Motor Speed Changes Research Articles

A Rotor Position Detection Method for Permanent Magnet Synchronous Motors Based on Variable Gain Discrete Sliding Mode Observer

The purpose of this paper is to study the sensor-less rotor position estimation method for permanent magnet synchronous motors, and to achieve accurate estimation of rotor position in different conditions. Firstly, the traditional super-twisting observer algorithm is analyzed, and a new discrete variable gain sliding mode observer is designed to solve the buffeting problem in discrete systems, taking the reaction force as the disturbance signal. By estimating the back potential of the observer, the buffeting problem in the sliding mode algorithm can be effectively improved as shown by the simulation results. Then, to solve the problem of phase delay in rotor position estimation, an adaptive orthogonal phase-locked loop method is used to compensate the estimation error caused by the change in motor speed and increase the estimation accuracy of rotor position. The stability of the method can be proven by Lyapunov’s second method. Simulation experiments verify the accuracy of the proposed PMSM rotor position estimation method.

Design and Control of Upper Limb Rehabilitation Training Robot Based on a Magnetorheological Joint Damper.

In recent years, rehabilitation robots have been developed and used in rehabilitation training for patients with hemiplegia. In this paper, a rehabilitation training robot with variable damping is designed to train patients with hemiplegia to recover upper limb function. Firstly, a magnetorheological joint damper (MR joint damper) is designed for the rehabilitation training robot, and its structural design and dynamic model are tested theoretically and experimentally. Secondly, the rehabilitation robot is simplified into a spring-damping system, and the rehabilitation training controller for human movement is designed. The rehabilitation robot dynamically adjusts the excitation current according to the feedback speed and human-machine interaction torque, so that the rehabilitation robot always outputs a stable torque. The magnetorheological joint damper acts as a clutch to transmit torque safely and stably to the robot joint. Finally, the upper limb rehabilitation device is tested. The expected torque is set to 20 N, and the average value of the output expected torque during operation is 20.02 N, and the standard deviation is 0.635 N. The output torque has good stability. A fast (0.5 s) response can be achieved in response to a sudden motor speed change, and the average expected output torque is 20.38 N and the standard deviation is 0.645 N, which can still maintain the stability of the output torque.

Research on the Application of Machine Learning in the Real Time Decision System of Autonomous Vehicles

As human society enters the era of interconnection and intelligence; the rapid development of the automotive industry has made intelligent driving technology a new industry focus. This article conducts research on the application of machine learning in real-time decision-making systems for autonomous vehicles. The use of radial basis function artificial neural networks to solve the classification problem of overtaking intentions has been proven to be a universal approximator. Based on theoretical analysis and practical driving experience, it can be seen that driving behavior is often stimulated and influenced by multiple factors such as people, cars, roads, and the environment during the driving decision-making process. These factors are collectively referred to as driving decision influencing factors. Assist vehicle sensors in making decisions based on the identified signage information, accurately control the vehicle's driving route based on the identified lane markings, and improve the sensitivity of the sensors and the resilience of the entire system. Considering that the motor speed changes rapidly and in order to ensure stable transmission throughout the entire driving process, the system needs to be adjusted slowly, even if there is no small deviation adjustment, the adjustment speed is fast, and the large deviation generated during cornering or overtaking can be adjusted to prevent slow tracking response speed.

Prediction of Clean-room Air-conditioning Defects Using Deep Learning and a Differential Pressure Sensor

A clean room is used for adjusting the concentration of suspended particles using an air-conditioner. It has a fan-filter unit combining a centrifugal fan and a high-efficiency particulate air filter that purifies the outside air and directly affects its cleanliness. Defects in these systems are typically detected using special sensors for each fault, which can be costly. Therefore, this paper proposes a system for diagnosing defects in the fan-filter unit using a single differential sensor and deep learning. The fan-filter unit is part of the air-conditioning system, and it is usually defective in bearings, filters, and motors. These faults include ball wear, internal bearing contamination, filter contamination, and motor speed changes. Each defect was artificially induced in experiments, and the differential pressure data of each defect was learned using a long short-term memory (LSTM) deep learning algorithm. The results of deep learning experiments generated by randomly mixing data five times were presented using a confusion matrix, and the results showed an accuracy of 87.2±2.60%. Therefore, the possibility of diagnosing defects in the fan-filter unit using a single sensor was confirmed.

