Showing papers on "Guidance system published in 2006"

Adaptive Terminal Guidance for Hypervelocity Impact in Specified Direction

Abstract: The problem of guiding a hypersonic gliding vehicle in the terminal phase to a target location is considered. In addition to the constraints on its final position coordinates, the vehicle must also impact the target from a specified direction with very high precision. The proposed 3-dimensional guidance laws take simple proportional forms. The analysis establishes that with appropriately selected guidance parameters the 3-dimensional guided trajectory will satisfy these impact requirements. We provide the conditions for the initial on-line selection of the guidance law parameters for the given impact direction requirement. The vehicle dynamics are explicitly taken into account in the realization of guidance commands. To ensure high accuracy in the impact angle conditions in an operational environment, we develop closed-loop nonlinear adaptation laws for the guidance parameters. We present the complete guidance logic and associated analysis. Simulation results are provided to demonstrate the effectiveness and accuracy of the proposed terminal guidance approach. I. Introduction Recent interests in developing on-demand global-reach payload delivery capability have brought to the forefront a number of underlying technological challenges. Such operations will involve responsive launch, autonomous entry flight, and precision terminal maneuvers. In certain scenarios the mission requirements call for the payload to impact the target location from a specific direction with supersonic speed. One example is to impact the target in a direction perpendicular to the tangent plane of the terrain at the target. The terminal guidance system will be responsible for directing the vehicle to the target and achieving the desired impact direction. The impact precision requirements under the scenarios considered are very high and stringent. For instance, the required Circular Error Probable (CEP) of the impact distance is just 3-meter. 1 The errors of the impact angles are desired to be within 0.5 deg. The very high speeds throughout the terminal phase only make it considerably more difficult to achieve these levels of precision. Yet cost considerations dictate that the terminal guidance algorithm should be relatively simple and computationally tractable for real-time operations. While a number of guidance methods can guide the vehicle to the target, not many address the unique need for impact from a specific direction. One method that can is the so-called “dive-line” guidance approach in Ref. 2. In this method one or more lines intersecting the Earth are established. The final dive-line intersects the target, and its direction can be set to the desired direction. The vehicle’s velocity vector is

High accuracy path tracking for vehicles in presence of sliding: Application to farm vehicle automatic guidance for agricultural tasks

Abstract: When designing an accurate automated guidance system for vehicles, a major problem is sliding and pseudo-sliding effects. This is especially the case in agricultural applications, where five-centimetre accuracy with respect to the desired trajectory is required, although the vehicles are moving on slippery ground. It has been established that RTK GPS was a very suitable sensor to achieve automated guidance with such high precision: several control laws have been designed for vehicles equipped with this sensor, and provide the expected guidance accuracy as long as the vehicles do not slide. In previous work, further control developments have been proposed to take sliding into account: guidance accuracy in slippery environments has been shown to be preserved, except transiently at the beginning/end of curves. In this paper, the design of this control law is first recalled and discussed. A Model Predictive Control method is then applied in order to preserve accuracy of guidance even during these curvature transitions. Finally, the overall control scheme is implemented, and improvements with respect to previous guidance laws are demonstrated through full-scale experiments.

Formation Control of Underactuated Surface Vessels using the Null-Space-Based Behavioral Control

Abstract: In this paper the application of a behavior-based control approach, namely the Null-Space-based Behavioral control, to coordinate a fleet of autonomous surface vessels is presented. The NSB can be considered as a centralized guidance system aimed at driving the fleet in complex environments while simultaneously performing multiple tasks, i.e., obstacle avoidance or keeping a formation. In order to apply the guidance system to a fleet of underactuated surface vessels, the NSB works in combination with a low-level maneuvering control that, taking care of the dynamics of the vessels, elaborates the motion commands to generate the generalized forces at the actuators. The guidance system has been simulated in the accomplishment of a mission in presence of obstacles and sea current in the environment.

