Showing papers on "Open-loop controller published in 1971"

Adaptive controller having optimal filtering

Abstract: A self-adaptive controller for use in a control process for providing ordered changes in a manipulated process variable in response to measured changes in a controlled process variable having means for using measured and predicted values of the controlled variable to obtain an estimated value of the controlled variable which estimated value is used via a self-adaptive controller to determine the change in manipulated variable. The controller is described with reference to a paper manufacturing process for controlling the basis weight and moisture content of a continuous web of paper.

Two-Level Control of Interconnected Power Plants

Abstract: A two-level controller for interconnected power plants is discussed. Each plant has a first level local optimal or suboptimal controller. The second level of control is an intervention control performed by a central co-ordinator. If a sudden system disturbance causes the system angular acceleration to exceed preset tolerances a priority interrupt to the central co-ordinator initiates intervention control. Angular velocity deviations of all plants are transmitted to the co-ordinator. This data is used to generate coefficient data for each plant. On receiving its coefficient data, each plant generates a local second-level intervention control which augments first level local control.

Apparatus for limiting the rate of rise of current in a multi-loop motor control system

Abstract: Described is a system for limiting the rate of rise of current in a multi-loop cascaded motor control configuration by means of a ramp function generator connected to the output of a motor controller, for example, a speed controller, whose output acts as a reference to a current loop.

Predictive position feedback controller for web guide control system

Abstract: An electronic controller for a process control system for use with a bi-directional single speed actuating device wherein the controller includes a proportional plus integral mode with predictive position feedback.

Electrically synchronized controllers

Abstract: A multiple hand controller system is disclosed having redundant systems for synchronizing the movements of the hand controllers. In one embodiment, the hand controller system comprises a pair of movable hand controllers. Each hand controller is coupled to a movable ground point to be movable in two modes. The first mode is where the hand controller moves with respect to its ground point. The second mode is where the hand controller moves as a unit with its ground point. The synchronizing system comprises two sets of components. Each set includes an actuator for varying the location of the ground point of one hand controller. Each set includes a first sensor for sensing the first mode of movement for one hand controller and generating an input signal porportional to this movement. The input signal from the first sensor of each set is fed, through a summing amplifier, to the actuator of the other set. A second sensor is also provided for monitoring the movement of each ground point and generating a signal proportional to this movement. The signal from each second sensor is fed back to the summing amplifier controlling its respective actuator to be algebraically summed with the input signal from the first sensor to generate an output signal. This output signal is fed to the respective actuator to command the actuator to move the ground point location of its connected hand controller an amount representative of the movement of the other hand controller. This cross synchronization enables the movement of one hand controller in the first mode to affect a representative movement of the other hand controller in the second mode.

Feedback control system with digital control elements

Abstract: A feedback control system having a digital steering controller connected to be directly responsive to a command signal and to at least one other input signal, and providing a train of first output signals received by a simulator, constructed for simulating operation and response of a controlled system. At least one output signal of the simulator is the other input signal of the steering controller, and is additionally fed to a digital error controller together with an output signal of the controlled system, that corresponds functionally to the output signal of the simulator. The digital error controller forms an error signal and provides an output that is combined with the output of the steering controller and fed to the controlled system.

A new technique for closed loop control of discrete stochastic nonlinear systems

Abstract: A new approach for optimum control of discrete stochastic nonlinear systems is developed from practical engineering assumptions. Systems amenable to this new approach include optimum guidance and navigation systems for space and terrestrial vehicles, optimum closed-loop process controllers, and optimum controllers for systems with unknown parameters. The solution is obtained by expansion of the stochastic cost function in a power series around a deterministic trajectory with the assumption of linear perturbation estimation and control about that trajectory. Optimization of the expanded cost function gives necessary conditions dependent on the covariance matrices and the deterministic portion of the cost. When the necessary conditions are solved, a set of open-loop controls, perturbation controller gains, and perturbation estimator gains are obtained that can be precomputed and implemented into the system.

A hybrid controller for pseudo-optimal feedback control of nonlinear systems:

Abstract: * Present address: Department of Chemical and Nuclear Engineering University of Cincinnati Cincinnati, Ohio 45221 implementation of optimal control theory concerns the general multidimensional nonlinear system for which usually only an optimal open-loop or programmed control can be obtained. Such a control is truly optimal only if the system follows the precalculated optimal trajectory. In a real situation, the system will usually not follow such a trajectory because (a) a mathematical-model approximation never perfectly represents the real-world process and (b) unexpected disturbances entering the loop initiate upsets. For these reasons it is desirable to have a closed-loop control algorithm that is a function of the actual state of the system.