A Method for Searching Optimal Routes with Collision Avoidance on Raster Charts

2003 ◽  
Vol 56 (3) ◽  
pp. 371-384 ◽  
Author(s):  
Ki-Yin Chang ◽  
Gene Eu Jan ◽  
Ian Parberry
Keyword(s):  
Data Structure ◽  
Real Time ◽  
Collision Avoidance ◽  
Collision Detection ◽  
Linear Time ◽  
Routing Algorithm ◽  
Time And Space ◽  
Navigation Safety

Collision avoidance is an intensive discussion issue for navigation safety. This article introduces a new routing algorithm for finding optimal routes with collision detection and avoidance on raster charts or planes. After the required data structure of the raster chart is initialized, the maze routing algorithm is applied to obtain the particular route of each ship. Those ships that have potential to collide will be detected by simulating the particular routes with ship domains. The collision avoidance scheme can be achieved by using the collision-area-marking method with collision avoidance rules at sea. The algorithm has linear time and space complexities, and is sufficiently fast to perform real-time routing on the raster charts.

A New Method of Ship Routing on Raster Grids, with Turn Penalties and Collision Avoidance

2005 ◽  
Vol 59 (1) ◽  
pp. 27-42 ◽  
Author(s):  
Rafal Szlapczynski
Keyword(s):  
Real Time ◽  
Collision Avoidance ◽  
Linear Time ◽  
Ship Routing ◽  
Restricted Area ◽  
Collision Avoidance System ◽  
Priority Policy ◽  
Safe Path ◽  
Destination Point ◽  
General Method

The article introduces a method of finding optimal routes on raster planes. The method presented takes advantage of a new algorithm that tends to minimize a number of direction changes within a route, while steering clear of the obstacles. Two different schemes, suitable for restricted area Vessel Traffic Service (VTS) system and collision avoidance system located on the own ship are described. The VTS-oriented scheme supports VTS priority policy that may extend or override international give-way regulations. The own-ship routing scheme in a give-way situation is capable of determining the shortest safe path to the destination point. The method takes into account own ship dynamics. It has linear time and space complexities and therefore is sufficiently fast to perform real-time routing on the raster grids. Both the general method and the algorithm it uses are presented in detail in the paper. Implementation issues are also discussed.

REAL-TIME SELF-COLLISION AVOIDANCE SYSTEM FOR ROBOTS USING ROBE

2004 ◽  
Vol 01 (03) ◽  
pp. 533-550 ◽  
Author(s):  
FUMI SETO ◽  
KAZUHIRO KOSUGE ◽  
YASUHISA HIRATA
Keyword(s):  
Mobile Robot ◽  
Real Time ◽  
Collision Avoidance ◽  
Collision Detection ◽  
Reaction Force ◽  
Collision Avoidance System ◽  
Representation Method ◽  
Elastic Elements

In this paper, we propose a real-time self-collision avoidance system for robots which cooperate with a human/humans. First, the robot is represented by elastic elements. The representation method is referred to as RoBE (Representation of Body by Elastic elements). Elastic balls and cylinders are used as the elements to simplify collision detection, although elements of any shape could be used for RoBE. When two elements collide with each other, a reaction force is generated between them, and self-collision avoidance motion is generated by the reaction force. Experiments using the mobile robot with dual manipulators, referred to as MR Helper, illustrate the validity of the proposed system.

scholarly journals Using Real-Time Dynamic Prediction to Implement IoV-Based Collision Avoidance

2019 ◽  
Vol 9 (24) ◽  
pp. 5370
Author(s):  
Che-Cheng Chang ◽  
Wei-Ming Lin ◽  
Chuan-An Lai
Keyword(s):  
Object Detection ◽  
Real Time ◽  
Collision Avoidance ◽  
Collision Detection ◽  
Confidence Region ◽  
Dynamic Prediction ◽  
Internet Of Vehicles ◽  
Time Dynamic ◽  
The Future ◽  
Future Position

For some IoV-based collision-avoidance architectures, it is not necessary that all vehicles have communication abilities. Hence, they need some particular designs and extra components. In the literature, one of them uses a camera mounted onto the infrastructure at an intersection to realize collision detection. Consequently, technologies for real-time object detection and dynamic prediction are required for the purposes of collision avoidance. In this paper, we propose an interesting method to predict the future position of a vehicle based on a well-known, real-time object detection project, YOLOv3. Our algorithm utilizes the concept of vehicle dynamics and the confidence region to predict the future position on vehicles. This will help us to realize real-time dynamic prediction and Internet of Vehicles (IoV)-based collision detection. Lastly, in accordance with the experimental results, our design shows the performance for predicting the future position of a vehicle.

