Showing papers on "Guidance system published in 2004"

Missile Guidance and Control Systems

Abstract: Contents 1 Introduction References 2 The Generalized Missile Equations of Motion 2.1 Coordinate Systems 2.1.1 Transformation Properties of Vectors 2.1.2 Linear Vector Functions 2.1.3 Tensors 2.1.4 Coordinate Transformations 2.2 Rigid-Body Equations of Motion 2.3 D'Alembert's Principle 2.4 Lagrange's Equations for Rotating Coordinate Systems References 3 Aerodynamic Forces and Coefficients 3.1 Aerodynamic Forces Relative to the Wind Axis System 3.2 Aerodynamic Moment Representation 3.2.1 Airframe Characteristics and Criteria 3.3 System Design and Missile Mathematical Model 3.3.1 System Design 3.3.2 The Missile Mathematical Model 3.4 The Missile Guidance System Model 3.4.1 The Missile Seeker Subsystem 3.4.2 Missile Noise Inputs 3.4.3 Radar Target Tracking Signal 3.4.4 Infrared Tracking Systems 3.5 Autopilots 3.5.1 Control Surfaces and Actuators 3.6 English Bias References 4 Tactical Missile Guidance Laws 4.1 Introduction 4.2 Tactical Guidance Intercept Techniques 4.2.1 Homing Guidance 4.2.2 Command and Other Types of Guidance 4.3 Missile Equations of Motion 4.4 Derivation of the Fundamental Guidance Equations 4.5 Proportional Navigation 4.6 Augmented Proportional Navigation 4.7 Three-Dimensional Proportional Navigation 4.8 Application of Optimal Control of Linear Feedback Systems with Quadratic Performance Criteria in Missile Guidance 4.8.1 Introduction 4.8.2 Optimal Filtering 4.8.3 Optimal Control of Linear Feedback Systems with Quadratic Performance Criteria 4.8.4 Optimal Control for Intercept Guidance 4.9 End Game References 5 Weapon Delivery Systems 5.1 Introduction 5.2 Definitions and Acronyms Used in Weapon Delivery 5.2.1 Definitions 5.2.2 Acronyms 5.3 Weapon Delivery Requirements 5.3.1 Tactics and Maneuvers 5.3.2 Aircraft Sensors 5.4 The Navigation/Weapon Delivery System 5.4.1 The Fire Control Computer 5.5 Factors In.uencing Weapon Delivery Accuracy 5.5.1 Error Sensitivities 5.5.2 Aircraft Delivery Modes 5.6 Unguided Weapons 5.6.1 Types of Weapon Delivery 5.6.2 Unguided Free-Fall Weapon Delivery 5.6.3 Release Point Computation for Unguided Bombs 5.7 The Bombing Problem 5.7.1 Conversion of Ground Plane Miss Distance into Aiming Plane Miss Distance 5.7.2 Multiple Impacts 5.7.3 Relationship Among REP, DEP, and CEP 5.8 Equations of Motion 5.9 Covariance Analysis 5.10 Three-Degree-of-Freedom Trajectory Equations and Error Analysis 5.10.1 Error Analysis 5.11 Guided Weapons 5.12 Integrated Flight Control in Weapon Delivery 5.12.1 Situational Awareness/Situation Assessment (SA/SA) 5.12.2 Weapon Delivery Targeting Systems 5.13 Air-to-Ground Attack Component 5.14 Bomb Steering 5.15 Earth Curvature 5.16 Missile Launch Envelope 5.17 Mathematical Considerations Pertaining to the Accuracy of Weapon Delivery Computations References 6 Strategic Missiles 6.1 Introduction 6.2 The Two-Body Problem 6.3 Lambert's Theorem 6.4 First-Order Motion of a Ballistic Missile 6.4.1 Application of the Newtonian Inverse-Square Field Solution to Ballistic Missile Flight 6.4.2 The Spherical Hit Equation 6.4.3 Ballistic Error Coef.cients 6.4.4 Effect of the Rotation of the Earth 6.5 The Correlated Velocity and Velocity-to-Be-Gained Concepts 6.5.1 Correlated Velocity 6.5.2 Velocity-to-Be-Gained 6.5.3 The Missile Control System 6.5.4 Control During the Atmospheric Phase 6.5.5 Guidance Techniques 6.6 Derivation of the Force Equation for Ballistic Missiles 6.6.1 Equations of Motion 6.6.2 Missile Dynamics 6.7 Atmospheric Reentry 6.8 Missile Flight Model 6.9 Ballistic Missile Intercept 6.9.1 Introduction 6.9.2 Missile Tracking Equations of Motion References 7 Cruise Missiles 7.1 Introduction 7.2 System Description<7.2.1 System Functional Operation and Requirements 7.2.2 Missile Navigation System Description 7.3 Cruise Missile Navigation System Error Analysis 7.3.1 Navigation Coordinate System 7.4 Terrain Contour Matching (TERCOM) 7.4.1 Introduction 7.4.2 De.nitions 7.4.3 The Terrain-Contour Matching (TERCOM) Concept 7.4.4 Data Correlation Techniques 7.4.5 Terrain Roughness Characteristics 7.4.6 TERCOM System Error Sources 7.4.7 TERCOM Position Updating 7.5 The NAVSTAR/GPS Navigation System 7.5.1 GPS/INS Integration References A Fundamental Constants B Glossary of Terms C List of Acronyms D The Standard Atmospheric Model References E Missile Classi.cation F Past and Present Tactical/Strategic Missile Systems F.1 Historical Background F.2 Unpowered Precision-Guided Munitions (PGM) References G Properties of Conics G.1 Preliminaries G.2 General Conic Trajectories References H Radar Frequency Bands I Selected Conversion Factors Index