A Compact Guidance, Navigation, and Control System for Unmanned Aerial Vehicles

Abstract: The Flight Control System 20 (FCS20) is a compact, self-contained Guidance, Navigation, and Control system that has recently been developed to enable advanced autonomous behavior in a wide range of Unmanned Aerial Vehicles (UAVs). The FCS20 uses a floating point Digital Signal Processor (DSP) for high level serial processing, a Field Programmable Gate Array (FPGA) for low level parallel processing, and GPS and Micro Electro Mechanical Systems (MEMS) sensors. In addition to guidance, navigation, and control functions, the FCS20 is capable of supporting advanced algorithms such as automated reasoning, artificial vision, and multi-vehicle interaction. The unique contribution of this paper is that it gives a complete overview of the FCS20 GN&C system, including computing, communications, and information aspects. Computing aspects of the FCS20 include details about the design process, hardware components, and board configurations, and specifications. Communications aspects of the FCS20 include descriptions of internal and external dataflow.The information section describes the FCS20 Operating System (OS), the Support Vehicle Interface Library (SVIL) software, the navigation Extended Kalman Filter, and the neural network based adaptive controller. Finally, simulation-based results as well as actual flight test results that demonstrate the operation of the guidance, navigation, and control algorithms on a real Unmanned Aerial Vehicle (UAV) are presented.

Formation Control of Marine Surface Vessels Using the Null-Space-Based Behavioral Control

Abstract: In this paper the application of the Null-Space-Based behavioral control (NSB) to a fleet of marine surface vessels is presented. From a marine applications point of view, the NSB can be considered as a guidance system that dynamically selects the motion reference commands for each vessel of the fleet. These motion commands are aimed at guiding the fleet in complex environments simultaneously performing multiple tasks, i.e., obstacle avoidance or keeping a formation. In order to apply the guidance system to a fleet of surface vessels through the entire speed envelope (fully-actuated at low velocities, under-actuated at high velocities), the NSB works in combination with a low-level maneuvering control that, taking care of the dynamic models of the vessels, elaborates the motion commands to obtain the generalized forces at the actuators. The guidance system has been simulated while successfully performing complex missions in realistic scenarios.

Vehicle Route Guidance Systems: Classification and Comparison

Abstract: Route guidance in vehicular roadways has become an important and emerging method of congestion alleviation. The proliferation of low cost electronics such as sensors, wireless communication, and computing equipment has now made large scale vehicle navigation practical. The advanced computational equipment available has made performing complex algorithms in real time possible, the key to the operation of vehicle route guidance systems. While route guidance systems fundamentally strive for similar optimum operation, several important differences exist in the design of these systems. This paper presents an investigation of some of the main distinctions between these systems. Much work has been done in this field in the past, which is presented here as a classification and comparison of such systems

Route guidance systems, methods, and programs

Abstract: Route guidance systems, methods, and programs detect a current position of a vehicle and search for a route to a destination on the basis of the vehicle position. The systems, methods, and programs set a guidance point at a predetermined distance before a target point on the searched route. If a guidance condition is met, the systems, methods, and programs provide route guidance about the target point when the vehicle reaches the guidance point, the guidance condition being met on the basis of the presence or absence of traffic lights at each of at least one intersection between the guidance point and the target point. If the guidance condition is met, the systems, methods, and programs output route guidance, the content of the route guidance being preset based on the guidance condition.

Autonomous and automatic landing system for drones

Abstract: The invention relates to an automatic aircraft landing guidance system having an electromagnetic detecting and locating device, positioned on the ground and a first multifunction transmitting/receiving radiofrequency beacon, on board each guided aircraft and transmitting in particular a continuous wave. The detecting and locating device uses the continuous wave transmitted by the beacon to perform a passive locating intended to improve the accuracy of the measurement of the angular position of the aircraft. It also comprises means for generating and periodically transmitting to the aircraft, via the beacon, information enabling said aircraft to rejoin an optimum landing path from its position. The invention applies more particularly to the guidance of autonomous and automatic aircraft such as drones in the approach and landing phase.

Precision Approach Guidance System And Associated Method

Abstract: A precision approach guidance system that provides flying craft guidance information during a precision approach to a landing site and methods associated therewith are provided. In one embodiment, the system includes: an inertial navigation system, an onboard ranging sensor, a terrain database storing previously identified position-referenced terrain information associated with the landing site, and a position determining process. The position determining process repetitively determines a corrected position of the flying craft during the precision approach based at least in part on attitude and velocity information from an inertial navigation system, current position-referenced terrain information based on measurements from an onboard ranging sensor, and previously identified position-referenced terrain information from the terrain database.

