Search results

Prior investigations concerning misalignment resulting from journal deformation typically relied on predefined misaligned angles. Nevertheless, scant attention has been devoted to the determination of these misaligned angles. Furthermore, existing studies commonly treat the journal as rigid under such circumstances. Therefore, the present study aims to introduce a framework for determining misaligned angles and to compare outcomes between rigid and flexible journal configurations.

The bearing forces are considered as an external load leading to journal deformation. This deformation is calculated using the finite element method. The pressure distribution producing the bearing force is solved using the finite difference method. The mesh grids in the finite element and finite difference methods are matched for coupling calculation. By iteration, the pressure distribution of the lubricant film at the equilibrium position is determined.

Results show that the deformation-induced misalignment has a significant influence on the performance of the bearing when the journal flexibility is taken into account. The parametric study reveals that the misalignment relies on system parameters such as bearing length-diameter ratio and static load.

The investigation of this work provides a quantification method of misalignment of hydrodynamic bearings considering the elastic deformation of the journal, which assists in the design of bearing in a rotor-bearing system.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2023-0337/

The torque ripple and fault-tolerant capability are the two main problems for the switched reluctance motors (SRMs) in applications. The purpose of this paper, therefore, is to propose a novel 16/10 segmented SRM (SSRM) to reduce the torque ripple and improve the fault-tolerant capability in this work.

The stator of the proposed SSRM is composed of exciting and auxiliary stator poles, while the rotor consists of a series of discrete segments. The fault-tolerant and torque ripple characteristics of the proposed SSRM are studied by the finite element analysis (FEA) method. Meanwhile, the characteristics of the SSRM are compared with those of a conventional SRM with 8/6 stator/rotor poles. Finally, FEA and experimental results are provided to validate the static and dynamic characteristics of the proposed SSRM.

It is found that the proposed novel 16/10 SSRM for the application in the belt-driven starter generator (BSG) possesses these functions: less mutual inductance and high fault-tolerant capability. It is also found that the proposed SSRM provides lower torque ripple and higher output torque. Finally, the experimental results validate that the proposed SSRM runs with lower torque ripple, better output torque and fault-tolerant characteristics, making it an ideal candidate for the BSG and similar systems.

This paper presents the analysis of torque ripple and fault-tolerant capability for a 16/10 segmented switched reluctance motor in hybrid electric vehicles. Using FEA simulation and building a test bench to verify the proposed SSRM’s superiority in both torque ripple and fault-tolerant capability.

The purpose of this paper is to handle the problem of the radial disturbance caused by rotor mass unbalance and load change in a bearingless induction motor (BIM).

The active disturbance rejection controller (ADRC) is used to replace the traditional PI controller, and a cubic interpolation method is used to fit the nonlinear function of ADRC, so as to improve the control performance. Meanwhile, a disturbance observer is applied to the suspension system, and the observed disturbance acceleration is compensated to the suspension system in the form of current; thus, the suppression of the rotor radial disturbance is realized.

The proposed method can effectively suppress the radial disturbance of the rotor, meliorate the suspension performance of the motor and enhance the anti-interference ability of the system. Besides, it has excellent dynamic and static performance.

A radial disturbance control strategy of the BIM based on improved ADRC is proposed is to suppress the radial disturbance of the rotor. The improved ADRC is to enhance the control performance of the system, and the disturbance observer is designed to observe and compensate the disturbance.

The purpose of the control method proposed in this paper is to address the problem of the poor anti-interference of the suspension winding current in the traditional bearingless induction motor (BL-IM) direct suspension force control process.

A model predictive direct suspension force control of a BL-IM based on sliding mode observer is proposed in this paper. The model predictive control (MPC) is introduced to the traditional direct suspension force control to improve the anti-interference of the suspension current. A sliding mode flux linkage observer is designed and applied to the MPC system, which reduces the error of the parameter observation and improves the robustness of the system. The strategy is designed and implemented in the MATLAB/Simulink and the two-level AC speed regulation platform.

The simulation and experimental results show that the performance of the BL-IM under the control method proposed in this paper is better than that under the traditional direct suspension force control, and the suspension performance of the motor and the anti-interference of the control system are improved.

This study helps to improve the suspension performance of the motor and the anti-interference of the control system.

This paper aims to propose an effective method to verify poles polarities of switched reluctance motors (SRMs). Different from the ways of detection poles polarities by permanent magnet in SRMs, the difference of self-inductance between different winding connections is used to verify the pole polarity.

First, the winding connections with the forward and reverse series are proposed. The magnetic circuit models are established to analyze the flux linkage of different winding connections. Then, according to the difference of inductance characteristics, including the self-inductance and the mutual inductance affected by the adjacent poles, it is theoretically feasible to verify the polarity of each pole. Finally, the proposed method is verified by the simulation and experiment on a six-phase SRM.

First, compared to the reverse series, the forward series can produce larger self-inductance when one phase is excited at the same current excitation, which can be used to verify the poles polarities of one phase with different winding connection. Second, the mutual inductance can be used to distinguish the winding connections. Third, the difference of the maximum self-inductance of the winding, which is composed of two adjacent windings, can be used to verify the polarities of the adjacent poles.

This paper proposes an effective method to verify poles polarities of SRMs.

Inductance, torque and iron loss are the key parameters of switched reluctance motors for belt-driven starter generators. This paper aims to present the analysis of a segmented rotor switched reluctance motor (SSRM) with three types of winding connections for hybrid electric vehicle applications by using a two-dimensional finite element method.

