Control Of Aerospace Vehicles Research Articles

Review on guidance and control of aerospace vehicles: recent progress and prospect

Review on guidance and control of aerospace vehicles: recent progress and prospect

Fluidic Thrust Vector Control of Aerospace Vehicles: State-of-the-Art Review and Future Prospects

Abstract An efficient propulsion system holds the key to the smooth operation of any aerospace vehicle over different flight regimes. Apart from generating the necessary thrust, emphasis has also been laid on vectoring the direction of thrust. The primitive modes of thrust vectoring chiefly focused on mechanical means such as the use of gimbals or hinges. The current state-of-the-art technologies demand more efficient methods for thrust vectoring, which minimize the use of mechanical components. These methods termed fluidic thrust vector control methods, employ secondary jets for achieving the required attitude, and trajectory of the aerospace vehicles such as aircraft, rockets, and missiles. Such methods have greatly helped in reducing vehicle weight, vehicle maintenance requirements, and enhancement of stealth characteristics of such vehicles. This work presents a review of the various fluidic thrust vectoring systems, starting with a brief overview of traditional thrust vectoring systems, followed by a discussion on the various aspects of fluidic thrust vectoring systems. It also highlights the effect of the various geometrical and operating conditions on the performance parameters of the thrust vectoring system such as the thrust vector angle, system thrust ratio, and thrust vectoring efficiency among others. For ensuring the comprehensive character of this work, synthetic jet vectoring techniques have also been included due to their nonmechanical nature and similarities with purely fluidic thrust vectoring techniques.

Advanced Control Strategies for Rotary Double Inverted Pendulum

This paper presents the stabilization control of the rotational double inverted pendulum system. It is generally a non-linear, non-minimum phase, unstable, and underactuated system of high order. It has some significant real-life applications such as position control, aerospace vehicle control, and robotics. The objective is to determine the control law to the motor’s output torque such that the inverted pendulum motion will be stabilized about a vertical axis and position the rotary arm to a commanded angular position. In this study, multi-PID controllers, Linear-Quadratic Regulator (LQR), and Internal Model Control (IMC) controllers are designed and MATLAB-based simulations are performed to understand and compare the performance of the three control schemes.

Systematic fuzzy Navier–Stokes equations for aerospace vehicles

PurposeTo prove the effectiveness of the proposed design method, this study aims to propose the Fisher equation and temperature cooling fins that control high-speed aerospace vehicles.Design/methodology/approachA new approach whereby the control of aerospace vehicles can be achieved by fuzzy controller and appropriate Navier–Stokes equations in this article. The design of the controller based on models of Navier–Stokes equations simplified complex mathematical simulations and approximations.FindingsIf the fuzzy controller cannot stabilize the system, the Navier–Stokes fuzzy function is injected into the system as a controller tool, and the system is asymptotically stabilized by adjusting the fuzzy parameters.Originality/valueThe simulation results show that if the tuning frequency is high enough, the fuzzy controller and fuzzy observer can create chaotic movements by adjusting the dither amplitude appropriately. The demonstration of the Fisher equation and the temperature-cooled fin control problem for high-speed aerospace vehicles has displayed the benefits of combining fuzzy control with the Navier–Stokes equation.

The aerospace vehicle control characterizing by considerable time delay

In this paper, we propose to compensate the time delay in the vehicle response by a display that demonstrates the vector of predictive velocity projected on the surface located on a preliminary defined distance from the operator’s eyes. The effectiveness of the approach is demonstrated for the tasks of lunar rover docking and control.

Special issue on advanced control of aerospace vehicles

Special issue on advanced control of aerospace vehicles

Intelligent Constrained Optimal Control of Aerospace Vehicles with Model Uncertainties

Approximate dynamic programming formulation implemented with an “adaptive critic-based” neural network structure has been shown to be a powerful technique to solve theHamilton–Jacobi–Bellman equations. As interest in this technique grows, it is important to consider the enabling factors for their possible implementations. A typical adaptive critic structure consists of two interacting neural networks; in this paper, a new architecture, called the “cost function-based single network adaptive critic” is presented that eliminates one of the networks. This approach is applicable to a wide class of nonlinear systems in engineering where the optimal control equation can be explicitly expressed in terms of the state and cost-related variables. After the “training,” the output of the neural network represents the optimal cost. Optimal control is obtained by finding the derivatives of the output of the network with respect to its input and using it in the expression for optimal control. In practical applications, there usually exist uncertainties in modeling and in system parameters. Furthermore, the controllers have operational limits. The first concern is taken care of through an “approximated system” that contains an estimate of the uncertainties from an online neural network andhelps calculate the optimal control for the changed plant. Regarding the second concern, a nonquadratic term that incorporates the control constraints is used in the performance index. Necessary conditions for optimal control are derived and an algorithm to solve the constrained-control problem with cost function-based single network adaptive critic is developed. Two aerospace systems are used to illustrate the working of the proposed technique.

