Showing papers on "Guidance system published in 2012"

NAVIG: augmented reality guidance system for the visually impaired

Abstract: Navigating complex routes and finding objects of interest are challenging tasks for the visually impaired The project NAVIG (Navigation Assisted by artificial VIsion and GNSS) is directed toward increasing personal autonomy via a virtual augmented reality system The system integrates an adapted geographic information system with different classes of objects useful for improving route selection and guidance The database also includes models of important geolocated objects that may be detected by real-time embedded vision algorithms Object localization (relative to the user) may serve both global positioning and sensorimotor actions such as heading, grasping, or piloting The user is guided to his desired destination through spatialized semantic audio rendering, always maintained in the head-centered reference frame This paper presents the overall project design and architecture of the NAVIG system In addition, details of a new type of detection and localization device are presented This approach combines a bio-inspired vision system that can recognize and locate objects very quickly and a 3D sound rendering system that is able to perceptually position a sound at the location of the recognized object This system was developed in relation to guidance directives developed through participative design with potential users and educators for the visually impaired

Impact-Angle-Constrained Suboptimal Model Predictive Static Programming Guidance of Air-to-Ground Missiles

Abstract: A nonlinear suboptimal guidance law is presented in this paper for successful interception of ground targets by air-launched missiles and guided munitions. The main feature of this guidance law is that it accurately satisfies terminal impact angle constraints in both azimuth as well as elevation simultaneously. In addition, it is capable of hitting the target with high accuracy as well as minimizing the lateral acceleration demand. The guidance law is synthesized using recently developed model predictive static programming (MPSP). Performance of the proposed MPSP guidance is demonstrated using three-dimensional (3-D) nonlinear engagement dynamics by considering stationary, moving, and maneuvering targets. Effectiveness of the proposed guidance has also been verified by considering first. order autopilot lag as well as assuming inaccurate information about target maneuvers. Multiple munitions engagement results are presented as well. Moreover, comparison studies with respect to an augmented proportional navigation guidance (which does not impose impact angle constraints) as well as an explicit linear optimal guidance (which imposes the same impact angle constraints in 3-D) lead to the conclusion that the proposed MPSP guidance is superior to both. A large number of randomized simulation studies show that it also has a larger capture region.

System for indoor guidance with mobility assistance

Abstract: An indoor guidance system for a blind or visually impaired person. The system uses a mobile device (Smartphone, tablet, etc.) to provide maps and visual and voice guidance to assist individuals in navigating through indoor locations. Special maps are transmitted to the mobile device upon entering the facility, or downloaded in advance. The software and maps provide assistance to the user, to guide them through the facility. The system uses a combination of GPS and other technologies (Bluetooth, infrared, Wi-Fi, RFID, etc.) to provide extremely detailed and accurate location information to the user.

A Comparison of Control Techniques for Robust Docking Maneuvers of an AGV

Abstract: This work addresses the path tracking problem of industrial guidance systems used by automated guided vehicles (AGVs) in load transfer operations. We focus on the control law that permits to AGVs to operate tracking a predefined route with industrial grade of accuracy, repeatability and reliability. One of the main issues of this problem is related to the important weight variation of AGVs when transporting a load, which induces slipping and skidding effects. Besides, localization error of the guidance system should be taken into account because position estimation is typically performed at a low sample rate. Other key point is that control law oscillations can knock down the load, which gives rise to safety and performance problems. Three control techniques - fuzzy, vector pursuit and flatness-based control - are compared in order to evaluate how they can deal with these problems and satisfy the robustness requirements of such an industrial application.

Retro-Proportional-Navigation: A New Guidance Law for Interception of High-Speed Targets

Abstract: In this paper, a new proportional-navigation guidance law, called retro-proportional-navigation, is proposed. The guidance law is designed to intercept targets that are of higher speeds than the interceptor. This is a typical scenario in a ballistic target interception. The capture region analysis for both proportional-navigation and retro-proportional-navigation guidance laws are presented. The study shows that, at the cost of a higher intercept time, the retro-proportional-navigation guidance law demands lower terminal lateral acceleration than proportional navigation and can intercept high-velocity targets from many initial conditions that the classical proportional navigation cannot. Also, the capture region with the retro-proportional-navigation guidance law is shown to be larger compared with the classical proportional-navigation guidance law.

