The evaluation of propulsion systems used in UAVs is of paramount importance to enhance the flight endurance, increase the flight control performance, and minimize the power consumption. This evaluation, however, is typically performed experimentally after the preliminary hardware design of the UAV is completed, which tends to be expensive and time-consuming. In this paper, a comprehensive theoretical UAV propulsion system assessment is proposed to assess both static and dynamic performance characteristics via an integrated simulation model. The approach encompasses the electromechanical dynamics of both the motor and its controller. The proposed analytical model estimates the propeller and motor combination performance with the overarching goal of enhancing the overall efficiency of the aircraft propulsion system before expensive costs are incurred. The model embraces an advanced blade element momentum theory underpinned by the development of a novel mechanism to predict the propeller performance under low Reynolds number conditions. The propeller model utilizes XFOIL and various factors, including post-stall effects, 3D correction, Reynolds number fluctuations, and tip loss corrections to predict the corresponding aerodynamic loads. Computational fluid dynamics are used to corroborate the dynamic formulations followed by extensive experimental tests to validate the proposed estimation methodology.

The propulsion system has a dramatic effect on Unmanned Aircraft vehicles (UAVs) performance in addition to the indispensable function in creating a nonlinear flight simulation model for UAVs. Motivated by the problem of propeller modeling and selecting the highly appropriate propeller with affordable low computational time and power, this research focuses on carrying out a complete propeller performance assessment environment based on Enhanced Blade Element Theory (EBET). Contrary to the classical blade element theory (BET), the EBET considers the existence of the propeller angle of attack, as well as the free-steam velocity consequently accurate prediction of the aerodynamic loads furthermore The BET is reliable in moderate loading conditions and for reduced complexity geometries. In this regard, the APC 12X6E propeller is geometrically modeled based on digital scanning and manufacturer data furthermore operating conditions in the flight regimes. The propeller's static and dynamic performance characteristics are estimated to be used in UAV open-loop flight simulation model and to calculate the power coefficient. The assessment results show the efficiency of the proposed propeller simulated model.

This research demonstrates the procedure for servo control circuit implementation for the guided missile. Motivated by enhancing the performance of the guided missile servo system control circuit by using embedded systems and gaining the digital circuit advantages and, solving the problem of obsolete analog components. The proposed servo system. includes four servo pistons for driving the missile canard. A high-resolution gear potentiometer is used as position feedback for the missile fin. The guidance command converted from the polar form to cartesian and delivered as input to the microcontroller PIC18f4431 to control the pneumatic servo by generating corresponding pulse width modulation(PWM) to the driving circuit. In this regard System identification for the pneumatic servo system is carried out. In current work, a servo positioning system based on an embedded system was designed to achieve a deterministic time response and minimize the jitters around 155 μs for accurate guidance and control operation. The accuracy of the controlled system was verified using servo Automatic Test Equipment (ATE) and, the results show the enhancement in the platform performance based on digital implementation instead of the analog circuit.