A new hybrid control methodology for a morphing aircraft wing-tip actuation mechanism

2019 ◽  
Vol 123 (1269) ◽  
pp. 1757-1787
Author(s):  
M. J. Tchatchueng Kammegne ◽  
R. M. Botez

ABSTRACTThe focus of this paper is on the modelling of miniature electromechanical actuators used in a morphing wing application, on the development of a control concept for these actuators, and on the experimental validation of the designed control system integrated in the morphing wing-tip model for a real aircraft. The assembled actuator includes as its main component a brushless direct current motor coupled to a trapezoidal screw by using a gearing system. A Linear Variable Differential Transformer (LVDT) is attached on each actuator giving back the actuator position in millimetres for the control system, while an encoder placed inside the motor provides the position of the motor shaft. Two actuation lines, each with two actuators, are integrated inside the wing model to change its shape. For the experimental model, a full-scaled portion of an aircraft wing tip is used with the chord length of 1.5 meters and equipped on the upper surface with a flexible skin made of composite fibre materials. A controllable voltage provided by a power amplifier is used to drive the actuator system. In this way, three control loops are designed and implemented, one to control the torque and the other two to control the position in a parallel architecture. The parallel position control loops use feedback signals from different sources. For the first position control loop, the feedback signal is provided by the integrated encoder, while for the second one, the feedback signal comes from the LVDT. For the experimental model, the parameters for the torque control, but also for the position control-based encoder signal, are implemented in the power amplifier energising the electrical motor. On the other hand, a National Instruments real-time system is used to implement and test the position control-based LVDT signal. The experimental validation of the developed control system is realised in two independent steps: bench testing with no airflow and wind-tunnel testing. The pressure data provided by a number of Kulite sensors equipping the flexible skin upper surface and the infrared thermography camera visualisations are used to estimate the laminar-to-turbulent transition point position.

Actuators ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 19 ◽  
Author(s):  
Bao Tri Diep ◽  
Ngoc Diep Nguyen ◽  
Thanh T. Tran ◽  
Quoc Hung Nguyen

This research focuses on the development of a new 3-DOF (Degree of Freedom) force feedback system featuring a spherical arm mechanism and three magnetorheological (MR) brakes, namely two rotary MR brakes and one linear MR brake. The first rotary MR brake is integrated in the waist joint to reflect the horizontal tangent force, the other rotary MR brake is integrated in the shoulder joint to reflect the elevation tangent force, while the linear MR brake is integrated in the sliding joint of the arm to reflect the radial force (approach force). The proposed configuration can reflect a desired force to the operator at the end-effectors of the arm independently in 3 DOFs by controlling the current applied to the coils of the MR brakes. After the introduction, the configuration of the proposed force feedback system is presented. Afterward, the design and conducted simulation of the MR brakes for the systems are provided. The prototype of the force feedback system, which was manufactured for the experiment, is then presented as well as some of the obtained experimental results. Finally, the proposed control system is presented and its implementation to provide a desired feedback force to the operator is provided.


1962 ◽  
Vol 84 (1) ◽  
pp. 54-60 ◽  
Author(s):  
J. C. Nicklas ◽  
H. C. Vivian

A gyro-free nonlinear attitude control system for a spacecraft is analyzed. On-off jet actuators are used. Hysteresis and a dead zone are intentionally put into the system. Under certain conditions the feedback signal in the control system is proportional to an angular velocity increment of the system. This is called the derived-rate increment feedback signal. The analysis for a single axis of the attitude control system is given in two parts. One part is concerned with the performance of the system in a limit cycle. The other part discusses the convergence to a limit cycle after a disturbance has occurred. Experimental results verify the results of the analysis. Typical results show the performance of the system during convergence to and operation in a limit cycle. Although the technique is described for use in an attitude control system, it can be successfully employed in other applications.


2014 ◽  
Vol 599-601 ◽  
pp. 1128-1134
Author(s):  
Xiang Hui Zhang ◽  
Zhan Wen Sun ◽  
Jin Zhao ◽  
Hua Dong Yu

To achieve the control of movement speed stability and location accuracy of two-dimensional motion platform, considered the movement characteristics of sliding table drive motor, a motion control method based on servo motor encoder feedback signal is proposed in this paper. By using real-time emulation platform of XPC target and related peripheral circuit, completed the construction of the motion control system. By analyzing the experimental data, proved the two-dimensional motion platform control system based on xPC target operation stable, meet the position control accuracy, motion response rapidly, and easy to adjust the control parameters requirements, and own high engineering practical value.


