Deceleration Values Research Articles

Analysis of Regenerative Braking Energy Utilization in KfW i9000 Electric Trains on the Palur-Yogyakarta Operation

Abstract This study explores the potential assessment. of regenerative braking energy in the operation of Electric Multiple Units (EMU) on the Yogyakarta-Palur railway line, a 65.03 km. Prompted by a noticeable increase in passenger numbers in the Yogyakarta metropolitan buffer zone, the study calls for future energy management strategies, involving regenerative braking to reduce energy consumption. Utilizing a mathematical model implemented via MATLAB Simulink, the research encompasses complex train movement scenarios, considering variables such as acceleration values of 0.558 m/s2 and 1 m/s2, and deceleration values of -0.555 m/s2 and 0.36 m/s2. Speed limitations, travel patterns, and energy profiles are rigorously examined, along with incline influences, such as tangent angles of 0.0032 degrees and 0.0017 degrees. In segments like Purwosari-Solo Jebres, electrical energy consumption is quantified at 23.02 kWh, with regenerative braking energy at 1.42 kWh; in Maguwo-Brambanan, consumption is 15.28 kWh, with regenerative energy at 2.42 kWh. The peak power requirements and regenerative braking potentials were also determined, with values such as 619.9 kW and 225.7 kW, and 1785 kW and 198.2 kW respectively. The total electrical consumption for the routes from Palur to Yogyakarta and vice versa was found to be 325.52 kWh and 276.73 kWh, with energy recovery of 31.43 kWh and 26.6 kWh, and average energy recovery ratios of 9.66% and 9.61%.

Using distributed simulations to investigate driver-pedestrian interactions and kinematic cues: Implications for automated vehicle behaviour and communication

As we move towards a future with Automated Vehicles (AVs) incorporated in the current traffic system, it is crucial to understand driver-pedestrian interaction, in order to enhance AV design and optimization. Previous research in this area, which has primarily used naturalistic observations or single-actor virtual reality simulations, has been limited by its inability to draw causal conclusions, also due to a lack of real human–human interactions. Our study addresses these limitations by employing a high-fidelity distributed simulation setup that links drivers in a motion-based simulator with pedestrians in a CAVE-based environment. This method allows for the examination of real-time and reciprocal interactions across a range of road-crossing scenarios. Using thirty-two pairs of drivers and pedestrians, we investigated how different factors, such as the presence of zebra crossings and varying time gaps of the approaching vehicle, influence driver behaviour and pedestrian crossing decisions. The effect of drivers’ control of the vehicle during such crossings (e.g., braking behaviour and lateral deviation) on pedestrians’ crossing decisions were also analysed. We found that the distribution of drivers’ average deceleration values were bimodal, where drivers either markedly yielded to pedestrians, or continued in their path, with very few instances of intermediate behaviour. We also found that pedestrian decisions were seemingly influenced by the different braking strategies adopted by the driver, with pedestrians crossing before the vehicles in response to soft and early, or late and hard braking, while late and soft braking often resulted in the vehicle passing first. We also observed a slight lateral movement of the vehicle away from pedestrians when drivers were not yielding, but more of a lateral deviation towards them when yielding. This may be because drivers subconsciously transfer their walking interaction habits to their driving behaviour, to avoid a collision with pedestrians. Finally, our results showed a stronger influence of these kinematic cues on pedestrian crossing decisions, when compared to zebra crossings. As well as highlighting the value of a novel approach for investigating vehicle–pedestrian interactions, this study illustrates how vehicle cues can assist pedestrian decisions, adding new knowledge in the development of human-like behaviour for future AVs.

