Showing papers on "Guidance system published in 2018"
TL;DR: The paper illustrates the performance of the autonomous guidance system in a virtual reality environment (SYNTHIA) and in a real scenario achieving the proposed goal: to move autonomously from a starting point to a final point in a comfortable way.
83 citations
TL;DR: Simulation studies and comparisons are conducted to demonstrate the effectiveness and superiority of the proposed finite-time observer based guidance and control scheme for path following of an USV with time-varying and large sideslip angles and unknown external disturbances.
Abstract: Suffering from complex sideslip angles, path following control of an under actuated surface vehicle (USV) becomes significantly challenging and remains unresolved In this paper, a finite-time observer based guidance and control (FOGC) scheme for path following of an USV with time-varying and large sideslip angles and unknown external disturbances is proposed The salient features of the proposed FOGC scheme are as follows: 1) time-varying large sideslip angle is exactly estimated by a finite-time sideslip observer, and thereby contributing to the sideslip-tangent line-of-sight guidance law which significantly enhances the robustness of the guidance system to unknown sideslip angles which are significantly large and time-varying; 2) a finite-time disturbance observer (FDO) is devised to exactly observe unknown external disturbances, and thereby implementing FDO-based surge and heading robust tracking controllers, which possess remarkable tracking accuracy and precise disturbance rejection, simultaneously; and 3) by virtue of cascade analysis and Lyapunov approach, global asymptotic stability of the integrated guidance-control system is rigorously ensured Simulation studies and comparisons are conducted to demonstrate the effectiveness and superiority of the proposed FOGC scheme
81 citations
TL;DR: Advanced entry guidance systems could potentially enable future vehicles to generate feasible/optimal flight trajectories onboard for the latest mission requirements and track the new trajectories as well as generate feasible and optimal trajectories for new missions.
Abstract: Advanced entry guidance systems could potentially enable future vehicles to generate feasible/optimal flight trajectories onboard for the latest mission requirements and track the new trajectories ...
72 citations
TL;DR: The goals for and the pros and cons of guidance are listed, and the role that it can play not only in key low-level visualization tasks but also the more sophisticated model-generation tasks of visual analytics are discussed.
66 citations
21 May 2018
TL;DR: The proposed MPC COLAV method does not rely on an accurate model of the guidance system to achieve vessel behaviors that are compliant with the COLREGS, but depends on transitional costs in the MPC objective for collision avoidance maneuvers that are being executed by the marine vessel.
Abstract: This paper presents a viable approach for incorporating collision avoidance strategies into existing guidance and control systems on marine vessels. We propose a method that facilitates the use of simulation-based Model Predictive Control (MPC) for collision avoidance (COLAV) on marine vessels. Any COLAV strategy to be applied in real traffic must adhere to the international regulations for preventing collisions at sea (COLREGS). The proposed MPC COLAV method does not rely on an accurate model of the guidance system to achieve vessel behaviors that are compliant with the COLREGS. Rather, it depends on transitional costs in the MPC objective for collision avoidance maneuvers that are being executed by the marine vessel. Hence, it is straightforward to implement the MPC COLAV on different vessels without specific knowledge of the vessel's guidance strategy. Moreover, it offers the possibility to switch between different (possibly application specific) guidance strategies on the same vessel while running the same MPC COLAV algorithm. We present results from full scale experiments that show the viability of our method in different collision avoidance scenarios.
65 citations
08 Jan 2018
TL;DR: A new drag-energy scheme, based on the use of pseudospectral methods and convex optimization, is proposed, able to loss-less convexify the formulation, and allows for an e-cient automatic design of an optimal entry satisfying all the longitudinal constraints acting on the vehicle.
Abstract: In this paper a new drag-energy scheme, based on the use of pseudospectral methods and convex optimization, is proposed. One of the most successful technologies to deal with atmospheric entry is the class of drag-tracking schemes, a direct heritage of the Space Shuttle program. The method that we propose exploits the drag-dynamics, and allows for an effcient automatic design of an optimal entry profile satisfying all the longitudinal constraints acting on the vehicle. A new representation of the entry-guidance problem, able to loss-less convexify the formulation, is provided. Numerical simulations confirm the validity of the proposed scheme as tool for further improving the autonomy of modern entry guidance systems, with a mean final range-to-go error in the order of three hundred meters, and the capability to re-compute a complete constrained trajectory to meet the mission requirements.
