Small Motor Research Articles

A novel hydraulic transmission solution to large offshore wind turbine: Design and control strategy

As a comparative solution to gearbox transmission, the hydrostatic transmission has potential to improve offshore wind turbine reliability. However, drivetrain efficiency of hydrostatic transmission is relatively low at low wind speed. To solve this problem, a digital hydrostatic transmission solution for large offshore wind turbine is proposed. The large variable displacement motor in hydrostatic transmission is replaced by multiple fixed displacement motors and a small variable displacement motor. However the wind is turbulent in nature. This results in frequent switching of fixed displacement hydraulic motors. Therefore in this study a control strategy of large utility digital hydrostatic wind turbine under turbulent wind is proposed. The torque control of digital hydrostatic wind turbine is presented. The digital displacement switching scheme is developed. The system pressure controls during motor switching are studied. The dynamic performances and annual energy production of digital hydrostatic wind turbine under turbulent wind are studied. Results show the effectiveness of the proposed control strategy for digital hydrostatic wind turbine. The mean turbine output power at different mean wind speeds of hydrostatic and digital hydrostatic wind turbines are studied and compared. Results show the digital hydrostatic wind turbine has a 1.6% annual energy production improvement than the hydrostatic wind turbine.

Comparison of the Design of 3-Pole BLDC Actuators/Motors with a Rotor Based on a Single Permanent Magnet.

Permanent Magnet (PM) Brushless Direct Current (BLDC) actuators/motors have many advantages over conventional machines, including high efficiency, easy controllability over a wide range of operating speeds, etc. There are many prototypes for such motors; some of them have a very complicated construction, and this ensures their high efficiency. However, in the case of household appliances, the most important thing is simplicity, and, thus, the lowest price of the design and production. This article presents a comparison of computer models of different design solutions for a small PM BLDC motor that uses a rotor in the form of a single ferrite magnet. The analyses were performed by using the finite element method. This paper presents unique self-defined parts of basic PM BLDC actuators. With their help, various design solutions were compared with the PM BLDC motor used in household appliances. The authors proved that the reference device is the lightest one and has a lower cogging torque compared to other actuators, but also has a slightly lower driving torque.

A Comparative Research of Thrust Simulation and Practice for the Small Solid Rocket Motor

In practice, it is found that the simulation method applicable to the conventional size rocket motor cannot be directly applied to the design of the small rocket motor. Due to the change of size, the simulated thrust results differ greatly from the actual thrust results. In this paper, the tube grain and star grain are taken as examples to compare the simulated results with the actual experimental results. First, we determine a group of independent variables that can well reflect the changes of the main variables as a pretreatment and then use the zero dimensional interior ballistic algorithm for simulation. Finally, we design and conduct control experiments to draw a conclusion. The theoretical thrust was obtained by simulation and calculation, and the actual thrust was obtained by a lot of experiments. It was found that there were large offsets between the two types of grains, and the specific offsets corresponding to the two types of grains were obtained. The results show that there is a great difference between the simulated result and the actual result, which has a certain guiding significance for the design and research of small solid rocket motor.

Spiderweb Cellular Structures Manufactured via Additive Layer Manufacturing for Aerospace Application

With increasing the energy costs and aiming for fossil-free Europe, cellular structures could provide a cost-effective tool for saving fuel consumption in aircraft. To achieve this goal, a cellular structure topology is a rapidly growing area of research facilitated by developments in additive layer manufacturing. These low-density structures are particularly promising for their aerospace applications. In this paper, four cellular structure topologies are developed to serve as a vibration damper in small electric aircraft motor, we have compared their performance with the original motor holder in the aircraft. This paper introduces the roadmap of scaffolding concept design and provides a novel concept in vibration damping. Based on the FEA simulation, aluminium 6061T spiderweb-inspired lattices (weight 0.3473 g and porosity 84%) have proven to have the lowest natural resonance and highest yield strength to weight ratio compared to other scaffolding concepts.

Role of the duodenal microbiota in functional dyspepsia.