Effects of different factors on drivers’ guidance compliance behaviors under road condition information shown on VMS

Abstract: It is generally accepted that compliance behavior is affected by many factors. The purpose of this study is to investigate the effects of diverse factors on drivers' guidance compliance behaviors under road condition information shown on graphic variable message sign (VMS), and based on this to find out a better information release mode. The involved data were obtained from questionnaire survey, and ordinal regression was used to analyze the casual relation between guidance compliance behavior and its influencing factors. Based on an overall analysis of conditions in driver's route choice, an accurate method was proposed to calculate the compliance rate. The model testing information indicated that ordinal regression model with complementary log-log being the link function was appropriate to quantify the relation between the compliance rate and the factors. The estimation results showed that age, driving years, average annual mileage, monthly income, driving style, occupation, the degree of trust in VMS, the familiarity with road network and the route choice style were significant determinants of guidance compliance behavior. This paper also compared two different guidance modes which were ordinary guidance mode (M1) and predicted guidance mode (M2) through simulation. The average speed fluctuations and average travel time supported that M2 had better effect in improving traffic flow and balancing traffic load and resource. Some detailed suggestions of releasing guidance information were proposed with the explanation by flow-density curve and variation of traffic flows. These findings are the foundation to design and improve guidance systems by assessing guidance effect and modifying guidance algorithm.

Navigation of automated guided vehicles using magnet spot guidance method

Abstract: Automated guided vehicle systems (AGVSs) are used to transport goods and products in most manufacturing systems. In this research, we use a cylindrical magnet spot, which is widely used in industrial AGVSs, to develop a guidance system for indoor AGV navigation. This paper describes the navigation and control system of an AGV by magnet spot guidance with a differential drive. Furthermore, Hall-effect sensors, encoders, and counters are employed to achieve control and continuous guidance. Existing guidance methods use a gyro sensor and dead reckoning with encoders to calibrate against steering angle errors. Here, the maximum value of the magnetic flux density of the magnet spot, which is obtained by the Hall-effect sensor, is used to calibrate against steering angle errors and as a navigation guide for the AGV. Furthermore, real-time corrections for wheel-skidding errors are accomplished with a fuzzy controller. Thus, high-precision continuous guidance with stable and satisfactory navigation at high speeds is achieved. This guidance method was applied to real manufacturing processes in a ceramic plant and steel-bar reinforcement plant to examine its control ability, stability, and effectiveness. The proposed method was found to be robust to disturbances and uncertainty problems during tracking.

Multimodal motion guidance: techniques for adaptive and dynamic feedback

Abstract: The ability to guide human motion through automatically generated feedback has significant potential for applications in areas, such as motor learning, human-computer interaction, telepresence, and augmented reality.This paper focuses on the design and development of such systems from a human cognition and perception perspective. We analyze the dimensions of the design space for motion guidance systems, spanned by technologies and human information processing, and identify opportunities for new feedback techniques.We present a novel motion guidance system, that was implemented based on these insights to enable feedback for position, direction and continuous velocities. It uses motion capture to track a user in space and guides using visual, vibrotactile and pneumatic actuation. Our system also introduces motion retargeting through time warping, motion dynamics and prediction, to allow more flexibility and adaptability to user performance.

Electric taxi system guidance

Abstract: A taxi guidance system is provided for an aircraft having a primary thrust engine and an onboard electric taxi system. The taxi guidance system includes or cooperates with a source of aircraft status data for the aircraft, and a source of airport feature data associated with synthetic graphical representations of an airport field. The taxi guidance system includes a processor operatively coupled to the source of aircraft status data and to the source of airport feature data to generate, in response to at least the aircraft status data and the airport feature data, taxi path guidance information for the aircraft, start/stop guidance information associated with operation of the primary thrust engine, and speed guidance information for the onboard electric taxi system. The processor generates image rendering display commands that can be received by a display system (400) to render a dynamic synthetic representation of the airport field that includes graphical indicia of the taxi path guidance information (410), the start/stop guidance information (414), and the speed guidance information (420) .

