Longitudinal Angle Research Articles

Different Autopilot Systems Design For a Small Fixed Wing Unmanned Aerial Vehicle

The aim of this study is to design an autopilot system for Unmanned Aerial Vehicle (UAV) in a small size and to compare the efficiency of the systems designed with different methods. For this purpose, linearized equations of motion for a small size UAV has beeen firstly obtained. Then the state space equations are used to check the stability characteristics of the UAV. Using the classical method, the longitudinal pitch angle, altitude and speed controller are designed for separate transfer functions according to the location curve of the roots and the desired response values. PID values were determined by considering the response of the system using classical methods. On the other hand, a feedback control system has been designed to improve the stability of different lines. And also an orientation controller has been designed. New approach proposed in the study is Adaptive Network Based Fuzzy Inference Systems (ANFIS) controller. In this study, a new controller approach based on fuzzy logic is proposed. Four data sets, PID control inputs and control sign have been obtained for the design of the proposed controller. These data sets have been used for training the fuzzy controller. As a result; It is presented with graphs that the proposed method is applicable and gives successful results.

CONTROL WITH REDUCING OF DISTURBING FACTORS

The structural and dynamic features of the space (moving outside the dense layers of the atmosphere) stages of rockets - carriers of spacecraft as control objects are analyzed. The reasons are investigated - disturbing factors that generate external forces and moments that determine the disturbed motion of space rocket stages. For space rocket stages, disturbing factors are: mass asymmetry of the stage relative to its longitudinal axis and angle of mismatch of the line of action of the thrust vector of the propulsion system of the stage with the longitudinal axis of the stage. It is shown that when using the stage control deviating in the hinge of the marching engine as the executive organs of the control system, the effect of auto-reduction of the mentioned disturbing factors arises. The consequence of the autocompensation of disturbing factors is the reduction of disturbing forces and moments that violate the programmed motion of the step in the pitch and yaw planes. Mass asymmetry and the angle of mismatch of the line of action of the thrust vector of its engine and the longitudinal axis of magnitude are constant. Therefore, a decrease in perturbing forces and moments is accompanied by a decrease in the amount of energy (fuel) spent on processing (zeroing) perturbations of the parameters of the perturbed motion of the stage. It is shown that if the thrust of a space-stage engine is 8000 kgf, the engine operating time (flight time of the stage) is 500 sec, the specific engine thrust is 330 sec, the mass asymmetry is 0.05 m, the angle of mismatch is 0.25 degrees, then fuel economy can reach 200 kgf. The studies were performed using mathematical modeling methods.

Diagnostics of the ice on the strike protection wire

The relevance of the research problem is chose of effective technology of strike protection wire monitoring in span with use of technical system of analysis of technical condition of strike protection wire of 110 kV voltage power line for complex assessment of the impact of both external climatic factors from wind and ice loads and the magnitude of the thermal elongation of the strike protection wire with influence of current during de-icing process. Analysis of the strike protection wire mode and their limiting values of mechanical strength allow evaluation of the effectiveness of events of prevent of accidents and reduce the undersupply of electricity to the end consumers. Visualization of the operative parameters of the strike protection wire in the span of the overhead power line will allow reduce the time to make decisions on the prevention of accidents of lines. Algorithm of monitoring of operative parameters of wires of overhead power lines base on information of longitudinal and transverse angles received from sensors installed directly on the strike protection wire.

Practical Implementation of Monitoring and Ice Melting on 110 – 120 kV Overhead Transmission Lines Based on the Dip Angle of the Wire

The problem studied here is important because of the need for an efficient technology for monitoring the state of the wire in a span based on combined software and hardware for analyzing the technical state of the wires in 110 kV overhead electrical transmission lines in order to obtain a comprehensive estimate of the effect of external climatic factors owing to wind and ice loading, as well as the amount of thermal elongation of the wires owing to the effect of current flow. An analysis of the instantaneous state of the wires and their limiting mechanical strength makes it possible to evaluate the effectiveness of measures for preventing accidents and lessening the undersupply of electrical power to final consumers. Visualizing the instantaneous parameters of the wire in a span of an overhead electrical transmission line will make it possible to reduce the time needed to undertake steps to prevent emergencies. The algorithm for monitoring the state of wires in overhead lines is based on information about the existing values of the longitudinal and transverse angles obtained with sensors that are installed directly on the wire in an electrical transmission line.

