Science and Technology on Rotorcraft Aeromechanics Laboratory

Jingdezhen, China

Science and Technology on Rotorcraft Aeromechanics Laboratory

Jingdezhen, China
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Pan Z.,Beihang University | Wang W.,Beihang University | Song S.,Beihang University | Lu K.,Science and Technology on Rotorcraft Aeromechanics Laboratory
CGNCC 2016 - 2016 IEEE Chinese Guidance, Navigation and Control Conference | Year: 2016

Tiltrotor aircraft is a kind of aircraft which can fly as a fixed wing aircraft or a helicopter by tilting its two rotors' mast angle, which means it has both the advantages of helicopter and fixed wing aircraft. To control it well, a nonlinear mathematical model based on Pitt-Peters dynamic inflow theory is established. Since traditional control method based on linearized model needs extensive gain scheduling with the mast angle and flight state, a novel control method named active disturbance rejection sliding mode controller (ADRSMC) based on active disturbance rejection controller (ADRC) and sliding mode controller (SMC) is designed. First of all, a tracking differentiator (TD) is utilized to get the command of attitude and angular rate. Because the disturbance of the novel model includes the model error and coupling between different channels, a novel sliding mode extended state observer (SMESO) base on sliding mode theory is developed to estimate the disturbance of model. After that, a novel control law based on dynamic surface control theory is developed. And the stability of ADRSMC is proved. The parameters of ADRSMC are not changed during the whole process of simulation. Simulation results in various flight conditions show that ADRSMC is feasible and parameters are available in a wide range. © 2016 IEEE.


Yan S.,Beihang University | Wang W.,Beihang University | Wu S.,Beihang University | Lu K.,Science and Technology on Rotorcraft Aeromechanics Laboratory
Proceedings of the 29th Chinese Control and Decision Conference, CCDC 2017 | Year: 2017

In this paper, by studying the foraging behavior of ducks, a new bionic clustering intelligent algorithm - duck pack algorithm (DPA) is proposed and applied to route planning. The foraging behavior of the duck pack is dependent on imprinting behavior and food orientation, and this is why the ducks are different from other kinds of packs. To obtain the duck pack algorithm, the imprinting behavior and food orientation are abstracted into two operators and then the two operators are merged into an iterative process. Then the DPA is applied to route planning, and it can be found that DPA converges more quickly and the path generated by the DPA algorithm is smoother than that generated by the standard DE. This shows the reasonableness of the algorithm, and proves that the DPA algorithm is superior to the standard DE algorithm in stability and superiority. © 2017 IEEE.


Wang G.,Northwestern Polytechnical University | Zeng Z.,Northwestern Polytechnical University | Suo Q.,Science and Technology on Rotorcraft Aeromechanics Laboratory
AIAA Atmospheric Flight Mechanics Conference, 2015 | Year: 2015

The unsteady Navier-Stokes equation and rigid body equations of 6-DOF motion are solved using variable-step coupling computation method to simulate and analyze the flight trajectory of U.S. Army Research Laboratory spinning projectile test model. At the initial state, the spinning projectile has a high revolving speed. During the free-flight process, the revolving speed will gradually decrease, due to the effect of aerodynamic resistance. Accordingly, the unsteady aerodynamic effect caused by spinning will gradually diminish. Based on the above characteristics, at the starting stage of the simulation, a smaller time step-size will be chosen for describing the intense unsteady aerodynamic effect. Then the time step-size will gradually increase with the declining revolving speed to save the computing time. The unsteady aerodynamic computations uses an in-house hybrid unstructured Navier-Stokes flow solver (HUNS3D). Time marching technique uses a non-uniform step-size dual time-stepping method. The rigid body equations are solved using Variable-step-size Adams prediction-correction method. Both variable-step-size and fixed-step-size methods are applied to solve the CFD/RBD coupling system and predict the trajectory of the test model. Computed results are found to be generally in good agreement with experiment data and numerical results extracted from reference. For the same initial step-size, the computational time for the variable-step-size method is reduced nearly by half of that of the fixed-step-size method. © 2015 by the American Institute of Aeronautics and Astronautics, Inc.


