Showing papers on "Missile published in 1976"

The closed-form solution of true proportional navigation

Abstract: The closed-form solution of the equations of motion of an ideal missile pursuing a nonmaneuvering target according to the true propotional navigation law is obtained. An analysis of the solution is performed, and the conditions necessary for the missile to reach the target are determined.

Defending a Moving Target Against Missile or Torpedo Attack

Abstract: Problems involving kinematics of a counterweapon intercepting an attacking missile are well known. However, when the attacker's target, the counterweapon's launch platform, is moving, the problem generally becomes amenable only to trajectory simulation. Such may be the case in defense against torpedo attack against a ship and other situations involving the use of antimissile missiles. This paper derives the kinematic relations among the three bodies (missile, target, and counterweapon) in closed form under the asymptotic approximation of constant-bearing trajectories (collision courses). It is shown that the defending target, even if moving, can still determine the optimum course for its counterweapon when range and speed of the attacking vehicle are unknown. A simple relation is derived for the ratio between the attacker-target range (and time to impact) at counterweapon launch and the range at interception of the attacker by the counterweapon. Normalized curves are presented for some representative cases of defense by a counterweapon of known speed against a torpedo or missile attack on a moving target. The equations are shown to reduce to the familiar form for a stationary target.

Experimental Roll-Damping, Magnus, and Static-Stability Characteristics of Two Slender Missile Configurations at High Angles of Attack (0 to 90 deg) and Mach Numbers 0.2 through 2.5

Abstract: : An experimental investigation was conducted to verify that the recently developed high-alpha missile roll-damping test mechanism could be used to obtain the roll-damping characteristics of slender missile configurations and to obtain roll-damping, Magnus, static-stability, and axial-force characteristics of a typical missile configuration. The verification tests were conducted with the Basic Finner Model at M = 0.22 and 2.50. Additional test results were obtained with a Modified Basic Finner Model for Mach number 0.6 through 2.5.

Strategic Vulnerability: The Balance Between Prudence and Paranoia

Abstract: IXmong its many consequences, the basic agreement on strategic arms limitations announced at the Vladivostok summit in November 1974 seems destined to energize a long simmering debate over the vulnerability of the land-based missile component of the United States strategic forces. The decidedly permissive limit on multiple-warhead missiles, tentatively set at 1320, means that each side will be able to allocate a relatively large number of separately directed warheads to each of the opponents' landbased installations. Since controls are imposed 'on current missile installations and since the Soviets have built larger silos for missiles with greater payload, they will be able to build a force with six or more warheads targeted on each silo in the American force-if they match American warhead technology and if they strain the limits of the agreement. Trends in accuracy and yield-to-weight efficiency are such that a force of this size according to standard, widely accepted calculations would appear to give the Soviets a decisive first strike advantage against one component of the United States' strategic forces-the one which contains most of our capacity for flexible nuclear retaliation. It has been authoritatively asserted and seems to be widely believed that such an apparent advantage would translate into diffuse but significant political advantages across the many international issues in which the two countries are involved. There have been many attempts to deal with this issue of ICBM vulnerability by summary arguments designed to remove the problem a priori. Many have pointed out, for example, that strategic missile submarines remain invulnerable to a swiftly executed preemptive attack, and they have argued that devastating retaliation. from the United States submarines (or submarines and bombers in combination) would be so certain as to render a first strike completely irrational and therefore as unlikely as any deterrent policy can make it. Others have noted that various detection systems allow the United States to observe Soviet missile launchings and to plot their trajectories, and they have argued that this capa-

Missile Stability Using Finite Elements—an Unconstrained Variational Approach

Abstract: The stability behavior of a flexible missile idealized as a free-free beam is studied using the finite-element technique. The structure is assumed to be under a constant thrust which, in turn, is subjected to a directional control device. A concentrated mass is included to model a piece of heavy machinery. The solution formulation - finite element in conjunction with unconstrained variational principles -is shown here to be general, simple to use, and effective to overcome the difficulties arising from nonconservative forces, concentrated mass, and feedback control features. As a basis of this approach, an unconstrained variational statement and the associated adjoint problems are introduced. Numerical results from this study reveal that 1) for a free-free beam under a constant thrust, there exists a nonzero mode which seems to have escaped previous investigators; 2) since this newly realized mode is the lowest nonzero mode and is divergent in nature, a missile structure is unstable without feedback control; and 3) depending on the amount and location of a concentrated mass, it can improve the stability behavior of a missile.

Missile system using laser illuminator

Abstract: A system for intercepting a target with a missile having semi-active homing guidance. The target is discretely illuminated by a laser beam and the missile homes on the reflected illumination from the target.

