Robust position control of ultrasonic motor using VSS observer

Intrinsic properties of ultrasonic motor (high torque for low speed, high static torque, compact in size, etc.) offer great advantages for industrial applications. However, when load torque is applied, dead-zone occurs in control input. Therefore, sliding mode controller, which is a nonlinear controller, is adopted for ultrasonic motor. The state quantities, such as acceleration, speed, and position are needed to apply the sliding mode controller for position control. However, rotary encoder causes quantization errors in the speed information. This paper presents a robust position control method for ultrasonic motor by using Variable Structure System(VSS) observer. The state variables for sliding mode controller are estimated by the VSS observer. Besides, a small, low cost, and good response sliding mode controller is designed in this paper by using a micro computer that is essential in embedded system for the developments of industrial equipments. The effectiveness of the proposed method is verified by experimental results

Control of an Autonomous Hybrid Microgrid as Energy Source for a Small Rural Village

Nowadays, the exhaustion of electricity power in rural areas is becoming an important issue for many African Nations. Moreover, challenges include the high cost of extending the power grid to these locations, the economic health of the utilities and lack of revenue in impoverished villages. Numerous new initiatives are being implemented in the countries some of them co-financed by international organizations. In this paper, the hybrid microgrid is carried out as a feasible solution for a small rural village. A model of hybrid microgrid consisting of combination of photovoltaic (PV) panels and battery energy storage (BES) and a control system for managing the components of entire system to feed the village as local load is proposed. The control system must avoid the interruptions of power delivered to the consumers (village) and, therefore, good quality and reliability of system is required. The PI controllers are used to regulate the voltage and current using three-phase dq transformation, while the parameters are determined using Ziegler-Nichols tuning method. The effectiveness of the proposed method is verified by simulation results given by the Matlab/SimPowerSystems environment. 

Multi-energy Microgrids Incorporating EV Integration : Optimal Design and Resilient Operation

There are numerous opportunities and challenges in integrating multiple energy sources, for example, electrical, heat, and electrified transportation. The operation of multi-energy sources needs to be coordinated and optimized to achieve maximum benefits and reliability. To address the electrical, thermal, and transportation electrification energy demands in a sustainable and environmentally friendly multi-energy microgrid, this paper presents a mixed integer linear optimization model that determines an optimized blend of energy sources (battery, combined heat and power units, thermal energy storage, gas boiler, and photovoltaic generators), size, and associated dispatch. The proposed energy management system seeks to minimize total annual expenses while simultaneously boosting system resilience during extended grid outages, based on an hourly electrical and thermal load profile. This approach has been tested in a hospital equipped with an EV charging station in Okinawa, Japan through several case studies. Following a M1/M2/c queuing model, the proposed grid-tied microgrid successfully integrates EVs into the system and assures continued and economic power supply even during grid failures in different weather conditions.©2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.fi=vertaisarvioitu|en=peerReviewed

Robust position control of ultrasonic motor considering dead-zone

Intrinsic properties of ultrasonic motor (high torque for low speed, high static torque, compact in size, etc.) offer great advantages for industrial applications. However, when load torque is applied, dead-zone occurs in the control input. Therefore, a nonlinear controller, which considers dead-zone, is adopted for ultrasonic motor. The state quantities, such as acceleration, speed, and position are needed to apply the nonlinear controller for position control. However, rotary encoder causes quantization errors in the speed information. This paper presents a robust position control method for ultrasonic motor considering dead-zone. The state variables for nonlinear controller are estimated by a Variable Structure System (VSS) observer. Besides, a small, low cost, and good response nonlinear controller is designed by using a micro computer that is essential in embedded system for the developments of industrial equipments. Effectiveness of the proposed method is verified by the experimental results

Development of a field test for evaluating aerobic fitness in middle-aged adults: Validity of a 15-m Incremental Shuttle Walk and Run Test