Author(s):  
Debargha Chakraborty ◽  
Binanda Kishore Mondal ◽  
Souvik Chatterjee ◽  
Sudipta Ghosh

1995 ◽  
Vol 31 (8) ◽  
pp. 301-309 ◽  
Author(s):  
Govert D. Geldof

In integrated water management, the issues are often complex by nature, they are capable of subjective interpretation, are difficult to express in standards and exhibit many uncertainties. For such issues, an equilibrium approach is not appropriate. A non-equilibrium approach has to be applied. This implies that the processes to which the integrated issue pertains, are regarded as “alive”’. Instead of applying a control system as the model for tackling the issue, a network is used as the model. In this network, several “agents”’ are involved in the modification, revision and rearrangement of structures. It is therefore an on-going renewal process (perpetual novelty). In the planning process for the development of a groundwater policy for the municipality of Amsterdam, a non-equilibrium approach was adopted. In order to do justice to the integrated character of groundwater management, an approach was taken, containing the following features: (1) working from global to detailed, (2) taking account of the history of the system, (3) giving attention to communication, (4) building flexibility into the establishing of standards, and (5) combining reason and emotions. A middle course was sought, between static, rigid but reliable on the one hand; dynamic, flexible but vague on the other hand.


Author(s):  
Qixin Zhu ◽  
Lei Xiong ◽  
Hongli Liu ◽  
Yonghong Zhu ◽  
Guoping Zhang

Background: The conventional method using one-degree-of-freedom (1DOF) controller for Permanent Magnet Synchronous Motor (PMSM) servo system has the trade-off problem between the dynamic performance and the robustness. Methods: In this paper, by using H∞ control theory, a novel robust two-degree-of-freedom (2DOF) controller has been proposed to improve the position control performance of PMSM servo system. Using robust control theory and 2DOF control theory, a H∞ robust position controller has been designed and discussed in detail. Results: The trade-off problem between the dynamic performance and robustness which exists in one-degree-of-freedom (1DOF) control can be dealt with by the application of 2DOF control theory. Then, through H∞ control theory, the design of robust position controller can be translated to H∞ robust standard design problem. Moreover, the control system with robust controller has been proved to be stable. Conclusion: Further simulation results demonstrate that compared with the conventional PID control, the designed control system has better robustness and attenuation to the disturbance of load impact.


Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 747
Author(s):  
Mai The Vu ◽  
Tat-Hien Le ◽  
Ha Le Nhu Ngoc Thanh ◽  
Tuan-Tu Huynh ◽  
Mien Van ◽  
...  

Underwater vehicles (UVs) are subjected to various environmental disturbances due to ocean currents, propulsion systems, and un-modeled disturbances. In practice, it is very challenging to design a control system to maintain UVs stayed at the desired static position permanently under these conditions. Therefore, in this study, a nonlinear dynamics and robust positioning control of the over-actuated autonomous underwater vehicle (AUV) under the effects of ocean current and model uncertainties are presented. First, a motion equation of the over-actuated AUV under the effects of ocean current disturbances is established, and a trajectory generation of the over-actuated AUV heading angle is constructed based on the line of sight (LOS) algorithm. Second, a dynamic positioning (DP) control system based on motion control and an allocation control is proposed. For this, motion control of the over-actuated AUV based on the dynamic sliding mode control (DSMC) theory is adopted to improve the system robustness under the effects of the ocean current and model uncertainties. In addition, the stability of the system is proved based on Lyapunov criteria. Then, using the generalized forces generated from the motion control module, two different methods for optimal allocation control module: the least square (LS) method and quadratic programming (QP) method are developed to distribute a proper thrust to each thruster of the over-actuated AUV. Simulation studies are conducted to examine the effectiveness and robustness of the proposed DP controller. The results show that the proposed DP controller using the QP algorithm provides higher stability with smaller steady-state error and stronger robustness.


IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 21965-21985
Author(s):  
Felipe Donoso ◽  
Roberto Cardenas ◽  
Mauricio Espinoza ◽  
Jon Clare ◽  
Andres Mora ◽  
...  

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