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    <title>Transport Research International Documentation (TRID)</title>
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Transport Research International Documentation (TRID)</title>
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      <title>THE DEVELOPMENT OF AUTOMATIC CONTROL SYSTEMS FOR HYDROFOIL CRAFT</title>
      <link>https://trid.trb.org/View/20313</link>
      <description><![CDATA[The development of hydrofoil craft has been accomplished by two schools of endeavours.  One school has pursued the surface-piercing principle whereby the craft is stabilised by variable submerged area.  The other devotees have worked on various means of controlling the incidence angle.  This paper is intended to bring into perspective how this latter school has progressed from pitching the craft to change the foil angle of attack, through unique and innovative mechanical means of controlling incidence to the rather sophisticated electronic automatic control systems of today. Such a paper is not complete without discussing the methods used to sense wave and craft motions and the methods employed to compute the proper control to the foil surface. Finally, the paper concludes by describing what now appears to be a most promising future control system based on digital computer technology.]]></description>
      <pubDate>Mon, 16 Aug 1982 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/20313</guid>
    </item>
    <item>
      <title>IMPROVEMENT OF CONTROL BY SPECIAL DEVICES</title>
      <link>https://trid.trb.org/View/161728</link>
      <description><![CDATA[The paper discusses hydrodynamic devices for improving manoeuvring and control.  Two hydrodynamic concepts are shown to be of practical significance for large craft: control of hydrofoil lift independent of incidence, and deflection of the propulsion jet through a large angle by means of a simple hydrofoil.  Lift control independent of incidence is illustrated by the jet flap and the trailing edge rotating cylinder.  Improved deflection of the propeller slipstream involves extending the rudder stall angle, and it is shown how this may be achieved by fitting the rudder with a leading edge rotating cylinder.]]></description>
      <pubDate>Wed, 15 Apr 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/161728</guid>
    </item>
    <item>
      <title>SAS GOES DIGITAL</title>
      <link>https://trid.trb.org/View/92107</link>
      <description><![CDATA[This paper is intended to deal with a system able to augment the seakeeping ability and thus the comfort of an advanced marine vehicle, that is, a hydrofoil.  Design of a new controller, called tentatively SAS MK2, the preprototype of which is presently on the test bench for static and compatibility test has taken into consideration all the constraints of the environment in which it has to operate. Although no final test has been carried out at this stage, simulation work shows that the new controller will improve the seakeeping capability of the hydrofoil, and in turn, will improve the passenger comfort.  The trend in going digital is not dictated by purely research needs, but instead responds to a need of having a more intelligent controller.]]></description>
      <pubDate>Sat, 15 Sep 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/92107</guid>
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      <title>HYDRODYNAMIC LOADING COEFFICIENTS FOR THE AGEH-1 MAIN STRUT-POD-FOIL SYSTEM AS DERIVED FROM THE 1975 FLAP INCIDENCE CONTROL EXPERIMENT</title>
      <link>https://trid.trb.org/View/82855</link>
      <description><![CDATA[As part of an investigation into minimizing control power requirements for hydrofoil craft, a technique has been developed for obtaining complete hydrodynamic lift and moment characteristics of a flapped hydrofoil from equilibrium data obtained in flap incidence control experiments with a freely pivoting foil. This method employs a simple mathematical model and various crossplots of the data to separate the effects of camber, foil incidence angle, and flap angle using a minimum amount of data. Existing model data for the AGEH-1 main strut-pod-foil system under subcavitating conditions have been analyzed by this method, and effects of depth and velocity are described. Velocity effects were attributed to air and/or water flow out of the pod. Relatively high values of flap lift effectiveness (0.3 to 0.4) were obtained. Centers of pressure (lines of action) for lift due to camber, angle of attack, and flap angle are presented. Recommendations are given for improving the accuracy of the measurement and analysis techniques. (Author)]]></description>
      <pubDate>Sat, 26 May 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/82855</guid>
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      <title>OPTIMAL CONTROL OF HYDROFOIL SHIP LATERAL DYNAMICS</title>
      <link>https://trid.trb.org/View/78167</link>
