Design of Autonomous Quadcopter Using Orientation Sensor with Variations in Load Fulcrum Point

Lontar Komputer Jurnal Ilmiah Teknologi Informasi ◽

10.24843/lkjiti.2019.v10.i02.p03 ◽

2019 ◽

pp. 84

Author(s):

Ratna Aisuwarya ◽

Fitra Marta Yonas ◽

Dodon Yendri

Keyword(s):

Steady State ◽

Aerial Photography ◽

Maximum Load ◽

Additional Load ◽

Orientation Sensor ◽

Specific Implementation ◽

Gyroscope Sensor ◽

Load Carrier

In designing the quadcopter, the main focus is stability and balance. Thus, in the more specific implementation, for example for aerial photography, a quadcopter can also be used as a load carrier. To be able to balance the quadcopter equipped with an orientation sensor on the controller, the orientation sensor includes a gyroscope sensor, accelerometer, and magnetometer. For this reason, it is necessary to have an autonomous stabilizer mechanism that can make the quadcopter stay in a stable and balanced condition even with the additional load. Furthermore, in this research, we will discuss how to determine the PID set points for quadcopter balance that can be tested on loads with different fulcrums. The test is limited to the condition of the quadcopter being hovered for pitch and roll angles. Based on the testing results, it can be concluded that there is a stability response in the Quadcopter. It can be seen from the RMS value obtained that it is by the steady-state tolerance of 2% -5% of the setpoint. Then, the Quadcopter can carry the maximum load with different fulcrums; 950g for fulcrum in the middle of the quadcopter, 580g for the load is placed 6 cm from the middle of the quadcopter, and 310g if the load is placed on one motor.

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Role of Biodiesel-Diesel Blends in Alteration of Particulate Matter Emanated by Diesel Engine

Pakistan Journal of Scientific & Industrial Research Series A: Physical Sciences ◽

10.52763/pjsir.phys.sci.58.1.2015.17.25 ◽

2015 ◽

Vol 58 (1) ◽

pp. 17-25

Author(s):

Asad Naeem Shah ◽

Ge Yun- Shan ◽

Tan Jian- Wei ◽

Ejaz Mahmood Shahid

Keyword(s):

Particulate Matter ◽

Steady State ◽

Test Bench ◽

Direct Injection ◽

Maximum Load ◽

Compression Ignition ◽

Adsorption Phenomenon ◽

State Cycle ◽

Blended Fuels

The current study is focused on the investigation of the role of biodiesel in the alteration of particulate matter (PM) composition emitted from a direct injection-compression ignition. Two important blends of biodiesel with commercial diesel known as B20 (20% biodiesel and 80% diesel by volume) and B50 were used for the comparative analysis of their pollutants with those of 100% or traditional diesel (D). The experiments were performed under the auspices of the Chinese 8-mode steady- state cycle on a test bench by coupling the engine with an AC electrical dynamometer. As per experimental results, over-50 nm aerosols were abated by 8.7-47% and 6-51% with B20 and B50, respectively, on account of lofty nitrogen dioxide to nitrogen oxides (NO2/NO´) ratios. In case of B50, sub-50 nm aerosols and sulphates were higher at maximum load modes of the test, owing to adsorption phenomenon of inorganic nuclei leading to heterogeneous nucleation. Moreover, trace metal emissions (TME) were substantially reduced reflecting the reduction rates of 42-57% and 64-80% with B20 and B50, respectively, relative to baseline measurements taken with diesel. In addition to this, individual elements such as Ca and Fe were greatly minimised, while Na was enhanced with biodiesel blended fuels.

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Analysis and comparison of steady-state performance characteristics of two-axial groove and multilobe hydrodynamic bearings lubricated with non-Newtonian fluids

Proceedings of the Institution of Mechanical Engineers Part J Journal of Engineering Tribology ◽

10.1177/1350650118758087 ◽

2018 ◽

Vol 232 (12) ◽

pp. 1581-1596 ◽

Cited By ~ 5

Author(s):

Bhrigu Jyoti Das ◽

Lintu Roy

Keyword(s):

Steady State ◽

High Speed ◽

Journal Bearing ◽

Maximum Flow ◽

Maximum Load ◽

Performance Characteristics ◽

Flow Coefficient ◽

Rotating Speed ◽

The Stability ◽

Steady State Performance

Rotating machines are one of the most important and widely used machineries in the modern engineering world. They are also the required to run at high rotating speed. The plain journal bearing is mostly replaced by some other bearing, as it does not suit the stability requirement of high-speed machines and precision machine tools. In order to improve the stability of a circular bearing, many researchers tried to change its geometrical configuration. In view of this, an attempt has been made in the present work to study the performance characteristics of four different bearing configurations using non-Newtonian lubricant and comparison of the results has been made with plain journal bearing. To calculate the steady-state performance characteristics, nondimensional form of the Reynolds equation using non-Newtonian lubricant has been written and solved for the steady-state nondimensional pressure distribution in a finite grid using finite difference method with successive over-relaxation technique satisfying appropriate boundary condition. From the study, it can be concluded that three-lobe bearing have maximum load-carrying capacity and minimum friction variable, whereas two-lobe bearing have maximum flow coefficient.

