Study on the occlusion of the visibility window on highway exit ramps

2021 ◽  
pp. 002072092199977
Author(s):  
Jian Xiao ◽  
Zhongxiang Huang ◽  
Yu Li ◽  
Liulin Yang ◽  
Juanxia He ◽  
...  
Keyword(s):  
High Speed ◽  
Traffic Accidents ◽  
Line Of Sight ◽  
Target Area ◽  
Lane Changes ◽  
Theoretical Support ◽  
Roadside Vegetation ◽  
Occlusion Model ◽  
Visible Area ◽  
Exit Ramp

Traffic accidents frequently occur at the nose of highway exit ramps for a variety of reasons. When attempting to take an exit, a driver’s line of sight may be obscured by the curvature or slope of the main expressway, roadside vegetation, traffic signs, and other vehicles traveling alongside. These increase the likelihood of accidents due to inaccurate or poor driver judgement when approaching a highway exit. Because of emotional responses that accompany the possibility of missing an exit, many drivers act irrationally through haphazard acceleration or braking, aggressive lane changes; in some cases, even coming to a complete stop and reversing against the flow of high speed traffic to correct their course. This study applies to curved highway exit corridors with a poor line of sight. The total visible area of the exit ramp is defined in accordance with the design specifications of both the highway routes and exit ramps, which was then further refined by considering the driving characteristics of both the drivers and of surrounding traffic. This study set out to establish a reliable occlusion model of highway exits with the following goals in mind. Geometric equations describing the area and volume of the target area of the exit ramp are established. Discrete expression equation was deployed to establish the occlusion model for the target area within the visual field. Parameters taken from specifications of the Hunan section of the Shanghai-Kunming Expressway are used for multiple calculations, in which obstruction patterns of objects with the same width, and objects with different width at different positions are analyzed. Based on the patterns observed from stimulated experiments mentioned above, multiple effective measures were proposed to prevent the obstruction of the highway exit ramp. In summary, this study provides theoretical support for prevention of obstruction as well as an anti-occlusion model for better identification of the highway exit ramps by intelligent vehicle systems.

scholarly journals Influence of Whey Protein Micro-Gel Particles and Whey Protein Micro-Gel Particles-Xanthan Gum Complexes on the Stability of O/W Emulsions

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2301
Author(s):  
Man Zhang ◽  
Bin Liang ◽  
Hongjun He ◽  
Changjian Ji ◽  
Tingting Cui ◽  
...  
Keyword(s):  
Oxidative Stability ◽  
Whey Protein ◽  
High Speed ◽  
Xanthan Gum ◽  
Physical Stability ◽  
Theoretical Support ◽  
Gel Particles ◽  
Oil In Water ◽  
The Stability ◽  
The Impact

Appropriate pretreatment of proteins and addition of xanthan gum (XG) has the potential to improve the stability of oil-in-water (O/W) emulsions. However, the factors that regulate the enhancement and the mechanism are still not clear, which restricts the realization of improving the emulsion stability by directional design of its structure. Therefore, the effects of whey protein micro-gel particles (WPMPs) and WPMPs-XG complexes on the stability of O/W emulsion were investigated in this article to provide theoretical support. WPMPs with different structures were prepared by pretreatment (controlled high-speed shear treatment of heat-set WPC gels) at pH 3.5–8.5. The impact of initial WPC structure and XG addition on Turbiscan Indexes, mean droplet size and the peroxide values of O/W emulsions was investigated. The results indicate that WPMPs and XG can respectively inhibit droplet coalescence and gravitational separation to improve the physical stability of WPC-stabilized O/W emulsions. The pretreatment significantly enhanced the oxidative stability of WPC-stabilized O/W emulsions. The addition of XG did not necessarily enhance the oxidative stability of O/W emulsions. Whether the oxidative stability of the O/W emulsion with XG is increased or decreased depends on the interface structure of the protein-XG complex. This study has significant implications for the development of novel structures containing lipid phases that are susceptible to oxidation.

scholarly journals Development of a Road Condition Information System using Augmented Reality Technology on Smartphones

2020 ◽  
Vol 10 (2) ◽  
pp. 49-55
Keyword(s):  
Information System ◽  
Augmented Reality ◽  
High Speed ◽  
Human Error ◽  
Traffic Accidents ◽  
Road Traffic ◽  
Data Conversion ◽  
The Road ◽  
Road Condition ◽  
Augmented Reality Technology