Regarding the issue of the influence of factors on the braking parameters of M1 category vehicles with electric or hybrid power unit

Problem. The relevance of this work is explained by the fact that there are no works at all in the reference and normative literature on the theory and practice of forensic auto technical examination, and even more so, methodical recommendations regarding the values ​​of the braking parameters of vehicles of the M1 category with an electric power plant. Goal. The purpose of the work is to establish the factors that affect the braking parameters of M1 category vehicles with an electric or hybrid power unit. Methodology. The approaches adopted in the work to solve the set goals are based on the theory of conducting the experiment, the theory of the interaction of the pneumatic tire with the road surface, the theory of the car and the laws of theoretical mechanics. Results. On the basis of the obtained experimental data regarding the value of permanent deceleration and the time value of the increasing deceleration during emergency braking of the M1 category vehicles with an electric or hybrid power unit, the tasks will be solved necessary for conducting forensic engineering and transport examinations for specific road traffic events with the participation of M1 category vehicles with an electric or hybrid power unit. Originality. The results of the study provided an opportunity to get an idea of the influence of factors on the braking parameters of M1 category vehicles with an electric or hybrid power unit. Practical value. The obtained results can be recommended to forensic experts when writing expert opinions or expert studies.

Forced Vibration of Time-Varying Elevator Traction System

This paper proposes a theoretical model for the forced vibration of time-varying elevator traction systems caused by eccentric excitation of the traction machine. Based on the Hamilton principle and a variational principle with variable boundaries, the equations of motion and the complex boundary condition of a time-varying elevator traction system are established. A quantitative formula between the angular velocity of the traction machine, the diameter of the traction wheel, the elevator running distance and the running time is put forward. It is found that when the maximum values of acceleration and deceleration exceed 1.5 m/s², the elevator traction system may undergo resonance.

Kinetic and Kinematic Characteristics Underpinning Change of Direction Performance in Basketball: A Comparative Study Between Sexes and Tests.

Baena-Raya, A, Díez-Fernández, DM, Martínez-Rubio, C, Conceição, F, and López-Sagarra, A. Kinetic and kinematic characteristics underpinning change of direction performance in basketball: A comparative study between sexes and tests. J Strength Cond Res 38(4): e182-e188, 2024-This study (a) evaluated the sex-specific kinetic and kinematic outcomes underpinning change of direction (COD) performance, (b) compared these outcomes across 3 different COD tests, and (c) examined the sex-specific and test-specific outcome most strongly related to COD performance in basketball players. Thirty young basketball players (17 males and 13 females) competing at the national level were assessed for the modified 505 test, modified T test, and V-cut test. The Local Positioning System technology (WIMU PRO, Realtrack Systems S.L., Almería, Spain) was used to measure the maximum values of acceleration (ACC max ), deceleration (DEC max ), velocity (VEL max ), and centripetal force (CentF max ) in each COD test. Male players displayed greater ACC max , VEL max , DEC max , and CentF max outputs for each section of the 505 test, T test, and V-cut test (all p < 0.05), resulting in a faster COD performance than females across tests (all ES > -1.42; 95% CI = -3.45 to -0.57). The 505 test demanded significantly greater kinematic outputs than T test and V-cut test for both sexes ( p < 0.01). The ACC max explained ∼26-58% of the variability in COD time for males across tests ( p < 0.05) and 40% in females' modified 505-test time ( p < 0.05). Likewise, in females, DEC max explained 38% of the modified T -test time variability, whereas VEL max explained 53% in the V-cut test time (both p < 0.05). These findings suggest that (a) COD data should not be used interchangeably across sexes, (b) test specificities should be considered for designing COD training, and (c) the kinematic outcomes explaining COD performance might vary across sexes.

The Impact of Line-of-Sight and Connected Vehicle Technology on Mitigating and Preventing Crash and Near-Crash Events.

Line-of-sight (LOS) sensors developed in newer vehicles have the potential to help avoid crash and near-crash scenarios with advanced driving-assistance systems; furthermore, connected vehicle technologies (CVT) also have a promising role in advancing vehicle safety. This study used crash and near-crash events from the Second Strategic Highway Research Program Naturalistic Driving Study (SHRP2 NDS) to reconstruct crash events so that the applicable benefit of sensors in LOS systems and CVT can be compared. The benefits of CVT over LOS systems include additional reaction time before a predicted crash, as well as a lower deceleration value needed to prevent a crash. This work acts as a baseline effort to determine the potential safety benefits of CVT-enabled systems over LOS sensors alone.

