Showing papers on "Open-loop controller published in 1973"

System for operating a boiling water reactor steam turbine power plant utilizing dual analog throttle pressure controllers

Abstract: A combined digital computer/analog control system for operating a boiling water reactor-steam turbine-power plant wherein one of two analog throttle pressure controllers is used for controlling the inlet and bypass valves. One of the pressure controllers is biased to provide a higher signal than the other; and such nonbiased controller is the one selected to control the valves. Each controller includes a pressure transducer, a summing device and amplifier, and a lead/lag circuit together with the appropriate power supply. A failure detection system is used to switch the controllers from automatic to manual when a predetermined combination of controller components becomes defective. Also, such system is so organized that a transducer failure for one controller causes the other controller to assume control regardless of whether such failure results in a higher or lower than proper signal.

Terminus controlled deep ocean manipulator

Abstract: The Naval Undersea Center has designed and built eleven different manipulative devices having up to seven independent functions. The most sophisticated of these devices is the Remote Unmanned Work System manipulator which is an all-purpose, seven function master-slave manipulator for light work at depths to 20,000 feet. The master or controller for this manipulator is a 3/4 scale analog. The operator grasps the "hand" or terminus of this device and moves it to a desired location and orientation; the hand of the manipulator or slave foliows to a corresponding position. Forces encountered by the manipulator are simulated in the controller giving the operator a form of force feedback. This type of terminus controller possesses several distinct advantages over exoskeletal "strap-on" manipulator controllers.

Voltage controller for synchronous electric machines

Abstract: An improved voltage controller for a synchronous electric machine of the type including a voltage controller including a controlled rectifier coupled thereto which is optimally matched to the parameters of the machine for its non-loaded condition. The improvement comprises a modulator coupled to the excitation winding and the controller of the machine, for generating a control signal which is proportional to the cosine of the load angle of the machine. The modulator modulates any output signal generated by the voltage controller of the machine according to the generated control signal. A voltage compensator coupled to the modulator generates a voltage compensation signal which is proportional to the current induced in the stator winding of the machine by the load applied thereto. The compensator also adds the compensation signal generated to the modulated output signal of the controller, which signals in combination form the voltage control input signal to the controlled rectifier of the machine and increase the current in the excitation winding of the machine in response to a load applied thereto, and thereby compensate for the reaction produced by the current induced in the stator winding of the machine by the load.

Multiplexed machine control apparatus

Abstract: A machine control apparatus has several machine members whose positions are to be controlled and has several servomechanism loops for controlling the members. Each servomechanism loop includes a controller, and switching is provided by which the inputs and outputs of the various controllers can be switched to control different ones of the movable machine members. Each controller has a data storage register for storing the instantaneous value of error signal of its servomechanism loop. Upon changeover of a particular member from one controller to another, the error signal data in the storage register of the outgoing controller is transferred to the error storage register of the incoming controller, so that the error signal data remains associated with the member being controlled, and no inaccuracies are introduced into the position of the controlled member.

Power control apparatus for direct-current lines

Abstract: A power control apparatus for controlling the power transmitted over a direct-current line connected between alternating-current lines is disclosed. The direct-current line is connected to the alternating-current lines by a converter and inverter respectively. The power control apparatus includes a converter firing unit connected to the converter, a converter current controller connected to the converter firing unit, and a power regulator connected to the converter current controller for supplying the same with a current reference value. An inverter firing unit is connected to the inverter and a voltage controller and an inverter current controller are provided for setting respective voltages on the direct-current line. One of these voltages is smaller than the other at a given time. A connection circuit connects the last-two mentioned controllers to the inverter firing unit so as to cause the controller corresponding to the one voltage to act upon the inverter firing unit at the given time. The inverter current controller has an input for receiving a current reference value smaller than the current reference value supplied to the converter current controller. The inverter current controller is configured to stabilize the current in the direct-current line to the current reference value supplied to the inverter current controller in a predetermined time interval. A remote transmission arrangement is connected between the power regulator and the inverter current controller for adjusting the current reference value supplied to the inverter current controller in response to a change in the power after the time interval has elapsed.

Multi-controller apparatus with controller limiting

Abstract: A process controlling apparatus includes a plurality of controllers wherein a selected controller regulates a single controlled element. The input signal of an amplifier in the unselected controller, is so limited by an associated limiting circuit that the output signal thereof does not deviate more than a predetermined percentage from the output signal of the selected controller which is regulating the controlled element.

Fluidic Control of a Hydrostatic Transmission in a Vehicle Propulsion System

Abstract: A vehicle propulsion system is considered which consists of an engine, hydrostatic transmission, and automatic controller. Control requirements are established for optimum or near optimum operation based on a steady-state performance index. Various controller classes are identified and a systematic method for synthesis of the “best” controller is outlined. A unique fluidic controller is discussed which adjusts the transmission ratio to maintain a specified engine speed-engine load relationship which maximizes overall system efficiency for a wide range of external load conditions.

A hybrid predictive controller with an adaptive fast model

Abstract: A hybrid predictive controller is proposed for control of second-order, or higher-order systems which can be approximated to second order. The proposed controller uses hybrid computation and is suitable for on-line computer controlled problems. A fast time second-order adaptive model of the system is used in which the gain and one of the equivalent time constants of the system is calculated instantaneously. As an example the proposed controller is used for control of the output voltage of a dc. generating system under load variations. Responses are compared when the controller uses a system model with fixed parameters and when the model is made adaptive.

A dead time process controller

Abstract: The control of systems containing pure dead time ele. ments has plagued the control engineer for many years. This thesis discusses a new controller developed by this writer which offers improved performance in first order processes dominated by a dead time element.