The multi-phase motor drive system with multiple H-bridge power supply has high fault tolerance,which is widely used in aerospace,electric vehicle,ship integrated power system and other fields.In this paper,a fault-to...The multi-phase motor drive system with multiple H-bridge power supply has high fault tolerance,which is widely used in aerospace,electric vehicle,ship integrated power system and other fields.In this paper,a fault-tolerant control strategy based on decoupling control and stator current compensation is proposed for the propulsion system of five-phase PMSM with independent neutrals.Firstly,the mathematical model of PMSM is established by using vector space decoupling method;Secondly,a stator current compensation method is adopted to carry out fault-tolerant control after the motor has single-phase and two-phase open-circuit faults and the fault-tolerant control system based on decoupling control is established;Finally,the decoupling control model and the fault-tolerant control of stator current compensation are verified by the simulation and experiment.The simulation and experiment results show that the method can reduce the torque ripple caused by the stator winding open-circuit fault,and the operation performance of the motor under fault condition is significantly improved.展开更多
For the two-level five-phase permanent magnet synchronous motor(FP-PMSM)drive system,an improved finite-control-set model predictive torque control(MPTC)strategy is adopted to reduce torque ripple and improve the cont...For the two-level five-phase permanent magnet synchronous motor(FP-PMSM)drive system,an improved finite-control-set model predictive torque control(MPTC)strategy is adopted to reduce torque ripple and improve the control performance of the system.The mathematical model of model reference adaptive system(MRAS)of FP-PMSM is derived and a method based on fractional order sliding mode(FOSM)is proposed to construct the model reference adaptive system(FOSMMRAS)to improve the motor speed estimation accuracy and eliminate the sliding mode integral saturation effect.The simulation results show that the FP-PMSM speed sensorless FCS-MPTC system based on FOSM-MRAS has strong robustness,good dynamic performance and static performance,and high reliability.展开更多
In traditional analytical method(AM),the magnetic saturation is always ignored to simplify the calculation process.However,synchronous reluctance motors(SynRMs)often operate around saturation point to achieve higher t...In traditional analytical method(AM),the magnetic saturation is always ignored to simplify the calculation process.However,synchronous reluctance motors(SynRMs)often operate around saturation point to achieve higher torque density.Therefore,a new AM is proposed,in which the saturation of stator iron has been considered.The key of the proposed method includes a saturation factor,and an iterative method is adopted to compute the saturation factor in the SynRM by increasing the air-gap length.Especially,the proposed AM can be applied to a SynRM even with shifted-asymmetrical-salient-poles.In the process of AM,the expression of stator magnetomotive force(MMF)is built firstly.Additionally,the air-gap density including slotting effect and salient-poles is calculated.Then,the rotor MMF under saturation of the stator iron is obtained.Therefore,the precision of the instantaneous torque can be improved significantly.Eventually,by the verification of finite elements method(FEM)and experiments,the torque performance of SynRMs with shifted asymmetrical rotor can be predicted accurately by the proposed AM.展开更多
Based on the principle of direct torque control,a DTC(Direct Torque Control)system with five-phase induction motor has been studied.Providing direct control of stator flux and electromagnetic torque by optimized volta...Based on the principle of direct torque control,a DTC(Direct Torque Control)system with five-phase induction motor has been studied.Providing direct control of stator flux and electromagnetic torque by optimized voltage vector,five-phase induction motor enhances flexibility of the invert states selection by increasing the number of voltage vectors,resulting in more precise control of stator flux and electromagnetic torque.The model of DTC for five-phase induction motor is constructed on equations and the method of approximate circle of torque track is used to conduct the simulation analysis of the system.The simulation results demonstrate that the DTC for five-phase induction motor control has merits of little calculation compared with vector control,simple structure,fast response and greater dynamic performance.展开更多
In this article, an inter-turn short-circuit(ITSC) fault diagnosis and severity estimation method based on extended state observer(ESO) and convolutional neural network(CNN) is proposed for five-phase permanent magnet...In this article, an inter-turn short-circuit(ITSC) fault diagnosis and severity estimation method based on extended state observer(ESO) and convolutional neural network(CNN) is proposed for five-phase permanent magnet synchronous motor(PMSM) drives. The relationship between fault parameters and motor parameters is analyzed and the equivalent model of ITSC faults in the natural reference frame is accordingly derived. To achieve fault detection and location, the short-circuit turn ratio and short-circuit current are integrated as the fault diagnosis index. According to the model of the shortcircuit current, an ESO is designed for the estimation of the fault diagnosis index. Further, the sensitivity analysis among fault parameters is conducted to evaluate the short-circuit turn ratio and the short-circuit resistance. Subsequently, the postfault current, back electromotive force, electrical angular velocity, q1-axis current reference and the fault diagnosis index are selected as the input signals of CNN to estimate the short-circuit turn ratio. This approach not only resolves parameter coupling challenges but also provides a quantitative assessment of fault severity. Finally, simulations and experiments under different operating points validate the effectiveness of the proposed method.展开更多
This paper compares the torque characteristics of single stator permanent magnet synchronous motor(PMSM)and double-stator PMSM under different split-ratios,air-gap lengths and shaft diameters by finite element method....This paper compares the torque characteristics of single stator permanent magnet synchronous motor(PMSM)and double-stator PMSM under different split-ratios,air-gap lengths and shaft diameters by finite element method.Firstly,the effects of split-ratio towards the torque characteristics of the two motor structures under different air-gap lengths are researched,the results show that the optimal split-ratios of the two motor structures do not change under different air-gap lengths,and the optimal split-ratio of the double-stator motor is greater than that of single-stator,and the torque of the double-stator motor is greater than that of single-stator motor with arbitrary split-ratio under the same air-gap length;Finally,the effects of the shaft diameter to the torque of the two motor structures are investigated,obtaining that with the increasing of shaft diameter,the electromagnetic torque of the single-stator motor is almost unchanged,however,the torque of the double-stator is gradually reduced,when the shaft diameter reached a certain extent,the electromagnetic torque of the double-stator motor is smaller than that of single-stator motor with the split ratio within a certain range,and the torque/quality ratio of the double-stator motor is smaller than that of single-stator motor with their optimal split ratio separately.展开更多