Communication technique by which an autonomous guidance system controls an industrial vehicle

Abstract: A propulsion drive system is operated by a controller to propel an industrial vehicle along a path in an unmanned mode. An autonomous processor module sends commands to the vehicle controller in response to messages received via a communication network from a guidance and navigation system. The guidance and navigation system transmits a message over the communication network, wherein that message contains a first numerical value specifying the velocity and a second numerical value specifying an amount that the propulsion drive system is to turn a wheel of the industrial vehicle. The message also specifies a maximum speed limit and indicators commanding that a load carried by the industrial vehicle be raised and lowered. The autonomous processor module transmits a feedback message indicate actual vehicle operating parameters to the guidance and navigation system.

Robust Landing Guidance Law for Impaired Aircraft

Abstract: A guidance law for landing an impaired aircraft is described. The approach involves a planning phase wherein the performance limits of the aircraft are used to design the landing pattern and the reference speed, followed by the guidance computations for generating attitude commands. Commanded attitude can be displayed the pilot on a heads-up display for manual control, or can be coupled to the autopilot. In addition to the attitude commands, the guidance system can also generate the flap deployment schedules, and auto-brake system initiation trigger in equipped aircraft. Guidance system development is based on a pointmass nonlinear model of the aircraft. Feedback linearization technique is used to transform the system dynamics into a linear, time-invariant form. Finite interval differential game formulation is then used to derive the robust optimal guidance law. Inverse transformation of the guidance commands to the original coordinate system produces the roll, pitch and yaw attitude commands. Attitude commands can be tailored for both the crabbed or sideslip flight modes, and for the transitions between them. Simulation results are given to demonstrate the performance of the proposed approach.

Carrier-phase GNSS attitude determination and control system for unmanned aerial vehicle applications

Abstract: This paper presents the results of a research activity performed by Cranfield University to assess the potential of carrierphase Global Navigation Satellite Systems (GNSS) for attitude determination and control of small to medium size Unmanned Aerial Vehicles (UAV). Both deterministic and recursive (optimal estimation) algorithms are developed for combining multiple attitude measurements obtained from different observation points (i.e., antenna locations), and their efficiencies are tested in various dynamic conditions. The proposed algorithms converge rapidly and produce the required output even during high dynamics manoeuvres. Results of theoretical performance analysis and simulation activities are presented in this paper, with emphasis on the advantages of the GNSS interferometric approach in UAV applications (i.e., low cost, high data-rate, low volume/weight, low signal processing requirements, etc.). Modelling and simulation activities focussed on the AEROSONDE UAV platform and considered the possible augmentation provided by interferometric GNSS techniques to a low-cost and low-weight/volume integrated navigation system recently developed at Cranfield University, which employs a Vision-based Navigation (VBN) system, a Micro-Electro-mechanical Sensor (MEMS) based Inertial Measurement Unit (IMU) and code-range GNSS (i.e., GPS and GALILEO) for position and velocity computations. The integrated VBN-IMU-GNSS (VIG) system is augmented by using the inteferometric GNSS Attitude Determination (GAD) and a comparison of the performance achievable with the VIG and VIG/GAD integrated Navigation and Guidance Systems (NGS) is presented. Finally, the data provided by these NGS are used to optimise the design of an hybrid controller employing Fuzzy Logic and Proportional-Integral-Derivative (PID) techniques for the AEROSONDE UAV.

High integrity, surface guidance system for aircraft electric taxi

Abstract: A high-integrity auto-guidance and control method for use in conjunction with an aircraft electric taxi drive system comprises obtaining taxi path data generating in a plurality of processors taxi path guidance and control information from the taxi path guidance data, and sending commands derived from the taxi path guidance and control information from one of the plurality of processors based on a predetermined priority scheme to at least one electric taxi controller.

Adaptive-sliding-mode guidance law design for missiles with thrust vector control and divert control system

Abstract: This approach addresses an adaptive-sliding-mode guidance law for missiles equipped with thrust vector control and divert control system, for the task of intercepting of a theatre ballistic missile with manoeuvring acceleration. The aim of the present study is to achieve a bounded target interception under the three degrees of freedom (DOF) control and the zero-effort-miss phase to improve the intercepting accuracy of the missile by narrowing the distance between the intercepting missile and the target missile to within effective range for triggering the missile’s explosion. Considering the external disturbances and the variation in the missile’s mass, the 3 DOF adaptive-sliding-mode guidance law is designed using adaptive control and sliding-mode control to minimise the distance between the centre of the intercepting missile and that of the target missile asymptotically. Also, the overall system stability is verified using the Lyapunov stability theory. Furthermore, successful simulation results are conducted to validate the effectiveness of the proposed adaptive-sliding-mode guidance law.

