Motor System Research Articles

An Overview of Epigenetic Changes in the Parkinson's Disease Brain.

Parkinson's disease is a progressive neurodegenerative disorder, predominantly of the motor system. Although some genetic components and cellular mechanisms of Parkinson's have been identified, much is still unknown. In recent years, emerging evidence has indicated that non-DNA-sequence variation (in particular epigenetic mechanisms) is likely to play a crucial role in the development and progression of the disease. Here, we present an up-to-date overview of epigenetic processes including DNA methylation, DNA hydroxymethylation, histone modifications and non-coding RNAs implicated in the brain of those with Parkinson's disease. We will also discuss the limitations of current epigenetic research in Parkinson's disease, the advantages of simultaneously studying genetics and epigenetics, and putative novel epigenetic therapies.

Period-1 Motions and Bifurcations of a 3D Brushless DC Motor System with Voltage Disturbance

Abstract: In this paper, the nonlinear dynamic system of a brushless DC motor with voltage disturbance is studied analytically via a generalized harmonic balance method. A truncated Fourier series with time-varying coefficients is utilized to represent the analytical variations of nonlinear currents and voltages within this dynamic system. Bifurcations of periodic currents and voltages are obtained, and their stability is discussed through eigenvalue analysis. The frequency–amplitude characteristics of periodic currents and voltages exhibit complexity in the frequency domain. Comparative illustrations are provided to contrast the analytical solutions with numerical outcomes for periodic currents and voltages. These analytical findings can be effectively employed for controlling the brushless DC motors experiencing voltage disturbances.

Construction and Experimental Research of Active Vibration Control System of Voice Coil Motor with Integral Acceleration Feedback

Abstract The skyhook control technology is widely used in active vibration isolation and has proven effective. However, the absolute speed sensor used in the skyhook control technology is easily affected by external factors and may be easily damaged. There are few application scenarios for the skyhook control technology. To overcome this limitation, a brand-new approach is proposed for the design of an isolator that involves a voice coil motor (VCM) and an accelerometer. First of all, the proposed structure is introduced, and the dynamic model is established to achieve an analytical solution. Then, an integral acceleration feedback (IAF) algorithm is introduced and simulations are carried out. Finally, a prototype is constructed to verify its vibration isolation performance. From the experimental results, it can be concluded that the proposed active vibration control system (AVCS) can effectively reduce the peak value near the natural frequency, with a peak value reduction of 14.77 dB. Compared with the simulation results, the peak change rate at 12.5 Hz is 3.92%. AVCS with IAF can be applied to more application scenarios with a similar isolation effect to skyhook control technology.

ANFIS-based optimisation for achieving the maximum torque per ampere in induction motor drive with conventional PI

This research presents an innovative approach to controlling the speed of an induction motor drive by utilizing a combination of neural networks and fuzzy inference systems (ANFIS). The study focuses on computing the rotor's magnetic flux while considering different overshoot and settling criteria for torque and motor speed. The goal is to optimize torque per ampere and generate the necessary torque. The proposed ANFIS-based torque-per-ampere control technique offers a distinctive method applicable to a static induction motor model. This method allows for an increase in stator current while maintaining flexibility and individuality in motor control strategies. It compares various motor vector control methods, specifically focusing on strategies to reduce torque ripple. These strategies include adaptive ANFIS, fuzzy logic control (FLC), and proportional-integral (PI) control. The research highlights the effectiveness of an adaptive ANFIS controller in achieving the most significant reduction in torque ripple within the induction motor system. This proposed problem identification sets the stage for exploring and developing solutions to enhance the performance and efficiency of induction motor drives.

Torque balance control of underwater dual-motor system

Abstract The duocentric motor drive system is commonly employed in various fields such as the printing and dyeing paper industry and industrial production. As one of the dual-motor systems, the duocentric motor system sometimes causes torque imbalance due to sudden load changes during underwater operation. This imbalance seriously affects the coordinated operation of the duocentric motor system. Addressing these issues, this paper proposes a control approach utilizing a combination of speed and torque control to manage the duocentric motor system. Through simulation, this control technique is validated to enhance the operation capability of the duocentric motor while ensuring system stability and reliability.

