scholarly journals REFINED METHOD FOR CALCULATING HEADING ANGLES OF A VEHICLE AT THE END OF BRAKING

2021 ◽  
pp. 86-95
Author(s):  
N.V. Kholshev ◽  
◽  
D.N. Konovalov ◽  
A.A. Lavrenchenko ◽  
◽  
...  
Keyword(s):  
Center Of Mass ◽  
Longitudinal Axis ◽  
Theoretical Studies ◽  
Road Accidents ◽  
Urgent Task ◽  
Common Causes ◽  
Traffic Corridor ◽  
Heading Angle ◽  
Effective Development ◽  
Safety Systems

Reducing the number of road accidents is an urgent task, the solution of which can be achieved, including by improving the design of vehicles. One of the most common causes of road accidents is the occurrence of a car skidding during braking with its subsequent exit from the traffic corridor. The effective development of new vehicle safety systems that increase its directional stability during braking and the improvement of existing systems is possible only if there are reliable methods that take into account the main parameters of the vehicle that affect its stability during braking. The currently existing methods and expressions for calculating the heading angles of a car at the end of braking have a number of assumptions that facilitate the calculations. This does not diminish their value, but slightly reduces accuracy. The purpose of this work was to clarify the methodology for calculating the permissible and actual heading angles of the vehicle at the end of braking. Within the framework of the work, theoretical studies have been carried out, based on the analysis of existing research on this topic. Based on the analysis performed, it was found that the existing methods and expressions for calculating the heading angle of a car at the end of braking do not take into account the effect of differences in the track dimensions of the front and rear axles of the car, and the center of mass of the car is conventionally assumed to be located on the longitudinal axis of the car. Evaluation of the influence of these parameters on the accuracy of calculations has not been carried out at present, there are no expressions for calculating the permissible heading angle of the vehicle at the end of braking. As a result of theoretical studies, a refined technique was obtained, including expressions for calculating the actual heading angle of the vehicle at the end of braking under various braking modes. The previously specified parameters are taken into account in the expressions obtained. An equation was derived to calculate the permissible heading angle of the car at the end of braking, taking into account the dimensions of the car, its location relative to the edge of the carriageway and the width of the lane. The refined expressions and the resulting equation that form the methodology for calculating the heading angles of the vehicle at the end of braking represent the scientific novelty of this work. To increase the efficiency of calculations according to the proposed method, a computer program has been developed. The direction of further research is to assess the adequacy and accuracy of the proposed methodology using the developed program.

Road barriers: modern solutions for improving traffic safety

2021 ◽  
pp. 43-48
Author(s):  
Keyword(s):  
Traffic Safety ◽  
Traffic Accident ◽  
Preventive Measures ◽  
Mechanical Damage ◽  
Road Accidents ◽  
Road Users ◽  
Urgent Task ◽  
The Moment ◽  
Energy Absorbing ◽  
The Impact

Improving the system of preventive measures aimed at reducing the severity of the consequences of road accidents is an urgent task. Road deaths are constantly increasing and there is a need for a comprehensive approach to creating safe road conditions. The purpose of this study is to analyze the promising designs of road barriers designed to prevent uncontrolled exit of vehicles from the roadway of the highway and to develop the design of energy-absorbing fencing. Barrier barriers must not only be safe for road users, but must also ensure their safety, as well as preserve the elements after hitting the fence. Analytical studies have shown that in order to reduce mechanical damage to vehicles and reduce the severity of injuries to the driver and passengers, it is necessary to develop a road fence design that allows you to extinguish the impact energy at the moment of contact between the car and the fence. Keywords: fencing, barrier, safety, traffic accident

scholarly journals Investigation of the relationship between theoretical and actual turning radii of a tracked vehicle using mathematical modeling

2020 ◽  
Vol 1 (4) ◽  
pp. 80-91
Author(s):  
A.A. Stadukhin ◽  
Keyword(s):  
Center Of Mass ◽  
Weight Ratio ◽  
Traction Force ◽  
Plane Motion ◽  
Practical Significance ◽  
Tracked Vehicle ◽  
Literary Sources ◽  
Active Safety Systems ◽  
Turning Radius ◽  
Safety Systems