CoINS: Context Sensitive Indoor Navigation System

Abstract: The Context sensitive Indoor Navigation System (CoINS) implements an architecture to develop context-aware indoor user guidance services and applications. This paper presents a detailed discussion on algorithms and architectural issues in building an indoor guidance system. We first start with the World Model and required mapping to 2D for the process of path calculation and simplification. We also compare several algorithm optimizations applied in this particular context. The system provides the infrastructure to support different techniques of presenting the path and supporting user orientation to reach a certain destination in indoor premises.

How Reliable is this Route?: Predictive Travel Time and Reliability for Anticipatory Traveler Information Systems

Abstract: Schemes are addressed for providing predictive travel time information in consistent anticipatory route guidance systems. A user-equilibrium time-dependent traffic assignment algorithm with the ability for multiple-user class network loading is used to generate consistent anticipatory route guidance information when a fraction of the population is equipped to receive and act on that information. Both a theoretical analysis and a simulation-based approach are presented to evaluate the provision of anticipatory route guidance information in terms of experienced path travel times and their variations. Results indicate that the proposed anticipatory route guidance strategy is accurate and reliable and can improve real-time traffic network performance.

Differential-game-based guidance law using target orientation observations

Abstract: Modern 4th generation air-to-air missiles are quite capable of dealing with today's battlefield needs. Advanced aerodynamics, highly efficient warheads and smart target acquisition systems combine to yield higher missile lethality than ever. However, in order to intercept highly maneuverable targets, such as future unmanned combat air vehicles (UCAV), or to achieve higher tracking precision for missiles equipped with smaller warheads, further improvement in the missile guidance system is still needed. A new concept is presented here for deriving improved differential-game-based guidance laws that make use of information about the target orientation, which is acquired via an imaging seeker. The underlying idea is that of using measurements of the target attitude as a leading indicator of target acceleration. Knowledge of target attitude reduces the reachable set of target acceleration, facilitating the computation of an improved estimate of the zero-effort miss (ZEM) distance. In consequence, missile guidance accuracy is significantly improved. The new concept is applied in a horizontal interception scenario, where it is assumed that the target maneuver direction, constituting a partial attitude information, can be extracted via processing target images, acquired by an imaging sensor. The derivation results in a new guidance law that explicitly exploits the direction of the target acceleration. The performance of the new guidance law is studied via a computer simulation, which demonstrates its superiority over existing state-of-the-art differential-game-based guidance laws. It is demonstrated that a significant decrease in the miss distance can be expected via the use of partial target orientation information.

Guideway activated magnetic switching of vehicles

Abstract: A system for switching a transport vehicle comprising: a guideway, a vehicle (4) that moves along the guideway, and a magnetic field source that creates a force on the vehicle to affect motion in a desired direction at a switch. Once the vehicle (4) has started motion through the switch (7) the guidance can be continued by use of permanent magnets (2D, 2S) until the normal guidance system is effective. The switching scheme can work with any suspension scheme, including wheels and maglev, and can work with any lateral guidance scheme, including horizontal guide wheels and magnetic guidance. The system can be used with very closely spaced vehicles, such as with Personal Rapid Transit, material handling, and elevators with multiple cabs in the same shaft.

An Optical System for Guidance of Terrain Following in UAVs

Abstract: There is considerable interest in designing guidance systems for UAVs that use passive sensing (such as vision), rather than active sensing which can be bulky, expensive and stealth-compromising. Here we describe an optical sensor, based partly on principles of insect vision and optic flow analysis, for measurement and control of height above the ground. A video camera is used in conjunction with a specially shaped reflective surface to simplify the computation of optic flow, and extend the range of aircraft speeds over which accurate data can be obtained. The imaging system also provides a useful geometrical remapping of the environment, which facilitates obstacle avoidance and computation of 3-D terrain maps.

