Showing papers on "Guidance system published in 1987"

Adaptive tracking vision and guidance system

Abstract: An adaptive tracking vision and guidance system for use with robot systems includes a structured light vision system and an expert system based look ahead feature tracker. The adaptive tracking vision system may be used to track a feature on which the robot is to operate and to supply guidance information in real time to the robot or to an adaptive stage on the robot arm train. The vision system may be a structured light system capable of scanning a relatively large window, and a control computer. The feature tracker includes an expert system software package and interface packages for the robot controller, host computer, vision camera and operator console. The vision system does an initial search to locate a feature based on a priori knowledge of characteristics of the feature. Then the system tracks the feature by scanning ahead, adaptively planning future scans, predicting the feature path and choosing the data to be used to reduce processing time. The system can supply guidance information to an adaptive stage controlling an end effector tool so that the robot can perform the desired operation precisely on the feature. If the feature is lost while scanning ahead, the vision system does a recovery search to relocate the feature, including switching to alternative mapping systems if necessary. If the feature cannot be recovered a signal is given to the operator.

A real-time guidance system for an autonomous vehicle

Abstract: A real-time system for the control of an autonomous vehicle consisting of a nested hierarchy of control modules is described. The focus is on the PILOT module which provdies the real-time guidance of the system. It is responsible for the generation and tracking of dynamically feasible trajectories which follow the generally planned path and avoid local obstacles. The PILOT operation is based on a combination of simple rules and heuristic search. The state space consists of two parts: the lower level state space which represents the model of the world as a set of relationships among the units of vehicle state variables representing steering, acceleration, and velocity, as well as positions of obstacles, and the upper level state space where the relationships among generalized objects are represented as rules. Rules provide simple elementary maneuvers, and are applied when the upper level situation is easily recognized. Otherwise the situations are handled by the lower level search. Example runs of the vehicle are simulated to demonstrate the complexity of behavior. The algorithm has also been tested on a gas powered dune buggy developed at Drexel University.

An Optimal g-Guidance Scheme for Satellite Launch Vehicles

Abstract: A closed-loop steering logic based on an optimal (2-guidance is developed here. The guidance system drives the satellite launch vehicle along a two- or three- dimensional trajectory for placing the payload into a specified circular orbit. The modified g-guidance algorithm makes use of the optimal required velocity vector, which minimizes the total impulse needed for an equivalent two-impluse transfer from the present state to the final orbit. The required velocity vector is defined as velocity of the vehicle on the hypothetical transfer orbit immediately after the application of the first impulse. For this optimal transfer orbit, a simple and elegant expression for the Q-matrix is derived. A working principle for the guidance algorithm in terms of the major and minor cycles, and also for the generation of the steering command, is outlined.

Magnetic guidance of autonomous vehicles (part 2)

Abstract: This paper describes an extension of some magnetic guidance work reported earlier. The extension consists of determining the magnetic moment and orientation of a bottom resting magnetic anomaly as well as the vertical distance to the anomaly. This information should lower the false alarm probability of an operational magnetic guidance system. Increasing interest in underwater autonomous vehicles has resulted in a search for suitable guidance systems. Magnetic techniques could provide supplementary guidance for autonomous vehicles that need occasional precise position fixes to update their standard navigational systems, or that want to return to a particular spot on the ocean bottom with great accuracy. A small permanent magnet resting at a precisely known spot on the ocean's bottom, or naturally occurring key features in a magnetic survey of the bottom, could provide the necessary magnetic signal. An adaptive search approach to magnetic guidance is promising. In adaptive search, the location of each successive search pass is determined by information gathered on the previous pass. Computer simulation results show that three search passes are usually sufficient to locate the center of the magnetic anomaly to within several feet. The favored sensor configuration consists of a scalar magnetometer whose outputs are successively subtracted along the path of sensor motion to form an approximation to the spatial gradient of the sensor's output. Data interpretation for this technique appears simple enough to be done automatically by either algorithmic or artificial intelligence techniques. Using the adaptive search technique to accurately position the vehicle, and placing a second magnetometer directly above the first, the magnitude and orientation of the anomaly's magnetic moment can be measured. The vertical distance to the anomaly can also be determined. Thus, if an independent altimeter is available, object vertical height above or below the bottom can be measured. This information would be useful in determining that the correct object of interest has been located.

Careers guidance services within the European Community: contrasts and common trends

Abstract: The main features of the guidance systems for young people aged 14–25 in the Member-States of the European Community are outlined. A number of important differences are analysed: in terms of the main location of guidance services, the focus of such services, the range of guidance activities, the structure of financing, and the professional identity of those occupying guidance roles. At the same time, three common trends are identified which have a general if not universal validity across the Member-States: the view of educational and vocational guidance as a continuous process; the emergence of a more open professional model; and the greater emphasis on the individual as an active agent, rather than as a passive recipient, within the guidance process.

Ground guidance system for an autonomous vehicle

Abstract: The present invention relates to a system for the ground guidance of an independent vehicle (1) with wheels (11) driven by motorisation means, equipped with steering and with a detection system (91, 92) interacting with a reference (2) linked to the ground, characterised in that the system comprises an odometric sensor (3) linked to the vehicle and equipped with free wheels (51 and 52) and with coders (6, 7, 8) connected to an on-board processing and computing unit controlling the motorisation of the wheels and the steering, and in that the reference (2) consists of a plurality of separate localised references (2) arranged at the vehicle stopping points.

Towards a Technology Assessment of Highway/Navigation and Route Guidance

Abstract: There are now a wide variety of route guidance systems available, both automated and non-automated. There are navigation aids, route guidance and route control. The technology has reached and advanced stage and is on the market in some forms. Needed is an assessment of driver response and network behavior to evaluate the technical requirements and limitations. A thorough economic analysis needs to be undertaken to clarify cost effectiveness implications. Policy analyses are needed to look at the issues of liability and public acceptance.

