Showing papers on "Guidance system published in 1988"

Miss distance analysis for command guided missiles

Abstract: A concise theoretical technique is presented for estimating the minimum miss distance capability of command guided missile systems using synthetic proportional navigation. The effect of the parameter values on the system capability is shown to be a function of range-to-intercept; the technique enables the system designer and analyst to quantify system performance and to develop a systematic understanding of the performance limitations of command guidance systems at each intercept range. New analytical equations based upon adjoint theory are developed for statistical miss distance caused by target maneuver, range-dependent, servo, glint and atmosphere noises for command guided systems. An optimal total system time constant is derived which yields the minimum statistical miss distance. Realistic constraints on the minimum achievable system time constant are considered. The equations derived for the optimal total system time constant are valuable to the system designer for minimizing miss distance over the ranges of system parameters and limitations, and intercept conditions.

Individual driver route guidance systems and their implications for traffic control

Abstract: While the basic concept of guiding individual drivers en route to their destination using on-board computers was introduced more than two decades ago, a practical implementation of this concept has only become possible as part of the current microcomputer–communications revolution. This paper assesses the potential role of these on-board route guidance systems as a means of better assisting drivers to make routing decisions and to improve the quality of the data available to the central traffic control system. The assessment indicates that the potential capabilities of these systems are controlled by the type of communications between the on-board units and the central control system, the level of on-board intelligence that is provided, and the integration of these activities within the traffic control model. Key words: traffic control, individual route guidance, driver information systems.

The Sum-and-Lattice-Points Method Based on an Evidential-Reasoning System Applied to the Real-Time Vehicle Guidance Problem

Abstract: Publisher Summary This chapter discusses the sum-and-lattice-points method based on an evidential-reasoning system applied to the real-time vehicle guidance problem. It presents a methodology for research and development of the inferencing and knowledge representation aspects of an expert system approach for performing reasoning under uncertainty in support of a real time vehicle guidance and navigation system. Such a system can be of major benefit for nonterrain following low altitude flight systems operating in foreign hostile environments. The chapter describes the basic research, development, and conceptual design of a prototype based on numerical algorithms and an evidential-reasoning expert system for effective real-time flight guidance and navigation. The primary function of the expert system is, at a minimum, to provide the pilot with guidance or to perform autonomous navigation and response. This response is based on the perceived situation in conjunction with the mission and basic operational guidelines. The information combination and usage of artificial intelligence techniques for real-time flight guidance system yield the real-time displays, recommendations to the pilot, and the automated computer commands to the flight vehicle.

Development of navigation guidance and control technology for Indian launch vehicles

Abstract: The orbital injection accuracy of any payload depends on the calibre of the inertial guidance system used on board the launch vehicle. This paper outlines the mission definition and the rationale for the selection of a proper guidance system to meet final mission objectives. The functions and the architecture of the navigation, guidance and control are discussed. The developmental aspects of the sophisticated inertial sensors, inertial systems, associated complex electronics, on-board computers, control actuators and systems are reported. The complexity of the on-board control and guidance software and the test and evaluation procedures used for their validation are included. The general scheme of the inertial guidance systems and the critical role played by them in the realization of Indian satellite launch vehicles SLV-3, ASLV and PSLV are presented in brief.

An automatic guidance, navigation and collision avoidance system for ships at sea

Abstract: The paper concerns work on the development of a voyage management system which takes navigational data from such navigation aids as are fitted on the vessel, collision avoidance data from the ship's radars, and meteorological data from shore stations via a satellite link. After appropriate filtering, this data is used as input to a multivariable optimal controller which will maintain the vessel on the correct track between ports, with due consideration to safety, efficiency and economy of operation. The navigation and guidance system has been tested afloat, whilst simulation studies have demonstrated that the automatic collision avoidance and weather routeing systems can be incorporated in to the overall voyage management system. The next step is to develop a complete prototype system and undertake extensive trials in coastal and oceanic waters.