Recently, accidents involving ground transportations are getting worse and more serious. Indonesian State Police (Korlantas POLRI) recorded the number of accidents in 2018 as many as 109,215 accidents. The number has incresed 4.69 percent compared to 2017 as many as 104,327 events. Road traffic accidents are caused by human error, the driver in this case. The driver's mistake is influenced by several factors, one of them is they cannot expect the road condition when they drive a vehicle at high speed. To solve this problem, drivers need information that can show road conditions. So, we present a new approach for detecting damaged roads by applying augmented reality technology. This research produces a road condition information system to help drivers get information about road conditions via smartphone. This system uses augmented reality technology with a markerless GPS Based Tracking method. The development of this system requires several stages such as collecting the data, data conversion, data classification, and views road condition. The researchers gathered the road condition data from the Public Work Department Semarang. This department itself undertakes a task to control the road condition in Semarang The trial of this system includes all drivers in Semarang city. Based on the results of the questionnaire responded to by 93 respondents, this test obtained an average value of 68%. So this system gets a pretty good response from the driver. Through this system, all drivers can avoid the damaged road condition which can cause traffic-congested and accident.

scholarly journals Controllers to Chase a High-Speed Evader Using a Pursuer with Variable Speed

2018 ◽  
Vol 8 (10) ◽  
pp. 1976 ◽  
Author(s):  
Jonghoek Kim
Keyword(s):  
Optical Flow ◽  
High Speed ◽  
Angular Rate ◽  
Relative Distance ◽  
Line Of Sight ◽  
Terminal Phase ◽  
Relative Speed ◽  
Variable Speed

This paper proposes a chasing controller to enable a pursuer to chase a high-speed evader such that the relative distance between the evader and the pursuer monotonically decreases as time passes. Our controller is designed to assure that the angular rate of Line-of-Sight joining the pair (the pursuer and the evader) is exactly zero at all time indexes. Assuming that the pursuee can readily observe optical flow, but only poorly detect looming, this pursuer’s movement is hardly detected by the pursuee. Consider the terminal phase when the pursuer is sufficiently close to the evader. As we slow down the relative speed of the pursuer with respect to the evader, we can reduce the probability of missing the high-speed evader. Thus, our strategy is to make the pursuer decrease its speed in the terminal phase, while ensuring that the distance between the evader and the pursuer monotonically decreases as time passes. The performance of our controller is verified utilizing MATLAB simulations.

scholarly journals Line of Sight Correction of High-Speed Liquid Crystal Using Overdriving Technology

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1477
Author(s):  
Hongyang Guo ◽  
Qing Li ◽  
Yangjie Xu ◽  
Yongmei Huang ◽  
Shengping Du
Keyword(s):  
Liquid Crystal ◽  
Response Time ◽  
High Speed ◽  
Pulse Width Modulation ◽  
Response Speed ◽  
Line Of Sight ◽  
Processing Unit ◽  
Driving Voltage ◽  
Light Modulator ◽  
Central Processing

In the line of sight correction system, the response time of the liquid crystal spatial light modulator under the normal driving voltage is too long to affect system performance. On the issues, an overdriving method based on a Field-Programmable Gate Array (FPGA) is established. The principle of the overdrive is to use a higher voltage difference to achieve a faster response speed of liquid crystal. In this scheme, the overdriving look-up table is used to seek the response time of the quantized phase, and the liquid crystal electrode is driven by Pulse–Width Modulation (PWM). All the processes are performed in FPGA, which releases the central processing unit (CPU) memory and responds faster. Adequate simulations and experiments are introduced to demonstrate the proposed method. The overdriving experiment shows that the rising response time is reduced from 530 ms to 34 ms, and the falling time is from 360 ms to 38 ms under the overdriving voltage. Typical light tracks are imitated to evaluate the performance of the line of sight correction platform. Results show that using the overdrive the −3 dB rejection frequency was increased from 1.1 Hz to 2.6 Hz. The suppression ability of the overdrive is about −20 dB at 0.1 Hz, however the normal-driving suppression ability is only about −13 dB.

Microstructure Evolution in Preparation of Cu-Sn Contact Wire for High-speed Railway

2011 ◽  
Vol 415-417 ◽  
pp. 446-451 ◽  
Author(s):  
Ming Yan ◽  
Yu Cai Wu ◽  
Jing Chao Chen ◽  
Xiao Long Zhou
Keyword(s):  
Microstructure Evolution ◽  
High Speed ◽  
High Speed Railway ◽  
Contact Wire ◽  
Evolution Rule ◽  
Theoretical Support

The thesis studies the microstructure evolution rule during Cu-Sn alloy preparation and processing process and its influence on material performance, provides necessary theoretical support for industrialization development of Cu-Sn contact wire for high-speed railway.

