Showing papers on "Rudder published in 1988"

Compound helicopter with no tail rotor

Abstract: This helicopter invention uniquely has no anti-torque tail rotor. The tail propeller is used only for forward thrust during the airplane mode of flight and during the transition from vertical helicopter flight to forward airplane mode of flight, when the helicopter rotor may be feathered in a no-lift attitude. The anti-torque balancing forces during the hovering mode are developed by the differentially controlled aileron forces when the wings are aligned vertically with the vertically downward airflow from the helicopter rotor. There is also a vertically moveable horizontal airfoil on the tail cone, or tail boom, with controllable means which can provide anti-torque reaction forces during the helicopter hovering mode from the lifting rotor down flow air. An angular moveable tail fin assembly and rudder are provided to improve transition from VTOL hovering flight to horizontal airplane flight. Means are provided to electronically schedule transition from the VTOL to horizontal cruise flight sensed by the wing attitude which can control the angular attitude of the fin and rudder in a completely computerized automatic transition to and from VTOL and airplane flight mode.

Aircraft modal suppression system

Abstract: Accelerations due to excitation of the natural modes of an aircraft's body are suppressed by an active suppression system. Dedicated accelerometers are positioned in the aircraft at optimal locations for sensing modal induced lateral accelerations. The accelerometer produced signals are processed through control logic which, in response thereto, and in response to aircraft velocity and altitude related signals produces output control signals. The control signals effect rudder deployment creating forces to suppress the natural mode induced accelerations.

Aircraft rudder command system

Abstract: An aircraft rudder command system for allowing a pilot to directly input a sideslip command for yaw-axis control through use of the rudder pedals is disclosed. The aircraft rudder command system includes a pedal input device for receiving a pedal input signal indicative of pilot rudder pedal input, a signal-receiving device for receiving feedback signals indicative of the current state of aircraft operation, a command generator system responsive to the pedal input signal and at least one of the feedback signals for generating a sideslip angle command, command limiting means for generating a limited sideslip angle command, and a feedback control system for transmitting a sideslip control rudder command to a rudder actuation system. The rudder actuation system causes the rudder to move in such a manner so as to produce an actual aircraft sideslip angle which follows the limited sideslip angle command. The aircraft rudder command system may also include a sideslip estimator. The sideslip estimator includes a component for receiving an airmass sideslip signal, a sideslip rate estimator for generating a sideslip rate estimate signal, and a complementary filter for synthesizing a sideslip angle estimate signal from the airmass sideslip signal and the sideslip rate estimate signal. The rudder actuation system, in turn, causes the rudder to move in such a manner so as to cause the sideslip angle estimate signal to follow the limited sideslip angle command.

The pterygotid telson as a biological rudder

Abstract: Functional hypotheses for fossil organisms can be rigorously tested through the application of engineering principles and physical laws (paleobiomechanics). Alternative functional models for the telson (tail spine) of the large pterygotid eurypterids are examined in terms of the hydrodynamics of fish propulsion and of ship rudders. The telson probably served as a rudder for steering in the horizontal and vertical planes during swimming, rather than as a thrust producer. The aspect ratio of the telson may approach an ‘optimum’, for the production of rudder forces over a wide range of angles of attack. Pterygotids may have been highly agile, rather than rapidly swimming animals. Eurypterids, functional morphology, paleobiomechanics.

Full authority engine-out control augmentation subsystem

Abstract: A full authority engine-out control augmentation subsystem for use in a flight control system to assist a pilot and/or lateral-directional control subsystem in compensating for the yawing moment produced by the differential engine thrust that occurs when the power produced by an engine located on one side of a multi-engine aircraft is lost (or reduced) with respect to the other engines is disclosed. The engine-out control augmentation subsystem produces a compensating rudder command (27) based on straight-gain (21), lag filter (15) and washout filters (23 and (25) modifications of a differential engine thrust signal (11). The engine-out control augmentation subsystem will function with both conventional mechanical and electronic (fly-by-wire) flight control systems.

