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This paper aims to work exhibits the temperature distribution over the surface of the workpiece during plasma arc cutting process.

The moving heat source is taken into consideration for calculating the heat created by plasma arc. The heat is generated at the plasma – liquid metal boundary. The heat of fusion is also considered for estimation because of molten layer separates the plasma and solid layer. This causes to hamper the heat transfer towards the melting front. Eliminating the heat resistance may calculation error at high cutting speed. Power required to melt the material depends on the speed of the cut.

Higher cutting speed increases the power required. The temperature drop over the layer of molten front increases as the speed of cut increases at higher Peclet number. Different thickness of the molten layer was taken for calculation i.e. zero thickness, 10 and 20 per cent.

The estimated results are shown in non-dimensional form. So, the method can be applied for any other types of material.

SINCE the introduction of plasma are welding, in its simplest form, the process and technology has made extremely rapid strides. It is the object of this paper to explain, in simple terms, the various types of plasma systems, equipments and applications for which they can be used.

Plasma arc cutting (PAC) is extensively applicable for cutting the materials in faster speed with better accuracy in different manufacturing industries. The cutting of sailhard steel plate plays a great challenge in plasma arc cutting process.

In this investigation, a special abrasion-resistant steel known as sailhard of 20 mm thickness plate has been cut by PAC machine. Cutting current, stand-off distance, cutting speed and gas pressure were selected as cutting parameters. The corresponding responses focused for this study are material removal rate, kerf and chamfer. L30 orthogonal array based on a central composite design (CCD) of response surface methodology (RSM) was used to design the run of the experiment. For predicting and modeling of optimal cutting conditions, a hybrid approach of desirability function-based response surface methodology (DRSM) was acquainted.

The result of this study determines that desirability index (DI) was affected significantly with the machining parameter as well as their interaction. A confirmation test was carried out to analyze the degree of effectiveness of DRSM technique.

In PAC, the selection of process parameters and effect of that parameter on the output responses is of greater value because of the selection of best cutting condition.

The purpose of this paper is to develop a mathematical tool and an experimental platform to be able to reconstruct thermal plasmas in three dimensions (3D) in order to characterize 3D plasma and to validate models in 3D. Indeed, a lack of experimental data allowing validating 3D models exists.

The paper is realized with a transferred argon arc configuration. The 3D character is due to the form of the cathode electrode. The reactor design is defined by a previous theoretical study. This previous paper has shown that tomographic method through four views allows reconstructing 3D object. The light emitted by the plasma along four directions (four windows) is so spectrally resolved and treated by a multiplicative algebraic reconstruction technique algorithm. Following the emissivity profiles, two methods are used, the absolute line intensity method, and for an out off‐axis maximum of the emissivity the Folwer Milne method.

After a validating approach of the optical measurements in symmetrical configuration using Abel inversion, the reconstructed method is used. The results show the possibility of the tomographic method spectrally and spatially resolved to be applied to thermal plasma in order to characterise the medium and to validate the 3D models. The plasma medium is well described with a spatial resolution equal to 0.2 mm.

The method is applicable to thermal plasma presenting high emissivity. Even if the theoretical reconstruction method is applied to low temperatures or to theoretical plasma presenting out off‐axis of emissivity, future researches need to be performed to analyse the ability of the method to spatially resolve the areas presenting low emissivity.

The paper's originality can be demonstrated by the poor number of studies in thermal plasma reconstruction in 3D. Studies on plasma imaging can be found but not spectrally resolved. The special care on the spectral acquisition along the plasma radius combined with the tomographic reconstruction method lead to the originality of this paper.

Nuclear waste tanks need to be cut into pieces before they can be safely disposed of, but the cutting process produces a large amount of aerosols with radiation, which is very harmful to the health of the operator. The purpose of this paper is to establish an intelligent strategy for an integrated robot designed for measurement and cutting, which can accurately identify and cut unknown nuclear waste tanks and realize autonomous precise processing.

