A Rapid Planning Method for the Freeform Surface Spraying Based on CAD Model

2013 ◽  
Vol 442 ◽  
pp. 599-604
Author(s):  
Shuang Man Xu ◽  
Wei Jing Li

In order to solve the freeform surface spray planning problem in spray industrial, this article proposed a model of the spray gun and description of the spray procedure. Then, the article presents a rapid planning method based on CAD model of the workpiece. With this method, the spray trajectory is constructed by the path points normal vector and S-shaped path using CAD model. In ABB's RobotStudio simulation software, a spray experiment is carried out. The simulation results show that this method can effectively simplify the offline planning process and save processing time.

Author(s):  
Mayur V. Andulkar ◽  
Shital S. Chiddarwar

Purpose This paper aims to present a new offline robot programming approach for automated trajectory generation on free-form surfaces targeted toward spray painting application. Design/methodology/approach In this paper, an incremental trajectory generation approach is developed where new paint passes are generated based on paint deposited on the surface as a result of previous paint passes. The trajectory is generated on real surfaces where optimal velocity is calculated using genetic algorithm considering parameters such as surface model, spray gun model, paint distribution model and task constraints. Findings The developed approach was implemented on various surfaces for different paint distribution patterns, and the simulation results reveal that the approach is flexible and efficient to handle variety in part geometry and paint distribution. From experimental validation and analysis of results thus obtained, the developed approach is highly promising compared to the existing methods. Research limitations/implications The approach assumes that the computer-aided design (CAD) model of the surface is available and is limited to surjective surfaces in a structured environment where the spray gun characteristics and process parameters are known beforehand. Practical implications The problem of programming a robot manually is overcome by automatically generating a sub-optimal trajectory which can be easily transferred to an industrial robot for spray painting the surface. Originality/value This paper discusses a new approach for automated trajectory generation from CAD model. The experimental validation of the developed approach is successfully performed on a highly curved test surface, and obtained results are in agreement with the simulation results.


Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1342
Author(s):  
Van Chien Pham ◽  
Jae-Hyuk Choi ◽  
Beom-Seok Rho ◽  
Jun-Soo Kim ◽  
Kyunam Park ◽  
...  

This paper presents research on the combustion and emission characteristics of a four-stroke Natural gas–Diesel dual-fuel marine engine at full load. The AVL FIRE R2018a (AVL List GmbH, Graz, Austria) simulation software was used to conduct three-dimensional simulations of the combustion process and emission formations inside the engine cylinder in both diesel and dual-fuel mode to analyze the in-cylinder pressure, temperature, and emission characteristics. The simulation results were then compared and showed a good agreement with the measured values reported in the engine’s shop test technical data. The simulation results showed reductions in the in-cylinder pressure and temperature peaks by 1.7% and 6.75%, while NO, soot, CO, and CO2 emissions were reduced up to 96%, 96%, 86%, and 15.9%, respectively, in the dual-fuel mode in comparison with the diesel mode. The results also show better and more uniform combustion at the late stage of the combustions inside the cylinder when operating the engine in the dual-fuel mode. Analyzing the emission characteristics and the engine performance when the injection timing varies shows that, operating the engine in the dual-fuel mode with an injection timing of 12 crank angle degrees before the top dead center is the best solution to reduce emissions while keeping the optimal engine power.


2012 ◽  
Vol 433-440 ◽  
pp. 7287-7292
Author(s):  
You Hua Gao ◽  
Zeng Feng Lai ◽  
Xiao Ming Liu ◽  
Guo Wei Liu ◽  
Ye Wang

To analyze the transient response of transformer windings under very fast transient over-voltage (VFTO), multi-conductor transmission line (MTL) model based on the representation of transformer windings by its individual turns are established. Space discretization is needed for solving the time-domain telegraph equations of MTL. To calculate the voltage distributions along transformer windings, through combining the compact finite difference (CFD) theory and the backward differentiation formulas (BDF). Simulation software ATP is introduced, and the simulation results demonstrate that the proposed approach is feasible.


2013 ◽  
Vol 753-755 ◽  
pp. 1318-1323 ◽  
Author(s):  
Kwang Kyu Seo ◽  
Hong Kyu Kwon

In this research, Computer Aided Engineering (CAE) simulation was performed by using the simulation software (AnyCasting) in order to optimize casting design of an automobile part (Oil Pan_7G9E) which is well known and complicated to achieve a good casting layout. The simulation results were analyzed and compared carefully in order to apply them into the production die-casting mold. During the filling process, internal porosities caused by air entrap were predicted and reduced remarkably by the modification of the gate system and the configuration of overflow. With the solidification analysis, internal porosities caused by the solidification shrinkage were predicted and reduced by the modification of the gate system.


2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Yi Cui ◽  
Xintong Fang ◽  
Gaoqi Liu ◽  
Bin Li

<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>


Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6821
Author(s):  
Ju-Hwan Seol ◽  
Van Chien Pham ◽  
Won-Ju Lee

This paper presents research on the effects of the multiple injection strategies on the combustion and emission characteristics of a two-stroke heavy-duty marine engine at full load. The ANSYS FLUENT simulation software was used to conduct three-dimensional simulations of the combustion process and emission formations inside the engine cylinder in both single- and double-injection modes to analyze the in-cylinder pressure, temperature, and emission characteristics. The simulation results were then compared and showed good agreement with the measured values reported in the engine’s sea-trial technical reports. The simulation results showed reductions in the in-cylinder pressure and temperature peaks by 6.42% and 12.76%, while NO and soot emissions were reduced up to 24.16% and 68%, respectively, in the double-injection mode in comparison with the single-injection mode. However, the double-injection strategy increased the CO2 emission (7.58%) and ISFOC (23.55%) compared to the single-injection. These are negative effects of the double-injection strategy on the engine that the operators need to take into consideration. The results were in line with the literature reviews and would be good material for operators who want to reduce the engine exhaust gas emission in order to meet the stricter IMO emission regulations.