Stabilization of relative equilibria for underactuated systems on Riemannian manifolds

This paper describes a systematic procedure to exponentially stabilize relative equilibria of mechanical systems. We review the notion of relative equilibria and their stability in a Riemannian geometry context. Potential shaping and damping control are employed to obtain full exponential stabilization of the desired trajectory. Two necessary conditions are that the effective potential be positive definite over a specified subspace and that the system be linearly controllable. Relevant applications to underwater and aerospace vehicle control are described.

Concise encyclopedia of aeronautics & space systems

Active control for segmented mirror optical systems. Active control technology. Active control technology: general aspects. Aerospace systems and control. Air traffic control systems. Air traffic control: trends. Air traffic management and aircraft guidance in and around a main terminal. Airships: guidance and control. Angle of attack. Artificial control load (artificial feel spring). Artificial intelligence: impact. Attitude control. Automatic control: impact. Civil aircraft: long-term future. Cockpits: impact of new technology. Combat aircraft: long-term future. Communication in space: telemetry and data processing. Computer security systems: possibility theory. Control-configured vehicles. Control in aerospace systems. Data links in aerospace systems. Detection of sensor failure. Digital communication for satellites. Dynamics of aircraft and basic autopilots. Engine control: general aspects. Engine control: physical principles. Engine control: system design. Flexibility of aerospace vehicles. Flexible spacecraft: computer-oriented control analysis. Flight control: autopilot modes. Flight control: autopilots. Flight control systems, automatic. Flight envelope. Flight management systems. Flight simulation systems and simulators: an introduction. Flight simulation systems and simulators: techniques. Fly-by-wire systems. Fuel conservation in air transport. Full-authority control of aerospace vehicles. Head-up displays and trajectory control. Helicopters. Helicopters: flight control assistance. Helicopters: long-term future. Helicopters: turbine-engine governing systems. Homing of aerospace vehicles. Inertial navigation systems. Inertial navigation systems: selection. Instrumentation: development of cathode ray tube technology. Landing approach guidance: automatic landing in bad weather conditions. Landing approach guidance: automatic landing systems. Landing approach guidance using differential global positioning system. Linear quadratic Gaussian multivariable control designs: robustness. Manufacturing, automated. Measurement of speed and acceleration. Meteorological measurement techniques. Missiles: guidance and control. Modellization approach. Multitimescale systems. Navigation, four-dimensional. Navigation in space. Remote sensing: long-range wind velocity determination. Remote sensing: removal of atmospheric effects. Remote sensing satellites. Rigid spacecraft: attitude control. Robots: control in space applications. Robots: use in the aerospace industry. Satellites: adaptive control. Satellites, drag-free. Satellites: monitoring. Satellites: solar power. Shuttle control during approach. Shuttle control systems: reliability. Simulation. Singular perturbations: boundary-layer problem. Space and deep space environment. Space and earth reference systems. Space launchers, multistage. Space launchers: problems. Space vehicle launches: meteorological constraints. Space vehicle trajectories: optimization. State equations: singular perturbations. Supersonic and hypersonic flight: impact on air transport system. Traffic simulators: human aspects and aircraft realism. Training simulators: cost efficiency. Training simulators, real-time. Visual flying rules and instrument flying rules. Visual flying rules and instrument flying rules: general aspects. Wing load alleviation. Wing load alleviation: modelling. Workload for operators in complex person-machine systems. 300 illus. approx. including line drawings, 1500 lit. refs. approx.

Adaptable method of managing jets and aerosurfaces for aerospace vehicle control

An actuator selection procedure is presented that uses linear programming to optimally specify bounded aerosurface deflections and jet firings in response to differential torque and/or force commands. This method creates a highly adaptable interface to vehicle control logic by automatically providing intrinsic actuator decoupling, dynamic response to actuator reconfiguration, dynamic upper bound and objective specification, and the capability of coordinating hybrid operation with dissimilar actuators. The objective function minimized by the linear programming algorithm is adapted to realize several goals, i.e., discourage large aerosurface deflections, encourage the use of certain aerosurfaces (speedbrake, body flap) as a function of vehicle state, minimize drag, contribute to translational control, and adjust the balance between jet firings and aerosurface activity during hybrid operation. A vehicle model adapted from Space Shuttle aerodynamic data is employed in simulation examples that drive the actuator selection with a six-axis vehicle controller tracking a scheduled re-entry trajectory.

