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In the past years Unmanned Aerial Vehicles (UAVs) have received considerable attention from the scientific community. The trajectory control is a fundamental block that a flight control system must properly address. However, a recent approach based on fractional calculus has shed a new light into this area, allowing the well tested PID controller to be improved even further. One advantage is that...
This paper investigates the finite-time consensus tracking problem for a group of quadrotor aircraft with a leader-follower structure. Based on finite-time algorithms, the finitetime position controller and attitude controller are designed respectively in this note. Based on homogenous system theory and Lyapunov theory, the finite-time stability of the closed-loop systems is given and it is shown...
The System Wide Information Management (SWIM) is to achieve system-wide interoperability and enable seamless information sharing for global Air Traffic Management (ATM). In this paper, to improve aircraft tracking accuracy, the SWIM concept-oriented information integration based on the Big Data analysis is discussed. By incorporating the trajectory information into the aircraft tracking system, the...
The landing accuracy of a Mars entry vehicle will be degraded duo to uncertain factors in the atmospheric entry process and a novel composite guidance law, having a composite hierarchical framework, is presented to improve the landing accuracy in this paper. It could eliminate the constraint that maximum boundary value of uncertain factors must be known in advance in the multiple sliding surface guidance...
Flatness approach is a straightforward method to solve the control problems of flat systems which are a class of systems whose states and control inputs can be expressed by the so-called flat outputs. Some results about flatness of systems and the advantages of studying flatness approach are presented in this paper. By using flatness approach, the controllability and other control problems for some...
The characteristics of a simple generator of pseodo-random numbers used in IRE NASU for the system of astronomical observation modeling are studied. The principle of the generator is based on the fact that the set of all n-bit binary words excepting 0 forms a cyclic additive group of 2n-1 order with cyclic addition as a group operation. The tests are demonstrating the high quality of this generator.
Maneuvering aircraft tracking under low accuracy observations is a challenge. To solve this problem, we constructed the corresponding dynamic model for different flying states of aircraft. Then we combined the models of different flying states into single one. Since an accurate dynamic model is a strong constraint for the flying trajectory of aircraft, the trajectory should follow the dynamic characteristic...
In this paper, we address the data collection planning problem for fixed-wing unmanned aircraft vehicle (UAV) with a limited travel budget. We formulate the problem as a variant of the Orienteering Problem (OP) in which the Dubins airplane model is utilized to extend the problem into the three-dimensional space and curvature-constrained vehicles. The proposed Dubins Airplane Orienteering Problem (DA-OP)...
This paper proposes a new method for tracking the whole trajectory of a ballistic missile from launch to impact on the ground. Multiple state models are applied for the ballistic missile movement descriptions during different phases, while the transition probabilities are modelled in a state-dependent way. A radar sensor is applied to obtain the missile range, azimuth angle and elevation angle measurements...
This paper presents a design methodology for the rejection of wind gusts during flight. The proposed application is based on the Simple Adaptive Controller (SAC) methodology, but differs from other SAC applications in the sense that the reference model utilised is an Unknown Input Observer (UIO). As a consequence, the adaptive controller is fed by an estimate of the wind gust and will only act in...
This paper presents a tracking controller for a long pneumatic transmission line modeled by a bidirectionally coupled system of partial differential equations (PDEs) and ordinary differential equations (ODEs). The feedforward part of the controller is designed by applying a flatness-based approach for hyperbolic PDEs to a second-order quasilinear model of the pneumatic system. The stabilizing feedback...
Collision Avoidance is considered as the final layer of safety to prevent mid-air collisions when all other avoidance measures have failed. These methods are gaining importance, in particular in recent years. The ultimate goal is to replace the already obsolete TCAS system, which is not included in the NextGen programme. Additionally, the dynamic UAS market in civil, commercial and military sectors...
In this work we propose a framework for data-driven crowd simulation starting from a small set of trajectories. To model the macroscopic behavior, our method extracts pedestrian trajectories from real videos, clusters all trajectories of pedestrians who intend to reach the same goal, and computes the velocity field associated with each exit region in the scene to guide virtual agents toward their...
This paper presents a method for extending the generalized polynomial chaos method with stochastic collocation, so that expansion coefficients for further continuous distributions other than the standard distributions of the generalized polynomial chaos can be calculated. This is achieved by using a Gaussian mixture model to approximate the desired arbitrary continuous input distribution. This incorporation...
Three-degree-of-freedom trajectory tracking of the stratospheric airship is investigated. With a simplified planar dynamic model, an adaptive backstepping sliding mode controller is designed to keep the airship to globally asymptotically track a desired trajectory. Lyapunov functions are used to ensure the tracking performance when model parametric uncertainty and external disturbances exist. Simulation...
Haze is a negative consequence of forest and land fires that caused many health problems and contributed on global warming. This study aims to generate haze trajectory from peatland fires in South Sumatra in October 2015. We used the HYPLIT model to generate haze trajectories with hotspot sequences as the initial points of trajectory. The simulation was performed using the package Opentraj which is...
In view of the mars reentry problem under external disturbance, this paper presents a guidance algorithm based on drag tracking. First of all, the reference drag is calculated based on the reentry model and the reference trajectory. Secondly, estimated disturbance via the sliding mode observer, this paper improve the accuracy of the controller parameters and increase the anti-disturbance capability...
Being as the pivot of avionics system, Flight Management System (FMS) plays an important role in flight planning, trajectory prediction, navigation and guidance of aircrafts. Aiming at researching the functions and validations of FMS, the advanced FMS simulation is constructed. Performance Based Navigation (PBN) and Trajectory Based Operation (TBO) require high-fidelity and high-accuracy data, of...
This paper will discuss recent improvements made to the Monte Carlo Scene (MCScene) code to enable limb-viewing scenarios and situations where the sun is below the horizon. MCScene is a high-fidelity model for full optical spectrum (UV through LWIR) hyperspectral image (HSI) simulation. MCScene generates HSI scenes for algorithm validation, utilizing a Direct Simulation Monte Carlo (DSMC) approach...
A predictor-corrector entry guidance method satisfying the constraints of no-fly zone and waypoint is proposed in this paper. First, Gauss pseudospectral method is used to generate a reference trajectory. Based on the reference trajectory some reference points are selected which partition the entry process into several subsections. Then a predictor-corrector guidance law is developed. The trajectory...
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