Helicopter Model Research Articles

Combined passive and active helicopter main rotor morphing for helicopter energy save

In this article, passive morphing and active morphing approaches are combined to save more helicopter flight control system (i.e., FCS) energy. For this purpose complex, physics-based, control-oriented nonlinear helicopter models are benefited. A specific variance-constrained control strategy, namely Output Variance-Constrained Control (i.e., OVC) is applied for helicopter FCS. Control energy savings using passive, active and combined morphing approaches are examined. Parameters of helicopter FCS and combined morphing helicopter design parameters are simultaneously optimized using a stochastic optimization method, namely simultaneous perturbation stochastic approximation (i.e., SPSA). To observe energy save, closed-loop analyses are done. Finally, robustness of combined morphing helicopter with respect to (w.r.t.) the modeling uncertainties is examined.

Phase plane tuning of fuzzy controller for 1 DoF helicopter model

The paper suggests a design procedure for fuzzy cascade control. The expert knowledge based tuning procedure is supported by investigation the phase plane of the reference tracking. The plant is a one degree of freedom helicopter model with highly non-linear dynamics in a hardware-in-the-loop arrangement. Starting from a common fuzzy-PI controller in the outer loop and classic PI-controller in the inner loop, the presented tuning procedure enables to obtain fuzzy-adaptive parameter settings of the inner-loop and a heuristic modified rule base in the outer loop. The developed control strategy proves to be very successful: both the settling times and overshoots have become well regulated.

Modified central force optimization (MCFO) algorithm for 3D UAV path planning

Path planning for the three-dimensional (3D) unmanned aerial vehicles (UAV) is a very important element of the whole UAV autonomous control system. In this paper, a modified central force optimization (MCFO) method is introduced to solve this complicated path-optimization problem for the rotary wing vertical take-off and landing (VTOL) aircraft. In the path planning process, the idea from the particle swarm optimization (PSO) algorithm and the mutation operator of the genetic algorithm (GA) are applied to improve the original CFO method. Furthermore, the convergence analysis of the whole MCFO method is established by the linear difference equation method. Then, in order to verify the effectiveness and practicality of this new path planning method, the path following process is put forward based on the six-degree-of-freedom quadrotor helicopter control system. At last, the comparison simulations among the six algorithms show that the trajectories produced by the whole MCFO method are more superior than the original CFO algorithm, the GA, the Firefly algorithm (FA), the PSO algorithm, the random search (RS) way and the other MCFO algorithm under the same conditions. What is more, the path following process results show that the path planning results are practical for the real dynamic model of the quadrotor helicopter.

Computational Fluid Dynamics Modeling of Helicopter Fuselage Drag

The aim of this paper is to present aerodynamic analyses of realistic fuselage configurations using computational fluid dynamics. A development model of the Ansat helicopter is employed. The model is tested at the subsonic wind tunnel of the Kazan National Research Technical University/Kazan Aviation Institute for a range of Reynolds numbers, pitch, and yaw angles. The computational fluid dynamics results were found to be in fair agreement with the test data and revealed flow separation at the rear of the fuselage. Once confidence in the computational fluid dynamics method was established, further modifications were introduced to the fuselage model to demonstrate drag reduction via small shape changes. The contribution to the overall drag from each fuselage part and the interference drag between the main fuselage components were also investigated.

A Reconfiguration Scheme for Quadrotor Helicopter via Simple Adaptive Control and Quantum Logic

A reconfiguration control scheme is proposed for a quadrotor helicopter with loss of control effectiveness via simple adaptive control and quantum logic. Some good control performances of the helicopter can be achieved by applying quadratic optimal control with scheduled stability degree when the system is in normal operation. A parallel feedforward compensator is introduced to fulfill the condition of positive realness, and thus, the simple adaptive controller can be utilized for the helicopter. Quantum logic is also applied to the quadrotor control system, which achieves the quantization of the disturbances patterns. A mathematical model of the quadrotor helicopter for application is obtained from its dynamic equations with pitch, roll, and yaw axes, which includes the parameter perturbation and outer disturbances. Several simulation and experimental results for the faulty helicopter validate the robustness and reconfiguration control capability of the proposed scheme.