Sparse Jacobian updates in the collocation method for optimal control problems

Advanced guidance algorithms for the control of aerospace vehicles can require rapid solution of an optimal control problem. The necessary conditions for the solution of an optimal control problem result in a two-point boundary-value problem. For guidance applications, the boundary-value problem must be solved rapidly in order to reflect real-time navigation input. The collocation method has been proposed by a number of authors as a robust approach to the problem. By introducing piecewise cubic polynomial interpolation of the dynamic variables, the boundary-value problem is reduced to solving a system of nonlinear algebraic equations, the resulting iteration equation involves a large sparse matrix. This paper demonstrates the application of sparse Broyden updates for the iteration matrix that results in significant time savings. The viability of the approach for real-time optimal control applications is illustrated with computational results for maximum downrange and crossrange Shuttle re-entry trajectories and for simpler powered flight ascent trajectories. A substantial reduction in computation cost has been observed for typical cases.

Initial Condition Sensitivity Functions and Their Applications

The well-known method of obtaining sensitivity functions is usually restricted by the condition of continuity imposed on the functions of the coordinates in system equations. For the case of discontinuous functions, more elaborate procedures are required to give a good linear approximation. It is shown that sensitivity functions are discontinuous at the discontinuous points. Also, relations between elements of sensitivity functions at these points are shown to be linear for a given nominal solution of the system. The switching time of the desired Bang-Bang control can be estimated if variations in initial conditions are known. The changes in terminal states and cost function due to deviations in initial conditions can be determined, to first order, by the use of sensitivity functions. Bounds on the deviations in initial conditions can be found by a worst case approach so that the desired terminal conditions are satisfied within given tolerances. The fundamental importance of these techniques in a number of areas of application, for instance, guidance and control of aerospace vehicles, is well known.

Adaptive control applications to aerospace vehicles

HE word is used to describe the capability of human beings, animals, and plant life to adjust their characteristics in accordance with a changing environment. The adaptive control system thus is a system which will adjust its own characteristics in order to provide a desired control system performance in a changing dynamic environment. There has been considerable literature published on the subject of adaptive automatic control systems which has been concerned with aerospace vehicle control, process control, and machine control, as well as control in other technical areas. Research has included very general investigations which could apply to automatic controls of all types, as well as specific investigations concerned with the development of systems designed to adapt to particular environmental changes and for a particular application. The present survey is of the latter type, and is concerned with adaptive control systems which adapt for changing dynamics of the aerospace vehicle, when the vehicle is considered as a rigid body. Vehicle aerodynamic characteristics are changing due to changes in vehicle configuration, flight speed, Mach number, and altitude. These changes result in changes in the dynamics of the aerospace vehicle. The research approach used in the current survey was to perform search of patents granted in the United States on adaptive control systems. This search located 45 patents which were granted between the years of 1925 and 1967. Of these 45 patients, only 26 were determined to be within the scope of this paper. In addition to the patented systems, four systems of interest were located from a survey of current papers on adaptive flight control systems. The objective of the survey was to investigate the requirements for adaptive control systems, and to determine the means which have been developed to implement these requirements. The techniques discussed are generally applicable for use on all three axes of the aerospace vehicle. However, the examples presented are with reference to the pitch axis.

Guidance and control of aerospace vehicles

Guidance and control of aerospace vehicles

Guidance and Control of Aerospace Vehicles. Edited by C. T. Leondes. McGraw Hill Book Co., London. 1963. 610 pp. Diagrams. £7 11s. 0d.

An abstract is not available for this content so a preview has been provided. Please use the Get access link above for information on how to access this content.

Star Tracking and Scanning Systems their Performance and Parametric Design

This paper deals with star tracking and scanning systems whose ultimate application is the navigation and control of aerospace vehicles. The subject generally has received very sparse treatment in the open literature. It will be the purpose of this paper to discuss some of the critical considerations related to the optimum design and performance of star trackers and scanners. It discusses the basic system and its functional elements, the input data, its character and limitations, the optical system, its characteristics and performance, the photomultiplier and vidicon as promising radiation detectors, the decision problem and its probabilistic nature, and the optimization of system performance through the manipulation of major design parameters.