scholarly journals Rotational Speed Measurement Based on LC Wireless Sensors

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 8055
Author(s):  
Yi Zhou ◽  
Lei Dong ◽  
Chi Zhang ◽  
Lifeng Wang ◽  
Qingan Huang

This article presents a method for detecting rotational speed by LC (inductor-capacitor) wireless sensors. The sensing system consists of two identical LC resonant tanks. One is mounted on the rotating part and the other, as a readout circuit, is placed right above the rotating part. When the inductor on the rotating part is coaxially aligned with the readout inductor during rotation, the mutual coupling between them reaches the maximum, resulting in a peak amplitude induced at the readout LC tank. The period of the readout signal corresponds to the rotation speed. ADS (Advanced Design System) software was used to simulate and optimize the sensing system. A synchronous detection circuit was designed. The rotational speed of an electric was measured to validate this method experimentally, and the results indicated that the maximum error of the rotation speed from 16 rps to 41 rps was 0.279 rps.

Author(s):  
Che Muhammad Ikram Che Umar ◽  
◽  
Mohd Fadhli Zulkafli ◽  

The prototype of UTHM C-Drone use a coaxial hexacopter concept for its propulsion system. A coaxial rotor consists of two motor and two propellers mounted above each other and aligned in relation to their axis of rotation. The propellers are based on the T-Motor U15XXL KV29 model used in UTHM C-Drone. The distance between the two propellers is usually relative to the radius of the propeller or can be lesser. The objectives for this study are to investigate the effect of distance between upper and lower propeller in a coaxial rotors system and the effect of rotational speed. This study is important to ensure the C-Drone power efficient and capable to lift 180 kg payload. The CAD model of the propeller and coaxial rotors system were designed based on the specification from T-Motor company by Solidworks software and the flow simulations were conducted using Solidworks Flow Simulation module. The total of six CAD models; one for a single propeller and five for coaxial rotors with five difference of distance cases were constructed. For each model, the total thrust was tested from 50% throttle power up to the 90% throttle power. It was found that the coaxial rotors system can generate more thrust than a single propeller but less than double. It was also found that if the lower propeller rotates faster than the upper propeller, the increment of total thrust is very small. However, if the upper propeller rotates faster than the lower propeller, the total thrust increase significantly. For the case of faster upper propeller, as the higher the throttle applied, the thrust increment ratio will decrease, and the efficiency of the thrust produced will be affected. In addition, for same rotation speed, the thrust generated was lesser when both propellers rotate in a same direction compared to when each propeller rotates in the opposite directions of each other.


2020 ◽  
Vol 18 (4) ◽  
pp. 299-303
Author(s):  
Tao Wang ◽  
Bicong Wang ◽  
Yuyi Chen ◽  
Yufeng Luo

There are few reports on high rotational speed measurement of brushless direct current (DC) motors based on giant magneto-inductive effect. In this study, a rotational speed measurement system based on giant magneto-inductive effect is established for measuring the rotational speeds of DC motors. Successive sawtooth waves are found when rotating shaft is close to the GMI sensor. Through using the magneto-inductive sensing system, different high rotational speeds (1500∼24000 r/min) of the motor are accurately measured. Therefore, this giant magneto-inductive sensor may be used for high rotational speed measurement of motors.


Author(s):  
Yousra Hamdy Farid

Cementation or metal displacement reaction is one of the most effective techniques for removing toxic metals from industrial waste solutions. Aims: The main purpose of this work is to study the rate of cementation of cadmium by using a rotating bed of Zn Raschig rings packed in a perforated impeller basket for the investigation of the removal of Cd 2+ from waste solution. Study Design: The reactor was tested for Cd2+ concentration removed, the diameter of Zinc Raschig rings, and the rotational speed of the basket. Methodology: The results indicate that there are two rates of cementation for Cd-Zn system, a high rate at the beginning, followed by a lower rate after the initial period. The results also show that percentage removal of Cd2+ ions from solution increases by increasing the speed of basket rotation, and as the diameter of Zn Raschig ring packed in the basket reactor, increases the removal of Cd2+ decreases. The cadmium deposits on zinc as powder. Results: The removal of Cd2+ is optimum for ring diameter of 0.5 cm, initial concentration of 100 ppm, and basket rotation speed of 500 rpm. The experimental data fit the following equation: Sh=0.041 Sc0.33Re0.40. This equation can be used for the design scale-up and operation of reactors used to remove Cd2+ from wastewater by cementation. Conclusion: Rates of cementation were expressed in terms of the rate of mass transfer, the mass transfer coefficient increases as the rotational speed of the basket increases.


2008 ◽  
Vol 70 (6) ◽  
pp. 639-644 ◽  
Author(s):  
Shinichi IMAFUKU ◽  
Juichiro NAKAYAMA ◽  
Taro MAKINO ◽  
Masaaki KOSAKA ◽  
Akiko KOZASA ◽  
...  