An IDRA approach for modeling helicopter based on Lagrange dynamics

In order to accelerate the algorithm speed of dynamic model of helicopter, an IDRA approach for modeling helicopter was proposed and a dynamic model of six degrees of freedom (6 DOF) combining flying and landing was established in this paper. As the dynamic model is derived from the Lagrange equation of a non-conservative system, treating micro displacements and rotating angles of airframe in a simulation step as generalized coordinates, the relationship between energy dissipation, kinetic energy, potential energy and the generalized coordinates was analyzed. Finally, the reliability of this method and real-time of dynamic model were verified on the experimental platform of helicopter flight simulator, which could provide reliable theoretical foundation for solving the retardance of data transfer of helicopter simulator.

Robust Control of Bench-top Helicopter Using Quantitative Feedback Theory

A three degree of freedom (3-DOF) bench-top helicopter is a simplified aerial vehicle which is used to study the behaviors of the helicopter as well as testing multiple flight control approaches for their efficiency. Designing helicopter’s dynamic control is a challenging task due to the presence of high uncertainties and non-linear behavior. In this study, Quantitative Feedback Theory (QFT) is proposed to achieve robust control over the helicopter model. It utilizes frequency domain methodology which ensures plant’s stability by considering the feedback of the system and thus removing the effect of disturbances and reducing sensitivity of parameter’s variation. The proposed technique is tested against LQR-tuned PID controller to demonstrate its procedures as well as its performance. Simulation results obtained through MATLAB Simulink software shown us that QFT algorithm managed to reduce percentage of overshoot and settling time about 50% and 30% respectively over the classical PID controller. DOI: http://dx.doi.org/10.11591/telkomnika.v14i3.7899 Full Text: PDF

Eigenstructure Control: A Rotorcraft Handling Qualities Engineering Tool

This paper details a design methodology to derive flight control laws for a Bo105 helicopter model to meet ADS-33E-PRF handling qualities requirements. The feedback controller consists of angular rate sensors and flow angle rate estimates as feedback variables. The flow angle rate estimates are derived fromangular rate sensor signals using kinematic relationships. Longitudinal cyclic, lateral cyclic, and tail rotor are used as control variables. This core inner loop design using feedback signals derived only from inertial rate sensors meets the sensor redundancy (triplex) requirements for a digital fly-by-wire feedback system. Based on flightmechanics analysis, a lowcomplexity controller structure is postulated by selectively feeding back output signals to individual control channels. The primary objective of the postulated controller is to reduce the strong pitch to roll cross-coupling, inherent in the Bo105 model. However, instead of a loop at a time design procedure, typically adopted in classical control design, the design optimization is carried out by formulating an equivalent eigenstructure assignment problem that embeds the postulated controller. This approach results in a control methodology acting as an effective bridge between classical and multivariable design methods. Finally, using a recently developed tunable explicit model following problem formulation, a two-axis attitude command system is also designed. This command controller provides decoupled attitude command functions for pitch, and roll channels.

An improved nonlinear model for a helicopter and its self-repairing control with multiple faults via quantum information technique

In this paper, an improved nonlinear model for a 3-DOF helicopter and its self-repairing control scheme are investigated via quantum information technique. Firstly, adopting the mechanism analysis, a modified dynamic model is developed, in which the couplings among axes are considered. Such a modeling scheme is useful for applications when the accuracy of original model can not be satisfied. Then, a reconfigurable control scheme is designed for the twin rotor helicopter with multiple faults and parametric uncertainties, which combines active disturbance rejection control method with model reference adaptive control method. In addition, quantum information technique is used to increase the accuracy of self-repairing control of helicopter. Finally, simulation verification is presented in both aspects of modeling and control. The effectiveness and feasibility of the proposed scheme are verified by comparative simulations.

