The Influence of Spraying Angle on Robotic Trajectory Planning

2013 ◽  
Vol 442 ◽  
pp. 225-228
Author(s):  
Yan Chen ◽  
Wen Zhuo Chen ◽  
Ken Chen ◽  
Jun Yi Shao ◽  
Wei Ming Zhang
Keyword(s):  
Film Thickness ◽  
Trajectory Planning ◽  
Tracking Error ◽  
Roll Angle ◽  
Spray Angle ◽  
Functional Relations ◽  
Coating Uniformity ◽  
Yaw Angle ◽  
Average Film Thickness ◽  
Spray Gun

The influence of roll angle on coating uniformity is analyzed by establishing the formula between the average film thickness and it. The functional relations of coating uniformity to yaw angle and roll angle are obtained by measuring the average film thickness under the diferrent angles. The minor changes of spray angle have little influence on coating uniformity, and the tracking error of robotic spray gun is very small, therefore it can be ignored when studying robotic trajectory planning. The alteration of spraying angle, spraying distance and moving speed of spray gun can lead to the change of coating thickness, so optimized combination of them can improve coating uniformity.

Experimental comparison of the spray atomization of heavy and light fuel oil at different temperatures and pressures for pressure-swirl injector

2021 ◽  
pp. 095765092199437
Author(s):  
Elyas Rostami ◽  
Hossein Mahdavy Moghaddam
Keyword(s):  
Film Thickness ◽  
Liquid Film ◽  
Diesel Fuel ◽  
Temperature Increase ◽  
Liquid Film Thickness ◽  
Fuel Oil ◽  
Spray Angle ◽  
Breakup Length ◽  
Fuel Atomization ◽  
Mean Diameter

In this study, the atomization of heavy fuel oil (Mazut) and diesel fuel at different pressures is compared experimentally. Also, the effects of temperature on the Mazut fuel atomization are investigated experimentally. Mass flow rate, discharge coefficient, wavelength, liquid film thickness, ligament diameter, spray angle, breakup length, and sature mean diameter are obtained for the Mazut and diesel fuel. Fuels spray images at different pressures and temperatures are recorded using the shadowgraphy method and analyzed by the image processing technique. Error analysis is performed for the experiments, and the percentage of uncertainty for each parameter is reported. The experimental results are compared with the theoretical results. Also, Curves are proposed and plotted to predict changes in the behavior of atomization parameters. Diesel fuel has less viscosity than Mazut fuel. Diesel fuel has shorter breakup length, wavelength, liquid film thickness, and sature mean diameter than Mazut fuel at the same pressure. Diesel fuel has a larger spray angle and a larger discharge coefficient than Mazut fuel at the same pressure. As the pressure and temperature increase, fuel atomization improves. The viscosity of Mazut fuel is decreased by temperature increase. As the fuel injection pressure and temperature increase, breakup length, wavelength, liquid film thickness, and sature mean diameter decrease; also, spray angle increases.

scholarly journals Trajectory optimization of UAV based on Hp-adaptive Radau pseudospectral method

2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Yi Cui ◽  
Xintong Fang ◽  
Gaoqi Liu ◽  
Bin Li
Keyword(s):  
Trajectory Planning ◽  
Trajectory Optimization ◽  
Optimization Problem ◽  
Tracking Error ◽  
Pseudospectral Method ◽  
Planning Problem ◽  
A Algorithm ◽  
Planning Scheme ◽  
Path Search ◽  
Simulation Results

<p style='text-indent:20px;'>Unmanned Aerial Vehicles (UAVs) have been extensively studied to complete the missions in recent years. The UAV trajectory planning is an important area. Different from the commonly used methods based on path search, which are difficult to consider the UAV state and dynamics constraints, so that the planned trajectory cannot be tracked completely. The UAV trajectory planning problem is considered as an optimization problem for research, considering the dynamics constraints of the UAV and the terrain obstacle constraints during flight. An hp-adaptive Radau pseudospectral method based UAV trajectory planning scheme is proposed by taking the UAV dynamics into account. Numerical experiments are carried out to show the effectiveness and superior of the proposed method. Simulation results show that the proposed method outperform the well-known RRT* and A* algorithm in terms of tracking error.</p>

Effect of Adding Stone Sludge as Sand Replacement on Fresh Properties of Mortar

2020 ◽  
Vol 984 ◽  
pp. 213-218
Author(s):  
Yong Xia ◽  
Jia Jian Chen ◽  
An Min Ma ◽  
Zi Hong Li
Keyword(s):  
Film Thickness ◽  
Packing Density ◽  
Fresh Properties ◽  
River Sand ◽  
Average Film Thickness ◽  
Density Results ◽  
Packing Densities

