Abstract: We propose a new feedback controller architecture. The distinguished feature of our new controller architecture is that it shows structurally how the controller design for performance and robustness may be done separately which has the potential to overcome the conflict between performance and robustness in the traditional feedback framework. The controller architecture includes two parts: one part for performance and the other part for robustness. The controller architecture works in such a way that the feedback control system can be solely controlled by the performance controller when there is no model uncertainties and external disturbances and the robustification controller can only be active when there are model uncertainties or external disturbances.

Abstract: In web transport systems, the main concern is to control independently speed and tension in spite of perturbations such as radius variations and changes of setting point. Multivariable controllers including gain scheduling have already given good results in that sense. Nevertheless, in these control techniques, tracking properties and perturbation rejection are interdependent and cannot be specified separately. In this paper, we present multivariable H/sub /spl infin// robust control with two degrees of freedom (2DOF) and gain scheduling applied to winding systems. Three controller structures are considered: a global controller, a semidecentralized controller, and a semidecentralized controller with overlapping. Simulation results are given, based on a nonlinear model identified on an experimental bench. In each case, the 2DOF controller is compared to the classical 1DOF controller. The 2DOF approach allows improving significantly disturbance rejection while reducing coupling between tension and velocity.

Abstract: A ripple-mode controller provides reliable operation in multi-phase power supply circuits, over a variety of operating conditions. Cross-phase blanking allows the controller to preserve the desired phase relationship between the switching pulses its provides to the different output phases, and permits the controller to operate each output phase at nearly 100% duty cycles. Active current sharing compliments blanking operations by adjusting the width of switching pulses the controller provides to one or more of the output phases based on detecting load current imbalances between the different output phases. With active current sharing, the controller prevents one or more output phases from carrying excessive portions of the load current. Further complimenting its operation, the controller may include virtual ripple generation to increase the noise immunity of its ripple-mode regulation.

Abstract: This paper presents a new approach toward the optimal design of a hybrid proportional-integral-derivative (PID) controller applicable for controlling linear as well as nonlinear systems using genetic algorithms (GAs). The proposed hybrid PID controller is derived by replacing the conventional PI controller by a two-input normalized linear fuzzy logic controller (FLC) and executing the conventional D controller in an incremental form. The salient features of the proposed controller are as follows: (1) the linearly defined FLC can generate nonlinear output so that high nonlinearities of complex systems can be handled; (2) only one well-defined linear fuzzy control space is required for both linear and nonlinear systems; (3) optimal tuning of the controller gains is carried out by using a GA; and (4) it is simple and easy to implement. Simulation results on a temperature control system (linear system) and a missile model (nonlinear system) demonstrate the effectiveness and robustness of the proposed controller.

Abstract: A system and method for operating a distributed control network (fig3) for irrigation management The system incorporates several irrigation controllers (15) wherein each of the controllers (15) can transmit, receive and respond to commands initiated by any device or satellite controller (15) on the network (fig3), a communication bus (23) that is connected to the controllers (15), a central computer (25) that is connected to the bus (23), several sensing devices (21) that are connected to each controller (15), and several sprinkler valves (17) that are connected to each controller (15) The controllers (15) can be operated in local mode via a user interface and in a remote mode via a wireless connection (27) The controllers (15) are capable of monitoring and acknowledging the commands that are transmitted on the bus (23)

Abstract: The paper addresses the problem of controlling the joints of a flexible joint robot with a state feedback controller and proposes a gradual way of extending such a controller towards the complete decoupling of the robot dynamics. The global asymptotic stability for the state feedback controller with gravity compensation is proven, followed by some theoretical remarks on its passivity properties. By proper parameterization, the proposed controller structure can implement a position, a stiffness or a torque controller. Experimental results on the DLR lightweight robots validate the method.

Abstract: This paper includes an application of layered artificial neural network controller to study the load-frequency control problem in a power system. The control scheme guarantees that steady state error of frequencies and inadvertent interchange of tie-lines are maintained in a given tolerance limitation. The proposed control has been designed for a three-area interconnected power system such that two areas include steam turbines and the other area includes a hydro turbine. Only one artificial neural network (ANN) controller, which controls the inputs of each area in the power system together, is considered. In the study, a back propagation-through-time algorithm is used as a neural network learning rule. The performance of the power system is simulated by using a conventional integral controller and ANN controller, separately. By comparing the results for both cases, the performance of an ANN controller is better than conventional controllers.

