scholarly journals Design and Implementation of a Novel Tilt Sensor Based on the Principle of Variable Reluctance

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5228
Author(s):  
Lei Guo ◽  
Lishuai Zhang ◽  
Yuan Song ◽  
Liang Zhao ◽  
Qiancheng Zhao
Keyword(s):  
Experimental Data ◽  
Dynamic Systems ◽  
Tilt Angle ◽  
Electrical Signal ◽  
Measurement Unit ◽  
Square Wave ◽  
Variable Reluctance ◽  
Sensor Structure ◽  
Tilt Sensor ◽  
Translational Acceleration

Tilt angle measurement in dynamic systems is problematic because the rotation of the measured platform is coupled with translation. Therefore, when some sensors are applied in dynamic systems, their output signals are often submerged in the noise signals generated by translation. To enhance the ability of tilt sensors to resist translational noise, a dynamic tilt sensor is proposed based on the principle of variable reluctance from the perspective of sensor structure. The eccentric structure of the sensor constructed with a shell, liquid, and internal damping plate was designed according to the principles of mechanics. The characteristic of translational acceleration restraint determined by the sensor structure was established theoretically. In addition, the magnetic circuit of the sensor was analyzed to illustrate the sensor’s working principles. A Clapp oscillator circuit was designed to convert mechanical motion into a measureable electrical signal. A method to determine the sensor’s direction of rotation is proposed. A waveform conversion circuit was designed to convert the sine wave output of the Clapp oscillator to a square wave, and a square-wave frequency measurement circuit was designed based on the C8051 micro-control unit. A translation–rotation experimental hardware platform was constructed. The data acquisition program was designed on a PC platform, and the translation–rotation experiments were conducted with an MTi attitude measurement unit as a reference. The validity of the tilt angle measurements and the effect of the translational acceleration restraint of the sensor were verified by the experimental data. The theoretical results obtained were consistent with the experimental data, verifying the validity of the theoretical analysis and experimental devices employed. A measurement range of −180 to 180° was achieved.

scholarly journals Electrophysical properties and transfer function of the vestibular labyrinth

2020 ◽  
pp. 154-161
Author(s):  
V.P. Demkin ◽  
◽  
S.V. Melnichuk ◽  
M.D. Akinina ◽  
O.V. Demkin ◽  
...  
Keyword(s):  
Experimental Data ◽  
Transfer Function ◽  
Dynamic Systems ◽  
Theoretical Study ◽  
Semicircular Canals ◽  
Electrical Signal ◽  
Electrophysical Properties ◽  
Posterior Semicircular Canal ◽  
Vestibular Labyrinth ◽  
Conductive Properties

We carried out an experimental and theoretical study of the electrical conductive properties of the tissues of the vestibular labyrinth. Using the theory of dynamic systems and experimental data on measurements of the amplitudes of the electrical signal at the end of the vestibular nerve, we calculated the transfer function of the vestibular labyrinth and investigated its frequency dependence. It is shown the transfer function tends to its asymptotic value with increasing frequency. We found that the transfer function of the vestibular labyrinth for stimulating impulses emanating from the electrode located in the posterior semicircular canal is significantly less than for stimulating impulses from the electrodes located in the superior and horizontal semicircular canals.

ON AN ORIENTATION TRANSITION IN NEMATIC LIQUID CRYSTALS INDUCED BY THE THICKNESS OF THE SAMPLE

1993 ◽  
Vol 07 (18) ◽  
pp. 1215-1222
Author(s):  
A. L. ALEXE-IONESCU
Keyword(s):  
Experimental Data ◽  
Phase Transitions ◽  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Tilt Angle ◽  
Critical Thickness ◽  
Large Range ◽  
Square Root ◽  
Chiral Molecules ◽  
Homeotropic Orientation

An orientation transition observed in nematic liquid crystal samples, induced by the thickness, is interpreted in a new way. By supposing that the nematic liquid crystal contains chiral impurities, it is shown that the homeotropic orientation is stable only for thicknesses smaller than a critical one, and is dependent on the concentration of the chiral molecules. At the critical thickness, the transition from the homeotropic orientation to the distorted one is characterized by a tilt angle proportional to the square root of the actual thickness minus the critical one. This trend is typical of second order phase transitions. The agreement between the theory and the experimental data is fairly good over a large range of thickness of the sample.