Impact of regenerative braking torque blend-out characteristics on electrified heavy road vehicle braking performance

Electric and hybrid vehicles use a co-operative brake system that consists of regenerative brake and friction brake with different dynamic characteristics to obtain adequate deceleration during braking. Hence, the mechanism of braking blend-out (that is the mechanism of switching off regenerative braking) may affect the vehicle braking performance. This work focusses on the development of various co-operative braking strategies (series and parallel) for electrified heavy road vehicles by considering instantaneous braking blend-out and ramp down braking blend-out characteristics. The developed co-operative braking strategies were evaluated in a Hardware-in-Loop experimental setup equipped with TruckMaker® software. The results showed that instantaneous braking blend-out has more impact on vehicle braking performance in terms of momentary magnitude change in the longitudinal deceleration, pitch angle and suspension deflection for a laden vehicle compared with an unladen vehicle on both dry and icy road surfaces. Ramp down braking blend-out reduced these momentary magnitude changes and thereby improved vehicle’s braking performance in terms of stopping distance and ride comfort. The results of this study indicate that ramp down braking blend-out is expected to improve the vehicle dynamic performance during active braking control due to the smooth transition between friction braking torque and regenerative braking torque.

Multi wavelength optical broad band photometric properties of a representative sample of geostationary satellites

We present the results of multi-wavelength optical observations, using B, V, R and I band filters, of a sample of 61 active geostationary communications satellites, on 2015 July 9–11. These observations were done outside the glinting season, with a longitudinal solar angle smaller than 6° and a latitudinal solar phase angle of ~16.5°. This approach enabled us to determine the distribution of quiescent magnitudes and colors of these targets during a period of the night when they are expected to be the brightest. We present the distribution of magnitudes and colors of the sample. We find that the colors of these satellites are in general redder than the Solar spectrum, with a wide distribution of values (0.62<B-V<1.49,1.00<B-R<2.28,1.31<B-I<3.07,0.34<V-R<0.90,0.63<V-I<1.69,0.27<R-I<0.79). Satellites from different manufacturers are found to cluster around specific colors in color-color plots, indicating that this information can be used to identify different satellites and resolve cross tagging issues. We also investigate whether the colors of satellites change with time and find that in most cases there is no significant change to these properties as the satellites age.

Investigating Long-term Synaptic Plasticity in Interlamellar Hippocampus CA1 by Electrophysiological Field Recording.

The study of synaptic plasticity in the hippocampus has focused on the use of the CA3-CA1 lamellar network. Less attention has been given to the longitudinal interlamellar CA1-CA1 network. Recently however, an associational connection between CA1-CA1 pyramidal neurons has been shown. Therefore, there is the need to investigate whether the longitudinal interlamellar CA1-CA1 network of the hippocampus supports synaptic plasticity. We designed a protocol to investigate the presence or absence of long-term synaptic plasticity in the interlamellar hippocampal CA1 network using electrophysiological field recordings both in vivo and in vitro. For in vivo extracellular field recordings, the recording and stimulation electrodes were placed in a septal-temporal axis of the dorsal hippocampus at a longitudinal angle, to evoke field excitatory postsynaptic potentials. For in vitro extracellular field recordings, hippocampal longitudinal slices were cut parallel to the septal-temporal plane. Recording and stimulation electrodes were placed in the stratum oriens (S.O) and the stratum radiatum (S.R) of the hippocampus along the longitudinal axis. This enabled us to investigate the directional and layer specificity of evoked excitatory postsynaptic potentials. Already established protocols were used to induce long-term potentiation (LTP) and long-term depression (LTD) both in vivo and in vitro. Our results demonstrated that the longitudinal interlamellar CA1 network supports N-methyl-D-aspartate (NMDA) receptor-dependent long-term potentiation (LTP) with no directional or layer specificity. The interlamellar network, however, in contrast to the transverse lamellar network, did not present with any significant long-term depression (LTD).