Stated Preferences for Components of a Personal Guidance System for Nonvisual Navigation

Abstract: This article reports on a survey of the preferences of visually impaired persons for a possible personal navigation device. The results showed that the majority of participants preferred speech input and output interfaces, were will- ing to use such a product, thought that they would make more trips with such a device, and had some concerns about the cosmetic acceptability of a device and the use of a single or stereo headphone interface.

Performance Test Results of an Integrated GPS/MEMS Inertial Navigation Package

Abstract: This paper describes the design, operation and performance test results of a miniature, low cost integrated GPS/inertial navigation system (INS) designed for use in UAV or UGV guidance systems. The system integrates a miniaturized commercial GPS with a low grade Micro-Electro-Mechanical (MEMS) inertial measurement unit (IMU). The MEMS IMU is a small self-contained package (< 1 cu inch) and includes a triad of accelerometers and gyroscopes with additional sensors integrated for temperature compensation and baro pressure altitude aiding. The raw IMU data is provided through a serial interface to a processor board where the inertial navigation solution and integrated GPS/inertial Kalman filter is generated. The GPS/Inertial software integration is performed using NAVSYS’ modular InterNav software product. This allows integration with different low cost GPS chips sets or receivers and also allows the integrated GPS/inertial navigation solution to be embedded as an application on a customer’s host computer. This modular, object oriented architecture facilitates integration of the miniature MEMS GPS/INS navigation system for embedded navigation applications. Test results are presented in this paper showing the performance of the integrated MEMS GPS/INS navigation system when used to perform guidance for a small Unmanned Ground Vehicle (UGV). Data is provided showing the position, velocity and attitude accuracy when operating with GPS aiding and also for periods where GPS dropouts occur and alternative navigation update sources are used to bound the MEMS inertial navigation error growth.