A combined rudder and propeller arrangement

Abstract: A combined rudder and propeller arrangement for propelling, steering and maneuvring ships and other water craft. The arrangement includes a rudder (1) which is rotatable relative to the ship about a vertical rotational axis. Built together with the rudder (1) is a propeller unit (2) which includes a propeller (6) which is mounted on a horizontal propeller shaft journalled for rotation in a propeller unit housing (9). The unit is also journalled for rotation relative to the ship about a vertical axis. The rotational axes of the rudder (1) and propeller unit (6) coincide, such as to enable the rudder and unit to be rotated relative to one another. The rudder (1) may be connected to a steering machine (11, 13, 14) for rotation of the rudder whereas the propeller unit (2) is selectively lockable to either the ship in a fixed position, or to the rudder for co-rotation therewith.

Steering device for small sized jet propulsion boat

Abstract: An improved steering arrangement for a jet propelled watercraft including a rudder carried by the forward portion of the hull and which is out of the water at high speeds and submerged at low speeds for assisting in low speed steering without adding to high speed drag. The rudder and the steering nozzle of the jet propulsion unit are steered simultaneously.

Hydrofoil - submarine vessel system

Abstract: A high speed vessel system comprises a surface-craft, a sub-craft, a pair of main foils, at least a pair of auxiliary foils, a narrow strut connecting the sub-craft with the surface-craft The main propeller and main rudder are located at the stern end of the sub-craft hull When the vessel system is cruising at a high speed, the surface-craft will be lifted above the water line mainly by the buoyant force of sub-craft hull The foils will control rolling and pitching of the vessel system The surface-craft and sub-craft will be connected by a separable ball joint (first embodiment) or a plurality of rotatable links (second embodiment) when the vessel system is in sea operation The sub-craft can be raised up to the water surface level to minimize the draught of the vessel system when the system is resting in a harbor The present vessel system is specifically designed for a sea going vessel of big size and large tonnage, which needs to cruise at high speed constantly

Designing an automatic control system for a submarine

Abstract: : The purpose of this thesis is to linearize given non-linear differential equations and design a complete automatic control system for the three dimensional motions of a submarine. Automatic control systems are designed using a steady state decoupling scheme for vertical and horizontal motion. Both designs are simulated using the Dynamic Simulation Language (DSL) for both linear and non-linear models and compared. Cross-coupling effect between horizontal and vertical motions due to the rudder deflections is also investigated. Theses. (FR)

Manoeuvring mathematical model for a twin-propeller twin-rudder ship

Abstract: The MMG model is a modular type hydrodynamic model of proven value in various aspects of manoeuvring. However, this model was originally constructed for a single-propeller/single-rudder ship. In this paper, the various parameters included in the mathematical model for manoeuvring motion were investigated experimentally for a twin-propeller/twin-rudder ship. It was found that in general the MMG model, which was originally constructed for a single-propeller/single-rudder ship can be applied to a twin-propeller/twin-rudder ship, with the exception of the mathematical expression for the propeller wake. The authors modified the mathematical model for the propeller wake so that the corrected model can describe the characteristics for the propeller wake of a twin-propeller/twin-rudder ship. The predicted manoeuvring performance of a twin-propeller/twin-rudder ship was then compared with the results of free-sailing model tests showing the validity of the proposed mathematical model.

Maneuverability of Frigates in Waves

Abstract: This paper describes the setup of a mathematical model for the prediction of the maneuverability of frigates by means of computer simulations. For the maneuverability in still water, a quasi-static math description is used, while dynamic effects are added for the description of the maneuverability in a seaway. In this latter description, the dynamic effects of the rudder action on the ship's roll behavior are also incorporated.

A Study on the Manoeuvring Mathematical Model for a Twin-Propeller Twin-Rudder Ship

Abstract: The so-called M.M.G. mathematical model, a modular type of hydrodynamic model, has proven useful in studying various aspects of ship maneuvering motion. The model was originally developed for a single-propeller, single-rudder ship. Relatively little is known about the maneuvering performance of multipropeller, multirudder ships, though many are in use. The purpose of this paper is to contribute knowledge in this area by clarifying the maneuvering performance of one vessel of this type, the twin-propeller, twin- rudder ship. It is shown that the M.M.G. model can be applied for this type of ship as well, except for the mathematical expression of the propeller wake. This mathematical model of the wake is then modified to well describe the wake. Finally, the predicted maneuvering performance of the twin-propeller, twin-rudder ship is compared with the results of free-sailing model tests to examine the validity of the newly-proposed mathematical model.