Improved Clamped Diode Based Z-Source Network for Three Phase Induction Motor

The 3Φ induction motor is a broadly used electric machine in industrial applications, which plays a vital role in industries because of having plenty of beneficial impacts like low cost and easiness but the problems like decrease in motor speed due to load, high consumption of current and high ripple occurrence of ripples have reduced its preferences. The ultimate objective of this study is to control change in motor speed due to load variations. An improved Trans Z Source Inverter (ΓZSI) with a clamping diode is employed to maintain constant input voltage, reduce ripples and voltage overshoot. To operate induction motor at rated speed, different controllers are used. The conventional Proportional-Integral (PI) controller suffers from high settling time and maximum peak overshoot. To overcome these limitations, Fractional Order Proportional Integral Derivative (FOPID) controller optimized by Gray Wolf Optimization (GWO) technique is employed to provide better performance by eliminating maximum peak overshoot problems. The proposed speed controller provides good dynamic response and controls the induction motor more effectively. The complete setup is implemented in MATLAB Simulation to verify the simulation results. The proposed approach provides optimal performance with high torque and speed along with less steady state error.

Age-Related Learning and Working Memory Impairment in the Common Marmoset.

Aging is the greatest risk factor for the development of neurodegenerative diseases, yet we still do not understand how the aging process leads to pathologic vulnerability. The research community has relied heavily on mouse models, but the considerable anatomic, physiological, and cognitive differences between mice and humans limit their translational relevance. Ultimately, these barriers necessitate the development of novel aging models. As a nonhuman primate (NHP), the common marmoset (Callithrix jacchus) shares many features in common with humans and yet has a significantly shorter lifespan (10 years) than other primates, making it ideally suited to longitudinal studies of aging. Our objective was to evaluate the marmoset as a model of age-related cognitive impairment. To do this, we used the Delayed Recognition Span Task (DRST) to characterize age-related changes in working memory capacity in a cohort of sixteen marmosets, of both sexes, varying in age from young adult to geriatric. These monkeys performed thousands of trials over periods of time ranging up to 50% of their adult lifespan. To our knowledge, this represents the most thorough cognitive profiling of any marmoset aging study conducted to date. By analyzing individual learning curves, we found that aged animals exhibited delayed onset of learning, slowed learning rate after onset, and decreased asymptotic working memory performance. These findings are not accounted for by age-related impairments in motor speed and motivation. This work firmly establishes the marmoset as a model of age-related cognitive impairment.SIGNIFICANCE STATEMENT Understanding the normal aging process is fundamental to identifying therapeutics for neurodegenerative diseases for which aging is the biggest risk factor. Historically, the aging field has relied on animal models that differ markedly from humans, constraining translatability. Here, we firmly establish a short-lived nonhuman primate (NHP), the common marmoset, as a key model of age-related cognitive impairment. We demonstrate, through continuous testing over a substantial portion of the adult marmoset lifespan, that aging is associated with both impaired learning and working memory capacity, unaccounted for by age-related changes in motor speed and motivation. Characterizing individual cognitive aging trajectories reveals inherent heterogeneity, which could lead to earlier identification of the onset of impairment, and extended timelines during which therapeutics are effective.

PMSM Current Harmonics Control Technique Based on Speed Adaptive Robust Control

Permanent magnet synchronous motor (PMSM) is widely used in electric vehicles due to its high power density. New requirements are constantly proposed with the development of PMSM, one of which is torque ripple. Current harmonic injection is a common method to minimize torque ripple. Designing effective controller to realize current harmonic injection is the key technology. In this paper, the transient voltage-current coupling equation considering magnetic saturation is derived by introducing incremental inductance. After appropriately simplifying, it is shown in form of the harmonic state space (HSS) equation. Considering that PMSM parameters varies with current due to magnetic saturation, robust controller is adopted to ensure stability. In order to eliminate the influence of motor speed change on control stability, the HSS is transformed into a spatial form. Then the speed adaptive robust (SAR) controller is designed. At last, the SAR controller is used in simulation and test bench experiment to verify dynamic response and stability. Compared with traditional PI and PR controller, the SAR controller can ensure good dynamic response, steady-state error and robust stability when speed and PMSM parameters vary. Moreover, SAR controller can well resist the harmonic coupling effect and system lag.