Adult-born oligodendrocytes are continuously produced in the brains of rodents.The functional role of these cells has been linked to the motor-related activities of healthy animals and is vital for acquiring new motor...Adult-born oligodendrocytes are continuously produced in the brains of rodents.The functional role of these cells has been linked to the motor-related activities of healthy animals and is vital for acquiring new motor skills.However,the relationship between these cells and the control of motor-related activities has not been investigated in pathological conditions.Therefore,the aim of this study is to investigate the role of oligodendrocytes in depression-related motor deficits and the effects of training.Psychomotor retardation is a key symptom of depression.Consistent with the impairments observed in rodent motor performance,the proliferation and activation of adult-born oligodendrocytes are altered in a corticosterone-induced stress paradigm.Therapeutic rotarod training can alleviate these symptoms by reversing the aforementioned changes.Notably,these alterations are particularly pronounced in layer I of the motor cortex.Thus,this study provides evidence of the potential functional involvement of adult-born oligodendrocytes in the motor impairments observed in the depressed animals.Additionally,it offers preliminary results for further investigation into layer I of the motor cortex in relation to these pathological conditions.展开更多
Motor neuron diseases are sporadic or inherited fatal neurodegenerative conditions.They selectively affect the upper and/or lower motor neurons in the brain and spinal cord and feature a slow onset and a subacute cour...Motor neuron diseases are sporadic or inherited fatal neurodegenerative conditions.They selectively affect the upper and/or lower motor neurons in the brain and spinal cord and feature a slow onset and a subacute course contingent upon the site of damage.The main types include amyotrophic lateral sclerosis,progressive muscular atrophy,primary lateral sclerosis,and progressive bulbar palsy,the pathological processes of which are largely identical,with the main disparity lying in the location of the lesions.Amyotrophic lateral sclerosis is the representative condition in this group of diseases,while other types are its variants.Hence,this article mainly focuses on the advancements and challenges in drug research for amyotrophic lateral sclerosis but also briefly addresses several other important degenerative motor neuron diseases.Although the precise pathogenesis remains elusive,recent advancements have shed light on various theories,including gene mutation,excitatory amino acid toxicity,autoimmunology,and neurotrophic factors.The US Food and Drug Administration has approved four drugs for use in delaying the progression of amyotrophic lateral sclerosis:riluzole,edaravone,AMX0035,and tofersen,with the latter being the most recent to receive approval.However,following several phaseⅢtrials that failed to yield favorable outcomes,AMX0035 has been voluntarily withdrawn from both the US and Canadian markets.This article presents a comprehensive summary of drug trials primarily completed between January 1,2023,and June 30,2024,based on data sourced from clinicaltrials.gov.Among these trials,five are currently in phaseⅠ,seventeen are in phaseⅡ,and eleven are undergoing phaseⅢevaluation.Notably,24 clinical trials are now investigating potential disease-modifying therapy drugs,accounting for the majority of the drugs included in this review.Some promising drugs being investigated in preclinical studies,such as ATH-1105,are included in our analysis,and another review in frontiers in gene therapy and immunotherapy has demonstrated their therapeutic potential for motor neuron diseases.This article was written to be an overview of research trends and treatment prospects related to motor neuron disease drugs,with the aim of highlighting the latest potentialities for clinical therapy.展开更多
Deep brain stimulation(DBS)is an established therapeutic intervention for people with Parkinson’s disease(PwPD)and is increasingly being utilized for other neurological disorders.Although effective in alleviating mot...Deep brain stimulation(DBS)is an established therapeutic intervention for people with Parkinson’s disease(PwPD)and is increasingly being utilized for other neurological disorders.Although effective in alleviating motor symptoms and reducing medication requirements,DBS has undergone minimal conceptual evolution and still relies on continuous high-frequency electrical stimulation.In Parkinson’s disease(PD),this persistent stimulation may cause adverse effects,including dysarthria,stimulation-induced dyskinesia,impulsivity,and mood alterations.Additionally,the continuous energy demand of current DBS systems accelerates battery depletion,necessitating more frequent battery charging or battery replacement surgeries,increasing risks,burden,and costs.Basic neuroscience research has long demonstrated that exogenous electrical stimulation can induce persistent changes to synaptic connections,known as long-term plasticity.展开更多
The generation of human induced pluripotent stem cell-derived motor neurons overcomes limited access to human tissues and offers an unprecedented approach to modeling motor neuron diseases such as dystonia and amyotro...The generation of human induced pluripotent stem cell-derived motor neurons overcomes limited access to human tissues and offers an unprecedented approach to modeling motor neuron diseases such as dystonia and amyotrophic lateral sclerosis.Motor neurons generated through different strategies may exhibit substantial differences in purity,maturation,characterization,and even neuronal identity,leading to variable outcomes in disease modeling and drug screening.However,very few comparative studies have been conducted to determine the similarities and differences among motor neurons prepared via different protocols.In this study,we prepared human induced pluripotent stem cell-derived motor neurons via lentiviral delivery of transcription factors and chemical induction and performed a systematic comparative analysis.We found that motor neurons generated by both approaches showed typical motor neuron morphology and robustly expressed motor neuron-specific markers,such as nuclear homeobox transcription factor 9 and choline acetyltransferase.The chemical induction protocol utilizes a combination of small molecules to induce motor neuron differentiation,offering a significantly faster maturation time of 35 days compared to 46 days with lentiviral delivery of transcription factors.Additionally,while lentiviral delivery of transcription factors are suitable for downstream biochemical analysis,chemical induction are more applicable for therapeutic approaches as they avoid the use of lentiviruses.Both approaches produce motor neurons with high purity(>95%)and yield.No significant differences were found between chemical induction and lentiviral delivery of transcription factors in terms of motor neuron markers and maturation markers.These robust methodologies offer researchers powerful tools for investigating motor neuron diseases and potential therapeutic strategies.展开更多
Purpose:This study examined potential differences in strength,muscle morphology,and motor unit(MU)behavior of the abductor digiti minimi(ADM)between normal-fat(NF)and over-fat(OF)males.Methods:Dual-energy X-ray absorp...Purpose:This study examined potential differences in strength,muscle morphology,and motor unit(MU)behavior of the abductor digiti minimi(ADM)between normal-fat(NF)and over-fat(OF)males.Methods:Dual-energy X-ray absorptiometry assessed percent body fat(%BF).Ultrasonography determined muscle cross-sectional area(CSA),echo intensity(EI),and subcutaneous fat(s FAT).MU behavior was assessed during isometric muscle actions at 50%of maximal voluntary contraction(MVC)by analyzing the y-intercepts and slopes for the MU action potential amplitude(MUAPAMP)vs.recruitment threshold(RT)relationships,the A and B terms for the mean firing rate(MFR)vs.RT relationships,and normalized electromyographic amplitude(N-EMGRMS).MU firing times and waveforms were validated with reconstruct-and-test and spike trigger average procedures.Results:%BF was greater for OF(25.70%±5.40%)than NF(16.50%±2.20%;p<0.001).MVC was greater for NF(27.13±7.16)N than OF([19.89±4.96]N;p=0.014).CSA was greater for NF(2.48±0.39)cm^(2)than OF([1.95±0.47]cm^(2);p=0.011).The y-intercepts for the MUAPAMPvs.RT relationships were greater for NF(0.283±0.254)m V than OF([-0.221±0.659]m V;p=0.004).The B terms for the MFR vs.RT relationships were greater for NF(-0.024±0.003)pps/%MVC than OF([-0.031±0.009]pps/%MVC;p=0.038).N-EMGRMSwas similar between groups(p=0.463).Conclusion:Maximal strength,muscle size,and MU recruitment and firing rate patterns for a non-weight bearing muscle differed between normal-fat and over-fat males.展开更多
