A novel collision cone approach is proposed as an aid to collision detection and avoidance between irregularly shaped moving objects with unknown trajectories. It is shown that the collision cone can be effectively used to determine whether collision between a robot and an obstacle (both moving in a dynamic environment) is imminent. No restrictions are placed on the shapes of either the robot or the obstacle, i.e., they can both be of any arbitrary shape. The collision cone concept is developed in a phased manner starting from existing analytical results that enable prediction of collision between two moving point objects. These results are extended to predict collision between a point and a circular object, between a point and an irregularly shaped object, between two circular objects, and finally between two irregularly shaped objects. Using the collision cone approach, several strategies that the robot can follow in order to avoid collision, are presented. A discussion on how the shapes of the robot and obstacles can be approximated in order to reduce computational burden is also presented. A number of examples are given to illustrate both collision prediction and avoidance strategies of the robot.

/pdf/obstacle-avoidance-in-a-dynamic-environment-a-collision-cone-1phso2jk3m.pdf

Obstacle avoidance in a dynamic environment: a collision cone approach

Missile guidance and pursuit

A mix between a monograph and an article collection, this PhD thesis considers the concept of guided motion control for marine vehicles, in particular focusing on underactuated marine surface vehicles. The motion control scheme is defined to involve the combination of a guidance system which issues meaningful velocity commands with a velocity control system which has been specifically designed to take vehicle maneuverability and agility constraints into account when fulfilling these commands such that a given motion control objective can be achieved in a controlled and feasible manner without driving the vehicle actuators to saturation. Furthermore, motion control scenarios are classified in a novel way according to whether they involve desired motion which has been defined a priori or not. Consequently, in addition to the classical scenarios of point stabilization, trajectory tracking, path following and maneuvering, the so-called target tracking scenario is considered. The resulting scenarios then involve target tracking, path following, path tracking and path maneuvering. In addition, it is proposed to define the control objectives associated with each scenario as work-space tasks instead of configurationspace tasks. Such a choice seems better suited for practical applications, since most vehicles operate in an underactuated configuration exposed to some kind of environmental disturbances. The thesis also proposes a novel mechanization of constant bearing guidance, which is a classical guidance principle well-known in the guided missile literature. This suggestion is motivated by a need to solve the target tracking motion control objective for marine vehicles. The proposed implementation enables explicit specification of the transient rendezvous behavior toward the target by selection of two intuitive tuning parameters. In addition, a singularity-free guidance law applicable to path following scenarios involving regularly parameterized paths which do not need to be arc-length parameterized is proposed. An extension to this guidance law is also suggested in order to enable off-path traversing of regularly parameterized paths for formation control purposes. A novel velocity control system which inherently takes maneuverability, agility and actuator constraints into account is developed for the purpose of controlling underactuated marine vehicles moving at high speed. The system is derived through a design method which involves a control-oriented modeling approach and requires a minimum of system identification tests to be carried out. The thesis also gives a novel overview of the major developments in marine control systems as seen from a Norwegian perspective. The development can be viewed as three waves of control, where the first wave concerned development of novel ship automation technology in the 1960s and 1970s, the second wave involved development of unique dynamic positioning systems in the 1970s and 1980s, while the third wave is expected to encompass the development of unmanned vehicle technology for a large number of maritime applications. A summary of the historical development, present status and future possibilities associated with unmanned surface vehicles (USVs) is also given. Current Norwegian activities are particularly emphasized. Furthermore, an overview of the main formation control concepts applicable to marine surface vehicles is given. A novel formation control functionality named coordinated target tracking is subsequently suggested within a leader-follower framework. Employing a guided motion control system using the suggested mechanization of constant bearing guidance, this functionality is then implemented for two different types of underactuated USVs such that they are able to move in formation with a leader vessel which can maneuver freely without being constrained to any predefined motion pattern. In particular, excerpts from successful full-scale formation control experiments involving a manned leader vessel and the two USVs executing coordinated target tracking at high speed are presented. This functionality currently seems to be unique on a worldwide basis, providing a convenient plug-and-play formation control capability for manned leader vessels involved in maritime survey operations.