Problem Driving Maneuvers of Elderly Drivers

2003 ◽  
Vol 1843 (1) ◽  
pp. 89-95 ◽  
Author(s):  
Susantha Chandraratna ◽  
Nikiforos Stamatiadis
Keyword(s):  
High Speed ◽  
Potential Problem ◽  
Older Drivers ◽  
Gap Acceptance ◽  
Left Turn ◽  
Crash Data ◽  
Limited Access ◽  
Lane Changes ◽  
Elderly Drivers ◽  
Crash Rates

Older drivers, who are the fastest growing segment of the U.S. population, experience high crash rates. An analysis was performed to evaluate potential problem maneuvers that may lead to higher crash involvement. Left turns against oncoming traffic, gap acceptance for crossing non-limited-access highways, and high-speed lane changes on limited-access highways are identified as such maneuvers. Older and younger driver accident propensities are measured, using Kentucky crash data. The findings of the analysis show that older drivers are more likely to be involved in crashes related with these maneuvers compared with younger drivers; older male drivers are safer than older female drivers in left-turn crashes and gap acceptance–related crashes, and having a passenger beside the older drivers makes for a safer driving environment. Potential countermeasures aiming to reduce the accident rates of older drivers are discussed.

scholarly journals Resolving Last-Mile Connectivity Issues in Botswana Using WiMAX IEEE802

2021 ◽  
Author(s):  
Malebogo Mokeresete ◽  
Bukohwo Michael Esiefarienrhe
Keyword(s):  
Developing Countries ◽  
Rural Areas ◽  
High Speed ◽  
Simulation Method ◽  
Line Of Sight ◽  
Infrastructure Development ◽  
Ieee 802.16E ◽  
Access Technology ◽  
Regulatory Standards ◽  
Last Mile

Amongst advantages of using Worldwide Interoperability Microwave Access (WiMAX) technology at the last-mile level as access technology include an extensive range of 50 km Line of Sight (LOS), 5 to 15 km Non-Line of Sight and few infrastructure installations compared to other wireless broadband access technologies. Despite positive investments in ICT fibre infrastructure by developing countries, including Botswana, servicing end-users is subjected to high prices and marginalised. The alternative, the Wi-Fi hotspot initiative by the Botswana government, falls far as a solution for last-mile connectivity and access. This study used OPNET simulation modeller 14,5 to investigate whether Botswana’s national broadband project could adopt WiMAX IEEE 802.16e as an access technology. Several developing countries in Africa and the world use WiMAX technology at access level and gain impressive results. The rampant lack of infrastructure development and the need to provide high-speed technology has necessitated such investigation. Therefore, using the simulation method, this paper evaluates the WiMAX IEEE 802.16e/m over three subscriber locations in Botswana. The results obtained indicate that the deployment of the WiMAX IEEE 802.16e standard can solve most of the deployment issues and access at the last-mile level. Although the findings suggest that WiMAX IEEE 802.16e is more suitable for high-density areas, it could also solve rural areas’ infrastructure development challenges and provide required high-speed connectivity access. However, unlike the Wi-Fi initiative, which requires more infrastructure deployment and less on institutional and regulatory frameworks, the deployment of WiMAX IEEE802.16e requires institutional and regulatory standards.

scholarly journals Attack behaviour in naïve Gyrfalcons is modelled by the same guidance law as in Peregrines, but at a lower guidance gain

2021 ◽  
pp. jeb.238493
Author(s):  
Caroline H. Brighton ◽  
Katherine E. Chapman ◽  
Nicholas C. Fox ◽  
Graham K. Taylor
Keyword(s):  
High Speed ◽  
Angular Rate ◽  
Species Level ◽  
Line Of Sight ◽  
Proportional Navigation ◽  
Evolutionary Origins ◽  
Guidance Law ◽  
Flight Morphology ◽  
Aerial Hunting ◽  
The Individual

The aerial hunting behaviours of birds are strongly influenced by flight morphology and ecology, but little is known of how this relates to the behavioural algorithms guiding flight. Here we use GPS loggers to record the attack trajectories of captive-bred Gyrfalcons (Falco rusticolus) during their maiden flights against robotic aerial targets, which we compare to existing flight data from Peregrines (Falco peregrinus). The attack trajectories of both species are well modelled by a proportional navigation (PN) guidance law, which commands turning in proportion to the angular rate of the line-of-sight to target, at a guidance gain. However, naïve Gyrfalcons operate at significantly lower values of N than Peregrines, producing slower turning and a longer path to intercept. Gyrfalcons are less manoeuvrable than Peregrines, but physical constraint is insufficient to explain the lower values of N we found, which may reflect either the inexperience of the individual birds or ecological adaptation at the species level. For example, low values of N promote the tail-chasing behaviour that is typical of wild Gyrfalcons and which apparently serves to tire their prey in a prolonged high-speed pursuit. Likewise, during close pursuit of typical fast evasive prey, PN will be less prone to being thrown off by erratic target manoeuvres at low guidance gain. The fact that low-gain PN successfully models the maiden attack flights of Gyrfalcons suggests that this behavioural algorithm is embedded in a guidance pathway ancestral to the clade containing Gyrfalcons and Peregrines, though perhaps with much deeper evolutionary origins.