This paper proposes a collaborative design method for enhancing the power factor and torque of electric motors.First,the intrinsic relationship between flux linkage analysis of the permanent magnet(PM)and armature fie...This paper proposes a collaborative design method for enhancing the power factor and torque of electric motors.First,the intrinsic relationship between flux linkage analysis of the permanent magnet(PM)and armature field and the power factor is explored.Then,the connection between flux linkage and harmonics is established,clarifying the mechanism for improving power factor and torque.Improvements are focused on the PM and permeance.Regarding the PM structure,employing a Y-shaped PM structure effectively increases PM utilization,reduces leakage flux at the outer ends,and enhances the PM flux linkage.Concerning permeance,stator tooth design is optimized to cooperatively improve permeance harmonics,reduce the non-working flux linkage of the armature field,and enhance the fundamental modulation wave of the armature field responsible for torque generation.This improves the power factor while maintaining motor torque.Finally,through PM structural design,the motor torque performance is optimized.Furthermore,the performance of the Y-shaped PM motor is evaluated.A prototype was manufactured and tested.Theoretical analysis and experimental results demonstrate the effectiveness of the proposed method to a significant extent.展开更多
To explore the distribution law of the temperature field in the motor pump and the influence of the fanshaped DC channel with spoiler in the pump housing on its heat dissipation performance.This study takes the arc-ge...To explore the distribution law of the temperature field in the motor pump and the influence of the fanshaped DC channel with spoiler in the pump housing on its heat dissipation performance.This study takes the arc-gear type hydraulicmotor pump as the research object.In COMSOL,a coupled heat transfer simulationmodel of themotor pump’s fluid-solid coupling is established,and the internal temperature field characteristics are analyzed.To improve the heat dissipation effect of the motor pump,it is proposed to arrange spoiler in the fan-shaped DC channel of the pump housing to enhance heat dissipation.Three types of spoilers,namely,wing-shaped,inclined rectangle-shaped,and wave-shaped,are designed.The simulation results show that when the motor pump operates under rated conditions,due to the poor heat dissipation environment inside the motor pump,the high-temperature areas of the motor pump are concentrated in the rotor and permanent magnet parts.After arranging the spoiler,the turbulent kinetic energy and vorticity in the fan-shaped DC channel of the pump housing are significantly enhanced.All three spoiler structures can reduce the maximum temperature of each component of the motor.According to the comprehensive performance evaluation criterion(PEC),the inclined rectangle-shaped structure has the best comprehensive heat transfer performance(PEC=1.114),while the wave-shaped structure has higher heat transfer efficiency but greater pressure loss.The wing-shaped structure has relatively limited enhancement effect on heat dissipation.This study systematically quantifies the influence of different spoiler structures on heat dissipation performance and flowresistance characteristics,providing a solution for enhancing the heat dissipation of the motor pump.展开更多
The development of brain-computer interfaces(BCI)based on motor imagery(MI)has greatly improved patients’quality of life with movement disorders.The classification of upper limb MI has been widely studied and applied...The development of brain-computer interfaces(BCI)based on motor imagery(MI)has greatly improved patients’quality of life with movement disorders.The classification of upper limb MI has been widely studied and applied in many fields,including rehabilitation.However,the physiological representations of left and right lower limb movements are too close and activated deep in the cerebral cortex,making it difficult to distinguish their features.Therefore,classifying lower limbs motor imagery is more challenging.In this study,we propose a feature extraction method based on functional connectivity,which utilizes phase-locked values to construct a functional connectivity matrix as the features of the left and right legs,which can effectively avoid the problem of physiological representations of the left and right lower limbs being too close to each other during movement.In addition,considering the topology and the temporal characteristics of the electroencephalogram(EEG),we designed a temporal-spatial convolutional network(TSGCN)to capture the spatiotemporal information for classification.Experimental results show that the accuracy of the proposed method is higher than that of existing methods,achieving an average classification accuracy of 73.58%on the internal dataset.Finally,this study explains the network mechanism of left and right foot MI from the perspective of graph theoretic features and demonstrates the feasibility of decoding lower limb MI.展开更多
A surface pyrolysis and gas-phase combustion of the Ammonium Perchlorate(AP)/Hydroxy Terminated Polybutadiene(HTPB)composite propellant reaction kinetic mechanism with five-step chemical reaction is adopted.The effect...A surface pyrolysis and gas-phase combustion of the Ammonium Perchlorate(AP)/Hydroxy Terminated Polybutadiene(HTPB)composite propellant reaction kinetic mechanism with five-step chemical reaction is adopted.The effects of helium injection on the burning rate and combustion of AP/HTPB propellant are analyzed in details,and the characteristics of motor performance are obtained.The numerical simulation results demonstrate that helium injection enhances the combustion chamber pressure,thereby increasing the burning rate of propellant.However,the primary combustion reaction of the AP/HTPB propellant takes place within a thin layer on the burning surface,so the low-temperature helium has minimal impact on the gasphase combustion.Ultimately,the helium not only elevates the nozzle exit velocity,resulting in specific impulse gain,but also reduces the exhaust plume temperature.With an increase of helium mass flow rate,the area of the velocity increase zone at the nozzle exit continuously decreases,but the average velocity in the motor exit continuously increases.Overall,when the helium flow rate is 2.5 kg/s,the specific impulse can reach 10.5%.Reducing the helium injection hole diameter enhances mixing of helium and combustion gas and expands the velocity increase zone,thereby maximizing the exit velocity gain in average velocity at the nozzle exit.When the injection hole diameter is reduced from 100 mm to 20 mm,the specific impulse gain increases from 3.1%to 10.6%.Furthermore,increasing helium injection temperature greatly boosts the velocity of the mixed gas with the same helium mass fraction ultimately improving specific impulse.展开更多
The increasing global prevalence of mild cognitive impairment(MCI)necessitates a paradigm shift in early detection strategies.Conventional neuropsychological assessment methods,predominantly paper-and-pencil tests suc...The increasing global prevalence of mild cognitive impairment(MCI)necessitates a paradigm shift in early detection strategies.Conventional neuropsychological assessment methods,predominantly paper-and-pencil tests such as the Mini-Mental State Examination and the Montreal Cognitive Assessment,exhibit inherent limitations with respect to accessibility,administration burden,and sensitivity to subtle cognitive decline,particularly among diverse populations.This commentary critically examines a recent study that champions a novel approach:The integration of gait and handwriting kinematic parameters analyzed via machine learning for MCI screening.The present study positions itself within the broader landscape of MCI detection,with a view to comparing its advantages against established neuropsychological batteries,advanced neuroimaging(e.g.,positron emission tomography,magnetic resonance imaging),and emerging fluid biomarkers(e.g.,cerebrospinal fluid,blood-based assays).While the study demonstrates promising accuracy(74.44%area under the curve 0.74 with gait and graphic handwriting)and addresses key unmet needs in accessibility and objectivity,we highlight its cross-sectional nature,limited sample diversity,and lack of dual-task assessment as areas for future refinement.This commentary posits that kinematic biomarkers offer a distinctive,scalable,and ecologically valid approach to widespread MCI screening,thereby complementing existing methods by providing real-world functional insights.Future research should prioritize longitudinal validation,expansion to diverse cohorts,integration with multimodal data including dual-tasking,and the development of highly portable,artificial intelligence-driven solutions to achieve the democratization of early MCI detection and enable timely interventions.展开更多