Four Quadrant Operation of DC Motor Controlled by Android Application

Abstract: The project is designed to develop a four quadrant speed control system for a DC motor. The motor is operated in four quadrants i.e. clockwise; counter clock-wise, forward brake and reverse brake. It also has a feature of speed control. The four quadrant operation of the dc motor is best suited for industries where motors are used and as per requirement as they can rotate in clockwise, counter-clockwise and also apply brakes immediately in both the directions. In case of a specific operation in industrial environment, the motor needs to be stopped immediately. In such scenario, this proposed system is very apt as forward brake and reverse brake are its integral features. Instantaneous brake in both the directions happens as a result of applying a reverse voltage across the running motor for a brief period and the speed control of the motor can be achieved with the PWM pulses generated by the microcontroller. The microcontroller used in this project is from 8051 family. Remote operation is achieved by any smart-phone/Tablet etc., with Android OS, upon a GUI (Graphical User Interface) based touch screen operation. Bluetooth device is provided to connect with android application device for the operation of the motor which are interfaced to the microcontroller that provides an input signal to it and in turn controls the speed of the motor through a motor driver IC. This project can be enhanced by using higher power electronic devices to operate high capacity DC motors. Regenerative braking for optimizing the power consumption can also be incorporated

Hollow microsphere-reinforced ablative materials for thermal protection systems of solid rocket motors

The rapid development of large heavy-duty solid rockets has placed increasing demands on the density and ablation resistance of thermal protection system (TPS) materials. Hollow microspheres (HMs) are promising reinforcing materials. However, HMs break under mechanical extrusion during material preparation, which limits their development into high-performance TPS materials. In this study, a novel preparation scheme was designed for low-damage TPS materials. High-strength HMs were selected to reduce their breakage. Moreover, a TPS material with low density and excellent ablation resistance was developed. The density reduction of the HM formulation was considerably higher than that reported in other studies. This study addressed the problem of easy HM breakage during material preparation. Consequently, HM-reinforced TPS materials with low density and excellent ablation resistance were developed to help reduce the negative mass and improve the comprehensive performance of solid rocket motors.

Development of Interactive Media for Hybrid Motor System in Strengthening Industrial Skills in Vocational High School

Development of Interactive Media for Hybrid Motor System in Strengthening Industrial Skills in Vocational High School

Research on the configuration design and energy management of a novel plug-in hybrid electric vehicle based on the double-rotor motor and hybrid energy storage system

Aiming at the problems of conventional plug-in hybrid electric vehicle (PHEV), a novel PHEV configuration called DH-PHEV is proposed based on double-rotor motor (DRM) and hybrid energy storage system (HESS). For improving the comprehensive efficiency and reducing the charging/discharging rate of battery, the comprehensive energy management strategy (CEMS) is studied. Firstly, a rule-based torque allocation strategy is proposed based on the DH-PHEV configuration, the DRM operating characteristics, and the HESS operating states. The torque allocation of DRM is optimized based on the sequential quadratic programming. Secondly, the power allocation between battery and supercapacitor is optimized based on the dynamic programming (DP), with the goal of reducing the charging/discharging rate of battery and minimizing the energy consumption. The CEMS for DH-PHEV is proposed based on the DP optimization results and DRM torque allocation. Finally, the feasibility and adaptability of DH-PHEV configuration and CEMS are verified. The results show that the adaptability of CEMS under different driving cycles is excellent, and the operating modes are reasonable. The comprehensive efficiency and the charging/discharging rate of battery are optimized effectively. Under 6 WLTCs and 16 actual vehicle driving cycles, the pure electric driving range for DH-PHEV is improved by 1.07 % and 4.36 %, respectively.

