Rapid transfer alignment for SINS of carrier craft

In order to improve the survival ability and rapid response ability of the carrier craft,a new rapid transfer alignment method of the strapdown inertial navigation system（SINS） on a rocking base is put forward.In the method,the aircraft carrier does not need any form of movement.Meantime,interfering motions such as rolling,pitching,and yawing motions caused by sea waves are effectively used.Firstly,the deck flexure deformation model is made.Secondly,the state space model of transfer alignment is presented.Finally,the feasibility of this method is validated by the simulation.Simulation results show that the misalignment angle error can be estimated and reach an anticipated precision-0.2 mrad in 5 s,while the deck deformation angle error can be estimated and reach a better precision- 0.1 mrad in 20 s.

Optimal control based coordinated taxiing path planning and tracking for multiple carrier aircraft on flight deck

Coordinated taxiing planning for multiple aircraft on flight deck is of vital importance which can dramatically improve the dispatching efficiency.In this paper,first,the coordinated taxiing path planning problem is transformed into a centralized optimal control problem where collision-free conditions and mechanical limits are considered.Since the formulated optimal control problem is of large state space and highly nonlinear,an efficient hierarchical initialization technique based on the Dubins-curve method is proposed.Then,a model predictive controller is designed to track the obtained reference trajectory in the presence of initial state error and external disturbances.Numerical experiments demonstrate that the proposed“offline planningþonline tracking”framework can achieve efficient and robust coordinated taxiing planning and tracking even in the presence of initial state error and continuous external disturbances.

Determining the approach speed envelope of carrier aircraft

Many factors,such as deck motion and air wave,influence the determination of the approach speed which has an important effect on landing safety. Until recently,there are no design criteria about approach speed of carrier aircraft in the current standards and available publications. Therefore,the requirements of stall margin, longitudinal acceleration ability,altitude correction and field-of-view on approach speed were researched. Based on the flight dynamics model,the flight simulations were conducted to study the effect of the response time of engine,wave off requirements,elevator efficiency and deflection rate on the approach speed. The results presented that the approach longitudinal acceleration and altitude correction ability had crucial influence on the approach speed envelope of the aircraft. The limitations of the control requirements,field- of- view requirements and gear were also given through the simulation and analysis. Based on the above results,the approach speed envelope were determined.

Winning Probability Estimation Based on Improved Bradley-Terry Model and Bayesian Network for Aircraft Carrier Battle

To provide a decision-making aid for aircraft carrier battle,the winning probability estimation based on Bradley-Terry model and Bayesian network is presented. Firstly,the armed forces units of aircraft carrier are classified into three types,which are aircraft,ship and submarine. Then,the attack ability value and defense ability value for each type of armed forces are estimated by using BP neural network,whose training results of sample data are consistent with the estimation results. Next,compared the assessment values through an improved Bradley-Terry model and constructed a Bayesian network to do the global assessment,the winning probabilities of both combat sides are obtained. Finally,the winning probability estimation for a navy battle is given to illustrate the validity of the proposed scheme.

Path planning for taxi of carrier aircraft launching

Launching efficiency is an important index to measure the fighting capacity of an aircraft carrier. The study on path planning for taxi of carrier aircraft is of great significance for enhancing the launching efficiency. Considering the launching efficiency and the safety in operation of carrier aircraft launching and taking into account the carrier aircraft maneuver performance, deck environment and feature of mission, we proposed a conceptual model which contains the key elements of path planning for taxi of carrier aircraft. Subsequently, the objective function for the path planning problem and its mathematical model containing various constraints were established. With the A * search algorithm, a dynamic weight heuristic function was designed. According to the characteristic of path planning model for taxi of carrier aircraft, a simple and effective detection method was introduced. Finally, a feasible path for taxi of carrier aircraft, which meets the constraints, was presented. Taking the Nimitz-class aircraft carrier as an example, the paths for taxi of carrier aircraft launching from elevators to catapults were planned. Simulation results demonstrated the rationality of the model and the effectiveness of the algorithm.

Numerical simulation of RCS for carrier electronic warfare airplanes

This paper studies the radar cross section （RCS） of carrier electronic warfare airplanes. Under the typical naval operations section, the mathematical model of the radar wave＇s pitch angle incidence range analysis is established. Based on the CATIA software, considering dynamic deflec- tions of duck wing leading edge flaps, flaperons, horizontal tail, and rudder, as well as aircraft with air-to-air missile, anti-radiation missile, electronic jamming pod, and other weapons, the 3D models of carrier electronic warfare airplanes Model A and Model B with weapons were established. Based on the physical optics method and the equivalent electromagnetic flow method, by the use of the RCSAnsys software, the characteristics of carrier electronic warfare airplanes＇ RCS under steady and dynamic flights were simulated under the UHF, X, and S radar bands. This paper researches the detection probability of aircraft by radars under the condition of electronic warfare, and com- pletes the mathematical statistical analysis of the simulation results. The results show that： The Model A of carrier electronic warfare airplane is better than Model B on stealth performance and on discover probability by radar detection effectively.