Shortage of river sand and disposal of stone sludge are the problem of the construction and stone product industries, respectively. Utilization of stone sludge in mortar is one of the feasible strategies to solve these two problems. To study the effects of addition of stone sludge on the performance of mortar, 20 mixes of stone sludge powder mortar with various water/cement ratios and various stone sludge powder contents were produced for flowability measurement. To further study the governing mechanism of flowability and the packing densities of the solid proportions of the 20 mortar mixes were measured. Based on the packing density results, the average film thickness (AFT) of the 20 mortar mixes were calculated for flowability indication. Results proved that addition of stone sludge powder as sand replacement would decrease the flowability. The flowability was mainly governed by the AFT.

scholarly journals Cone Algorithm of Spinning Vehicles under Dynamic Coning Environment

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Shuang-biao Zhang ◽  
Xing-cheng Li ◽  
Zhong Su
Keyword(s):  
Pitch Angle ◽  
Euler Angle ◽  
Roll Angle ◽  
Angle Error ◽  
Attitude Error ◽  
Spinning Process ◽  
Cone Algorithm ◽  
Definition Of ◽  
Yaw Angle ◽  
The Relationship

Due to the fact that attitude error of vehicles has an intense trend of divergence when vehicles undergo worsening coning environment, in this paper, the model of dynamic coning environment is derived firstly. Then, through investigation of the effect on Euler attitude algorithm for the equivalency of traditional attitude algorithm, it is found that attitude error is actually the roll angle error including drifting error and oscillating error, which is induced directly by dynamic coning environment and further affects the pitch angle and yaw angle through transferring. Based on definition of the cone frame and cone attitude, a cone algorithm is proposed by rotation relationship to calculate cone attitude, and the relationship between cone attitude and Euler attitude of spinning vehicle is established. Through numerical simulations with different conditions of dynamic coning environment, it is shown that the induced error of Euler attitude fluctuates by the variation of precession and nutation, especially by that of nutation, and the oscillating frequency of roll angle error is twice that of pitch angle error and yaw angle error. In addition, the rotation angle is more competent to describe the spinning process of vehicles under coning environment than Euler angle gamma, and the real pitch angle and yaw angle are calculated finally.

Roughness Amplitude Reduction Under Non-Newtonian EHL Conditions

2005 ◽  
Author(s):  
A. D. Chapkov ◽  
C. H. Venner ◽  
A. A. Lubrecht
Keyword(s):  
Film Thickness ◽  
Pressure Fluctuations ◽  
Elastohydrodynamic Lubrication ◽  
Operating Conditions ◽  
Quantitative Prediction ◽  
Point Contacts ◽  
Minimum Film Thickness ◽  
Roughness Amplitude ◽  
Average Film Thickness ◽  
Ehl Contact

The influence of surface roughness on the performance of bearings and gears operating under ElastoHydrodynamic Lubrication (EHL) conditions has become increasingly important over the last decade, as the average film thickness decreased due to various influences. Surface features can reduce the minimum film thickness and thus increase the wear. They can also increase the temperature and the pressure fluctuations, which directly affects the component life. In order to describe the roughness geometry inside an EHL contact, the amplitude reduction of harmonic waviness has been studied over the last ten years. This theory currently allows a quantitative prediction of the waviness amplitude and includes the influence of wavelength and contact operating conditions. However, the model assumes a Newtonian behaviour of the lubricant. The current paper makes a first contribution to the extension of the roughness amplitude reduction for EHL point contacts including non-Newtonian effects.

scholarly journals A Comprehensive Model to Predict Simplex Atomizer Performance

1999 ◽  
Vol 121 (2) ◽  
pp. 285-294 ◽  
Author(s):  
Y. Liao ◽  
A. T. Sakman ◽  
S. M. Jeng ◽  
M. A. Jog ◽  
M. A. Benjamin
Keyword(s):  
Stability Analysis ◽  
Film Thickness ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Density Ratio ◽  
Spray Angle ◽  
Small Scale ◽  
Finite Volume Scheme ◽  
Axial Component ◽  
Liquid Sheets