Current implications of EEG and fNIRS as functional neuroimaging techniques for motor recovery after stroke

Abstract Persistent motor deficits are highly prevalent among post-stroke survivors, contributing significantly to disability. Despite the prevalence of these deficits, the precise mechanisms underlying motor recovery after stroke remain largely elusive. The exploration of motor system reorganization using functional neuroimaging techniques represents a compelling yet challenging avenue of research. Quantitative electroencephalography (qEEG) parameters, including the power ratio index, brain symmetry index, and phase synchrony index, have emerged as potential prognostic markers for overall motor recovery post-stroke. Current evidence suggests a correlation between qEEG parameters and functional motor outcomes in stroke recovery. However, accurately identifying the source activity poses a challenge, prompting the integration of EEG with other neuroimaging modalities, such as functional near-infrared spectroscopy (fNIRS). fNIRS is nowadays widely employed to investigate brain function, revealing disruptions in the functional motor network induced by stroke. Combining these two methods, referred to as integrated fNIRS-EEG, neural activity and hemodynamics signals can be pooled out and offer new types of neurovascular coupling-related features, which may be more accurate than the individual modality alone. By harnessing integrated fNIRS-EEG source localization, brain connectivity analysis could be applied to characterize cortical reorganization associated with stroke, providing valuable insights into the assessment and treatment of post-stroke motor recovery.

Narrative analysis in individuals with Parkinson's disease following intensive voice treatment: secondary outcome variables from a randomized controlled trial.

Communication is often impaired in individuals with Parkinson's disease (PD), typically secondary to sensorimotor deficits impacting voice and speech. Language may also be diminished in PD, particularly for production and comprehension of verbs. Evidence exists that verb processing is influenced by motor system modulation suggesting that verb deficits in PD are underpinned by similarities in the neural representations of actions that span motor and semantic systems. Conversely, subtle differences in cognition in PD may explain difficulty in processing of complex syntactic forms, which increases cognitive demand and is linked to verb use. Here we investigated whether optimizing motor system support for vocal function (improving loudness) affects change in lexical semantic, syntactic, or informativeness aspects of spoken discourse. Picture description narratives were compared for 20 Control participants and 39 with PD, 19 of whom underwent Lee Silverman Voice Treatment (LSVT LOUD®). Treated PD narratives were also contrasted with those of untreated PD and Control participants at Baseline and after treatment. Controls differed significantly from the 39 PD participants for verbs per utterance, but this difference was largely driven by untreated PD participants who produced few utterances but with verbs, inflating their verbs per utterance. Given intervention, there was a significant increase in vocal loudness but no significant changes in language performance. These data do not support the hypothesis that targeting this speech motor system results in improved language production. Instead, the data provide evidence of considerable variability in measures of language production across groups, particularly in verbs per utterance.

Social and Communication Development in Infants with Isolated Agenesis of the Corpus Callosum

ObjectiveTo evaluate the development of social behavior, communication, emotion regulation, and repetitive behaviors in infants with congenital malformation of the corpus callosum, specifically those with isolated Agenesis of the Corpus Callosum (ACC) in comparison to typically developing infants. Study DesignThis case-control longitudinal observation study examined parent report of social behavior, social-communication, emotion regulation, and repetitive behavior development in community ascertained infants (n = 156) and infants with isolated ACC (n = 57) between 12 and 24 months of age. ResultsInfants with isolated ACC produced fewer words at 12- (p = 0.003) 18- (p < 0.001), and 24-months of age (p = 0.003), and fewer gestures at 12- (p < 0.001), 18- (p < 0.001), and 24-months of age (p < 0.001). In addition, the ACC group demonstrated delays in reciprocal social behavior at 18-months (p = 0.01) and social competence at 12- (p < 0.001) and 18-months (p = 0.01). No concerns were noted in emotion regulation or restricted and repetitive behavior and social behavior appears to normalize at 24 months. ConclusionsExisting data suggests heterogeneity in developmental outcomes among individuals with isolated ACC. The current findings fill a gap in knowledge about development in the second year of life. Surveillance of social and communication ability in infants with ACC may be warranted. The role of the corpus callosum in facilitating rapid interhemispheric information processing impacts skills beyond the motor system. More work is needed to identify intervention targets for infants and toddlers with ACC.