Proceedings ◽  
2021 ◽  
Vol 65 (1) ◽  
pp. 29
Author(s):  
Alessandro Pracucci ◽  
Sara Magnani ◽  
Laura Vandi ◽  
Oscar Casadei ◽  
Amaia Uriarte ◽  
...  

The nearly Zero Energy building (nZEB) renovation market is currently the key feature in the construction sector. RenoZEB aims to develop a systematic approach for retrofitting by assembling different technologies in a plug and play building envelope. This paper presents the methodology used to transform the RenoZEB concept in the design system. A multi-criteria decision matrix is used for the selection of the best façade technologies within the market while the analysis of the existing building conditions allows to develop a replicable approach for designing deep retrofitting intervention through a plug&play façade. The methodology appears to be a valuable support for the selection of technologies and allows to define a design guideline for the envelope.


2015 ◽  
Vol 9 (2) ◽  
pp. 249-258 ◽  
Author(s):  
Alessandro Cazzorla ◽  
Paola Farinelli ◽  
Laura Urbani ◽  
Fabrizio Cacciamani ◽  
Luca Pelliccia ◽  
...  

This paper presents the modeling, manufacturing, and testing of a micro-electromechanical system (MEMS)-based LC tank resonator suitable for low phase-noise voltage-controlled oscillators (VCOs). The device is based on a variable MEMS varactor in series with an inductive coplanar waveguide line. Two additional parallel stubs controlled by two ohmic MEMS switches have been introduced in order to increase the resonator tunability. The device was fabricated using the FBK-irst MEMS process on high resistivity (HR) silicon substrate. Samples were manufactured with and without a 0-level quartz cap. The radio frequency characterization of the devices without 0-level cap has shown a continuous tuning range of 11.7% and a quality factor in the range of 33–38. The repeatability was also tested on four samples and the continuous tuning is 11.7 ± 2%. Experimental results on the device with a 0-level cap, show a frequency downshift of about 200 MHz and a degradation of the quality factor of about 20%. This is, most likely, due to the polymeric sealing ring as well as to a contamination of the ohmic contacts introduced by the capping procedure. A preliminary design of a MEMS-based VCO was performed using Advanced Design System and a hardwired prototype was fabricated on Surface Mount Technology on RO4350 laminate. The prototype was tested resulting in a resonance frequency of 5 GHz with a phase noise of −105 and −126 dBc at 100 KHz and 1 MHz, respectively, and a measured output power of −1 dBm.


Author(s):  
Minoru Chino ◽  
Kenji Takizawa ◽  
Takashi Yabe

This paper provides the experimental results on skimmer and gives some detailed information useful for benchmark test of computer codes that are now able to simulate the fluid-structure interaction. For this purpose, we specially designed the injection system that imposes reproducible rotational speed and injection speed on the skipper. The effect of rotation is discussed by changing rotation speed in a wide range.


2011 ◽  
Vol 308-310 ◽  
pp. 538-541
Author(s):  
Yuan Chen

An effort is made to give a description of a computer-aided conceptual design system. A novel Function-Action-Behavior-Mechanism (FABM) modeling framework is proposed to realize mapping from the overall function to principle solution according to customer’s requirements. Expansion and modification rules in the demand behavior are developed to extend the innovation of principle solution. A case study on pan mechanism design for cooking robot is presented to show the procedure of how to implement the intelligent reasoning based on the FABM model.


Author(s):  
Deyi Xue

Abstract A global optimization approach for identifying the optimal product configuration and parameters is proposed to improve manufacturability measures including feasibility, cost, and time of production. Different product configurations, including alternative design candidates and production processes, are represented by an AND/OR graph. Product parameters are described by variables including continuous variables, integer variables, Boolean variables, and discrete variables. Two global optimization methods, genetic algorithm and simulated annealing, are employed for identifying the optimal product configuration and parameters. The introduced approach serves as a key component in an integrated concurrent design system. A case study example is given to show how the proposed method is used for solving the engineering problems.


2020 ◽  
Vol 18 (12) ◽  
pp. 889-893
Author(s):  
Kalyan Biswas

In this work, a simple but versatile sensing system for very accurate sensing of liquid level and liquid density is presented. The sensor works based on basic strain sensitivity of Fiber Bragg Grating (FBG) and principle of liquid obeying Archimedes’ law of buoyancy. In this system, a cylindrical shaped mass suspended from a Fiber Bragg Grating and partially immersed in the liquid to be sensed. If the liquid level in the container or liquid density varies, that change the up thrust on the suspended mass and load on the Fiber will be changed accordingly. The change in the load on Fiber changes strain on the FBG and the reflected Bragg wavelength also changes. The proposed device with proper calibration should be able to carry out real time and nonstop liquid level and liquid density measurements. A mathematical analysis of the system considering liquid properties and geometrical structure of the suspended mass is presented here. Sensitivity of the system for liquid level monitoring is also reported. Achieved results shows the path for the utilization of the proposed sensor system for precise liquid density measurement and liquid level sensing in very large storage tanks used for commercial/residential applications.


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