Numerical Simulation of Longitudinal Motion of High Speed Craft in Calm Water

In order to accurately estimate the hydrodynamic performance of high-speed crafts sailing in calm water, a numerical method based on CFD technology was established in this paper. The method included techniques such as cutting body mesh, overlapping mesh, two-phase flow, VOF model, and 6-DOF motion model. The numerical simulation of the craft’s heave and pitch coupling motion in hydrostatic water was carried out. The variation of the speed of the high speed craft with the change of the longitudinal angle and the center of gravity during the motion was analyzed. To prove feasibility and accuracy of numerical simulation method for hydrodynamic performance of longitudinal motion of high-speed crafts, the calculated results were compared with the experimental values of the ship model.

Investigating the influence of longitudinal tilt angles on the performance of small scale linear Fresnel reflectors for urban applications

The potential use of the small scale linear Fresnel reflectors in building applications can help European Union countries meet their sustainable development goals. The sizing of a small scale linear Fresnel reflector directly influences its primary cost as well as the annual energy output and, hence, its financial attractiveness. In addition, the area required for its installation is a critical parameter in most of the urban applications. This paper presents the analysis of the effects of the longitudinal inclination of the rows of mirrors and/or the absorber tube on the performance of small scale linear Fresnel reflectors. The effect of three parameters (i.e. energy absorbed by the absorber tube, energy area ratio, and primary cost) is evaluated for five cities in European Union. Different combinations of longitudinal tilt angles are analyzed and compared with the typical configuration of a large scale linear Fresnel reflector. Numerical simulations were carried out using a MATLAB code to calculate the energy absorbed by the absorber tube, the energy area ratio, and the primary cost. The comparison of the configurations provided insight into how latitude impacts on the results. It will be demonstrated that the energy absorbed by the absorber tube increase strongly with longitudinal tilt angles, and the primary cost increases weakly with longitudinal tilt angles, while the energy-to-area ratio decreases.

Formability behavior of Al/steel MIG arc brazed-fusion welded joint

5052 Al alloy plate was successfully lap-joined to galvanized steel plate by pulsed metal inert gas (MIG) arc welding with Al-Si filler wire. Formability properties of the Al/steel brazed-fusion welded joints with different welding parameters were characterized and investigated by bending and cupping tests. Sound weld appearance was obtained for all the fusion welded-brazed joint of aluminum alloy to steel in experiments, the average mechanical resistance of the joints reached up to 80% or so of that of the Al alloy base metal. The largest longitudinal face bending angle was 108°. There was an evident negative relationship between the welding heat input and the joint bending property. The formation of Fe2Al5Zn0.4 of intermetallic compounds (IMCs) at the brazed interface was an important influencing factor on the bending property of the joints. Based on the IMCs layer morphology, the fracture modes in bending tests were analyzed by three different paths of crack propagation owing to different welding heat inputs. During the cupping tests, surface crack initiation occurred in the heat-affected zone of the Al alloy side at welding heat input of 592 J/cm and the bulging drawing property was equivalent to that of the Al alloy base metal. The studies indicated the possibility and feasibility of manufacturing TWBs by the MIG brazed-fusion welding of Al alloy to steel.

Influencia de productos de la hidrólisis en el desempeño de un vehículo que opera con gasolina y gas natural en la altura

Introducción: En la actualidad existe un gran interés en la reducción en el uso de combustibles fósiles por la variación de los precios y los fuertes controles normativos, por lo cual se buscan métodos para disminuir el consumo de combustible en los motores de combustión interna, tales como el suministro de productos de la hidrólisis del agua en la admisión del motor.&#x0D; Objetivo: El objetivo del este trabajo es presentar los resultados de una metodología experimental aplicada para estimar el desempeño mecánico y ambiental de un vehículo alimentado con gasolina y gas natural, específicamente cuando al motor se le suministran productos resultantes de la hidrólisis del agua.&#x0D; Metodología: Para el suministro de dichos productos al vehículo se le instalo un dispositivo hidrólisis externo, y el vehículo fue instrumentado con una quinta rueda, sensores de temperatura y velocidad de revoluciones del motor, para realizar pruebas de aceleración en una carretera plana y una carretera con pendiente longitudinal. Adicionalmente, se realizaron pruebas de torque y potencia con dinamómetro de chasis y pruebas de emisiones contaminantes y de consumo de combustible. Las pruebas fueron realizadas en las afueras de la ciudad de Bogotá DC - Colombia, ubicada a 2650 m sobre el nivel del mar.&#x0D; Resultados: Los resultados muestran que los productos de la hidrólisis no mejoran el desempeño mecánico del vehículo, ya que aumentan el tiempo para llegada a las velocidades definidas en las pruebas de aceleración hasta en un 18% en el motor con gasolina y 7% en el motor con gas natural, mientras que el torque y la potencia del motor se incrementa alrededor del 1%. Por otro lado, los resultados de las pruebas de emisiones contaminantes indican que el consumo de combustible se reduce aproximadamente en un 7%.&#x0D; Conclusiones: Los resultados indican que el desempeño del vehículo no mejora, aunque el consumo de combustible disminuye, el desempeño ambiental no disminuye.