A multimodal approach to automated hierarchical assessment of bulbar involvement in amyotrophic lateral sclerosis.

As a hallmark feature of amyotrophic lateral sclerosis (ALS), bulbar involvement leads to progressive declines of speech and swallowing functions, significantly impacting social, emotional, and physical health, and quality of life. Standard clinical tools for bulbar assessment focus primarily on clinical symptoms and functional outcomes. However, ALS is known to have a long, clinically silent prodromal stage characterized by complex subclinical changes at various levels of the bulbar motor system. These changes accumulate over time and eventually culminate in clinical symptoms and functional declines. Detection of these subclinical changes is critical, both for mechanistic understanding of bulbar neuromuscular pathology and for optimal clinical management of bulbar dysfunction in ALS. To this end, we developed a novel multimodal measurement tool based on two clinically readily available, noninvasive instruments-facial surface electromyography (sEMG) and acoustic techniques-to hierarchically assess seven constructs of bulbar/speech motor control at the neuromuscular and acoustic levels. These constructs, including prosody, pause, functional connectivity, amplitude, rhythm, complexity, and regularity, are both mechanically and clinically relevant to bulbar involvement. Using a custom-developed, fully automated data analytic algorithm, a variety of features were extracted from the sEMG and acoustic recordings of a speech task performed by 13 individuals with ALS and 10 neurologically healthy controls. These features were then factorized into 10 composite outcome measures using confirmatory factor analysis. Statistical and machine learning techniques were applied to these composite outcome measures to evaluate their reliability (internal consistency), validity (concurrent and construct), and efficacy for early detection and progress monitoring of bulbar involvement in ALS. The composite outcome measures were demonstrated to (1) be internally consistent and structurally valid in measuring the targeted constructs; (2) hold concurrent validity with the existing clinical and functional criteria for bulbar assessment; and (3) outperform the outcome measures obtained from each constituent modality in differentiating individuals with ALS from healthy controls. Moreover, the composite outcome measures combined demonstrated high efficacy for detecting subclinical changes in the targeted constructs, both during the prodromal stage and during the transition from prodromal to symptomatic stages. The findings provided compelling initial evidence for the utility of the multimodal measurement tool for improving early detection and progress monitoring of bulbar involvement in ALS, which have important implications in facilitating timely access to and delivery of optimal clinical care of bulbar dysfunction.

Composite control based on FNTSMC and adaptive neural network for PMSM system

In this paper, a novel fixed-time non-singular terminal sliding mode control (NFNTSMC) method with an adaptive neural network (ANN) is proposed for permanent magnet synchronous motor (PMSM) system to improve PMSM performance. For nominal PMSM system without disturbance, a novel fixed-time non-singular terminal sliding mode control is designed to achieve fixed-time convergence property to improve the dynamic performance of the system. However, parameters mismatch and external load disturbances generally exist in PMSM system, the controller designed by NFNTSMC requires a large switching gain to ensure the robustness of the system, which will cause high-frequency sliding mode chattering. Therefore, an adaptive radial basis function (RBF) neural network is designed to approximate the unknown nonlinear lumped disturbance including parameters mismatch and external load disturbances online, and then the output of the neural network can be compensated to the NFNTSMC controller to reduce the switching gain and sliding mode chattering. Finally, the fixed-time convergence property and stability of the system are proved by Lyapunov method. The simulation and experimental results show that the presented strategy possesses satisfactory dynamic performance and strong robustness for PMSM system. And the proposed control scheme also provides an effective and systematic idea of the controller design for PMSM.