Functional dyspepsia (FD) is a common and debilitating gastrointestinal disorder attributed to altered gut-brain interactions. While the etiology of FD remains unknown, emerging research suggests the mechanisms are likely multifactorial and heterogenous among patient subgroups. Small bowel motor disturbances, visceral hypersensitivity, chronic microinflammation, and increased intestinal tract permeability have all been linked to the pathogenesis of FD. Recently, alterations to the gut microbiome have also been implicated to play an important role in the disease. Changes to the duodenal microbiota may either trigger or be a consequence of immune and neuronal disturbances observed in the disease, but the mechanisms of influence of small intestinal flora on gastrointestinal function and symptomatology are unknown. This review summarizes and synthesizes the literature on the link between the microbiota, low-grade inflammatory changes in the duodenum and FD. This review is not intended to provide a complete overview of FD or the small intestinal microbiota, but instead outline some of the key conceptual advances in understanding the interactions between altered gastrointestinal bacterial communities; dietary factors; host immune activation; and stimulation of the gut-brain axes in patients with FD versus controls. Current and emerging treatment approaches such as dietary interventions and antibiotic or probiotic use that have demonstrated symptom benefits for patients are reviewed, and their role in modulating the host-microbiota is discussed. Finally, suggested opportunities for diagnostic and therapeutic improvements for patients with this condition are presented.

CES 2022: Less is More

AbstractScaled‐down show still delivers top‐notch exhibits and innovation aplenty.

Single‐phase small capacitor motor drive system with high‐efficiency buck active power decoupling converter

This paper proposes a novel active power decoupling circuit (APDC) based on modified Buck converter to reduce the DC-link voltage ripple of small capacitor motor drive systems. The APDC is placed between the Boost PFC circuit and the DC-link, and has two energy flow paths, and the sum of the power decoupling capacitor and the DC-link capacitor voltage equals to the output voltage of the Boost converter. With these configurations, the voltage of the decoupling capacitor can be precisely controlled to be the same as the AC component of the output voltage of the Boost converter, thereby effectively reducing the DC-link voltage ripple. Another unique feature of the proposed APDC is that the inductor works in discontinuous current mode and only work for half of the time, which not only reduces the current stress of power switches, but also further improves the efficiency of the proposed APDC. Then, an instantaneous voltage control method is investigated to reduce the DC-link voltage drop, which significantly improve the dynamic performance of the motor. The design guideline of key components is given in detail. The feasibility of the small capacitor motor drive system based on the proposed APDC is verified by experimental results.

フレキシブルPCB巻線を用いた小型磁気浮上モータの製作誤差が最大トルクに及ぼす影響の検討

フレキシブルPCB巻線を用いた小型磁気浮上モータの製作誤差が最大トルクに及ぼす影響の検討

Evaluation of Vibrotactile Output From a Rotating Motor Actuator.

Specialized vibrotactile actuators are widely used to output haptic sensations due to their portability and robustness; some models are expensive and capable, while others are economical but weaker and less expressive. To increase the accessibility of high-quality haptics, we designed a cost-effective actuation approach called the rotating motor actuator (RMA): it uses a small DC motor to generate vibrotactile cues on a rigid stylus. We conducted a psychophysical experiment where eighteen volunteers matched the RMA's vibration amplitudes with those from a high-quality reference actuator (Haptuator Mark II) at twelve frequencies from 50 Hz to 450 Hz. The average error in matching acceleration magnitudes was 10.2%. More current was required for the RMA than the reference actuator; a stronger DC motor would require less current. Participants also watched a video of a real tool-mediated interaction with playback of recorded vibrotactile cues from each actuator. 94.4% of the participants agreed that the RMA delivered realistic vibrations and audio cues during this replay. 83.3% reported that the RMA vibrations were pleasant, compared to 66.7% for the reference. A possible cause for this significant difference may be that the reference actuator (which has a mechanical resonance) distorts low-frequency vibrations more than the RMA does.