Dynamic Lateral Entry Guidance Logic

Abstract: Lateral motion of an entry vehicle is controlled by the sign of its bank angle, determined by the entry guidance system. The conventional technique for changing the bank sign is based on prespecified threshold values in the heading error of the vehicle with respect to the landing site. A new automated lateral guidance logic is developed based on the crossrange, which is found to be a more suitable parameter than the heading error for lateral guidance. The present guidance logic determines the bank reversals by constantly evaluating information from the reference crossrange profile, current crossrange, and estimated actual lift-to-drag ratio. Near the end of the trajectory, a noniterative numerical predictor decides whether a final bank reversal is needed to null the heading error. This algorithm enables the entry guidance system to fly a wide range of missions and vastly different bank-angle profiles and provides reliable and good performance in the presence of significant aerodynamic modeling uncertainty. All of these tasks can be accomplished without requiring manual tuning of guidance parameters or using an excessive number of bank reversals. Extensive high-fidelity simulations with different mission scenarios and significant dispersions are presented to demonstrate the performance of the proposed method. I. Introduction T HE entry guidance system for a lifting entry vehicle controls the bank angle and angle of attack during the atmospheric flight from the entry interface at about altitude 120 km until the velocity decreases to Mach 2‐3 (Ref. 1). The guidance commands are generated by tracking a reference trajectory which is designed either in preflight planning, 1 or potentially on board, as recent efforts have attempted to achieve. 2−4 In the traditional approach, the reference to be tracked represents the desired longitudinal profiles as in the case of the shuttle, where the reference is a drag-acceleration-vs-velocity profile that equivalently defines the range-vs-energy condition. 1 Tracking the longitudinal profiles determines the magnitude of the bank-angle command. The sign of the bank-angle command, on the other hand, is changed to the opposite whenever the heading error with respect to the targeted landing site exceeds a prespecified threshold. This forced change of bank sign is referred to as bank-angle reversal. The traditional approach works well when the actual flight goes as planned in pre-mission analysis and the actual bank-angle magnitude remains close to the reference value. When the bank profile flown is significantly different, the bank-reversal threshold criterion will require adjustments, typically made through simulations. The situations where a very different bank-angle profile may be necessary include entry from a different orbit, landing at an alternate landing site, variations in entry conditions leading to much different downrange and crossrange, and contingency entry missions (such as on-demand entry and aborts) that are not planned. The recent advances in trajectory-planning algorithms would potentially allow on-board generation of a reference trajectory based on the actual conditions. However, the corresponding bank-angle profiles could be drastically different from the nominal one. Similar situations can develop in the presence of significant aerodynamic modeling mismatch, where flying even the nominal longitudinal profiles may necessitate a bank-angle profile considerably different

Bezier curve flightpath guidance using moving waypoints

Abstract: A flightpath guidance system and method is disclosed for using moving waypoints for a curved route plan such as a Bezier curve. The actual location of a vehicle and a leading target point along the path are used to provide commanded guidance of the vehicle along the path and to correct for disturbances from the intended route. Waypoints along the path may be moving with respect to the reference frame in which the vehicle is measured. Curved flightpath guidance using moving waypoints may be used for aerial rendezvous and refueling, multiple vehicle applications such as formation flying and battlefield formation grouping, and carrier landing. Further application includes air traffic control and commercial flight guidance systems.

Airborne-Managed Spacing in Multiple Arrival Streams

Abstract: A significant bottleneck in the current air traffic system occurs at the runway. Expanding airports and adding new runways will help solve this problem; however, this comes at a significant cost, financially, politically and environmentally. A complementary solution is to safely increase the capacity of current runways. This can be achieved by precise spacing at the runway threshold with a resulting reduction in the spacing buffer required under today s operations. At the NASA Langley Research Center, the Advanced Air Transportation Technologies (AATT) Project is investigating airborne technologies and procedures that will assist the pilot in achieving precise spacing behind another aircraft. This new spacing clearance instructs the pilot to follow speed cues from a new on-board guidance system called Airborne Merging and Spacing for Terminal Arrivals (AMSTAR). AMSTAR receives Automatic Dependent Surveillance-Broadcast (ADS-B) reports from the leading aircraft and calculates the appropriate speed for the ownership to fly in order to achieve the desired spacing interval, time or distance-based, at the runway threshold. Since the goal is overall system capacity, the speed guidance algorithm is designed to provide system benefit over individual efficiency. This paper discusses the concept of operations and design of AMSTAR to support airborne precision spacing. Results from the previous stage of development, focused only on in-trail spacing, are discussed along with the evolution of the concept to include merging of converging streams of traffic. This paper also examines how this operation might support future wake vortex-based separation and other advances in terminal area operations. Finally, the research plan for the merging capabilities, to be performed during the summer and fall of 2004 is presented.