Preoperative Anemia and Risk for Perioperative Neurocognitive Dysfunction in Cardiac Surgery Patients: A Retrospective Analysis

To evaluate whether there is a relationship between preoperative anemia and domain-specific cognitive performance in patients undergoing cardiac surgery. Retrospective analysis of data collected from a randomized study. Tertiary care university hospital. A total of 436 patients age ≥55 years undergoing cardiac surgery. None. Neuropsychological testing was performed before and one month after surgery, using a standard battery. Individual Z-scores calculated from the mean and standard deviation of tests at baseline were combined into domain-specific scores. Anemia (hemoglobin <130 g/L for men, <120 g/L for women) was present in 41% of patients. Preoperative anemia had little impact on preoperative cognition. There were no differences in the change in cognitive performance one month after surgery from baseline between patients with and without preoperative anemia. However, in a sensitivity analysis using multiple imputation for missing cognitive test scores, significant associations were observed between preoperative anemia and change in postoperative processing speed (p=0.016), change in executive function (p=0.049), and change in fine motor speed (p=0.016). Nadir hemoglobin during cardiopulmonary bypass, which was lower in anemic than nonanemic patients, was associated with decrements in performance on tests of verbal fluency (p=0.007), processing speed (p=0.042), and executive function (p=0.10) one month after surgery but not delayed neurocognitive recovery (p=0.06). Preoperative anemia may be associated with impairment of selective cognitive domains after surgery. Any effect of preoperative anemia may have on cognition after surgery might be related to lower nadir hemoglobin during cardiopulmonary bypass.

Chimpanzees (Pan troglodytes) show subtle signs of uncertainty when choices are more difficult

Humans can tell when they find a task difficult. Subtle uncertainty behaviors like changes in motor speed and muscle tension precede and affect these experiences. Theories of animal metacognition likewise stress the importance of endogenous signals of uncertainty as cues that motivate metacognitive behaviors. However, while researchers have investigated second-order behaviors like information seeking and declining difficult trials in nonhuman animals, they have devoted little attention to the behaviors that express the cognitive conflict that gives rise to such behaviors in the first place. Here we explored whether three chimpanzees would, like humans, show hand wavering more when faced with more difficult choices in a touch screen transitive inference task. While accuracy was very high across all conditions, all chimpanzees wavered more frequently in trials that were objectively more difficult, demonstrating a signature behavior which accompanies experiences of difficulty in humans. This lends plausibility to the idea that feelings of uncertainty, like other emotions, can be studied in nonhuman animals. We propose to routinely assess uncertainty behaviors to inform models of procedural metacognition in nonhuman animals.

Brain functions and cognition on transient insulin deprivation in type 1 diabetes

BACKGROUNDType 1 diabetes (T1D) is a risk factor for dementia and structural brain changes. It remains to be determined whether transient insulin deprivation that frequently occurs in insulin-treated individuals with T1D alters brain function.METHODSWe therefore performed functional and structural magnetic resonance imaging, magnetic resonance spectroscopy, and neuropsychological testing at baseline and following 5.4 ± 0.6 hours of insulin deprivation in 14 individuals with T1D and compared results with those from 14 age-, sex-, and BMI-matched nondiabetic (ND) participants with no interventions.RESULTSInsulin deprivation in T1D increased blood glucose, and β-hydroxybutyrate, while reducing bicarbonate levels. Participants with T1D showed lower baseline brain N-acetyl aspartate and myo-inositol levels but higher cortical fractional anisotropy, suggesting unhealthy neurons and brain microstructure. Although cognitive functions did not differ between participants with T1D and ND participants at baseline, significant changes in fine motor speed as well as attention and short-term memory occurred following insulin deprivation in participants with T1D. Insulin deprivation also reduced brain adenosine triphosphate levels and altered the phosphocreatine/adenosine triphosphate ratio. Baseline differences in functional connectivity in brain regions between participants with T1D and ND participants were noted, and on insulin deprivation further alterations in functional connectivity between regions, especially cortical and hippocampus-caudate regions, were observed. These alterations in functional connectivity correlated to brain metabolites and to changes in cognition.CONCLUSIONTransient insulin deprivation therefore caused alterations in executive aspects of cognitive function concurrent with functional connectivity between memory regions and the sensory cortex. These findings have important clinical implications, as many patients with T1D inadvertently have periods of transient insulin deprivation.TRIAL REGISTRATIONClinicalTrials.gov NCT03392441.FUNDINGClinical and Translational Science Award (UL1 TR002377) from the National Center for Advancing Translational Science; NIH grants (R21 AG60139 and R01 AG62859); the Mayo Foundation.

