Active Load-Sensitive Electro-Hydrostatic Actuator for More Electric Aircraft

In the flight control system, using an electro-hydrostatic actuator (EHA) instead of the currently used relatively mature electro-hydraulic valve-controlled actuator, there are three prevailing concerns, namely heating, size, and stiffness. This paper proposes a novel principle EHA, called active load-sensitive EHA (ALS-EHA), which can actively realize the adaptive adjustment of pump displacement with load pressure. Its principle analysis and mathematical modeling based on the direct load-sensitive EHA (DLS-EHA) configuration is done to obtain the relationship between motor current and hydraulic reduction ratio. Then, its stiffness characteristics are analyzed, especially the influence of hydraulic reduction ratio on impedance at low frequencies combined with investigating the power matching of ALS-EHA. A comparative experiment between the developed ALS-EHA and the EHA with fixed pump displacement and variable motor speed (EHA-FPVM) was carried out. The results reveal that the proposed ALS-EHA can reduce the motor heating and its displacement tracking error is smaller near zero speed owing to its higher impedance from the lower hydraulic reduction ratio under heavy load conditions.

Download Full-text

Integral Command Filtered Backstepping Control of a Flexible UAV

MATEC Web of Conferences ◽

10.1051/matecconf/201816005005 ◽

2018 ◽

Vol 160 ◽

pp. 05005

Author(s):

Ding Han ◽

Lin Yan ◽

Guozheng Yan ◽

Xiaoliang Wang ◽

Dengping Duan

Keyword(s):

Control Systems ◽

Flight Control ◽

Research Effort ◽

Tracking Error ◽

Rate Of Change ◽

Body Motion ◽

Nonlinear Controller ◽

Integral Action ◽

Tracking Ability ◽

Backstepping Controller

Airships, as the significant UAV, have a need for greater autonomy in their new missions. Therefore, airship flight control systems require precise dynamic modeling, taking into account the effect of flexibility and the interaction with aerodynamic forces. This research effort develops an efficient modeling of the autonomous flexible airship. The formalisation used is based on the Lagrange method. The resulting model includes the rigid body motion, the elastic deformation, and the coupling between them. Based on the precise flexible dynamic model, a novel backstepping nonlinear controller with integral action is proposed for motion control systems. The resulting feedback controller is able to adapt to actuator performance limitations, such as limitations in magnitude and rate of change of rudder, than conventional backstepping controller without integral action. With the deformation considered, the presented controller could resist the flexible uncertainty effect, and the system’s trajectory tracking ability is significantly improved. The approach guarantees exponential stability of a compensated tracking error in the sense of Lyapunov.

Download Full-text

The Design and Evaluation of Complex Systems: Application to a Man-Machine Interface for Aerial Navigation

Proceedings of the Human Factors Society Annual Meeting ◽

10.1177/107118137902300119 ◽

1979 ◽

Vol 23 (1) ◽

pp. 75-79 ◽

Cited By ~ 1

Author(s):

Dennis B. Beringer

Keyword(s):

Flight Control ◽

Tracking Error ◽

Data Entry ◽

Digital Data ◽

Training Time ◽

Subsequent Performance ◽

Navigation Data ◽

Wide Range ◽

Dynamic Map ◽

Aerial Navigation

Systematic and economic design and evaluation strategies were applied to a computer-generated 4-D aerial navigation system. During the evaluation each of 24 experienced instrument pilots received training in a PLATO-based digital flight simulator using either a keyboard entry/static map, keyboard entry/dynamic map, or touch entry/dynamic map system. Tasks performed during the execution of an area navigation course included continuous flight control, navigation data updating, digital data entry, and amended course plotting. Digital data entry training time was comparable for all three systems but the touch-map proved superior for the plotting tasks, greatly reducing training and task execution times while virtually eliminating errors. Subsequent performance evaluation showed that the touch-map reduced flight path tracking error, increased processing rates on a digit-cancelling secondary task, and increased the accuracy of manual plotting operations. It was concluded that a touch entry system could significantly reduce cockpit workload across a wide range of operational environments.