Linear Programming and Language Processing for Human-Unmanned Aerial-Vehicle Team Missions

Abstract: This paper presents a manned-vehicle/unmanned-aerial-vehicle (UAV) mission system that enables an operator in a manned aircraft to issue mission level commands to an autonomous aircraft in real time. A natural language interface allows the manned and unmanned vehicle to communicate in languages understood by both agents. A task scheduler transforms the commands into a dynamic mission plan consisting of task waypoints. These are then given to a mixed-integer linear programming (MILP)-based trajectory optimizer, which safely guides the vehicle through a partially known environment in real time. The MILP trajectory planning formulation and its implementation are discussed in detail. Integrated simulation and June 2004 flight-test results that used an F-15 and an autonomous T-33 equipped with Boeing’s unmanned combat air vehicle (UCAV) avionics package are presented. These activities were part of the Capstone Demonstration of the Defense Advanced Research Projects Agency-sponsored Software Enabled Control effort. The flight tests mark the first time that an onboard MILPbased guidance system was used to control a UAV. They also mark the first time that a natural language interface was used by a manned vehicle to task a UAV in real time.

A Remote Vision Guidance System for Visually Impaired Pedestrians

Abstract: This paper presents research and development work on a novel system with a view of developing a navigation system for the guidance of visually impaired pedestrians. The prime aim of the new developed system is to enhance the mobility of visually impaired pedestrians using remote guidance provided by sighted person. However, the system can be used in many other applications. The system implementation is based on the integration of the Global Positioning System (GPS), Geographical Information System (GIS) database and a remote vision facility over the third generation (3G) of mobile networks, providing a technological platform enabling visually impaired pedestrians to be guided remotely by a sighted guide.

A High G, MEMS Based, Deeply Integrated, INS/GPS, Guidance, Navigation and Control Flight Management Unit

Abstract: Integrated Guidance Systems LLC (IGS LLC), a joint venture between Honeywell and Rockwell Collins, has developed the next generation, Deeply Integrated (DI) guidance, navigation and control product which will meet the emerging demands of military applications. The guidance, navigation and control Flight Management Unit (FMU) is based on Selective Availability Anti-Spoof Module (SAASM) and Micro Electromechanical System (MEMS) sensor technology and is housed in a small, light weight, low power package. In addition to meeting the demands of the military’s gun-hardened guided projectile and missile applications, the FMU has applicability in soldier personal navigation systems and military/commercial attitude, heading and reference systems (AHRS). When coupled with Honeywell’s second generation C++ based Embedded Computer Toolbox and Operating System (ECTOS™ IIc), the FMU can be utilized easily and effectively for rapid prototyping demonstration (including customer generated guidance and control software), as well as full production systems. Utilizing the latest processor technology, the FMU has been designed to accommodate the next generation INS/GPS Ultra Tightly Coupled (UTC) algorithms. The UTC algorithms, together with the embedded hardware anti-jam electronics, enables the FMU to perform in the otherwise potentially disabling environment of today’s battlefield. The FMU has been tested to 20,000 G’s (battery backed state), successfully demonstrating the hardware components survive and perform after exposure to the high G environment. This paper presents an overview of the FMU and ECTOS™ IIc software. The hardware architecture and technical specifications of the FMU will be presented, along with a more detailed look at its high G and anti-jam capability. Performance will be reviewed as well as the IGS LLC’s approach to providing a deterministic IEEE 1394b bus protocol. Finally, the software architecture, capability, and customer usability / programmability features of ECTOS™ IIc will be described.

Endgame Guidance and Relative Navigation of Strategic Interceptors with Delays

Abstract: This paper is concerned with endgame guidance and relative navigation of strategic missiles equipped with divert thrusters to intercept nonmaneuvering reentry vehicles. The paper has three objectives: 1) demonstrate superiority of predictive guidance to pulsed proportional navigation guidance; 2) devise compensation for a onesample delay in arrival of line-of-sight (LOS) angle measurements at Kalman-filter module and another one-sample delay in communication of LOS rate estimates to the guidance module; and 3) develop a Kalman filter insensitive to modeling errors for relative navigation. A hybrid Kalman filter is developed for relative navigation with angle measurements—hybrid because relative position and velocity vectors are propagated in Cartesian coordinates, whereas the error covariance is propagated, and updated at the time of measurement, in spherical coordinates. For spherical computations, a time-to-go dependent transition matrix and a time-to-go dependent process noise matrix are formulated. It is shown that these time-to-go dependent matrices reduce the miss distance and its sensitivity to modeling errors. With this Kalman filter, it is shown that the closed-loop predictive guidance yields smaller miss distance, consumes less fuel, and requires fewer divert firings than the pulsed proportional navigation guidance does. The delay compensation is accomplished in two steps: first, the high-frequency stream of ∆V measurements from an accelerometer is stored and synchronized with the delayed LOS angle measurement from the seeker; second, the delayed LOS rate estimate from the Kalman filter is propagated forward using the measured ∆V that transpires during the delay. The miss distance of the zero-delay level and robustness to modeling errors is shown to be almost recovered.