Stern mounting structure for rudder, screw propeller, and shafting suitable for ships of any kind and use

Abstract: Stern mounting structure for rudder, screw propeller ,and shafting, suitable for ships of any kind and use arranged abaft the screw propeller that substantially comprises an integral to the hull, foil shaped post which sustains the rudderstock and an integral to the post boss which sustains the rudder heel and houses the last shafting bearing . Where a controllable pitch propeller (CPP ) is used, the post houses the most of the pitch control hydraulic de­vices in order to provide an apparatus wherein there are no rotating members under hydraulic pressure .

Rudder, in particular balance profile rudder for watercraft

Abstract: The rudder for watercraft consists of a rudder blade (30) with a fin (135) linked to it and a propeller (220) allocated to the rudder and arranged on a drivable propeller shaft (210), the rudder post (40) for the rudder blade (30) being mounted in a central inner longitudinal bore (25) of the rudder-trunk bearing (20), designed as a cantilever beam, by means of an inner bearing (50), while the rudder-trunk bearing (20) has on its outer wall surface an outer bearing (51) for mounting the rudder blade (30) on the rudder-trunk bearing (20) (Fig. 1).

Boat guidance stabilizer

Abstract: A stabilizer for controlling the steering of boats is made of an attachment plate, a friction controller and a spool; the attachment plate is attached to the tiller, rudder or an extension of either. The spool is mounted on the attachment plate and the friction controller is connected to the attachment plate via a spool post and is moved to increase or decrease pressure on the spool. The spool has, on its edge, a modified groove which can have a single knot hole, or can have one or more groove enlargements, discontinuities and/or can be zigzagged. A line is attached to the boat on one side of the stabilizer, wound around the spool for several turns and attached to the boat on the other side. The line is knotted at approximately the midpoint for use with a knot hole. Preferably the two sides of the line are then linked on the opposite side of the spool. This mechanism allows excessive pressure against the rudder to move an unattended tiller in emergencies. It also allows the person controlling the direction of the boat to move the tiller against the resistance of the friction when necessary to reposition the rudder.

Some experiments on maneuvering hydrodynamic forces in low speed conditions

Abstract: In order to obtain the basic data needed to predict harbor maneuvering motions, captive model tests were carried out earlier for a tanker-type ship over a wide range of drift angle and turning rate. This article deals with circular motion tests, tests using a propeller-rudder system without the ship body, and propeller open tests. Results clarify the characteristics of hydrodynamic forces acting on the ship hull, the interaction between propeller and rudder, and the open water characteristics of the propeller with a large drift angle. They demonstrate that the flow-straightening effect of hull and propeller and the increase in rudder inflow velocity due to the propeller working do not change remarkably with changes in the magnitude of maneuvering motions.

Aircraft autopilot with yaw control by rudder force

Abstract: An autopilot with long term yaw coordination capabilities which utilizes lateral acceleration to generate a rudder force command which is combined with the sensed rudder force to create an error signal which is combined with a rudder servo velocity signal and then integrated to create a virtual rudder position feedback signal for combination with the rudder position commands, generated from yaw rate information

Control system for a water-craft, in particular for a sailing yacht

Abstract: Control system for sailing yachts with an auxiliary engine, having a wheel, mounted on a control column, for controlling the rudder, and having an operating element, arranged coaxially with the wheel, for controlling the engine. The operating element is situated in front of the wheel and can be switched from an inactive to an active position in a force-closed and self-closed fashion; cf. Figure 2.

Sailing vessel hull with steering fins and ballast trimming vanes

Abstract: The problem with a sailing yacht is known. High superstructure, mast, sail, the wind pressure and thus the drift. In order to prevent the drift and capsizing of the boat, a heavily ballasted keel is attached to the hull according to the age-old and fully superseded custom. This obsolete type of construction makes the boat sluggish and inflexible. Four extendable and retractable steering fins replace keel and rudder much more effectively. They guide the hull as if on rails and make it manoeuvrable like a formula-one racing car. Additional ballast trimming vanes at the steering fins enable the entire ballast weight to be trimmed over the entire width of the vessel, and at the same time forward and aft. It is thus possible to sail the sailing yacht far closer to the wind. The electronically, hydraulically controlled ballast trimming vanes stabilise the boat in the longitudinal axis, keep contact with the water and put the boat into an optimum planing phase.