Introduction. Determination of the traction force and power required in a turn by a tracked ve-hicle is based on analytical dependencies given in classical literary sources. In this case, the de-pendence of the theoretical and actual turning radius is usually not described accurately enough. Subject of study. A study of the dependence of the theoretical and actual turning radius and the influence of the parameters of the undercarriage of the tracked vehicle, the characteristics of the support base and the mode of movement on it was made. Methodology and methods. The study was carried out using a specially developed stationary rotation tracked vehicle (TV) model, which differs by taking into account the redistribution of nor-mal reactions and implementation, allowing one to quickly carry out multifactorial experiments. The rotation of the TV in the model is described as a plane motion of a rigid body. In contrast to the classical approaches, the model allows one to study the rotation of the TV at a speed close to the critical drift. Results and scientific novelty. During computational experiments, the parameters of the chassis of the TV, the properties of the support base, as well as the speed of movement and the actual turn-ing radius were varied. It was found that the classical dependences of the actual and theoretical turning radius need to be refined when driving at a speed close to the critical drift, while the form of the dependence is determined by the height of the center of mass of the TV. Practical significance. These features should be taken into account both when assessing the speed of the vehicle and determining the required thrust-to-weight ratio, and when working on the development of active safety systems for tracked vehicles.

scholarly journals Swimming Turned on Its Head: Stability and Maneuverability of the Shrimpfish (Aeoliscus punctulatus)

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
F E Fish ◽  
R Holzman
Keyword(s):  
Cross Sections ◽  
Swimming Performance ◽  
Center Of Mass ◽  
Leading Edge ◽  
Longitudinal Axis ◽  
The Body ◽  
Maximum Speed ◽  
Vertical Orientation ◽  
Neutrally Buoyant ◽  
Orientation Modification

Synopsis The typical orientation of a neutrally buoyant fish is with the venter down and the head pointed anteriorly with a horizontally oriented body. However, various advanced teleosts will reorient the body vertically for feeding, concealment, or prehension. The shrimpfish (Aeoliscus punctulatus) maintains a vertical orientation with the head pointed downward. This posture is maintained by use of the beating fins as the position of the center of buoyancy nearly corresponds to the center of mass. The shrimpfish swims with dorsum of the body moving anteriorly. The cross-sections of the body have a fusiform design with a rounded leading edge at the dorsum and tapering trailing edge at the venter. The median fins (dorsal, caudal, anal) are positioned along the venter of the body and are beat or used as a passive rudder to effect movement of the body in concert with active movements of pectoral fins. Burst swimming and turning maneuvers by yawing were recorded at 500 frames/s. The maximum burst speed was 2.3 body lengths/s, but when measured with respect to the body orientation, the maximum speed was 14.1 body depths/s. The maximum turning rate by yawing about the longitudinal axis was 957.5 degrees/s. Such swimming performance is in line with fishes with a typical orientation. Modification of the design of the body and position of the fins allows the shrimpfish to effectively swim in the head-down orientation.

scholarly journals DETERMINATION OF VIBRATION POWER OF VIBRATION SOURCES OF SPINDLE UNITS OF METAL CUTTING MACHINES

2021 ◽  
Vol 23 (3) ◽  
pp. 55-61
Author(s):  
A.F. Denisenko ◽  
◽  
V.V. Mikhailov ◽  
Keyword(s):  
Metal Cutting ◽  
Center Of Mass ◽  
Spindle Assembly ◽  
Vibration Field ◽  
Spindle Unit ◽  
Urgent Task ◽  
Parametric Reliability ◽  
Calculated Model ◽  
Spindle Assemblies

Monitoring the state of spindle assemblies of modern metal-cutting machines using CIP methods implies the possibility of installing control sensors in places with maximum vibration information content. In this regard, the assessment of the informativeness of the vibration field of the spindle assembly, which can be carried out in advance, taking into account the design features, geometric and dimensional characteristics, is an urgent task. Based on the energy approach, using the example of the spindle assembly of a universal lathe, a computational model is proposed, built along the median planes of the walls. On the basis of the calculated model, the equations of the energy balance were compiled taking into account the conditions for the transfer of vibration power between the walls of the housing. The method for determining the vibration power of the main sources in the spindle assemblies is given: a spindle with residual unbalance, a drive gear and bearings. It has been established that the most significant factors determining the vibration power introduced into the spindle unit housing are the operation of the bearings, the weight of the spindle and the location of its center of mass. The result obtained makes it possible to detect incipient defects in the bearings, which, as practice shows, are the defining elements of the parametric reliability of spindle assemblies. The resulting model of the vibration field can be used to determine the reference values of vibration velocities that are formed from sources in the absence of defects.

