Aircraft Trajectory Control Research Articles

Winch Traction Dynamics for a Carrier-Based Aircraft Under Trajectory Control on a Small Deck in Complex Sea Conditions

When the winch traction system of a carrier-based aircraft works under complex sea conditions, the rope and the tire forces are greatly changed compared with under simple sea conditions, and it poses a potential threat to the safety and stability of the aircraft’s traction system. The accurate calculation of the rope and tire forces of a carrier-based aircraft’s winch traction under complex sea conditions is an arduous problem. A novel method of dynamic analysis of the aircraft-winch-ship whole system under complex sea conditions is proposed. A multiple-frequency excitation is adopted to describe the complex sea conditions and the influences of pitching amplitude, and the rolling frequency on the traction dynamics of a carrier-based aircraft along the setting trajectory under complex sea conditions are studied. The advantages and disadvantages of a winch traction system with trajectory control and without trajectory control in complex sea conditions are analyzed. For realizing the trajectory control of the aircraft, the vector difference between the center of mass for the carrier-based aircraft and the position on the predetermined Bessel curve is calculated, so as to obtain the azimuth vector in the aircraft coordinate system. This research is innovative in the modeling of the whole system and the trajectory control of a carrier-based aircraft’s winch traction system under the complicated sea condition of the multi-frequency excitation. ADAMS (Automatic Dynamic Analysis of Mechanical System) is used to verify the correctness of the theoretical calculation for the winch traction. The results show that the complex sea environment has a certain influence on the winch traction safety of the aircraft; in the range of 10–15 s for the traction, the rope force amplitude of complex sea conditions under the multi-frequency excitation is 29.5% larger than that of the single-frequency amplitude, while the vertical force amplitude of the tire is 201.1% larger than that of the single-frequency amplitude. This research has important guiding significance for the selection of rope and tire models for a carrier-borne aircraft’s winch traction in complex sea conditions.

Computational analysis of data transmission models in satellite systems for aircraft trajectory control

The paper considers the application of the computational analysis of data transmission models in satellite systems for aircraft trajectory control. A system for monitoring the trajectory of aircraft using satellite communication systems Iridium and Inmarsat is presented. The scheme of communication between the aircraft board and the control tower takes into account the peculiarities of extreme conditions typical for the Arctic and the Far North. An example of calculating the probability of code combination transformations for an asymmetric channel with independent errors is considered. In this case, the calculations follow the provisions of the theorems of probability theory. Modeled data rates for satellite communication systems Iridium and Inmarsat. It is concluded that the Iridium and Inmarsat systems have a high data transfer rate and a low error rate, and their use as communication systems for transmitting data from an aircraft to an air traffic control center is justified.

Bi-criteria Aircraft Trajectory Optimization in Implementing the Area Navigation Concept

To solve a problem of bi-criteria optimization of an aircraft flight trajectory using the data of satellite navigation systems, the authors suggest an approach based on the game theory methods. The target was set to organize trajectory control with two partial criteria of optimality (desired track deviation and position-fixing error) minimized simultaneously. It is shown that the minima of individual partial criteria are generally achieved with different control inputs and hence with different flight path parameters so there is a need to form an additional strategy for decision making in a bi-criteria optimization problem taking into account existing restrictions. Based on the multi-criteria optimization methods, an algorithm for aircraft trajectory control was synthesized. The comparative analysis of the research results shows that the synthesized algorithms of optimal control based on the suggested approach make it possible to find a compromise solution for a multi-criteria trajectory optimization problem in the area of global navigational satellite system augmentation. Proposals were drawn up to construct spatial programmed trajectories aiming to high-accuracy navigational sightings.