Investigations of Sustainable Biodegradable Oil and Magnetic Particle‐Based Magnetorheological Fluid Dampers for Vibration Attenuation of a Rotor Dynamic System

This article aims to study the physical characterization and performance of a material‐based magnetorheological fluid (MRF) dampers for vibration attenuation of a high‐speed rotor–motor system near resonance. Four samples are synthesized by combining electrolytic iron and carbonyl iron (CI) with Castor and Karanja oil and experimentally investigated for their contribution to vibration attenuation. The results demonstrate effective vibration attenuation of the biodegradable oil‐based MRF damper than the nonbiodegradable oil‐based MRF damper. The best vibration attenuation is observed in the case of moderately viscous MRF. CI‐based samples exhibit a lower sedimentation rate, hence recommended for MRF. The vibration amplitude is maximum for the Castor oil‐based MRF damper, however, is minimum for the Karanja oil‐based MRF damper. The steady and transient results of vibration amplitudes are obtained and analyzed for different currents supplied to the MRF damper. The range of unstable speed near resonance is also obtained. The prepared samples show higher attenuation of 6–25% than Sample 5. The vibration amplitude attenuation of Sample 4 and Sample 5 are 47% and 22%, respectively. The findings of this study carry significant implications for controlling the vibration of the dynamic system using an eco‐friendly damping system.

Sliding mode observer-based fault diagnosis and continuous control set fault tolerant control for PMSM with demagnetization fault

A fault detection, estimation and fault tolerant control scheme for demagnetization fault in the permanent magnet synchronous motor systems is proposed in this paper. When demagnetization fault occurs, the system will deviate from the normal state severely. To facilitate the calculation, the demagnetization fault is converted to the dq coordinate system for processing and the resistance change is modeled as the system uncertainty, and the effect of the uncertainty on the system is analyzed. Then a fault detection observer is designed to detect the fault occurrence time, and a sliding mode observer based fault estimation algorithm is designed to estimate the fault and disturbance information. The observer parameters are determined by linear matrix inequality. When the fault information is obtained, a continuous control set fault tolerant control scheme is presented to minimize the impact of fault as far as possible. Finally, experimental results provide evidence of the feasibility of the suggested algorithm.

Timing-dependent synergies between motor cortex and posterior spinal stimulation in humans.

Volitional movement requires descending input from the motor cortex and sensory feedback through the spinal cord. We previously developed a paired brain and spinal electrical stimulation approach in rats that relies on convergence of the descending motor and spinal sensory stimuli in the cervical cord. This approach strengthened sensorimotor circuits and improved volitional movement through associative plasticity. In humans, it is not known whether posterior epidural spinal cord stimulation targeted at the sensorimotor interface or anterior epidural spinal cord stimulation targeted within the motor system is effective at facilitating brain evoked responses. In 59 individuals undergoing elective cervical spine decompression surgery, the motor cortex was stimulated with scalp electrodes and the spinal cord was stimulated with epidural electrodes, with muscle responses being recorded in arm and leg muscles. Spinal electrodes were placed either posteriorly or anteriorly, and the interval between cortex and spinal cord stimulation was varied. Pairing stimulation between the motor cortex and spinal sensory (posterior) but not spinal motor (anterior) stimulation produced motor evoked potentials that were over five times larger than brain stimulation alone. This strong augmentation occurred only when descending motor and spinal afferent stimuli were timed to converge in the spinal cord. Paired stimulation also increased the selectivity of muscle responses relative to unpaired brain or spinal cord stimulation. Finally, clinical signs suggest that facilitation was observed in both injured and uninjured segments of the spinal cord. The large effect size of this paired stimulation makes it a promising candidate for therapeutic neuromodulation. KEY POINTS: Pairs of stimuli designed to alter nervous system function typically target the motor system, or one targets the sensory system and the other targets the motor system for convergence in cortex. In humans undergoing clinically indicated surgery, we tested paired brain and spinal cord stimulation that we developed in rats aiming to target sensorimotor convergence in the cervical cord. Arm and hand muscle responses to paired sensorimotor stimulation were more than five times larger than brain or spinal cord stimulation alone when applied to the posterior but not anterior spinal cord. Arm and hand muscle responses to paired stimulation were more selective for targeted muscles than the brain- or spinal-only conditions, especially at latencies that produced the strongest effects of paired stimulation. Measures of clinical evidence of compression were only weakly related to the paired stimulation effect, suggesting that it could be applied as therapy in people affected by disorders of the central nervous system.

