scholarly journals Suppression of Noise to Obtain a High-Performance Low-Cost Optical Encoder

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Sergio Alvarez-Rodríguez ◽  
Noé Alcalá-Ochoa ◽  
Javier Cruz-Salgado ◽  
Francisco Gerardo Peña Lecona

Currently, commercial encoders endowed with high precision are expensive sensors, and optical low-cost designs to measure the positioning angle have undesirable levels of system noise which reduce the good performance of devices. This research is devoted to the designing of mathematical filters to suppress noise in polarized transducers, in order to obtain high accuracy, precision, and resolution, along with an adaptive maximum response speed for low-cost optical encoders. This design was proved through a prototype inside a research platform, and experimental results show an accuracy of 3.9, a precision of 26, and a resolution of 17 [arc seconds], at least for the specified working conditions, for the sensing of the angular position of a rotary polarizer. From this work has been obtained a high-performance low-cost polyphase optical encoder, which uses filtering mathematical principles potentially generalizable to other inventions.

2019 ◽  
Vol 72 (04) ◽  
pp. 917-930
Author(s):  
Fang-Shii Ning ◽  
Xiaolin Meng ◽  
Yi-Ting Wang

Connected and Autonomous Vehicles (CAVs) have been researched extensively for solving traffic issues and for realising the concept of an intelligent transport system. A well-developed positioning system is critical for CAVs to achieve these aims. The system should provide high accuracy, mobility, continuity, flexibility and scalability. However, high-performance equipment is too expensive for the commercial use of CAVs; therefore, the use of a low-cost Global Navigation Satellite System (GNSS) receiver to achieve real-time, high-accuracy and ubiquitous positioning performance will be a future trend. This research used RTKLIB software to develop a low-cost GNSS receiver positioning system and assessed the developed positioning system according to the requirements of CAV applications. Kinematic tests were conducted to evaluate the positioning performance of the low-cost receiver in a CAV driving environment based on the accuracy requirements of CAVs. The results showed that the low-cost receiver satisfied the “Where in Lane” accuracy level (0·5 m) and achieved a similar positioning performance in rural, interurban, urban and motorway areas.


Author(s):  
Christoph Sosna ◽  
Rainer Buchner ◽  
Walter Lang ◽  
Wolfgang Benecke ◽  
Christian Boehm ◽  
...  

In this paper a feasibility study of a micromachined PQT-sensor for measurement of pressure (P), flow rate (Q), and temperature (T) for diagnostic applications in pneumatic systems is presented. As a low cost device this innovative PQT-sensor has to fulfill different kinds of criteria such as wide measuring range, fast response time, high resolution and high accuracy for diagnosing the health status of a pneumatic system. By using micro electro mechanical systems (MEMS) technologies small high-performance sensors were fabricated which fulfill all these criteria. At first, principles will be described that have been chosen for measurement of pressure, flow and temperature that will be used for the PQT-sensor. A design proposal for the sensor will be presented and verified with analytical calculations to show its applicability.


1970 ◽  
Vol 4 ◽  
pp. 5-6
Author(s):  
Alejandro Márquez ◽  
Nicolás Medrano ◽  
Belén Calvo ◽  
Pedro A. Martínez

This paper presents a CMOS 1.8V-180nm analog quadrature sine oscillator. Thanks to a custom 12-bit bidirectional DAC-based architecture, the frequency can be digitally programmed over two decades with high accuracy, making it suitable as the actuation system in low-cost high-performance embedded lock-in measurement systems.


2015 ◽  
Vol 730 ◽  
pp. 3-10
Author(s):  
Jun Du ◽  
Zhi Rong Mei ◽  
Li Lei Fu ◽  
Kui Zhang

Since numerical simulation method came out, it has caused a great importance to tunnel engineers and has been used widely. But it has been restricted in three-dimensional numerical analysis of multi-element and multi-working conditions because the out of memory of personal computer, the high cost of high-performance computer and so on. In view of this, we need to search the low-cost computing devices to solve the large-scale three-dimensional numerical simulation in tunnel engineering. After investigation and study, we have built a Linux-based PC cluster system successfully, and use it to simulate the excavation process of Xiamen Jiaheyuan underground access which is a rectangular shallow buried soft soil tunnel. The simulation results provide a basis for the construction. Linux-based PC cluster system provides a convenient and cheap solution for tunnel engineers in three-dimensional numerical simulation of multi-element and multi-working conditions.


2020 ◽  
Vol 16 (3) ◽  
pp. 246-253
Author(s):  
Marcin Gackowski ◽  
Marcin Koba ◽  
Stefan Kruszewski

Background: Spectrophotometry and thin layer chromatography have been commonly applied in pharmaceutical analysis for many years due to low cost, simplicity and short time of execution. Moreover, the latest modifications including automation of those methods have made them very effective and easy to perform, therefore, the new UV- and derivative spectrophotometry as well as high performance thin layer chromatography UV-densitometric (HPTLC) methods for the routine estimation of amrinone and milrinone in pharmaceutical formulation have been developed and compared in this work since European Pharmacopoeia 9.0 has yet incorporated in an analytical monograph a method for quantification of those compounds. Methods: For the first method the best conditions for quantification were achieved by measuring the lengths between two extrema (peak-to-peak amplitudes) 252 and 277 nm in UV spectra of standard solutions of amrinone and a signal at 288 nm of the first derivative spectra of standard solutions of milrinone. The linearity between D252-277 signal and concentration of amironone and 1D288 signal of milrinone in the same range of 5.0-25.0 μg ml/ml in DMSO:methanol (1:3 v/v) solutions presents the square correlation coefficient (r2) of 0,9997 and 0.9991, respectively. The second method was founded on HPTLC on silica plates, 1,4-dioxane:hexane (100:1.5) as a mobile phase and densitometric scanning at 252 nm for amrinone and at 271 nm for milrinone. Results: The assays were linear over the concentration range of 0,25-5.0 μg per spot (r2=0,9959) and 0,25-10.0 μg per spot (r2=0,9970) for amrinone and milrinone, respectively. The mean recoveries percentage were 99.81 and 100,34 for amrinone as well as 99,58 and 99.46 for milrinone, obtained with spectrophotometry and HPTLC, respectively. Conclusion: The comparison between two elaborated methods leads to the conclusion that UV and derivative spectrophotometry is more precise and gives better recovery, and that is why it should be applied for routine estimation of amrinone and milrinone in bulk drug, pharmaceutical forms and for therapeutic monitoring of the drug.


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