Experimental studies of braking parameters of vehicles of category M2, N2, N3

Experimental studies of the braking parameters of vehicles M2, N2, N3 and KSM have been carried out. As a result of the research, new values of the steady-state deceleration of the vehicle and correction coefficients were obtained. Keywords braking parameters, steady deceleration, forensic auto technical examination

Possession or position games: What is the key in soccer?

The aims of this study were to compare the running performance of possession and position games and to describe the external load of the same position game played on pitches of different dimensions. Using a GPS system (WIMU Pro, RealTrack Systems, Almería, Spain), the running demands of 25 professional soccer players were monitored during 18 possession (without a standardized role position) and 18 positional (with a specific role position) games of 9 vs. 9 + 2 floaters. Each format was developed in small (< 60 m2 per payer), medium (60-90 m2 per player) and large (> 90 m2 per player) sizes. Position games obtained significantly lower distance covered, peak speed and player load values than possession games (all p < 0.05). However, position games obtained significantly higher values of maximal acceleration, maximal deceleration, accelerations higher than 3 m · s-2 and decelerations lower than -3 m · s-2 than possession games (all p < 0.05). Likewise, large position games obtained significantly higher values of distance covered, distance covered > 21 km · h-1, peak speed and player load than small and medium sizes. Large size also showed significantly higher values of maximal acceleration and deceleration than small size, significantly fewer accelerations and decelerations, and fewer accelerations lower than 3 m · s-2 and decelerations higher than -3 m · s-2 compared to medium and small size (all p < 0.05). Practitioners should keep in mind the use of these games and their size to modify the external load of the players during their training.

Experimental investigations of steady-state deceleration parameters of L6 category vehicles

At the moment, the authors have not been able to find updated databases that allow the expert to choose the braking parameters of vehicles of category L6, which are as close as possible to the road situation that preceded the accident, when conducting road traffic (auto-technical) examinations. Within the framework of this work, the authors investigated the nature of changes in the steady-state deceleration of vehicles. Based on the obtained results of experiments on the category of vehicles L6, the researchers have determined the data on the braking distance and the average value of deceleration during braking on different types of road surface. Keywords road transport expertise, traffic safety, deceleration, L6 vehicle category

The Use of Transition Curves in Airport Runway Rapid Exit Taxiways (RETs)

This paper describes a study result focused on the transition curves used in airport rapid exit taxiways (RETs). Such geometric elements are not currently made explicit by standards, and major international government agencies, such as the International Civil Aviation Organization and the Federal Aviation Administration, are limited to providing some layouts consisting of only constant curvature elements, although the aircrafts speed in RETs is variable. In addition to the clothoid that has unitary shape parameter “n” and the multiparameter clothoids (generalized Cornu spirals), the study analyzes the Bloss curve employment. Regarding the multiparameter clothoids, four schemes with shape parameter equal to 1.25, 1.50, 1.75, and 2.00 were considered, respectively. The proposed curves’ effectiveness was evaluated by analyzing the main geometric and kinematic variables trend, that is, curvature, transversal acceleration, lateral jerk, speed, travel time, longitudinal deceleration, and centrifugal force. To ensure the analysis effectiveness, the study layouts were designed from those used for runways codes 1‐2 and 3‐4 maintaining the main geometric elements dimensions unchanged (length of straight lines, radii of circular curves, exit angles, etc.). The kinematic variables values along the design RETs were calculated “point by point” by MATLAB software to take into account nonuniform motion regimen. The obtained results show that both the Bloss curve and the multiparameter clothoid having a shape factor equal to 2 are capable of better contribution in terms of safety and comfort. Implications in the airport construction field are related to the possibility of using lower deceleration values compared to current standards, that is, allowing higher exit speed for the same deceleration. This allows aircrafts to vacate the runway more quickly and, therefore, to increase runway capacity without taking expensive RETs repositioning.