scholarly journals INDEXING GAPPED-FACTORS USING A TREE

2008 ◽  
Vol 19 (01) ◽  
pp. 71-87 ◽  
Author(s):  
PIERRE PETERLONGO ◽  
JULIEN ALLALI ◽  
MARIE-FRANCE SAGOT
Keyword(s):  
Data Structure ◽  
Pattern Matching ◽  
Suffix Tree ◽  
Linear Time ◽  
Fixed Size ◽  
Specific Kind ◽  
Time And Space ◽  
Inference Problems

We present a data structure to index a specific kind of factors, that is of substrings, called gapped-factors. A gapped-factor is a factor containing a gap that is ignored during the indexation. The data structure presented is based on the suffix tree and indexes all the gapped-factors of a text with a fixed size of gap, and only those. The construction of this data structure is done online in linear time and space. Such a data structure may play an important role in various pattern matching and motif inference problems, for instance in text filtration.

REEEC-AGENT: human driver cognition and emotions-inspired rear-end collision avoidance method for autonomous vehicles

SIMULATION ◽  
2021 ◽  
pp. 003754972110047
Author(s):  
Muhammad A Butt ◽  
Faisal Riaz ◽  
Yasir Mehmood ◽  
Somyyia Akram
Keyword(s):  
Real Time ◽  
Collision Avoidance ◽  
Collision Detection ◽  
Autonomous Vehicles ◽  
Affective Computing ◽  
Field Experiments ◽  
Road Traffic ◽  
Sensory System ◽  
Driving Mode ◽  
Human Driver

Rear-end collision detection and avoidance is one of the most crucial driving tasks of self-driving vehicles. Mathematical models and fuzzy logic-based methods have recently been proposed to improve the effectiveness of the rear-end collision detection and avoidance systems in autonomous vehicles (AVs). However, these methodologies do not tackle real-time object detection and response problems in dense/dynamic road traffic conditions due to their complex computation and decision-making structures. In our previous work, we presented an affective computing-inspired Enhanced Emotion Enabled Cognitive Agent (EEEC_Agent), which is capable of rear-end collision avoidance using artificial human driver emotions. However, the architecture of the EEEC_Agent is based on an ultrasonic sensory system which follows three-state driving strategies without considering the neighbor vehicles types. To address these issues, in this paper we propose an extended version of the EEEC_Agent which contains human driver-inspired dynamic driving mode controls for autonomous vehicles. In addition, a novel end-to-end learning-based motion planner has been devised to perceive the surrounding environment and regulate driving tasks accordingly. The real-time in-field experiments performed using a prototype AV demonstrate the effectiveness of this proposed rear-end collision avoidance system.

A Real Time Control Architecture for Continuously Managing Patients in a Care Unit

1995 ◽  
Vol 34 (05) ◽  
pp. 475-488
Author(s):  
B. Seroussi ◽  
J. F. Boisvieux ◽  
V. Morice
Keyword(s):  
Real Time ◽  
Linear Time ◽  
Treatment Plan ◽  
Control Architecture ◽  
Real Time Control ◽  
Time Representation ◽  
Time Control ◽  
Continuous Support ◽  
Definition Of ◽  
Computerized System

Abstract:The monitoring and treatment of patients in a care unit is a complex task in which even the most experienced clinicians can make errors. A hemato-oncology department in which patients undergo chemotherapy asked for a computerized system able to provide intelligent and continuous support in this task. One issue in building such a system is the definition of a control architecture able to manage, in real time, a treatment plan containing prescriptions and protocols in which temporal constraints are expressed in various ways, that is, which supervises the treatment, including controlling the timely execution of prescriptions and suggesting modifications to the plan according to the patient’s evolving condition. The system to solve these issues, called SEPIA, has to manage the dynamic, processes involved in patient care. Its role is to generate, in real time, commands for the patient’s care (execution of tests, administration of drugs) from a plan, and to monitor the patient’s state so that it may propose actions updating the plan. The necessity of an explicit time representation is shown. We propose using a linear time structure towards the past, with precise and absolute dates, open towards the future, and with imprecise and relative dates. Temporal relative scales are introduced to facilitate knowledge representation and access.

