Applied Mechanics and Materials Vol. 186

Abstract: This paper presents the development and optimization of control parameters of an autonomous robot capable of traversing a planar surface without going beyond the surface boundary. Based on standard Lego® design, the proposed robot travels on surfaces with different geometrical shapes and collects data on the basis of which the perimeter can be redrawn using MATLAB. The remote detection capabilities of this robot can find its application in construction, defence surveillance operations, geological and space research and industry as an automated process of measurement, especially when the surface being measured is beyond human reach. The robot detects the edge using a color sensor which differentiates the color of the surface from its boundary. After detecting an edge point, the robot retracts and turns to detect an edge point in another direction. The length of the paths traversed by the robot from one edge point to another serves as the input data to the MATLAB program which computes this data and transforms it to a plot of the perimeter. Experiments conducted demonstrate the optimal values of parameters for control of motion of the robot to give satisfactory results with minimal power and time expenditure.

Abstract: This document deals with optimization of flexible pneumatic actuator (APF), used to develop a force of thrust. It was intended for efficient routing of strain and was carried out for research on materials used, shape of pressurized chamber, and the introducing of no elastic materials for fittings and fixtures. This study was focused on the properties of compressed air and makes a small pneumatic actuator that develops useful force by expanding the volume of a pressurized chamber made out of elastic material. The research performed on this type of actuator has led to a small APF (10-20 mm) with more than satisfactory results, with a wide range of uses in automation, robotics, medicine, aviation and more.

Abstract: The aeroelastic behavior of high aspect ratio wings in an incompressible flow is investigated. The nonlinear nonplanar bending-bending-twisting motions of beam theory is used for the structural equations assuming large deformations with small strains, small Poisson effects, inextensional beam theory, and linear elastic material characteristics by neglecting warping and shear deformation. An Unsteady nonlinear aerodynamic static stall model based on the Wagner function is introduced and then is used for determination of aerodynamic loading of the wing. In this aerodynamic model, the static lift curve vs. angle of attack is approximated by a piece-wise curve and for each linear part of this curve a corrected Wagner theory is used. Combining these two types of formulation yields fully nonlinear integro-differentials aeroelastic equations of motion. The governing equations will be solved to predict the nonlinear aeroelastic response of a wing in the stall and post stall regions using Galerkin's method and a numerical method without the need of adding any aerodynamic state-space variables and their corresponding equations. The obtained equations are solved for some test cases and the obtained results are compared with the results given in the literature. Also a study is done to show effects of nonlinear aerodynamic static stall model on the limit cycle oscillations.

Abstract: The UAV prototype flight unit for monitoring the natural environment has imposed a number of corrections on the shape and size of the external configuration, stability in flight and trying different types of propeller and engine drive. For different types of propeller tested, the static pressure distributions were determined for different values of the forces on the device body. Simulations of flow and pressure distributions have led to an analysis of differences between the forces created in three different cases imposed by the diameter propeller airflow created by the device.

Abstract: This research endeavor probes into the implementation of navigation solution using the signals of Global Navigation Satellite System (GNSS) from the Garmin GPS-25 OEM board after getting the raw data in the NMEA format. The position information obtained by the receiver is compared with the navigation algorithm implemented in MATLAB. The Ionospheric, Tropospheric and relativistic clock errors are incorporated to achieve the required accuracy. The Least square iterative algorithm is applied to get the position information. The geometric, position and time dilution of precisions; GDOP, PDOP and TDOP respectively are also compared and analyzed. The GNSS structure, the signal in space, the sources of positioning errors, the pre-processing techniques and data formats are also presented to complete the problem. The analytical treatment validates the problem solution too.