/pdf/guidance-laws-for-autonomous-underwater-vehicles-1mbavf5au5.pdf

Guidance Laws for Autonomous Underwater Vehicles

Current air-to-air missile guidance and control technology is assessed. Areas explored include target state estimation, advanced guidance laws, and bank-to-turn autopilots. The assumptions, benefits, and limitations of recent applications of nonlinear filtering, adaptive filtering, modern control, adaptive control, dual control, differential game theory, and modern control design techniques to the air-to-air missile problem are discussed. >

Assessment of air-to-air missile guidance and control technology

A new adaptive nonlinear guidance law is proposed here. The fourth order state equation for integrated guidance and control loop is formulated taking into consideration the target uncertainties and control loop dynamics. The state equation is further changed into the normal form by nonlinear coordinate transformation. Using the normal form of state equation, an adaptive nonlinear guidance law is proposed to compensate for the uncertainties in both target acceleration and control loop dynamics. The proposed law adopts the sliding mode control approach with adaptation for unknown bound of uncertainties. The present approach can effectively solve the existing guidance problem against target maneuver and the limited performance of control loop. We have provided the stability analyses and performed simulations comparing favorably our approach to the state of the art.

Adaptive nonlinear guidance law considering control loop dynamics

Introduction G laws for short-range tactical missiles have become a well-researched topic over the past 35 years with publications of analytical treatment and implementation of missile guidance going back to the 1940's Thus, much of the guidance development available in the literature predates that which is known as modern control theory These early concepts, now commonly referred to as classical guidance, have been used from that time to the present to command missiles during their homing phases of flight to target impact To the extent that assumptions of comparable relative velocity and certain conditions on relative bearing between the pursuer and target were valid, the classical guidance techniques remained adequate However, evidence is evolving which suggests that the performance of present weapon systems may be seriously degraded in engagements against targets with predicted characteristics of the 1990's and beyond and in the battlefield environments of that time frame It has been established that the guidance laws currently in wide use may not be adequate in defeating those threats Thus, it is projected that fundamental advances in the application of control systems theory is required to enhance the guidance effectiveness of future missile weapon systems Additionally, missile air frame and propulsion systems also may require advances appropriate to defeat predicted targets In particular, air defense and air-to-air weapons currently undergoing research and development utilizing classical guidance technology may be seriously hampered in the combat scenarios envisioned In evaluating the extensive literature on guidance laws applicable to short-range missiles, the lack of a suitable survey became apparent Although excellent reviews of related topics such as optimal control' and sensitivity methods had appeared while those fields were relatively young, the missile guidance literature was found to be highly decentralized and fragmented This may be attributed, in part, to the fact that literature for guidance laws was usually classified for security purposes These works were rarely published beyond internal industrial reports, and though not made public they became reference documentation for missile designers spanning a period of over 35 years With classical techniques implemented even in today's highly sophisticated systems, the literature gave credence to a widely accepted definition of classical terminal homing and defined its extensions into the modern era It was observed that guidance laws typically fit within the following five categories, the first three of which are the well-known classical techniques: lineof-sight (LOS), pursuit, proportional navigation guidance

Guidance Laws for Short-Range Tactical Missiles

Introduction G laws for short-range tactical missiles have become a well-researched topic over the past 35 years with publications of analytical treatment and implementation of missile guidance going back to the 1940's. Thus, much of the guidance development available in the literature predates that which is known as modern control theory. These early concepts, now commonly referred to as classical guidance, have been used from that time to the present to command missiles during their homing phases of flight to target impact. To the extent that assumptions of comparable relative velocity and certain conditions on relative bearing between the pursuer and target were valid, the classical guidance techniques remained adequate. However, evidence is evolving which suggests that the performance of present weapon systems may be seriously degraded in engagements against targets with predicted characteristics of the 1990's and beyond and in the battlefield environments of that time frame. It has been established that the guidance laws currently in wide use may not be adequate in defeating those threats. Thus, it is projected that fundamental advances in the application of control systems theory is required to enhance the guidance effectiveness of future missile weapon systems. Additionally, missile air frame and propulsion systems also may require advances appropriate to defeat predicted targets. In particular, air defense and air-to-air weapons currently undergoing research and development utilizing classical guidance technology may be seriously hampered in the combat scenarios envisioned. In evaluating the extensive literature on guidance laws applicable to short-range missiles, the lack of a suitable survey became apparent. Although excellent reviews of related topics such as optimal control' and sensitivity methods had appeared while those fields were relatively young, the missile guidance literature was found to be highly decentralized and fragmented. This may be attributed, in part, to the fact that literature for guidance laws was usually classified for security purposes. These works were rarely published beyond internal industrial reports, and though not made public they became reference documentation for missile designers spanning a period of over 35 years. With classical techniques implemented even in today's highly sophisticated systems, the literature gave credence to a widely accepted definition of classical terminal homing and defined its extensions into the modern era. It was observed that guidance laws typically fit within the following five categories, the first three of which are the well-known classical techniques: lineof-sight (LOS), pursuit, proportional navigation guidance

Guidance laws for short range tactical missiles

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

M. E. Warren

Author Tools

Chat about Author

Papers

Guidance Laws for Short-Range Tactical Missiles

Guidance laws for short range tactical missiles