The three-dimensional (3-D) vibration-assisted turning (VAT) has attracted increasing attention for its merits in microstructure sculpturing and ultraprecision machining. However, most current 3-D VAT tools adopt complex structures and it is still difficult to implement high frequency and large amplitude simultaneously on a simple integrated tool. In this article, a 3-D VAT tool with high frequency

In this article, a converter-based multibus dc microgrid (MG) in series is studied, in which the tradeoff between voltage recovery and current equalization has been a hot topic of interest. To solve this problem, a distributed learning-based high-order fully actuated (DL-HOFA) secondary control is proposed in this article, and the simple structure of this control technique facilitates its application

Cogging torque (CT) would cause the vibration and noise of the permanent magnet homopolar inductor machine (PMHIM), which should be suppressed. However, the unipolar air-gap flux density and the dual-segment stator and rotor cores of PMHIM make the characteristics of CT unclear, which leads to a lack of theoretical basis for suppressing the CT. Addressing this issue, the CT of PMHIM is investigated

Conventional switched reluctance motors (SRMs) face challenges like low torque density and high noise. To overcome these challenges, the structure of SRMs can be modified. This article introduces a new hybrid-excited 16/18 two-phase SRM with a C-core structure. Each pole of the C-core has two teeth, which develop a positive torque during the rotor rotation; this enhances the torque and torque density

The optimal operation of complicated industrial processes is mainly reflected in the optimization of objective functions, such as product quality and energy consumption. The conventional use of the mean-value of objective function is difficult to describe all the information of the optimized objective when the system is subjected to random uncertainties. In this article, the probability density function

The underwater propulsion system (UPS) with two counter-rotating propellers is very popular now. In tradition, it needs two electric machines or additional gears, which greatly increases the volume and weight of the system. Therefore, a novel counter-rotating axial-flux permanent magnet (AFPM) machine based on magnetic-field modulation (MFM) for the UPS is proposed. It contains a more pole rotor and

At present, insulated-gate bipolar transistor (IGBT) is widely used as the converter component in the submodule of modular multilevel converter (MMC) for its excellent performance in driving circuit and switching speed, but the further application is restricted by its high conduction loss and cost rate. Integrated gate-commutated thyristor (IGCT) is another converter device used in MMC with low conduction

This article presents a new bipolar step-up dc/dc converter with the capability of decreasing the input current ripple for renewable energy applications. Two power switches with the simultaneous operation are used in the proposed converter. The suggested topology can provide positive and negative output voltages in a quadratic form with the same and different voltage levels and common ground. The bipolar

The electronic throttle system (ETS) is one of the important components of an automobile engine that adjust the engine air intake to directly affect the combustion power of the engine. In practical scenarios, proportional–integral–derivative (PID) is a common and effective method. However, the traditional PID is difficult to satisfy the ETS performance requirements, e.g., the system response overshoot

A double-inverter-fed wound rotor induction machine (DI-WRIM) is a two-port machine capable of maintaining rated torque even at twice the rated speed. Such machines are gaining popularity in high-speed and high-power applications for their versatility and degrees of freedom in control. The existing control methods for the DI-WRIM are all based on the dynamic model of the machine, and the associated

In this article, the health difference feedback model (HDFM) is proposed to diagnose the internal short-circuit fault of a lithium-ion battery. The HDFM combines the mean model with the median model. The algorithm uses the fuzzy Kalman filter with feedback to solve the problem of inaccurate estimation in the low-state-of-charge region and the influence of short-circuit current on the battery model

Grid-connected converters are uncertain time-varying systems, whose controllers must deal with the relevant inductive content and high harmonic distortion of the sampled voltages. Adaptive controllers are feasible control strategies for these applications, because their gains are continuously adjusted in response to system perturbations, and they are also robust to unmodeled dynamics and exogenous

Miniaturization of light-emitting diodes (LEDs) has led to difficulties in characterizing photoelectric characteristics when using the conventional direct contact probe method, which risks damage to the small electrodes of LEDs, or the noncontact photoluminescence method, which can result in errors for known good die (KGD) detection. In this work, based on the photovoltaic effect and electromagnetic

In this article, we propose an instantaneous complex power control (ICPC) for a grid-tied voltage-source converter, which has two important features: it allows injecting currents with low distortion to the grid, and it allows to significantly reduce the value of the dc link capacitor, which can potentially increase the reliability of the system and decrease its cost (considering different capacitor

The instantaneous current turn- off capability of the insulated gate bipolar transistor (IGBT) devices has always been an important indicator to determine the turn- off performance of the dc circuit breakers (DCCBs). The two main failure types for IGBT devices in DCCB applications are dynamic latch-up and tail current thermal breakdown. However, the mainstream traditional turn- off methods cannot effectively