Missile guidance system utilizing polarization

Abstract: A missile guidance system in which a projectile or missile is fired toward predetermined target with the missile being tracked on its flight toward the target by radar, processing the radar information in a computer apparatus and finally computing a new trajectory from the missile to the target and transmitting correction signals to a correction device on the missile including thrusters on the missile to cause the trajectory of the missile to be changed to the newly computed trajectory for the missile This system corrects the trajectory of the missile while in flight by recomputing a trajectory from the missile to the predetermined target and making appropriate corrections each time Thisenables the missile to only contain radar reflecting means, and correction detection and control means on the missile rather than having gyro and other type devices on board the missile which take up a considerable amount of space and weight

Missile launcher for aircraft

Abstract: A mechanism rapidly and repetitively launches missiles from inside an aircraft during flight. One or more missiles are carried and launched through a tube protruding through the front of the aircraft thus obviating the necessity for bomb bay or other sizeable, open doors. The aircraft interior may be used as a large accumulator so that pressurized internal air is utilized as the propellant when admitted to a breech. Thus, a "cold" launch is achieved negating the possibility of a "hang fire". Multiple missiles can be carried in revolving chambers which are capable of rapid rotation into firing position. The advantages of the system include the ability to launch at high aircraft altitudes and speeds with the missile moving toward the target.

System for transmitting light signals between a missile and a missile control station

Abstract: A system for transmitting light signals between a missile and a missile control launching site is provided by utilizing a laser beam light signal transmission path. The system comprises a laser emitter having a relatively broad transmission beam for producing a transmission path for the modulated light signals during the flight of the missile. The system obviates the need for light transmission lines or other physical connection between the missile and the control station and provides for continuously aiming the laser beam on the missile by means of a follow-up device responsive to a portion of the beam reflected from the missile. At least one crown of triple mirror reflectors is distributed about the axis of the missile to enable the missile to reflect the laser beam impinging thereon independently of the flight position of the missile. The laser beam is modulated to transmit control light signals from the control station and information light signals from the missile.

Guidance system for missiles

Abstract: A missile guidance system is provided in which a sensor is pivotally mounted on the missile in a gimbal system having two degrees of freedom. The sensor is controlled during flight in such a manner that the axis of the sensor is aligned in a direction determined by the acceleration of the missile, and the sensor locates the target and determines the angle between the direction of the sensor axis and the direction of the target. Guidance information is derived from this angle for directing the missile toward the target. Compensation for gravity may be provided by means of a spring suitably arranged in the gimbal system. The sensor system may be either active or passive and may be responsive to any desired type of signal from the target.

Dual mode guidance system

Abstract: A dual mode missile guidance system employing a passive anti-radiation ser for midcourse guidance and an alternate sensor for terminal guidance. A broadband, body mounted conformal antenna comprises the midcourse sensor, and the alternate sensor is mounted on a stabilized platform within the missile radome. Detected video guidance signals from the midcourse sensor are video processed and utilized to adjust the system phase shifters for null tracking as well as for driving the stabilized platform to keep the alternate sensor directed at the target. Upon the occurrence of a predetermined condition, a handover switch connects the detected video guidance signals provided by the alternate guidance sensor processor for video processing and for control of the stabilized platform. Auto pilot signals are derived from the rate gyros mounted on the stabilized platform.

Optical attitude reference

Abstract: The optical attitude reference system provides missile attitude reference ing an optical beam in lieu of conventional gyroscopes. In the missile control systems autopilot, the system uses the properties of polarized light to determine missile roll angle relative to the beam transmitter reference axes at the launch site.

Radiant energy power source for jet aircraft and missiles

Abstract: A radiant-energy-sensing power system applicable to aircraft having jet-type engines, vehicles having gas turbine engines, and missiles, comprising photovoltaic type cells mounted in the proximity of the combustion chamber of a jet engine and the aft end of a missile whereby the photovoltaic solar cells receive a portion of the radiant energy from the burning of the jet or missile fuel and convert same to electrical energy for use in the aircraft, missile, or vehicle.

Missile guidance system

Abstract: The invention relates to missile-guidance systems of the semi-active homing type using the Doppler effect, designed for air-to-air, ground-to-air or ship-to-air installations. On the radar installation, a first illuminator comprising a directional antenna illuminates a target with a wave of first frequency F 1 . The wave reflected by the target is picked up by an antenna situated at the front of the missile. A second illuminator comprising a wide-beam antenna illuminates an antenna situated at the rear of the missile with a continuous wave of second frequency F 2 coherent with the wave of frequency F 1 . The local oscillator in the receiver of the missile is phase-controlled in dependence upon the continuous wave of frequency F 2 .

Offset beacon homing

Abstract: A system for enabling homing by a missile onto a target which is marked by beacon at some other location. A radio frequency beacon is located remotely from the intended target. Target coordinates relative to the beacon are obtained and relayed by conventional means to the launch site and are stored in missile memory. During flight the missile seeker acquires, interrogates and tracks the beacon. The missile borne equipment generates guidance signals which alter the trajectory to the target location.

Motion-induced stimuli initiation system

Abstract: A motion-induced stimuli initiation system for actuating various missile otechnic devices based upon attainment of specified values of acceleration, velocity and distance after launch. Data from accelerometers are integrated to obtain velocity, the velocity data are integrated to obtain distance. Comparison of acceleration, velocity and distance with predetermined values by appropriate logic circuitry provides the signals to initiate the pyrotechnic devices.

