scholarly journals Research on the smooth velocity control of a driving switching process of a new pneumatic electric hybrid actuator

2021 ◽  
Vol 12 (2) ◽  
pp. 971-982
Author(s):  
Jiabin Yang ◽  
Xiaoning Li
Keyword(s):  
Velocity Fluctuation ◽  
Low Cost ◽  
Switching Strategy ◽  
Response Characteristics ◽  
Locking Mechanism ◽  
Restart Strategy ◽  
Basic Characteristics ◽  
Application Requirements ◽  
Starting Characteristics ◽  
Hybrid Actuator

Abstract. In order to meet the application requirements of fast-moving, accurate positioning, and low cost, a new type of pneumatic electric hybrid actuator was developed with a positioning accuracy of 0.01 mm. It was found that the velocity fluctuation would occur in the process of driving switching due to the “stop then restart” strategy, resulting in stumbling when positioning. To solve this problem, the basic characteristics of the drive switching mechanism were tested and analyzed. A driving switching strategy called “relay and run” was proposed based on the response characteristics of the locking mechanism in the braking stage and the starting characteristics of the motor. The uniform acceleration was controlled by the motor drive to compensate for the velocity loss so that the overall velocity was slowly reduced. The control model was established, and the experiments were conducted. The results showed that the relay and run switching strategy can eliminate the velocity fluctuation caused by the stop then restart strategy.

scholarly journals Design of Mechanism and Preliminary Field Validation of Low-Cost Transfemoral Rotator for Use in the Developing World

2016 ◽  
Author(s):  
Matthew L. Cavuto ◽  
Matthew Chun ◽  
Nora Kelsall ◽  
Karl Baranov ◽  
Keriann Durgin ◽  
...  
Keyword(s):  
Developing World ◽  
Low Cost ◽  
Field Studies ◽  
Field Validation ◽  
User Testing ◽  
Common Solution ◽  
Locking Mechanism ◽  
Medial Rotation ◽  
Transfemoral Amputees ◽  
And Function

Transfemoral (above-knee) amputees face a unique and challenging set of restrictions to movement and function. Most notably, they are unable to medially rotate their lower-leg and subsequently cross their legs. The best and most common solution to this issue today is a transfemoral rotator, which allows medial rotation of the leg distal to the knee through a lockable turntable mechanism. However, currently available transfemoral rotators can cost thousands of dollars, and few equivalent technologies exist in the developing world. This paper, supported by the results of field studies and user testing, establishes a framework for the design of a low-cost and easily manufacturable transfemoral rotator for use in the developing world. Two prototypes are presented, each with a unique internal locking mechanism and form. A preliminary field study was conducted on six transfemoral amputees in India and qualitative user and prosthetist feedback was collected. Both prototypes successfully allowed all subjects to complete tasks such as crossing legs, putting on pants, and tying shoes while maintaining functionality of walking and standing. Future iterations of the mechanism will be guided by a combination of the most positively received features of the prototypes and general feedback suggestions from the users.

Design and Preliminary Testing of a Novel Dual-Chambered Syringe

2011 ◽  
Vol 5 (2) ◽  
Author(s):  
Karen May-Newman ◽  
Maria T. Matyska ◽  
Martin N. Lee
Keyword(s):  
Low Cost ◽  
Preliminary Test ◽  
Blood Stream ◽  
Medical Procedure ◽  
Dual Chamber ◽  
Two Fluids ◽  
Small Channel ◽  
Locking Mechanism ◽  
Fluid Properties ◽  
Balance Of Forces