Zhu Y.,Science and Technology on Rotorcraft Aeromechanics Laboratory | Lu Y.-H.,Science and Technology on Rotorcraft Aeromechanics Laboratory | Ling A.-M.,Science and Technology on Rotorcraft Aeromechanics Laboratory
IOP Conference Series: Materials Science and Engineering | Year: 2017

In order to accurately predict the dynamic instability of helicopter ground resonance, a modeling and simulation method of helicopter ground resonance considering nonlinear dynamic characteristics of components (rotor lead-lag damper, landing gear wheel and absorber) is presented. The numerical integral method is used to calculate the transient responses of the body and rotor, simulating some disturbance. To obtain quantitative instabilities, Fast Fourier Transform (FFT) is conducted to estimate the modal frequencies, and the mobile rectangular window method is employed in the predictions of the modal damping in terms of the response time history. Simulation results show that ground resonance simulation test can exactly lead up the blade lead-lag regressing mode frequency, and the modal damping obtained according to attenuation curves are close to the test results. The simulation test results are in accordance with the actual accident situation, and prove the correctness of the simulation method. This analysis method used for ground resonance simulation test can give out the results according with real helicopter engineering tests. © Published under licence by IOP Publishing Ltd.


Song S.,Beihang University | Wang W.,Beihang University | Lu K.,Science and Technology on Rotorcraft Aeromechanics Laboratory | Sun L.,Beihang University
Proceedings of the 2015 27th Chinese Control and Decision Conference, CCDC 2015 | Year: 2015

A tilt-rotor has a rotor on each side of its airframe and each rotor can be tilted to provide lift or thrust. With the tilt on rotors, the model of tilt-rotor has a significant change. Conventional control methods based on linearized model need extensive gain scheduling with the nacelle angle and flight condition. In order to alleviate this requirement, a design of attitude control based on ESO(Extended State Observer) is developed. The kernel of this method is the estimation and compensation of the disturbance on model. The disturbance includes the model error and coupling between different channels. By the compensation of the disturbance, the controller achieves the decoupling of the system and the compensation of model error and other disturbance at the same time. This control architecture is based on the nonlinear model of the aircraft and the parameters of the controller are available in wide ranges. Nonlinear feedback law is designed for outer loop controller to guarantee the dynamic performances. Simulation results in different flight conditions show that the design of attitude control is feasible. © 2015 IEEE.


Pan Z.,Beihang University | Wang W.,Beihang University | Xiong S.,Beihang University | Lu K.,Science and Technology on Rotorcraft Aeromechanics Laboratory
Proceedings of the 28th Chinese Control and Decision Conference, CCDC 2016 | Year: 2016

To control a slide to turn (STT) missile which attacks a ground moving target in the presence of input saturation, a three dimensional (3D) integrated guidance and control (IGC) law based on dynamic surface control and linear extended state observer (LESO) techniques is developed. Firstly, a novel 3D IGC model is built without assuming that the angle between line of sight (LOS) and missile velocity is small or almost constant. Then, to analyze the effect of input saturation, a Nussbaum function, a smooth tangent function, and an auxiliary system are introduced. The modeling error, acceleration of target and aerodynamic parameters perturbation are viewed as the overall system uncertainty which three linear extended state observers are designed to estimate. With the signal generated by the auxiliary system and uncertainty estimated from LESO, a robust controller utilizing dynamic surface control technique is designed to track the target. Besides, the stability of system is proved. Simulation results demonstrate the effectiveness of the law. © 2016 IEEE.


