Showing papers on "Proportional control published in 1975"
Patent•
17 Mar 1975TL;DR: In this paper, an anti-skid type control system for automotive vehicles, apparatus for maintaining wheel slip in a region of values associated with a maximum coefficient of road friction is presented.
Abstract: In an anti-skid type control system for automotive vehicles, apparatus for maintaining wheel slip in a region of values associated with a maximum coefficient of road friction. Periodic modulation of the wheel brake torque in conjunction with wheel acceleration measurement are employed to determine the variation of the coefficient of road friction from an optimum value, while integral-plus-proportional control of the pulse modulation allows compensatory variation of the wheel torque and slip condition to a condition providing the optimum coefficient of road friction.
41 citations
TL;DR: A leaky-integrator element is proposed for the accommodation controller that appears to resolve the conflict between the proportional and integral controller models and also explains the experimental observations better than any of the existing models.
29 citations
TL;DR: In this article, a two-loop configuration is proposed for controlling a physical process with predominant time delay, where a fast auxiliary loop consisting of a proportional controller and a simple lag element, and a main (process) loop provided with another proportional controller operating on the process.
13 citations
Patent•
17 Mar 1975TL;DR: In this paper, a control system for a marine turbine power plant is described where the input signal to an electrohydraulic valve positioning circuit for ahead and astern turbines may be directly related to a desired valve position signal input set at a throttle lever.
Abstract: A control system for a marine turbine power plant is disclosed wherein the input signal to an electrohydraulic valve positioning circuit for ahead and astern turbines may be directly related to a desired valve position signal input set at a throttle lever. Hence, primary control is by a desired valve position signal. A speed feedback circuit is included and selectively applied to the desired valve position signal as a valve position trimming signal. Another input into the primary control or desired valve position is a malfunction proportional control signal which tracks boiler operation, shaft vibration and overspeed. The valve position signal is applied to the valve positioning circuit through a rate limiter which may be set at a fast, normal, or slow rate depending upon an input from a system interface board.
8 citations
TL;DR: In this article, two suboptimal control policies employing integral state feedback suitable for nonlinear systems and nonquadratic performance functionals have been proposed and necessary conditions are obtained using the variational approach to select optimally the time-invariant parameters for a general control structure of which the two sub-optimal policies proposed are particular cases.
Abstract: Two suboptimal control policies employing integral state feedback suitable for nonlinear systems and nonquadratic performance functionals have been proposed. Necessary conditions are obtained using the variational approach to select optimally the time-invariant parameters for a general control structure of which the two suboptimal policies proposed are particular cases. A numerical example is worked out and the results compared and discussed.
6 citations
TL;DR: In this article, an existing numerically controlled milling machine is fitted with cutter deflection transducers so that feedrate control of the process can be achieved by frequency-response analysis.
3 citations
Patent•
02 Jul 1975
TL;DR: In this article, the carrier wave exists only for the time between the trailing end of each control pulse and the leading end of the next control pulse, for the times between the first and the second control pulses, and for the periods between the last and the first control pulses.
Abstract: In a radio control system of the digital proportional control type in which a control signal whose period comprises a plurality of control pulses and a timing pulse is transmitted to control servomechanisms in response to the time width of each control pulse, the carrier wave exists only for the time between the trailing end of each control pulse and the leading end of the next control pulse, for the time between the trailing end of the timing pulse and the leading end of the first control pulse, and for the time between the leading end of the timing pulse and the trailing end of the last control pulse, in order to minimize consumption of the supply battery.
2 citations