Guidance policies in the knowledge society : trends, challenges and responses across Europe : a CEDEFOP synthesis report

Abstract: Based on a questionnaire designed by the Organisation for Economic Cooperation and Development (OECD), this report draws on the responses of experts from a large number of European countries who participated in the survey on policies for career guidance. The importance of career guidance is becoming more widely acknowledged, and is recognised as a means to achieve four public policy goals - lifelong learning, social inclusion, labour market efficiency, and economic development. The aim of the report is to provide an account of significant trends, challenges and issues, as well as strengths and weaknesses of information and guidance systems and policies in Europe. Successful or innovative practices are identified, with examples given from participating countries. It is hoped that this will assist policy-makers and practitioners to compare and review their own procedures, as well as providing a clear and useful overview of the research. The report is comprised of a number of chapters: Introduction - putting guidance on the agenda; Defining and interpreting guidance in Europe; Guidance and the challenges for public policy; Meeting the guidance needs of young people; Meeting the guidance needs of adults; Widening access through more innovative and diverse delivery; Providing career information more effectively; Staffing career guidance; Funding career guidance; Improving strategic leadership; Conclusions. A similar synthesis of the research, previously produced in one short paper (Watts and Sultana, 2003), has been included as an annex to this document.

Conceptual Design of an AUV Equipped with a Three Degrees of Freedom Vectored Thruster

Abstract: The early stages of design and simulation of a new concept, autonomous underwater vehicle equipped with vectored thrusters is investigated. The opportunity to increase the research effort in innovative solutions for AUV propulsion and guidance systems is related to the state-of-the-art analysis. The dynamics of submersibles is briefly recalled, to justify the choice to equip the vehicle with a three degrees of freedom mechanism capable to orient both the propeller and the stabilising tail-fins. The vehicle presented has to be considered as a “concept submersible”, that needs further improvements and tuning to become a completely running test-bench for navigation system assessment. A tailored simulation package and results are also described, in order to perform a wide ranging numerical test campaign to foresee life cycle behaviour.

Development of an integrated fuzzy-logic-based missile guidance law against high speed target

Abstract: How to develop a novel missile guidance law that can act effectively against very high speed incoming targets, such as ballistic missiles, has been a major concern in the defense technique. It has been unveiled recently in the literature that the most effective way for a lower speed interceptor to successfully engage an incoming target with very high speed is to limit the aspect angle between the missile and target flight path to within 180/spl deg/ plus or minus few degrees. On the basis of this requirement, a new integrated fuzzy guidance law is developed in this paper against very high-speed maneuverable targets on three-dimensional space. An integrated fuzzy type guidance law is explored for midcourse and terminal phases. It is shown that the integrated guidance scheme offers excellent tracking performance as well as performance sensitivity with respect to some parametric variations.

An Automotive Lane Guidance System

Abstract: Automotive lane guidance systems, usually referred to as Lane Keeping Aid or Lane Keeping System, are designed to prevent or warn the driver of lane departure. They typically use a buzzer to alert the driver or a steering wheel torque to actually steer the vehicle back into the center of the lane. Emergency Lane Assist (ELA) combines conventional lane guidance systems with a threat assessment module that tries to activate the lane guidance interventions according to the actual risk level of lane departure. The goal is to only prevent dangerous lane departure manoeuvres.Such a threat assessment algorithm is dependent on detailed information about the vehicle surroundings, i.e., positions and motion of other vehicles, but also information about road and lane geometry parameters such as lane width and road curvature. The thesis demonstrates that the lane estimate can be improved by using an integrated filter that combines information from object and lane tracking. This is done by introducing a road aligned, curved coordinate system which also brings other advantages when it comes to modelling and prediction.Evaluation of the integrated tracking system has been carried out on real data and the ELA decision algorithm has been tested in a demonstrator. ELA successfully distinguishes between dangerous and safe lane changes ona small set of test scenarios and is, if activated, able to take control of the vehicle and put it in a safe position in the original lane.