      <description><![CDATA[A linear mathematical model of the lateral dynamics of a foilborne vessel equipped with a fully submerged hydrofoil system is developed.  As such a vessel is inherently dynamically unstable it requires an automatic control system to provide motion stabilization.  Using the techniques of modern control theory, an optimal controller is designed for a hypothetical ship moving through beam seas at a speed of 50 knots.  The performance index used in this application is a functional of both the lateral acceleration experienced in the wheelhouse and the hydraulic power required by the actuators.  Because of the large number of feedbacks required, an optimal controller may not be practical.  This leads to the consideration of an adequate suboptimal controller which employs a reduced number of feedbacks.  The performance of the final design is evaluated in beam seas using a time domain simulation.  As a final step, the analysis is extended to include the effect of uncertainty in the sensor measurements, and a Kalman filter is designed to generate the estimates of the state variables required by the control system.]]></description>
      <pubDate>Sat, 03 Feb 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/78167</guid>
    </item>
    <item>
      <title>INSTRUMENT FAULT DETECTION</title>
      <link>https://trid.trb.org/View/80683</link>
      <description><![CDATA[The dedicated observer scheme (DOS) for detecting incipient instrument faults by functional redundancy is applied to a simulation of the lateral axis control system of a hydrofoil boat.  Observer designs and detection logic are found for which 14 separate instrument faults are detected without false alarms.  The scheme is shown to be robust with respect to variations in two significant physical parameters.]]></description>
      <pubDate>Sat, 13 Jan 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/80683</guid>
    </item>
    <item>
      <title>HYDROFOIL PERFORMANCE IN ROUGH WATER</title>
      <link>https://trid.trb.org/View/16039</link>
      <description><![CDATA[Beginning with the history of speeds achieved by hydrofoils worldwide, this account deals with recent results of the U.S. Navy Advanced Development Program.  This program has gathered information on platform performance and operational demonstrations from the HIGH POINT (PCH-1).  PLAINVIEW (AGEH-1), FLAGSTAFF (PGH-1) and TUCUMCARI (PGH-2).  Recent developments in hydrofoil platform technologies cover automatic control systems, propulsion and auxiliary machinery, strut-foil, and hull subsystems.  Operations cover total operational and foilborne times, transit distances, debris collisions, mission equipment demonstrations, and underway transfer operations.  A discussion of work leading to future larger and faster hydrofoils concludes the account.]]></description>
      <pubDate>Sun, 07 May 1978 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/16039</guid>
    </item>
    <item>
      <title>INVESTIGATION OF LONGITUDINAL CONTROL SYSTEM FOR A SMALL HYDROFOIL BOAT</title>
      <link>https://trid.trb.org/View/47272</link>
      <description><![CDATA[An analysis of a hydromechanical system for longitudinal control of a small hydrofoil boat is presented.  The system incorporates height and acceleration sensors operating flaps on the foils through a mechanical linkage.  Effects of some of the system parameters on the stability and response to waves are shown.  The results indicate that the system is capable of providing adequate stability, but the response to stern waves at low frequencies is larger than desired.]]></description>
      <pubDate>Tue, 26 Oct 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/47272</guid>
    </item>
    <item>
      <title>H.890 EXPERIMENTAL HYDROFOIL CRAFT</title>
      <link>https://trid.trb.org/View/46200</link>
      <description><![CDATA[Part I of this paper deals with the control system. After an outline of the control principles underlying the system, an account is given of its craftborne application with special attention to the role of simulation studies. Part II summarizes the hydrodynamic behavior and performance of an H.890 canard configuration craft as evidenced by calculations, model and full-scale tests. Finally, an attempt is made to crystallize project findings and to predict their implications for the design of operational hydrofoil craft.]]></description>
      <pubDate>Mon, 23 Aug 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/46200</guid>
    </item>
    <item>
      <title>FIXED HYDROFOIL CONTROL SURFACE</title>
      <link>https://trid.trb.org/View/30489</link>
      <description><![CDATA[The patent application relates to a fixed hydrofoil control surface for use as a rudder or pitch control fin attached to a vehicle, and having an elliptical hydrofoil shaped body with a pair of jet discharge slots formed parallel and along the trailing edge.  Liquid, forced out of one or the other slots, deflects the main flow from over the hydrofoil by the Coanda effect to one or the other side to create a positive or negative control force without the need of deflecting the control surface.]]></description>
      <pubDate>Wed, 21 Jan 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/30489</guid>
    </item>
    <item>