Design and simulation studies of battery-supercapacitor hybrid energy storage system for improved performances of traction system of solar vehicle

Energy storage systems of Solar Vehicles require high energy density and high power density concurrently. The best solution is using supercapacitor (SC) during rapid power changes and in the recovery of braking energy to ameliorate solar vehicle autonomy. SCs can also keep batteries charged for extended durations and can be used to store the excess energy generated by photovoltaic panels. In this study, the power management of the electric traction system of the solar vehicle is insured by the hybridization of SCs and batteries to minimize the effects of peak current demands on the battery driving cycle. The efficiency of the overall system can be improved by the proposed hybrid storage system. The simulation results verify that integration of the SC into the photovoltaic energy storage system of the solar vehicle is effective in decreasing the battery stresses and eliminating the peak currents in the battery pack, thereby increasing the battery's life span. The use of SCs decreases the fluctuation in the direct current (DC) bus voltage during rapid motor speed changes and the photovoltaic fluctuations and provides a speed that is closest to the desired reference speed. A hardware design approach used for a small-scale prototype to proof the efficiency of the EMS and the distribution energy between batteries and SCs. It validated by three simulation tests.

Response to nicotine following overnight smoking abstinence during short-term progesterone treatment in women.

Preclinical and clinical literature suggest that sex hormones impact tobacco use behaviors in women. The goal of this double-blind crossover laboratory study was to examine the effect of oral exogenous progesterone (200 mg twice per day) versus placebo on nicotine response using measures of motor speed and cognitive function in women following overnight smoking abstinence. We hypothesized that increased progesterone would blunt the nicotine response whereby producing less change in motor speed and cognition in response to nicotine exposure. Female smokers, age 18-35, were randomized to participate in two 9-day crossover testing weeks. Participants completed a lab session following overnight abstinence where they were administered nicotine nasal spray and asked to complete measures of immediate memory (IMT), delayed memory (DMT), word recall (WR), and finger tapping speed (FT). After the first 9-day testing week, participants resumed smoking and returned the following month to complete the identical lab session in the crossover condition. Forty-seven women were included in this analysis (n = 47). We found no differences in the magnitude of response for IMT, DMT, and WR between conditions. For FT, women had a blunted response to nicotine during the placebo condition. When examining the association between hormone levels and relative performance, we found increases in DMT, WR, and FT but decreases in IMT during the progesterone condition. We observed differences between progesterone versus placebo in relative change in some measures of nicotine response following overnight abstinence. Future studies are needed to further characterize this response. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Induction motor sensorless control by DSP

This article presents the development of an algorithm for speed control of the induction motor by means of the DSP core microcontroller TMS320F28069M, which is in charge of performing the digital treatment of the voltage and current signals measured to estimate the speed of rotor and close the control loop. The algorithms consider the operating limits and the characteristics of the DSP, together with an interface that allows monitoring the estimated speed, and modifying the operating point and the constants of the PI controller, the controller output is assigned to an output of the DSP PWM_DAC which is connected to an ABB ACS800-U1 frequency converter in remote mode to carry out the motor speed change by means of a V / F control law.

Energy regeneration technique for electric vehicles driven by a brushless DC motor

The development of energy regeneration capability in electric vehicles can extend their driving range making them a competent alternative for conventional internal combustion engine vehicles. In this study, a novel energy regeneration technique, called a two-boost method, for electric vehicles driven by a brushless DC (BLDC) motor, a widely used motor in vehicular technology, is proposed. Based on this technique, the BLDC motor driver, which is selected to be a three-phase inverter, is converted into two simultaneous boost converters during energy regeneration periods in order to transfer energy from the BLDC motor into the battery and provide the braking force. Also, this method is compared with the single-boost method. The simulation and experimental results show that the amount of regenerated energy in this method is more than twice of that in the single-boost method. Moreover, it is observed that in the two-boost method, the motor speed changes linearly without any control of the electrical torque. In addition, since the amount of regenerated energy in this method as compared to the single-boost method is higher, the energy regeneration efficiency in this method is increased significantly.

Using a High-Speed Mini-PC to Control an Autonomous Underwater Vehicle

In this paper, the authors present the design of a mini-PC board to fast processing of an AUV (Autonomous Underwater Vehicle) with two 360° rotational thrusters. This rotation capability in the thrusters, along with an embedded mass shifter, allows for long-time immersive motor maneuvers for this AUV. Also, the conditions for moving the device at the water surface and depth are provided by changing the angle of the thrusters and moving the mass shifter along with the motor speed change. All the commands related to the motor angles, proper position of the thrusters, mass shifter, and speed, are sent to an Engine board via a high-speed Mini PC. The high-speed Mini PC sends decisions to the Engine board after receiving and processing all sensors data as well as data from embedded cameras. This integrated system provides the ability to move safely based on accurate analysis of the environment by sensors and images received by cameras from the surroundings, with minimal energy consumption for the underwater AUV. The results of various tests demonstrated the high performance of this AUV.