Methods of trajectory control of observation in air-based angle-measuring two-position radio monitoring systems. Part 2. Gradient methods

To control and monitor the electronic situation, air-based passive angle-measuring two-position systems radio monitoring can be used. A feature of the functioning of these systems is the fact that the accuracy of the estimation of the coordinates and parameters of the movement of radio emission sources (RES) depends largely on the configuration of the relative position of the receiving positions placed on the aircraft and the RES. Therefore, the problem of optimization the relative position of aircraft and AIR is relevant, and various gradient methods of trajectory control of observation have been developed to solve this problem. Usually in two-position systems one aircraft is the leader, and the second one provides information support. To implement gradient methods, the control of the information support aircraft is organized in such a way that the error of determining the position of the RES at any time is minimal. To fulfill this condition, the information support aircraft must move along a special trajectory, the parameters of which are determined by an algorithm based on gradient optimization methods. The dependence of the error in determining the position of the RES on the relative position of the aircraft and RES and the direction finding accuracy is used as an target function. The article provides information on the gradient methods of trajectory control in the angle-measuring two-position systems, which provide the fastest increase in the accuracy of estimating the coordinates and parameters of the motion of RES for various conditions of practical application in a volume sufficient to obtain a general idea of the ways to solve the problem of trajectory control of an aircraft in the angle-measuring two-position systems. For the trajectory control of the information support aircraft, the gradient method of course guidance was first developed. This method is a relatively simple iterative procedure based on information about the gradient of the quality functional. The disadvantage of this method is the low accuracy of determining the coordinates of the RES at the initial moment of time with a relatively small distance of the aircraft from each other at the beginning of the guidance, as well as in the greater fuel consumption on board the information support aircraft compared to the leading aircraft during the guidance process. To eliminate this disadvantage, trajectory control methods have been developed for two situations of practical application of anglemeasuring two-position systems. The first situation occurs when there is a two-stage procedure of target guidance. At the stage of long-range guidance, aircraft are brought to the RES detection zone by commands from the control center. At the second (short-range) stage of guidance, after the detection of the RES signals by the direction finders of the aircraft, the process of self-homing of leading aircraft to the RES begins and information support for the task solution by other aircraft. For this situation, a modified gradient method of trajectory control of information support aircraft has been developed. The second method to eliminate the disadvantage of the gradient method involves the rejection of the distribution functions of guidance and information support between the aircrafts. It can be used in a situation where the guidance of the aircraft on the RES begins from the moment it is detected on aircraft board. At the same time, the solution of the problem of minimizing the RES location errors is assigned not to one information support aircraft, but simultaneously to both aircrafts. However, mentioned methods do not take into account possible restrictions on the movement of the information support aircraft when forming the control parameters of this aircraft, associated with the presence of dangerous zones for flights, as a result, the flight safety of this aircraft is not guaranteed. For flights in the presence of dangerous zones, the method of trajectory control of the aircraft on the course and the corresponding algorithm of trajectory control of information support aircraft based on the method of gradient projection of the target function has been developed. However, this technique does not guarantee that the flight of the information support aircraft will be carried out exactly on the border of the dangerous zone. In order to eliminate this disadvantage, the method of trajectory control based on the gradient projection method was upgraded using the algorithm of the route guidance method of the aircraft.

Usage of natural balance mode in automatic trajectory control of aircraft with non-standard configurations

Currently, especially with the development of unmanned aircraft, a lot of aerial vehicles are being developed, the layout of which differs from traditional ones. These include flying wing aircrafts, multi-rotor vehicles with symmetry breaking, carrying loads, especially on flexible hitch, ekranoplans and ekranolyot, winged missiles with an asymmetric arrangement of bearing and control surfaces, and others. When developing control systems, it is necessary to take into account that atypical schemes introduce effects into the flight dynamics of such aerial vehicles that complicate and even prevent the use of conventional simplifying schemes for them: dividing into control channels, dividing the control system into trajectory control and stabilizing angular motion, using linearized models.The paper proposes to ensure the coarseness of the system by refusing to solve intermediate problems and providing movement to the natural balancing modes. Moreover, in the structures under consideration, for feedbacks, precisely those measurements are used (overloads, angular velocities), which even with the simplest sensors give relatively small or relatively easily eliminated errors. Worse with measurement errors used for constraints (angles, heights). Here you will either have to narrow the boundaries or enter different settings of the control signals depending on the ratio of proximity to the borders and estimates of the measurement error, using, for example, fuzzy logic.

Aircraft Trajectory Control at the Motion on the Predetermined Route Based on the Global Navigation Satellite System

An algorithm to control the aircraft trajectory is proposed. This algorithm is based on the dynamic stochastic systems optimal control theory. The optimal control implementation is shown to reduce the deviation of the controlled trajectory from the predetermined one. The optimal control is based on estimating phase coordinates with the high accuracy by the global navigation satellite system.

