Showing papers on "Guidance system published in 1972"

In-Flight Alignment and Calibration of Inertial Measurement Units - Part I: General Formulation

Abstract: This is the first part of a two-part paper which summarizes work pursued by the author in 1966 [1]. The paper describes the application of minimum-variance estimation techniques for in-flight alignment and calibration of an inertial measurement unit (IMU) relative to another IMU and/or some other reference. The first part formulates the problem, and the second part [2] reports numerical results and analyses. The approach taken is to cast the problem into the framework of Kalman-Bucy estimation theory, where velocity and position differences between the two IMU's are used as observations and the IMU parameters of interest become part of the state vector. Instrument quantization and computer roundoff errors are considered as measurement noise, and environmental induced random accelerations are considered as state noise. Typical applications of the technique presented might include the alignment and calibration of IMU's on aircraft carriers, the initialization of rockets or rocket airplanes which are launched from the wing of a mother ship, the alignment and calibration of IMU's which are only used in the latter phases of rocket flight, and for the initialization/updating of SST guidance systems.

Proportional lead guidance

Abstract: A guidance system for a missile or other vehicle utilizing a gyro stabilized seeker which is arranged in such a manner with respect to the missile as not to be servo controlled, but rather to follow the missile air-frame by means of passive coupling between seeker and airframe, as the airframe is steered to turn in response to seeker error signals. As a result of this arrangement the missile velocity vector is steered to point toward fixed targets or to lead moving targets. A further result of this arrangement is that the servo loop used to point the seeker toward the target in the conventional arrangement is not required and accordingly my missile guidance arrangement can achieve greater accuracy with less complexity than in the prior art.

4-D guidance system design with application to STOL air traffic control

Abstract: A new guidance technique, referred to as 4-D guidance, is being developed to improve the operation of future STOL aircraft transportation systems. 4-D guidance refers to a technique of synthesizing a complex three-dimensional flight path from simple pilot inputs and flying the aircraft along the path according to an ATC specified time schedule. The two major elements of a 4-D guidance system are the trajectory synthesizer and the control law for flying the aircraft along the synthesized trajectory using the aircraft's autopilot and autothrottle. Inputs to the trajectory synthesizer are the three-dimensional coordinates of waypoints, the turning radius, the speed range, the acceleration limits and the arrival time at time control waypoints. First the three-dimensional trajectory is computed using circular arcs and straight lines. Then the airspeed profile, compensated for wind, is calculated to achieve the desired arrival times. The pilot is informed if the arrival times cannot be achieved. The synthesized trajectory is stored as a time sequence of reference states and controls which the aircraft is forced to track using a linear feedback law.

Missile post-multiple-target resolution guidance

Abstract: A feedback loop for use in the guidance system of a guided missile being wn against multiple targets. The feedback loop modifies a transient signal present in the system by introducing a time lag sufficient to cause the missile relative heading change command signal subsequent to target resolution to be equal to the change in the missile antenna-to-target pointing vector that occurs at resolution.

Design and flight experience with a digital fly-by-wire control system using Apollo guidance system hardware on an F-8 aircraft.

Abstract: This paper discusses the design and initial flight tests of the first digital fly-by-wire system to be flown in an aircraft. The system, which used components from the Apollo guidance system, was installed in an F-8 aircraft. A lunar module guidance computer is the central element in the three-axis, single-channel, multimode, digital, primary control system. An electrohydraulic triplex system providing unaugmented control of the F-8 aircraft is the only backup to the digital system. Emphasis is placed on the digital system in its role as a control augmentor, a logic processor, and a failure detector. A sampled-data design synthesis example is included to demonstrate the role of various analytical and simulation methods. The use of a digital system to implement conventional control laws was shown to be practical for flight. Logic functions coded as an integral part of the control laws were found to be advantageous. Verification of software required an extensive effort, but confidence in the software was achieved. Initial flight results showed highly successful system operation, although quantization of pilot's stick and trim were areas of minor concern from the piloting standpoint.

Electromagnetic suspension guidance system for a moving vehicle

Abstract: The invention concerns an electromagnetic system for the suspension guidance of a moving vehicle with superconducting magnets. According to the invention, a combination of an electrodynamic and an electromagnetic suspension guidance system is provided. The system has the advantage that contactless electromagnetic suspension of fast vehicles is possible, for which the support and track guidance forces can be generated in a self-stabilizing manner, with a large air gap and low losses.

Reliability history of the Apollo guidance computer

Abstract: The Apollo guidance computer was designed to provide the computation necessary for guidance, navigation and control of the command module and the lunar landing module of the Apollo spacecraft. The computer was designed using the technology of the early 1960's and the production was completed by 1969. During the development, production, and operational phase of the program, the computer has accumulated a very interesting history which is valuable for evaluating the technology, production methods, system integration, and the reliability of the hardware. The operational experience in the Apollo guidance systems includes 17 computers which flew missions and another 26 flight type computers which are still in various phases of prelaunch activity including storage, system checkout, prelaunch spacecraft checkout, etc. These computers were manufactured and maintained under very strict quality control procedures with requirements for reporting and analyzing all indications of failure. Probably no other computer or electronic equipment with equivalent complexity has been as well documented and monitored. Since it has demonstrated a unique reliability history, it is important to evaluate the techniques and methods which have contributed to the high reliability of this computer.