Motor imbalance is a critical failure mode in rotating machinery,potentially causing severe equipment damage if undetected.Traditional vibration-based diagnostic methods rely on direct sensor contact,leading to instal...Motor imbalance is a critical failure mode in rotating machinery,potentially causing severe equipment damage if undetected.Traditional vibration-based diagnostic methods rely on direct sensor contact,leading to installation challenges and measurement artifacts that can compromise accuracy.This study presents a novel radar-based framework for non-contact motor imbalance detection using 24 GHz continuous-wave radar.A dataset of 1802 experimental trials was sourced,covering four imbalance levels(0,10,20,30 g)across varying motor speeds(500–1500 rpm)and load torques(0–3 Nm).Dual-channel in-phase and quadrature radar signals were captured at 10,000 samples per second for 30-s intervals,preserving both amplitude and phase information for analysis.A multi-domain feature extraction methodology captured imbalance signatures in time,frequency,and complex signal domains.From 65 initial features,statistical analysis using Kruskal–Wallis tests identified significant descriptors,and recursive feature elimination with Random Forest reduced the feature set to 20 dimensions,achieving 69%dimensionality reduction without loss of performance.Six machine learning algorithms,Random Forest,Extra Trees Classifier,Extreme Gradient Boosting,Categorical Boosting,Support Vector Machine with radial basis function kernel,and k-Nearest Neighbors were evaluated with grid-search hyperparameter optimization and five-fold cross-validation.The Extra Trees Classifier achieved the best performance with 98.52%test accuracy,98%cross-validation accuracy,and minimal variance,maintaining per-class precision and recall above 97%.Its superior performance is attributed to its randomized split selection and full bootstrapping strategy,which reduce variance and overfitting while effectively capturing the nonlinear feature interactions and non-normal distributions present in the dataset.The model’s average inference time of 70 ms enables near real-time deployment.Comparative analysis demonstrates that the radar-based framework matches or exceeds traditional contact-based methods while eliminating their inherent limitations,providing a robust,scalable,and noninvasive solution for industrial motor condition monitoring,particularly in hazardous or space-constrained environments.展开更多
Stroke and traumatic brain injury lead to upper motor neuron syndrome,which is characterized by muscle spasticity or paresis of varying severity depending on the lesion’s location and extent.Current treatments are mo...Stroke and traumatic brain injury lead to upper motor neuron syndrome,which is characterized by muscle spasticity or paresis of varying severity depending on the lesion’s location and extent.Current treatments are mostly symptomatic with limited efficacy and significant side effects.Nerve transfer techniques,such as the contralateral L4 ventral root transfer in animal models and C7 root transfer in both animal and clinical studies,have been shown to reduce spasticity and improve function in upper motor neuron syndrome;however,they lack selectivity.Our hypothesis is that using a selective peripheral donor nerve from the contralateral side,rather than the entire nerve root,may represent an effective nerve transfer and provide a robust basis for future research on selective muscle reinnervation in upper motor neuron syndrome.Ten rats underwent a contralateral ulnar-to-ulnar nerve transfer procedure.Electrophysiological measurements were conducted twelve weeks post-surgery to assess successful reinnervation of the contralateral flexor carpi ulnaris muscle.Additionally,muscle biopsies of the reinnervated flexor carpi ulnaris were harvested to examine the muscle fiber type composition,cross-sectional area,and collagen content as well as compare them to naive counterparts.Axon quantification of the reinnervated nerves was also performed.All rats recovered uneventfully,maintaining the use of both paws post-surgery.Electrophysiological tests confirmed the successful reinnervation of the flexor carpi ulnaris muscle.Muscle fiber type composition,cross-sectional area,and collagen content did not show statistically significant changes.Axon counts indicated successful nerve regeneration without architectural disruption.In conclusion,we were able to demonstrate this novel contralateral nerve transfer model’s feasibility,reproducibility,and safety as well as achieve effective muscle reinnervation.This model provides a valuable tool for further research on selective muscle reinnervation and treatment of upper motor neuron syndrome,with potential implications for improving clinical outcomes in stroke and traumatic brain injury patients.展开更多
Owing to the multi-degree-of-freedom characteristics and inherent fault-tolerant capacity,six-phase motors have been widely adopted in high-power applications,such as electric vehicle propulsion and aerospace systems....Owing to the multi-degree-of-freedom characteristics and inherent fault-tolerant capacity,six-phase motors have been widely adopted in high-power applications,such as electric vehicle propulsion and aerospace systems.This paper presents the fault-tolerant control strategy of symmetrical six-phase permanent magnet synchronous motor(SSPMSM)under an isolated neutral point topology and proposes a fault diagnosis scheme based on joint diagnosis of multiple variables.First,two mathematical models of SSPMSM and their relationship are established.Subsequently,the current vectors in the torque subspace and harmonic subspace of the two winding sets under fault conditions are analyzed,and the cause of post-fault torque ripple is explained as resulting from controller conflict.In addition,a multivariate fault diagnosis scheme based on voltage threshold in the x-y subspace and current trajectory characteristics in theα-βsubspace is proposed to enhance the diagnostic accuracy.Finally,the feasibility and stability of the proposed control and diagnosis methods are verified by experiments.展开更多
Spinal cord injury(SCI)interrupts the flow of information between the brain and the spinal cord,thus leading to a loss of sensory information and motor paralysis of the body below the lesion.Surprisingly,most SCIs are...Spinal cord injury(SCI)interrupts the flow of information between the brain and the spinal cord,thus leading to a loss of sensory information and motor paralysis of the body below the lesion.Surprisingly,most SCIs are incomplete and spare supraspinal pathways,especially those located within the peripheral white matter of the spinal cord,which includes reticulospinal pathways originating from the medullary reticular formation.Whereas there is abundant literature about the motor cortex,its corticospinal pathway,and its capacity to modulate functional recovery after SCI,less is known about the medullary reticular formation and its reticulospinal pathway.展开更多
文摘The multi-phase motor drive system with multiple H-bridge power supply has high fault tolerance,which is widely used in aerospace,electric vehicle,ship integrated power system and other fields.In this paper,a fault-tolerant control strategy based on decoupling control and stator current compensation is proposed for the propulsion system of five-phase PMSM with independent neutrals.Firstly,the mathematical model of PMSM is established by using vector space decoupling method;Secondly,a stator current compensation method is adopted to carry out fault-tolerant control after the motor has single-phase and two-phase open-circuit faults and the fault-tolerant control system based on decoupling control is established;Finally,the decoupling control model and the fault-tolerant control of stator current compensation are verified by the simulation and experiment.The simulation and experiment results show that the method can reduce the torque ripple caused by the stator winding open-circuit fault,and the operation performance of the motor under fault condition is significantly improved.