LIDAR Sensing for Vehicle Lateral Guidance: Algorithm and Experimental Study

Abstract: This paper describes a new vehicle detection system based on a laser imaging, detection, and ranging (LIDAR) sensor, and conducts an experimental study to investigate the sensor's role in the current California PATH vehicle lateral guidance systems. The LIDAR sensor is installed on a controlled vehicle and it can measure the relative distance of the vehicle from a preceding vehicle, by scanning the horizontal plane with laser beams. Environmental clutter becomes the main challenge in data processing, when LIDAR tries to track the desired target. A probabilistic data association-based algorithm has been developed to solve this problem, which has been verified in real-time experiments using two Buick LaSabre vehicles. The experimental study also reveals the relation between the LIDAR outputs and the magnetic reference system widely used by the current PATH lateral control systems, and the results provide the guidelines on how this new sensor system may be used for vehicle lateral guidance

Decision-Directed Adaptive Estimation and Guidance for an Interception Endgame

Abstract: A new integrated estimation and guidance design approach is presented as a computationally effective procedure for interception of maneuvering targets. This is an adaptive approach that uses the following elements: banks of state estimators, and guidance laws, a maneuver detector for the onset of the target’s maneuver, and a hierarchical decision law for online selection of the estimator/guidance law pair to be employed. Simulation results confirm that the adaptive approach leads to a reduction in the miss distance as compared with cases in which only a single estimator/guidance law combination is available. LTHOUGH the study presented in this paper was motivated by a future ballistic missile defense (BMD) scenario, it addresses a more general problem, namely, the interception of a randomly maneuvering target by a guided missile in an environment of noise-corrupted measurements. The missile guidance endgame is an imperfect information terminal control problem with a very short horizon and it requires a design approach different from the one used in other control systems. In the classical approach, a linearized model of the dynamic process about a nominal set point is first derived. For this linearized model, the estimator and the control law are designed independently. The separate design is based on assuming the validity of the certainty equivalence principle (CEP) and the associated separation theorem (ST). 1

Machine Vision Guidance System for a Modular Climbing Robot used in Shipbuilding

Abstract: During naval construction, vessels are divided into various blocks or subunits that are manufactured in different workshops and then carried to a building dock or shipway where they are welded together. This paper describes a versatile lightweight climbing robot that is capable of moving on the hull and a compact machine vision guidance system that allows it to follow grooves on the surface of the hull. This capability is useful for tasks such as inspecting welding seams, reducing the need for scaffolds. The robot is designed as a three wheeled Synchro-Drive vehicle. That allows it to perform movements in any direction without changing its orientation. The force of attraction necessary to stick the robot to the ship’s hull is provided by three permanent magnets that are placed at the bottom of the robot. To guide this robot when it operates in automatic mode, a real time machine vision system has been developed. This system is prepared to detect and track the groove that is formed between two blocks of a ship when they are joined for welding. This groove is detected by the vision system using a multiline laser beam and a camera with an appropriate filter. The camera used for this application is a compact vision system that includes image capturing, image processing and communications capacities in a single unit.

