Showing papers in "Aerospace Science and Technology in 2020"

TL;DR: In this article, the wave propagation in functionally graded metal foam plates reinforced with graphene platelets (GPLs) is studied, where various types of porosity and GPL distribution are taken in account.

TL;DR: A flight controller for a fault-free quadrotor is proposed which has a similar structure compared with the fault-tolerant one and two estimation methods for external disturbance and model uncertainties are applied to enhance the robustness of the proposed flight controller.

TL;DR: In this article, the impact of the wedge shock generator on the fuel mixing performance inside the combustor at the supersonic flow of M = 4 was investigated using a three-dimensional model with a structure grid.

TL;DR: An intelligent cooperative mission planning scheme to search and attack the time-sensitive moving targets in uncertain dynamic environment, by using a hybrid artificial potential field and ant colony optimization (HAPF-ACO) method.

TL;DR: A model-free reinforcement learning strategy is proposed for training a policy for online trajectory planning without establishing the dynamic and kinematic models of the space robot.

TL;DR: In this article, numerical simulations are applied to study the influence of the sinusoidal shock generator on the flow structure of the multi-hydrogen jet at supersonic crossflow.

TL;DR: In this article, the deformation behaviors and energy absorption of reentrant auxetic lattice cylindrical shells and the SILICOMB shell in different crushing velocity were investigated.

TL;DR: In this paper, a new dynamic model of the rotating tapered cantilever cylindrical panel with the graphene coating layers is developed to investigate the vibration characteristics of a rotating pretwisted tapered blade.

TL;DR: The effectiveness of the proposed active fault-tolerant control strategy is validated through real experiments based on a quadrotor helicopter subject to actuator faults and model uncertainties and its advantages are demonstrated in comparison with a model-based fault estimator and a conventional adaptive sliding mode control.

TL;DR: A new self-adaptive meta-heuristic based on decomposition is specifically developed for this many-objective optimisation problem for an unmanned aerial vehicle (UAV) posed with 6 objective functions: take-off gross weight, drag coefficient, take off distance, power required, lift coefficient and endurance subject to aircraft performance and stability constraints.

TL;DR: In this paper, the mixing performance of the multi-hydrogen jets at supersonic airflow when the downstream step exists in the downstream of the jet CFD simulations are conducted to disclose the feature of multi jets when a downstream step is applied.

TL;DR: A two-level quasi-distributed control framework is proposed for realizing the continuous control of a UAV swarm in two defined surveillance phases and an optimal high-level strategy combination is identified.

TL;DR: In this article, a moving extremum surrogate modeling strategy (MESMS) is proposed in respect of multi-physics coupling with various dynamics/uncertainties to improve the dynamic reliability analysis of complex structures like turbine blisk.

TL;DR: In this paper, a flag-flutter based piezoelectric energy harvester is modeled based on fluid-structure interaction (FSI) that represents an important area of research for the development of innovative energy harvesting solution.

TL;DR: In this article, the authors performed an experimental analysis of base pressure in suddenly expanded compressible flow from nozzles at different Mach numbers and found that microjets are efficient when the flow is under the influence of a favorable pressure gradient.

TL;DR: The efforts of this study provide the efficient method and model to optimally design the complex operating assembly relationship, and thereby enrich mechanical reliability method.

TL;DR: In this paper, the deformation patterns of double arrowed honeycomb (DAH) under high and low velocity impact are compared, which shows there is a great difference between them.

TL;DR: In this paper, the authors present a guidance law that uses observations consisting solely of seeker line-of-sight angle measurements and their rate of change, and demonstrate that the policy performs better than augmented zero-effort miss guidance with perfect target acceleration knowledge.

TL;DR: A novel technique is presented, combining neural network and Kalman filter, for state estimation that provides the estimates of the system states while also estimating the uncertain or unmodeled terms of the process dynamics.

TL;DR: The simulation results show that the UAV swarm can generate, maintain and reconstruct the desired formation in a real-time distributed manner while avoiding obstacles effectively.

TL;DR: In this paper, the authors proposed the spindle-like and butterfly-like bluff bodies by coupling both the vortex-induced vibration (VIV) and galloping phenomena to enhance the low-speed wind energy harvesting.

TL;DR: This paper presents a data-driven approach for predicting the pressure distribution over airfoils based on Convolutional Neural Network (CNN), and utilizes a universal and flexible parametrization method called Signed Distance Function to improve the performances of CNN.

TL;DR: Simulation results demonstrate that the ICA can make UAVs with different initial states form the specified formation while satisfying all the constraints, and a safe and efficient flight for UAV formation can be ensured with the obstacle avoidance algorithm.

TL;DR: The efforts of this study provide a learning-based reliability analysis way (i.e., ENLM) for the motion reliability design optimization of flexible mechanism and enrich mechanical reliability theory.

TL;DR: It is shown that by using Lyapunov methods the synchronization tracking control is achieved even when multi-UAVs simultaneously encounter wind effects and actuator faults.

TL;DR: The obtained characteristics prove the finite time stability and robustness of the new automatic landing system even in the case of landing affected by wind gusts and errors of the sensors.

TL;DR: In this article, a numerical solution for free vibration analysis of nanocomposite conical shells is proposed, where the First-Order Shear Deformation Theory (FSDT) is used to achieve the governing equations.

TL;DR: In this article, a non-inclusive Chebyshev metamodel (CMM) is implemented on deterministic analysis using discrete singular convolution (DSC) method with excellent computational efficiency and accuracy, which is used to obtain both deterministic and probabilistic results including probability density functions, cumulative density functions (CDFs), means and standard deviations of the critical buckling load.

TL;DR: The three main shape sensing methods, the Modal Method, the Ko's displacements theory and the inverse Finite Element Method, are presented and show different characteristics that make them suitable for different applications, depending on the level of accuracy and the number of strain information required.

TL;DR: In this paper, a non-local model for free vibration and thermal buckling analysis of rotating temperature-dependent functionally graded (FG) nanobeams in thermal environment is developed by introducing an axial nonlinear second-order coupling deformation based upon the Eringen's nonlocal elasticity theory (ENET) and Euler-Bernoulli beam theory (EBT).