基金National Natural Science Foundation of China(No.51867012)。
文摘For the two-level five-phase permanent magnet synchronous motor(FP-PMSM)drive system,an improved finite-control-set model predictive torque control(MPTC)strategy is adopted to reduce torque ripple and improve the control performance of the system.The mathematical model of model reference adaptive system(MRAS)of FP-PMSM is derived and a method based on fractional order sliding mode(FOSM)is proposed to construct the model reference adaptive system(FOSMMRAS)to improve the motor speed estimation accuracy and eliminate the sliding mode integral saturation effect.The simulation results show that the FP-PMSM speed sensorless FCS-MPTC system based on FOSM-MRAS has strong robustness,good dynamic performance and static performance,and high reliability.
基金This work was supported in part by the National Natural Science Foundation of China(51707083)in part by the Natural Science Foundation of Jiangsu Province(BK20190848)+1 种基金in part by the China Postdoctoral Science Foundation(2019M661746)by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘In traditional analytical method(AM),the magnetic saturation is always ignored to simplify the calculation process.However,synchronous reluctance motors(SynRMs)often operate around saturation point to achieve higher torque density.Therefore,a new AM is proposed,in which the saturation of stator iron has been considered.The key of the proposed method includes a saturation factor,and an iterative method is adopted to compute the saturation factor in the SynRM by increasing the air-gap length.Especially,the proposed AM can be applied to a SynRM even with shifted-asymmetrical-salient-poles.In the process of AM,the expression of stator magnetomotive force(MMF)is built firstly.Additionally,the air-gap density including slotting effect and salient-poles is calculated.Then,the rotor MMF under saturation of the stator iron is obtained.Therefore,the precision of the instantaneous torque can be improved significantly.Eventually,by the verification of finite elements method(FEM)and experiments,the torque performance of SynRMs with shifted asymmetrical rotor can be predicted accurately by the proposed AM.
文摘Based on the principle of direct torque control,a DTC(Direct Torque Control)system with five-phase induction motor has been studied.Providing direct control of stator flux and electromagnetic torque by optimized voltage vector,five-phase induction motor enhances flexibility of the invert states selection by increasing the number of voltage vectors,resulting in more precise control of stator flux and electromagnetic torque.The model of DTC for five-phase induction motor is constructed on equations and the method of approximate circle of torque track is used to conduct the simulation analysis of the system.The simulation results demonstrate that the DTC for five-phase induction motor control has merits of little calculation compared with vector control,simple structure,fast response and greater dynamic performance.
基金supported in part by the National Natural Science Foundation of China under Grant 52307056in part by the Natural Science Foundation of Jiangsu Province under Grant BK20210475。
文摘In this article, an inter-turn short-circuit(ITSC) fault diagnosis and severity estimation method based on extended state observer(ESO) and convolutional neural network(CNN) is proposed for five-phase permanent magnet synchronous motor(PMSM) drives. The relationship between fault parameters and motor parameters is analyzed and the equivalent model of ITSC faults in the natural reference frame is accordingly derived. To achieve fault detection and location, the short-circuit turn ratio and short-circuit current are integrated as the fault diagnosis index. According to the model of the shortcircuit current, an ESO is designed for the estimation of the fault diagnosis index. Further, the sensitivity analysis among fault parameters is conducted to evaluate the short-circuit turn ratio and the short-circuit resistance. Subsequently, the postfault current, back electromotive force, electrical angular velocity, q1-axis current reference and the fault diagnosis index are selected as the input signals of CNN to estimate the short-circuit turn ratio. This approach not only resolves parameter coupling challenges but also provides a quantitative assessment of fault severity. Finally, simulations and experiments under different operating points validate the effectiveness of the proposed method.
基金supported in part by the National Natural Science Foundation of China under Grant 51977011。
文摘This paper compares the torque characteristics of single stator permanent magnet synchronous motor(PMSM)and double-stator PMSM under different split-ratios,air-gap lengths and shaft diameters by finite element method.Firstly,the effects of split-ratio towards the torque characteristics of the two motor structures under different air-gap lengths are researched,the results show that the optimal split-ratios of the two motor structures do not change under different air-gap lengths,and the optimal split-ratio of the double-stator motor is greater than that of single-stator,and the torque of the double-stator motor is greater than that of single-stator motor with arbitrary split-ratio under the same air-gap length;Finally,the effects of the shaft diameter to the torque of the two motor structures are investigated,obtaining that with the increasing of shaft diameter,the electromagnetic torque of the single-stator motor is almost unchanged,however,the torque of the double-stator is gradually reduced,when the shaft diameter reached a certain extent,the electromagnetic torque of the double-stator motor is smaller than that of single-stator motor with the split ratio within a certain range,and the torque/quality ratio of the double-stator motor is smaller than that of single-stator motor with their optimal split ratio separately.
基金supported by Hong Kong Health and Medical Research Fund,No.02133206(to KFS).