Aircraft fault-tolerant trajectory control using Incremental Nonlinear Dynamic Inversion

This paper deals with aircraft trajectory control in the presence of model uncertainties and actuator faults. Existing approaches, such as adaptive backstepping and nonlinear dynamic inversion with online model identification, can be applied. However, since there are a number of unknown aerodynamic derivatives, the tuning of parameter update law gains is time-consuming. Methods with online model identification require excitation and the selection of a threshold. Furthermore, to deal with highly nonlinear aircraft dynamics, the aerodynamic model structure needs to be designed. In this paper, a novel aircraft trajectory controller, which uses the Incremental Nonlinear Dynamic Inversion, is proposed to achieve fault-tolerant trajectory control. The detailed control law design of four loops is presented. The idea is to design the loops with uncertainties using the incremental approach. The tuning of the approach is straightforward and there is no requirement for excitation and selection of a threshold. The performance of the proposed controller is compared with existing approaches using three scenarios. The results show that the proposed trajectory controller can follow the reference even when there are model uncertainties and actuator faults.

Comparison of Stochastic Methods for Control in Air Traffic Management

AbstractThis paper provides a direct comparison of two stochastic optimisation techniques (Markov Chain Monte Carlo and Sequential Monte Carlo) when applied to the problem of conflict resolution and aircraft trajectory control in air traffic management. The two methods are then also compared to another existing technique of Mixed-Integer Linear Programming which is also popular in distributed control.

Sliding electric arc discharge as a means of aircraft trajectory control

The dynamics of sliding electric arc discharge and the formation of shock waves in the stages of leader motion and the electric arc development in a supersonic air flow behind the shock wave have been studied for an initial pressure of 0.09–0.5 atm (bar). The air flow in the discharge was imaged using an optical system comprising a shadow device (IAB-458), an optical interference attachment (RP-452), and a modified ruby laser (OGM-20) producing 10–15 output pulses per pumping pulse. Stable initiation of sliding electric arc discharge takes place in a supersonic air flow behind the shock waves with 1.7<M<3.4. This discharge produces shock waves leading to separation of the boundary layer and to an increase in the pressure at the surface. These shock waves can be used for modifying gasdynamics in the air flow streamlining the surface and for controlling the motion of an aircraft.

Nonlinear adaptive and sliding mode flight path control of F/A-18 model

The question of inertial trajectory control of aircraft in the three-dimensional space is discussed. It is assumed that the nonlinear aircraft model has uncertain aerodynamic derivatives. The control system is decomposed into a variable structure outer loop and an adaptive inner loop. The outer-loop feedback control system accomplishes (x,y,z) position trajectory and sideslip angle control using the derivative of thrust and three angular velocity components (p,q,r) as virtual control inputs. Then an adaptive inner feedback loop is designed, which produces the desired angular rotations of aircraft using aileron, elevator, and rudder control surfaces to complete the maneuver. Simplification in the inner-loop design is obtained based on a two-time scale (singular perturbation) design approach by ignoring the derivative of the virtual angular velocity vector, which is a function of slow variables. These results are applied to a simplified F/A-18 model. Simulation results are presented which show that in the closed-loop system asymptotic trajectory control is accomplished in spite of uncertainties in the model at different flight conditions.

On-line Trajectory Control of Aircraft Using Neural Networks

In this paper an artificial Neural Network (NN) is used to control an aircraft along a predetermined trajectory. The inverse dynamics concept is used. Two NN models are used: one for forward identification NNI) nd he ther ne or nverse odel identification and forward control (NNC). After training of both models the NNC is used as a forward controller to the aircraft model. The simulation results shows good agreement between required and achieved trajectory.

I-O map inversion, zero dynamics and flight control

The trajectory control of aircraft in rapid, nonlinear maneuvers is discussed. Based on nonlinear invertibility theory, a control law is derived to independently control roll, pitch, and sideslip angles using rudder, elevator, and aileron. Integral feedback is introduced in order to obtain robustness in the control system to parameter uncertainty. The stability of the zero dynamics is examined. Simulation results are presented to show that in a closed-loop system, precise simultaneous lateral and longitudinal maneuvers can be performed despite the presence of uncertainty in the stability derivatives.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>