IMU-Based Automated Vehicle Slip Angle and Attitude Estimation Aided by Vehicle Dynamics.

The slip angle and attitude are vital for automated driving. In this paper, a systematic inertial measurement unit (IMU)-based vehicle slip angle and attitude estimation method aided by vehicle dynamics is proposed. This method can estimate the slip angle and attitude simultaneously and autonomously. With accurate attitude, the slip angle can be estimated precisely even though the vehicle dynamic model (VDM)-based velocity estimator diverges for a short time. First, the longitudinal velocity, pitch angle, lateral velocity, and roll angle were estimated by two estimators based on VDM considering the lever arm between the IMU and rotation center. When this information was in high fidelity, it was applied to aid the IMU-based slip angle and attitude estimators to eliminate the accumulated error correctly. Since there is a time delay in detecting the abnormal estimation results from VDM-based estimators during critical steering, a novel delay estimation and prediction structure was proposed to avoid the outlier feedback from vehicle dynamics estimators for the IMU-based slip angle and attitude estimators. Finally, the proposed estimation method was validated under large lateral excitation experimental tests including double lane change (DLC) and slalom maneuvers.

Effects of an inclined magnetic field on the unsteady squeezing flow between parallel plates with suction/injection

Abstract The problem of an unsteady squeezing flow of fluid between two parallel plates under the influence of an inclined magnetic field is analyzed. The longitudinal inclination angle of the applied magnetic field varies from 0 to 90 degrees. Viscous dissipation, Joule heating and the stretching velocity of the lower plate with suction or injection are also taken into account. The transformed nonlinear governing equations are solved numerically by a fourth-order Runge-Kutta scheme coupled with the shooting method. Impacts of the squeeze number, the magnetic parameter, the magnetic inclination angle, the lower-plate stretching parameter, the lower-plate suction/injection parameter and Eckert number on the velocity and temperature are pointed out, respectively. It is found that the inclination angle of the applied magnetic field also plays an important role in the velocity and heat transfer in squeezing flows. The influence of changing the magnetic field strength on the velocity and temperature can also be approximately achieved by adjusting the inclination angle of the applied magnetic field.

Sustainability of Individual EndoAnchor Implants in Therapeutic Use to Treat Type Ia Endoleak After Endovascular Aneurysm Repair