文摘Adult-born oligodendrocytes are continuously produced in the brains of rodents.The functional role of these cells has been linked to the motor-related activities of healthy animals and is vital for acquiring new motor skills.However,the relationship between these cells and the control of motor-related activities has not been investigated in pathological conditions.Therefore,the aim of this study is to investigate the role of oligodendrocytes in depression-related motor deficits and the effects of training.Psychomotor retardation is a key symptom of depression.Consistent with the impairments observed in rodent motor performance,the proliferation and activation of adult-born oligodendrocytes are altered in a corticosterone-induced stress paradigm.Therapeutic rotarod training can alleviate these symptoms by reversing the aforementioned changes.Notably,these alterations are particularly pronounced in layer I of the motor cortex.Thus,this study provides evidence of the potential functional involvement of adult-born oligodendrocytes in the motor impairments observed in the depressed animals.Additionally,it offers preliminary results for further investigation into layer I of the motor cortex in relation to these pathological conditions.
基金supported by the National Key Research and Development Program of China,No.2022YFC2703101(to YC)the National Natural Science Fundation of China,No.82371422(to YC)+1 种基金the National Innovation and Entrepreneurship Training Program for College Students,No.202310611408(to XW)the 1·3·5 Project for Disciplines of Excellence Clinical Research Fund,West China Hospital,Sichuan University,No.2023HXFH032(to YC)。
文摘Motor neuron diseases are sporadic or inherited fatal neurodegenerative conditions.They selectively affect the upper and/or lower motor neurons in the brain and spinal cord and feature a slow onset and a subacute course contingent upon the site of damage.The main types include amyotrophic lateral sclerosis,progressive muscular atrophy,primary lateral sclerosis,and progressive bulbar palsy,the pathological processes of which are largely identical,with the main disparity lying in the location of the lesions.Amyotrophic lateral sclerosis is the representative condition in this group of diseases,while other types are its variants.Hence,this article mainly focuses on the advancements and challenges in drug research for amyotrophic lateral sclerosis but also briefly addresses several other important degenerative motor neuron diseases.Although the precise pathogenesis remains elusive,recent advancements have shed light on various theories,including gene mutation,excitatory amino acid toxicity,autoimmunology,and neurotrophic factors.The US Food and Drug Administration has approved four drugs for use in delaying the progression of amyotrophic lateral sclerosis:riluzole,edaravone,AMX0035,and tofersen,with the latter being the most recent to receive approval.However,following several phaseⅢtrials that failed to yield favorable outcomes,AMX0035 has been voluntarily withdrawn from both the US and Canadian markets.This article presents a comprehensive summary of drug trials primarily completed between January 1,2023,and June 30,2024,based on data sourced from clinicaltrials.gov.Among these trials,five are currently in phaseⅠ,seventeen are in phaseⅡ,and eleven are undergoing phaseⅢevaluation.Notably,24 clinical trials are now investigating potential disease-modifying therapy drugs,accounting for the majority of the drugs included in this review.Some promising drugs being investigated in preclinical studies,such as ATH-1105,are included in our analysis,and another review in frontiers in gene therapy and immunotherapy has demonstrated their therapeutic potential for motor neuron diseases.This article was written to be an overview of research trends and treatment prospects related to motor neuron disease drugs,with the aim of highlighting the latest potentialities for clinical therapy.
文摘Deep brain stimulation(DBS)is an established therapeutic intervention for people with Parkinson’s disease(PwPD)and is increasingly being utilized for other neurological disorders.Although effective in alleviating motor symptoms and reducing medication requirements,DBS has undergone minimal conceptual evolution and still relies on continuous high-frequency electrical stimulation.In Parkinson’s disease(PD),this persistent stimulation may cause adverse effects,including dysarthria,stimulation-induced dyskinesia,impulsivity,and mood alterations.Additionally,the continuous energy demand of current DBS systems accelerates battery depletion,necessitating more frequent battery charging or battery replacement surgeries,increasing risks,burden,and costs.Basic neuroscience research has long demonstrated that exogenous electrical stimulation can induce persistent changes to synaptic connections,known as long-term plasticity.
基金National Institute of Health(NIH)National Institute of Neurological Disorders and Stroke(NINDS),Nos.NS112910,NS133252(to BD)Department of Defense(DoD)Peer Reviewed Medical Research Program(PRMRP)Discovery Award,No.W81XWH2010186(to BD).
文摘The generation of human induced pluripotent stem cell-derived motor neurons overcomes limited access to human tissues and offers an unprecedented approach to modeling motor neuron diseases such as dystonia and amyotrophic lateral sclerosis.Motor neurons generated through different strategies may exhibit substantial differences in purity,maturation,characterization,and even neuronal identity,leading to variable outcomes in disease modeling and drug screening.However,very few comparative studies have been conducted to determine the similarities and differences among motor neurons prepared via different protocols.In this study,we prepared human induced pluripotent stem cell-derived motor neurons via lentiviral delivery of transcription factors and chemical induction and performed a systematic comparative analysis.We found that motor neurons generated by both approaches showed typical motor neuron morphology and robustly expressed motor neuron-specific markers,such as nuclear homeobox transcription factor 9 and choline acetyltransferase.The chemical induction protocol utilizes a combination of small molecules to induce motor neuron differentiation,offering a significantly faster maturation time of 35 days compared to 46 days with lentiviral delivery of transcription factors.Additionally,while lentiviral delivery of transcription factors are suitable for downstream biochemical analysis,chemical induction are more applicable for therapeutic approaches as they avoid the use of lentiviruses.Both approaches produce motor neurons with high purity(>95%)and yield.No significant differences were found between chemical induction and lentiviral delivery of transcription factors in terms of motor neuron markers and maturation markers.These robust methodologies offer researchers powerful tools for investigating motor neuron diseases and potential therapeutic strategies.
文摘Purpose:This study examined potential differences in strength,muscle morphology,and motor unit(MU)behavior of the abductor digiti minimi(ADM)between normal-fat(NF)and over-fat(OF)males.Methods:Dual-energy X-ray absorptiometry assessed percent body fat(%BF).Ultrasonography determined muscle cross-sectional area(CSA),echo intensity(EI),and subcutaneous fat(s FAT).MU behavior was assessed during isometric muscle actions at 50%of maximal voluntary contraction(MVC)by analyzing the y-intercepts and slopes for the MU action potential amplitude(MUAPAMP)vs.recruitment threshold(RT)relationships,the A and B terms for the mean firing rate(MFR)vs.RT relationships,and normalized electromyographic amplitude(N-EMGRMS).MU firing times and waveforms were validated with reconstruct-and-test and spike trigger average procedures.Results:%BF was greater for OF(25.70%±5.40%)than NF(16.50%±2.20%;p<0.001).MVC was greater for NF(27.13±7.16)N than OF([19.89±4.96]N;p=0.014).CSA was greater for NF(2.48±0.39)cm^(2)than OF([1.95±0.47]cm^(2);p=0.011).The y-intercepts for the MUAPAMPvs.RT relationships were greater for NF(0.283±0.254)m V than OF([-0.221±0.659]m V;p=0.004).The B terms for the MFR vs.RT relationships were greater for NF(-0.024±0.003)pps/%MVC than OF([-0.031±0.009]pps/%MVC;p=0.038).N-EMGRMSwas similar between groups(p=0.463).Conclusion:Maximal strength,muscle size,and MU recruitment and firing rate patterns for a non-weight bearing muscle differed between normal-fat and over-fat males.