Model Verification of Mixed Dynamic Systems

1978 ◽  
Vol 100 (2) ◽  
pp. 266-273 ◽  
Author(s):  
J. D. Chrostowski ◽  
D. A. Evensen ◽  
T. K. Hasselman
Keyword(s):  
Experimental Data ◽  
Parameter Estimation ◽  
Dynamic Systems ◽  
Statistical Parameter ◽  
Model Verification ◽  
Passive Networks ◽  
Parameter Values ◽  
Basic Configuration ◽  
General Method

A general method is presented for using experimental data to verify math models of “mixed” dynamic systems. The term “mixed” is used to suggest applicability to combined systems which may include interactive mechanical, hydraulic, electrical, and conceivably other types of components. Automatic matrix generating procedures are employed to facilitate the modeling of passive networks (e.g., hydraulic, electrical). These procedures are augmented by direct matrix input which can be used to complement the network model. The problem of model verification is treated in two parts; verification of the basic configuration of the model and determination of the parameter values associated with that configuration are addressed sequentially. Statistical parameter estimation is employed to identify selected parameter values, recognizing varying degrees of uncertainty with regard to both experimental data and analytical results. An example problem, involving a coupled hydraulic-mechanical system, is included to demonstrate application of the method.

scholarly journals Combining Experimental Data and Computational Methods for the Non-Computer Specialist

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4783
Author(s):  
Reinier Cárdenas ◽  
Javier Martínez-Seoane ◽  
Carlos Amero
Keyword(s):  
Experimental Data ◽  
Molecular Mechanism ◽  
Computational Methods ◽  
Dynamic Systems ◽  
Experimental Methods ◽  
Computational Techniques ◽  
Biological Macromolecules ◽  
Basic Principles ◽  
Structural Interpretation

Experimental methods are indispensable for the study of the function of biological macromolecules, not just as static structures, but as dynamic systems that change conformation, bind partners, perform reactions, and respond to different stimulus. However, providing a detailed structural interpretation of the results is often a very challenging task. While experimental and computational methods are often considered as two different and separate approaches, the power and utility of combining both is undeniable. The integration of the experimental data with computational techniques can assist and enrich the interpretation, providing new detailed molecular understanding of the systems. Here, we briefly describe the basic principles of how experimental data can be combined with computational methods to obtain insights into the molecular mechanism and expand the interpretation through the generation of detailed models.

Cyclic single drop square wave polarography at spherical electrodes — the reversible case

1987 ◽  
Vol 65 (5) ◽  
pp. 1025-1032 ◽  
Author(s):  
Louis Ramaley ◽  
Wee Tee Tan
Keyword(s):  
Experimental Data ◽  
Square Wave Voltammetry ◽  
Simple Theory ◽  
Forward Peak ◽  
Single Drop ◽  
Peak Potential ◽  
Square Wave ◽  
Wave Voltammetry ◽  
Plane Theory ◽  
Best Fit

The influence of electrode sphericity and the results of sweep reversal are examined for square wave voltammetry and the square wave polarography in which an entire polarogram is obtained on a single drop. An expanding sphere treatment obtained by adding a spherical correction to expanding plane theory gives the best fit to the experimental data. Amalgam forming reactions fit the simple theory developed to a lesser extent than other reactions, especially on the reverse sweep. The shape of the differential polarogram is not significantly affected by sphericity and the reverse peak potential is approximately equal to the forward peak potential. Small differences in these potentials are due to the distortion of the square wave by the stairstep used for the sweep and the distortion of the polarogram due to drop growth. The ratio of the forward and reverse peak currents depends on the phasing of the square wave and stairstep in all cases and on other parameters for a growing drop.

A Low-Cost, High Rate Motion Software Sensor System Based on Novel Data Fusion for Unmanned Surface Vehicle Navigation and Oceanographic Instrumentation Motion Correction

2011 ◽  
Author(s):  
Chrystel R. Gelin ◽  
Nikolaos I. Xiros
Keyword(s):  
Data Fusion ◽  
Low Cost ◽  
Underwater Vehicles ◽  
High Rate ◽  
Measurement Unit ◽  
Vehicle Navigation ◽  
Gps Receiver ◽  
Unmanned Surface Vehicle ◽  
Flux Gate ◽  
Tilt Sensor

One of the major challenges in the navigation of underwater vehicles is obtaining precise and reliable positioning updates. Dead-Reckoning aided with Doppler velocity measurement has been, and remains, the most common method for underwater navigation for small vehicles. DR uses a set of navigation instruments to estimate the position of the vehicle by integrating the body-fixed velocity, accelerations, and angular rates with respect to time. Instrument error and bias lead to position error that increases exponentially with time. Thus, current DR systems require frequent position recalibrations. The Global Positioning System (GPS) provides measurements of geodetic coordinates for air and surface vehicles and it is often used to correct positioning error. However, underwater vehicles cannot use GPS for inflight navigation because GPS signals only penetrate a few centimeters past the air-sea interface. Thus, underwater vehicle navigation systems are limited to periodic position update from the GPS when they surface and extend an antenna through the air-sea interface. Standard GPS receivers are unable to provide the rate or precision required when used on a small vessel such as an Unmanned Surface Vehicle (USV). To overcome this, a low cost high rate motion measurement system for an USV with underwater and oceanographic purposes is proposed. The proposed onboard system for the USV consists of an Inertial Measurement Unit (IMU) with accelerometers and rate gyros, a GPS receiver, a flux-gate compass, a roll and tilt sensor and an ADCP. Interfacing all the sensors proved rather challenging because of their different characteristics. Some of the instruments have digital output (Compass/ADCP/GPS) while others have an analog output (IMU/tilt sensor). The proposed data fusion technique integrates the IMU, GPS receiver, flux-gate compass as well as tilt sensor and develops an embeddable software package, using real time data fusion methods, for a USV to aid in navigation and control as well as controlling an onboard Acoustic Doppler Current Profiler (ADCP). While ADCPs non-intrusively measure water flow, they suffer from the inability to distinguish between motions in the water column and self-motion. Thus, the vessel motion contamination needs to be removed to analyze the data and the system developed in this text provides the motion measurements and processing to accomplish this task.