Route following and driving performance with in-car route guidance systems

Abstract: In-car electronic route guidance systems are presently in development and are likely to be introduced in the nineties. It is often assumed that auditory presentation of navigation information is preferable because of the existing visual load of the driving task. The aim of the present study was to (a) create a theoretical frame of reference; and, (b) to compare visual and auditory information presentation with respect to their effect on driving behaviour and mental load in real driving conditions. Moreover, both electronic systems were compared with the conventional way of navigation, i.e. With a commercially available map. From theoretical considerations it was suggested that auditory information is better suited to drivers who are inexperienced with the use of in-car route guidance. With experience, however, drivers might be able to integrate intake of visual information with driving, thus increasing their performance. The empirical study showed slightly better driving performance for auditory information under average driving conditions. It was also demonstrated that electronic guidance systems are especially useful if drivers are unused to navigation, on complex routes and with high traffic density. Because of confusion between the speed, modality and format of information, further research should be carried out on these variables under highly demanding conditions with a large variety of subjects.(a)

Automatic Control Of Agricultural Machines

Abstract: Studies on productivity improvement in agriculture by automation of agricultural machines have been progressing rapidly in recent years. Some of them are already put into actual use, which are reported in this paper. They deal with automatic control of the working equipment of agricultural machines. The productivity of agricultural machines is expected to be improved tremendously when the technology of automatic vehicle guidance is put into practical use. As automatic guidance technology, an autonomous guidance system using simple input signals, an autonomous guidance system using input signals required for control extracted from multiple video information signals, and an externally assisted guidance system using a fixed laser oscillation source have been studied with respect to their properties. As a result, it has been found that selective use of these three systems according to the job requirements of agricultural machines will attain the above purpose.

Electronic route guidance in congested networks

Abstract: Described here is Q-Route, a prototype driver information system that can provide improved route guidance through congested networks using three compatible subsystems: pretrip planners; changeable message signs; and on-board route guidance system. The article illustrates how these 3 subsystems can be seen conceptually and physically as variations of the same basic driver information system. It describes how the routing data can be generated, and indicates how Q-Route's pre-trip planner, changeable message sign driver, and on-board unit prototypes were developed. Their use is illustrated using a sample application in the Kingston, Ontario, Canada network. The article indicates how the system should be organized to be more consistent and comprehensive.

A design study of onboard navigation and guidance during aerocapture at Mars

Abstract: The navigation and guidance of a high lift-to-drag ratio sample return vehicle during aerocapture at Mars are investigated. Emphasis is placed on integrated systems design, with guidance algorithm synthesis and analysis based on vehicle state and atmospheric density uncertainty estimates provided by the navigation system. The latter utilizes a Kalman filter for state vector estimation, with useful update information obtained through radar altimeter measurements and density altitude measurements based on IMU-measured drag acceleration. A three-phase guidance algorithm, featuring constant bank numeric predictor/corrector atmospheric capture and exit phases and an extended constant altitude cruise phase, is developed to provide controlled capture and depletion of orbital energy, orbital plane control, and exit apoapsis control. Integrated navigation and guidance systems performance are analyzed using a four degree-of-freedom computer simulation. The simulation environment includes an atmospheric density model with spatially correlated perturbations to provide realistic variations over the vehicle trajectory. Navigation filter initial conditions for the analysis are based on planetary approach optical navigation results. Results from a selection of test cases are presented to give insight into systems performance.

Lateral Guidance System Requirements Definition

Abstract: Institute of Transportation Studies University of CaIifornia, Berkeley PROGRAM ON ADVANCED TECHNOLOGY FOR THE HIGHWAY Lateral Guidance Systems Requirements Definition Robert E. Parsons Wei-Bin Zhang PATH Research Report UCB-ITSPRR-88-l October 1988

Closed Loop Navigation and Guidance for Gravity Probe B Orbit Insertion

Abstract: This paper addresses the problem of guiding the Gravity Probe B (GP-B) spacecraft from its location after initial insertion to a very precise low earth orbit. Specifically, the satellite orbit is required to be circular to within 0.001 eccentricity, polar to within 0.001 deg inclination, and aligned with the direction of the star Rigel to within 0.001 deg. Navigation data supplied by an on-board GPS receiver is used as feedback to a control algorithm designed to minimize the time to achieve the desired orbit. Translational control is provided by the proportional helium thrusters, which are used for drag-free and attitude control during the remainder of the science mission. Simulations of the guidance system are presented which give an indication of performance characteristics for several types of orbit injection errors. This research is the first reported effort to use GPS as a sensor for a closed loop space guidance system.