文摘This paper proposes a collaborative design method for enhancing the power factor and torque of electric motors.First,the intrinsic relationship between flux linkage analysis of the permanent magnet(PM)and armature field and the power factor is explored.Then,the connection between flux linkage and harmonics is established,clarifying the mechanism for improving power factor and torque.Improvements are focused on the PM and permeance.Regarding the PM structure,employing a Y-shaped PM structure effectively increases PM utilization,reduces leakage flux at the outer ends,and enhances the PM flux linkage.Concerning permeance,stator tooth design is optimized to cooperatively improve permeance harmonics,reduce the non-working flux linkage of the armature field,and enhance the fundamental modulation wave of the armature field responsible for torque generation.This improves the power factor while maintaining motor torque.Finally,through PM structural design,the motor torque performance is optimized.Furthermore,the performance of the Y-shaped PM motor is evaluated.A prototype was manufactured and tested.Theoretical analysis and experimental results demonstrate the effectiveness of the proposed method to a significant extent.
基金supported by the Henan Provincial Key Research and Development Special Project(251111220200)Natural Science Foundation of Henan Province Project(252300420446).
文摘To explore the distribution law of the temperature field in the motor pump and the influence of the fanshaped DC channel with spoiler in the pump housing on its heat dissipation performance.This study takes the arc-gear type hydraulicmotor pump as the research object.In COMSOL,a coupled heat transfer simulationmodel of themotor pump’s fluid-solid coupling is established,and the internal temperature field characteristics are analyzed.To improve the heat dissipation effect of the motor pump,it is proposed to arrange spoiler in the fan-shaped DC channel of the pump housing to enhance heat dissipation.Three types of spoilers,namely,wing-shaped,inclined rectangle-shaped,and wave-shaped,are designed.The simulation results show that when the motor pump operates under rated conditions,due to the poor heat dissipation environment inside the motor pump,the high-temperature areas of the motor pump are concentrated in the rotor and permanent magnet parts.After arranging the spoiler,the turbulent kinetic energy and vorticity in the fan-shaped DC channel of the pump housing are significantly enhanced.All three spoiler structures can reduce the maximum temperature of each component of the motor.According to the comprehensive performance evaluation criterion(PEC),the inclined rectangle-shaped structure has the best comprehensive heat transfer performance(PEC=1.114),while the wave-shaped structure has higher heat transfer efficiency but greater pressure loss.The wing-shaped structure has relatively limited enhancement effect on heat dissipation.This study systematically quantifies the influence of different spoiler structures on heat dissipation performance and flowresistance characteristics,providing a solution for enhancing the heat dissipation of the motor pump.
基金supported in part by the National Natural Science Foundation of China under Grant 62172368the Natural Science Foundation of Zhejiang Province under Grant LR22F020003.
文摘The development of brain-computer interfaces(BCI)based on motor imagery(MI)has greatly improved patients’quality of life with movement disorders.The classification of upper limb MI has been widely studied and applied in many fields,including rehabilitation.However,the physiological representations of left and right lower limb movements are too close and activated deep in the cerebral cortex,making it difficult to distinguish their features.Therefore,classifying lower limbs motor imagery is more challenging.In this study,we propose a feature extraction method based on functional connectivity,which utilizes phase-locked values to construct a functional connectivity matrix as the features of the left and right legs,which can effectively avoid the problem of physiological representations of the left and right lower limbs being too close to each other during movement.In addition,considering the topology and the temporal characteristics of the electroencephalogram(EEG),we designed a temporal-spatial convolutional network(TSGCN)to capture the spatiotemporal information for classification.Experimental results show that the accuracy of the proposed method is higher than that of existing methods,achieving an average classification accuracy of 73.58%on the internal dataset.Finally,this study explains the network mechanism of left and right foot MI from the perspective of graph theoretic features and demonstrates the feasibility of decoding lower limb MI.
基金co-supported by the Fundamental Research Funds for Central Universities,China(No.3072024XX0206)the Natural Science Foundation of Heilongjiang Province,China(No.LH2024E069)。
文摘A surface pyrolysis and gas-phase combustion of the Ammonium Perchlorate(AP)/Hydroxy Terminated Polybutadiene(HTPB)composite propellant reaction kinetic mechanism with five-step chemical reaction is adopted.The effects of helium injection on the burning rate and combustion of AP/HTPB propellant are analyzed in details,and the characteristics of motor performance are obtained.The numerical simulation results demonstrate that helium injection enhances the combustion chamber pressure,thereby increasing the burning rate of propellant.However,the primary combustion reaction of the AP/HTPB propellant takes place within a thin layer on the burning surface,so the low-temperature helium has minimal impact on the gasphase combustion.Ultimately,the helium not only elevates the nozzle exit velocity,resulting in specific impulse gain,but also reduces the exhaust plume temperature.With an increase of helium mass flow rate,the area of the velocity increase zone at the nozzle exit continuously decreases,but the average velocity in the motor exit continuously increases.Overall,when the helium flow rate is 2.5 kg/s,the specific impulse can reach 10.5%.Reducing the helium injection hole diameter enhances mixing of helium and combustion gas and expands the velocity increase zone,thereby maximizing the exit velocity gain in average velocity at the nozzle exit.When the injection hole diameter is reduced from 100 mm to 20 mm,the specific impulse gain increases from 3.1%to 10.6%.Furthermore,increasing helium injection temperature greatly boosts the velocity of the mixed gas with the same helium mass fraction ultimately improving specific impulse.
文摘The increasing global prevalence of mild cognitive impairment(MCI)necessitates a paradigm shift in early detection strategies.Conventional neuropsychological assessment methods,predominantly paper-and-pencil tests such as the Mini-Mental State Examination and the Montreal Cognitive Assessment,exhibit inherent limitations with respect to accessibility,administration burden,and sensitivity to subtle cognitive decline,particularly among diverse populations.This commentary critically examines a recent study that champions a novel approach:The integration of gait and handwriting kinematic parameters analyzed via machine learning for MCI screening.The present study positions itself within the broader landscape of MCI detection,with a view to comparing its advantages against established neuropsychological batteries,advanced neuroimaging(e.g.,positron emission tomography,magnetic resonance imaging),and emerging fluid biomarkers(e.g.,cerebrospinal fluid,blood-based assays).While the study demonstrates promising accuracy(74.44%area under the curve 0.74 with gait and graphic handwriting)and addresses key unmet needs in accessibility and objectivity,we highlight its cross-sectional nature,limited sample diversity,and lack of dual-task assessment as areas for future refinement.This commentary posits that kinematic biomarkers offer a distinctive,scalable,and ecologically valid approach to widespread MCI screening,thereby complementing existing methods by providing real-world functional insights.Future research should prioritize longitudinal validation,expansion to diverse cohorts,integration with multimodal data including dual-tasking,and the development of highly portable,artificial intelligence-driven solutions to achieve the democratization of early MCI detection and enable timely interventions.