The purpose of this study was to develop a standardized andexternally paced field test (15-m Incremental Shuttle Walk and Run Test [15mISWRT]), incorporating an incremental andprogressive structure, to assess aerobic fitness in middle-aged adults. 68 middle-aged men performed three tests in random order between one to two week intervals: 15-m ISWRT, cardiopulmonary exercise test (CPX), and 1500-m fast walk. Variables evaluated were 15-m ISWRT performance (distance completed), VO2max measured by CPX, 1500-m fast walk performance (walking time), and HR response in 15-m ISWRT and 1500-m fast walk. Validity of the 15-m ISWRT was tested by comparing the associations among the 15-m ISWRT performance, VO2max and the 1500-m fast walk performance. Changes in HR response during the 15-m ISWRT and the 1500-m fast walk were also compared. Correlations between each variable were as follows: the correlation between 15-m ISWRT performance and VO2max was very high, r = 0.86 (p < 0.01), the correlation between the 1500-m fast walk and VO2max was r = −0.51 (p < 0.01). HR response during the 15-m ISWRT gently increased initially, whereas HR response during the 1500-m fast walk rapidly increased from the start. In conclusion, our findings indicate that the 15-m ISWRT is valid and safe for evaluating VO2max in middle-aged adults

Development of a Field Test for Evaluating Aerobic Fitness

The purpose of this study was to investigate the reproducibility and utility of a standardised and externally paced field test (15-m Incremental Shuttle Walk and Run Test [15 mISWRT]) to assess aerobic fitness in middle-aged adults. 14 middle-aged participants performed the 15-m ISWRT 3 times within one week (Test 1, Test 2, Test 3). Reproducibility of the 15-m ISWRT was tested by comparing 15-m ISWRT performance (distance completed), HRmax, and V˙O2max for each test. The utility of the 15-m ISWRT for evaluating V˙O2max over a wide range in middle-aged adults was tested by comparing the range of V˙O2max obtained from the portable expired gas analyzer with the V˙O2max reference values and ranges for health promotion published by Japan\u27s Ministry of Health, Labour and Welfare. A multiple comparison of distance completed in the 15-m ISWRT Test 1, Test 2, and Test 3 found no significant difference between Test 2 and Test 3. The ICC was 0.99 for Test 2 vs. Test 3. V˙O2max measured from the 15-m ISWRT in Test 3 had a minimum value of 22.8 ml/kg/min and a maximum value of 38.7 ml/kg/min. In conclusion, the 15-m ISWRT is reliable and useful for evaluating V˙O2max in middle-aged adults

From feature selection to continuous optimization

Metaheuristic algorithms (MAs) have seen unprecedented growth thanks to their successful applications in fields including engineering and health sciences. In this work, we investigate the use of a deep learning (DL) model as an alternative tool to do so. The proposed method, called MaNet, is motivated by the fact that most of the DL models often need to solve massive nasty optimization problems consisting of millions of parameters. Feature selection is the main adopted concepts in MaNet that helps the algorithm to skip irrelevant or partially relevant evolutionary information and uses those which contribute most to the overall performance. The introduced model is applied on several unimodal and multimodal continuous problems. The experiments indicate that MaNet is able to yield competitive results compared to one of the best hand-designed algorithms for the aforementioned problems, in terms of the solution accuracy and scalability.Comment: Accepted for EA201

Effects of Pulmonary Rehabilitation for Patients with Chronic Pulmonary Diseases with Different Types of Ventilatory Defects: Relationships between Pulmonary Function Parameters and Exercise Torelance

This prospective cohort study was conducted to determine which pulmonary function parameters are useful in the prediction of exercise torelance and exercise-induced hypoxemia (EIH) among patients with chronic pulmonary diseases with different types of ventilatory defects. Fifty one patients with chronic pulmonary diseases who underwent comprehensive pulmonary rehabilitation for periods of 4 to 8 weeks, and who were classified as to different types of ventilatory defects; obstructive, restrictive and mixed type based on their pulmonary functions. All patients were measured for pulmonary function parameters, 6-minute walking distance (6MD) and the activity of daily living (ADL) before and after pulmonary rehabilitation. After pulmonary rehabilitation, the patients demonstrated a significant (p<0.001) increase in 6 MD and ADL scores for all types of ventilatory defects. In the relationship between 6 MD and pulmonary function parameters, the forced expiratory volume in 1 sec. (FEV1.0) was significantly correlated with 6 MD for all types of ventilatory defect. Vital capacity (VC) and maximal voluntary ventilation (MVV) correlated with 6MD in the obstructive and the mixed ventilatory defects, and PaO2 correlated with 6 MD relative to mixed ventilatory defects. In the relationship between EIH and pulmonary function parameters, VC significantly correlated with EIH relative to restrictive ventilatory defects. FEV1.0 and MVV correlated with EIH relative to obstructive ventilatory defects. Our present data suggest that specific pulmonary function parameters which can be correlated with 6 MD and EIH for different types of ventilatory defects, may be useful in terms of devising pulmonary rehabilitation protocols for these patients