Abstract: This paper presents the stability analysis of a fuzzy-model-based control system consisting of a nonlinear plant and a nonlinear state feedback controller and the design of the nonlinear gains of the controller. The nonlinear plant is represented by a fuzzy model having p rules. A nonlinear state feedback controller is designed to close the feedback loop. Under this design, the stability condition is reduced to p linear matrix inequalities. An application example on stabilizing a mass-spring-damper system will be given.

Abstract: Zak and Hui (1993) proposed a sliding mode controller for linear multiple-input-multiple-output (MIMO) systems using static output feedback. The author's previous paper (1996) provides an improvement of the output feedback controller of Zak-Hui for a class of linear single-input-single-output (SISO) systems that eliminated two important limitations: 1) system uncertainties must be bounded by the system output; and 2) a requirement of a matrix inequality. The controller developed previously can guarantee global closed-loop stability. This paper extends the previous results to linear MIMO systems. It is emphasized that the proposed MIMO controller yields global closed-loop stability whereas the one in Zak-Hui can only guarantee local stability. An application of the proposed MIMO controller to an aircraft model is included to show the effectiveness of the method.

Abstract: An integrated unit controller/human-machine interface is disclosed which incorporates high-speed redundant control, sequence of events, supervisory control and data acquisition, alarm handling, trending & historian, process graphics and “open” communications in a compact form factor enclosure (the front panel less than 5×6 inches). The unit controller is composed of two primary hardware elements: the controller module (single or redundant) and the palm type computers (P/PC)-based human-machine interface (HMI) with touch screen. The controller covers a wide span of applications, from single process unit control to networked multi-unit management.

Abstract: A control-oriented linear model was constructed for an electromagnetic camless valvetrain (EMCV) based on a gray-box approach that combines mathematical modeling and system identification. An inner-loop feedback stabilizing controller and a cycle-to-cycle repetitive learning feedforward controller were designed for the EMCV to meet the quiet-seating requirement. The performance of this control system is demonstrated by experimental results.

Abstract: In this paper, a steady-state model of a VSC (voltage source converter) based HVDC system has been developed. According to this model, the corresponding relationship between the two controlling and the two controlled variables of the VSC is determined. Furthermore, a nonlinear control strategy combining an inverse model controller with a PI controller is proposed, and a nonlinear compensation method is adopted for the DC voltage PI controller. Digital simulation shows the validity of the established steady-state model and the feasibility of the proposed control strategy.

Abstract: A redundant controller data storage system having a hot insertion system and method is described. In one aspect, the method of hot inserting a controller in a redundant controller system includes configuring a first controller to include a first memory, a task processor and a system operation processor. The first memory includes a first memory image. The redundant controller system is operated via the first controller. The system operation commands are processed via the system operation processor. A second controller including a second memory, is inserted into the redundant controller system. Background tasks are processed during the processing of system operation commands via the first controller using the task processor, including copying the first memory image to the second memory.

Abstract: The present invention relates to a wireless home automation system having controllers for controlling a broad variety of functions via two-way communication with a plurality of devices More specifically, the invention relates to sharing information related to the system between controllers, eg by updating a second controller with the newly learned information of a first controller, or by replicating a controller by making a second controller a complete copy of a first controller The information can be shared by generating and transmitting, with a first controller, a list of device identifiers of devices controlled by the first controller to a second controller The list is received by the second controller and stored in a memory of the second controller dedicated to store device identifiers of devices controlled by the second controller This function proves advantageous when new controllers are introduced or if a controller is lost, worn out, or destroyed

Abstract: : This paper presents a pronking controller for our six-legged robot RHex. Development of the controller begins with a passive-dynamics approach, ensuring that the robot is naturally suited to running. Running with flight phase is then achieved using only proprioceptive (joint angle sensing only) feedback for touchdown detection and for tracking fixed joint reference trajectories. Body pitch oscillation is attenuated by means of an open loop leg speed change during stance. The robot achieves speeds of about two body lengths per second with a specific resistance of 1.85.