45 citations
01 Dec 2018
TL;DR: This paper examines AGVs, the types of navigation systems available and the sensors employed by these systems.
Abstract: Automatic Ground Vehicles (AGVs), require guidance systems to navigate through their environment. The navigation system and sensors employed are dictated by the ambient conditions in that environment and the task to be completed by the AGV. This paper examines AGVs, the types of navigation systems available and the sensors employed by these systems.
43 citations
TL;DR: In this paper, a second-order nonlinear Nomoto model with disturbances is proposed as the vessel dynamic motion model after reviewing and comparing different ship motion models applied for path following control.
Abstract: Underactuated autonomous surface vehicles (ASVs) have stringent requirements on automatically tracking a predefined path. This paper proposes a model predictive control (MPC) approach based on adaptive line-of-sight (LOS) guidance for path following of ASVs. For the controller, a second-order nonlinear Nomoto model with disturbances is proposed as the vessel dynamic motion model after reviewing and comparing different ship motion models applied for path following control. For the guidance system, a novel adaptive LOS guidance with a variable acceptance circle radius is proposed to improve the precision of reference path tracking. Specifically, the acceptance circle radius is adapted with the angle between two adjacent straight segments of a reference path. Simulation experiments illustrate that the LOS guidance system with a variable acceptance circle radius results in smaller tracking errors compared with the fixed acceptance circle radius. The proposed path following method can track reference paths well even in the face of disturbances.
36 citations
TL;DR: The following paper presents the design and fabrication of an ostraciiform swimming robot and its navigation control and guidance system, which allows the vehicle to perform different missions autonomously once their profiles are received from the base station.
Abstract: The following paper presents the design and fabrication of an ostraciiform swimming robot and its navigation control and guidance system Compared to other biomimetic vehicles, the chosen architecture has a lower propulsive efficiency but is easier to waterproof and capable to withstand greater pressures To generate the alternating motion of the robot bio-inspired thruster, namely a plane fin, a transmission system was designed to replace the direct drive widely adopted in underwater biomimetic vehicles The mechanical efficiency of two alternative mechanisms capable to actuate the fin were computed according to a preliminary sizing of the robot and its targeted swimming performances Therefore, the more suitable solution was manufactured and installed aboard At the same time, a proper navigation, guidance and control architecture (NGC) was designed and then integrated in the robot main controller The proposed solution allows the vehicle to perform different missions autonomously once their profiles are received from the base station Preliminary tests results and future works are discussed in the final conclusions
35 citations
TL;DR: The results of the theoretical and numerical simulation on a training ship verify the invariability and excellent robustness of the proposed controller, which effectively eliminates system chattering, solves the problem of lateral drift of the ship, and maintains the following of the trajectory while simultaneously achieving global stability and robustness.
Abstract: The paper reports the design and tests of the planar autopilot navigation system in the three-degree-of-freedom (3-DOF) plane (surge, sway and yaw) for a ship. The aim of the tests was to check the improved maneuverability of the ship in open waters using the improved nonlinear control algorithm, developed based on the sliding mode control theory for the ship-trajectory tracking problem of under-actuated ships with static constraints, actuator saturation, and parametric uncertainties. With the integration of the simple increment feedback control law, the dynamic control strategy was developed to fulfill the under-actuated tracking and stabilization objectives. In addition, the LOS (line of sight) guidance system was applied to control the motion path, whereas the sliding mode controller was used to emulate the rudder angle and propeller rotational speed control. Firstly, simulation tests were performed to verify the validity of the basic model and the tracking control algorithm. Subsequently, full scale maneuverability tests were done with a novel container ship, equipped with trajectory tracking control and sliding mode controller algorithm, to check the dynamic stability performance of the ship. The results of the theoretical and numerical simulation on a training ship verify the invariability and excellent robustness of the proposed controller, which: effectively eliminates system chattering, solves the problem of lateral drift of the ship, and maintains the following of the trajectory while simultaneously achieving global stability and robustness.
33 citations
TL;DR: Considering the design challenges associated with monostatic and multi-static sensor implementations and looking at the performance predictions for different possible configurations, acoustic sensors show clear promises in navigation, proximity sensing, as well as obstacle detection and tracking.
