current stress of PWM regulator can be significantly alleviated. Besides, the LCC-S compensated WPT system can operate under zero phase angle (ZPA) condition with low voltage-ampere rating components. A 1.5kW prototype is built and experimental results show that the system efficiency up to 93% can be achieved under full load, which is 2.3% higher than that of conventional WPT system with two stage power conversion.
关键词： LCC-S compensated WPT system,wireless communication links (WCLs),dual decoupled coil structure,duty cycle control,cascaded PWM regulator
更新于2025-09-23 15:19:57
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Electronic Coordination Effect of the Regulator on Perovskite Crystal Growth and Its High-Performance Solar Cells
摘要： The rapid growth of perovskite crystal leads to excessive grain boundaries and surface defects, which has a negative effect on the performance of solar cells (PSCs). Passivating defects by controlling the crystal growth rate becomes a crucial research hotspot for preparing high crystallinity perovskite films. In this work, phenylacetonitrile (PA) and 2-naphthylacetonitrile (2-NA) served as crystal growth regulators are introduced into the perovskite precursor. The coordination effect of lone-pair electrons (n-electrons) and π-electrons in regulator molecule with Pb2+ on the nucleation and growth of FA0.80MA0.15Cs0.05Pb(I0.85Br0.15)3 perovskite crystal, along with passivation of surface defects and grain boundaries are systematically investigated. The n-electrons of N atom form a coordination bond with Pb2+, and π-electrons in aromatic ring generate a cation-π interaction with Pb2+. This combined effect efficiently delays the crystallization rate of perovskite crystal, and then promotes the grain growth and reduces the grain boundaries, which is favorable for the dissociation of more excitons to carriers. The PA-optimized PSCs show an increasement of PCE from 18.01% to 21.09%, with an unencapsulated device retaining 91.2% of its initial efficiency for 60 days in 40 ± 5% relative humidity under dark condition.
关键词： perovskite solar cells,coordination effect,crystal growth regulator,passivation defects,morphology,cation-π
更新于2025-09-19 17:13:59