A review on smart attendance system with protection

Attendance is an important task in any institution. Manual methods generally waste a lot of time. They are also not the safest and fastest option. In schools and colleges, the most common technique for attendance is calling the students' names, and in industries, the most common method is signing a register which generally needs extra time to do the attendance. A "Smart Attendance System with Protection" is proposed to solve these problems. This project is mainly divided into 3 parts according to its applications which includes, attendance, thermal screening and ultrasonic sensors. For the automatic attendance part, the Local Binary Pattern Histogram (LBPH) method is used for the face recognition of the person. LBPH is considered the most useful technique for face recognition. For the second part of the project, thermal screening, a sensor (MLX90614) is used to take the temperature of the person and check if it is normal or not. In the third part of the project, ultrasonic sensors are used to detect the hands of the person. Under the sanitization section, and after detection, a small pump motor is used to pour the sanitizer into the hands of the person for the sanitization of their hands. Manual records can be easily extracted from the Smart Attendance System when needed. Attendance record manipulation is not possible in the system. The proposed device uses the Raspberry Pi, IRT, Ultrasonic Sensor, Pi Camera, and Pump Motor. An attendance record is generated and stored in excel format.

Research on a New Adaptive Integral Sliding Mode Controller Based on a Small BLDC

A new adaptive saturation Integral Sliding Mode Controller (ADSA-ISMC) is presented to solve the speed fluctuation problem caused by a small brushless DC motor (S-BLDC) under variable load. First, according to the characteristics of S-BLDC and Kalman filter, a Kalman-based S-BLDC load disturbance observer is established, and an adaptive integrated sliding mode controller (AD-ISMC) is constructed based on the motor load obtained by the observer. Then, we introduce the saturation function into the input error link of the traditional integral sliding mode function, to propose a new ADSA-ISMC to improve the windup phenomenon produced by the integral sliding mode controller and prove the stability and convergence of the controller by the Lyapunov method. Finally, the experimental results show that the Kalman load disturbance observer can observe the motor load disturbance well. In addition, when a load of S-BLDC changes, many speed control performance indexes of ADSA-ISMC are significantly better than SMC and AD-ISMC. Theoretical analysis and experimental results show that the ADSA-ISMC proposed in this paper shows excellent control performance in S-BLDC speed control.

Economic Challenges Compromising Resilience to the War against COVID-19 among Border Communities in Busia County, Kenya

By March 2020, the pandemic had spread to both developed and third world countries. These countries reported multiple cases of the virus within their borders, and deaths related to the virus. This study sought to establish the economic challenges that compromise the war against COVID-19 among border communities in Busia County. The study was conducted in the two major border points comprising Busia and Malaba towns. In Busia town, the study was carried out in the entire Matayos and Nambale sub counties, while in Malaba town the study was conducted in Teso South and Teso North Sub Counties. The respondents included motor bike riders and small scale traders in the identified Sub Counties. Stratified and simple random sampling methods were used to select a representative sample of the population with the aid of lists of registered members of the motor bike riders and small scale traders. The study adopted a descriptive survey research design. Questionnaires and interview guide were used to collect data from the respondents. In the analysis done, the respondents to the questionnaires included the small scale traders and motor bike riders. It was established that the poverty levels had risen even higher than usual and a number of them could not make ends meet. Daily income for small scale traders had reduced drastically and some had closed part of their business due to lack of customers. This is because of government stringent measures, such as: curfews ban on cross-border trade and social distancing which affected business activities. The small scale traders did not receive any support from the government or well-wishers to revamp their business.

Field study of remote controlled Agrobot

Agriculture sector is the backbone of Indian economy and hence it is important to modernize the different agriculture practices for improving the crop health and also for better yielding of the crop and at the same time ensure safety of the Indian farmers. One important area identified is that of the technique of pesticide spraying. Traditionally, Indian farmers use backpack sprayers that are actuated either by the lever or small motor pump that requires continuous muscle movement by the farmer which may lead to muscular disfunctions and further may result in entry of these pesticides into formers body either through inhalation or by absorption by the skin. Therefore, a new remote controlled agriculture robot named AGROBOT is explained in detail in the current work. The Agrobot is a remotely piloted electric vehicle that can be used for pesticide, insecticide etc. thereby the current innovation robot fulfil the task of providing safety to the farmers as it is remotely piloted.