Rudder, particularly balanced profile rudder for water craft

Abstract: The rudder for water craft comprises a rudder blade 30 with a fin articulated thereto and a propeller associated with the rudder and located on a drivable propeller shaft. The rudder stock 40 for the rudder blade 30 is mounted in a central inner longitudinal bore of the rudder port bearing 20 constructed as a cantilever beam by means of an inner bearing 50, the rudder port bearing 20 having an outer bearing 51 on its outer wall surface for mounting the rudder blade 30 on the rudder port bearing 20.

Automatic control device for weight trim of underwater boat

Abstract: PURPOSE:To enable weight and trim to be automatically adjusted, by calculating the weight and the trim in accordance with an output of each sensor, which detects a rudder angle, speed, depth, pitch angle and a fluid amount of each tank, and controlling water to be injected into and discharged from each tank on the basis of the calculated result. CONSTITUTION:A sumarine provides a rudder angle sensor 1, speed sensor 2 (for water), depth sensor 3, pitch angle sensor 4, front and rear parts each trim fluid amount sensors 5, 6 and an auxiliary trim fluid amount sensor 7. On the basis of detection data from these sensors and the kinetic characteristic from a kinetic characteristic memory 8, weight and trim of the submarine is calculated in a calculating circuit 9 through the optimum estimation by a Kalman filter, and the here obtained weight and trim and preset weight and trim from a weight and trim setter 10 calculate an inject and discharge transfer amount of water of each tank by a calculating circuit 11. And in accordance with the calculated result, front and rear part each trim tank valve 13, 14, auxiliary tank valve 15, injection and discharge water valve 16, etc. are controlled by a tank fluid amount control means 12.

Rudder with turbulent flow mechanism

Abstract: The utility model belongs to the rudder structures for marine and is a rudder with a rectifying component. Compared with the rudder with the rectifying component disclosed in Japanese Zhao 59-8597, the utility model enables the rectifying component to always keep 0 DEG rudder angle in perfect state and makes full use of the energy of slip stream, and the boosting effect is good. The utility model is characterized in that the rudder is positioned from front to back as follows: the 1/4-3/4 range is a fin [1] fixed with respect to the marine body; the interval between the fin [1] and the rudder [2] to permit the rudder to rotate flexibly makes the rudder [2] rotate, and the fin [1] is fixedly provided with the rectifying component which can be made into a plurality of shapes.

Catamaran of reverse hull

Abstract: The utility model discloses a catamaran of reverse hulls, which is a ship with large area, good stability, and strong maneuverability. Each sheet body of the catamaran is changed into a plate sheet body whose horizontal surface is left-right asymmetrical. The external side of the catamaran hull is flat. A side thruster is used to substitute the rudder by adopting a counter-rotating propeller which is arranged in the middle of the catamaran. The utility model has the advantages of high propulsive efficiency, small wave making during sailing, and good maneuverability. Besides, utility model can pirouette, move in parallel to the left and right no matter the host machine is stopped or not, and can moor downstream at a quay when sailing along rivers.

Propulsion auxiliary device.

Abstract: The auxiliary propeller (5) is supported by the rudder horn (4) behind and independently of the main propeller (2), and the same (5) is attached to the rudder horn (4) from the direction of the forward side (B), that is to say in the direction of the backward water stream (F) produced by the main propeller (2), the main propeller shaft does not sustain any weight of the auxiliary propeller (5), the oil line (12) is not formed inside the main propeller (2), and even if the auxiliary propeller (5) sticks to the rudder horn (4), it will not affect the main propeller (2) and the main propulsion system. overall.

Steering apparatus for fully submarged hydrofoil

Abstract: PURPOSE:To accomplish easy driving and comfortable cruising by providing an inclinometer which detects the amount of heel of a hull and a steering wheel angle detector and making steering control according to the amount of the angle of the steering wheel CONSTITUTION:Each of the signal of steering wheel angle theta detected by a steering wheel angle detector 12 and the signal of rake angle theta detected by an inclinometer 13 is input to a controller 14 and processed, then the controller 14 generates signals which drive servomotors 8 and 9 and outputs the right and left steering amounts to steer a front rudder 6 and a rear rudder 7 The rudder 6 and 7 are steered in the same direction according to the amount of heed from the neutral position detected by the inclinometer 13 when the angle thetafrom the neutral position detected by the detector 12 is zero They are steered in the same direction according to the amount of the angle theta when the angle thetais not zero and also, by the results of it, they are steered severally in the deferent directions according to the amount of heel detected by the inclinometer 13

Glide board with rudder

Abstract: Board with rudder comprising on its lower face at least one rudder mounted for swivelling in the body of the board and actuatable by a means accessible on the upper face of the board, disposed substantially in the central zone of the board and formed of two manual members separated by a profiled portion formed so as to allow the user to lie on the board with his chest along said profiled portion, said board being provided in its rear half-portion, on its upper face, with two parallel elongate housings formed in the mass of the board for receiving the leg portions of the user below his knees, when kneeling on the board.

