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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 distributed synchronization control problem of multiple quadrotor aircraft in the form of leader-follower structure is considered in this paper. Based on the method of backstepping design, a novel distributed consensus control algorithm is proposed. Firstly, for the position control subsystem, by Proportional-Differential control and the theory of communication topology graph, a consensus control...
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...
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...
Aircraft need to be separated from other aircraft by either a minimum vertical distance of 1000ft or by a minimum horizontal distance of 5NM to avoid mid-air collisions. Traffic Alert and Collision Avoidance System (TCAS) work well as a tactical safety backups to avoid collision, but cannot perform separation assurance. This paper presents the design aspects of system that would predict separation...
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...
A path optimization strategy for generating energy-aware soaring trajectories for small Unmanned Aerial Systems (sUAS) is presented. Soaring paths are generated using a point-mass dynamics model and deterministic local wind field. The dynamics model, periodic constraints, and an energy-aware cost function are combined into a nonlinear program (NLP) framework to generate energy optimal paths. A dynamics...
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...
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...
One of the most challenging problems in aerospace engineering is the analysis of the separation trajectories by which a missile ejected from an aircraft. The attitudes of some static unstable missile are divergent quickly due to aerodynamic interference by the aircraft. Therefore, it is disadvantageous to missile's separation from aircraft safely. The attitude control strategy must be applied to avoid...
This paper addresses the decision problem for terrain-following flights (TFFs) of aircrafts in unknown environments, where global trajectory planning methods cannot be applied directly. In such cases, the uncertainties and complexities of the terrain are needed to be dealt with especially. In order to realize the automatic generation of a terrain-following (TF) controller, a self-learning TF method...
A new ground moving target indication algorithm for single channel Circular Synthetic Aperture Radar (CSAR) is presented and evaluated by airborne CSAR dataset. The algorithm is based on overlap subaperture magnitude images. The subaperture image can be regarded as the background image (clutter) plus the foreground image (moving target). The background image is obtained by median filter. Then the...
In order to solve the problem of high computational complexity in the target tracking, this paper combines mean shift with the particle filter algorithm. The detailed process of establishing the target model is proposed. According to the results, the approach can constantly detect the exact position of target. Experimental results show that the proposed method has better performance compared with...
Under the coupling effect between guidance system and control system, the performance of traditional guidance and control method is limited. Therefore, integrated guidance and control (IGC) method is proposed to solve the problem. This method is characterized by the guidance loop and control loop which are considered as a whole part in accordance with the information of the relative motion between...
The physical ground simulation of space defense confrontation is under the contractible time and space coordination of real world. The theoretical foundation of simulation is determined by the uniform constrains that ensured the similarities of geometrical and physical quantities mapping in the two spaces. Under the architectures of space vector linear similarity and time uniform elapse, the sufficient...
This paper deals with a one-versus-one air combat algorithm that considers the direction of the lift vector of an unmanned combat aerial vehicle(UCAV). The air combat situation discussed in this study assumes that a gun-fight takes place within visual range(WVR), thus the air combat algorithm will perform the maneuver to chase the enemy's tail. The air combat algorithm previously proposed by the authors...
A modern class of small fixed-wing unmanned aerial vehicles are physically capable of performing exceptional aerobatic maneuvers. This paper presents a methodology for including one of the more functional of these maneuvers, the knife-edge, in motion planning. This is achieved by separating the top-level motion planner from the dynamics and control of the knife-edge maneuver. By coupling feedback...
A formation flight controller can be used in a UAS fleet to avoid collision, reduce fuel consumption, or to execute interactions between the UASs, such as autonomous aerial refueling. In this paper, an autonomous formation flight (AFF) controller based on non linear dynamic inversion (NLDI) and a non-colliding path planner are proposed. The proposed NLDI AFF extends a NLDI controller found in literature...
Appearance of tragedies like the lost flight MH370 should be eliminated or reduced and in this paper a technique based on the Doppler shift of radio sources of opportunity is suggested as an alternative technique of tracking aircraft. Such systems are based on simultaneous analysis of the Doppler shift caused by aircraft moving with respect to multiple radio signal sources and network of receivers...
This paper deals with the Terminal Control Area Aircraft Scheduling Problem and the Aircraft Trajectory Optimization Problem for landing operations in a busy terminal control area. The first problem requires to compute a conflict-free schedule for all aircraft minimizing the overall aircraft delays, while the second deals with the computation of a landing trajectory for each aircraft which minimizes...
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