Development and disordres in the process of communication of people with the chromosome 13q deletion syndrome

Chromosome 13q deletion syndrome is a kind of chromosome aberration which belongs to rarely occurring genetic abnormalities. Chromosome 13q deletion results in phenotypic disorders such as malfunctions in the central nervous system, anatomical changes of the body, as well as disorders in large and small motor skills. One of the possible consequences of the problems in motor skills development are speech development disorders, particularly concerning speech production. Other problems may relate to breathing, phonation and articulation. Additionally, on the one hand, some persistent reflexes in the orofacial area can be observed, while, on the other hand, some reflexes are absent. In the case of chromosome 13q deletion, the logopedic therapy contains also swallowing, as well as exercises which aim at improving the muscle tension in the area of face, articulators, neck, shoulders, chest and upper limbs. Disorders in speech production may take form of dysarthria, for example. Whereas, learning to communicate may require to introduce alternative communication – non-verbal communication within language production.

Spatial-temporal motion control via composite cam-follower mechanisms

Motion control, both on the trajectory and timing, is crucial for mechanical automata to perform functionalities such as walking and entertaining. We present composite cam-follower mechanisms that can control their spatial-temporal motions to exactly follow trajectories and timings specified by users, and propose a computational technique to model, design, and optimize these mechanisms. The building blocks of our mechanisms are a new kind of cam-follower mechanism with a modified joint, in which the follower can perform spatial motion on a planar, cylindrical, or spherical surface controlled by the 3D cam's profile. We parameterize the geometry of these cam-follower mechanisms, formulate analytical equations to model their kinematics and dynamics, and present a method to combine multiple cam-follower mechanisms into a working mechanism. Taking this modeling as a foundation, we propose a computational approach to designing and optimizing the geometry and layout of composite cam-follower mechanisms, with an objective of performing target spatial-temporal motions driving by a small motor torque. We demonstrate the effectiveness of our technique by designing different kinds of personalized automata and showing results not attainable by conventional mechanisms.

Design and motion analysis of a small motor stator multi-wire paralleled winding hybrid robot

Abstract. The working space of small motor stators is narrow, and most of them are manual winding. It is difficult to guarantee the uniform arrangement of enameled wires by multi-wire winding. To solve these problems, a three-phase parallel equivalent multi-wire winding robot is proposed to achieve large output torque of the motor. Firstly, according to the equivalent model, the structure of the large arm, small arm and manipulator is designed to determine the motion model of the winding robot. Euler's kinematics theory is used to analyze the change of the working position of the arm, and the rotation matrix of the arm and the constraint equation of the motion vector of each branch chain are established. The motion model of the arm and the manipulator are established using inverse kinematics and analytical analysis. The motion pose of each joint of the winding robot is studied to ensure that the robot realizes a three-phase parallel multi-wire winding motion. ADAMS software was used for kinematic simulation analysis of the winding robot. The displacement of the branch chain on the xyz axis was represented by the torque of the virtual motor to verify the correctness of the inverse kinematics solution and the closure condition of the manipulator block. Finally, the ROS simulation platform is built to simulate the joint motion planning of the winding robot to verify the multi-line parallel principle and the feasibility of the multi-line parallel winding hybrid robot. The research results of this paper provide a theoretical reference for multi-wire parallel winding equipment control.

Active Electronic Egg for Breeding of Endangered Birds

This work presents a prototype of an artificial egg for use in breeding centres for endangered birds. These eggs replace the inert artificial eggs that are given to the birds while the natural egg is incubated in the laboratory. When the chick hatches, it is given to the parents to continue breeding. This first prototype of the active egg is designed for the bearded vulture (Gypaetus barbatus), simulating the sounds and movements of the chick inside, and with the same appearance, size and weight as a natural one. The movements and sounds of the active artificial egg are made at the request of its caregiver and under his supervision and control in real time via a wireless connection. The active artificial egg has battery-powered circuitry inside that allows it to maintain wireless communication between the caregiver and the egg, because the egg must not perform autonomous physical actions at any time. This prototype has been tested for three seasons on a foster male and a natural couple of birds with good results because the birds have not rejected the prototype and have shown exactly the same behaviour exhibited when incubating a natural egg. The electronic system has among other circuits a microcontroller, a small motor to produce vibrations that simulate the movement of the chick and an mp3 player for the reproduction of sounds previously recorded on a microSD card. A low power consumption system has been designed to increase the autonomy of the device.

