Acceleration/Drift Feedback Control of MRD Connected Buildings

Author(s):  
Naresh K. Chandiramani ◽  
Gokarna B. Motra

Seismic response control of buildings connected by a magnetorheological damper (MRD) is studied. The desired control force is obtained using Linear Quadratic Gaussian (LQG) control with feedback of estimated states, or Optimal Static Output Feedback (OSOF) control using direct feedback of outputs. The damper input voltage is predicted using a Recurrent Neural Network (RNN). Various sensor configurations and state weightings are considered to obtain effective control. Effective control is possible using few sensors (eg. a single accelerometer with LQG-RNN).

2003 ◽  
Vol 22 (2) ◽  
pp. 97-108 ◽  
Author(s):  
Yan Sheng ◽  
Chao Wang ◽  
Ying Pan ◽  
Xinhua Zhang

This paper presents a new active structural control design methodology comparing the conventional linear-quadratic-Gaussian synthesis with a loop-transfer-recovery (LQG/LTR) control approach for structures subjected to ground excitations. It results in an open-loop stable controller. Also the closed-loop stability can be guaranteed. More importantly, the value of the controller's gain required for a given degree of LTR is orders of magnitude less than what is required in the conventional LQG/LTR approach. Additionally, for the same value of gain, the proposed controller achieves a much better degree of recovery than the LQG/LTR-based controller. Once this controller is obtained, the problems of control force saturation are either eliminated or at least dampened, and the controller band-width is reduced and consequently the control signal to noise ratio at the input point of the dynamic system is increased. Finally, numerical examples illustrate the above advantages.


Author(s):  
Ipar Ferhat ◽  
Cornel Sultan

Linear Quadratic Gaussian (LQG) control is developed for a prestressed square membrane with bimorph actuators attached to it. The membrane is modeled using the finite element method and the membrane is assumed to be clamped on all edges. After obtaining the mass, damping, stiffness and input matrices in second order form using the weak form Finite Element Method (FEM), the problem is represented in first order form to develop the LQG controller. To study the robustness of the system, the control and observer gain matrices developed for the nominal system are applied to systems obtained from the nominal system by modifying material properties and prestress.


2020 ◽  
Vol 51 (7-9) ◽  
pp. 119-126
Author(s):  
Shujing Sha ◽  
Zhongnan Wang ◽  
Haiping Du

With the development of automobile technology, the traditional passive suspension cannot meet people’s requirements for vehicle comfort and safety. For this reason, a variable damping semi-active suspension applied magnetorheological damper is proposed. By collecting various performance parameters of the front suspension, the optimal feedback control matrix is obtained by applying linear quadratic Gaussian control strategy, and the optimal damping force output is also obtained to improve comfort and vehicle safety by reducing vibration. The semi-active suspension model of a quarter vehicles was established by MATLAB/Simulink, and the simulation experiment was carried out. The results show that the semi-active suspension system with magnetorheological damper is superior to the traditional passive suspension in terms of vibration absorption; meanwhile, the root mean square values of vehicle acceleration, suspension dynamic deflection, tire dynamic travel, and tire dynamic load are reduced, which effectively improve the vehicle ride stability.


2007 ◽  
Vol 53 (2) ◽  
pp. 133-141 ◽  
Author(s):  
G. Roux ◽  
B. Dahhou ◽  
K. Najim ◽  
I. Queinnec

Author(s):  
J-H Kim ◽  
Y-H Kim

The present study considers the motion control of a cruise ship by using active stabilizing fins. One or two pairs of stabilizing fins are equipped to reduce the roll and/or pitch motions of the cruise ship. Each fin is controlled by algorithms based on proportional–integral–derivative (PID) and linear quadratic Gaussian (LQG) control. Numerical analysis of the wave-induced motion of a cruise ship with stabilizing fins is carried out by using the time-domain ship motion program which has been developed through this study. The resultant motion response as the performance of each controller is compared between different control algorithms. Based on the present simulation results, the stabilizing fin can be considered a good instrument to reduce pitch motion as well as roll motion of the present cruise ship model. The present results show that the PID control algorithm, a simple but practical algorithm, can be an appropriate method to reduce the roll motion in a moderate sea state, while the LQG control algorithm shows good performance in reducing not only the roll motion but also the coupled roll and pitch motions simultaneously in all of environmental conditions considered.


Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6496
Author(s):  
Jose Joaquin Sainz ◽  
Elías Revestido Herrero ◽  
Jose Ramon Llata ◽  
Esther Gonzalez-Sarabia ◽  
Francisco J. Velasco ◽  
...  

This paper presents the application of an linear quadratic gaussian (LQG) control strategy for concrete caisson deployment for marine structures. Currently these maneuvers are carried out manually with the risk that this entails. Control systems for these operations with classical regulators have begun to be implemented. They try to reduce risks, but they still need to be optimized due to the complexity of the dynamics involved during the sinking process and the contact with the sea bed. A linear approximation of the dynamic model of the caisson is obtained and an LQG control strategy is implemented based on the Kalman filter (KF). The results of the proposed LQG control strategy are compared to the ones given by a classic controller. It is noted that the proposed system is positioned with greater precision and accuracy, as shown in the different simulations and in the Monte Carlo study. Furthermore, the control efforts are less than with classical regulators. For all the reasons cited above, it is concluded that there is a clear improvement in performance with the control system proposed.


2011 ◽  
Vol 2-3 ◽  
pp. 1067-1070
Author(s):  
Hai Jun Xing ◽  
Shao Pu Yang ◽  
Yong Jun Shen

This research aims at the vibration control of vehicle seat suspension system. A three degree of freedom quarter vehicle model is used for semi-active control system in which a magnetorheological damper (MRD) is installed at the position between the vehicle body and the seat. A fully active linear quadratic regulator (LQR) control strategy is used to determine the optimized control force which is then matched by MRD to compute the semi-active control result. Computation result proves that semi-active control with MRD can alleviate the vehicle seat acceleration to improve ride comfort.


Author(s):  
Maide Bucolo ◽  
Arturo Buscarino ◽  
Luigi Fortuna ◽  
Mattia Frasca

AbstractLossless positive-real systems have been widely studied in the literature. They are systems in which the energy is entirely transferred between input and output. In this paper, new aspects related to the linear quadratic gaussian (LQG) control of lossless positive-real systems are reported including both the continuous-time and the discrete-time cases. Direct formulas for the calculation of the optimal gains will be introduced and the properties of the different structures of the LQG compensator obtained for the continuous-time and the discrete-time cases will be emphasized, also in view of designing positive-real LQG compensators. Numerical examples related to low-damped structures are also discussed to verify the possibility to design the LQG compensator on the basis of a lossless approximation.


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