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Resistance Against Cavitation Erosion of 14 Chromium Steels

Journal of Lubrication Technology ◽

10.1115/1.3451365 ◽

1970 ◽

Vol 92 (2) ◽

pp. 220-226 ◽

Cited By ~ 9

Author(s):

J. W. Tichler ◽

J. B. van den Elsen ◽

A. W. J. de Gee

Keyword(s):

Steady State ◽

Cavitation Erosion ◽

Size Structure ◽

Structural Parameters ◽

Maximum Load ◽

Strength Properties ◽

Volume Loss ◽

Chromium Steels ◽

Composition And Structure ◽

Final Steady State

For 14 chromium steels of different composition and structure, cavitation-erosion damage has been studied and interpreted in terms of structure and strength properties. The use of chambered cylindrical specimens ensured a uniform attack from the very beginning of the erosion process and, thus, highly reproducible wear values. As could be expected on the basis of existing evidence, the duration of the incubation period is a function of the initial condition of the surface, as determined by the finishing process. The reciprocal rate of volume loss, occurring during the first steady-state period (which is characterized by a uniform attack of the surface, without formation of deep craters) (Rc), turned out to be a linear function of the “true” tensile strength, measured at maximum load. It does not depend on grain size, structure and elongation properties of the material. On the other hand, the tendency toward the formation of craters in the surface and the ratio Rc/R∼, in which R∼ is the reciprocal rate of volume loss, during the second, and final, steady-state period, are shown to be exclusively determined by structural parameters.

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How should the lift and drag forces be calculated from 2-D airfoil data for dihedral or coned wind turbine blades?

10.5194/wes-2021-163 ◽

2022 ◽

Author(s):

Ang Li ◽

Mac Gaunaa ◽

Georg Raimund Pirrung ◽

Alexander Meyer Forsting ◽

Sergio González Horcas

Keyword(s):

Steady State ◽

Wind Turbine ◽

Flow Direction ◽

Aerodynamic Forces ◽

Drag Forces ◽

Thin Airfoil ◽

Lift And Drag ◽

Specific Implementation ◽

Lifting Line ◽

Blade Element

Abstract. In the present work, a consistent method for calculating the lift and drag forces from the 2-D airfoil data for the dihedral or coned horizontal-axis wind turbines when using generalized lifting-line methods is described. The generalized lifting-line methods include, for example, lifting-line (LL), actuator line (AL), blade element momentum (BEM) and blade element vortex cylinder (BEVC) methods. A consistent interpretation of classic unsteady 2-D thin airfoil theory results for use in a generally moving frame of reference within a linearly varying onset velocity field reveals that it is necessary to use not only the relative flow magnitude and direction at one point along the chord line (for instance three-quarter-chord), but also the gradient of the flow direction in the chordwise direction (or, equivalently, the flow direction at the quarter-chord) to correctly determine the magnitude and direction of the resulting 2-D aerodynamic forces and moment. However, this aspect is generally overlooked and most implementations in generalized lifting-line methods use only the flow information at one calculation point per section for simplicity. This simplification will not change the performance prediction of planar rotors, but will cause an error when applied to non-planar rotors. The present work proposes a generalized method to correct the error introduced by this simplified single-point calculation method. In this work this effect is investigated using the special case, where the wind turbine blade has only dihedral and no sweep, operating at steady-state conditions with uniform inflow applied perpendicular to the rotor plane. We investigate the impact of the effect by comparing the predictions of the steady-state performance of non-planar rotors from the consistent approach with the simplified one-point approach of the LL method. The results are verified using blade geometry resolving Reynolds-averaged Navier-Stokes (RANS) simulations. The numerical investigations confirmed that the correction derived from thin airfoil theory is needed for the calculations to correctly determine the magnitude and direction of the sectional aerodynamic forces for non-planar rotors. The aerodynamic loads of upwind and downwind coned blades that are calculated using the LL method, the BEM method, the BEVC method and the AL method are compared for the simplified and the full method. Results using the full method, including different specific implementation schemes, are shown to agree significantly better with fully-resolved RANS than the often used simplified one-point approaches.

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Studies on Water in the Hydration Chamber of a Modified Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069715 ◽

1970 ◽

Vol 28 ◽

pp. 544-545

Author(s):

R. C. Moretz ◽

G. G. Hausner ◽

D. F. Parsons

Keyword(s):

Thin Film ◽

Thin Films ◽

Electron Microscope ◽

Steady State ◽

Room Temperature ◽

Small Mass ◽

Equilibrium Pressure ◽

Biological Objects ◽

Mechanical Pump ◽

Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

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Continuous hydrogenolysis of acetal-stabilized lignin in flow

Green Chemistry ◽

10.1039/d0gc02928a ◽

2021 ◽

Author(s):

Wu Lan ◽

Yuan Peng Du ◽

Songlan Sun ◽

Jean Behaghel de Bueren ◽

Florent Héroguel ◽

...

Keyword(s):

Steady State ◽

Challenges And Opportunities

We performed a steady state high-yielding depolymerization of soluble acetal-stabilized lignin in flow, which offered a window into challenges and opportunities that will be faced when continuously processing this feedstock.

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