A robot system integrating point cloud measurement and plasma cutting is designed in this paper. First, accurate calibration methods for the robot, tool and hand-eye system are established. Second, for eliminating the extremely scattered point cloud caused by metal surface refraction, an omnidirectional octree data structure with 26 vectors is proposed to extract the point cloud model more accurately. Then, a minimum bounding box is calculated for limiting the local area to be cut, the local three-dimensional shape of the nuclear tank is fitted within the bounding box, in which the cutting trajectories and normal vectors are planned accurately.

The cutting precision is verified by changing the tool into a dial indicator in the simulation and the experiment process. The octree data structure with omnidirectional pointing vectors can effectively improve the filtering accuracy of the scattered point cloud. The point cloud filter algorithm combined with the structure calibration methods for the integrated measurement and processing system can ensure the final machining accuracy of the robot.

Aiming at the problems of large measurement noise interference, complex transformations between coordinate systems and difficult accuracy guarantee, this paper proposes structure calibration, point cloud filtering and point cloud-based planning algorithm, which can greatly improve the reliability and accuracy of the system. Simulation and experiment verify the final cutting accuracy of the whole system.

The purpose of this paper is to analyze the characteristics of sound during gas tungsten argon welding (GTAW), which is very important to effectively monitor the welding quality in future by using the information extracted from sound.

The hardware used in the experiment is described. Then the paper researches the influence of welding techniques (gas flow, welding speed, welding current, and arc length) on arc sound and the distribution of the welding sound field. Finally, the relation between welding power and sound are studied based on Fourier transforms and recursive least square methods.

The sound pressure is affected greatly by gas flow, arc length, and current; welding sound source obeys the dipole model; the sound can be better predicted when the three orders derivative of the welding power are combined together.

This paper provides a new insight into welding sound resource model and a detailed analysis of the influence of the welding sound caused by welding techniques.

Discusses the requirement for teleoperation and the optimum division of tasks between the human operator and the robot controller. Concludes that a combination of adaptive autonomous control with teleoperation will allow operators to take a more supervisory role.

Considers the use of robotics in the workplace as a means of protecting workers from exposure to hazardous substances, environments and physical agents. Gives examples of robots being used to handle radioactive material and working in the high dust exposure atmosphere of a plastics factory. Emphasizes the need to use a systematic approach to obtain the maximum health and safety benefit from automation of work, and outlines the areas to be considered. Describes the role of the British Robotics Association in realizing the potential benefits to occupational health from the application of robotic workstations and looks at areas of industry where this might be implemented. Concludes that using robotics to bring about health and safety benefits as well as production efficiency and quality improvement is a wide and new area for industry to develop.

The purpose of this study aims to obtain excellent products, consistent investigation and manufacturing process control which are the preconditions that organizations have to consider. Nowadays, manufacturing industry apprise process capability index (C_pi) to evaluate the nature of their things with an expect to enhance quality and also to improve the productivity by cutting down the operating cost. In this paper, process capability analysis was applied during wire electrical discharge machining (WEDM) of titanium grade 6, to study the process performance within specific limits.

Four machine input parameters, namely, pulse ON time, pulse OFF time, wire feed and wire tension, were chosen for process capability study. Experiments were carried out according to Taguchi’s L27 orthogonal array. The value of C_pi was evaluated for two machining attributes, namely, average surface roughness and material removal rate (MRR). For these two machining qualities, single response optimization was executed to explore the input settings, which could optimize WEDM process ability.

Optimum parameter settings for average surface roughness and MRR were found to be TON: 115 µs, TOFF: 55 µs, WF: 4 m/min and WT: 6 kg⁻F and TON: 105 µs, TOFF: 60 µs, WF: 4 m/min and WT: 5 kg⁻F.

Process capability analysis constantly checks the process quality through the capability index keep in mind the end goal to guarantee that the items made are complying with the particulars, providing data for product plan and process quality enhancement for designer and engineers, giving the support to decrease the cost of item failures.