Abstract: The design problem of proportional and proportional-plus-integral (PI) controllers for nonlinear systems is studied. First, a Takagi-Sugeno fuzzy model with parameter uncertainties is used to approximate the nonlinear systems. Then a numerically tractable algorithm based on the technique of iterative linear matrix inequalities is developed to design a proportional (static output feedback) controller for the robust stabilization of the system in Takagi-Sugeno fuzzy model. Thirdly, we transform the problem of PI controller design to that of proportional controller design for an augmented system and thus bring the solution of the former problem into the configuration of the developed algorithm. Finally, the proposed method is applied to the design of robust stabilizing controllers for the excitation control of power systems. Simulation results show that the transient stability can be improved by using a fuzzy PI controller when large faults appear in the system, compared to the conventional PI controller designed by using a linearization method around the steady state.

Abstract: A method and apparatus for providing an active standby control system comprising the steps of providing a first and second controller, each controller having an operating state. Each controller is operably connected to a network. Assigning a network identifier, i.e., Internet Protocol, Media Access Control address, etc., to each controller and sensing the operating state of each controller. The network identifier of each controller is determined by the operating state of each respective controller.

Abstract: This note proposes a systematic approach for the static output feedback control design for discrete time linear systems. It is shown that if the open loop system satisfies some particular structural conditions, a static output feedback gain can be calculated easily, using a formula only involving the original system matrices. Among the conditions the system has to satisfy, the stronger relies on a minimum phase argument. Square and nonsquare systems are considered.

Abstract: This paper presents a sliding-mode controller with integral compensation for a magnetic suspension balance beam system. The control scheme comprises an integral controller which is designed for achieving zero steady-state error under step disturbances, and a sliding-mode controller which is designed for enhancing robustness under plant uncertainties. A procedure is developed for determining the coefficients of the switching plane such that the overall closed-loop system has stable eigenvalues. A proper continuous design signal is introduced to overcome the chattering problem. The performance of the balance beam control system is illustrated by simulation and experimental results showing that the proposed integral sliding-mode controller method is effective under external step disturbances and input channel parameter variations.

Abstract: Input shaping is a simple and eVective method for reducing the residual vibration when positioning lightly damped systems, and it remains an active research area. In this paper, a continuous and diVerentiable function is introduced to dee ne the desired motion, and then the input is shaped by inverse dynamic analysis. In the proposed method the only parameter that needs to be dee ned is the output speed, which is limited only by the physical constraints of the drive system. The calculation of an optimum speed is demonstrated by simulation examples. It is also shown that, under certain circumstances, the process can be further simplie ed and the need for inverse dynamics is eliminated.

Abstract: A novel architecture for integrating neural networks with industrial controllers is proposed, for use in predictive control of complex process systems. In the proposed method, a conventional PI controller is used to control the process. In addition, a recurrent neural network is used in the form of a multistep-ahead predictor to model the process dynamics. The parameters of the PI controller are tuned by a backpropagation-through-time like approach using "parallel learning" to achieve acceptable regulation and stabilization of the controlled process. The advantage of such a formulation is the effective online adaptation of the controller parameters while the process is in operation, and the tracking of the different process operating regimes and variations. The proposed method is used in the stabilization and transient control of U-tube steam generator water level. The proposed predictive controller stabilizes the process and improves its transient performance over the entire operating range.

Abstract: A novel neural network (NN) backstepping controller is modified for application to an industrial motor drive system. A control system structure and NN tuning algorithms are presented that are shown to guarantee the stability and performance of the closed-loop system. The NN backstepping controller is implemented on an actual motor drive system using a two-PC control system developed at the authors' university. The implementation results show that the NN backstepping controller is highly effective in controlling the industrial motor drive system. It is also shown that the NN controller gives better results on actual systems than a standard backstepping controller developed assuming full knowledge of the dynamics. Moreover, the NN controller does not require the linear-in-the-parameters assumption or the computation of regression matrices required by standard backstepping.

Abstract: The self-organising fuzzy controller is an extension of the rule-based fuzzy controller with an additional learning capability. The self-organising fuzzy (SOF) is used as a master controller to readjust conventional PID gains at the actuator level during the system operation, copying the experience of a human operator. The application of the self-organising fuzzy PID (SOF-PID) controller to a 2-link non-linear revolute-joint robot-arm is studied using path tracking trajectories at the setpoint. For the purpose of comparison, the same experiments are repeated by using the self-tuning controller subject to the same data supplied at the setpoint. For the path tracking experiments, the output trajectories of the SOF-PID controller followed the specified path closer and smoother than the self-tuning controller.