This article proposes an improved sensorless control strategy for interior permanent magnet synchronous motor (IPMSM) using high-frequency (HF) rotating signal injection method in the stationary reference frame. Conventional HF rotating signal injection methods face the problems of long convergence time and poor stability, due to the filters used in signal demodulation process. Therefore, an improved

The excitation pole of the long stator linear synchronous motor (LSLSM) used to drive the high-speed maglev train is also used as the suspension electromagnet, which makes the adjustment of the suspension system affect the excitation flux linkage of the motor when the train is running at high speed, resulting in significant nonperiodic traction force fluctuations. This article proposes a traction force

The conventional model predictive control (MPC) uses a single voltage vector for every control cycle that makes the cost function minimized through the enumeration process, which will result in relatively high steady-state fluctuation and significant computational overhead. MPCs steady-state performance can be enhanced by adding duty-cycle control and generalized double-vector control, although this

Cascaded H-bridge-based solid-state transformer (CHB-SST) has been the typical scheme in medium- and low-voltage ac/dc conversion applications, and large-size capacitance caused by second-order ripple of submodules (SMs) is the inherent problem of CHB-based systems. In this article, we propose a novel low-capacitance CHB-SST based on zero-impedance resonant push–pull (ZRPP) decoupling channel for ripple

Voltage equalizer is essential for mitigating the inconsistencies of series-connected lithium-ion batteries in electric vehicles to ensure operation life and work safety. To keep voltage balancing, voltage equalizers are widely adopted in the battery string application. However, traditional voltage equalizers have high circuit costs and large sizes due to the need for a large number of MOSFETs and

Isolated multiport converters can host loads and sources at different power and voltage levels to their ports by a single topology, giving potential merits in terms of power density and efficiency. However, the higher the number of ports, the higher the number of degrees of freedom in the modulation patterns. This high number of modulation variables complicates the optimization problem, making closed-form

Robust robotic grasping in clutter still remains a challenging problem despite its great practical value. This article presents an information-theoretic exploration approach that aims to improve the grasp estimation quality in a complex environment. First, a lightweight grasp detector that is composed of inverted residual blocks and a pyramid pooling module is proposed to make more accurate pixelwise

Redundant systems are highly favored due to their superior performance. However, rapid real-time solutions, state variable constraints, and noise-resistance of redundant systems are still challenging issues to be solved. Therefore, a novel noise-resistant adaptive gain zeroing neural network (NRAG-ZNN) is designed to handle time-varying redundant system problems with state variable constraints, and

Misalignment between human and exoskeleton joints is a common issue in exoskeletons of rigid structure, as it can lead to discomfort or even injuries. Cable-driven exoskeletons, by using human skeletal joints, remove misalignment as a potential issue. However, large parasitic forces due to cable pulling endure as a shortcoming of cable-driven exoskeletons. To address the problem, this article proposes

In this article, we propose a safe visibility-guided perception-aware trajectory optimization method for aerial tracking, which can handle occlusion and collision in complex environments simultaneously. Different from the existing methods, the key idea of the proposed method is to actively adjust the relative distance and angle between the quadrotor and the target to avoid occlusion and collision with

3-D light detection and ranging (LiDAR)-based localization for autonomous ground robot in unknown environment is a critical ability, which has been extensively studied. In this article, we propose a novel nonlinear optimization method to promote the 3-D LiDAR localization performance. First, due to that the objective function is the summation of point correspondence matching error items, a novel item

Driving assistance modules are important components to improving driver safety in driving environments, which can create overloaded multisensory information. This article introduces the concept of a head-up haptic display that assists drivers in keeping their visual attention focused, and then offers a haptic actuator that may be used as the main component in the head-up haptic display. We selected

In this article, the stator cooling system of an axial-flux permanent-magnet (PM) motor with an integer-slot distributed winding (ISDW) for high-speed, high-power electric vehicle traction applications is discussed. The aim of this research is to quantitatively figure out the power/power density boundaries of this type of axial field PM motor with the adoption of the proposed oil-immersed cooling system

Quasi-zero-stiffness (QZS) vibration isolators can achieve a considerable vibration isolation performance in the low-frequency range. However, the vibration isolation performance and stability would become worse under complex excitation environments, such as large strokes, uncertain excitation amplitudes, etc. This work proposes a hybrid time-delayed feedforward and feedback controller (HTD-FFC) to

This article contributes to the design of a second-order sliding-mode controller for the trajectory tracking problem in perturbed unicycle mobile robots. The proposed strategy takes into account the design of two particular sliding variables, which ensure the convergence of the tracking error to the origin in a finite time despite the effect of some external perturbations. The straightforward structure