Enhanced anti-impact resistance of polyurethane foam composites with multi-phase shear thickening fluids containing various carbon nanofillers

Polyurethane (PU) foams are commonly used as impact-absorbing materials in various applications. However, the anti-impact performance of PU foams can be improved by incorporating non-Newtonian based smart fluids in their strudture. This study enhanced a open-cell based PU foam with multi-phase shear thickening fluids (M-STFs) containing three types of carbon nanofillers (carbon nanotubes, carbon nanofibers, and their mixture). M-STFs were prepared by adding 0.5, 1.0, 1.5, and 2.0 wt% of carbon nanofillers to the STF (55 wt% SiO2) and subsequently impregnating them into the structure of PU foams. Various configurations of PU foam composites were designed and evaluated for their impact resistance performance using a low-velocity drop tower system. The rheological behavior of fabricated suspensions were characterized using a rotational two plate-based system. The chemical structure and morphology of M-STF-treated PU foams were characterized by FTIR spectroscopy and SEM, respectively. The peak deceleration values in terms of G were measured after subjecting the designed samples to impacts at three different heights of 0.1, 0.2, and 0.3 m. The results indicated that the addition of nanofillers enhaced the initial and peak viscosity of the STF, and carbon nanotube had the most significant effect. The PUF-STF/CNT(1.5) sample exhibited approximately 62.7% to 73.0% reduction at different heights in peak deceleration compared to the clean PU foam sample. Moreover, to investigate the impact of filler content, drop height, and type of fillers on the peak deceleration of M-STF-treated PU foams, a response surface methodology analysis was utilized and the model provided insight into the optimal conditions for minimizing peak deceleration. This study highlights the potential of using M-STFs to enhance the anti-impact performance of PU foams.

Student Scientific Club in Research for Road Safety

Aim: Presentation of the potential of the student scientific club for road safety in Poland. Discuss the extent to which the student scientific club in its research activities supports and implements the concepts of identifying road safety risks and submits proposals for improving its condition and related processes. Project and methods: In the research on the visibility of vulnerable traffic participants, a theoretical method – NUR threat analysis – was used to define the research problem.A research problem was formulated in the form of a question: to what extent and under what conditions does NUR visibility affect their safety? Visibility tests were conducted in real conditions after dusk. The following recording devices were used to study the movement parameters of modern means of transportation (bicycles and electric scooters): a Gopro camera, a Sony IV RX10 camera (which realizes 4D recording), a drone with a vision camera, and a Brake Tester retarder. Results: The study of the visibility of vulnerable traffic participants from the perspective of the driver presents parameters for the visibility of pedestrians and cyclists in conditions after dusk. Participants (students) in the visibility study were made aware of the issue of visibility, and therefore the safety of the traffic participant in the situation of illuminated vehicle (bicycle) and without lighting, as well as a pedestrian on the road without a reflective element. They formulated the conclusion that seeing does not mean being seen.The result of the single-track motion tests was that the Brake Tester Model LWS -2/MC retarder, after the performance test, does not provide a measurement of the single-track motion parameters. This is an important practical finding from the research, as vehicle inspection stations are equipped with this device. The acceleration and deceleration values of the bicycle and electric scooter were determined Conclusions: The research activities of the students of the scientific club in question not only make them aware of the risk factors of becoming a victim of an accident as a vulnerable traffic participant, but also allow them to deepen their knowledge, broaden their cognitive perspectives and supplement their skills through practical activities, for example, in the area of NUR visibility determinants or the characteristics of powered vehicles. The transfer of the results of the conducted research is carried out through the participation of students in seminars and scientific conferences, as well as in journalistic activities. Keywords: scientific club, vulnerable road user, education

Investigating the Effects of Load and Deceleration on Non-Pneumatic Tire Deformation and Stress during Braking

The Non-pneumatic tire (NPT) is a unique tire design that was introduced in 2005 and had the potential to replace traditional tires. Unlike conventional tires, the NPT uses flexible rods called spokes instead of air to maintain its shape. Several spoke models, such as tweel, honeycomb, and Bridgestone designs, have been developed and tested for static loads using numerical analysis. In this study, the behavior of the NPT was investigated under braking forces. The finite element method (FEM) was used to calculate load results, and the deformation of the NPT was measured with variations in load and deceleration values. Results showed that stress and deformation in the NPT increased with higher loads or deceleration values.