Download Full-text

Research on Power Matching and Energy Optimal Control of Active Load-Sensitive Electro-Hydrostatic Actuator

IEEE Access ◽

10.1109/access.2020.3011629 ◽

2021 ◽

pp. 1-1

Author(s):

Ligang Huang ◽

Tian Yu ◽

Zongxia Jiao ◽

Yanpeng Li

Keyword(s):

Optimal Control ◽

Power Matching ◽

Active Load

Download Full-text

Four-Rotor Autonomous Vehicle

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.505-506.286 ◽

2014 ◽

Vol 505-506 ◽

pp. 286-291

Author(s):

Shu Yun Wu ◽

Xu Hao Lv

Keyword(s):

Flight Control ◽

Autonomous Vehicle ◽

Computer Control ◽

Control Unit ◽

Micro Air Vehicles ◽

Motor Speed ◽

Single Chip ◽

Flight Mode ◽

Reliable Performance ◽

Control Flight

Four rotary-wing micro air vehicles use four motors as the power unit, by adjusting the motor speed control flight of underactuated systems [. In order to achieve four-rotor autonomous vehicle autonomous flight control, preliminary design of flight control system, and use F5F100LEA single-chip as computer control unit, Proposed the flight system hardware design. Vehicle has the advantages of light weight, small size, low power consumption. After several laboratory tests, the design and reliable performance, to meet the aircraft take off, hover, landing flight mode control requirements.

Download Full-text

Strictly-lower-convex-function-constructing disturbance observer based adaptive back stepping control for hypersonic flight vehicles

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1177/0954410017715279 ◽

2017 ◽

Vol 232 (13) ◽

pp. 2552-2564

Author(s):

Jingxing Zuo ◽

Yunjie Wu ◽

Lianghua Sun

Keyword(s):

Convex Function ◽

Flight Control ◽

Disturbance Observer ◽

Sliding Mode ◽

Tracking Error ◽

Small Region ◽

Control Laws ◽

Hypersonic Flight ◽

Flight Vehicles ◽

Adaptive Laws

This study concerns with the attitude and velocity tracking control problem for the longitudinal model of hypersonic flight vehicles, which is nonlinear in aerodynamics with model uncertainties and external disturbances. By employing back stepping sliding mode method and the strictly-lower-convex-function-constructing nonlinear disturbance observer (SNDOB), a novel composite controller is proposed to guarantee the system tracking error to converge to a small region containing the origin. Besides, several proper adaptive laws are also introduced to make the controller avoid of the differential explosion problem and be chatter-free. Compared with other robust flight control approaches, key novelties of the developed method are that one new SNDOB is proposed and drawn into the virtual control laws at each step to compensate the disturbances and that adaptive laws are utilized to simplify the tedious and complicated differential operations. Finally, it is demonstrated by the simulation results that the new method exhibits not only an excellent robustness but also a better disturbance rejection performance than the convention approach.

Download Full-text

Hybrid Electroactive Wings Morphing for Aeronautic Applications

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.198.200 ◽

2013 ◽

Vol 198 ◽

pp. 200-205 ◽

Cited By ~ 8

Author(s):

Maxime Chinaud ◽

Johannes Scheller ◽

Jean François Rouchon ◽

Eric Duhayon ◽

Marianna Braza

Keyword(s):

Flight Control ◽

Research Program ◽

High Frequency ◽

Coupling Effect ◽

Large Displacements ◽

Wind Tunnel Experiments ◽

Low Frequencies ◽

Electroactive Materials ◽

Morphing Wings ◽

Cooling Mechanism

As part of the RTRA funded EMMAV (Electroactive Morphing for Micro-Airvehicles) research program electroactive materials were studied as well as their applications as actuators for morphing wings. The aim of this research program is to study both the actuation with large displacements at low frequencies as well as low displacement, high frequency actuation. The large displacement actuation, which targets primarily the flight control, is achievable using Shape Memory Alloys (SMA) while high frequency; low displacement actuation can be achieved using piezoelectric actuators [. This high frequency actuation is especially interesting for improving the aeroelastic coupling effect inducing both noise and drag. This paper describes the construction of a prototype incorporating piezoelectric and SMA based actuation mechanisms. Furthermore, a cooling mechanism for SMAs is described aiming at improving the cycle time of the actuator. The developed prototype is to be evaluated during wind-tunnel experiments showing the influence of the actuation on the fluid.