Substantiation of the influence of changes in the coefficient of axle distribution of braking force on the handling of a passenger car

2022 ◽  
Vol 14 (2) ◽  
pp. 72-79
Author(s):  
Alexander Nazarov ◽  
◽  
Vitalii Kashkanov ◽  
Roman Gumenyuk ◽  
Evgenui Kotik ◽  
...  
Keyword(s):  
Center Of Mass ◽  
Longitudinal Axis ◽  
Physical Characteristics ◽  
Steering Wheel ◽  
Braking System ◽  
Braking Force ◽  
Instantaneous Center ◽  
Braking Process ◽  
Electronic Tracking ◽  
New Algorithms

The article considers the change of the radius of the instantaneous center of rotation of a car moving along a curved trajectory during braking, taking into account the lateral input of the wheels of both axles of cars, both equipped with electronic tracking systems and not equipped with such. A criterion for assessing the controllability of cars moving on a curved trajectory in a braked state, by comparing the ratio of the current speed of the car to the longitudinal base with the ratio of the coefficients of lateral tire input to the product of the longitudinal base of the car, mass and cosines. It is established that the radius of instantaneous rotation of the longitudinal axis of the car moving along a curved trajectory during braking depends on the speed of the center of mass of the car, the coefficient of axle distribution of braking force, physical characteristics of applied tires, steering wheel angle and design and weight parameters. As a result, it allows you to set controllability. The authors obtained dependences that will create new algorithms for the operation of modern electronic control systems for stabilizing the longitudinal axis of a braked car, taking into account the speed of the car, its design and weight characteristics, the main characteristics of its braking system (coefficient of axle braking force distribution), physical characteristics used tires on wheels and connect them to the angles of the steered wheels, controlling the deviation of the longitudinal axis, which allows the driver to maintain the possibility of quite sharp maneuvers directly in the braking process, moving along a curved trajectory.

scholarly journals Evaluation of a Fatigue Detector Using Eye Closure-Associated Indicators Acquired from Truck Drivers in a Simulator Study

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6449
Author(s):  
Łukasz Dziuda ◽  
Paulina Baran ◽  
Piotr Zieliński ◽  
Krzysztof Murawski ◽  
Mariusz Dziwosz ◽  
...  
Keyword(s):  
Subjective Assessment ◽  
Truck Drivers ◽  
Road Accidents ◽  
Experimental Conditions ◽  
Subjective Fatigue ◽  
Closure Duration ◽  
Common Causes ◽  
The Individual ◽  
Eye Closure ◽  
The Relationship

This paper presents a camera-based prototype sensor for detecting fatigue and drowsiness in drivers, which are common causes of road accidents. The evaluation of the detector operation involved eight professional truck drivers, who drove the truck simulator twice—i.e., when they were rested and drowsy. The Fatigue Symptoms Scales (FSS) questionnaire was used to assess subjectively perceived levels of fatigue, whereas the percentage of eye closure time (PERCLOS), eye closure duration (ECD), and frequency of eye closure (FEC) were selected as eye closure-associated fatigue indicators, determined from the images of drivers’ faces captured by the sensor. Three alternative models for subjective fatigue were used to analyse the relationship between the raw score of the FSS questionnaire, and the eye closure-associated indicators were estimated. The results revealed that, in relation to the subjective assessment of fatigue, PERCLOS is a significant predictor of the changes observed in individual subjects during the performance of tasks, while ECD reflects the individual differences in subjective fatigue occurred both between drivers and in individual drivers between the ‘rested’ and ‘drowsy’ experimental conditions well. No relationship between the FEC index and the FSS state scale was found.