Developments in the field of automatic guidance and control of rockets

Abstract: Introduction T definitions are that "navigation" determines the vehicle's state for initial conditions as well as during flight; that "guidance" selects the maneuvering sequence to get from the instantaneous state to a required state; and that "control" executes the maneuvers called for by guidance. These definitions did not exist in the early development years. Navigation corrections were usually taken care of by flight time deviations, which were included in simple guidance functions. Fixed programs, such as flight-tilt programs and roll programs, to rotate the vehicle into its required flight plane have been considered control functions rather than guidance functions and have been exceptions to these definitions. The development of liquid fuel and oxidizer engines made it necessary to stabilize the rockets and to provide attitude control. This included a pitch tilt program, because these rockets with their low initial acceleration had to be launched in a vertical direction. In order to aim at a target the next requirements were to constrain the rocket to a predetermined flight plane and to provide a well-defined velocity vector at propulsion cutoff of the rocket engine. Related but less sophisticated requirements had existed for ship and airplane control. Inertial sensors, such as gimbal suspended gyroscopes and rate gyros, had been used for these systems. In 1912 Prof. Max Schuler had designed a threegyro, three-degree-of-freedom gyro compass for ship navigation, and two-degree-of-freedom gyros were used later as airplane orientation sensors. Schemes and components derived from these systems were applied to the first rocket attitude control systems. A somewhat more difficult task was to obtain guidance sensors, which did not exist yet. For many years inertial sensors were in competition with radio guidance devices, the latter being more promising in the early years to fulfill accuracy requirements. Accelerometers had to be used as inertial sensors for guidance. Velocity and displacement, as the information required, had to be derived; the first with normalized accuracy demands of at least 10~-10~ . The derived signals had to be obtained by the only available method, which was mechanical integration. In contrast to the inertial sensors, the radio sensors measured lateral displacements and forward (radial) velocities directly. Since the guidance systems had to be used for missiles an inertial system was preferable because it is self-contained and not subjected to external interference as radio guidance systems are. The radio guidance system became available and operational first. It yielded an accuracy in range that was about 10% better than the inertial system introduced afterward. Only a few test flights with a pure inertial system took place before the end of World War II. The cross-range impact errors were approximately twice as large as with the radio guidance system. Thus for some time it

Travel guidance system, travel guidance apparatus, travel guidance method, and computer program

Abstract: A guidance prompt used for guidance for a guide branch point ahead of a movable object is selected from among a plurality of potential guidance prompts, based on whether a distance from a guidance starting point where guidance starts to a guidance ending point by which guidance is required to be finished is greater than a distance traveled by the movable object while guidance is being spoken. The selected guidance prompt is then set as the guidance prompt for the guide branch point, and guidance for the guide branch point by the set guidance prompt is performed when the movable object reaches the guidance starting point associated with the set guidance prompt.

System and method for needle deployment detection in image-guided biopsy

Abstract: A system and method for medical device detection includes a guidance system (38) configured to deliver a surgical device (32) into a subject A surgical device deployment detector (25, 40, 42, 44) is configured to cooperate with the guidance system and is configured to detect a deployment of the surgical device in the subject A coordination module (22)is configured to receive input from the guidance system and the deployment detector to determine and record one or more of a location and time of each deployment

Partial stabilization-based guidance.

Abstract: A novel nonlinear missile guidance law against maneuvering targets is designed based on the principles of partial stability. It is demonstrated that in a real approach which is adopted with actual situations, each state of the guidance system must have a special behavior and asymptotic stability or exponential stability of all states is not realistic. Thus, a new guidance law is developed based on the partial stability theorem in such a way that the behaviors of states in the closed-loop system are in conformity with a real guidance scenario that leads to collision. The performance of the proposed guidance law in terms of interception time and control effort is compared with the sliding mode guidance law by means of numerical simulations.

