Optimal Path Smoothing while Maintaining a Region of Safe Operation

2021 ◽  
Author(s):  
Justin Whitaker ◽  
Greg Droge
Keyword(s):  
Optimal Path ◽  
Safe Operation ◽  
Path Smoothing

scholarly journals Development of an Improved Rapidly Exploring Random Trees Algorithm for Static Obstacle Avoidance in Autonomous Vehicles

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2244
Author(s):  
S. M. Yang ◽  
Y. A. Lin
Keyword(s):  
Path Planning ◽  
Obstacle Avoidance ◽  
Autonomous Vehicles ◽  
Autonomous Vehicle ◽  
Optimal Path ◽  
Random Trees ◽  
Average Deviation ◽  
Lane Changes ◽  
Path Smoothing ◽  
Rapidly Exploring Random Trees

Safe path planning for obstacle avoidance in autonomous vehicles has been developed. Based on the Rapidly Exploring Random Trees (RRT) algorithm, an improved algorithm integrating path pruning, smoothing, and optimization with geometric collision detection is shown to improve planning efficiency. Path pruning, a prerequisite to path smoothing, is performed to remove the redundant points generated by the random trees for a new path, without colliding with the obstacles. Path smoothing is performed to modify the path so that it becomes continuously differentiable with curvature implementable by the vehicle. Optimization is performed to select a “near”-optimal path of the shortest distance among the feasible paths for motion efficiency. In the experimental verification, both a pure pursuit steering controller and a proportional–integral speed controller are applied to keep an autonomous vehicle tracking the planned path predicted by the improved RRT algorithm. It is shown that the vehicle can successfully track the path efficiently and reach the destination safely, with an average tracking control deviation of 5.2% of the vehicle width. The path planning is also applied to lane changes, and the average deviation from the lane during and after lane changes remains within 8.3% of the vehicle width.

scholarly journals Collision Free Smooth Path for Mobile Robots in Cluttered Environment Using an Economical Clamped Cubic B-Spline

Symmetry ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1567
Author(s):  
Iram Noreen
Keyword(s):  
Mobile Robots ◽  
Execution Time ◽  
Path Length ◽  
Mobile Robotics ◽  
Optimal Path ◽  
Post Processing ◽  
B Spline ◽  
Smooth Path ◽  
Path Smoothing ◽  
Narrow Passage

Mobile robots have various applications in agriculture, autonomous cars, industrial automation, planetary exploration, security, and surveillance. The generation of the optimal smooth path is a significant aspect of mobile robotics. An optimal path for a mobile robot is measured by various factors such as path length, path smoothness, collision-free curve, execution time, and the total number of turns. However, most of the planners generate a non-smooth less optimal and linear piecewise path. Post processing smoothing is applied at the cost of increase in path length. Moreover, current research on post-processing path smoothing techniques does not address the issues of post smoothness collision and performance efficiency. This paper presents a path smoothing approach based on clamped cubic B-Spline to resolve the aforementioned issues. The proposed approach has introduced an economical point insertion scheme with automated knot vector generation while eliminating post smoothness collisions with obstacles. It generates C2 continuous path without any stitching point and passes more closely to the originally planned path. Experiments and comparison with previous approaches have shown that the proposed approach generates better results with reduced path length, and execution time. The test cases used for experiments include a simple structure environment, complex un-structured environment, an environment full of random cluttered narrow obstacles, and a case study of an indoor narrow passage.

Bereavement: Is There an Optimal Path to Recovery?

1984 ◽  
Vol 29 (8) ◽  
pp. 632-634
Author(s):  
Berit Ingersoll-Dayton
Keyword(s):  
Optimal Path

Association between Socioeconomic Factors and Postoperative Complications of Cholecystectomy

2021 ◽  
pp. 1-13
Author(s):  
Herman Romero Ramírez ◽  
Norma Muñoz Albán ◽  
Consuelo Albán Meneses ◽  
Alicia Escobar Torres
Keyword(s):  
Laparoscopic Cholecystectomy ◽  
Postoperative Complications ◽  
Socioeconomic Factors ◽  
Control Variable ◽  
Laparoscopic Technique ◽  
Safe Operation ◽  
Conventional Surgery ◽  
Socioeconomic Characteristics ◽  
Dependent Variables ◽  
Education Levels

The article´s goal isto determine if socioeconomic factors influence the postoperative complications of cholecystectomy. For this, the observational study was defined, analytical and quantitative study was conducted in 100 patients who underwent cholecystectomy. A logistic regression model was applied in which risk factors, socioeconomic characteristics, along with a control variable, were incorporated as variables. Three models were run with alternative dependent variables that are delimited by the type of postoperative complication recorded. The results found showed that women show a higher risk of presenting complications after cholecystectomy, the same occurs in older patients. Likewise, the risk is much lower in people with higher education levels and in patients who underwent laparoscopic cholecystectomy, they only have a 5% risk of presenting complications. Postoperative complications after cholecystectomy are minimized by using the laparoscopic technique and socioeconomic factors would influence the risk of suffering postoperative complications after said surgery, which makes laparoscopic cholecystectomy a safe operation with many other benefits and advantages over traditional or conventional surgery.