The pressure swirl atomizer, or simplex atomizer, is widely used in liquid fuel combustion devices in the aerospace and power generation industries. A computational, experimental, and theoretical study was conducted to predict its performance. The Arbitrary-Lagrangian-Eulerian method with a finite-volume scheme is employed in the CFD model. Internal flow characteristics of the simplex atomizer, as well as its performance parameters such as discharge coefficient, spray angle and film thickness, are predicted. A temporal linear stability analysis is performed for cylindrical liquid sheets under three-dimensional disturbances. The model incorporates the swirling velocity component, finite film thickness and radius that are essential features of conical liquid sheets emanating from simplex atomizers. It is observed that the relative velocity between the liquid and gas phases, density ratio and surface curvature enhance the interfacial aerodynamic instability. The combination of axial and swirling velocity components is more effective than only the axial component for disintegration of liquid sheet. For both large and small-scale fuel nozzles, mean droplet sizes are predicted based on the linear stability analysis and the proposed breakup model. The predictions agree well with experimental data at both large and small scale.

Film Thickness, Droplet Size Measurements and Correlations for Large Pressure-Swirl Atomizers

1998 ◽  
Author(s):  
M. A. Benjamin ◽  
A. Mansour ◽  
U. G. Samant ◽  
S. Jha ◽  
Y. Liao ◽  
...  
Keyword(s):  
Film Thickness ◽  
Droplet Size ◽  
Large Scale ◽  
Spray Angle ◽  
Orifice Diameter ◽  
Flow Number ◽  
Swirl Chamber ◽  
Large Pressure ◽  
Nozzle Geometries ◽  
Pressure Swirl

A parametric experimental study has been conducted to measure the discharge coefficient, the flow number, the film thickness, the spray angle, the velocity coefficient and droplet size of a large-scale simplex nozzle using ultrasonic and optical techniques. Seventeen nozzle geometries have been studied for three mass flow rates. The large-scale nozzle provides adequate resolution for measurements of film thickness, spray angle, and droplet size. The experimental data collected have been used to derive new and improved correlations for nozzle flow and breakup parameters. It is found that the atomizer constant (ratio of total inlet area to product of the swirl chamber and orifice diameter) is the primary parameter affecting the atomizer performance. As the atomizer constant increases, the discharge and velocity coefficients increase and the spray angle decreases.

A globally convergent tracking controller for the X4 flyer rotor craft for reference trajectories with positive thrust

Robotica ◽  
2004 ◽  
Vol 22 (4) ◽  
pp. 375-388 ◽  
Author(s):  
Brian J. Driessen ◽  
Alexandre L. Robin
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Tracking Error ◽  
Reference Trajectory ◽  
Two Phase ◽  
Globally Convergent ◽  
Tracking Controller ◽  
Control Objective ◽  
Yaw Angle ◽  
Angle Tracking

In this paper we present a globally convergent and ultimately exponentially convergent tracking controller for an X4 Flyer rotor craft. The desired or reference trajectory is restricted in one way: its scalar thrust must be uni signed and bounded away from zero. The proposed controller is a two phase one. Phase I converges the attitude (orientation) error and thrust error to zero globally and ultimately exponentially. Phase II is a position tracking and relative yaw angle tracking controller, which is not globally convergent by itself. By carefully postponing a switch from Phase I to Phase II, we are able to assure that Phase II will ultimately drive the position error and relative yaw angle error to zero exponentially. In problem-statement/theorem/proof format, we define the system, the control objective, the proposed controller, and a rigorous proof that the controller maintains boundedness of all closed loop signals and provides global convergence of the tracking error to zero and also ultimately exponential convergence of the tracking error to zero.

Dynamic Modeling and Simulation of a Yaw-Angle Quadruped Maneuvering With a Planar Robotic Tail

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
William Rone ◽  
Pinhas Ben-Tzvi
Keyword(s):  
Dynamic Modeling ◽  
Trajectory Planning ◽  
Frequency Modulation ◽  
Quadruped Robot ◽  
Contact Friction ◽  
Ground Contact ◽  
Cycle Frequency ◽  
Tail Structure ◽  
Yaw Angle ◽  
The Impact

This paper analyzes the impact a planar robotic tail can have on the yaw-angle maneuvering of a quadruped robot. Tail structures ranging from a one degree-of-freedom (1DOF) pendulum to a 6DOF serpentine robot are simulated, along with a quadruped model that accounts for ground contact friction. Tail trajectory generation using split-cycle frequency modulation is used to improve net quadruped rotation due to the tail's motion. Numerical results from the tail and quadruped models analyze the impact of trajectory factors and tail structure on the net quadruped rotation. Results emphasize the importance of both tangential and centripetal tail loading for tail trajectory planning and show the benefit of a multi-DOF tail.

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