Route guidance system, methods and programs

Abstract: Route guidance systems, methods and programs detect a current position of a host vehicle and search for a specified route to a destination based on the current position of the vehicle The systems, methods and programs set a guidance intersection based on a specified route, and compute a recommended lane on each road along the specified route The systems, methods and programs detect a recommended lane change point where a recommended lane changes between the current position of the vehicle and the guidance intersection The systems, methods and programs notify the driver that the recommended lane will change before the host vehicle arrives at the recommended lane change point

Iterative solution to differential geometric guidance problem

Abstract: Purpose – To study the application of three‐dimensional differential geometric (DG) guidance commands to a realistic missile defense engagement, and the application of the Newton's iterative algorithm to DG guidance problems.Design/methodology/approach – The classical differential geometry theory is introduced firstly to transform all the variables in DG guidance commands from an arc length system to the time domain. Then, an algorithm for the angle‐of‐attack and the sideslip angle is developed by assuming the guidance curvature command and guidance torsion command equal to its corresponding value of current trajectory. Furthermore, Newton's iteration is utilized to develop iterative solution of the stated algorithm and the two‐dimensional DG guidance system so as to facilitate easy computation of the angle‐of‐attack and the sideslip angle, which are formulated to satisfy the DG guidance law.Findings – DG guidance law is viable and effective in the realistic missile defense engagement, and it is shown to ...

Generating Optimal Controlled Prescriptive Route Guidance in Realistic Traffic Networks; A Generic Approach

Abstract: A generic methodology to generate optimal controlled dynamic prescriptive route guidance to be disseminated by means of variable message signs (VMSs) is presented. The methodology is generic in the sense that it can be used on any network topology and network model, with any number of VMSs, for different traffic scenarios (e.g., recurrent congestion, accidents, or special events); is based on a flexible, user-defined objective function; and will work as long as feasible route alternatives exist. The presented methodology calculates prescriptive VMS settings with the objective of minimizing the total generalized travel time. An evolutionary algorithm is used to generate and optimize VMS scenarios. A new traffic model, DSMART, has been developed to assess the quality of the route guidance. A prototype of the guidance system has been developed in Matlab and applied in a case study of Rotterdam, Netherlands, by using a network representation of the motorway with six different VMSs and the connected urban netw...

Trajectory Guidance and Control for a Small UAV

Abstract: The objective of this paper is to present trajectory guidance and control system with a dynamic inversion for a small unmanned aerial vehicle (UAV). The UAV model is expressed by fixed-mass rigid-body six-degree-of-freedom equations of motion, which include the detailed aerodynamic coefficients, the engine model and the actuator models that have lags and limits. A trajectory is generated from the given waypoints using cubic spline functions of a flight distance. The commanded values of an angle of attack, a sideslip angle, a bank angle and a thrust, are calculated from guidance forces to trace the flight trajectory. To adapt various waypoint locations, a proportional navigation is combined with the guidance system. By the decision logic, appropriate guidance law is selected. The flight control system to achieve the commands is designed using a dynamic inversion approach. For a dynamic inversion controller we use the two-timescale assumption that separates the fast dynamics, involving the angular rates of the aircraft, from the slow dynamics, which include angle of attack, sideslip angle, and bank angle. Some numerical simulations are conducted to see the performance of the proposed guidance and control system.

Inertial navigational guidance system for a driverless vehicle utilizing laser obstacle sensors

Abstract: A navigational control system for, and method of controlling the operation of, a driverless vehicle. The system includes a vehicle travel path and a visual object detection system for generating data relating to the position of the vehicle relative to objects in readable proximity to the travel path. The system includes an inertial guidance system for controlling operation of steering and drive mechanisms to direct the vehicle substantially along the travel path, and for correcting deviation from said travel path based upon data generated by said visual object detection systems, and for detecting impending obstacle contact.

Route guidance system

Abstract: PROBLEM TO BE SOLVED: To provide a route guidance system capable of intelligibly executing route guidance even for a person who is poor at understanding a map. SOLUTION: The route guidance system 100 includes a communication robot 10 and a display device 12. For example, when the person A existing near the display device 12 is detected based on a detection result of a floor sensor 18, the robot 10 asks the person whether or not the route guidance is required. If the route guidance is required, the robot 10 further asks the person the destination. When destination information is acquired from the robot 10, a computer 14 sequentially displays a path from the present location to the destination by every key point (path point) on the display device 12. In addition, the computer 14 properly transmits control commands to the robot 10 and transmits (explains) the direction in which the person should go by utterance and gestures by every key point. As a result, since the path from the present position to the destination is displayed and the path on which the person should go is explained to the person by the gestures, the path to the destination is intelligibly explained without transfer of the robot to the destination with the person. COPYRIGHT: (C)2008,JPO&INPIT