Global -exponential way-point manoeuvering of ships

Abstract: This paper considers way-point manoeuvering in three degrees of freedom (surge, sway and yaw). A line-of-sight motivated control law that globally� -exponentially stabilizes an underactuated ship is derived using output redefinition and cascaded systems theory. The control law development is based on a general nonlinear ship model with surge propeller force and rudder moment as control inputs. Simulation results on a full scale model of a supply vessel are presented. I. INTRODUCTION The route of a ship is usually specified in terms of way- points (1). The way-points are selected taking into account a number of features like weather conditions, obstacle avoid- ance and mission planning. Each way-point is defined in Cartesian coordinates+{l>|l, forl@4===s . The reference trajectory is then made up by straight lines connecting the s way-points. When the ship reaches a prescribed circle, the circle of acceptance, about way-point l, the reference trajectory is switched to the straight line connecting way- points l and l.4. Alternatively, circle arcs connecting the straight lines can be used to define the desired turn at each way-point. In this paper we consider the problem of designing a controller that makes the ship follow the straight lines between way-points, and at the same time controls the forward speed to a constant desired speed xg , i.e. we consider a way-point manoeuvering control problem. Conventional ships are usually equipped with one or two main propellers for forward speed control, and rudders for course control. Even if equipped with side thrusters, these will not give a significant force at transit speeds. This means that we only have independent controls in two degrees of freedom (DOF), surge and yaw, while we seek to control all three degrees of freedom (surge, sway and yaw) of the ship. The path following, tracking and manoeuvering problems are hence underactuated control problems. In conventional way-point guidance systems the output space is reduced such that the number of outputs equals the number of control inputs, and in this way a fully actuated control problem is obtained. It is most often the yaw angle and surge velocity that are controlled. The desired yaw angle#g is then usually chosen using a line- of-sight (LOS) algorithm, while the desired forward speed is constant. Recent research, however, aims at controlling all 3DOF of the ship using only the two available control inputs. Furthermore, while conventional way-point guidance

Low-altitude flight guidance system, warning system for low-altitude flight guidance, warning generator for low-altitude flight guidance and method for low-altitude flight guidance

Abstract: A low-altitude flight guidance system for an aircraft including a warning generator that generates a warning based upon a predicted position. The system further including a first sensor system having a terrain database and a calculation module that determines a current position of the aircraft with respect to terrain stored in the terrain database and that determines a reference altitude h DB of the terrain at the current position. The system further includes a second sensor system and a module that determines a predetermined flight altitude difference Δh F at the predicted position and terrain data in a region U of the predicted position. Moreover, the system includes an altitude prediction module that predicts an altitude and forwards the predicted altitude to the warning generator. The warning is based upon the aircraft reaching, approaching, or exceeding a warning altitude limit, and the altitude prediction module determination for the predicted position is based upon a prediction set point. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

GPS receiver with autopilot and integrated lightbar display

Abstract: A system for controlling a mobile machine is disclosed. In one embodiment, the system comprises an integrated guidance system coupled with a steering component. The integrated guidance system comprises a position determining system for determining the geographic position of the mobile machine. A guidance system coupled with the position determining system is for determining a deviation of the mobile machine from a desired direction. The integrated guidance system also comprises a display coupled with the guidance system for visually indicating a deviation from a desired direction and a steering interface for controlling the steering component. The steering component automatically controls the steering mechanism of the mobile machine in response to a steering command generated by the steering interface. In embodiments of the present invention, the position determining system, the guidance system, the display, and the steering interface are disposed within a housing.

Route guidance system, method, and program

Abstract: PROBLEM TO BE SOLVED: To provide a route guidance system and the like which improve safety by reducing a number of movements of a driver's line of sight and enable the driver to reliably recognize a travel route to follow without a sense of incongruity by an image of a virtual guidance vehicle. SOLUTION: The route guidance system is a route guidance system for guiding a vehicle to a set destination and includes both a guidance vehicle display means for superposing and displaying the virtual guidance vehicle 46, which travels ahead of the vehicle while keeping a prescribed distance between the two vehicles according to the vehicle's speed, on an actual landscape being visually recognized by the vehicle's driver and a display altering means for altering a display location of the virtual guidance vehicle in such a way as to lengthen the distance between the two vehicles when the vehicle's speed is raised. COPYRIGHT: (C)2005,JPO&NCIPI

