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The paper deals with the development of the finite element method (FEM) model of piezoelectric beam elements, where the piezoelectric layers are located on the outer surfaces of the beam core, which is made of functionally graded material. The created FEM model of piezoelectric beam structure is reduced using the modal truncation method, which is one of model order reduction (MOR) method. The results obtain from reduced state-space model are compared with results obtain from finite element model. MOR state-space model is also used in the design of the linear quadratic regulator (LQR). Created reduced state-space model with feedback with the LQR controller is analysed and compared with the results from FEM model.

The paper presents the concept of controlling the designed optoelectronic scanning and tracking seeker. The above device is intended for the so-called passive guidance of short-range anti-aircraft missiles to various types of air maneuvering targets. In the presented control method, the modified linear-quadratic regulator (LQR) and the estimation of input signals using the extended Kalman filter (EKF) were used. The LQR regulation utilizes linearization of the mathematical model of the above-mentioned seeker by means of the so-called Jacobians. What is more, in order to improve the stability of the seeker control, vector selection of signals received by the optoelectronic system was used, which also utilized EKF. The results of the research are presented in a graphical form. Numerical simulations were carried out on the basis of the author’s own program developed in the programming language C++.

Se propone una solución mediante un sistema de control de robot móvil tipo tráiler aplicado a una empresa que se encarga del transporte de material, y se demuestra que es una solución aplicable y viable. Se definió un modelo matemático que consiste en integrar dos técnicas de control: lineal LQR y lógica difusa. Se muestran resultados favorables del sistema de control y seguimiento de trayectoria, y se señalan las mejoras que se tienen al integrar ambas técnicas de control y que el sistema es capaz de responder correctamente a fin de guiar al robot por cualquier tipo de trayectoria.

International audience; Rollover of heavy vehicle is an important road safety problem worldwide. Although rollovers are relatively rare events, they are usually deadly accidents when they occur. The roll stability loss is the main cause of rollover accidents in which heavy vehicles are involved. In order to improve the roll stability, most of modern heavy vehicles are equipped with passive anti-roll bars to reduce roll motion during cornering or riding on uneven roads. However these may be not sufficient to overcome critical situations. This paper introduces the active anti-roll bars made of four electronic servo-valve hydraulic actuators, which are modelled and integrated in a yaw-roll model of a single unit heavy vehicle. The control signal is the current entering the electronic servo-valve and the output is the force generated by the hydraulic actuator. The active control design is achieved solving a linear optimal control problem based on the Linear Quadratic Regulator (LQR) approach. A comparison of several LQR controllers is provided to allow for tackling the considered multi-objective problems. Simulation results in frequency and time domains show that the use of two active anti-roll bars (front and rear axles) drastically improves the roll stability of the single unit heavy vehicle compared with the passive anti-roll bar.

This article presents a non-linear control system for a robotic arm that will be used for pipeline reparation. It starts with the mechanical description of the arm, its parameters and how the arm will repair the pipelines. This arm needs a control law that is non-linear. The proposed control strategy is obtained through the interpolation of classic feedback quadratic controllers that are computed for each operation point in a trajectory. This design is based on a numerical model that avoids computing an analytical model which is very useful for this kind of application. The technique is validated through simulations.

In this paper, the authors propose an optimal controller for the ship motion. Firstly, the model and dynamic equations of the ship motion are presented. Based on the model of the ship motion, the authors build the linear quadratic regular algorithm-based control system of ship motion to minimize the error between the desired trajectory and the response trajectory. The task of the controller is to control the trajectory of the ship to coincide with the desired trajectory. The ship model and controller are built to investigate the system quality through Matlab-Simulink software. The results show that the quality of the hold control system is very high. The trajectory of a ship always follows the desired trajectory with very small errors.

Purpose – The growing use of small unmanned rotorcraft in civilian applications means that safe operation is increasingly important. The purpose of this paper is to investigate the fault tolerant properties to faults in the actuators of an C 1 adaptive controller for a quadrotor vehicle. Design/methodology/approach – C 1 adaptive control provides fast adaptation along with decoupling between adaptation and robustness. This makes the approach a suitable candidate for fault tolerant control of quadrotor and other multirotor vehicles. In the paper, the design of an C 1 adaptive controller is presented. The controller is compared to a fixed-gain LQR controller. Findings – The C 1 adaptive controller is shown to have improved performance when subject to actuator faults, and a higher range of actuator fault tolerance. Research limitations/implications – The control scheme is tested in simulation of a simple model that ignores aerodynamic and gyroscopic effects. Hence for further work, testing with a more complete model is recommended followed by implementation on an actual platform and flight test. The effect of sensor noise should also be considered along with investigation into the influence of wind disturbances and tolerance to sensor failures. Furthermore, quadrotors cannot tolerate total failure of a rotor without loss of control of one of the degrees of freedom, this aspect requires further investigation. Practical implications – Applying the C 1 adaptive controller to a hexrotor or octorotor would increase the reliability of such vehicles without recourse to methods that require fault detection schemes and control reallocation as well as providing tolerance to a total loss of a rotor. Social implications – In order for quadrotors and other similar unmanned air vehicles to undertake many proposed roles, a high level of safety is required. Hence the controllers should be fault tolerant. Originality/value – Fault tolerance to partial actuator/effector faults is demonstrated using an C 1 adaptive controller.