Thresholds of Time and Space

2020 ◽  
Vol 2 (3) ◽  
pp. 8-28
Author(s):  
Susan Milbrath
Keyword(s):  
Fifteenth Century ◽  
Real Time ◽  
Human Sacrifice ◽  
Time And Space ◽  
Animal Sacrifice ◽  
Cardinal Directions ◽  
Death Imagery

Analysis of the iconography in a directional almanac on Codex Borgia pages 49–52 invites comparison with almanacs in a related set of divinatory manuscripts known as the Borgia Group, but one aspect of the Codex Borgia almanac remains unique. It records real-time dates employing the central Mexican system of year dates that help identify the images as year-end rituals. These fifteenth-century dates correlate with the last twenty-day “month” in the year, known as Izcalli in the Valley of Mexico and neighboring Tlaxcala. Izcalli rituals in February involved drilling a new fire, the erection of sacred trees, and animal sacrifice, all of which appear on Borgia 49–52. During Izcalli, human sacrifice was performed only every fourth year, a pattern like that seen in the Codex Borgia and the Codex Cospi, where death imagery and decapitated humans appear prominently on the fourth year-bearer page, associated with the southern direction. Borgia Group codices also depict trees and birds representing the four cardinal directions. These are most prominent on Codex Fejérváry-Mayer page 1 in a cosmogram representing two different calendar formats, like those seen in the Borgia almanac. The 5 × 52-day format was used to measure the solar year and Venus cycle, and a second set of day signs appears in a 4 × 65-day pattern useful in calculating the fifty-two-year cycle and the Venus cycle. This provides a subtext for understanding the dates represented on Borgia 49–52 and the extension of the almanac on page 53, where the Venus almanac begins.

scholarly journals Graph-Based Construction of 3D Korean Giwa House Models

Buildings ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 68
Author(s):  
Mankyu Sung
Keyword(s):  
Data Structure ◽  
Computer Graphics ◽  
Real Time ◽  
Texture Image ◽  
Time Rate ◽  
Commercial Software ◽  
Spline Curve ◽  
High Level ◽  
Complicated Part ◽  
Different Parts

This paper proposes a graph-based algorithm for constructing 3D Korean traditional houses automatically using a computer graphics technique. In particular, we target designing the most popular traditional house type, a giwa house, whose roof is covered with a set of Korean traditional roof tiles called giwa. In our approach, we divided the whole design processes into two different parts. At a high level, we propose a special data structure called ‘modeling graphs’. A modeling graph consists of a set of nodes and edges. A node represents a particular component of the house and an edge represents the connection between two components with all associated parameters, including an offset vector between components. Users can easily add/ delete nodes and make them connect by an edge through a few mouse clicks. Once a modeling graph is built, then it is interpreted and rendered on a component-by-component basis by traversing nodes in a procedural way. At a low level, we came up with all the required parameters for constructing the components. Among all the components, the most beautiful but complicated part is the gently curved roof structures. In order to represent the sophisticated roof style, we introduce a spline curve-based modeling technique that is able to create curvy silhouettes of three different roof styles. In this process, rather than just applying a simple texture image onto the roof, which is widely used in commercial software, we actually laid out 3D giwa tiles on the roof seamlessly, which generated more realistic looks. Through many experiments, we verified that the proposed algorithm can model and render the giwa house at a real time rate.

Design and implementation of decoupled periodic control scheme for a laboratory-based quadruple-tank process

2021 ◽  
pp. 095965182110228
Author(s):  
Jatin K Pradhan ◽  
Arun Ghosh
Keyword(s):  
Real Time ◽  
High Frequency ◽  
Linear Time ◽  
Disturbance Attenuation ◽  
Minimum Phase ◽  
Periodic Control ◽  
Linear Time Invariant ◽  
Control Scheme ◽  
Gain Margin ◽  
Time Invariant

It is well known that linear time-invariant controllers fail to provide desired robustness margins (e.g. gain margin, phase margin) for plants with non-minimum phase zeros. Attempts have been made in literature to alleviate this problem using high-frequency periodic controllers. But because of high frequency in nature, real-time implementation of these controllers is very challenging. In fact, no practical applications of such controllers for multivariable plants have been reported in literature till date. This article considers a laboratory-based, two-input–two-output, quadruple-tank process with a non-minimum phase zero for real-time implementation of the above periodic controller. To design the controller, first, a minimal pre-compensator is used to decouple the plant in open loop. Then the resulting single-input–single-output units are compensated using periodic controllers. It is shown through simulations and real-time experiments that owing to arbitrary loop-zero placement capability of periodic controllers, the above decoupled periodic control scheme provides much improved robustness against multi-channel output gain variations as compared to its linear time-invariant counterpart. It is also shown that in spite of this improved robustness, the nominal performances such as tracking and disturbance attenuation remain almost the same. A comparison with [Formula: see text]-linear time-invariant controllers is also carried out to show superiority of the proposed scheme.

Sign in / Sign up

Export Citation Format

Share Document