scholarly journals Braking System Automation on Cars using a Distance Sensor

2019 ◽  
Vol 7 (1) ◽  
pp. 54-65
Author(s):  
Rodi Hartono ◽  
Fajar Petrus Apris Samosir ◽  
Okta Rusdiansyah ◽  
Rizky Naufal M
Keyword(s):  
Fuzzy Logic ◽  
High Speed ◽  
Human Error ◽  
Traffic Accidents ◽  
Automation System ◽  
Security Systems ◽  
Braking System ◽  
Visual Aid ◽  
Brake Force ◽  
Driver Error

The factor of driver error in driving (human error) is one of the causes of the high number of traffic accidents in the present. To anticipate this, the discipline and concentration of the driver when driving is needed. However, when drivers have discipline and sufficient concentration of accidents can still occur. Therefore, the quality of the vehicle security system also greatly affects safety when driving. With the development of science and technology today it is very possible for humans to make security systems in vehicles. Accidents are often caused by the driver being unable to react quickly when there is a sudden blocking of objects. Especially when the driver is driving at high speed. This can be overcome by automating the braking system, so that the vehicle's speed will slow down even though the driver does not step on the brake lever. So that the possibility of an accident can be avoided. And automation is expected to be implemented in vehicles widely. In this study, designed a brake automation system using fuzzy logic by making a prototype. This prototype serves as a visual aid to evaluate the workings of the membership functions that will be used. From this evaluation it is known the value of each membership function. These values ​​are used as the main parameters in determining the Rules that will affect the output value of the brake force. With these Rules, automation of the brake system can work optimally. And it is known that the distance of the prototype car can run between other obstacle with a width of 50cm and the braking of the prototype car stops completely when the prototype is ± 5-10 cm with the obstacle in front of it. Keywords: Automation of Brake Systems, Fuzzy Logic, Distance, Speed.

scholarly journals The Effect of Low Friction in Pavement Due to Floods and High-speed Vehicles in Increasing the Number of Rescue Vehicles' Driving Accidents

2020 ◽  
Vol 6 (1) ◽  
pp. 29-38
Author(s):  
Mohammad Mehdi Khabiri ◽  
◽  
Zohrah Ghaforifard ◽  
Keyword(s):  
Natural Disasters ◽  
High Speed ◽  
Traffic Accidents ◽  
Probabilistic Method ◽  
Geometric Design ◽  
Critical Parameters ◽  
Rescue Operation ◽  
Curve Length ◽  
Speed Parameter ◽  
The Right

Background: The rescue operation is dangerous during floods when the street surface is wet and the rescue vehicles moving fast. Rural roads are known with a high percentage of run-off-the-road crashes and accidents, mostly affected by the unsuitable and inappropriate speed of the car and failure to keep a safe side distance from the highway alignment. Determining the length of the vertical curve and the stopping distance depends on the speed parameter in the geometric design. This parameter depends on the traffic flow and the vehicle driver. Materials and Methods: The calculation of distance visibility, especially in the vertical and horizontal curves, has a significant role in the geometric design of roads and the safety of roads and drivers. This study investigates changes in two critical parameters of friction surface of pavement and vehicles’ speed on the probability of accidents. In the present study, by changing the speed parameter, namely, increasing speed and decreasing friction, and reducing the distance of vision, the required vertical curve is calculated and compared with the existing curve length. Thus, when the curve length does not match the required arch length, the accident’s probability increases. Results: One of the study’s findings indicates that with a 5% decrease in the friction coefficient of the vertical curve, the probability of accident increases by about 20%. The results show that an approximately 10% increase in speed can raise the likelihood of a crash by 25% on average. Conclusion: The use of accident reduction-related strategies for rescue vehicles and ambulances will help the victims affected by natural disasters. The results showed that choosing the right speed is very important in flooded wet streets. Driving fast to speed up the relief operation not only increases the risk of traffic accidents but also slows down the relief of natural disasters. The results indicate the proper performance of the model created by the probabilistic method. Besides, this model’s use has the advantage of correctly identifying the factors affecting the increase in risk. Also, it helps to take the right measures to increase safety in the relief of natural disasters, especially floods.

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