Microwave landing system for use on a back course approach

Abstract: Independent guidance and monitoring integrated into an MLS landing system and a scaled-down MLS take-off or missed approach guidance system useable at small airports. An added fixed beam precision guidance system is integrated into the MLS time sequence format. The fixed beam guidance system is based upon the concept of using paired fixed overlapping beams, sequentially radiated by different fixed antennas (80 and 81), oriented to left and right of a prescribed guidance path. The paired beams overlap at the prescribed guidance path in such a manner that an aircraft departing or making a missed approach on such path will intercept equal signal intensities to indicate an on-course condition. Conversely, when the aircraft is off-course to one side of the prescribed path, it will intercept a stronger signal intensity for the fixed guidance beam which is directed to that side of the prescribed path and a weaker signal intensity for the fixed beam which is directed to the other side of the prescribed path.

Homing device system for missile

Abstract: A guidance system for guiding a missile to a target including an array of photosensitive elements arranged orthogonally to the axis of the missile, a scanning arrangement for enabling scanning of the array of photosensitive elements by means of an optical system, and a target detecting arrangement for controlling the field and the pace of scanning executed by the scanning arrangement so that the field of scanning is smaller and the pace of scanning is greater after detecting a target than before target detection.

Guidance simulation and test support for differential gps (global positioning system) flight experiment

Abstract: Three separate tasks which supported the test preparation, test operations, and post test analysis of the NASA Ames flight test evaluation of the differential Global Positioning System (GPS) are presented. Task 1 consisted of a navigation filter design, coding, and testing to optimally make use of GPS in a differential mode. The filter can be configured to accept inputs from external censors such as an accelerometer and a barometric or radar altimeter. The filter runs in real time onboard a NASA helicopter. It processes raw pseudo and delta range measurements from a single channel sequential GPS receiver. The Kalman filter software interfaces are described in detail, followed by a description of the filter algorithm, including the basic propagation and measurement update equations. The performance during flight tests is reviewed and discussed. Task 2 describes a refinement performed on the lateral and vertical steering algorithms developed on a previous contract. The refinements include modification of the internal logic to allow more diverse inflight initialization procedures, further data smoothing and compensation for system induced time delays. Task 3 describes the TAU Corp participation in the analysis of the real time Kalman navigation filter. The performance was compared to that of the z-set filter in flight and to the laser tracker position data during post test analysis. This analysis allowed a more optimum selection of the parameters of the filter.

Operation guidance system

Abstract: PURPOSE:To improve a using rate by preparing plural operation guidances in plural languages to an automatic teller machine and allowing operators to select a specific one prior to operation. CONSTITUTION:Besides a general Japanese guidance message 4, the necessary number of guidances written in other languages are displayed below the Japanese one as the display contents of the guidance display part 2 of the automatic teller machine (ATM) 1. For instance, if it is the guidance in English 5, the operator presses a tenkey 7. If other languages 6 are wanted, a key 8 among the tenkey 7 is pressed to selectively display. Thus the operator selects the prescribed transaction through a transaction selection screen, and afterwards he can keep transactions in the same manner as according to the Japanese guidance.

Obstacle Detection Algorithms for Low Altitude Flight

Abstract: This paper describes an approach to collision avoidance for rotorcraft flying at low altitudes. The method is based on extracting information from passive image-based sensors. These methods can be used to alert a pilot about obstacles and provide inputs to navigation and guidance systems for further processing.

Sensor and Guidance Technology Related to Mobile Robots.

Abstract: : In case of a national mobilization, the Army needs a technique to construct training facilities rapidly without using a large pool, of skilled labor. This can be achieved by borrowing robot technology used to increase productivity in manufacturing. However, most construction activities require mobility. This report contains a list of requirements for mobile robot sensor and guidance systems for mobilization construction. An evaluation of the current state of the art in mobile robot sensor and guidance systems is included. The report then looks at the feasibility of integrating current components to form a practical sensor and guidance system for mobile construction robots. Finally, the report makes recommendations for basic research needed in this area. (author)

Weapon guidance system

Abstract: The centroid of the discrete components forming the overall radar return from a target onto which a homing weapon is being guided may not coincide with a desired aimpoint on the target. Herein proposed is the discrimination and comparison of returns from different portions of the weapon sensor's field-of-view, i.e. different portions of the target and guidance of the weapon in dependence upon the relative values of the differences between those returns. As a result, the weapon can hit say the centre of a tank turret roof rather than the probably heavily armoured area forward of the turret roof.

Vehicular navigation and route guidance systems: technology and applications

Abstract: This paper reviews the status of in-vehicle navigation and route guidance systems and describes past, present and future systems. It also reviews potential applications for vehicular navigation and route guidance systems, and examines their possible benefits and future impact on the roadway transportation system.

Vehicle location and navigation in the urban environment

Abstract: This paper discusses the system design of vehicle location navigation, and route guidance systems.

Guidance system for automatically guiding a missile towards a target

Abstract: The guidance system comprises an optical system carried by the missile and which is capable of forming optical images of the landscape in which the missile is travelling. There is a set of photosensitive elements carried by the missile which are arranged to receive an output beam of the optical system and convert the optical images into electrical images. Also included is a target detecting arrangement for detecting a target in the electrical images. The set of photo- sensitive elements is constituted by at least one linear array of photosensitive elements placed orthogonally to the axis of the missile. A scanner is carried by the missile for scanning the output beam of the optical system over the array in a direction orthogonal to the array.