Assessment of a GPS Guided Spinning Projectile Using an Accelerometer -Only IMU

Abstract: This paper describes the system design and a preliminary performance assessment of a Global Positioning System (GPS) guided spinning projectile known as the Autonomous Naval Support Round (ANSR). The ANSR is a rolling 5 inch gun launched rocket assisted guided projectile being considered for development by the US Navy that utilizes the GPS and a gyro -less “accelerometer only” inertial measurement unit (AO IMU) for guidance and navigation purposes. The ANSR guidance, navigation and control (GNC) concept (initia lly proposed by NSWC Dahlgren) is based on being able to exploit commercial off the shelf components (COTS) for lower cost, while providing a projectile with an extended range capability. The proposed GNC concept for ANSR is based on using GPS measurement s to provide the onboard guidance system with position and velocity states and using a Forward Integrated Terminal States (FITS) guidance policy to guide the projectile to stationary ground based targets. A traditional Inertial Navigation System (INS) is n ot used. This is in contrast to previous assessment studies which assume an integrated GPS/INS system in a tightly coupled configuration. The ANSR functions with an open loop autopilot that generates deflection commands for a single pair of canards. The pe rformance analysis for this paper is done using a six degree of freedom simulation, and the primary metric used for the terminal navigation performance is the circular error probable (CEP).

Variable structure-based nonlinear missile guidance/autopilot design with highly maneuverable actuators

Abstract: In this brief, we propose a variable structure based nonlinear missile guidance/autopilot system with highly maneuverable actuators, mainly consisting of thrust vector control and divert control system, for the task of intercepting of a theater ballistic missile. The aim of the present work is to achieve bounded target interception under the mentioned 5 degree-of-freedom (DOF) control such that the distance between the missile and the target will enter the range of triggering the missile's explosion. First, a 3-DOF sliding-mode guidance law of the missile considering external disturbances and zero-effort-miss (ZEM) is designed to minimize the distance between the center of the missile and that of the target. Next, a quaternion-based sliding-mode attitude controller is developed to track the attitude command while coping with variation of missile's inertia and uncertain aerodynamic force/wind gusts. The stability of the overall system and ZEM-phase convergence are analyzed thoroughly via Lyapunov stability theory. Extensive simulation results are obtained to validate the effectiveness of the proposed integrated guidance/autopilot system by use of the 5-DOF inputs.

Aircraft formation/refueling guidance system

Abstract: An aircraft formation/refueling guidance system guides a follower aircraft relative to a leader aircraft. A datalink provides a position hold and a bias command from the leader aircraft to the follower aircraft. An optical tracker onboard the follower aircraft takes an image of the leader aircraft when receiving the hold command, tracks the leader aircraft using the image, and provides optical tracker movement outputs. A resolver resolves the optical tracker movement outputs to provide resolver control signals. A vernier control receives the bias command to change a position of the follower aircraft by biasing the resolver control signals with a bias signal. A sum circuit connected to the resolver and to the vernier control receives the resolver control signals and the bias signal to provide a sum circuit output signal. An autopilot and autothrottle receives the sum circuit output signal and the position hold command to control the follower aircraft.

Robust control of a platoon of underwater autonomous vehicles

Abstract: Effective control systems for a variety of underwater autonomous vehicles have been developed and are in use. These systems generally assume the vehicle is operating independently of other nearby vehicles. However, there is recent and growing interest in the coordinated control of a platoon of vehicles acting cooperatively to achieve an objective that a single vehicle operating alone cannot achieve. This paper presents the design of a robust multivariable controller for decentralized leader-follower control of a platoon of autonomous underwater vehicles. A three degree-of-freedom model of the REMUS underwater vehicle is used as an example case for control in a plane. The design is based on Linear Quadratic Gaussian regulator theory with Loop Transfer Recovery. A way point guidance system is used for lead vehicle navigation. Follower vehicles maintain specified range and bearing to adjacent vehicles. The resulting control system is used in a computer simulated search for randomly distributed mines. A three vehicle fleet is used to demonstrate superiority, in terms of area coverage and elapsed time, over a single vehicle search. Simulations are performed both with and without ocean current disturbances. A unique formation swap maneuver is introduced to make an efficient 180 degree turn in a mow-the-lawn type multivehicle search