基金funded by Princess Nourah bint Abdulrahman University Researchers Support-ing Project number(PNURSP2026R346)Princess Nourah bint Abdulrahman University,Riyadh,Saudi Arabia.
文摘Motor imbalance is a critical failure mode in rotating machinery,potentially causing severe equipment damage if undetected.Traditional vibration-based diagnostic methods rely on direct sensor contact,leading to installation challenges and measurement artifacts that can compromise accuracy.This study presents a novel radar-based framework for non-contact motor imbalance detection using 24 GHz continuous-wave radar.A dataset of 1802 experimental trials was sourced,covering four imbalance levels(0,10,20,30 g)across varying motor speeds(500–1500 rpm)and load torques(0–3 Nm).Dual-channel in-phase and quadrature radar signals were captured at 10,000 samples per second for 30-s intervals,preserving both amplitude and phase information for analysis.A multi-domain feature extraction methodology captured imbalance signatures in time,frequency,and complex signal domains.From 65 initial features,statistical analysis using Kruskal–Wallis tests identified significant descriptors,and recursive feature elimination with Random Forest reduced the feature set to 20 dimensions,achieving 69%dimensionality reduction without loss of performance.Six machine learning algorithms,Random Forest,Extra Trees Classifier,Extreme Gradient Boosting,Categorical Boosting,Support Vector Machine with radial basis function kernel,and k-Nearest Neighbors were evaluated with grid-search hyperparameter optimization and five-fold cross-validation.The Extra Trees Classifier achieved the best performance with 98.52%test accuracy,98%cross-validation accuracy,and minimal variance,maintaining per-class precision and recall above 97%.Its superior performance is attributed to its randomized split selection and full bootstrapping strategy,which reduce variance and overfitting while effectively capturing the nonlinear feature interactions and non-normal distributions present in the dataset.The model’s average inference time of 70 ms enables near real-time deployment.Comparative analysis demonstrates that the radar-based framework matches or exceeds traditional contact-based methods while eliminating their inherent limitations,providing a robust,scalable,and noninvasive solution for industrial motor condition monitoring,particularly in hazardous or space-constrained environments.
基金supported by the European Research Council(ERC)under the European Union’s Horizon 2020 Research and Innovation Programme,No.810346.
文摘Stroke and traumatic brain injury lead to upper motor neuron syndrome,which is characterized by muscle spasticity or paresis of varying severity depending on the lesion’s location and extent.Current treatments are mostly symptomatic with limited efficacy and significant side effects.Nerve transfer techniques,such as the contralateral L4 ventral root transfer in animal models and C7 root transfer in both animal and clinical studies,have been shown to reduce spasticity and improve function in upper motor neuron syndrome;however,they lack selectivity.Our hypothesis is that using a selective peripheral donor nerve from the contralateral side,rather than the entire nerve root,may represent an effective nerve transfer and provide a robust basis for future research on selective muscle reinnervation in upper motor neuron syndrome.Ten rats underwent a contralateral ulnar-to-ulnar nerve transfer procedure.Electrophysiological measurements were conducted twelve weeks post-surgery to assess successful reinnervation of the contralateral flexor carpi ulnaris muscle.Additionally,muscle biopsies of the reinnervated flexor carpi ulnaris were harvested to examine the muscle fiber type composition,cross-sectional area,and collagen content as well as compare them to naive counterparts.Axon quantification of the reinnervated nerves was also performed.All rats recovered uneventfully,maintaining the use of both paws post-surgery.Electrophysiological tests confirmed the successful reinnervation of the flexor carpi ulnaris muscle.Muscle fiber type composition,cross-sectional area,and collagen content did not show statistically significant changes.Axon counts indicated successful nerve regeneration without architectural disruption.In conclusion,we were able to demonstrate this novel contralateral nerve transfer model’s feasibility,reproducibility,and safety as well as achieve effective muscle reinnervation.This model provides a valuable tool for further research on selective muscle reinnervation and treatment of upper motor neuron syndrome,with potential implications for improving clinical outcomes in stroke and traumatic brain injury patients.
基金supported in part by the National Natural Science Foundation of China under Grant 52177051in part by the Postgraduate Research and Practice Innovation Program of Jiangsu Province under Grant SJCX25_2046in part by the Key Research Project of Basic Science(Natural Science)in Jiangsu Province under Grant 24KJA470005.
文摘Owing to the multi-degree-of-freedom characteristics and inherent fault-tolerant capacity,six-phase motors have been widely adopted in high-power applications,such as electric vehicle propulsion and aerospace systems.This paper presents the fault-tolerant control strategy of symmetrical six-phase permanent magnet synchronous motor(SSPMSM)under an isolated neutral point topology and proposes a fault diagnosis scheme based on joint diagnosis of multiple variables.First,two mathematical models of SSPMSM and their relationship are established.Subsequently,the current vectors in the torque subspace and harmonic subspace of the two winding sets under fault conditions are analyzed,and the cause of post-fault torque ripple is explained as resulting from controller conflict.In addition,a multivariate fault diagnosis scheme based on voltage threshold in the x-y subspace and current trajectory characteristics in theα-βsubspace is proposed to enhance the diagnostic accuracy.Finally,the feasibility and stability of the proposed control and diagnosis methods are verified by experiments.
基金supported by Craig H.Neilsen Foundation,Wings for Life Foundation,Canadian Institutes of Health Research,and Fonds de Recherche Québec-Santé(to FB).
文摘Spinal cord injury(SCI)interrupts the flow of information between the brain and the spinal cord,thus leading to a loss of sensory information and motor paralysis of the body below the lesion.Surprisingly,most SCIs are incomplete and spare supraspinal pathways,especially those located within the peripheral white matter of the spinal cord,which includes reticulospinal pathways originating from the medullary reticular formation.Whereas there is abundant literature about the motor cortex,its corticospinal pathway,and its capacity to modulate functional recovery after SCI,less is known about the medullary reticular formation and its reticulospinal pathway.