A review on carrier aircraft dispatch path planning and control on deck

As an important part in sortie/recovery process,the dispatch of carrier aircraft not only affects the sortie/recovery efficiency and safety,but also has severe influence on the carrier's combat efficiency and the comprehensive support capability.Path planning is the key to improve the efficiency and safety during the dispatch process.The main purpose of this paper is to propose a comprehensive investigation of techniques and research progress for the carrier aircraft's dispatch path planning on the deck.Three different dispatch modes of carrier aircraft and the corresponding modeling technologies are investigated,and the aircraft's dispatch path planning techniques and algorithms have been classified into different classes.Moreover,their assumptions and drawbacks have been discussed for single aircraft and multiple aircraft.To make the research work more comprehensive,the corresponding tracking control methodologies are also discussed.Finally,due to the similarity of path planning problem between the carrier aircraft's dispatch and those in other fields,this paper provides an exploratory prospect of the knowledge or method learned from other fields.

Obstacle avoidance and path planning for carrier aircraft launching

Abstract Launching safety and efficiency are important indexes to measure the fighting capacity of carrier. The study on path planning for taxi of carrier aircraft launching under actual deck environ ment is of great significance. In actual deck scheduling, manual command is applied to taxi of carrier aircraft, which has negative effects on the safety of staff and carrier aircraft launching. In consideration of both the safety and efficiency of carrier aircraft launching, the key elements of the problem are abstracted based on the analysis of deck environment, carrier aircraft maneuver performance and task requirements. According to the problem description, the mathematical model is established including various constraints. The carrier aircraft and the obstacles are reasonably simplified as circle and polygons respectively. What＇s more, the proposed collision detection model reduces the calculations. Aimed at the features of model, the theory of model predictive control （MPC） is applied to the path search. Then a dynamic weight heuristic function is designed and a dynamic multistep optimization algorithm is proposed. Taking the Nimitz-class aircraft carrier as an example, the paths from parking place to catapult are planned, which indicate the rationality of the model and the effectiveness of the algorithm by comparing the planning results under different simulation environments. The main contribution of research is the establishment of obstacle avoidance and path planning model. In addition, it provides the solution of model and technological foundations for comprehensive command and real-time decision-making of the carrier aircraft.

Multi-body dynamic system simulation of carrier-based aircraft ski-jump takeoff

The flight safety is threatened by the special flight conditions and the low speed of carrier-based aircraft ski-jump takeoff. The aircraft carrier motion, aircraft dynamics, landing gears and wind field of sea state are comprehensively considered to dispose this multidiscipline intersection problem. According to the particular naval operating environment of the carrier-based aircraft ski-jump takeoff, the integrated dynamic simulation models of multi-body system are developed, which involves the movement entities of the carrier, the aircraft and the landing gears, and involves takeoff instruction, control system and the deck wind disturbance. Based on Matlab/Simulink environment, the multi-body system simulation is realized. The validity of the model and the rationality of the result are verified by an example simulation of carrier-based aircraft ski-jump takeoff. The simulation model and the software are suitable for the study of the multidiscipline intersection problems which are involved in the performance, flight quality and safety of carrier-based aircraft takeoff, the effects of landing gear loads, parameters of carrier deck, etc.

Design and verification of a transfer path optimization method

This paper studies the transfer path planning problem for safe transfer of an aircraft on the aircraft carrier flight deck under a poor visibility condition or at night.First,we analyze the transfer path planning problem for carrier-based aircraft on the flight deck,and define the objective to be optimized and the constraints to be met.Second,to solve this problem,the mathematical support models for the flight deck,carrier aircraft entity,entity extension,entity posture,entity conflict detection,and path smoothing are established,as they provide the necessary basis for transfer path planning of the aircraft on the aircraft carrier.Third,to enable automatic transfer path planning,we design a multi-habitat parallel chaos algorithm(called KCMPSO),and use it as the optimization method for transfer path planning.Finally,we take the Kuznetsov aircraft carrier as a verification example,and conduct simulations.The simulation results show that compared with particle swarm optimization,this method can solve the transfer path planning problem for an aircraft on the aircraft carrier flight deck better.