scholarly journals Design of a Plantar Pressure Insole Measuring System Based on Modular Photoelectric Pressure Sensor Unit

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3780
Author(s):  
Bin Ren ◽  
Jianwei Liu
Keyword(s):  
Plantar Pressure ◽  
Cooperative Control ◽  
Low Cost ◽  
Fast Response ◽  
Photoelectric Effect ◽  
Measuring System ◽  
Human Walking ◽  
Human Gait ◽  
Pressure Sensing ◽  
Sensor Unit

Accurately perceiving and predicting the parameters related to human walking is very important for man–machine coupled cooperative control systems such as exoskeletons and power prostheses. Plantar pressure data is rich in human gait and posture information and is an essential source of reference information as the input of the exoskeleton control system. Therefore, the proper design of the pressure sensing insole and validation is a big challenge considering the requirements such as convenience, reliability, no interference and so on. In this research, we developed a low-cost modular sensing unit based on the principle of photoelectric sensing and designed a plantar pressure sensing insole to achieve the purpose of sensing human walking gait and posture information. On the one hand, the sensor unit is made of economy-friendly commercial flexible circuits and elastic silicone, and the mechanical and electrical characteristics of the modular sensor unit are evaluated by a self-developed pressure-related calibration system. The calibration results show that the modular sensor based on the photoelectric sensing principle has fast response and negligible hysteresis. On the other hand, we analyzed the area where the plantar pressure is densely distributed. One benefit of the modular sensing unit design is that it is rather convenient to fabricate different insole solutions, so we fabricated and compared several pressure-sensitive insole solutions in this preliminary study. During the dynamic locomotion experiments of wearing the pressure-sensing insole, the time series signal of each sensor unit was collected and analyzed. The results show that the pressure sensing insole based on the photoelectric effect can sense the distribution of the plantar pressure by capturing the deformation of the insole caused by the foot contact during locomotion, and provide reliable gait information for wearable applications.

scholarly journals The grades and freshness assessment of eggs based on density detection using machine vision and weighing sensor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Supakorn Harnsoongnoen ◽  
Nuananong Jaroensuk
Keyword(s):  
Machine Vision ◽  
Vision System ◽  
Low Cost ◽  
Measuring System ◽  
Coefficient Of Determination ◽  
Water Displacement ◽  
Non Invasive ◽  
Future Potential ◽  
Non Destructive ◽  
Egg Freshness

AbstractThe water displacement and flotation are two of the most accurate and rapid methods for grading and assessing freshness of agricultural products based on density determination. However, these techniques are still not suitable for use in agricultural inspections of products such as eggs that absorb water which can be considered intrusive or destructive and can affect the result of measurements. Here we present a novel proposal for a method of non-destructive, non-invasive, low cost, simple and real—time monitoring of the grading and freshness assessment of eggs based on density detection using machine vision and a weighing sensor. This is the first proposal that divides egg freshness into intervals through density measurements. The machine vision system was developed for the measurement of external physical characteristics (length and breadth) of eggs for evaluating their volume. The weighing system was developed for the measurement of the weight of the egg. Egg weight and volume were used to calculate density for grading and egg freshness assessment. The proposed system could measure the weight, volume and density with an accuracy of 99.88%, 98.26% and 99.02%, respectively. The results showed that the weight and freshness of eggs stored at room temperature decreased with storage time. The relationship between density and percentage of freshness was linear for the all sizes of eggs, the coefficient of determination (R2) of 0.9982, 0.9999, 0.9996, 0.9996 and 0.9994 for classified egg size classified 0, 1, 2, 3 and 4, respectively. This study shows that egg freshness can be determined through density without using water to test for water displacement or egg flotation which has future potential as a measuring system important for the poultry industry.

scholarly journals Deep Convolutional and LSTM Networks on Multi-Channel Time Series Data for Gait Phase Recognition

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 789
Author(s):  
David Kreuzer ◽  
Michael Munz
Keyword(s):  
Gait Analysis ◽  
Time Series Data ◽  
Low Cost ◽  
Analysis Data ◽  
Gait Disorders ◽  
Human Gait ◽  
Series Data ◽  
Ageing Society ◽  
Time Motion ◽  
Gait Phase

With an ageing society comes the increased prevalence of gait disorders. The restriction of mobility leads to a considerable reduction in the quality of life, because associated falls increase morbidity and mortality. Consideration of gait analysis data often alters surgical recommendations. For that reason, the early and systematic diagnostic treatment of gait disorders can spare a lot of suffering. As modern gait analysis systems are, in most cases, still very costly, many patients are not privileged enough to have access to comparable therapies. Low-cost systems such as inertial measurement units (IMUs) still pose major challenges, but offer possibilities for automatic real-time motion analysis. In this paper, we present a new approach to reliably detect human gait phases, using IMUs and machine learning methods. This approach should form the foundation of a new medical device to be used for gait analysis. A model is presented combining deep 2D-convolutional and LSTM networks to perform a classification task; it predicts the current gait phase with an accuracy of over 92% on an unseen subject, differentiating between five different phases. In the course of the paper, different approaches to optimize the performance of the model are presented and evaluated.