The Attitude Control Based on Active Disturbance Rejection Control for the Small-Scale Unmanned Helicopter

This paper presents a design of three channel controller based on active disturbance rejection control which has a fast response, high control precision, good robustness, strongly adaptability. This design approach does not need accurate mathematics model of the small unmanned helicopter. Input-output feedback linearization is intended primarily for the system output and system control input to establish a direct relation. The final aim is to develop a robust tracking control scheme which ensures that the outputs of closedloop system track the given expectations. There results of simulations show the satisfactory tracking performance and the great ability to suppress disturbances.

Voluntary Pilot Action Through Biodynamics for Helicopter Flight Dynamics Simulation

This work presents the integration of detailed models of a pilot controlling a helicopter along the heave axis through the collective control inceptor. The action on the control inceptor is produced through a biomechanical model of the pilot’s limbs, by commanding the activation of the related muscle bundles. Such activation, in turn, is determined by defining the muscle elongations required to move the control inceptor in order to obtain the control of the vehicle according to a high-level model of the voluntary action of the pilot acting as a regulator for the vehicle. The biomechanical model of the pilot’s limbs and the aeromechanical model of the helicopter are implemented in a general-purpose multibody simulation. The helicopter model, the biomechanical model of the pilot’s limbs, the cognitive model of the pilot, and their integration are discussed. The integrated model is applied to the simulation of simple, yet representative, mission task elements.

Engine-driven electrization of aircraft as a radio interference source

Field measurements of the quasi-static electrical fields emerging due to the in-flight electrization of low-speed low-altitude aircraft (helicopters) were performed for the first time. It was found that the electrization of helicopters with gas turbine power plants is of a engine-driven nature: the accumulation of static positive charge at the fuselage is induced by a unipolar negatively charged exhaust stream. A static positive fuselage potential that reaches +30 or even +35 kV for certain helicopter models was determined. If dielectric and composite materials are used in the construction of helicopters and specific parts of the aircraft are isolated electrically from the fuselage, differential electrization occurs. In view of the high absolute value of the fuselage potential, this electrization results in the generation of high-voltage discharges that serve as a source of intense radio interference within a frequency band of from several megahertz to several hundred megahertz.

An Affine Parameter Dependent Controller for an Autonomous Helicopter at Different Flight Conditions

In this paper we address the design of a controller that achieves stabilization and reference tracking at different flight conditions for an unmanned helicopter. The controller proposed is in the form of an H-infinity gain-scheduler, and is used for stabilization and reference tracking, for the 4 axis autopilot. (heave, pitch, roll and yaw control) A nonlinear helicopter model has been built, trimmed and linearized at different flight conditions. Based on the linearized models an approximate affine parameter dependent model has been constructed. Then, a linear parameter dependent controller is synthesized which stabilizes the affine parameter dependent helicopter model. By doing so, a single controller achieves stabilization and reference tracking of a family of linear models by scheduling the controller gains based on the online measurement of the scheduling parameter, which is the forward velocity. Moreover, the affine parameter dependent controller is fitted into the nonlinear helicopter model. It is seen that this single parameter dependent controller successfully stabilizes the nonlinear helicopter model at different flight conditions.

A New Turbo-shaft Engine Control Law during Variable Rotor Speed Transient Process

AbstractA closed-loop control law employing compressor guided vanes is firstly investigated to solve unacceptable fuel flow dynamic change in single fuel control for turbo-shaft engine here, especially for rotorcraft in variable rotor speed process. Based on an Augmented Linear Quadratic Regulator (ALQR) algorithm, a dual-input, single-output robust control scheme is proposed for a turbo-shaft engine, involving not only the closed loop adjustment of fuel flow but also that of compressor guided vanes. Furthermore, compared to single fuel control, some digital simulation cases using this new scheme about variable rotor speed have been implemented on the basis of an integrated system of helicopter and engine model. The results depict that the command tracking performance to the free turbine rotor speed can be asymptotically realized. Moreover, the fuel flow transient process has been significantly improved, and the fuel consumption has been dramatically cut down by more than 2% while keeping the helicopter level fight unchanged.