Speed Sensor-less Control of Induction Motor based on Super-helical Sliding Mold

Background: With the continuous progress of technology and the development of shield enterprises, higher requirements are put forward for speed estimation and system stability in the sensorless control system of induction motors in shield machines. Method: In order to solve the problems of velocity observation error and sliding mode vibration of the induction motor velocity observation method based on sliding mold observer, an improved superhelical sliding mold observer is proposed by combining the currently known invention patents and the information based on the induction motor control. Result: The open square of the current error value is introduced into the continuous function of the sliding variable of the observer, and two different functions are used in the boundary layer to replace the sign function, which reduces the sliding mode noise and vibration problems, and the stability of the observer is proved by the Lyapunov stability theory. After that, a phase-locked loop alternative model-referenced adaptive algorithm is used as the rotational speed observation link, which solves the problem that the conventional model-referenced adaptive algorithm relies on the current-modeled magnetic chain observer. Conclusion: The improved super-helical sliding mode observer and phase-locked loop control method effectively reduce the system vibration and speed estimation error of the motor under different speeds and loading conditions, and the observed currents are smoother, which improves the stability of the system. Simulation and experimental results under different working conditions show the effectiveness of the proposed method.

Функциональные резервы адаптации двигательной системы спортсменов с позиций физиолого-биомеханического подхода

Human adaptation to physical activity is manifested through mobilization of functional reserves. The purpose of this study was to provide a scientific and experimental substantiation of the adaptation of functional reserves of the motor system in athletes to specific sports activities from the standpoint of the physiological and biomechanical approach. Materials and methods. The study involved 704 elite athletes doing various sports. Reaction time was determined using the hardware and software package “Sports Psychophysiologist”. Stabilometric parameters were analysed using stabilometric platforms with the Smart BTS Motion System (BTS Bioengineering, Italy); the static analysis test protocol was applied. Electromyographic and biomechanical (kinematic and dynamic) movement control was performed using the Smart BTS Motion System as well. Functional reserves of the motor system were studied in line with the existing ideas about the components of the human body’s physiological reserves activated when doing sports. The following were evaluated: sensory systems (sensorimotor reactions, vestibular stability), movement control (stabilography, kinematics, dynamics), regulation of homeostasis, and implementation of activity (neuromuscular system). Results. We found that both single (in respect of urgent adaptation: an increase in voltage, optimization of kinematics and dynamics during a weightlifting snatch) and systematic (as regards long-term adaptation: improvement in reaction time and vestibular stability in athletes of various sports) training sessions involving maximum strength, power and speed contribute to the activation of the relevant sensory systems, central nervous system and muscular system, which form the basis of the motor system and increase its functionality as a whole.

Investigation of design methodology for doubly-fed bearingless flux reversal motor

This article integrates the technology of bearingless motors with the basic theory of magnetic flux reverse motors, proposes a doubly fed bearingless magnetic flux reverse motor, and conducts research on its structural design, operating mechanism, electromagnetic performance analysis, mathematical model, control method, digital control system, and other aspects. The basic structure of a new type of doubly fed bearingless magnetic flux reverse motor is designed, and the principle of radial suspension force generation is studied. The performance related to torque and radial suspension force is analyzed. A mathematical model of torque and radial suspension force is established, including magnetic field distribution, no-load permanent magnet flux, and no-load back electromotive force. A doubly fed bearingless magnetic flux reverse motor system is designed and constructed, and inductance experiments are conducted.