The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In this paper the design of a nonlinear Hinfin controller for flexible joint robot (FJR) is presented. An approximate solution based on Taylor series expansion is considered for the Hamilton-Jacobi-Isaac (HJI) inequality. A two-degree-of-freedom controller combined of nonlinear Hinfin controller and inverse dynamics controller is proposed to tackle the regulation as well as tracking problem in FJR...
This paper presents a coordinated controller parameter adjusting method for boilers. The method includes constructing a simplified engineering boiler model and adjusting controller parameters with nonlinear constrained optimization. Because many control loops in the generation plants interfere with each other, the improvement in the control ability by the method is remarkable. Simulation results are...
EPS (electric power-assisted steering) system has been used to replace traditional hydronic power steering system in vehicles. In an EPS system, the assisting torque is from an electric motor for steering effort. The performance of an EPS system requires that the high frequency external disturbance in road reaction torque be attenuated so that the driver could feel comfortable - light and less vibration...
The communication channel delay can adversely affect performance and stability of bilateral teleoperation systems. This paper proposes a discrete-time linear quadratic Gaussian (LQG) controller that delivers a transparent stable response in the presence of constant communication latency. Different controllers are designed for each phase of operation, i.e. free motion and contact with rigid environments...
This paper presents a physical model of a spark ignition (SI) engine valve actuated by a voice coil actuator (VCA) and proposes a novel control strategy that achieves fast transitions and low seating velocities with high precision position control. The control strategy is based on applying two different pulse width modulated (PWM) voltages for transient and steady state performance. This novel switching...
In this paper, we propose a controller for a nonlinear system with an input constraint depending on the state. The proposed controller is based on Kidane's controllers. Then, if system has one input, we can tune optimality and robustness easily. We apply the proposed controller to single-link robot arm in order to verify the effectiveness of the proposed controller
This paper presents an efficient numerical method to obtain optimal PI tuning formulae for first order plus dead time processes. The design method is based on optimal load disturbance rejection. In order to obtain a robust controller, a constraint on the maximum sensitivity is used. In addition, the design method deals with setpoint response using a two degree of freedom structure. In order to show...
PID control schemes still continue to be widely used for most industrial control systems. This is mainly because PID controllers have simple control structures, and are simple to maintain and tune. However, it is difficult to find a set of suitable control parameters in the case of time-varying and/or nonlinear systems. For such a problem, the robust controller has been proposed. Although it is important...
In this paper, we discuss the design of multivariable motion controllers exploiting crosscouplings in the controller for open loop decoupling, disturbance rejection and feedforward decoupling. Using specific properties of motion systems, we illustrate that frequency response design methods can be extended to handle several multivariable control problems. Application to high performance motion systems...
We present nonlinear model predictive control design for a type of discrete-time nonlinear system. Range constraints are imposed on input, output and input rate. When states are not available, an observer based on Newton's algorithm is used to estimate all states. We also present an idea to improve robustness of the control system when plant is subjected to modeling uncertainties. By using past information,...
This paper discusses methodologies for designing limited lookahead supervisory controllers for a class of embedded systems that can be modeled as switching hybrid system (SHS). In the limited lookahead control approach, a limited forward horizon of possible behaviors is explored at each time step. The controller uses a cost function to determine the immediate action that moves the system toward the...
Today, marginal oil wells are being drilled and the operating margins for the bottom-hole well pressures during drilling are becoming narrower. This requires an improved control of the pressure balance between the reservoir pore pressure and the well bottom-hole pressure. In oil well drilling applications, the pressure is typically controlled manually by adjusting the choke valve. This paper proposes...
This paper presents the implementation of a two degree-of-freedom, high-precision, magnetic-levitation-based positioning system. The apparatus employs one permanent magnet linear synchronous motor and is constructed by Quanser Inc. The paper focuses on the design and testing of a nonlinear controller required for actuating the positioning system. The controller is based on feedback linearization and...
Static synchronous compensator (STATCOM) controls are known to enhance damping of a power system. The graphical loop-shaping procedure used in designing a robust STATCOM controller can be significantly improved by embedding some optimization procedure in it. In this article a particle swarm optimization (PSO) technique has been employed to find the fixed parameter robust controller parameters. PSO...
For linear systems with structured uncertainties, the unknown input fault detection observer (UIFDO) provides a robust diagnostic approach by decoupling the fault signals from the unknown input term. However, in real applications, detection performance of the UIFDO degrades seriously as nonlinearities become significant in a wide dynamic operating range. In this paper, a novel UIFDO design and the...
The paper presents the design of a new technique for induction motor control without using speed sensor. Here the discrete time control technique is used to design the controller for induction motor drive. The non-linear model of an induction motor is revisited here and linearized about an operating point to obtain a linear model for the same. A fast output sampling based controller is obtained by...
Complex systems like the F-16 when subject to actuator failures operate in nonlinear regimes and probably in the vicinity of bifurcation points. Therefore, in designing reconfigured controllers a designer must be aware of all bifurcation points, and their characteristics, within the impaired flight envelope. This work is the first step in that direction. The other limitations that were identified...
A scheme is presented for the integration of FDI functional units into control loops embedded in mechatronic systems. The core of this FDI scheme is to design the FDI functional units by making use of the available tracking control structure. The developed FDI scheme is applied to the air-intake control system of an SI-engine
This paper deals with fault detection observer design for linear time-invariant systems with unknown inputs. The design objective is set to minimize a combined performance index Hinfin/H- which means to achieve a good compromise between robustness to the disturbance and sensitivity to the fault. Hence, the fault detection observer is designed to detect the fault of smallest energy possible. In this...
This paper presents recent research results for feedback control design of motion systems. Two model-free approaches are investigated, that exploit the ease of experimentation which is typical for motion systems. One approach is data-based design of a linear feedback controller which realizes desired closed-loop sensitivity and complementary sensitivity transfer functions. These transfer functions...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.