MIMO-OFDM models of RPAS communication channels based on LTE Standard were built. Dependencies of the BER on the SNR for Extended Pedestrian A and Extended Vehicular A models using 2-by-2 multiple antennas were obtained. Dependencies of the BER on the SNR for different levels of Frequency Offset at satellite transponder were studied.
Tungsten inert gas (TIG) welding is a multi-input and multi-output variant process. The input process parameters and other factors of welding process interact in a complicated manner and influence the weld quality – directly or indirectly. Keeping this in mind, the present work has been planned to study the impact behaviour of TIG weldment through experiments, analysis and optimization. Experimental runs have been considered as per Box-Behnken design of response surface methodology (RSM). Based on the recorded data, the mathematical models have been developed to study the effect of process parameters on impact strength. ANOVA has been utilized to identify the influence of input process parameters on the response i.e. impact strength. RSM and cuckoo search optimization (CSO) algorithm have also been applied to optimize the impact strength.
This paper presents a simple-to-use system for estimating non-measurable components of crane state vector considering parameter changes. To obtain them, it is possible to use a numerical derivative, where the measurement noise causes great inaccuracies, or the Luenberger observer and Kalman filter, which require knowledge of the dynamics of the controlled system, which is constantly changing with the crane.
In various machining processes, the vibration signals are studied for tool condition monitoring often referred as wear monitoring. It is essential to overcome unpredicted machining trouble and to improvise the efficiency of the machine. Tool wear is a vital problem in materials such as nickel based alloys as they have high hardness ranges. Though they have high hardness, a nickel based alloy Inconel 718 with varying HRC (51, 53, and 55), is opted as work material for hard turning process in this work. Uncoated carbide, coated carbide and ceramic tools are employed as cutting tools. Taguchi’s L9 orthogonal array is considered by taking hardness, speed, feed and depth of cut as four input parameters, the number of experiments and the combinations of parameters for every run is obtained. The vibration signals are recorded at various stages of cutting, till the tool failure is observed. Taking this vibration signal data as input to ANOVA and Grey relation analysis (GRA) which categorizes the optimal and utmost dominant features such as Root Mean Square (RMS), Crest Factor (CF), Skewness (Sk), Kurtosis (Ku), Absolute Deviation (AD), Mean, Standard Deviation (SD), Variance, peak, Frequency and Time in the tool wear process.
Most of the people living in developing or less developed countries have limited earning to provide somehow their basic needs and usual staff. Carrying goods is a regular task in life and several products have been invented to minimize efforts in this purpose. However, the price and features of most available products are out of the reach for the people of limited earnings. Stair climbing cart is very useful for those houses where a lift is not available. In this research, a modified mechanical design with eight wheels providing pause-rest feature has been represented with the equations of pulling force, constraints of stair dimensions and climbing mechanism. The ‘House of Quality Diagram ‘(QFD)’ has been added to accomplish the vision of further market research and customer satisfaction. The factor of safety and different types of stress have been determined for different types of loads and conditions. In addition, the details of the material with dimension, design and feasibility analysis have led this research to uniqueness.
The aim of this study was to investigate the usage of Dynamic Image Analysis for determination of size, shape and distribution of granules of microcrystalline cellulose, created by high shear granulation. A series of experiments was carried out to analyse the effect of process parameters on a created granule morphology. The amount of the granulation liquid and speed of the impeller have a significant effect on the median size granule value, the sphericity, the granule distribution width, but also on the granulation process yield.
The melting conditions of the electrode wires and the structure of coatings, obtained by the electric arc spraying method depending on the pressure of the spraying air flow, are analysed in the current paper. The effect of air pressure on the spraying angle of the flow of melted metal droplets is demonstrated. It is established that due to the decrease in this spraying angle, the temperature of the droplets increases. In addition, high-speed airflow is more easily captured by smaller molten metal droplets and during the contact with the substrate surface their deformations were more strongly. Due to such phenomenon, the porosity of the coatings was reduced and the number of lamellae, welded to each other, increased. With the increasing pressure of the air flow, the thicknesses of the lamellae were decreased, however, the amount of the oxide phase in the coatings has increased. As a result, the hardness, wear resistance and cohesive strength of the coatings, obtained at a higher pressure of the air flow, have increased, and the level of residual stresses of the first kind in them decreased.