Identification of a spinning projectile controlled with gasodynamic engines is shown in this paper. A missile model with a measurement inertial unit was developed from Newton’s law of motion and its aerodynamic coefficients were identified. This was achieved by applying the maximum likelihood principle in the wavelet domain. To assess the results, this was also performed in the time domain. The outcomes were obtained for two cases: when noise was not present and when it was included in the data. In all cases, the identification was performed in the passive mode, i.e., no special system identification experiments were designed. In the noise-free case, aerodynamic coefficients were estimated with high accuracy. When noise was included in the data, the wavelet-based estimates had a drop in their accuracy, but were still very accurate, whereas for the time domain approach the estimates were considered inaccurate.
The article presents the analysis of the impact point dispersion reduction using lateral correction thrusters. Two types of control algorithms are used and four sources of uncertainties are taken into account: aerodynamic parameters, thrust curve, initial conditions and IMU errors. The Monte Carlo approach was used for simulations and Circular Error Probable was used as a measure of dispersion. Generic rocket mathematical and simulation model was created in MATLAB/Simulink 2020b environment. Results show that the use of control algorithms greatly reduces the impact point dispersion.
Stability and performance are crucial characteristics for aerospace vehicles. The ability to investigate the aerodynamics and performance of rockets gives an insight into their stability before flight and the potential for design and performance enhancements. For the past 13 years, the rocketry Division within the students’ space Association of Warsaw University of technology has been developing sounding rockets of different designs and mission profiles. Two rockets have been chosen for the CFD (Computational Fluid Dynamics) campaigns, FOK and Twardowsky. This paper describes the mathematical model of aerodynamic loads used by the Division for sounding rocket simulation, followed by CFD campaigns for the two rockets. The results of the CFD analysis are then used to calculate the rockets’ aerodynamic derivatives according to a previously defined mathematical model.
Bezzałogowe statki powietrzne typu quadrotor znajdują obecnie coraz więcej zastosowań. Jednym z najważniejszych ograniczeń bezzałogowych wiropłatów jest niewielki zasób energii dostępnej na pokładzie, co przekłada się na małą długotrwałość lotu. Celem pracy było stworzenie modelu symulacyjnego mogącego służyć do badania wykorzystania energii przez quadrotora oraz planowania jego trasy przelotu. Platforma testowa wyposażona została w redundantne jednostki nawigacji bezwładnościowej, odbiornik systemu nawigacji satelitarnej, telemetrię oraz kamerę. W celu zbadania dynamiki lotu quadrotora opracowano model matematyczny o sześciu stopniach swobody. Parametry modelu zostały wyznaczone poprzez badania eksperymentalne w warunkach laboratoryjnych. Stworzono model zużycia energii przez silniki elektryczne oraz podsystemy pokładowe, jak również model akumulatora pokładowego. Przedstawiono strukturę autopilota. Stworzony model matematyczny został zaimplementowany w środowisku MATLAB/Simulink, a następnie zwalidowany w oparciu o dostępne wyniki badań w locie. Opracowane narzędzie obliczeniowe może zostać wykorzystane w praktycznych zastosowaniach do zadań planowania i optymalizacji trajektorii pod kątem minimalizacji zużycia energii.
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