Efek Duty Cycle Pwm pada Pengendalian Kecepatan Motor BLDC 3 Phasa

Nowadays almost all electric convertible equipments are in motion using Brushless Direct Current (BLDC) motors, because BLDC motors have high efficiency and energy density because the lack of brush makes BLDC motors reliable enough, maintenance is cheap and can be used for high speed. This research is more emphasized on the controller unit using DRV 11873 IC which has EVM (Evaluation Module) as strong magnetic induction enhancer in BLDC motor winding (stator) with Pulse Width Modulation (PWM) duty cycle mode, the result of research shows the relationship between the addition of duty cycle PWM and the addition of a large supply voltage V (V) given to the 3 phase Phas motor BLDC to the motor speed change (RPM). Through the calculation of coefficient of determination (R2) each experimental results between the change of power supply voltage (V) to the speed (RPM) obtained 0.998 and the calculation of coefficient of determination (R2) change duty cycle PWM signal to the speed (RPM) 0.996.

Implementation of an Excitation Controller for an Impulse Motor-Generator

Three flywheel energy-stored impulse motor-generators (MGs) are used in the power supply system of HL-2A tokamak to produce short high-voltage or high-current pulse of desired parameters that are usually used for magnetic field coils and auxiliary heating equipment loads. The operation changing of these loads will cause disturbances in generator’s terminal voltage and the remarkable drop in MG’s rotating speed. This paper describes the implementation of an excitation controller using LabVIEW and CompactRIO for a 125-MVA impulse MG in power supply system of HL-2A/2M. Both a staged control strategy and digital PID algorithm built in LabVIEW are applied to the excitation controller that runs preciously in a 1-ms cycle to achieve voltage feedback control. The excitation controller, composed mainly of host computer and CompactRIO embedded reconfigurable system, is available to restore and stabilize terminal voltage in accordance with the desired voltage curves set by operators when pulsed loads and motor speed change quickly. It also implements real-time monitoring of the working condition and some electrical parameters of excitation system and communicates with central control system via Ethernet to either download discharge control files at time interval between two impulse discharges or upload waveform data generated in control process after a pulsed discharge. Engineering experiment results show that the use of excitation controller improves the voltage stiffness of the power supply system and provides the effective control of generator’s terminal voltage under the management of central control system.

Osmotaxis in Escherichia coli through changes in motor speed

Bacterial motility, and in particular repulsion or attraction toward specific chemicals, has been a subject of investigation for over 100 years, resulting in detailed understanding of bacterial chemotaxis and the corresponding sensory network in many bacterial species. For Escherichia coli most of the current understanding comes from the experiments with low levels of chemotactically active ligands. However, chemotactically inactive chemical species at concentrations found in the human gastrointestinal tract produce significant changes in E. coli's osmotic pressure and have been shown to lead to taxis. To understand how these nonspecific physical signals influence motility, we look at the response of individual bacterial flagellar motors under stepwise changes in external osmolarity. We combine these measurements with a population swimming assay under the same conditions. Unlike for chemotactic response, a long-term increase in swimming/motor speeds is observed, and in the motor rotational bias, both of which scale with the osmotic shock magnitude. We discuss how the speed changes we observe can lead to steady-state bacterial accumulation.

Design Characteristics of IPMSM With Wide Constant Power Speed Range for EV Traction

This paper presents study of design characteristics with wide constant power speed range (CPSR) for electric vehicle Propulsion. Through analysis of interior permanent magnet synchronous motor (IPMSM) control logic, design characteristic of extending CPSR is proposed. To achieve wide CPSR, center of voltage limit ellipse should be placed at cross point of current limit circle and d-axis. To analyze characteristic of voltage ellipse, four types of representative IPMSM rotor topologies are selected. Through rotor topology analysis, tendency of φ f and L ds parameters which decide center of voltage limit ellipse is analyzed. This paper also considers shifting of voltage limit ellipse center according to change in motor speed. Reflecting the result, this paper focuses on center of voltage limit ellipse position at maximum speed, because central coordinates of high-speed range determine characteristics of CPSR. Through the analysis result, this paper suggests direction of IPMSM design for wide CPSR.

Fault Tolerant Control Structure for Induction Motor Drive System

In this paper the Fault Tolerant (FT) vector controlled induction motor drive system is described and tested in various drive conditions. The influence of the rotor speed sensor faults on the properties of the analyzed drive are tested. Faults detection algorithms, based on different algorithms are developed and described. The results of the simulation carried out using the MATLAB/SimPowerSystem software are verified in experimental tests in MicroLabBox DS1202, in a wide range of motor speed changes. The proposed detection algorithms can be successfully applied in the Fault Tolerant Drive Systems (FTDS).