Angle Of Attack Control Research Articles

Adaptive tracking guidance for powered aeroassisted orbital maneuver under system uncertainties and input constraints

The powered aeroassisted orbital maneuver (AOM) is an emerging type of AOM manner, which can fulfill various complicated orbital transfer missions more flexibly and efficiently by virtue of aerodynamic forces and synergetic thrust. In this paper, an adaptive control strategy is presented for the reference trajectory tracking guidance of powered AOM under system uncertainties and input constraints. The presented controller is designed with an attack angle control law and a bank angle control law. The constrained control inputs are smoothly described through a hyperbolic tangent-type function. Then, the attack angle and bank angle control laws are separately developed by utilizing the first-order and second-order backstepping control methods. Besides, the parametric adaptive mechanism is incorporated to identify the squares of the upper bounds of the total uncertain items. Benefiting from this design, the presented controller can not only resist system uncertainties, but also accommodate input constraints. The stability evaluation shows that the radial distance and velocity tracking errors under the presented controller can eventually stabilize to the bounded minor fields around zero. Lastly, the derived results are verified through comparative studies with an existing controller and Monte Carlo simulations under different conditions.

A LabVIEW Based Optimization and Integration of Supersonic Wind Tunnel Instrumentation System

Indonesian National Institute of Aeronautics and Space have a supersonic wind tunnel for research in high speed object . The condition of LAPAN's supersonic wind tunnel can only be used for shockwave observation by using schlieren apparatus. The data acquisition system can not collect data from sting balance, some of the control panels are either not operational or it need calibration. Based from these conditions, this research is done to develop a new integrated control system and data acquisition so that the effectiveness of operation in terms of time and better data quality can be achieved. For angle of attack (AoA) control from manual operation, have been optimized to a digital control using PID control method. With the new system, the AoA control has been automated and a new testing option for moving the AoA while the wind tunnel running can be done. In terms of data acquisition, after the optimization it can collect better data, (noise / interference becomes smaller), and now it can record data from the balance, the pressure data, AoA position and block position can be recorded. The system was created using PXIe from National Instrument and LabVIEW graphical programming as user interface.

A LabVIEW Based Optimization and Integration of Supersonic Wind Tunnel Instrumentation System

Indonesian National Institute of Aeronautics and Space have a supersonic wind tunnel for research in high speed object . The condition of LAPAN's supersonic wind tunnel can only be used for shockwave observation by using schlieren apparatus. The data acquisition system can not collect data from sting balance, some of the control panels are either not operational or it need calibration. Based from these conditions, this research is done to develop a new integrated control system and data acquisition so that the effectiveness of operation in terms of time and better data quality can be achieved. For angle of attack (AoA) control from manual operation, have been optimized to a digital control using PID control method. With the new system, the AoA control has been automated and a new testing option for moving the AoA while the wind tunnel running can be done. In terms of data acquisition, after the optimization it can collect better data, (noise / interference becomes smaller), and now it can record data from the balance, the pressure data, AoA position and block position can be recorded. The system was created using PXIe from National Instrument and LabVIEW graphical programming as user interface.

Power Model of a Small Wind Plant

The production of small wind turbines requires constant modification of their designes. One of the main criteria for efficiency is the power of the wind farm. It makes it possible to evaluate the economic effect in simple categories and by simple means. (Research purpose) The research purpose is to develop a simplified scheme for estimating power flows in a wind farm to assess its main technical and economic indicators. (Materials and methods) The article describes the main operating modes of small wind power plant and correlates them with wind speeds. A small wind turbine with a capacity of 1.8 kilowatt with attack angle control with a nominal wind speed of 8 meters per second was used as the initial sample for testing. The dependence of the power of an operating small wind farm on the wind speed are presented in the article and was used for creating a mathematical model. (Results and discussion) It has been suggested that the efficiency at the nominal wind speed is maximum, but at the starting wind speed it is close to zero. The article presents a power model, the total power output of the installation, the static power loss dynamic power loss of power and aerodynamic limitations. In this case, the power of dynamic losses depends on the overall efficiency of the wind turbine, which is a function of the wind speed. The article presents graphical representation of these power flows. (Conclusions) The theoretical dependence of wind turbine capacity flows is a simple way to determine them in an existing wind turbine. The main characteristics of the model can be calculated from the dependence of power on wind speed, which significantly expands the possibilities of its application for further research. The model can be used in evaluating the effectiveness of the designed structure or changes in it.