Improving the methods to improve the stability of hydrotechnical structures in Yakutia

2020 ◽  
pp. 37-39
Author(s):  
M LOSKIN
Keyword(s):  
Agricultural Production ◽  
Hydraulic Engineering ◽  
Process Water ◽  
Small Rivers ◽  
Limiting Factor ◽  
Safe Operation ◽  
Central Yakutia ◽  
Agricultural Water Supply ◽  
Temperature Impact ◽  
The Stability

Problems of providing the population and agricultural production by qualitative potable and process water in the Central Yakutia are covered. This territory belongs to the region with acute shortage of water resources which is always a limiting factor of development of agricultural production. For the solution of this burning issue in the 80th years of the last century along the small rivers the systems of hydraulic engineering constructions providing requirements with process water practically of all settlements of the Central Yakutia were constructed. At a construction of all hydraulic engineering buildings the method of construction with preservation of soils of the basis of constructions in a frozen state was applied. When warming the climate which is observed in recent years hydraulic engineering constructions built in regions of a wide spread occurance of breeds of an ice complex and with the considerable volume of water weight, were especially vulnerable. On character and a design they experience continuous threat of damage and demand very attentive relation from the operating organizations. Taking this into account, safe operation of hydraulic engineering constructions in a zone of distribution of permafrost breeds demands new approaches. The article examines features of hydraulic engineering constructions’ operation of agricultural water supply objects in the Central Yakutia. Distinctiveness of hydraulic engineering constructions’ operation is that stability of constructions is intimately bound to temperature impact of a reservoir on ground dams’ body and the basis of constructions. The possibility of inclusion of ways for an intensification of a freezing of constructions in the structure of operational actions is studied. The new method on safe operation of hydraulic engineering constructions as prewinter abatement of the water level in a reservoir accounting volumes and norms of water consumption of the settlement is offered.

PERAN DESIGNATED PERSON ASHORE (DPA) DALAM PENGOPERASIAN KAPAL YANG AMAN SESUAI KETENTUAN NASIONAL DAN INTERNASIONAL

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Suganjar Suganjar ◽  
Renny Hermawati
Keyword(s):  
Marine Environment ◽  
Emergency Preparedness ◽  
Safety Management ◽  
Shipping Industry ◽  
Safe Operation ◽  
International Regulation ◽  
Loss Of Life ◽  
Shipping Company ◽  
Environmental Protection Policy ◽  
Human Injury

<p><em>Safety management in the shipping industry is based on an international regulation. It is International Safety Management Code (ISM-Code) which is a translation of SOLAS ‘74 Chapter IX. It stated that t</em><em>he objectives of the Code are to ensure safety at sea, prevention of human injury or loss of life, and avoidance of damage to the environment, in particular, to the marine environment, and to property.it is also</em><em> requires commitment from top management to implementation on both company and on board. The implementation of the ISM-Code is expected to make the ship’s safety is more secure. The ISM-Code fulfillment refers to 16 elements, there are; General; Safety and Environmental Protection Policy; Company Responsibility and Authority; Designated Person(s); Master Responsibility and Authority; Resources and Personnel; Shipboard Operation; Emergency Preparedness; Report and Analysis of Non-conformities, Accidents and Hazardous Occurrences; Maintenance of the Ship and Equipment; Documentation; Company Verification, Review, and Evaluation;  Certification and Periodical Verification; Interim Certification; Verification; Forms of Certificate. The responsibility and authority of Designated Person Ashore / DPA in a shipping company is regulated in the ISM-Code. So, it is expected that DPA can carry out its role well, than can minimize the level of accidents in each vessels owned/operated by each shipping company.</em></p><p><em></em><strong><em>Keywords :</em></strong><em> ISM Code,</em><em> </em><em>Safety management, </em><em>Designated Person Ashore</em></p><p> </p><p> </p><p>Manajemen keselamatan di bidang pelayaran saat ini diimplementasikan dalam suatu peraturan internasional yaitu <em>International Safety Management Code</em> (<em>ISM-Code</em>) yang merupakan penjabaran dari <em>SOLAS 74 Chapter IX</em>-<em>Management for the safe operation of ships</em>. Tujuan dari <em>ISM-Code</em> <em>“The objectives of the Code are to ensure safety at sea, prevention of human injury or loss of life, and avoidance of damage to the environment, in particular, to the marine environment, and to property”</em> dan  <em>ISM-Code</em> menghendaki adanya komitmen dari manajemen tingkat puncak sampai pelaksanaan, baik di darat maupun di kapal.  Pemberlakuan <em>ISM-Code</em> tersebut diharapkan akan membuat keselamatan kapal menjadi lebih terjamin. Pemenuhan <em>ISM-Code</em> mengacu kepada 16 elemen yang terdiri dari ; umum; kebijakan keselamatan  dan perlindungan lingkungan; tanggung jawab dan wewenang perusahaan; petugas yang ditunjuk didarat; tanggung jawab dan wewenang nahkoda; sumber daya dan personil; pengopersian kapal; kesiapan menghadapi keadaan darurat; pelaporan dan analisis ketidaksesuaian, kecelakaan dan kejadian berbahaya; pemeliharaan kapal dan perlengkapan;  Dokumentasi; verifikasi, tinjauan ulang, dan evaluasi oleh perusahaan; sertifikasi dan verifikasi berkala; sertifikasi sementara; verifikasi; bentuk sertifikat. Tugas dan tanggungjawab <em>Designated Person Ashore/DPA </em>didalam suatu perusahaan pelayaran<em>, </em>telah diatur di dalam <em>ISM-Code.</em>  Sehingga diharapkan agar DPA dapat melaksanakan peranannya dengan baik, sehingga dapat menekan tingkat kecelakaan di setiap armada kapal yang dimiliki oleh setiap perusahaan pelayaran.</p><p class="Style1"><strong>Kata kunci</strong> : <em>ISM Code</em>, Manajemen keselamatan, <em>Designated Person Ashore</em></p>

Analysis and Decision of Optimal Path of Forest Disaster Patrol Based on Beidou Navigation

2020 ◽  
Author(s):  
Jinyi Ma ◽  
Lifu Hu ◽  
Bini Pan ◽  
Zhongzhi Li ◽  
Yuqing Tian ◽  
...  
Keyword(s):  
Optimal Path
Sign in / Sign up

Export Citation Format

Share Document