scholarly journals Developing Intelligent Child Protection and Security Systems

2020 ◽  
pp. 63-66
Keyword(s):  
Child Protection ◽  
Computational Time ◽  
Raspberry Pi ◽  
Prototype Model ◽  
Main Concern ◽  
Road Accidents ◽  
Person Identification ◽  
Security Systems ◽  
Safety Measures ◽  
Safety Systems

In present time, the security and safety aspect of a school going children is of main concern and paramount importance. In India, many children are found to be missing and yield to road accidents because of lack of preventive safety measures. Parents are always concerned about their children during commute. This project proposes an Raspberry pi based intelligent solution to assist parents in real time to track their children location. In order to track the location and find the identity of the child a AI thinker and camera is used in the proposed system. The system uses Raspberry pi as main microcontroller. The project also proposes safety systems such as person identification, Geofacing and automatically ON and OFF system using thumb impression. The working prototype model of the developed system exhibits good accuracy with reduced computational time. By incorporating all those above features, we can assure the safety and security of every school children.

scholarly journals On board Driver Monitoring System with Safety Enhanced Brake System

2019 ◽  
Vol 8 (6S3) ◽  
pp. 1844-1849
Keyword(s):  
Research Work ◽  
Health Condition ◽  
Steering Wheel ◽  
Active Safety ◽  
Road Accidents ◽  
Emergency Situations ◽  
Compression Stroke ◽  
Safety Features ◽  
Safety Systems ◽  
Additional Safety

Recent automobile vehicles require additional safety features to enhance the active safety. Due to lack of safety systems in vehicles road accidents are on the rise. The major cause of collision far 80% of accidents is drivers fault as cited by the ministry of road accidents of India. The current research work is carried out to analyze the fault of the driver and to measures the health condition of the driver by placing throb sensor and temperature sensor in steering wheel so as to slow down the vehicle by using Jake brake during abnormal health issue. The proposed systems were analyzed for different category of the condition of driver to improve the safety system technology. When triggered the exhaust valve is opened after the compression stroke enable to escape of compressed air from the cylinders to slowdown the vehicle which prevents the accidents in emergency situations.

scholarly journals Ricostruzione della dinamica degli incidenti stradali. L'ambito giuridico, la strada, il conducente e il veicolo

2011 ◽  
Keyword(s):  
Risk Factors ◽  
Forensic Medicine ◽  
Legal Aspect ◽  
Reaction Times ◽  
X Rays ◽  
Road Accidents ◽  
The Road ◽  
The Third ◽  
Safety Systems

The third and last instalment of the Firenze University Press work devoted to the reconstruction of road accidents, this book is an important complement to the two previous volumes by Dario Vangi and Virginio Rivano. Consisting of original contributions written by experts in each individual sector, the work explores the legal aspect of road accidents, consultancy and the rules of behaviour and then x-rays all the aspects relating to the road (from risk factors to containment devices), the driver (from reaction times to forensic medicine) and, finally, the vehicle (from safety systems to causes of fire and techniques of repair and estimates).

Control and Estimation of Posture During Quiet Stance Depends on Multijoint Coordination

2007 ◽  
Vol 97 (4) ◽  
pp. 3024-3035 ◽  
Author(s):  
Wei-Li Hsu ◽  
John P. Scholz ◽  
Gregor Schöner ◽  
John J. Jeka ◽  
Tim Kiemel
Keyword(s):  
Control Strategy ◽  
Center Of Mass ◽  
Longitudinal Axis ◽  
The Body ◽  
Uncontrolled Manifold ◽  
Quiet Standing ◽  
Quiet Stance ◽  
Multijoint Coordination ◽  
The Stability ◽  
Head Positions

This study tested the hypotheses that all major joints along the longitudinal axis of the body are equally active during quiet standing and that their motions are coordinated to stabilize the spatial positions of the center of mass (CM) and head. Analyses of the effect of joint configuration variance on the stability of the CM and head positions were performed using the uncontrolled manifold (UCM) approach. Subjects stood quietly with arms folded across their chests for three 5-min trials each with and without vision. The UCM analysis revealed that the six joints examined were coordinated such that their combined variance had minimal effect on the CM and head positions. Removing vision led to a structuring of the resulting increased joint variance such that little of the increase affected stability of the CM and head positions. The results reveal a control strategy involving coordinated variations of most major joints to stabilize variables important to postural control during quiet stance.

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