Guidance Law Design with Attack Angle Control and Maneuvering Avoidance

In order to realize the tactical task of anti-ship missile attacking target in the predetermined direction, and improve its penetration effect under the condition of enemy ship-to-air missile interception, a guidance law with attack angle control and maneuvering avoidance is designed. Using the terminal sliding mode theory, based on the relative motion model between missile and target, the guidance law defined a sliding surface, which includes miss distance requirement, terminal angle constraint and terminal maneuvering information. The guidance law can attack the target in the predetermined direction and realize its own trajectory maneuvering penetration. The simulation results verify the validity of the designed method.

Experimental study of the method of locomotive wheel­rail angle of attack control using acoustic emission

The methods for determining the locomotive wheel-rail angle of attack are considered. To reduce the power impact of the wheel flange with the rail head when the locomotive moves on curved sections of the track, it is advisable to change the locomotive wheel-rail angle of attack by turning the wheel pairs. Controlling the locomotive wheel pair position is possible by means of an operational measurement of the actual wheel-rail angle of attack. Measurement of the wheel-rail angle of attack is not performed because it is impossible to determine the value directly.It is proposed to measure the locomotive wheel-rail angle of attack when the wheel pair moves in the rail track on the basis of the method of acoustic emission resulting from the wheel-rail contact interaction. An information measuring system has been developed for the determination and analysis of acoustic emission from the wheel-rail contact consisting of: a stand roller magnet, a speed sensor, a directional microphone, an analog-digital card, a sound level meter. The obtained experimental data of acoustic emission from the contact of the roller stand wheel with the roller during motion are analyzed. The dependence of the acoustic emission of the locomotive wheel-rail contact interaction on the values of the maximum deviation of the sound pressure level from the equivalent level in the frequency range 200...300 Hz is revealed.The obtained analytical dependence of the maximum deviation of the sound pressure level from the equivalent at different values of wheel-rail angles of attack can be used to create an automatic control system of the wheel pair position in the rail track.

回転跳躍ロコモーションを行なうハンドスプリングロボットの制御

The continuous motion composed of rolling and jumping such as continuous handspring is useful as the locomotion of robots. In order to realize the continuous handspring, we propose a multi-link robot model composed of two limbs and a body and the control law for the model. We verified the controller using the combination of attack angle control and the control based on the angular momentum of the robot in the simulation. In the verification, the robot model realized 100,000 steps in the continuous handspring in the certain environment. In addition, it realized 20 steps after the temporary change of coefficient of static friction of the floor from infinity to four and over in the verification of the robustness against the temporary disturbance.

局地気象計測のための安全な係留気球の開発に関する研究

Captive balloon is sometimes used for weather observation. But at the time of strong wind, the stability of the balloon is reduced, and various risks of balloon (disconnection, collision of buildings, fall of measuring equipment) are increased. Therefore, we aim to develop of safe captive balloon against the wind force. In order to that, we perform four of change. Firstly, we provide an angle of attack to the balloon. Secondly, we provide a tail and introduce ACS (Attack Angle Control) system. Thirdly, the way to keep the balloon is changed from Kapton to net. Finally, the introduction of the tension control device. The result of the change, stability and safety of the balloon improves.

Research on Aircraft Attack Angle Control Considering Servo-Loop Dynamics

This paper presents a novel robust attack angle control approach, which can effectively suppress the impacts from system uncertainties and servo-loop dynamics. A second-order linear model of electromechanical servo loop is considered in the modeling and design processes. With regard to the block-structure models facing attack angle control, the multiple robust surfaces and dynamic surface control (DSC) approaches are both employed. By means of Lyapunov function method, the stability conditions of attack angle control systems are, respectively, given without/with considering the servo-loop dynamics in design process. Computer simulation results present that, compared with the attack angle control scheme which does not consider the servo-loop dynamics in design process, the proposed scheme can guarantee that the whole attack angle control system possesses the better comprehensive performances. Moreover, it is easy to be realized in engineering application.

A Variable Structure Attitude Control System Design Based on Finite Time Stability

A variable structure attitude control system design method that guarantees the finite-time stability is proposed for hypersonic vehicle attitude control. According to the characteristics of the hypersonic vehicle longitudinal attitude model, it is considered to comprise attack angle control loop and angular rate control loop. The attack angle controller and pitch angular rate controller based on variable structure control are designed respectively which ensure the finite-time stability. The finite-time stability of the whole attitude control system has been proved .The simulation results illustrated that the proposed attitude controller has good rapidity and robustness.