Intravenous catheterization is the most common invasive medical procedure today and is designed to introduce medication directly into the blood stream. Common practice is to administer medicine with one syringe, followed by a saline flush to clear the line of any residual medication. The risk of infection due to the introduction of bacteria in the catheter hub is increased with the number of times the hub is accessed. In addition, the two-step process adds millions of nursing hours per year and is prone to error. The goal of this effort was to design and test a dual-chamber syringe that could be reliably used for both dispensing medicine and the saline flush, and be produced at a low cost. The syringe has a novel dual-chamber design with a proximal chamber for medicine and a distal chamber that contains saline. The saline chamber has a fixed volume when the handle is locked into position, which allows the handle to control the variable volume of the medicine chamber. Between the two chambers is a plunger that surrounds the small channel (which is an extension of the distal chamber) that separates the saline from the medicine. When the distal chamber is unlocked, the handle controls the volume of the saline chamber. By this mechanism, the syringe is able inject the medicine followed by the saline flush with a single access to the catheter hub. The smooth operation of the device relies on a locking mechanism to control the rear plunger and volume of the distal saline chamber, and a bubble plug residing in the small channel between the chambers that prevents mixing of the medicine and saline fluids. The bubble plug is held in place by a balance of forces that depend on geometric variables and fluid properties. The chosen design prevents mixing of the two fluids during the operation of the device, which was experimentally validated with mass spectrometry. The dual-chamber syringe has successfully achieved the design goal of a single syringe for the two-step catheter procedure of dispensing medicine and a saline flush. This novel design will reduce the potential for catheter-based infection, medical errors, medical waste, and clinician time. Preliminary test results indicate that this innovation can significantly improve the safety and efficiency of catheter-based administration of medicine.

scholarly journals Multi-Target Detection Method Based on Variable Carrier Frequency Chirp Sequence

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3386 ◽  
Author(s):  
Wei Wang ◽  
Jinsong Du ◽  
Jie Gao
Keyword(s):  
Intelligent Transportation Systems ◽  
Simple Structure ◽  
Low Cost ◽  
Doppler Frequency ◽  
Transportation Systems ◽  
Practical Application ◽  
Frequency Aliasing ◽  
Application Requirements ◽  
Relationship Of ◽  
Cw Radar

Continuous waveform (CW) radar is widely used in intelligent transportation systems, vehicle assisted driving, and other fields because of its simple structure, low cost and high integration. There are several waveforms which have been developed in the last years. The chirp sequence waveform has the ability to extract the range and velocity parameters of multiple targets. However, conventional chirp sequence waveforms suffer from the Doppler ambiguity problem. This paper proposes a new waveform that follows the practical application requirements, high precision requirements, and low system complexity requirements. The new waveform consists of two chirp sequences, which are intertwined to each other. Each chirp signal has the same frequency modulation, the same bandwidth and the same chirp duration. The carrier frequencies are different and there is a frequency shift which is large enough to ensure that the Doppler frequencies for the same moving target are different. According to the sign and numerical relationship of the Doppler frequencies (possibly frequency aliasing), the Doppler frequency ambiguity problem is solved in eight cases. Theoretical analysis and simulation results verify that the new radar waveform is capable of measuring range and radial velocity simultaneously and unambiguously, with high accuracy and resolution even in multi-target situations.

Numerical Simulation for the Starting Characteristics of a Wind Turbine

2020 ◽  
Vol 38 ◽  
pp. 215-221
Author(s):  
Anna Kuwana ◽  
Xue Yan Bai ◽  
Dan Yao ◽  
Haruo Kobayashi
Keyword(s):  
Numerical Simulation ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Farms ◽  
Vertical Axis ◽  
Offshore Wind ◽  
Optimum Shape ◽  
Blade Thickness ◽  
Basic Characteristics ◽  
Starting Characteristics

There are many types of wind turbine. Large propeller-type wind turbines are used mainly for large wind farms and offshore wind power generation. Small vertical-axis wind turbines (VAWTs) are often used in distributed energy systems. In previous studies on wind turbines, the basic characteristics such as torque coefficient have often been obtained during rotation, with the turbine rotating at a constant speed. Such studies are necessary for the proper design of wind turbines. However, it is also necessary to conduct research under conditions in which the wind direction and wind speed change over time. Numerical simulation of the starting characteristics is carried out in this study. Based on the flow field around the wind turbine, the force required to rotate the turbine is calculated. The force used to stop the turbine is modeled based on friction in relation to the bearing. Equations for the motion of the turbine are solved by their use as external force. Wind turbine operation from the stationary state to the start of rotation is simulated. Five parameters, namely, blade length, wind turbine radius, overlap, gap, and blade thickness, are changed and the optimum shape is obtained. The simulation results tend to qualitatively agree with the experimental results for steadily rotating wind turbines in terms of two aspects: (1) the optimal shape has an 20% overlap of the turbine radius, and (2) the larger the gap, the lower the efficiency.