Analysis of coloured filter controllers for bank-to-turn CLOS guidance

Abstract: Coloured-noise Kalman filtering theory is used to deal with glint noise on the position error measurements in a bank-to-turn CLOS guidance system. Frequency-domain analysis suggests thatthe coloured-filter controller could be replaced by a white-filter controller without any significant loss in performance. Simulation results confirm this conclusion

Integrated Guidance and Control for Combined Command/Homing Guidance

Abstract: This paper describes an integrated design approach for a tactical missile which derives guidance commands from both a strapdown terminal homing seeker and a fixed-based radar system To deal with initial errors between the fixed-based radar and missile reference systems, a separate navigation filter is designed which estimates any misalignments using the fixed-based radar measurement of the missile position and outputs of the IMU on board the missile Simulation results indicate that small miss distances can be achieved without the need for accurate alignment of the missile prior to launch

Control and guidance system

Abstract: A control and guidance system is described which allows vehicles of all types, machines and robots to be oriented exactly with respect to their environment or relative to one another with the aid of optical signals and optical sensors for the direction-dependent detection of such signals. The invention is explained with reference to numerous exemplary embodiments from aeronautics, road traffic and machinery construction. The figures in the drawing complement the description.

Plant operation guidance device

Abstract: PURPOSE:To realize the flexible operation guidance that can cope with the real time change of a plant by using an off-line computer suited to formation of a system knowledge data base and an on-line computer which excels in the follow-up properties against the process changes. CONSTITUTION:A plant operation guidance device consists roughly of an off-line computer system which works mainly for formation of a knowledge data base and the off-line computer system works to form a knowledge data base 6 via a man-machine system for an entire plant. In this respect, the base 6 and an inference engine 7 are described in such languages as an LISP, a PROLOG, etc., by which a system can be easily formed. Another constitution part is an on-line computer system connected to said off-line computer system by a transmission line. Thus, the titled computer system functions to secure the coexistence between a flexible operation guidance expert system and a proper operation guidance system that can cope with the plant changes.

Experiences in Developing an Intelligent Operator Guidance System

Abstract: Some expert systems are now moving from the protected environment of the laboratory into the real world. Many of the problems encountered are different from those experienced in prototype development. This paper presents some experiences in developing a certain class of expert system, the intelligent operator guidance system, currently progressing from prototype to production system. The use of real data for system development is stressed.

Lateral Guidance System Requirements Definition

Abstract: Institute of Transportation Studies University of CaIifornia, Berkeley PROGRAM ON ADVANCED TECHNOLOGY FOR THE HIGHWAY Lateral Guidance Systems Requirements Definition Robert E Parsons Wei-Bin Zhang PATH Research Report UCB-ITSPRR-88-l October 1988

An overview of area control systems and motor vehicle navigation/ route guidance developments in japan

Abstract: This paper describes the state of art and recent developments in area control systems of traffic signals and motor vehicle navigation/ route guidance systems in Japan. There are currently 74 cities which have area control systems in Japan. The manner of control is rather conventional and is basically of the traffic- adaptive program selection type. Three systems for navigation/ route guidance of motor vehicles have been proposed. CASCS is the pioneer system of dynamic route guidance in urban networks. RACS and AMTICS are recent proposals.

Adaptive guidance for an aero-assisted boost vehicle

Abstract: An adaptive guidance system incorporating dynamic pressure constraint is studied for a single stage to low earth orbit (LEO) aero-assist booster with thrust gimbal angle as the control variable. To derive an adaptive guidance law, cubic spline functions are used to represent the ascent profile. The booster flight to LEO is divided into initial and terminal phases. In the initial phase, the ascent profile is continuously updated to maximize the performance of the boost vehicle enroute. A linear feedback control is used in the terminal phase to guide the aero-assisted booster onto the desired LEO. The computer simulation of the vehicle dynamics considers a rotating spherical earth, inverse square (Newtonian) gravity field and an exponential model for the earth's atmospheric density. This adaptive guidance algorithm is capable of handling large deviations in both atmospheric conditions and modeling uncertainties, while ensuring maximum booster performance.

