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Military and civil aviation are requiring higher performance for the aircrafts in recent years. The morphing techniques can effectively improve aircraft's performance to meet the customer's multi-mission requirement for the aircraft. To get the optimal aerodynamic performance under different flight conditions, the aircraft must change its aerodynamic configuration adaptive to specific condition. In...
A direct method is discussed for multistage launch vehicle ascent trajectory optimization. First the optimal control problem is modeled with the performance index as maximum terminal mass. A modified Gauss Pseudospectral method is used to design a rapid optimal algorithm for multistage launch vehicle ascent trajectory. The nonlinear terminal state constraints are converted into linear terminal state...
In this work, the authors consider the applications of sliding mode controllers to the longitudinal flight dynamics of the benchmark system of scaled Yak-54 Unmanned Aerial Vehicle for executing maneuvers over full flight envelope. Control of unmanned aerial vehicle involves the problem of incomplete measurements, modeling uncertainties and external disturbances. Sliding mode control provides good...
Characteristic modeling based all coefficients adaptive control was proposed by Academician Wu Hong-Xin in 1980s. The theory is motivated and gradually enhanced to completion in the past three decades. This theory and method have already been applied successfully to the reentry adaptive control of manned spaceships, automatic rendezvous and docking between Shenzhou-8, Shenzhou-9 and Tiangong-1, etc...
In this paper, we consider the control problem of the hypersonic flight vehicle analogy X20. Through a careful analysis of the relationship between the aerodynamic coefficients and their independent variables of height, Mach number, attack angle, sideslip angle and rudder angel, we fit the aerodynamic coefficients according to the independent variables and give their analytic expressions. And we establish...
This paper focuses on the adaptive tracking problem for air-breathing hypersonic vehicles (AHVs) subject to aerodynamic uncertainties and unknown disturbances caused by modeling errors. Motivated by the nonlinear disturbance observer-based control approach (NDOBC), the parameter uncertainties are merged into the disturbances. A control law based on the tracking control method originally proposed by...
This paper reviews research results on flight control of air-breathing hypersonic cruise vehicles. The results are classified according to different flight control strategies. Their main ideas and drawbacks are analyzed. Finally, some suggestions on future work based on the analysis are pointed out.
According to the flight path planning problem in dynamic environment, this paper gives a method of analysis. First, the radar threat field based on Voronoi diagram is created, and the track performance indicators established based on radar threat cost and fuel cost. Then the dijkstra algorithm was improved, and the algorithm is used for path planning in dynamic environment‥ Finally, the simulation...
A mathematical model of an injector powered transonic wind tunnel is developed in this paper. The whole running process is divided into three stages and the model of each child processes is established respectively. The data applied to the parameter identification is obtained from the actual running process. The NARMAX model is adopted as the structure of model and the parameters including the order...
For the nonlinear coupling control problem induced by the maneuver flying with high angle of attack of the hypersonic vehicle, the dynamic inversion is used to realize the decoupling of the attack angle and bank angle dynamics. For the model uncertainty, parameter perturbation and outer disturbance, the estimation and compensation of the disturbance moments is carried out by the extended state observer...
This paper presents the method of aerodynamic optimization utilizing control theory, which is also called the adjoint method. The discrete adjoint equations are obtained from an unstructured cell-vortex finite-volume Navier-Stokes solver. The developed adjoint equations solver is verified by comparison of objective sensitivities with finite differences. An aerodynamic optimization system is developed...
The 2.4m×2.4m wind tunnel is a system with the properties of strong nonlinear, multiple variables, serious coupling, large lagging, time-varying, etc. The complexity of all these phenomena makes the development of suitable dynamic Mach number models based on the aerodynamics laws very difficult. As an alternative, the Ensemble Neural Networks (ENN) model based on the feature subsets is proposed to...
This communication considers the case in which some aerodynamic actuator failures occur when an aircraft performs the intended maneuver. The problem considered deals with online reassignment of the remaining effective actuators to continue performing the current maneuver safely. First, through analysis of a general nonlinear system, the concept of virtual inputs and fault tolerance is proposed and...
In this paper, an adaptive output feedback controller was developed for a class of nonlinear systems with unkonwn parameters, uncertain disturbances and unmeasured states. Firstly estimated states was obtained by introducing an observer. Then a controller was developed based on the dynamic surface control approach. Explosion of terms can be avoided because this method no longer needs the repeated...
In this study, a neural network (NN) based dynamic Mach number predictive control was proposed for a wind tunnel Match number control system. The proposed method absorbed in advantages both artificial neural network and model predictive control, for control of strong nonlinear, multiple variables, large lagging, and time-varying system. In this approach, the dynamic of wind tunnel is represented by...
Military and civil aviation are requiring higher performance for the aircrafts in recent years. The Morphing techniques can effectively improve aircraft's performance to meet the customer's multi-role requirement for the aircraft. The physical model of a variable-span and variable-sweep morphing aircraft is simplified. Based on the Kane's method, the morphing motions are assumed to be controllable...
In this paper, the design of simulation software and control system for unmanned aerial vehicle (UAV) during aerial refueling is proposed, in which the simulation software is constructed under Microsoft Visual Studio 2010, and control system is designed based on the linear control theory and assumption of relatively small perturbations during the docking. The proposed model has the merits of explicitly...
For the power plant of hypersonic vehicle - scramjet, this work mainly studies the effects of the translating cowl of inlet on the static and dynamic performance of the hypersonic vehicle. The results indicate that the effects of the cowl on lift and drag can be negligible, while the effects of the cowl on thrust and pitching moment are significant. The cowl makes thrust-drag ratio bigger and the...
The ultra-low orbit satellites generally orbit at an altitude about 200km, and have better performance of observing the Earth and receiving information while using the same observation instrument, thus have good economic benefits and broad application prospects. However, the aerodynamic forces and moments interference to the ultra-low-orbit satellites are dozens of orders of magnitude higher than...
The design of a flight controller not only stabilizes attitude angle, but also tracks a trajectory accurately. For a quadrotor unmanned aerial vehicle (UAV) in presence of parametric uncertainties and external disturbances is more challenging. A hybrid control method based on backstepping and fuzzy adaptive PID is proposed, which improves the flight stability of quadrotor aircraft in different conditions...
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