Performance evaluation of accelerometers ADXL345 and MPU6050 exposed to random vibrational input

The use of vibration monitors is a well-established practice in industrial maintenance, usually vibration sensors are positioned at specific points on the monitored machinery and data are continuously collected to feed a machine operating health control system. Nevertheless, the technology for obtaining the signal, its treatment and analysis is generally expensive, and the financial return is not evident, which justifies the development of low-cost alternatives technologies. In this work was performed an analysis of the responses of two Micro-Electro-Mechanical accelerometers, models ADXL345 and MPU6050, exposed to a low intensity random signal and standard operating frequency. The objective of the analysis was to verify the capacity of these devices to be used as mechanical vibration sensors for rotating machines. For this purpose, offset shift analyzes of the sensors due to the Earth's gravitational field were performed, as well as vibrational spectrum and rectification errors analysis under multiple conditions. The data pointed to a greater uniformity of the MPU6050 response, while several behavioral anomalies were seen in the ADXL345, when these sensors are exposed to the same mechanical signal. The qualitative and quantitative behavior of MPU6050 rectification error was consistent with reported in the literature. It was noted that the methodology used can profile the behavior of sensors, however, it is not sufficient to safely justify the inaccuracies, requiring that the tests be performed on a statistically representative number of sensors from different manufacturers and batches.

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Design, manufacture and testing of a prototype obstacle-detection device at blind corners: an automated highway system technology

Transportation Safety and Environment ◽

10.1093/tse/tdaa029 ◽

2020 ◽

Author(s):

Charles Atombo ◽

Emmanuel Gbey ◽

Apevienyeku Kwami Holali

Keyword(s):

Traffic Accidents ◽

Low Cost ◽

Effective Area ◽

Obstacle Detection ◽

The Road ◽

Vibration Sensors ◽

Road Signs ◽

Sensor Module ◽

Vehicle Path ◽

Automated Highway

Abstract Traffic accidents on highways are attributed mostly to the "invisibility" of oncoming traffic and road signs. "Speeding" also causes drivers to reduce the effective radius of the vehicle path in the curve, thus trespassing into the lane of the oncoming traffic. The main aim of this paper was to develop a multisensory obstacle-detection device that is affordable, easy to implement and easy to maintain to reduce the risk of road accidents at blind corners. An ultrasonic sensor module with a maximum measuring angle of 15° was used to ensure that a significant portion of the lane was detected at the blind corner. The sensor covered a minimum effective area of 0.5 m2 of the road for obstacle detection. Yellow light was employed to signify caution while negotiating the blind corner. Two photoresistors (PRs) were used as sensors because of the limited number of pins on the microcontroller (Arduino Uno). However, the device developed for this project achieved obstacle detection at blind corners at relatively low cost and can be accessed by all road users. In real-world applications, the use of piezoelectric accelerometers (vibration sensors) instead of PR sensors would be more desirable in order to detect not only cars but also two-wheelers.

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Dual-Modal Assay Kit for the Qualitative and Quantitative Determination of the Total Water Hardness Using a Permanent Marker Fabricated Microfluidic Paper-Based Analytical Device

Chemosensors ◽

10.3390/chemosensors8040097 ◽

2020 ◽

Vol 8 (4) ◽

pp. 97

Author(s):

Oyejide Damilola Oyewunmi ◽

Seyed Hamid Safiabadi-Tali ◽

Sana Jahanshahi-Anbuhi

Keyword(s):