Dynamic and Stationary Testing of Vehicle Braking Systems

Abstract The paper deals with the dynamic and stationary testing of vehicle braking systems for a selected set of eight intercity buses in an unloaded state. In case of the dynamic test carried out on a defined test area, a decelerometer is used to record the braking deceleration of a set of vehicles, which is placed in the vehicle during the course of test. According to the methodical procedure, the vehicle is accelerated to a speed of 40 km·h-1 and subsequently braked with the maximum braking deceleration. Braking deceleration values recorded by the decelerometer were used to calculate vehicle braking. During the stationary test, a roller brake tester was used, on which the maximum braking forces on the front and rear axles of the vehicle are measured, and then, the braking of the vehicle is calculated from these values according to the methodical procedure. The calculated braking values of vehicles during the dynamic and stationary test are subsequently compared, where it is possible to observe the percentage difference of these values, which may be caused by several factors taken into account in the results of the paper.

Quintessence scalar field of Kaniadakis holographic dark energy model with statefinder analysis

This paper explores the quintessence reconstruction and statefinder perspective of Kaniadakis holographic dark energy model in a flat universe with future event horizon as an IR-cutoff. The cosmological parameters of this model were re-examined from the quintessence behavior aspect. Also we reconstruct, [Formula: see text], the potential of quintessence scalar field, which shows the best fit with joint analysis data of JLA+CC+BAO for the priors [Formula: see text], [Formula: see text]. In the [Formula: see text]–[Formula: see text] phase space, the freezing-tracker model represents our canonical scalar field. This model exhibits quintessence behavior in the statefinder ([Formula: see text]–[Formula: see text]) plane for model parameters [Formula: see text] and [Formula: see text] that are close to [Formula: see text] and [Formula: see text]. The present values of deceleration [Formula: see text], statefinder [Formula: see text], jerk [Formula: see text] and model parameters [Formula: see text] are consistent with the limits of the observational data. Using the distance modulus [Formula: see text], we also fit 580 SN Type I Union2.1 data sets to our model.

Impact-Dissipating Capacity of Fiber-Reinforced Polymer Samples, Fabricated by Fused Filament Fabrication

The use of additive manufacturing for the fabrication of sacrificial cladding is becoming increasingly popular as it facilitates the production of complex yet space-saving protective structures. Despite this, the effect of several structural parameters on their capacity to mitigate high-velocity impacts remains elusive. Toward this end, the shock-mitigating capacity of various short fiber-reinforced polymer samples was evaluated regarding impact velocity and mass (raging from 1 to 8.3 m/s and 5.5 to 7.5 Kg, respectively). Among the assessed parameters were peak force (measured to vary by up to 46.6%), max. and mean deceleration values (with max. differences documented at 29.5% and 48.2%, respectively) and cushion factor. As expected, the progressive crushing modes differed significantly across the spectrum of the tested samples. Structural failure involved the growth of inter- and intra-laminar cracks, fiber-matrix de-bonding and de-lamination, which was dependent on equivalent pore volume fraction and compressive strength. Increasing infill density led in most cases to higher peak forces during impact, as did the deposition of more solid peripheral layers, with the latter producing a superior deceleration plateau. Evaluated collectively, the results indicate that an infill density of 37% with 4 solid external (protective) layers exhibited the superior impact response among the tested samples.

Kantowski–Sachs Barrow holographic dark energy model in Saez–Ballester theory of gravitation

In this paper, we have studied a spatially homogeneous and anisotropic Kantowski–Sachs universe in the presence of Barrow Holographic Dark Energy in the background of Saez–Ballester scalar–tensor theory of gravitation. To find the exact solution of the SB field equations, we have assumed that the shear scalar is directly proportional to expansion scalar. This assumption leads to relation between metric potentials of the models. We have discussed non-interacting and interacting cosmological models. Moreover, we have discussed several cosmological parameters such as energy densities of DM and DE (ρm &ρb), deceleration (q), equation of state (ωb) and skewness (α) parameters, squared sound speed (vs2), ωb−ωb′ plane statefinders and Om-diagnostics parameters through graphical representation for both the interacting models. Also, we have observed that the current values of deceleration and EoS parameters of our constructed models are coincide with the recent observational data.