The rotor of the studied SSRM consists of a series of discrete segments, while the stator is made up of exciting and auxiliary teeth. First, the concept and structures of the different winding connections are introduced. Then, the magnetic flux path of the three types of winding connections for the SSRM is described. Second, the magnetic flux distributions in the three parts, i.e. the stator yoke, the stator tooth and the rotor segment, are described in detail to calculate the iron losses. Third, three SSRMs with the different winding arrangements are analyzed and compared to evaluate the distinct features of the studied SSRM. The analysis and comparison mainly include self-inductances, mutual inductances, phase currents, output torque and iron loss.

It is found that the self-inductances of the three types of winding connections are almost equal, and only the SSRM1 has a positive mutual inductance. In addition, the current waveforms of SSRM1 and SSRM2 are regular. However, it is irregular in SSRM3. It is shown that SSRM1 has better characteristics, such as higher output torque, high power density, lower torque ripple and iron loss.

This paper proposes and analyzes three novel winding connections for the SSRM to provide guidance for enhancing the output torque and reducing the iron loss to achieve high efficiency.

This paper aims to propose an effective dynamic calibration and compensation method to solve the problem that the statically calibrated force sensor would produce large dynamic errors when measuring dynamic signals.

The dynamic characteristics of the force sensor are analyzed by modal analysis and negative step dynamic force calibration test, and the dynamic mathematical model of the force sensor is identified based on a generalized least squares method with a special whitening filter. Then, a compensation unit is constructed to compensate the dynamic characteristics of the force measurement system, and the compensation effect is verified based on the step and knock excitation signals.

The dynamic characteristics of the force sensor obtained by modal analysis and dynamic calibration test are consistent, and the time and frequency domain characteristics of the identified dynamic mathematical model agree well with the actual measurement results. After dynamic compensation, the dynamic characteristics of the force sensor in the frequency domain are obviously improved, and the effective operating frequency band is widened from 500 Hz to 1,560 Hz. In addition, in the time domain, the rise time of the step response signal is reduced from 0.29 ms to 0.17 ms, and the overshoot decreases from 26.6% to 9.8%.

An effective dynamic calibration and compensation method is proposed in this paper, which can be used to improve the dynamic performance of the strain-gauge-type force sensor and reduce the dynamic measurement error of the force measurement system.

COVID-19 (C19) has been destroying the world's health and emergency response system for almost the past year. Policymakers and health practitioners are trying their best to save the public through various policy development and initiatives in this regard. This study aims to examine the containment measures and their impacts on Australia's C19 situation in Australia's COVIDsafe app background.

This study investigates the role of the Australian Government's (AG) Health Containment (HC) and Stringency response (SR) in combating the C19 situation in Australia. The time horizon has been taken from January to October 2020 and applied Linear Regression with graphical demonstration analysis by STATA-18 version and MS Word chart features.

By applying linear regression and graphical demonstration, statistics revealed that AG made various policy developments during the C19 pandemic. However, due to inconsistent and unsustainable measures, the second C19 wave hit Australia much harder than the first wave. COVIDsafe app has been a vital AG in this regard; however, it did not show its progress during the second wave due to privacy issues. After the more focused and aggressive research and development measures, AG overcame the App drawbacks and controlled the situation, demonstrating 92% recovered statistics from C19.

The study concludes that AG should enforce many prudent policy measures and distinct E-government features in the COVIDsafe app and make it secure so people will use it in probable forthcoming C19 waves.

This study has examined the Government of Australia's containment measures in the background discussion of the COVIDsafe app.

E-government development (EGD) is vital in enhancing the institutional quality and sustainable public service (SPS) delivery by eradicating corruption and cybersecurity crimes.

The present study applied econometric fixed-effect (FE) regression analysis and random forest (RF) algorithm through machine learning for comprehensive estimations in achieving SPS. This study gauges the nexus between the EGD as an independent variable and public service sustainability (PSS) as a proxy of public health services as a dependent variable in the presence of two moderators, corruption and cybersecurity indices from 47 Asian countries economies from 2015 to 2019.

The computational estimation and econometric findings show that EGD quality has improved with time in Asia and substantially promoted PSS. It further explores that exercising corruption control measures and introducing sound cybersecurity initiatives enhance PSS's quality and support the EDG effect much better.

The study concludes that E-Government has positively impacted PSS (healthcare) in Asia while controlling cybersecurity and institutional malfunctioning made an E-Government system healthier and SPS development in Asia.

This study added a novel contribution to existing E-Government and public services literature by comprehensively applied FE regression and RF algorithm analysis. Moreover, E-Government and cybersecurity improvement also has taken under consideration for PSS in Asian economies.

Robot vision is a fundamental device for human–robot interaction and robot complex tasks. In this paper, the authors aim to use Kinect and propose a feature graph fusion (FGF) for robot recognition.

The feature fusion utilizes red green blue (RGB) and depth information to construct fused feature from Kinect. FGF involves multi-Jaccard similarity to compute a robust graph and word embedding method to enhance the recognition results.

The authors also collect DUT RGB-Depth (RGB-D) face data set and a benchmark data set to evaluate the effectiveness and efficiency of this method. The experimental results illustrate that FGF is robust and effective to face and object data sets in robot applications.

The authors first utilize Jaccard similarity to construct a graph of RGB and depth images, which indicates the similarity of pair-wise images. Then, fusion feature of RGB and depth images can be computed by the Extended Jaccard Graph using word embedding method. The FGF can get better performance and efficiency in RGB-D sensor for robots.