Guidance system for input item

Abstract: PURPOSE:To satisfactory perform the guidance of an input item, by switching a job input picture plane being displayed on a visual display device to a guidance picture plane. CONSTITUTION:In displaying the job input picture plane on a display device 11, a request for the guidance of the input item in inputting is inputted from a keyboard 12. A guidance display control means 2 reads a guidance data from a magnetic disk 14, and displays it on the device 11. An input item input control means 3 obtains the input of the input item guided in the name of a guidance picture plane in displaying on the device 11. A job picture plane re-display control means 4 re-displays the job input picture plane before displaying the guidance picture plane, and an input data in inputting. An input data display control means 5 displays the data inputted in displaying the guidance picture plane on the prescribed position of the job input picture plane corresponding to the input item. In such a manner, it is possible to satisfactorily guide the input item.

Joule-Thomson Cooling - An Overview

Abstract: This paper is concerned with the use of Joule-Thomson refrigerators in infrared detection systems such as thermal imagers, missile seekers, and guidance systems. Although the principle behind the minicooler is simple there exists a range of designs, either simple or complex, which cover many requirements from one-shot fast cool systems for missile guidance to systems requiring the minimum of logistic support and reliability for remote thermal imaging applications. The first step in examining the use of J-T minicoolers is to look at the applications and how each relates to the cryogenic system used.

The Evaluation of Route Guidance Systems

Abstract: BACKGROUND We were commissioned by the Transport and Road Research Laboratory to: "collaborate with the German government and their representatives who are responsible for conducting the LISB trial in Berlin in order to produce an agreed methodology, which is acceptable in both Germany and the UK, for assessing the automatic route guidance systems which will be provided in Berlin and London." The brief suggested a number of aspects to be included, and required detailed proposals, timescales and costs for implementation in London. 1.1.2 The background to the brief lies in decisions to introduce pilot automatic route guidance systems in the two cities. The principles of the systems are similar, and have been described in detail elsewhere (Jeffery, 1987). In brief, they involve : (i) a central computer which retains information on a specified road network, which is updated using real time information from the equipment users; (ii) infra red beacons at selected junctions which transmit information to equipped vehicles and receive information from those vehicles; (iii) in-vehicle equipment which includes a dead-reckoning system for position finding, a device for requesting guidance and specifying the destination, a micro-computer which selects the optimal route, and a display which indicates when a turn is required on the main network, and the compass direction and distance to the final destination; iv) transmission from the equipped vehicles of origin, requested destination, links used since passing the last beacon and, for each link, the time of entry and departure and time spent delayed. It is this travel time information which is used to update the central computer's knowledge of the best routes. (Continues..)

Guiding method for guidance and its detector

Abstract: PURPOSE:To obtain a guidance system which is easy to construct and maintain by detecting two kinds of markers and sending a signal which is modulated according to the kind by radio, and reproducing guidance information selected among plural pieces of sound-recorded guidance information based on time variation of the modulation as a sound and annunciating the information. CONSTITUTION:A detector (walking stick 5) detects markers B and sends a modulated signal B by radio. When a walker passes a point P, a signal that a guidance device 7 receives changes from the signal B to a signal A. For the purpose, the signal of a receiving antenna 6 is monitored to know the moment when the walker passes the point P and the direction of the passage. A logical processing circuit incorporated in the guide device 7 decides that right after the walker passes the point P, and desired guidance information is selected among pieces of recorded guidance information and sent from a transmitting antenna 8 by radio. This sent signal is received by a receiver and listened to as a sound. Markers are made preferably of bad conductor magnetic materials or metal and discriminated by variation in the inductance of a coil sensor.

Approach Trajectory Guidance for Maximum Concealment

Abstract: An energy-management concept is examined with a view to provision of a near-optimum maneuver guidance system for military aircraft tactical operations. The data thus obtained indicate that the Quiet Short-Haul Research Aircraft, as modeled in the aircraft-specific energy-rate tables, could fly the flight paths in question. The fuel-conservative guidance system's ability to minimize pop-up flight time and carefully coordinate the aircraft's controls for this performance-oriented requirement is demonstrated.