scholarly journals Clustering-Based Component Fraction Estimation in Solid–Liquid Two-Phase Flow in Dredging Engineering

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5697
Author(s):  
Chang Sun ◽  
Shihong Yue ◽  
Qi Li ◽  
Huaxiang Wang
Keyword(s):  
Clustering Algorithm ◽  
Two Phase Flow ◽  
Low Cost ◽  
Fast Response ◽  
New Method ◽  
Phase Flow ◽  
Reference Distribution ◽  
Two Phase ◽  
Long Time ◽  
Solid Liquid

Component fraction (CF) is one of the most important parameters in multiple-phase flow. Due to the complexity of the solid–liquid two-phase flow, the CF estimation remains unsolved both in scientific research and industrial application for a long time. Electrical resistance tomography (ERT) is an advanced type of conductivity detection technique due to its low-cost, fast-response, non-invasive, and non-radiation characteristics. However, when the existing ERT method is used to measure the CF value in solid–liquid two-phase flow in dredging engineering, there are at least three problems: (1) the dependence of reference distribution whose CF value is zero; (2) the size of the detected objects may be too small to be found by ERT; and (3) there is no efficient way to estimate the effect of artifacts in ERT. In this paper, we proposed a method based on the clustering technique, where a fast-fuzzy clustering algorithm is used to partition the ERT image to three clusters that respond to liquid, solid phases, and their mixtures and artifacts, respectively. The clustering algorithm does not need any reference distribution in the CF estimation. In the case of small solid objects or artifacts, the CF value remains effectively computed by prior information. To validate the new method, a group of typical CF estimations in dredging engineering were implemented. Results show that the new method can effectively overcome the limitations of the existing method, and can provide a practical and more accurate way for CF estimation.

Ultrasensitive, flexible, and low-cost nanoporous piezoresistive composites for tactile pressure sensing

Nanoscale ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 2779-2786 ◽  
Author(s):  
Jing Li ◽  
Santiago Orrego ◽  
Junjie Pan ◽  
Peisheng He ◽  
Sung Hoon Kang
Keyword(s):  
Carbon Nanotube ◽  
Polymer Composites ◽  
Low Cost ◽  
Pressure Sensors ◽  
Nanoporous Carbon ◽  
Pressure Sensing ◽  
Etching Method ◽  
Piezoresistive Pressure Sensors

We report a facile sacrificial casting–etching method to synthesize nanoporous carbon nanotube/polymer composites for ultra-sensitive and low-cost piezoresistive pressure sensors.

Experimental Study on New Wave Measurement Using Passive Underwater Acoustics

2008 ◽  
Author(s):  
Jing Li ◽  
Dingyong Yu ◽  
Huaxing Liu
Keyword(s):  
Virtual Instrument ◽  
Low Cost ◽  
Measuring System ◽  
Time Data ◽  
Significant Wave ◽  
Wave Measurement ◽  
Wave Heights ◽  
Mean Wave Period ◽  
Passive Acoustic ◽  
User Friendly

The passive acoustic-based wave measurement via hydrophones is presented in this paper. It has the potential to measure non-intrusively, implement with low cost and with higher resolution. Details of experiments, real-time data recording and processing are described respectively. Particularly, the portable data acquisition system based on virtual instrument technique is designed to make the in situ measurement convenient and user-friendly. Special emphasis is put on FFT filtering technique to band pass the signal fast and efficiently. The key wave parameters, i.e. the mean wave period and the significant wave height, can be obtained from the comparatively safe and stable underwater by means of submerged hydrophones. Considering the pressure sensor has been widely used in the ocean wave measurement, it is deployed simultaneously to test the feasibility of the new system. The result shows that the present measuring system can give satisfactory measurement of significant wave heights and average wave periods in shallow water despite of the little deviation.

scholarly journals Advances in the Structural Health Monitoring of Bridges Using Piezoelectric Transducers

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4312 ◽  
Author(s):  
Yunzhu Chen ◽  
Xingwei Xue
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Piezoelectric Materials ◽  
Low Cost ◽  
Rapid Development ◽  
Concrete Strength ◽  
Steel Corrosion ◽  
Fast Response ◽  
Future Application ◽  
Structural Health