scholarly journals Electrooculograms for Human–Computer Interaction: A Review

Sensors ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 2690 ◽  
Author(s):  
Won-Du Chang
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Eye Movements ◽  
Human Computer Interaction ◽  
Low Cost ◽  
Communication Tools ◽  
Virtual Keyboard ◽  
Basic Characteristics ◽  
Electric Signals ◽  
Lateral Sclerosis ◽  
Computer Interaction

Eye movements generate electric signals, which a user can employ to control his/her environment and communicate with others. This paper presents a review of previous studies on such electric signals, that is, electrooculograms (EOGs), from the perspective of human–computer interaction (HCI). EOGs represent one of the easiest means to estimate eye movements by using a low-cost device, and have been often considered and utilized for HCI applications, such as to facilitate typing on a virtual keyboard, moving a mouse, or controlling a wheelchair. The objective of this study is to summarize the experimental procedures of previous studies and provide a guide for researchers interested in this field. In this work the basic characteristics of EOGs, associated measurements, and signal processing and pattern recognition algorithms are briefly reviewed, and various applications reported in the existing literature are listed. It is expected that EOGs will be a useful source of communication in virtual reality environments, and can act as a valuable communication tools for people with amyotrophic lateral sclerosis.

scholarly journals Numerical Thermal Analysis and 2-D CFD Evaluation Model for An Ideal Cryogenic Regenerator

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 361 ◽  
Author(s):  
Natheer Almtireen ◽  
Jürgen J. Brandner ◽  
Jan G. Korvink
Keyword(s):  
High Reliability ◽  
Low Cost ◽  
Evaluation Model ◽  
Volumetric Flow Rate ◽  
Cooling Capacity ◽  
Heating And Cooling ◽  
The Matrix ◽  
Overall Performance ◽  
Application Requirements ◽  
Vital Element

Regenerative cryocoolers such as Stirling, Gifford–McMahon, and pulse tube cryocoolers possess great merits such as small size, low cost, high reliability, and good cooling capacity. These merits led them to meet many IR and superconducting based application requirements. The regenerator is a vital element in these closed-cycle cryocoolers, but the overall performance depends strongly on the effectiveness of the regenerator. This paper presents a one-dimensional numerical analysis for the idealized thermal equations of the matrix and the working gas inside the regenerator. The algorithm predicts the temperature profiles for the gas during the heating and cooling periods, along with the matrix nodal temperatures. It examines the effect of the regenerator’s length and diameter, the matrix’s geometric parameters, the number of heat transfer units, and the volumetric flow rate, on the performance of an ideal regenerator. This paper proposes a 2D axisymmetric CFD model to evaluate the ideal regenerator model and to validate its findings.

A Theoretic Study on Cam-Clamping Device

2011 ◽  
Vol 295-297 ◽  
pp. 1536-1539 ◽  
Author(s):  
Yuan Chao Deng
Keyword(s):  
Simple Structure ◽  
Theoretical Study ◽  
Low Cost ◽  
The Self ◽  
Clamping Force ◽  
Locking Mechanism ◽  
Different Types ◽  
Cam Profile ◽  
Clamping Device ◽  
Selection Of

A theoretical study has been made on the cam-clamping device. In this article, we consider specifically the calculations of cam geometry, calculations of clamping force and clamping torque, conditions for self-locking, and conditions for contact strength. Machine fixtures are essential in the process of mechanical manufacturing. There are many different types of fixtures, such as manual jig, pneumatic clamps, hydraulic fixtures, electric fixtures, etc. There are also many ways of clamping, such as incline clamp, screw clamp, eccentric circle clamp, hinge clamp [1], among which the eccentric circle clamp finds wide applications, especially in fast-clamping devices. Although the circular eccentric fixture possesses the advantages of simple structure, convenient manufacturing, and low cost, it suffers the drawbacks of small clamping force, short clamping-surface travel distance, and unreliable self-locking mechanism. The cam-clamping device discussesed in this article involves replaceing the eccentric circle with a cam, as shown in Fig. 1. The cam profile curve can be designed according to any requirements. The advantages of this replacement are obvious, in addition to preserving the advantages of the circular eccentric fixture, the cam-clamping can be designed according to the actual needs of clamping paths and selection of the appropriate cam profile to improve the self-locking.

scholarly journals Activity-based costing as an information basis for an efficient strategic management process