Rudder for ship

Abstract: PURPOSE:To reduce the cost and facilitate the inspection, maintenance, and check, by constituting a rudder for ship with two rudder plates having almost the same shape in parallel behind a propeller, a connecting member of these two rudder plates, and a rudder shaft fixed at the center between the rudder plates of this connecting member and rotating two rudder plates. CONSTITUTION:Two rudder plates 12-1, 12-2 provided in parallel at the preset distance behind a propeller 11 receive the back wash of the propeller 11, efficiently generate the lift, serve as a nozzle, and apply a large rudder force to a hull. Connecting members 13, 14 connect the rudder plates 12-1, 12-2 and fix them to a rudder shaft 15 and convey the torque of the rudder shaft 15 to two rudder plates 12-1, 12-2 to rotate them. The simple structure constituted of two rudder plates 12-1, 12-2, the connecting members 13, 14, and the rudder shaft 15 facilitates its production, and the inspection, maintenance, and chick can be performed simply.

Control Surface Selection Based on Advanced Mode Performance

Abstract: In the past decade there have been two major aspects which have influenced the design of aircraft from the dynamic stability point of view: improvement in avionics in terms of reliability and computational speed and the introduction of the concept of system integration and task oriented flight control system. these aspects have led to the development of demonstrators which have flown and whose performances have been extensively evaluated in order to identify potential design solutions to be implemented in actual flight (AFT1-F16, X-29, Mirage 2000, EAP). Attaining advanced modes of motion requires not only the development of more complex flight controllers, but it also influences the preliminary design phase in terms of the aircraft center of gravity location, and in the choice of the control combination most appropriate for the optimum aircraft response. The present paper considers the problem of control surface selection to implement a fuselage-aiming mode. Canard-flap and elevatorflap pairs will be considered in the longitudinal plane, whereas rudder plus vertical fin or antisymmetric brakes are evaluated in the lateral plane. The figure of merit is based solely on closed loop dynamics behavior and flight control system requirements.

Ball leading screw driving manual oil pressure steering engine

Abstract: The utility model discloses a manual oil pressure steering engine taking a ball leading screw as a main drive structure, and is suitable for steering light-tonnage vessels such as fishing boats, cargo ships, oil tankers, passenger ships, barges, etc. One end of the ball leading screw is directly provided with a hand wheel, and the other end extends in the hollow stem of a piston. The ball leading screw rotates in clockwise or in counter clockwise along with the hand wheel when the hand wheel rotates. A screw nut with a ball moves forwards and backwards to drive the piston to move reciprocally. Accordingly, the pressure oil is pressed into a rudder pushing oil cylinder through pipelines to make the rudder arm swing for a certain angle leftwards or rightwards rounding a rudder axle in order to obtain the steering purpose.

Hung rudder with radial rudder plate

Abstract: PURPOSE:To promote the improvement of propulsive performance, by providing plural rudder plates to be radially arranged to the bottom laterally diagonally from a part on the axial line of a propeller and setting an attack angle of said rudder plate such that a lift for a propeller rotating race generates its longitudinal directional component in the advance direction. CONSTITUTION:A rudder horn 5a in the bottom part of a ship body 1 supports a rudder 4, and its upper part rudder plate 4a connects to its bottom end bottom part rudder plates 4b, 4c radially opened to the bottom laterally diagonally from an extension line of the axial center of a propeller 2. These bottom part rudder plates 4b, 4c, forming their section in a streamline shape, receive a rotating race Vp of the propeller 2, when the ship body 1 advances, generating a lift L and a drag D but setting an attack angle alpha, so that their resultant force F generates its component S in the longitudinal direction of the ship body 1 being directed to the advance direction, while aspect ratio to provide a sufficiently large value. In this way, the rudder, while it ensures sufficient steering force, enables resistance of the rudder to be reduced while generates thrust force by the rudder, and the ship body enables its propulsive performance to be improved.