Author(s):  
Dhaul Fathoni ◽  
Johan Krisnanto Runtuk

PT.S is a metal pressing company that produces spare parts for the automotive industry. The increasing number of new companies, encouraging the company to make improvements continously, one of which is by reducing the processing time. The problem that occurs is the frequent occurrence of late pulling stocks in the finished product inventory area. One of them occurs in the Cap product (C1805-009) within a period of 6 months (October 2017 to March 2018) 16 times the stockout in the finished product inventory area. In addition, an increase in demand requires companies to do various ways, including adding four inspectors on each shift. This study aims to analyze the flow of production processes and waste of time with a simulation approach. Based on the simulation results using the Promodel software, it is known that the work station that is the cause of flow congestion is the inspection work station. Proposed improvements in simulation results also showed improvements, namely the reduction of processing time by 330.66% and the reduction in the number of operators by 50%. The simulation results can be considered by PT. S to improve the flow of the Cap product manufacturing process (C1805-009).


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Zeng-qiang Yang ◽  
Hong-mei Wang ◽  
De-quan Sun ◽  
Xian-jian Ma ◽  
Ming-bao Xu ◽  
...  

In order to study the occurrence mechanism of rock burst in L-shaped zone during a fully mechanized mining period, the No. 705 working face which is located in Baojishan Colliery is taken as a typical engineering background. By means of in situ investigation, theoretical analysis, numerical simulation, in situ tests, and relevant monitoring methods, the occurrence mechanism of rock burst and corresponding prevention technology are studied. The results show that a coal pillar with some confining pressure in the L-shaped zone is established by FLAC3D numerical simulation software, and the numerical simulation results indicate that the change in static load has a greater effect than dynamic load on coal pillar unstable failure; the static load plays a role in storing energy, and dynamic load plays a role in inducing rock burst; the bolt-mesh-cable support and high-pressure water jet unloading combined technology is put forward to prevent rock burst in roadways, and the numerical simulation results show that stress distribution of surrounding rock meets the model of strong-soft-strong (3S) structure, and the moment distribution is reasonable. In the follow-up mining, a limit value of coal fines is used to determine that this measure is a reasonable method to prevent rock burst. The study conclusions provide theoretical foundation and new guidance for preventing rock burst by synergistic effect technology in roadways.


2010 ◽  
Vol 40-41 ◽  
pp. 361-365
Author(s):  
Ya Qin Fan ◽  
Hao Fan ◽  
Chao Sun

This paper features of IPSec and MPLS technologies, proposes a suitable MPLS VPN security solutions. The program to solve the VPN using MPLS backbone network in the public transport there is a second layer of information can not automatically encrypt, or connect easily made because of errors due to the interruption of information disclosure and other issues. To verify the proposed security program, the actual MPLS VPN can be simplified, abstracestablishing a simulation system MPLS VPN, and using OPNET simulation software simulation, simulation results of VPN officers practical reference value.


2021 ◽  
Vol 64 (2) ◽  
pp. 365-376
Author(s):  
Da-Vin Ahn ◽  
In-Kyung Shin ◽  
Jooseon Oh ◽  
Woo-Jin Chung ◽  
Hyun-Woo Han ◽  
...  

HighlightsRattling of tractor power take-off drivelines can be detrimental to operators.A novel driveline model, which includes a torsional damper, was constructed.The behavior of the model was validated against that of an actual tractor driveline.The validated model was used to determine the optimal torsional damper parameters.These optimal parameters were validated by laboratory tests.Abstract. Rattle noise and high levels of vibration in agricultural tractors lower the productivity of the operators and may cause serious health issues in them. This study examined a method for preventing resonance and reducing the torsional vibration that causes rattling in tractor power take-off (PTO) drivelines in the idle state using a two-stage torsional damper. The PTO driveline was simplified to a 6-DOF model based on the principle of equivalent mass moment of inertia using commercial simulation software. The variations in the angular velocity of the PTO drive shaft in an actual tractor were measured and compared to the simulation results using a single-stage torsional damper to validate the model. Using this validated PTO driveline model, the pre spring of a two-stage torsional damper was investigated to determine its optimal torsional stiffness to minimize torsional vibration. The simulation results showed that the variations in the angular velocity of the PTO drive shaft decreased as the torsional stiffness of the pre spring decreased; accordingly, an appropriate torsional stiffness reduced the variation in the angular velocity delivered to the PTO drive shaft. The optimal torsional stiffness of the pre spring was determined by considering the manufacturing limitations of the torsional damper and the magnitude of the input engine torque. A pre spring with this optimal torsional stiffness was installed on an actual PTO driveline to measure the angular velocity transmissibility, which was the ratio of the variation in the angular velocity of the engine flywheel to the variation in the angular velocity of the PTO drive shaft, and the results were compared with those of the simulation. When the angular velocity of the engine was 850 rpm, the angular velocity transmissibility of the PTO drive shaft was 0.4 in the actual test, similar to the value of 0.29 obtained using the simulation. Thus, the simulation-optimized pre spring was able to avoid the resonance domain, while considerably reducing the torsional vibration that leads to rattling. The results of this study support the safe operation of agricultural tractors and guide the evaluation of torsional damper configurations of different vehicles. Keywords: PTO driveline, Resonance, Simulation model, Torsional damper, Torsional vibration, Tractor rattle.


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