Purpose: To investigate changes in penetration depths and angles of EndoAnchor implants with initially good penetration after therapeutic use in endovascular aneurysm repair. Materials and Methods: Patients were selected from the Aneurysm Treatment Using the Heli-FX Aortic Securement System Global Registry (ANCHOR; ClinicalTrials.gov identifier NCT01534819). Inclusion criteria were (1) EndoAnchor implantation to treat intraoperative or late type Ia endoleak and (2) at least 2 postoperative computed tomography angiography (CTA) scans. Exclusion criteria were the use of adjunct procedures. Based on these criteria, 54 patients (44 men) with 360 EndoAnchor implants were eligible for this analysis. Penetration depth of each EndoAnchor implant into the aortic wall was judged as (1) good (≥2-mm penetration), (2) borderline (<2 mm or when there was a gap between the endograft and the aortic wall), or (3) no penetration. The penetration depth and longitudinal angles of EndoAnchors with good penetration were investigated on the last available postprocedure CTA scan. Endoleaks were also analyzed. Results: EndoAnchor penetration on the first postprocedure CTA scan was good in 187 (51.9%), borderline in 69 (19.2%), and missing in 104 (28.9%). On the last CTA scan, 182 (97.4%) of the 187 initially well-positioned EndoAnchors remained good. Five (2.6%) EndoAnchors in 4 patients changed configuration over time (4 became borderline and 1 became nonpenetrating), all without any clinical sequelae. The median orthogonal angles of the EndoAnchor implants with good penetration on the first and last CTA scans were 92° [interquartile range (IQR) 85, 98] and 90° (IQR 84, 97), respectively (p=0.822); for longitudinal angles, medians of 85° (IQR 71, 96) and 84° (IQR 70, 96) were found (p=0.043). Of the 18 (33%) patients who had a type Ia endoleak on the first postprocedure CTA, 6 resolved over time. Median follow-up was 13 months, during which no new type Ia endoleak was found. Conclusion: Despite the small number of EndoAnchors analyzed, this study showed that the sustainability of EndoAnchor implants with initially good penetration is satisfactory at 1-year follow-up. The vast majority of EndoAnchor implants with good penetration initially remained in good position; <3% of implants became borderline or nonpenetrating, without any clinical consequence.

Study on improvement of LuGre dynamical model and its application in vehicle handling dynamics

The accurate description of contact characteristics between tire and road surface may significantly affect the vehicle motion simulation and control analysis. Based on the LuGre tire model, the pressure distribution function of loading is modified as a non-uniform distribution pattern through new method of recursion formula. The mathematical expression of modified LuGre tire model is achieved through introducing the Bouc-Wen model to reflect tire hysteresis behavior, which takes into consideration the process of dynamic effect of tire vertical loading and tire footprint length. The effectiveness of model is verified through comparison with classic magic formula (MF) and LuGre tire model. Furthermore, the stability of solution for the modified LuGre tire model in the prediction of tire force and alignment torque is demonstrated in frequency domain. Finally, a nonlinear four-DOF vehicle handling dynamics model is built. The front wheel steering angle and the rotational angular velocities of the six tire from a calibrated virtual vehicle is entered into the vehicle model system with modified LuGre tire model as input data. The responses of longitudinal velocity, lateral velocity, yaw rate and roll angle are obtained under two kinds of limit conditions. The comparison results demonstrate the correctness and effectiveness of the built model, which further prove that the modified LuGre tire model is applicable for handling performance analysis of vehicle system.

Numerical investigation and optimization of an experimentally analyzed solar CPC

In this study a compound parabolic collector (CPC) taken from literature was investigated optically and thermally through simulation. The collector was tested at different transversal and the longitudinal incident angles and the results showed us a total agreement between the present and the previous study where TracePro software was used. In addition, a new optical efficiency relationship was proposed and it was found that diverges significantly from the commonly used relationship as the reflector's shape losses and/or the absorber's diameter increase. Also, the CFD analysis results were validated from the previous study experimental data (4.2% mean divergence in thermal efficiency), something that reveals how sufficiently the real problem has been approached. Finally, an optimization process was followed in order to improve the collector's optical performance, while the novel CPC resulted from the optimization was compared with the initial design for the typical conditions of the 11th of June in Athens from 08:00 to 16:00, in order to examine the effect of different solar irradiation intensities in the comparison process. It was revealed that the novel design exceeds the initial one in all the examined hours. The design and the simulation of the collector were conducted via Solidworks Flow Simulation software.

Thermo-optic control of the longitudinal radiation angle in a silicon-based optical phased array.

We demonstrate longitudinal beam-steering with a 1×16 silicon optical phased array (OPA) using a monochromatic light source and thermo-optic control of the refractive index in the grating radiator region. The refractive index is controlled by forming a series of n-i-n heaters, placing i-regions in each radiator of the OPA. When the biased voltage in the heaters is increased, the refractive index of the radiator region is increased by the thermo-optic effect, and the longitudinal radiation angle is changed according to the Bragg condition. The transversal beam-steering is accomplished by phase control with the phase shifters, which are devised with a p-i-n diode using the electro-optic effect. With these electro-optic p-i-n phase shifters and n-i-n thermo-optic radiators, we achieve a relatively wide 2D beam-steering in a range of 10.0°/45.4° in the longitudinal/transversal directions with a 1.55μm light source. The tuning efficiency is 0.016°/mW in the longitudinal beam-steering.