Flight Test Results of an Adaptive Guidance System for Reusable Launch Vehicles

Abstract: For next generation Reusable Launch Vehicles (RLVs), reconfigurable control, adaptive guidance, and on-line trajectory-command reshaping will often be required to recover the mission in the face of a major anomalous event such as an effector failure. An adaptive guidance system that works in conjunction with a reconfigurable controller and an autonomous trajectory command reshaping algorithm is presented. The guidance law utilizes a backstepping architecture to generate pitch rate commands that drive the inner-loop control system. Under extreme failure conditions the control surfaces can saturate in an attempt to meet commanded moments. In these cases, the guidance feedback gains are reduced to preserve stability margins in the guidance loops. In addition, simulation and flight test results of the complete reconfigurable control/adaptive guidance/trajectory reshaping system are presented for a simulated X-40A RLV. The Total In- Flight Simulator research aircraft was utilized to flight test the X-40A system under a variety of failure conditions. This work was completed in conjunction with the Air Force Research Laboratory's Integrated Adaptive Guidance & Control (IAG&C) program. Both simulation and flight test results indicate the major benefits of the new system. With on-line trajectory reshaping, the vehicle is able to achieve a safe touchdown, whereas the vehicle is lost without trajectory reshaping.

Aerial chemical application and control method

Abstract: A chemical distribution control and guidance system operates for controlling the distribution of airborne product via an aircraft passing over a target. A weather station is positioned at various altitudes for use in determining an appropriate aircraft altitude for distributing the chemical to the target. A second weather station positioned near the target transmits weather data in real time to a central communications station and the aircraft for providing guidance in accurately, safely and effectively distributing chemicals onto the target.

A new nonlinear control for vehicle in sliding conditions: application to automatic guidance of farm vehicles using RTK GPS

Abstract: Since Global Navigation Satellite systems are able to supply very accurate coordinates of a point (about 2 cm with a RTK GPS), such a sensor is very suitable to design vehicle guidance system. It is especially the case in agricultural tasks where a centimeter precision is often required (seeding, spraying,...). To answer to growing high precision agriculture principle demand, several control laws for automated vehicle guidance relying on this sensor have been developed. Such guidance systems are able to supply an acceptable steering accuracy as long as vehicle does not slide (path tracking on even ground with good adherence properties...), what alas inevitably occurs in agricultural tasks. Several principles are here presented to steer vehicle whatever properties of ground and path to be followed are. In this paper a new extended kinematic model with sliding accounted is presented which allows describing vehicle dynamics in all guidance conditions. Via this model a new nonlinear control law can be designed, which integrates sliding effects. Its capabilities are investigated through simulations and experimental tests.

Lambert Guidance Routine Designed to Match Position and Velocity of Ballistic Target

Abstract: A three-degree-of-freedom interceptor missile simulation designed to rendezvous with a ballistic target is presented. The guidance scheme is designed to match the position and velocity of a ballistic target so that the interceptor will follow the target after the rendezvous. The guidance routine uses Lambert guidance to control the missile during the boost phase and put it on course to meet the ballistic target trajectory. After a long ballistic coast phase, shortly before rendezvous with the ballistic target, a short fourth-stage burn is scheduled to match the velocity of the ballistic target. The two-dimensional Lambert guidance equations are generalized to a three-dimensional coordinate system with the appropriate transformation matrix. The derivation of the equations for the miss distance created by the ∆V maneuver and required modifications to Lambert guidance are presented. Powell’s method is used to optimize the missile time of flight to reduce the maneuver ∆V requirements. The missile simulation is used to produce several trajectories and explore the ∆V requirements as a function of downrange and crossrange launch position of the interceptor.

Monitoring of a free space for motor vehicles

Abstract: The maneuvering of a road vehicle so as to avoid collision with objects, eg reversing into a garage [13] uses processed images from a digital camera. The guidance system generates virtual corridor surfaces [16] that ensure that the vehicle avoids contact with real surfaces as the doorway [14] is approached. The walls are updated as the vehicle moves.