Lu K.,Science and Technology on Rotorcraft Aeromechanics Laboratory | Lu K.,Nanjing University of Aeronautics and Astronautics | Liu C.,Nanjing University of Aeronautics and Astronautics | Wang Z.,Science and Technology on Rotorcraft Aeromechanics Laboratory | Wang W.,Beihang University
Proceedings of the 28th Chinese Control and Decision Conference, CCDC 2016 | Year: 2016

In this paper, a flight dynamics model of a tiltrotor aircraft is developed used basic equations of motion. This model focuses on control aspect of tiltrotor and is able to show inherent tiltrotor characteristics; then a flight control system is designed used novel L1 adaptive control theory. The XV-15 tilt rotor aircraft is taken as an example to verify this modeling method and flight control system; finally, numerical simulations are presented to show the performance and robustness of the proposed controller. © 2016 IEEE.


Ke L.,Science and Technology on Rotorcraft Aeromechanics Laboratory | Wang Z.,Science and Technology on Rotorcraft Aeromechanics Laboratory | Yuan S.,Nanjing University of Aeronautics and Astronautics
2014 IEEE Chinese Guidance, Navigation and Control Conference, CGNCC 2014 | Year: 2015

Automated carrier landing of an Unmanned Air Vehicle is a complex process. To successfully complete the task of landing on carrier, firstly the guidance system should give UAV flight control system a proper landing trajectory, then the flight control system according to the instructions given by the guidance system of UAV make the UAV fly on the right track, finally realizing automatic landing on carrier. In this process the guidance system providing correct guidance signal is a key factor in the success of landing on carrier. Now most aircraft carriers have angled deck, so there are great differences to ground-based landing. In view of this situation, a guidance law is designed for UAV landing on carrier, and the simulation of guidance law is carried out. Because of the air flow disturbance behind of the carrier, the requirement of flight control system is robust, so, this paper introduces quantitative feedback robust control design method to design the flight controller, in order to guarantee the robustness of control system. The results show that the guidance law and flight control system designed in this paper could realize the UAV autonomous landing. © 2014 IEEE.


Wu H.-D.,Science and Technology on Rotorcraft Aeromechanics Laboratory | Tang Z.-F.,Science and Technology on Rotorcraft Aeromechanics Laboratory | Tang M.,Science and Technology on Rotorcraft Aeromechanics Laboratory
American Helicopter Society International - 2nd Asian/Australian Rotorcraft Forum, ARF 2013 and the 4th International Basic Research Conference on Rotorcraft Technology 2013, IBRCRT 2013 | Year: 2013

In this article, a numerical simulation method for the unsteady fanwing flowfield has been established by solving the N-S equations, based on the eccentric vortex exist inside fanwing. The aerodynamic characteristics of funwing under different state have been numerical simulation by using this method. The eccentric vortex inside fanwing have been discussed through the calculation results.


Huang S.,Science and Technology on Rotorcraft Aeromechanics Laboratory | Lin Y.,Science and Technology on Rotorcraft Aeromechanics Laboratory | Fan F.,Science and Technology on Rotorcraft Aeromechanics Laboratory | Liu Z.,Science and Technology on Rotorcraft Aeromechanics Laboratory
Transactions of Nanjing University of Aeronautics and Astronautics | Year: 2015

An iterative free-wake computational method is developed for the prediction of aerodynamic interaction characteristics between the twin rotors of a tandem helicopter. Here the mutual interaction effects between twin rotors are included, as well as those between the rotor and wake. A rotor wake model, blade aerodynamic model and rotor trim model are coupled during the process of solution. A new dual-rotor trim approach is presented to fit for the aerodynamic interaction calculations between tandem twin rotors. By the present method, the blade aerodynamic loads and rotor performance for the twin rotors under the interactional condition are calculated, and the comparisons with available experimental data are also made to indicate the capability of the proposed method. Then, the effects of such parameters as the longitudinal separation and axial separation between twin rotors on the aerodynamic interaction characteristics are analyzed. Based on the investigation, the conclusions are obtained to be of benefit to the configuration design of tandem rotors. Furthermore, the performance comparison between the tandem rotors and a single rotor is conducted. It is shown that the strongest interaction does not appear in a hover state, but in a low-speed forward flight state. ©, 2015, Nanjing University of Aeronautics an Astronautics. All right reserved.

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