Shear capacity of reinforced concrete beams strengthened with web side bonded CFRP sheets

The shear capacity of reinforced concrete beams strengthened with web side bonded carbon fiber-reinforced polymer (CFRP) sheets was measured experimentally. Nine reinforced concrete beams without stirrups; three control beams and six beams strengthened with minimal application of web side bonded CFRP sheets, were tested. The test variables were ratio of longitudinal reinforcement (1%, 1.4%, and 2.4%) and angle of application of CFRP sheets (450 and 900). The test results show that reinforced concrete beams strengthened with web side bonded CFRP sheets have higher shear capacity compared to the control beams. Shear capacity of strengthened beams with 450 angle of application of CFRP sheets is similar to that of beams strengthened with 900 angles. Beams with 1% of longitudinal reinforcement ratio failed in flexural mode indicated by concrete crushing in compression zone while beams with higher longitudinal reinforcement ratio (1.4% and 2.4%) failed in brittle mode as indicated by delamination of the concrete cover.

Study Of Interior Temperature Distribution And Implementation Of Smart Materials In The Truck Cabin During Summer Conditions

Abstract Temperature in the inner part of the automotive vehicle compartment is very important to provide affluent state to the passengers. Temperature in the interiorpart of the chamberwill be improve, when the automobile is parked right underneaththe sunlight. The radiation episode to the surface varies from second to secondbased upon its geographical position (latitude and longitude of the place), orientation, season, time of the day and atmospheric conditions. Inadvertence of clouds, the daily average illumination for the Earth is nearly230 W/m2 .Major 13 hottest cities in these four zones were considered to study interior temperature and heat contents in the truck cabin. The data of temperatures in these cities at the interval of 11 am to 2 pm were collected for month of March to Mid of June for 2010 to 2017, and average max temperature and Relative Humidity (RH) were identified for these years .These values are further used for the calculations of Zenith (altitude) angle, azimuth (longitudinal) angle, and Sky temperature. In the mathematical modelling, CFD analysis, and heat transfer mechanism – equations for conduction, convention and radiation through vehicle body and window glasses is important to determine interior truck cabin temperature, distribution and heat, then changing the material of the truck depending upon the CFD analysis done. Materials such as thermo electric materials, phase change materials and solar cells are implemented with electrical integration system. This research proposes a new perspective that by implementing these materials reduce of cabin internal temperature to a larger extent can be done and increase the fuel efficiency during summer.All in all, it can be terminated that by switch of the materials is the best method in reducing the interior temperature inside the truck cabin

Increasing the smoothness of the course of the forage harvester by optimizing the mass-dimensional and inertial parameters of its body

A scientific and methodological rationale and practical recommendations for stabilizing the movement of forage harvesters are proposed. The calculation of the optimal weight and size and inertial parameters of the body, as well as the elastic properties of tires as the main element of the suspension system of the combine was theoretically justified. Using the developed methodology on the example of a prototype harvester, the possibility of calculating the optimal tire stiffness and the mass of additional counterweights installed at the machine is shown to ensure equality of the natural frequencies of the front and rear axles of the wheels on the elastic tire. Taking into account the mathematical and simulation model of the combine, which was developed by authors, its motion on a dirt road and asphalt highway with different speeds was modeled. To evaluate the effectiveness of the proposed method for improving ride smoothness, a comparison was made of the peak and root-mean-square values of the longitudinal angle of inclination of the body, as well as the levels of vertical vibration acceleration in the cab on the floor under the seat of the combine operator in its basic version and a modified version due to the use of counterweights of a given mass and with optimized tire stiffness. With the help of simulation modeling, an octave analysis of the vibration load of the workplace was performed. It is shown that in the main driving modes, optimization of the weight, size and inertial parameters of the body, as well as the elastic properties of the combine tires, improves the comfort of the operator’s workplace, especially in the most dangerous frequency range for humans. There are determined the modes of movement, which allow to achieve the best effect. The stabilization process is described. The conclusions for further research are presented.