Performance Limits of a Radio-Inertial Lateral Control System for Automatic Landing

Abstract: Parameter optimization techniques are utilized to explore the performance limits of a set of simplified radioinertial lateral path guidance systems subject to stochastic gusts, radio measurement noise and a constraint on rms control surface activity. The hybrid systems are shown to have rms lateral path errors less than half those of the pure radio systems for equivalent effector activity. The systematic generation of optimized solutions is shown to be particularly valuable in providing a performance bound for a system, against which the performance of a realizable configuration may be measured:

4-d guidance of stol aircraft in the terminal area

Abstract: 4-D GUIDANCE OF STOL AIRCRAFT IN THE TERMINAL AREABy Thomas Pecsvaradi* and Heinz ErzbergerNASA-Ames Research CenterSUMMARYThe primary objective of advanced STOL aircraft is the improvement of thenation's air transportation system by the elimination of delays and congestionsassociated with today's air travel. A new guidance technique, referred to as4-D guidance, is being developed to achieve this objective. The 4-D guidancetechnique synthesizes complex three-dimensional flight paths from a minimumset of input data and flies the aircraft along the paths according to a pre-\ specified time schedule. The two major elements of a 4-D guidance system arei •the trajectory synthesizer and the control law. Inputs to the trajectory synthe-sizer are the three-dimensional coordinates of way points, the turning radii,

Improved guidance hardware study for the scout launch vehicle

Abstract: A market survey and evaluation of inertial guidance systems (inertial measurement units and digital computers) were made. Comparisons were made to determine the candidate systems for use in the Scout launch vehicle. Error analyses were made using typical Scout trajectories. A reaction control system was sized for the fourth stage. The guidance hardware to Scout vehicle interface was listed.

Microwave radiometric guidance system

Abstract: A missile guidance system utilizing a single microwave radiometric sensor for both terrain correlation and target homing. Terrain correlation is used to get the missile within the acquisition range of the homing system, and the homing system is used in the terminal phase of operation.

Performance Limits of an Aircraft Inertial-Based Stochastic Lateral Guidance System

Abstract: The performance limits that can be achieved for a specified level of control activity are explored for a class of incomplete state feedback inertial data based lateral control systems in a stochastic gust environment. The stochastic optimization problem is defined and direct minimization of the performance index, consisting of weighted elements of the system covariance matrix, is carried out using parameter optimization techniques. Optimal solutions are presented for an inertial measurement based reduced state feedback lateral control system for the Convair 880 transport aircraft. The solutions provide a lower bound on the rms path deviation due to wind gusts which can be achieved with a specified level of control activity and also provide valuable guidance in the choice of primary lateral effector between ailerons and differential spoiler. The performance characteristics of a conventional radio coupler design for the CV880 are presented for comparison purposes.

Station-keeping guidance

Abstract: The station-keeping guidance system is described, which is designed to automatically keep one orbiting vehicle within a prescribed zone fixed with respect to another orbiting vehicle. The active vehicle, i.e. the one performing the station-keeping maneuvers, is referred to as the shuttle. The other passive orbiting vehicle is denoted as the workshop. The passive vehicle is assumed to be in a low-eccentricity near-earth orbit. The primary navigation sensor considered is a gimballed tracking radar located on board the shuttle. It provides data on relative range and range rate between the two vehicles. Also measured are the shaft and trunnion axes gimbal angles. An inertial measurement unit (IMU) is provided on board the orbiter. The IMU is used at all times to provide an attitude reference for the vehicle. The IMU accelerometers are used periodically to monitor the velocity-correction burns applied to the shuttle during the station-keeping mode. The guidance system is capable of station-keeping the shuttle in any arbitrary position with respect to the workshop by periodically applying velocity-correction pulses to the shuttle.

General Purpose Six Degree of Freedom Terminal Homing Missile Simulation Program

Abstract: : The report contains a description of a general purpose, 6-degree of freedom terminal homing missile simulation. The program uses quaternions for the coordinate transformations and features the use of subroutines to enter seeker, autopilot, aerodynamic, and wind models.

Y.:mf:h Guidance Systems Implementation Report A Proposed Model Program for Use in, American Secondary Schools

Abstract: The Youth Guidance Systems' (YGS) major goal is the encouragement and facilitation of considered decision making by every student. YGS seeks to establish goals, programs, and evaluation procedures which ensure continued change and relevance. Four goals have been stated for YGS (two student-centered and two staff-centered) to: facilitate decision making; provide personal problem counseling; use school, home, and community resources; and maintain continuous evaluation. Strategies identified to realize these objectives fall in these categories: (1) planning, including administrative and policy level planning, curricular and operational level planning, and articulation level planning; (2) differential staffing, including the staff role of the teacher, the administrator, the guidance coordinator, the counselor, the counselor assistant, the support staff, and volunteer aides; (3) guidance services, consisting of the guidance curriculum (group guidance), group counseling, individual counseling, and home-school-community interaction; and (4) evaluation. Basic changes involved in adopting the YGS model tc the school are identified. (SC)