Flow Similarity Applied in Convection-Based Tilt Sensor

2007 ◽  
Author(s):  
Shiliu Peng ◽  
Yonghong Zheng
Keyword(s):  
Heat Source ◽  
Temperature Difference ◽  
Tilt Angle ◽  
Temperature Drift ◽  
Perpendicular Line ◽  
Environment Temperature ◽  
Tilt Sensor ◽  
Line Cross ◽  
Flow Similarity ◽  
Tilt Sensors

The environment temperature has inevitable effects on property of the convection-based tilt sensors. It not only redefines the application, but also prevents the improvement of the sensor performance. Numerical simulation of the fluid flow in the chamber of a sensor was performed and the influence of the environment temperature was studied in this paper. At zero tilt angle, the temperature distribution along the perpendicular line cross the heat source at various environment temperatures was presented. It was found that the flow varied dramatically at different environment temperatures, which would cause the output signal vary accordingly, even when the tilt angle was kept at a constant, because this device works by sensing the change of flow. At the same condition, we present the numerical results when the temperature difference across the heat source and the environment was kept at the same, in those results, it was found that the temperature difference at every point along the perpendicular line cross the heat source keep the same, this result confirms the similarity principle of nature convection. Second, A method of eliminating environment temperature infect on property of convection-based tilt sensor, which is based on the theory of flow similarity, is proposed. It was found that a thermal transistance can be piped on the circuit of heat source to compensate the temperature of the heat source. A compensative circuit was specially designed which can keep flow similarity by changing heat source temperature in order to eliminate the influence of environment temperature. The experiment results show that above 70% temperature drift can be eliminated by this compensative circuit.

X-RAY INVESTIGATION ON TEMPERATURE DEPENDENCE OF THE TILT ANGLE IN FERROELECTRIC LIQUID CRYSTALS

1989 ◽  
Vol 03 (16) ◽  
pp. 1247-1250 ◽  
Author(s):  
XIANG ZHANG ◽  
ZHENGMIN SUN ◽  
DUAN FENG ◽  
GUOZHEN LI
Keyword(s):  
Experimental Data ◽  
Liquid Crystals ◽  
Critical Exponent ◽  
Temperature Dependence ◽  
Tilt Angle ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Ferroelectric Liquid Crystals ◽  
X Ray

The temperature dependence of the molecular tilt angle in a series of ferroelectric liquid crystals is deduced from X-ray diffraction measurement. The critical exponent β has been estimated from the experimental data. The non-classical value of β for the compounds lies in the range 0.36–0.41.

An Experimental Study of Natural Convection in Trapezoidal Enclosures

1980 ◽  
Vol 102 (4) ◽  
pp. 648-653 ◽  
Author(s):  
L. Iyican ◽  
L. C. Witte ◽  
Y. Bayazitogˇlu
Keyword(s):  
Experimental Data ◽  
Natural Convection ◽  
Rayleigh Number ◽  
Tilt Angle ◽  
Circulation Pattern ◽  
Two Dimensional ◽  
Number Range ◽  
Rectangular Channels ◽  
Trapezoidal Enclosure ◽  
Hot Surface

Experimental data for natural convection of air in an inclined trapezoidal enclosure are reported for a Rayleigh number range of ∼ 2 × 103 to ∼ 5 × 107. The small side of the trapezoid was electrically heated while the opposing large side was cooled to a uniform temperature. The effect of tilt angle from 0 to 90 deg (from horizontal) was investigated at 15 deg increments. Data were also obtained for 180 deg (hot surface facing down). A comparison of the data to an analysis using a two-dimensional circulation pattern showed reasonable agreement in the Rayleigh number-tilt angle range where two-dimensional circulation could be expected. The experimental data are correlated by an equation of the form, Nu = C Ran, over a wide Rayleigh number range. The data exhibit a local minimum in the Nusselt number-tilt angle curve between 90 and 0 deg in a manner similar to that observed in inclined rectangular channels.

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