Fiber optic missile guidance and control

Abstract: A fiber optical transmission system for guiding and controlling a missile.he fiber optic link can provide for up and down link transmission that can provide target and reference position information not available to present wire guided missile systems. Fiber optics have an almost unlimited information transfer rate and does not have the electrical interference problems of the wire systems.

Optimal and Suboptimal Guidance for a Short-Range Homing Missile

Abstract: Optimal and suboptimal guidance laws for short-range homing missiles are developed and compared to the commonly mechanized quidance law of proportional navigation. The optimal controller is derived as an optimal feedback regulator; the suboptimal controller is an approximation of the optimal regulator and consists of timevarying proportional navigation plus a time-varying gain term times a calculated target acceleration. Monte Carlo studies of the three controllers show that the optimal and suboptimal controllers are much superior to proportional navigation for the case of combined constant target acceleration, line-of-sight rate noise, and missile acceleration saturation.

Timed missile flight termination system

Abstract: A pressure activated, timed missile flight termination system for destroy a test missile after a predetermined period of flight to shorten its hazard space so that it can be used on firing ranges having a minimum amount of area. A delayed destruct sequence is initiated by pressure in the missile combustion chamber upon ignition of the missile. A pressure driven piston is compressed by the pressure created in the combustion chamber, causing it to strike a primer which initiates a delay fuse, a detonator, and a linear-shaped charge to destroy the missile.

Simplified high accuracy guidance system

Abstract: A simplified guidance system for air-to-air missiles where the pilot adjusts his helmet sight to compensate for missile errors and this information is fed to a computer which computes correction data from error information, aircraft position information and missile position information, correction data is then sent via a radio link to the missile control system which changes the flight path accordingly.

Aircraft Missile Avoidance

Abstract: The game of two cars defined by Rufus Isaacs is visualized here in terms of missile avoidance by an aircraft. With the system dynamics specified and confined to the horizontal plane, the distinctiveness between Isaacs' original problem and ours lies not only in the choice of parameters, but in the choice of assigned player rationale as well. In particular, we obtain three different capture zones. The capture zones are defined in terms of the barriers separating regions of capture from noncapture. We obtain a game barrier by assuming both the missile and the aircraft use optimal (qualitative game) control, a proportional navigation barrier by assuming the missile is using proportional navigation and the aircraft is using optimal evasive control, and a green barrier by assuming no control action by the aircraft with the missile using optimal pursuing control. The first two barriers allow for a qualitative comparison of proportional navigation guidance-to-guidance based on game theory. The green barrier give...

Umbilical cord breaker

Abstract: An improved device for breaking the connection between an electric control system and a missile by separating a control cable or umbilical cord joining the missile to its launcher housing during launch. A plurality of continuous, flexible conductors are passed through openings in a non-conductive insert in the surface of the missile. Because the conductors are secured to both the missile and the housing on opposite sides of the insert, they are tensioned against and bent over the outer edge of the opening during launch and broken due to the concentration of tensile and bending stress at the point of contact.

Tornado-Borne Missile Speeds

Abstract: To ensure the safety of nuclear power plants in the event of a tornado strike it is required that, in addition to the direct action of the wind and of the moving pressure field, the designer consider the impact of tornado-borne missiles, i.e., of objects moving under the action of aerodynamic forces induced by the tornado wind. It is, therefore, necessary that estimates be made of the speeds attained by potential missiles under such tornado wind conditions as are specified for the design of nuclear power plants. To calculate such speeds a rational model for the tornado-borne missile was proposed, based on the assumption that the missile tumbles during its flight, and a computer program was developed, based on this model. Missile trajectories and speeds were calculated corresponding to various assumptions regarding the initial conditions and the tornado wind field. The sensitivity of the results to changes in these assumptions was examined.

Night guidance of self-propelled missiles

Abstract: A method for masking on the display device associated with a thermal telescope for the night guidance of self-propelled missiles carrying an infrared source, the image of a source of relatively intense stray radiations, wherein, on the one hand, the radiations transmitted in the field of vision of the thermal telescope are simultaneously detected in two different spectral bands, of which the one, called the useful band, corresponds to the maximum radiations from the target and the surrounding landscape, and the other one, called stray band, corresponds to the maximum radiations from the intense infrared sources carried or not by the missile, and on the other hand the signal detected in the first band is corrected by the signal detected in the second band in a manner to leave out the stray portions of the useful signal.

Method and system for gravity compensation of guided missiles or projectiles

Abstract: A control system for a guided missile or projectile in which signals to compensate the steering commands of the guided missile or projectile for the effects of gravity are dynamically produced and stored while the missile or projectile is in flight. The system includes a gyroscope mounted in the missile or projectile for establishing an attitude reference axis independent of the attitude of the missile or projectile. Gravity compensation signals are generated in response to sensed angular differences between the attitude at the missile or projectile and the reference axis, and the generated gravity compensation signals are stored. The missile or projectile steering commands are then compensated for gravity effects by use of the stored gravity compensation signals during the guidance mode of operation.