Frequency-Modulated Pulse-Jet Control of an Artillery Rocket

Abstract: Longandmedium-range artillery rockets are used for indirect fire on distant targets. As they have a large impactpoint dispersion, they are considered tobe areaweapons.Nevertheless, a control system is required in order to reduce the dispersion and increase hit probability. The pulse-jet control system is simple and efficient enough to produce acceptable impact-point dispersion. However, it is necessary to perform an optimization of the control logic in order to obtain a satisfactory performance with the minimum number and intensity of control pulses. A new two-phase guidance scheme named trajectory tracking with pulse-frequencymodulation is presented, considering the fact that an artillery rocket flies through different atmospheric environments. Simulation studies have been conducted in order to perform parametric and performance analyses. It is shown that the presented guidance scheme achieves excellent accuracy even in the case of a small number of pulse jets. In the case of a large number, it tends to nullify the impact-point dispersion. It is also shown that in comparison with the window-based trajectory-tracking guidance, the proposed method achieves significantly better results.

Aircraft Trajectory Tracking by Nonlinear Spatial Inversion

Abstract: With the growth of civil aviation traffic, enhanced accuracy performances are required from guidance systems to maintain efficiency and safety in flight operations. This communication proposes a new representation of aircraft flight dynamics at approach for landing and a space-based nonlinear dynamic inversion control technique for the guidance of transportation aircraft. The main novelty is that the adopted independent variable is distance to land which allows the development of a new guidance approach with a perspective for improved performance.

A guaranteed obstacle avoidance guidance system

Abstract: This paper presents a practical solution to the guidance of a unicycle type robot, including path following, obstacle avoidance and the respect of wheeled actuation saturation constraint, without planning procedure. These results are based on an extension of previous results on path following control including actuation saturation constraints. New solution for obstacle avoidance, with guaranteed performance, is proposed.

Networked control system for the guidance of a four-wheel steering agricultural robotic platform

Abstract: A current trend in the agricultural area is the development of mobile robots and autonomous vehicles for precision agriculture (PA). One of the major challenges in the design of these robots is the development of the electronic architecture for the control of the devices. In a joint project among research institutions and a private company in Brazil a multifunctional robotic platform for information acquisition in PA is being designed. This platformhas asmain characteristics four-wheel propulsion and independent steering, adjustable width, span of 1,80m in height, diesel engine, hydraulic system, and a CAN-based networked control system (NCS). This paper presents a NCS solution for the platform guidance by the four-wheel hydraulic steering distributed control. The control strategy, centered on the robot manipulators control theory, is based on the difference between the desired and actual position and considering the angular speed of the wheels. The results demonstrate that the NCS was simple and efficient, providing suitable steering performance for the platform guidance. Even though the simplicity of the NCS solution developed, it also overcame some verified control challenges in the robot guidance system design such as the hydraulic system delay, nonlinearities in the steering actuators, and inertia in the steering system due the friction of different terrains.

Mars Science Laboratory Navigation Results

Abstract: The Mars Science Laboratory (MSL), carrying the Curiosity rover to Mars, was launched on November 26, 2011, from Cape Canaveral, Florida. The target for MSL was selected to be Gale Crater, near the equator of Mars, with an arrival date in early August 2012. The two main interplanetary navigation tasks for the mission were to deliver the spacecraft to an entry interface point that would allow the rover to safely reach the landing area, and to tell the spacecraft where it entered the atmosphere of Mars, so it could guide itself accurately to close proximity of the landing target. MSL used entry guidance as it slowed down from the entry speed to a speed low enough to allow for a successful parachute deployment, and this guidance allowed shrinking the landing ellipse to a 99% conservative estimate of 7 by 20 kilometers. Since there is no global positioning system in Mars, achieving this accuracy was predicated on flying a trajectory that closely matched the reference trajectory used to design the guidance algorithm, and on initializing the guidance system with an accurate Mars-relative entry state that could be used as the starting point to integrate the inertial measurement unit data during entry and descent. The pre-launch entry flight path angle (EFPA) delivery requirement was +/- 0.20 deg, but after launch a smaller threshold of +/- 0.05 deg was used as the criteria for late trajectory correction maneuver (TCM) decisions. The pre-launch requirement for entry state knowledge was 2.8 kilometers in position error and 2 meters per second in velocity error, but also smaller thresholds were defined after launch to evaluate entry state update opportunities. The biggest challenge for the navigation team was to accurately predict the trajectory of the spacecraft, so the estimates of the entry conditions could be stable, and late trajectory correction maneuvers or entry parameter updates could be waved off. As a matter of fact, the prediction accuracy was such that the last TCM performed was a small burn executed eight days before landing, and the entry state that was calculated just 36 hours after that TCM, and that was uploaded to the spacecraft the same day, did not need to be updated. The final EFPA was 0.013 deg shallower than the -15.5 deg target, and the on-board entry state was just 200 meters in position and 0.11 meters per second in velocity from the post-landing reconstructed entry state. Overall the entry delivery and knowledge requirements were fulfilled with a margin of more than 90% with respect to the pre-launch thresholds. This excellent accuracy contributed to a very successful and accurate entry, descent, and landing, and surface mission.