With the rapid development of the world’s transportation infrastructure, many long-span bridges were constructed in recent years, especially in China. However, these bridges are easily subjected to various damages due to dynamic loads (such as wind-, earthquake-, and vehicle-induced vibration) or environmental factors (such as corrosion). Therefore, structural health monitoring (SHM) is vital to guarantee the safety of bridges in their service lives. With its wide frequency response range, fast response, simple preparation process, ease of processing, low cost, and other advantages, the piezoelectric transducer is commonly employed for the SHM of bridges. This paper summarizes the application of piezoelectric materials for the SHM of bridges, including the monitoring of the concrete strength, bolt looseness, steel corrosion, and grouting density. For each problem, the application of piezoelectric materials in different research methods is described. The related data processing methods for four types of bridge detection are briefly summarized, and the principles of each method in practical application are listed. Finally, issues to be studied when using piezoelectric materials for monitoring are discussed, and future application prospects and development directions are presented.

scholarly journals Low-Cost and Energy-Saving Wireless Sensor Network for Real-Time Urban Mobility Monitoring System

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Joyoung Lee ◽  
Zijia Zhong ◽  
Bo Du ◽  
Slobodan Gutesa ◽  
Kitae Kim
Keyword(s):  
Energy Saving ◽  
Fiber Optics ◽  
Monitoring System ◽  
Data Center ◽  
Low Cost ◽  
Wireless Sensor ◽  
Navigation Systems ◽  
Urban Mobility ◽  
Proof Of Concept ◽  
Sensor Unit

This paper presents a low-cost and energy-saving urban mobility monitoring system based on wireless sensor networks (WSNs). The primary components of the proposed sensor unit are a Bluetooth sensor and a Zigbee transceiver. Within the WSN, the Bluetooth sensor captures the MAC addresses of Bluetooth units equipped in mobile devices and car navigation systems. The Zigbee transceiver transmits the collected MAC addresses to a data center without any major communications infrastructures (e.g., fiber optics and 3G/4G network). A total of seven prototype sensor units have been deployed on roadway segments in Newark, New Jersey, for a proof of concept (POC) test. The results of the POC test show that the performance of the proposed sensor unit appears promising, resulting in 2% of data drop rates and an improved Bluetooth capturing rate.

scholarly journals Design of Biomechanical Legs with a Passive Toe Joint for Enhanced Human-like Walking

2017 ◽  
Vol 14 (2) ◽  
pp. 166 ◽  
Author(s):  
Riadh Zaier ◽  
A. Al-Yahmedi
Keyword(s):  
Design Procedure ◽  
Human Walking ◽  
Human Gait ◽  
Design Parameters ◽  
Sultan Qaboos University ◽  
Motion Trajectories ◽  
Normal Human ◽  
Working Principle ◽  
Mass Spring ◽  
Torsion Springs

This paper presents the design procedure of a biomechanical leg, with a passive toe joint, which is capable of mimicking the human walking. This leg has to provide the major features of human gait in the motion trajectories of the hip, knee, ankle, and toe joints. Focus was given to the approach of designing the passive toe joint of the biomechanical leg in its role and effectiveness in performing human like motion. This study was inspired by experimental and theoretical studies in the fields of biomechanics and robotics. Very light materials were mainly used in the design process. Aluminum and carbon fiber parts were selected to design the proposed structure of this biomechanical leg, which is to be manufactured in the Mechanical Lab of the Sultan Qaboos University (SQU). The capabilities of the designed leg to perform the normal human walking are presented. This study provides a noteworthy and unique design for the passive toe joint, represented by a mass-spring damper system, using torsion springs in the foot segment. The working principle and characteristics of the passive toe joint are discussed.  Four-designed cases, with different design parameters, for the passives toe joint system are presented to address the significant role that the passive toe joint plays in human-like motion. The dynamic motion that is used to conduct this comparison was the first stage of the stance motion. The advantages of the presence of the passive toe joint in gait, and its effect on reducing the energy consumption by the other actuated joints are presented and a comparison between the four-designed cases is discussed.

scholarly journals Robot Control Using Alternative Trajectories Based on Inverse Errors in the Workspace

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Quoc Khanh Duong ◽  
Thanh Trung Trang ◽  
Thanh Long Pham
Keyword(s):  
Control System ◽  
High Resolution ◽  
Robot Control ◽  
Low Cost ◽  
Transmission System ◽  
Measuring System ◽  
Robot Calibration ◽  
Measuring Device ◽  
Calibration Solution ◽  
System Errors

It is easy to realize that most robots do not move to the desired endpoint (Tool Center Point (TCP)) using high-resolution noncontact instrumentation because of manufacturing and assembly errors, transmission system errors, and mechanical wear. This paper presents a robot calibration solution by changing the endpoint trajectories while maintaining the robot’s control system and device usages. Two independent systems to measure the endpoint positions, the robot encoder and a noncontact measuring system with a high-resolution camera, are used to determine the endpoint errors. A new trajectory based on the measured errors will be built to replace the original trajectory. The results show that the proposed method can significantly reduce errors; moreover, this is a low-cost solution and easy to apply in practice and calibration can be done cyclically. The only requirement for this method is a noncontact measuring device with high-resolution and located independently with the robot in calibration.

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