Ethylenediaminetetraacetic Acid ◽

Limit Of Detection ◽

Low Cost ◽

Water Hardness ◽

Sample Introduction ◽

World Health ◽

Total Hardness ◽

Quantitative Detection ◽

Qualitative And Quantitative ◽

Analytical Device

A dip-and-read microfluidic paper-based analytical device (µPAD) was developed for the qualitative and quantitative detection of the total hardness of water. To create well-defined hydrophobic barriers on filter paper, a regular office printer and a commercially available permanent marker pen were utilized as a quick and simple technique with easily accessible equipment/materials to fabricate µPAD in new or resource-limited laboratories without sophisticated equipment. After a wettability and barrier efficiency analysis on the permanent marker colors, the blue and green ink markers exhibited favorable hydrophobic properties and were utilized in the fabrication of the developed test devices. The device had five reaction and detection zones modeled after the classification given by the World Health Organization (WHO), so qualitatively it determined whether the water was ‘soft’, ‘moderately hard’, ‘hard’, or ‘very hard’ by changing color from blue to pink in about 3 min. The device was also used to introduce an alternative colorimetric reaction for quantitative analysis of the water hardness without the need for ethylenediaminetetraacetic acid (EDTA) and without compromising the simplicity and low cost of the device. The developed µPAD showed a calculated limit of detection (LOD) of 0.02 mM, which is at least 80% less than those of commercially available test strips and other reported µPADs, and the results of the real-world samples were consistent with those of the standard titration (with EDTA). In addition, the device exhibited stability for 2 months at room and frigid condition (4 °C) and at varying harsh temperatures from 25 to 100 °C. The results demonstrate that the developed paper-based device can be used for rapid, on-site analysis of water with no interferences and no need for a pipette for sample introduction during testing.

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Design of a 3-RPR Flexure System for Optical Switch Assembly

Mathematical Problems in Engineering ◽

10.1155/2020/6758261 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9

Author(s):

Guiyue Kou ◽

Mouyou Lin ◽

Changbao Chu

Keyword(s):

Permanent Magnets ◽

Optical Switch ◽

Low Cost ◽

Mechanical Vibration ◽

Analytical Models ◽

Assembly System ◽

Sensors And Actuators ◽

Damping Force ◽

Element Analysis ◽

Compact Size

In the MEMS optical switch assembly, the collision is likely to happen between the optical fiber and the U-groove of the chip due to the uncontrollable assembly errors. However, these errors can hardly be completely eliminated by the active control using high precision sensors and actuators. It will cause the large acting force and part damage, which further leads to the assembly failure. To solve this question, this paper presents a novel low-cost three-degree-of-freedom (three-DOF) passive flexure system to adaptively eliminate the planar assembly errors. The flexure system adopts three parallel kinematic chains with a novel 3-RPR structure and has a compact size with a diameter of 125 mm and thickness of 12 mm. A novel eddy current damper with the structure of Halbach array permanent magnets (PMs) is utilized to suppress the adverse mechanical vibration of the assembly system from the background disturbances. Analytical models are established to analyze the kinematic, static, and dynamic performances of the system in detail. Finally, finite element analysis is adopted to verify the established models for optimum design. The flexure system can generate a large deformation of 1.02 mm along the two translational directions and 0.02° along the rotational direction below the yield state of the material, and it has much higher natural frequencies than 200 Hz. Moreover, the large damping force means that the designed ECD can suppress the system vibration quickly. The above results indicate the excellent characteristics of the assembly system that will be applied into the optical switch assembly.

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An integrated vision-based system for efficient robot arm teleoperation

Industrial Robot the international journal of robotics research and application ◽

10.1108/ir-06-2020-0129 ◽

2020 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Xin Wu ◽

Canjun Yang ◽

Yuanchao Zhu ◽

Weitao Wu ◽

Qianxiao Wei

Keyword(s):

Pose Estimation ◽

Low Cost ◽

Extraction Process ◽

Robot Arm ◽

Mapping Procedure ◽

Content Type ◽

Qualitative And Quantitative ◽

Motion Constraints ◽

Teleoperation System ◽

Human Pose

Purpose This paper aims to present a natural human–robot teleoperation system, which capitalizes on the latest advancements of monocular human pose estimation to simplify scenario requirements on heterogeneous robot arm teleoperation. Design/methodology/approach Several optimizations in the joint extraction process are carried on to better balance the performance of the pose estimation network. To bridge the gap between human joint pose in Cartesian space and heterogeneous robot joint angle pose in Radian space, a routinized mapping procedure is proposed. Findings The effectiveness of the developed methods on joint extraction is verified via qualitative and quantitative experiments. The teleoperation experiments on different robots validate the feasibility of the system controlling. Originality/value The proposed system provides an intuitive and efficient human–robot teleoperation method with low-cost devices. It also enhances the controllability and flexibility of robot arms by releasing human operator from motion constraints, paving a new way for effective robot teleoperation.