Optimal Path Planning for Unmanned Aerial Systems

Abstract: This thesis is a contribution to the Unmanned Aerial Vehicle (UAV) project at the Department of Engineering Cybernetics, which is a project where contributions from master students and Phd students will result in an autonomous aerial vehicle. The unmanned vehicle laboratory has its own UAV, the Odin Recce D6 delta-wing aircraft which is to be considered in the overall project. When the UAV is in the air on a mission, one important thing is to ensure that the UAV detects obstacles, such as mountains, buildings and other aircrafts. No-fly areas should be avoided by the path planner. This thesis considers a guidance system that will set up a path from the initial position to the final destination, and make sure that the generated trajectory is safe. One problem with the design of the optimal path has been that the designed path gives textit{corner cutting} when obstacles from the environment is included in the path-planner. To avoid this problem, which happens because discrete time is considered, two different solutions to avoid this problem have been discussed closer. Implementation of constraints and different cost functions for path planning with collision avoidance using the Mixed Integer Linear Programming (MILP) is one of the purposes of this thesis. The MILP algorithm is developed for the case of planar motion where the UAV has to fly around the obstacle, and can't fly over or under it. The design of the path path planner using MILP is done in two different ways. One where obstacles are known at the beginning of the optimization, and one where obstacles are added as information to the path planner when they are in the range of the UAVs radar. It is shown that the implementation with obstacle radar detection is more realistic, and that it also improves the computation time. As the author knows this method has not been published in articles up to this date. Two different approaches for search of a defined area with an arbitrary number of UAVs with camera systems have been developed and implemented through this thesis. As far as the author of this thesis knows these approaches for search have not been published up to this date. Efficient search and low computational complexity has been important design factors during the development of these approaches. The final systems are simulated in MATLAB for some test-scenarios. Also, reflection and discussion on further improvement on the path planning system are included in the report. This includes further improvement of the guidance system using receding horizon strategies. A literature study on path planning with receding horizon has been done.

A Novel Approach for Trajectory Tracking of UAVs

Abstract: Purpose – The purpose of this paper is to present a novel approach for trajectory tracking of UAVS. Research on unmanned aircraft is constantly improving the autonomous flight capabilities of these vehicles to provide performance needed to use them in even more complex tasks. The UAV path planner (PP) plans the best path to perform the mission. This is a waypoint sequence that is uploaded on the flight management system providing reference to the aircraft guidance, navigation and control system (GNCS). The UAV GNCS converts the waypoint sequence in guidance references for the flight control system (FCS) that, in turn, generates the command sequence needed to track the optimum path. Design/methodology/approach – A new guidance system (GS) is presented in this paper, based on the graph search algorithm kinematic A* (KA*). The GS is linked to a nonlinear model predictive control (NMPC) system that tracks the reference path, solving online (i.e. at each sampling time) a finite horizon (state horizon) open loo...

View-point guided weapon system and target designation method

Abstract: A passive guidance system including a viewpoint capture system (VCS) including a first processor in communication with first memory and a first SWIR imager for creating a viewpoint image database having a plurality of images, at least one of the images having a target point. A weapon guidance module is in communication with the VCS and coupled to a weapon. The weapon guidance module includes a second processor in communication with second memory and a second SWIR imager for storing the viewpoint image database and correlating in-flight images from the second SWIR imager to provide guidance commands directing the weapon to the target point.