Portable stirring device for the on-site extraction of environmental waters using magnetic hydrophilic-lipophilic balance tape

The spatial heterogeneity of environmental systems makes sampling at multiple locations crucial to provide complete and representative information. The on-site application of an extraction technique simplifies the sampling logistics, increasing sample integrity during transportation and storage. This article presents a portable, simple, and low-cost device capable of performing the simultaneous on-site extraction of several environmental water samples. The device consists of a small electric motor integrated into the plastic cap of a conventional glass bottle and operated with a portable battery. The electric motor provides stirring to a novel magnetic sorptive phase based on the deposition of hydrophilic-lipophilic balance (HLB) particles over a magnetic tape. The use of open technology makes the device globally affordable. In this first approach, the isolation and preconcentration of atrazine and simazine have been selected as proof of concept. Using an internal standard made unnecessary the adjustment of the ionic strength before the extraction, thus simplifying the analytical procedure. Under the optimum conditions and using direct infusion mass spectrometry as the instrumental technique, detection limits as low as 15 ng/L were obtained. The precision calculated at three different levels was better than 8.3%. The accuracy, calculated with spiked samples, indicates the applicability of the approach for environmental water analysis.

Electromagnetic design and thermal analysis of module combined permanent magnet motor with wrapped type for mine ball mill

With the large-scale development of the ball mill, the direct-drive gearless ball mill has emerged, eliminating the limitation of the transmission torque of large gear. However, it is difficult to process, transport, install and maintain the gearless ball mill because of its vast volume, and the coils cannot be decoupled freely. Therefore, this work proposes a module combined permanent magnet motor with wrapped type for mine ball mill (MBMWT-MCPMM). Based on the principle of removing coils, the stator is modularized. Each module can be regarded as a small rotary motor, which improves the reliability and fault tolerance of the motor. In this work, the structure and general design process of the MBMWT-MCPMM are described, and the electromagnetic performance is simulated and analysed. The influence of different factors on the cooling effect of the motor and the temperature rise of different modules during fault-tolerant operation are analysed. An 80 kW prototype is developed, and its experiments are carried out. The experimental results verify the validity of the related design and analysis.

A Gimballed Control Moment Gyroscope Cluster Design for Spacecraft Attitude Control

This paper addresses the problem of singularity avoidance in a cluster of four Single-Gimbal Control Moment Gyroscopes (SGCMGs) in a pyramid configuration when used for the attitude control of a satellite by introducing a new gimballed control moment gyroscope (GCMG) cluster scheme. Four SGCMGs were used in a pyramid configuration, along with an additional small and simple stepper motor that was used to gimbal the full cluster around its vertical (z) axis. Contrary to the use of four variable-speed control moment gyroscopes (VSCMGs), where eight degrees of freedom are available for singularity avoidance, the proposed GCMG design uses only five degrees of freedom (DoFs), and a modified steering law was designed for the new setup. The proposed design offers the advantages of SGCMGs, such as a low weight, size, and reduced complexity, with the additional benefit of overcoming the internal elliptic singularities, which create a minor attitude error. A comparison with the four-VSCMG cluster was conducted through numerical simulations, and the results indicated that the GCMG design was considerably more efficient in terms of power while achieving a better gimbal configuration at the end of the simulation, which is essential when it is desired for different manoeuvres to be consecutively executed. Additionally, for a nano-satellite of a few kilograms, the results prove that it is feasible to manufacture the GCMG concept by using affordable and lightweight commercial off-the-shelf (COTS) stepper motors.