      <title>COMPREHENSIVE AUTOMATIC CONTROL SYSTEM FOR SOVIET HYDROFOIL CRAFT TAIFUN</title>
      <link>https://trid.trb.org/View/34961</link>
      <description><![CDATA[Taifun, the 66 tonne displacement Soviet hydrofoil craft with fully submerged foils, features a comprehensive automatic system for propulsion control.  Topping 45 knots in a force 3 sea and 40-41 knots in a force 4 sea, the hydrofoil will cruise in either calm water or force 4 wave conditions at 38 knots, giving a high level of passenger comfort.  The entire range of automatic control functions (data assembly and evaluation, including control decisions) is accomplished in accordance with preselected programmes. Crew functions are process supervisions, process data analysis and selection of operating modes for automatic equipment.  Control fuctions are illustrated.]]></description>
      <pubDate>Wed, 05 Nov 1975 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/34961</guid>
    </item>
    <item>
      <title>HYDROFOIL DEVELOPMENT--ISSUES AND ANSWERS</title>
      <link>https://trid.trb.org/View/16040</link>
      <description><![CDATA[The U.S. Navy has been actively engaged in the development of hydrofoil ships and craft since the late 1940's.  During this period, a number of controversial design issues have been addressed by analyses, model experiments, subsystems tests, and full-scale trials of several experimental prototypes.  This paper examines some of the central technical issues in retrospect and sets forth conclusions derived from development efforts.  Some of the issues discussed include: surface-piercing vs. submerged foils; canard vs. conventional strut-foil configurations; retractable vs. fixed foilsystems; flap vs. incidence control; analog vs. digital autopilots; platforming vs. wave contouring; flat vs. banked turning; waterjet vs. propeller propulsion; and material selection.]]></description>
      <pubDate>Tue, 07 May 1974 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/16040</guid>
    </item>
    <item>
      <title>SIMULATION OF HYDROFOIL PERFORMANCE IN CALM WATER</title>
      <link>https://trid.trb.org/View/15964</link>
      <description><![CDATA[A digital computer simulation program using Digital Simulation Language is produced to study the performance of a hydrofoil in calm water. Various automatic control systems are studied with the model constrained to the pitch-heave-surge mode of operation. (Author)]]></description>
      <pubDate>Tue, 07 May 1974 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/15964</guid>
    </item>
    <item>
      <title>CONTROL FAILURE SIMULATIONS OF THE PHM HYDROFOIL CRAFT USING A 1/20-SCALE DYNAMIC MODEL WITH AUTOMATIC CONTROL</title>
      <link>https://trid.trb.org/View/13954</link>
      <description><![CDATA[A 1/20-scale model of the PHM hydrofoil craft was developed with automatic control. Heave, pitch and roll motions were controlled by means of flaps on the forward secondary foil and on the port and starboard aft main foils. Motions lateral to the tank were constrained in this phase of the test program. The control system logic also provided for simulations of control system failure wherein any one flap or any combination of flaps can be thrown hard against mechanical stops. Only one flap was failed in any one run in this study. The trajectories subsequent to simulated control system failure were recorded for this five-degree-of-freedom model. Failures which lead to broaching of the bow foil appear to be serious. Failures which lead to hull impact do not appear dangerous. The results are discussed in more detail in the report. Recommendations for further development and utilization of this automatically-controlled, model, hydrofoil-supported platform are discussed. A second test phase with six-degrees-of-freedom and with steering control has been initiated. (Author)]]></description>
      <pubDate>Tue, 12 Mar 1974 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/13954</guid>
    </item>
    <item>
      <title>OPTIMIZATION OF FORWARD FOIL LIFT CONTROL FOR AG(EH) HYDROFOIL CRAFT. VOLUME I: HYDRODYNAMICS</title>
      <link>https://trid.trb.org/View/9966</link>
      <description><![CDATA[The report presents the foil and craft characteristics required by the Grumman Specific Linear Optimal Control Program for hydrofoil craft (SLOCOP). The characteristics are presented in generalized form, compared with certain experimental measurements, and evaluated for the AG(EH). The prediction confidence level is deficient in three significant areas: hinge moment, particularly for flaps; unsteady loading, particularly for orbital motion; and flap cavitation boundaries.  SLOCOP trending studies are underway to establish the sensitivity of the autopilot design to the unsteady loading representation employed.  These studies are intended to identify those unsteady loading responses for which further experimental effort is required for confident autopilot design.  (Author)]]></description>
      <pubDate>Wed, 14 Nov 1973 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/9966</guid>
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