Abstract: This paper presents the state-of-the-art and reviews the state-of-research of acoustic sensors used for a variety of navigation and guidance applications on air and surface vehicles. In particular, this paper focuses on echolocation, which is widely utilized in nature by certain mammals (e.g., cetaceans and bats). Although acoustic sensors have been extensively adopted in various engineering applications, their use in navigation and guidance systems is yet to be fully exploited. This technology has clear potential for applications in air and surface navigation/guidance for Intelligent Transport Systems (ITS), especially considering air and surface operations indoors and in other environments where satellite positioning is not available. Propagation of sound in the atmosphere is discussed in detail, with all potential attenuation sources taken into account. The errors introduced in echolocation measurements due to Doppler, multipath and atmospheric effects are discussed, and an uncertainty analysis method is presented for ranging error budget prediction in acoustic navigation applications. Considering the design challenges associated with monostatic and multi-static sensor implementations and looking at the performance predictions for different possible configurations, acoustic sensors show clear promises in navigation, proximity sensing, as well as obstacle detection and tracking. The integration of acoustic sensors in multi-sensor navigation systems is also considered towards the end of the paper and a low Size, Weight and Power, and Cost (SWaP-C) sensor integration architecture is presented for possible introduction in air and surface navigation systems.
01 Jan 2018
TL;DR: An integrated guidance system is proposed in this paper to combine obstacle avoidance and SLAM so that the robot can move to the desired location without colliding with any unexpected obstacles.
Abstract: This paper presents a mobile robot navigation control system based on integration of laser SLAM localization and real-time obstacle avoidance control to provide personnel guidance for daily-life services. The LiDAR SLAM localization system is implemented in a ROS software architecture, in which Cartographer SLAM is adopted and the adaptive Monte Carlo localization is employed onboard the robot. An integrated guidance system is proposed in this paper to combine obstacle avoidance and SLAM so that the robot can move to the desired location without colliding with any unexpected obstacles. A safety-weight parameter is used to integrate goal seeking controller with the obstacle avoidance controller. The experimental results show that the robot can localize itself and navigate to the target location while avoiding obstacles on the path.
TL;DR: The bio-inspired concept and electromagnetic finite element analysis-aided design and testing of an electromagnetic homing guidance system comprising of an underwater dock with 400AT of electromagnetic dipole coil excited with the 20 Hz power supply and a twin-thruster AUV equipped with a differential magnetometer system are described.
Patent•
23 Jan 2018
TL;DR: In this paper, a medical guidance system providing real-time, three-dimensional (3D) augmented reality (AR) feedback guidance to a novice user of medical equipment having limited medical training, to achieve improved diagnostic or treatment outcomes.
Abstract: A medical guidance system providing real-time, three-dimensional (3D) augmented reality (AR) feedback guidance to a novice user of medical equipment having limited medical training, to achieve improved diagnostic or treatment outcomes.
TL;DR: The three-dimensional multiple constrained guidance problem for a hypersonic gliding vehicle (HGV) against a stationary ground target in dive phase is investigated and the finite-time stability of closed-loop guidance system is proven through the Lyapunov technique.
Abstract: The three-dimensional multiple constrained guidance problem for a hypersonic gliding vehicle (HGV) against a stationary ground target in dive phase is investigated. A coupled nonlinear dynamic model is established on account of the bank-to-turn control scheme adopted by the HGV, which formulates the relation between line-of-sight angles and trajectory control variables. On this basis, a finite-time nonlinear disturbance observer is introduced to estimate the lumped uncertainty. Utilizing the estimation as feedforward compensation, a guidance law based on the adaptive multivariable super-twisting sliding mode control is designed to realize precise strike with designated impact angles. The finite-time stability of closed-loop guidance system is proven through the Lyapunov technique. Numerical simulations are executed to validate the mission adaptiveness and the robustness of the presented guidance scheme.
TL;DR: Numerical simulations demonstrate that the proposed terminal area energy management guidance system for an unpowered reusable launch vehicle (RLV) is capable of guiding the RLV to the desired touchdown conditions.
TL;DR: The paper aims to address the collision avoidance issue by using the dynamic predictive guidance technique using the Visual C++-based simulation framework including the ship's nonlinear dynamic model and the algorithm of numerical optimization.
TL;DR: An extended stereo visual simultaneous localization and mapping approach is proposed with optimization that deals with cross-session loop-closure detection and pose rectification for bounding estimation error as well as aligning the positions to global world frame.