The extensive application of nonlinear components and power electronic devices in power systems has led to increasingly deteriorating harmonic pollution. The rapid and high-precision harmonic detection and analysis technology will set the prerequisite for mitigating the harmonic crisis. This article presents a robust, stable, and real-time approach based on broad learning system (BLS) for detecting

Owing to the negative impedance instability of the constant power load (CPL), oscillations are induced in the output voltage of the boost converter, which may lead to voltage collapse. This article proposes a graphical strategy to tune a PID controller for the boost converter loaded with a CPL. The idea of root crossing boundaries is applied to compute the all stability region. Robustness and relative

Soft actuators have the advantages of compliance and adaptability when working with vulnerable objects, but the deformation shape of the soft actuators is difficult to measure or estimate. Soft sensors made of highly flexible and responsive materials are promising new approaches to the shape estimation of soft actuators, but suffer from highly nonlinear, hysteresis, and time-variant properties. A nonlinear

In this article, the problem of intermittent fault (IF) detection is investigated for stochastic linear time-varying (LTV) systems using dynamic event-triggered methods. Using the nonuniform sampling approach, the event-triggered system is transformed into a time-varying system with varying sampling periods. Using the moving horizon estimation strategy, a new IF detection filter is designed to generate

The underground cement pipeline network is critical in urban infrastructure, such as sewage drainage and fluid transportation. Pipelines are deeply buried, so the damage is difficult to be detected. It is of great significant to monitor the crack of pipeline in real time. In this research, a data compression and damage evaluation method of underground pipeline using musicalized sonar Gaussian mixed

Low-frequency junction temperature fluctuation caused by changes in load current or ambient temperature can severely accelerate the aging development and reduce the operational lifetime of power switching devices. Therefore, junction temperature smoothing control (JTSC) is important for high reliability operation. Conventional JTSC methods require complex additional hardware. Moreover, they are invasive

In iron and steel industry, the sintering process requires huge carbon consumption. Achieving accurate and dynamic prediction of carbon consumption in this process is of evident significance to protect the environment and raise the economic efficiency of iron and steel industry. This article develops an original dynamic modeling framework, including automatic identification of operating conditions

Accurate intersensor spatiotemporal transformation is the fundamental prerequisite for multisensor fusion. However, traditional discrete-time calibration methods have natural shortcomings when dealing with distorted and asynchronous raw measurements collected by light detection and ranging (LiDAR) and rolling shutter cameras. To this end, we propose a two-step LiDAR/camera/inertial measurement unit

This article contributes to the realization of a unified and flexible framework that can cover whole processes of a control system for learner-centered learning scenarios. It introduces the application of a pocket laboratory with a unified and flexible framework to engineering education at Wuhan University. The pocket laboratory, named Mathematics to Practice Laboratory (M2PLab), is successfully designed

An advanced magnetic hysteresis modeling, exploiting the Preisach theory and the neural networks, is applied and discussed for the simulation of the magnetization processes of magnetic components made by laser powder bed fusion. Silicon iron samples with different percentage silicon content are used for the evaluation of the accuracy and reliability of the proposed approach. Measurements of the hysteresis

The current collector is a key component of most light rail transit (LRT) trains. It draws electric power from the catenary or the power rail for each moving train. Due to wear, tear, and harsh operating environments, the current collector will malfunction, which can lead to unexpected power interruptions for the train and directly affect service reliability. This article presents an inductive coupling

The LLC resonant converter, featured with soft-switching capability, has been widely used in power conversions. For achieving the fast dynamic performance of the LLC resonant converter, it is required to increase the control bandwidth, and thus an accurate small-signal model is necessary. In this article, with the discrete-time modeling method, the small-signal model of the power stage of the LLC resonant

To avoid the cumbersome calculation of inverse kinematics and improve the efficiency of obstacle avoidance, a novel potential guided bidirectional rapidly-exploring random tree star with the direct connection strategy for redundant robot manipulators in the joint space is proposed. First, an expansion strategy based on the artificial potential field is designed in the joint space. Then, this expansion

A novel power hardware-in-the-loop interface algorithm, the virtual shifting impedance, is developed, validated, and demonstrated in this article. Building on existing interface algorithms, this method involves shifting a part of the software impedance to the hardware side to improve the stability and accuracy of power hardware-in-the-loop setups. However, compared to existing approaches, this impedance

In this article, a practical finite-time command filtered backstepping control method is proposed for a class of uncertain nonlinear systems with unknown control direction coefficients, unmodeled dynamics, and external disturbances. In this approach, practical finite-time command filters are proposed to get the differential estimations of the system signals, and such estimations are used to construct