Lead Route Guidance System, Portable Route Lead Guidance Device, And Program

Abstract: A lead route guidance system capable of displaying route guidance not causing the user to be confused by the difference between the line of vision and the route guidance image, a portable route lead guidance device, and program are provided. The lead route guidance system comprises route storage means storing a route from a start point to a destination, route guidance image creating means for creating a route guidance image (24) containing a route image (22) for specifying the route and a lead image (23) for leading the route by displaying a lead position on the route ahead of the current position of the user, a display screen (11) for displaying thereon the route guidance image (24), walk detecting means for detecting walk of the user, and lead position updating means for updating the lead position depending on the walk of the user when the walk of the user is detected.

Advanced missile guidance system against a very high speed maneuvering target

Abstract: This paper studies the guidance law in the homing phase of the advanced missile guidance system, which is characterized by intercepting a very high speed maneuvering target with a relatively low speed surface-teair missile. The objective of this study is to investigate the cause of the aspect angle constraint at lockon, in order to extend the successful range of the aspect angle, where small miss distance is achievable. First, the successful lockon conditions for the missile are investigated, in regard to the interception geometries against maneuvering targets at various altitudes. Our previous study showed that, in order to achieve a small miss distance against a non-maneuvering target far faster than a missile, the aspect angle at lockon should be near 180". The current study showed that the situation is almost the same against a maneuvering target, except that the miss distance becomes small when a target maneuvers towards a missile and becomes large when it maneuvers away from a missile particularly at a high altitude(15km). Second, two types of modified proportional navigation guidance laws in the homing phase are studied in order to investigate the cause of the aspect angle constraint at lockon. The simulation results show that modified proportional navigation guidance laws with compensation of target lateral acceleration or missile velocity change little relax the aspect angle constraint. Third, the effect of the time-to-go estimation error, which induces the prediction error of the interception point, on the aspect angle constraint is studied. The simulation results show that, this time-to-go estimation error greatly changes the successful aspect angle range for a missile, therefore the reduction of the missile time constant is the prime factor in order to relax the constraint.

Miss Distance Error Analysis of Exoatmospheric Interceptors

Abstract: A miss distance error analysis of exoatmospheric interceptors with liquid divert thrusters in endgame is presented. The analysis relates miss distance uncertainty to 1) infrared/electrooptic seeker noise, 2) seeker latencies caused by image processing and motion compensation and integration to detect the target on the focal plane, 3) seeker scan angle measurement errors of gyro, 4) range error or time-to-go error, and 5) filtration of all these errors through a Kalman filter for estimating the line-of-sight (LOS) rates. With the relationships developed, the missile designer/analyst can predict a probable miss distance with the hardware parameters of the selected divert thrusters and sensor suite, as well as software parameters of the selected guidance policy. The analyst can also arrive at the LOS rate estimation accuracy requirements about the azimuth and elevation axes, to be achieved by a tracking Kalman filter for specified miss distance statistics. The analysis provides insight and predicts reliably the miss distances expected from Monte Carlo simulations and hardware-in-the-loop laboratory tests. I. Introduction M ISS distance error analysis of air missiles seems to be well understood, 1,2 but that of exoatmospheric interceptors equipped with infrared sensors and liquid divert thrusters appears to be lagging behind. To be sure, Refs. 3‐6 provide a system engineer design tools to arrive at hardware/software requirements for exoatmospheric interceptors to meet a specific miss or hit accuracy without the use of an elaborate trajectory simulation. However, these references do not specifically address unique features of exoatmospheric interceptors with liquid propulsion systems. This paper attempts to fill this gap.

Guidance system and navigation method

Abstract: The invention relates to a navigation method for a pedestrian zone in public buildings, building complexes and traffic zones that comprise a plurality of destinations interlinked by traffic routes According to said method, continuous optical guidance lines are disposed along the traffic routes These guidance lines are associated with a destination, terminate at the associated destination and can be easily distinguished The guidance lines are provided with unambiguous optical direction-indicating features that point into the direction of the destination associated therewith The guidance lines are particularly remote-controlled and combined from partially selectively activated display devices Remote control is especially carried out by a control center via a network to which the controllers controlling the display devices are connected Information terminals are provided at well accessible locations and users can be identified and user data accessed at these terminals, especially in combination with an information system that outputs user-specific information at selected locations of the buildings, traffic routes and destinations Users can be identified by means of electronic data carriers such as transponders that can be contactlessly queried