Immersion- and invariance-based adaptive missile control using filtered signals

The article presents a new non-certainty-equivalent adaptive (NCEA) longitudinal autopilot for the control of a missile based on the immersion and invariance theory. The interest here is to control the angle of attack of the missile in the presence of large parametric uncertainties. For the derivation of the control law, a backstepping design procedure is used. At each step of the design, certain filtered signals are generated for the synthesis of a stabilizing control signal and a parameter estimator. Using Lyapunov stability analysis, it is shown that in the closed-loop system, trajectory control of the angle of attack is accomplished, and the trajectories of the system are attracted to certain manifold in the space of state variables and parameter errors. For stability in the closed-loop system, an explicit analytical relation involving the controller gains is obtained. It may be pointed out that recently an adaptive autopilot based on the immersion and inversion theory has been designed, but it has stringent requirements because for its synthesis, the derivatives of the Mach number and angle of attack must be known, and a large number of parameters must be updated. The derived control system of this article is synthesized using only the state variables, and its identifier is of lower order. A traditional certainty-equivalent adaptive autopilot is also presented for comparison. Simulation results are obtained which show that the designed NCEA control system can accomplish angle of attack control despite large parametric uncertainties; and it can give better tracking performance than the traditional controller.

Control strategy for maximizing reconnaissance range of hypersonic cruise vehicles

Advances in hypersonic vehicle technologies, including high-temperature materials, lightweight structures, and high thrust-to-weight ratio engines, indicate that a strategic vehicle at higher Mach numbers (approximately 6) is feasible. An efficient performance analysis method is developed along with a control strategy to evaluate potential hydrogen-fueled turbojet/ramjet propulsion systems for advanced technology hypersonic cruise vehicles. A conceptual strategic reconnaissance mission is evaluated for tradeoffs between throttle and angle of attack control in minimizing fuel consumption/maximizing range. Many mission, flight, and vehicle-related requirements and constraints are satisfied in the design process. In addition, powered hypersonic flight produces unique performance characteristics not encountered at subsonic speeds.

A computational method for free time optimal control problems, with application to maximizing the range of an aircraft-like projectile

AbstractA class of non-standard optimal control problems is considered. The non-standard feature of these optimal control problems is that they are of neither fixed final time nor of fixed final state. A method of solution is devised which employs a computational algorithm based on control parametrization techniques. The method is applied to the problem of maximizing the range of an aircraft-like gliding projectile with angle of attack control.

Comment on "Ram Wing Surface Effect Boat"

vides of incidence control. I feel that the words between quotation marks cannot possibly express the authors' real views. As far as I can judge, Bras d'Or's incidence is under complete control. All that these words do is belittle G's role in Bras d'Or's operation. The whole article tends to convey the impression that Bras d'Or functions on the surface piercing principle, augmented by something unnamed, which on analysis appears to be G's angle of attack control. No data are furnished to show in what measure the two principles actually divide between themselves the task of controlling lift. That would be inconsequential if Bras d'Or were presented as a hybrid configuration. But under the circumstances, there is a need for more precise data. One is reduced to conjectures. I have reasons to believe that Grunberg's contribution to lift control is not secondary at all, and I would not be surprised if variable angle of attack were the senior partner in its association with area variations. 5) Having covered my own case, I feel the responsibility to add a few words on behalf of those whose voices are stilled. The undisputed father of area control is Forlanini, but his was the ladder version. Crocco substituted surface piercing for the ladder. It would seem that research into the other (not-Grunberg) branch of Bras d'Or's family tree should have lead either to Forlanini, the distant progenitor, or, closer, to Crocco. Our admiration for the father of the telephone cannot be dimmed by the recognition that in hydrofoils Bell and Baldwin were only apostles of Forlanini's gospel. They visited Forlanini in Italy, studied his boat, purchased his patents. After several less successful models, thanks to sound engineering and with some improvements, by no means basic, they produced the excellent HD-4, of the ladder type. The HD-4 does not even appear to be in direct line of Bras d'Or's ancestry. I have sympathy for Forlanini and Crocco, who more than anyone else deserve to be remembered in their descendents of the surf ace-piercing type.