Abstract: As industrial inspection and maintenance tasks in outdoor working environments are increasingly complex and flexible, wearable assistive system (WAS) has shown promising prospects, especially when the tasks are infrequent and unfamiliar to workers. Such tasks require more accurate and global ego-localization than using GPS. In this paper, a wearable-assisted navigation system is proposed for task-specific route guidance. This paper proposes to learn a global metric-topological abstract map of outdoor workspace using the combination of stereo cameras and inertial measurement units. An extended stereo visual simultaneous localization and mapping approach is proposed with optimization that deals with cross-session loop-closure detection and pose rectification for bounding estimation error as well as aligning the positions to global world frame. Thus, the system allows building and using globally consistent maps across sessions. A prototype of WAS is developed in which the augmentations of guidance are delivered to users via an optical see-through display. The system is evaluated by experiments designed as on-site inspection scenarios and the results validate the practicability and effectiveness of the system.
Patent•
05 Jan 2018
TL;DR: In this paper, a multi-robot mapping guidance system based on a cloud server and a mapping guidance method is presented, where robots can share map sources, the hardware configuration requirements for a single robot can be reduced, and moreover, the map building, perfecting and updating efficiency is easily improved.
Abstract: The invention discloses a multi-robot mapping guidance system based on a cloud server and a mapping guidance method. The multi-robot mapping guidance system based on the cloud server comprises the cloud server and a plurality of robots, and each robot can be in data connection with the cloud server; the mapping guidance method based on the system comprises the steps that cloud mapping is conductedaccording to the environmental data obtained through robot detection, and the data is issued to all the robots in the system so as to achieve network-construction guidance of the robots. By means ofthe multi-robot mapping guidance system based on the cloud server and the mapping guidance method, the robots can share map sources, the hardware configuration requirements for a single robot are reduced, the hardware cost can be saved, moreover, the map building, perfecting and updating efficiency is easily improved so that the robots can quickly conduct network construction, the cloud serve canknow the position distribution of the robots very well, and the unified allocation is conveniently achieved.
TL;DR: A designed high-order tracking differentiator was used to estimate states of systems in real time, which guarantees the feasibility of the designed algorithm and guarantees tracking precision and robustness, and backstepping sliding-mode control was adopted.
Abstract: This paper investigates the design of a missile seeker servo system combined with a guidance and control system. Firstly, a complete model containing a missile seeker servo system, missile guidance system, and missile control system (SGCS) was creatively proposed. Secondly, a designed high-order tracking differentiator (HTD) was used to estimate states of systems in real time, which guarantees the feasibility of the designed algorithm. To guarantee tracking precision and robustness, backstepping sliding-mode control was adopted. Aiming at the main problem of projectile motion disturbance, an adaptive radial basis function neural network (RBFNN) was proposed to compensate for disturbance. Adaptive RBFNN especially achieves online adjustment of residual error, which promotes estimation precision and eliminates the “chattering phenomenon”. The boundedness of all signals, including estimation error of high-order tracking differentiator, was especially proved via the Lyapunov stability theory, which is more rigorous. Finally, in considered scenarios, line of sight angle (LOSA)-tracking simulations were carried out to verify the tracking performance, and a Monte Carlo miss-distance simulation is presented to validate the effectiveness of the proposed method.
27 Mar 2018
TL;DR: The passive RFID tag is adopted to calibrate the important location of AGV to assist the AGV positioning and the kalman filter is used for data processing in the inertial guidance system.
Abstract: The guidance system is an important component of AGV. In order to obtain the guidance system with low cost, high flexibility and precision, a combinatorial inertial guidance method is proposed in this paper. The inertial guidance system is composed of the encoder and the inertial measurement unit (IMU). And, on this basis, the magnetic sensor (MS) is added to correct the cumulative error. Moreover, because the IMU and MS can't identify the current location of AGV, this paper adopts the passive RFID tag to calibrate the important location of AGV to assist the AGV positioning. In addition, in order to obtain more accurate control parameters, the kalman filter (KF) is used for data processing in the system. Finally, the experiments demonstrate the effectiveness and accuracy of the proposed system.
TL;DR: This paper focuses on the design of terminal impact angle constrained guidance laws, against maneuvering targets, for three-dimensional engagements, using numerical simulations for various engagement scenarios.
TL;DR: A methodology to estimate the stability of the ship in an automatic and unattended way, based on a frequency analysis of roll motion and on the estimation of the mass moment of inertia of the vessel, is presented.
TL;DR: Simulation results show the effectiveness of the proposed antidisturbance guidance law for tracking a maneuvering target with the arbitrary bounded velocity for target tracking.