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A Combination of a Vibrational Electromagnetic Energy Harvester and a Giant Magnetoimpedance (GMI) Sensor

Sensors ◽

10.3390/s20071873 ◽

2020 ◽

Vol 20 (7) ◽

pp. 1873

Author(s):

Juan Jesús Beato-López ◽

Isaac Royo-Silvestre ◽

José María Algueta-Miguel ◽

Cristina Gómez-Polo

Keyword(s):

Permanent Magnets ◽

Energy Harvester ◽

Vibrational Energy ◽

Magnetic Levitation ◽

Low Cost ◽

Mechanical Vibration ◽

Inertial Mass ◽

Amorphous Wire ◽

Magnetic Element ◽

Giant Magnetoimpedance

An energy harvesting device combined with a giant magnetoimpedance (GMI) sensor is presented to analyze low frequency vibrating systems. An electromagnetic harvester based on magnetic levitation is proposed for the electric power generation. The device is composed of two fixed permanent magnets at both ends of a cylindrical frame, a levitating magnet acting as inertial mass and a pick-up coil to collect the induced electromotive force. At the resonance frequency (10 Hz) a maximum electrical power of 1.4 mW at 0.5 g is generated. Moreover, an amorphous wire was employed as sensor nucleus for the design of a linear accelerometer prototype. The sensor is based on the GMI effect where the impedance changes occur as a consequence of the variations of the effective magnetic field due to an oscillating magnetic element. As a result of the magnet’s periodic motion, an amplitude modulated signal (AM) was obtained, its amplitude being proportional to mechanical vibration amplitude (or acceleration). The sensor’s response was examined for a simple ferrite magnet under vibration and compared with that obtained for the vibrational energy harvester. As a result of the small amplitudes of vibration, a linear sensor response was obtained that could be employed in the design of low cost and simple accelerometers.

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Research on the Distributings of Vibration Sensors for Fault Diagnosis in Axial Piston Pump

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.472-475.1155 ◽

2012 ◽

Vol 472-475 ◽

pp. 1155-1159

Author(s):

Sheng Qiang Wu ◽

Cai Qin Liu ◽

Er Ling Cao

Keyword(s):

Experimental Data ◽

Fault Diagnosis ◽

Research Result ◽

Mechanical Vibration ◽

Strong Support ◽

Piston Pump ◽

Axial Piston Pump ◽

Vibration Sensors ◽

Axial Piston ◽

Feature Frequency

Considering that the distributings of sensors will affect the fault diagnosis results directly, how to distribute vibration sensors for fault diagnosis in axial piston pump are researched. The corresponding feature frequency bands of various faults are analyzed, effects of collecting signals are compared in differrent fixings of vibration sensors, placements scheme of the sensors is proposed. Combined with the experimental data, the best distributings of vibration sensors is obtained. Research result provide a strong support in the pump monitoring and fault diagnosis field and reference in other complex mechanical vibration fault diagnosis field.

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Minimising the risk of Mycobacterium chimaera infection during cardiopulmonary bypass by the removal of heater-cooler units from the operating room

Perfusion ◽

10.1177/0267659117739103 ◽

2017 ◽

Vol 33 (4) ◽

pp. 264-269 ◽

Cited By ~ 3

Author(s):

Thomas A. Barker ◽

Uday Dandekar ◽

Nina Fraser ◽

Lincoln Dawkin ◽

Paul Sweeney ◽

...

Keyword(s):

Cardiopulmonary Bypass ◽

Operating Room ◽

Low Cost ◽

Airborne Bacteria ◽

Contaminated Water ◽

Dual Purpose ◽

Standard Operating ◽

Life Threatening ◽

Surgical Field ◽

Circuit Function

Introduction: Mycobacterium chimaera ( M. chimaera) is a recently characterised bacterium that can cause life-threatening infections in small numbers of patients who undergo cardiopulmonary bypass during cardiac surgery. The likely mode of transmission is thought to occur through aerosolisation from contaminated water reservoirs. The airborne bacteria then contaminate the surgical field, leading to an infection months or even years later. The preferred practical solution to disrupt the transmission of these airborne bacteria to the patient is to remove the heater-cooler units (HCUs) from the operating room (OR). We describe a process of achieving this in order to provide information to guide other institutions who wish to do a similar thing. Methods: A multidisciplinary team was assembled to work on the project. The planning phase involved trialling different OR layouts and simulating the alterations in the HCU circuit function. The changes to the OR were made over a weekend to minimise disruption to the operating schedule. Results: The HCU was moved to the dirty utility room adjacent to the OR. Standard operating procedures (SOP) and risk assessments were made to enable this to be used for a dual purpose. One of the ORs was reconfigured to allow the cardiopulmonary bypass machine to be located close to the HCU in the dirty utility room. The total cost of the alterations was £6,158. Although we have provided a physical barrier to interrupt patient exposure to aerosolised M. chimaera from HCUs, we continue to perform cultures and decontamination as per the national recommendations. The SOP was designed to be auditable to ensure compliance with the protocols. Conclusions: We show a method by which the HCU can be removed from the OR in a relatively low-cost, straightforward and practical manner.