2013 ◽  
Vol 58 (197) ◽  
pp. 95-119
Author(s):  
Djordje Kalicanin ◽  
Vladan Knezevic
Keyword(s):  
Balanced Scorecard ◽  
Low Cost ◽  
Activity Based Costing ◽  
Strategic Decisions ◽  
Cost Information ◽  
Monitoring Cost ◽  
Cost Behaviour ◽  
Basic Characteristics ◽  
A Company ◽  
Information Basis

Activity-based costing (ABC) provides an information basis for monitoring and controlling one of two possible sources of competitive advantage, low-cost production and lowcost distribution. On the basis of cost information about particular processes and activities, management may determine their contribution to the success of a company, and may decide to transfer certain processes and activities to another company. Accuracy of cost information is conditioned by finding an adequate relation between overhead costs and cost objects, identifying and tracing cost drivers and output measures of activities, and by monitoring cost behaviour of different levels of a product. Basic characteristics of the ABC approach, such as more accurate cost price accounting of objects, focusing on process and activity output (rather than only on resource consumption) and on understanding and interpretation of cost structure (rather than on cost measurement), enable managers to estimate and control future costs more reliably. Thus the ABC methodology provides a foundation for cost tracing, analysis, and management, which entails making quality and accurate operative and strategic decisions as a basis for the longterm orientation of a company. ABC is also complementary to the widely accepted technique of strategic planning and strategy implementation known as Balanced Scorecard (BSC).

scholarly journals Review on Pressure Sensors: A Perspective from Mechanical to Micro-electro-mechanical systems

2021 ◽  
Author(s):  
Ankur Gupta
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Pressure Sensors ◽  
Micro Electro Mechanical System ◽  
Single Chip ◽  
Micro Electro Mechanical Systems ◽  
Compact Size ◽  
Wide Range ◽  
Fabrication Procedure ◽  
Application Requirements

Swiftly emerging research prospects in the Micro-Electro-Mechanical System (MEMS) enable to build of complex and sophisticated microstructures on a substrate containing moving masses, cantilevers, flexures, levers, linkages, dampers, gears, detectors, actuators, and many more on a single chip. One of the MEMS initial products that emerged into the micro-system technology is the MEMS pressure sensor. Because of their high performance, low cost, and compact size, these sensors are extensively being adopted in numerous applications viz., aerospace, automobile, and bio-medical domain, etc. These application requirements drive and impose tremendous conditions on sensor design to overcome the tedious design and fabrication procedure before its reality. MEMS-based pressure sensors enable a wide range of pressure measurements as per the application requirements. Considering its vast utility in industries, this paper presents a detailed review of MEMS-based pressure sensors and their wide area of applications, their design aspects, and challenges, to provide state of an art gist to the researchers of a similar domain in one place.

scholarly journals Microencapsulation of Tangeretin in a Citrus Pectin Mixture Matrix

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1200
Author(s):  
Xiuxiu Sun ◽  
Randall G. Cameron ◽  
John A. Manthey ◽  
Wayne B. Hunter ◽  
Jinhe Bai
Keyword(s):  
Sodium Alginate ◽  
Spray Drying ◽  
Low Cost ◽  
Citrus Pectin ◽  
Retention Efficiency ◽  
Technical Requirements ◽  
Pharmaceutical Industries ◽  
Basic Characteristics ◽  
Bergamot Oil ◽  
Alginate Matrix

The objectives of this research were to microencapsulate tangeretin, and to evaluate the basic characteristics of the microcapsule products. Tangeretin is a polymethoxyflavone (PMF) which has been revealed to possess various health benefits and is abundant in tangerine and other citrus peels. Microencapsulation technology is widely employed in the food and pharmaceutical industries to exploit functional ingredients, cells, and enzymes. Spray drying is a frequently applied microencapsulation method because of its low cost and technical requirements. In this research, tangeretin dissolved at different concentrations in bergamot oil was microencapsulated in a citrus pectin/sodium alginate matrix. The resulting microcapsule powder showed promising physical and structural properties. The retention efficiency of tangeretin was greater at a concentration of 2.0% (98.92%) than at 0.2% (71.05%), probably due to the higher temperature of the emulsion during the homogenizing and spray-drying processes. Encapsulation efficiency was reduced with increased concentration of tangeretin. Our results indicate that tangeretin could be successfully encapsulated within a citrus pectin/sodium alginate matrix using bergamot oil as a carrier.

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