To achieve high robustness and performance, this article proposes an enhanced observer based on a predictive error model for the deadbeat predictive current control method (DPCC-PEMO). First, the mathematical model of permanent magnet synchronous motor (PMSM), deadbeat predictive current control (DPCC) method, and disturbance analysis are presented. Second, to estimate the trend of current variation

Parameter identification is becoming an essential technology in machine driven industrial drives due to the requirements of high-performance control and online monitoring. However, for high-speed permanent magnet synchronous machines (HSPMSMs), due to the complexity and couplings between discrete-time model and low-value resistance, multiparameter estimation faces challenges. In this article, we propose

This article presents a novel zero-sequence-current suppression method for open-end winding permanent magnet synchronous motor. First, a pair of orthogonal dc signals proportional to the amplitude of the zero-sequence-current are detected through the orthogonal gate-integral circuit, which will be regarded as the projection of the zero-sequence-current on the three times synchronous rotating coordinate

In this article, we present a fast and accurate empirical stray loss model for inverter-fed three-phase induction motors (IMs). The objective of the model's development is to estimate the stray loss in an IM during its design stage and during the regular operation. With the breakthrough in power electronics, the use of inverter-fed motor-driven systems has become convenient and these systems are now

The damping effect in grid forming (GFM) control is inherently large and thus has great impact on its transient stability. Although qualitative understanding of damping has been developed in recent studies, an analytical and intuitive method for quantitative assessment of damping is still needed to be developed to date. This article visualizes the transient damping energy through the concept of damping

Virtual inertia control (VIC) allows grid-connected converter (GCC) to emulate inertia via the dc-link capacitance. Yet, such a scheme's stability impact revealed by the impedance perspective is often overlooked, resulting in coupling issues between the converter and the grid. This article presents a comprehensive analysis of the effect of the dc-link's VIC on the GCC system. The GCC's small-signal

In the renewable energy system, generally, the output voltage of renewable sources, such as photovoltaic (PV) and the fuel cell is relatively low and should be boosted to a high voltage first. However, there will be a large amount of second harmonic current (SHC) on the dc bus when powering the ac load. This article aims for suppressing the SHC in the front-end converter with a high-gain dc–dc converter

High operating cost and deficient longevity of stacks are the two primary factors that hinder the widespread commercial usage of fuel cell (FC) technology. In addition, most existing strategies concentrate solely on ameliorating system operating efficiency or fuel consumption, without fully considering the impact of other factors, such as the degradation of power source performance. Thereby, based

Skill generalization across different tasks is currently a challenging task for robots. As for recent works based on robot learning, substantial environmental interaction costs or abundant expert data are usually needed, thus causing great harm to the robot or the operating object. In this article, feature-selected adaptation transfer is proposed, aiming at accelerating the network learning process

Although the linear oscillatory machine (LOM) can directly output the reciprocating force without transmission mechanism, the most prevailing Redlich-type linear oscillatory machine (RLOM) still easily suffers from low reliability and complex fabrication process, due to its magnet mover and parallel-flux design. Moreover, it usually adopts NdFeB magnets as the only field excitation, leading to a large

This article presents a novel distributed secondary control method for dc microgrids. The method improves existing results by considering the effects of transmission line impedances and constant power loads (CPLs) on system stability. Specifically, a new parameter named “virtual current derivative (VCD)” is defined, which simplifies system analysis and facilitates the improved control design. It is

This article is concerned with the problem of resilient output tracking control for a class of discrete-time linear cyber-physical systems (CPSs) subject to denial-of-service attacks. The remote information exchange between the sensor and controller in CPSs employs a multichannel network because of its inherent advantages of resistance to destruction as well as to attacks. In order to design defense

Huge amounts of text data describing malfunction, defect, and safety hazard have been recorded in power maintenance sectors. Effectively mining such text data, and thus, classifying electrical fault types from text data bring the potential to considerably reduce the manpower in a variety of industrial applications, such as power scheduling and periodic report generation. However, short sentences in

In this article, the challenging task of estimating periodically occurring faults (POFs) in sampled-data systems is investigated. One major obstacle faced in this study is the timing misalignments between fault occurrences and observations, which is a common issue in practice. A novel approach to modeling the influence of the POFs is proposed, which utilizes an important auxiliary variable indicating

Grid-forming (GFM) control are promising for doubly fed induction generator-based wind turbines (DFIG-Based WTs) due to its grid-support ability and stable operation when connected to weak grid. However, GFM-DFIG might suffer from instability under symmetrical grid fault, if its electromagnetic and synchronous dynamics are poor. Therefore, an improved strategy of GFM-DFIG based on disturbance rejection