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Standard operating procedures improve acute neurologic care in a sub-Saharan African setting

Neurology ◽

10.1212/wnl.0000000000004080 ◽

2017 ◽

Vol 89 (2) ◽

pp. 144-152 ◽

Cited By ~ 4

Author(s):

Lamin E.S. Jaiteh ◽

Stefan A. Helwig ◽

Abubacarr Jagne ◽

Andreas Ragoschke-Schumm ◽

Catherine Sarr ◽

...

Keyword(s):

Emergency Management ◽

Low Cost ◽

Intervention Group ◽

Vital Signs ◽

Standard Operating Procedures ◽

Sub Saharan Africa ◽

Standard Operating ◽

Sub Saharan ◽

Neurologic Emergency

Objective:Quality of neurologic emergency management in an under-resourced country may be improved by standard operating procedures (SOPs).Methods:Neurologic SOPs were implemented in a large urban (Banjul) and a small rural (Brikama) hospital in the Gambia. As quality indicators of neurologic emergency management, performance of key procedures was assessed at baseline and in the first and second implementation years.Results:At Banjul, 100 patients of the first-year intervention group exhibited higher rates of general procedures of emergency management than 105 control patients, such as neurologic examination (99.0% vs 91.4%; p < 0.05) and assessments of respiratory rate (98.0% vs 81.9%, p < 0.001), temperature (60.0% vs 36.2%; p < 0.001), and glucose levels (73.0% vs 58.1%; p < 0.05), in addition to written directives by physicians (96.0% vs 88.6%, p < 0.05), whereas assessments of other vital signs remained unchanged. In stroke patients, rates of stroke-related procedures increased: early CT scanning (24.3% vs 9.9%; p < 0.05), blood count (73.0% vs 49.3%; p < 0.01), renal and liver function tests (50.0% vs 5.6%, p < 0.001), aspirin prophylaxis (47.3% vs 9.9%; p < 0.001), and physiotherapy (41.9% vs 4.2%; p < 0.001). Most effects persisted until the second-year evaluation. SOP implementation was similarly feasible and beneficial at the Brikama hospital. However, outcomes did not significantly differ in the hospitals.Conclusions:Implementing SOPs is a realistic, low-cost option for improving process quality of neurologic emergency management in under-resourced settings.Classification of evidence:This study provides Class IV evidence that, for patients with suspected neurologic emergencies in sub-Saharan Africa, neurologic SOPs increase the rate of performance of guideline-recommended procedures.

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Efficient and Rapid Detection ofSalmonellaUsing Microfluidic Impedance Based Sensing

Journal of Sensors ◽

10.1155/2015/293461 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 28

Author(s):

Shibajyoti Ghosh Dastider ◽

Syed Barizuddin ◽

Nuh S. Yuksek ◽

Majed Dweik ◽

Mahmoud F. Almasri

Keyword(s):

Salmonella Typhimurium ◽

Low Cost ◽

Electrode Array ◽

Interdigitated Electrode ◽

Qualitative And Quantitative ◽

Impedance Response ◽

Lower Detection ◽

Microfluidic Biosensor ◽

Increased Sensitivity ◽

Quantitative Results

We present a low cost, easy to fabricate biosensor, which can quickly and accurately detectSalmonella typhimurium. This study also compares the advantages of the microfluidic biosensor over a nonmicrofluidic biosensor. High density interdigitated electrode array was used to detectSalmonellacells inside a microfluidic chip. Monoclonal anti-Salmonellaantibodies were allowed to be immobilized on the surface of the electrode array for selective detection ofSalmonella typhimurium. An impedance analyzer was used to measure and record the response signal from the biosensor. The biosensor provides qualitative and quantitative results in 3 hours without any enrichment steps. The microfluidic biosensor’s lower detection limit was found to be3×103 CFU/mL compared to the3×104 CFU/mL of the nonmicrofluidic biosensor, which shows that the microfluidic biosensor has 10-fold increased sensitivity. The impedance response of microfluidic biosensor was also significantly higher (2 to 2.9 times) compared to the nonmicrofluidic biosensor.

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