Co-Evolutionary Algorithm between Helicopter and Submarine

A co-evolutionary algorithm is proposed for the play between a submarine and a helicopter equipped with dipping sonar. First, the theoretical foundation of co-evolution is elaborated. The movement model of helicopter and submarine, the detection model of dipping sonar under certain ocean environment are established. After defining the strategies of helicopter and submarine and fitness evaluation methods, the process of co-evolutionary algorithm is described. The optimal strategy of helicopter after helicopter evolution, and the optimal strategies of both helicopter and submarine after co-evolution are given

Helicopter Control Energy Reduction Using Moving Horizontal Tail.

Helicopter moving horizontal tail (i.e., MHT) strategy is applied in order to save helicopter flight control system (i.e., FCS) energy. For this intention complex, physics-based, control-oriented nonlinear helicopter models are used. Equations of MHT are integrated into these models and they are together linearized around straight level flight condition. A specific variance constrained control strategy, namely, output variance constrained Control (i.e., OVC) is utilized for helicopter FCS. Control energy savings due to this MHT idea with respect to a conventional helicopter are calculated. Parameters of helicopter FCS and dimensions of MHT are simultaneously optimized using a stochastic optimization method, namely, simultaneous perturbation stochastic approximation (i.e., SPSA). In order to observe improvement in behaviors of classical controls closed loop analyses are done.

A211 Particle Swarm Optimizationを用いたヘリコプタモデルの機構パラメタ最適化(OS11 自律知能無人ビークルの運動と制御2)

A211 Particle Swarm Optimizationを用いたヘリコプタモデルの機構パラメタ最適化(OS11 自律知能無人ビークルの運動と制御2)

Chaotic Artificial Bee Colony Algorithm for System Identification of a Small-Scale Unmanned Helicopter

The purpose of this paper is devoted to developing a chaotic artificial bee colony algorithm (CABC) for the system identification of a small-scale unmanned helicopter state-space model in hover condition. In order to avoid the premature of traditional artificial bee colony algorithm (ABC), which is stuck in local optimum and can not reach the global optimum, a novel chaotic operator with the characteristics of ergodicity and irregularity was introduced to enhance its performance. With input-output data collected from actual flight experiments, the identification results showed the superiority of CABC over the ABC and the genetic algorithm (GA). Simulations are presented to demonstrate the effectiveness of our proposed algorithm and the accuracy of the identified helicopter model.

Control Design of Mixed Sensitivity Problem for Educational Model of Helicopter

The paper deals with the design of H-∞ robust controller, particularly with mixed sensitivity problem for elevation control. It briefly introduces basic mathematical background concerning robust control approach, which is then applied for typical example of MIMO system, that is a helicopter model. The obtained results are verified on real educational physical model CE 150 by Humusoft, ltd.

Decentralized output-feedback formation control of multiple 3-DOF laboratory helicopters

The decentralized formation control problem of multiple 3-degree of freedom laboratory helicopter models is studied on directed communication topologies in this paper. The laboratory helicopter models are subjected to non-linearity, under-actuated, and equipped only with angular position sensors. We present a decentralized formation controller which includes a non-linear uncertainty and disturbance estimation (UDE) term to compensate the model uncertainties and disturbances in each helicopter and from its neighborhood. The UDE consists of a second-order auxiliary system and a discontinuous term, neither the measurement of angular velocity nor its asymptotic estimation is required. Convergence of the formation tracking error is analyzed using invariance-like theorems. It is also proved that the UDE term will converge to the actual uncertainties and disturbances. Simulation results show that, on a one-way communication topology which only contains one spanning tree, a group of four helicopters reaches the desired formation shape while tracking a given reference trajectory using proposed method.