Download Full-text

High-frequency robust position control of a nonlinear piezoelectric bending actuator

Journal of Vibration and Control ◽

10.1177/1077546319900851 ◽

2020 ◽

Vol 26 (17-18) ◽

pp. 1560-1573 ◽

Cited By ~ 2

Author(s):

Pouyan Shahabi ◽

Hamed Ghafarirad ◽

Afshin Taghvaeipour

Keyword(s):

High Frequency ◽

Position Control ◽

Tracking Error ◽

Beam Theory ◽

Cell Manipulation ◽

Average Error ◽

Position Tracking ◽

Nonlinear Dynamic Model ◽

Low Frequencies ◽

Bending Actuator

Piezoelectric bending actuators have been widely used in a variety of micro- and nano-applications, including atomic force microscopy, micro assembly, cell manipulation, and in general, micro electromechanical systems. However, their control algorithms at low frequencies suffer from nonlinearities such as hysteresis in high voltages and creep in long-time static applications. Also, in high-frequency applications, especially near the actuator natural frequencies, the actuator dynamic is greatly affected by the material nonlinearity. Therefore, the control approaches based on the linear dynamic modeling cannot be effective at high frequencies. Thus, the position control of the foregoing actuators become challenging, and it has been of researchers’ interests in the last decade. In this article, the robust position control of a bimorph piezoelectric bending actuators is investigated. In this regard, based on the nonlinear constitutive equations and the Euler–Bernoulli beam theory, a nonlinear dynamic model is presented. Then, to track a desired motion trajectory, an observer-based robust position control algorithm is proposed. The proposed control methodology is able to accommodate parametric uncertainties and other un-modeled dynamics. Also, it ensures the elimination of the position tracking error in the presence of the estimated states. Finally, the tracking ability of the controller is demonstrated in an experimental study. The experimental results show that the identification of the system is properly conducted with the average error of 5.5%. Also, the efficiency of the robust controller is proved with the error of 3.7% and 4.9% in the position tracking of the actuator inside and outside of the identified region, respectively.

Download Full-text

Disturbance observer based dynamic surface flight control for an uncertain aircraft

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1177/0954410017691793 ◽

2017 ◽

Vol 232 (4) ◽

pp. 729-744 ◽

Cited By ~ 3

Author(s):

Jianjun Ma ◽

Peng Li ◽

Zhiqiang Zheng

Keyword(s):

Flight Control ◽

Disturbance Observer ◽

Sliding Mode ◽

Tracking Error ◽

Small Neighborhood ◽

Dynamic Surface ◽

Nonlinear Disturbance Observer ◽

Actuator Dynamics ◽

Highly Nonlinear ◽

Nonlinear Disturbance

To handle the flight control problem of an uncertain aircraft with highly nonlinear characteristics, internal uncertainties and external disturbances, an adaptive dynamic surface controller based on nonlinear disturbance observer is designed in this paper. A novel nonhomogeneous nonlinear disturbance observer is designed to approximate the uncertainties and disturbances, which can exactly estimate the disturbances in finite time. Dynamic surface control is utilized to avoid the explosion of complexity in traditional backstepping design. Through Lyapunov synthesis, the closed-loop control system is demonstrated to be semi-globally uniformly ultimately bounded and the tracking error converges to a small neighborhood of origin. Besides, actuator dynamics are taken into account, and the controller for actuator dynamics with consideration of limitation is developed based on sliding-mode control theory. The effectiveness of the proposed control is shown by simulation experiments.

Download Full-text

Sliding Mode Control for NSVs with Input Constraint Using Neural Network and Disturbance Observer

Mathematical Problems in Engineering ◽

10.1155/2013/904830 ◽

2013 ◽

Vol 2013 ◽

pp. 1-12 ◽

Cited By ~ 11

Author(s):

Yan-long Zhou ◽

Mou Chen

Keyword(s):

Sliding Mode Control ◽

Flight Control ◽

Disturbance Observer ◽

Sliding Mode ◽

Coupling Parameter ◽

Tracking Error ◽

Space Vehicles ◽

Strong Nonlinearity ◽

Observer Error ◽

Mode Control

The sliding mode control (SMC) scheme is proposed for near space vehicles (NSVs) with strong nonlinearity, high coupling, parameter uncertainty, and unknown time-varying disturbance based on radial basis function neural networks (RBFNNs) and the nonlinear disturbance observer (NDO). Considering saturation characteristic of rudders, RBFNNs are constructed as a compensator to overcome the saturation nonlinearity. The stability of the closed-loop system is proved, and the tracking error as well as the disturbance observer error can converge to the origin through the Lyapunov analysis. Simulation results are presented to demonstrate the effectiveness of the proposed flight control scheme.

Download Full-text