International audience; Rollover is a very serious problem for heavy vehicle safety, which can result in large financial and environmental consequences. In order to improve roll stability, most of modern heavy vehicles are equipped with passive anti-roll bars to reduce roll motion during cornering or riding on uneven roads. This paper introduces the active anti-roll bars designed by finding an optimal control based on a linear quadratic regulator (LQR). Four electronic servo valve hydraulic dampers are modelled and applied on a yaw roll model of a single unit heavy vehicle. The control signal is the current entering the electronic servo valve and the output of this actuator is the damping force generated by the hydraulic damper. Simulation results are obtained and compared in three different situations: without anti-roll bars, with passive anti-roll bars and with active anti-roll bars. It is shown that the use of two active (front and rear) anti-roll bars drastically improves the behaviour of the single unit heavy vehicle.

There has been a significant increase in attention toward designing smart structures and vibration control of structures in recent decades, and numerous methods and algorithms have been developed and experimentally investigated. However, the majority of these studies used the shear frame models to represent structures. Since the simplified models do not reflect the realistic behavior of those structures with irregularity in plan and elevation, the traditional methods for designing an optimal control that guarantees a desirable performance is impossible. In this study, the behavior of a 10-story irregular steel frame building is investigated with and without controlling systems. Two pairs of eccentrically placed MR dampers on each story are used in order to mitigate the coupled translational–torsional vibration. The controlling forces are determined using active, passive-off, passive-on, and clipped optimal controls based on the linear quadratic regulator (LQR) algorithm. The results demonstrate that using pairs of magneto-rheological (MR) dampers with an appropriate distance on lower story levels significantly reduces the inter-story drifts for the corner columns, as well as the roof displacements and accelerations.

This paper, describes a LQG and LQR robust controller for the lateral and longitudinal flight dynamics of an aircraft control system. The controller is used in order to achieve robust stability and good dynamic performance against the variation of aircraft parameters. The application of the proposed LQG and LQR robust control scheme is implemented through the simulation. The proposed robust controller for aircraft stability is designed using Matlab/Simulink program. Simulation results confirm the performance of the proposed controller for aircraft control system. Since the time of its introduction, the Kalman filter has been the subject of extensive research and application, particularly in the area of autonomous or assisted navigation. For example, to determine the velocity of an aircraft or sideslip angle, one could use a Doppler radar, the velocity indications of an inertial navigation system, or the relative wind information in the air data system. Rather than ignore any of these outputs, a Kalman filter could be built to combine all of this data and knowledge of the various systems dynamics to generate an overall best estimate of pitch, roll and sideslip angle.

In this paper, the control of the stationary response of a quarter car model to random road excitation with a Magnetorheological (MR) damper as a semi-active suspension device is considered. The MR damper is a hypothetical analytical damper whose parameters are determined optimally using a multi-objective optimization technique Non-dominated Sorting Genetic Algorithm II (NSGA II). The hysteretic behaviour of the MR damper is characterized using Bingham and modified Bouc-Wen models. The multi-objective optimization problem is solved by minimizing the difference between the root mean square (rms) sprung mass acceleration, suspension stroke and the road holding responses of the quarter car model with the MR damper and those of the active suspension system based on linear quadratic regulator (LQR) control with the constraint that the MR damper control force lies between �5 percent of the LQR control force. It is observed that the MR damper suspension systems with optimal parameters perform an order of magnitude better than the passive suspension and perform as well as active suspensions with limited state feedback and closer to the performance of fully active suspensions. � 2012 Elsevier Ltd. All rights reserved.

With the aim of developing multiple input and multiple output (MIMO) coupling systems with a redundant parallel adjustment mechanism on the deployable antenna panel, a structural control integrated design methodology is proposed in this paper. Firstly, the modal information from the finite element model of the structure of the antenna panel is extracted, and then the mathematical model is established with the Hamilton principle; Secondly, the discrete Linear Quadratic Regulator (LQR) controller is added to the model in order to control the actuators and adjust the shape of the panel. Finally, the engineering practicality of the modeling and control method based on finite element analysis simulation is verified.

Magnetic levitation is a powerful phenomenon which, if correctly controlled allows frictionless relative motion between two bodies. Active Magnetic Bears use this characteristic to allow the rotation between stator and rotor without contact, but typically, the small airgap does not allow an active dumping of the mechanical vibrations. This paper presents a new large airgap magnetic bearing that allows to add dumping features thanks to a dedicated control. A simplified analytical model has been introduced and experimental results are presented.

A Stewart platform is a well-known mechanism which can be used for a wide variety of vibration control problems. In this paper, an LQR controller for a Stewart platform prototype is proposed which, combined with proportional derivative gain matrix, achieves a good performance when compared to the classical PID control system. By testing some trajectories, we observe that the tracking error between the actual and pre-established trajectories is smaller when applying the controller designed in this work. The final purpose is not only the implementation of this kind of control to a real Stewart platform constructed at the Universitat Politecnica de Catalunya (UPC) by our research group, but its application to other similar parallel robots.

The primary function of a vehicle suspension system is to isolate the road excitations experienced by the tyres from being transmitted to the passengers. In this paper, a suitable optimizing technique is applied at design stage to obtain the suspension parameters of a passive suspension and active suspension for a passenger car which satisfies the performance as per ISO 2631 standards. A number of objectives such as maximum bouncing acceleration of seat and sprung mass, root mean square (RMS) weighted acceleration of seat and sprung mass as per ISO2631 standards, jerk, suspension travel, road holding and tyre deflection are minimized subjected to a number of constraints. The constraints arise from the practical kinetic and comfortability considerations, such as limits of the maximum vertical acceleration of the passenger seat, tyre displacement and the suspension working space. The genetic algorithm (GA) is used to solve the problem and results were compared to those obtained by simulated annealing (SA) technique and found to yields similar performance measures. Both the passive and active suspension systems are compared in time domain analyses subjected to sinusoidal road input. Results show passenger bounce, passenger acceleration, and tyre displacement are reduced by 74.2%, 88.72% and 28.5% respectively, indicating active suspension system has better potential to improve both comfort and road holding.