Abstract: This paper is concerned with the target tracking problem of an autonomous surface vehicle in the presence of a maneuvering target. The velocity information of target is totally unknown to the follower vehicle, and only the relative distance and angle between the target and follower are obtained. First, a reduced-order extended state observer is used to estimate the unknown relative dynamics due to the unavailable velocity of the target. Based on the reduced-order extended state observer, an antidisturbance guidance law for target tracking is designed. The input-to-state stability of the closed-loop target tracking guidance system is analyzed via cascade theory. Furthermore, the above result is extended to the case that collisions between the target and leader are avoided during tracking, and a collision-free target tracking guidance law is developed. The main feature of the proposed guidance law is twofold. First, the target tracking can be achieved without using the velocity information of the target. Second, collision avoidance can be achieved during target tracking. Simulation results show the effectiveness of the proposed antidisturbance guidance law for tracking a maneuvering target with the arbitrary bounded velocity.
TL;DR: In this article, an adaptive autopilot for the intended system using model reference and self-tuning regulator with justification against previous work and reference flight data concerning the performance requirements of time responses and flight path characteristics is presented.
Abstract: The huge developments in computational capabilities facilitate the design and implementation of adaptive and robust control. Furthermore, the great developments in nanotechnology and its availability in civilian level with less cost, weight, and size attract the researchers all over the world towards embedded systems especially the embedded flight control. One of the real applications are the guided missiles especially the anti-tank guided missile systems which are launched against the ground and short-range targets and is called command line of sight. The present work is concerned with improving the performance of an anti-tank guided missile system belonging to the first generation via adaptive synthesis of guidance systems. The online system identification is required to complete the cycle of adaptive autopilot design. This paper is devoted to designing an adaptive autopilot for the intended system using model reference and self-tuning regulator with justification against previous work and reference flight data concerning the performance requirements of time responses and flight path characteristics. The new design is implemented within the 6-DOF simulation from which the obtained results clarify its capability to stabilize the system in presence of unmodeled dynamics and satisfy the performance requirements with disturbance rejection and measurement noise attenuation. Also, the flight path is evaluated considering the HIL environment.
03 Mar 2018
TL;DR: The goal was to develop a high-fidelity multiphysical simulation of such a HAPS, including a long-term mission planner, a reactive guidance system for weather avoidance, a flight control system with protections, a 6-DoF model with solar-electric propulsion system, and a comprehensive environment simulation with 4-D wind and turbulence.
Abstract: With advances made in the fields of energy generation from renewable sources, airborne electrical propulsion, and autonomous system operation, much activity has been directed towards the development of so called high altitude pseudo satellites (HAPS) in recent years, with Zephyr (Airbus) and Aquila (Facebook) as prominent examples. Compared to classical orbital satellites, these are designed to require lower deployment costs and to offer a high flexibility in operational tasks and a long mission endurance. In the project StraVARIA, the goal was to develop a high-fidelity multiphysical simulation of such a HAPS, including a long-term mission planner, a reactive guidance system for weather avoidance, a flight control system with protections, a 6-DoF model with solar-electric propulsion system, and a comprehensive environment simulation with 4-D wind and turbulence. Due to the long mission duration, the mission planner and guidance system offer an increased autonomy level compared to standard operator controlled UAVs, however human input is still required for high level planning. The acausal and object-oriented modeling language Modelica has been used to create the integrated simulation model, enabling a modular and detailed modeling approach. By automatic code generation and optimization, simulation efficiency is improved, which is an important factor when considering long-term missions. Results of the integrated simulation show that missions like area surveillance and communication relay are possible whenever adverse weather conditions can be avoided. Ascending to and descending from mission altitude of approximately 18 km also poses a threat to the lightweight HAPS construction since layers of stronger winds and atmospheric disturbance have to be passed. To this end, simulated example missions over Bavaria are presented showcasing these effects, where mission success is ensured by means of the long term mission planner, the reactive guidance, and the inner-level protections implemented in the flight control system.
TL;DR: The enhanced supernormal auditory interface improves performance by reducing the tracking error of both path following and trajectory tracking compared to a non-enhanced interface without the supernormal transformation.
TL;DR: A new three-dimensional missile guidance law that guarantees the intercept of maneuvering targets in finite time is developed in this paper.
Abstract: A new three-dimensional missile guidance law that guarantees the intercept of maneuvering targets in finite time is developed in this paper. The guidance law is designed via the finite-time input-t...