A NEW WAY TO CONTROL THE DISTRIBUTION OF BRAKING FORCES BETWEEN THE AXLES OF THE CAR

The distribution of braking forces between the axles has a significant impact on the stability of the car when braking. Over the years, dozens of authors have proposed various methods for regulating braking forces and devices for their implementation (brake force regulators - RTS). The regulation process in most of the known technical solutions was carried out by changing the ratio of the pressure of the working fluid (liquid or air) in the actuators of the brake drive of the front and rear brakes. To change the ratio of the specified pressure, the regulation of the working fluid was used, which led to the instability of the regulation characteristics and the failure of the brake system. In this article, a new method for controlling the distribution of braking forces between the axles is proposed and researched, the essence of which is to change the ratio of the total areas of the actuators of the brake drives (the areas of the pistons of the working brake cylinders). The implementation of this method of controlling the distribution of braking forces between the axles became possible due to the creation of open-type multi-piston disc brakes with two pairs of concentrically arranged brake pads. The proposed method makes it possible to increase the stability of the car not only during emergency, but also during service braking. The aim of the study is to increase the stability of the car during emergency and service braking by using a new method of controlling the distribution of braking forces between the axles by discretely changing the size of the active working areas of the working brake cylinders. To achieve this goal, the tasks of determining the value of the coefficient of distribution of the brake force on the front axle of the car with a different combination of the included working brake cylinders on the wheels and rear wheels and determining the threshold values of the car deceleration, at which it is necessary to change the ratio of the included working brake cylinders on the wheels of the front and rear axles, are solved .The results of the study showed that the use of multi-piston disc brakes on the front and rear wheels of a twoaxle vehicle makes it possible to organize the process of impulse control of the distribution of braking forces between the axles.

Experimental Study on Longitudinal Acceleration of Urban Buses and Coaches in Different Road Maneuvers.

A vehicle's longitudinal acceleration is a parameter often used for determining vehicle motion dynamics. This parameter can also be used to evaluate driver behavior and passenger comfort analysis. The paper presents the results of longitudinal acceleration tests of city buses and coaches recorded during rapid acceleration and braking maneuvers. The presented test results demonstrate that longitudinal acceleration is significantly affected by road conditions and surface type. In addition, the paper presents the values of longitudinal accelerations of city buses and coaches during their regular operation. These results were obtained on the basis of registration of vehicle traffic parameters in a continuous and long-term manner. The test results showed that the maximum deceleration values recorded during the tests of city buses and coaches in real traffic conditions were much lower than the maximum deceleration values found during sudden braking maneuvers. This proves that the tested drivers in real conditions did not have to use sudden braking. The maximum positive acceleration values recorded in acceleration maneuvers were slightly higher than the acceleration values logged during the rapid acceleration tests on the track.

Study of Loads Acting on the Load during the Sudden Braking of a Vehicle

This article presents the results of a study of the braking process in terms of assessing the longitudinal loading condition of transported cargo. The existing methods of securing cargo do not take into consideration the type of vehicle used to transport the cargo. This may result in cargo not being transported in compliance with the principles of proper cargo protection. This paper discusses the differences in maximum deceleration values achieved by different types of vehicles that are structurally suitable for freight transport. As a result of these differences in deceleration values, the values of forces acting on the transported cargo are also different. This paper presents and analyses the results of road tests that entailed the heavy braking of two vehicles structurally suitable for freight transport. One of them was a delivery vehicle, while the other was a semi-trailer truck. The experiment was carried out in six measurement series. Four of them were performed on an asphalt pavement, while the other two on a concrete pavement. One series included ten brake tests. Deceleration values registered during the tests were later used to determine the values of coefficient Cx, which were then compared with standardised values. It has been shown that failure to take into account in the selection process of cargo securing equipment, vehicle category, and type and condition of the pavement can result in cargo displacement and even traffic incidents.