Lateral Speed Research Articles

Detection of pedestrian crossing road: A study on pedestrian pose recognition

Detection of pedestrian crossing road is the objective of this work. The model incorporates the pedestrian pose recognition and lateral speed, motion direction and spatial layout of the environment. Pedestrian poses are recognized according to the spatial body language ratio. The center of mass of the body relative to its width and height is used to define the pedestrian pose. Motion trajectory is obtained by using point tracking on the centroid of detected human region, and then estimated velocity is determined. Spatial layout is determined by the distance of the pedestrian to the road lane boundary. These models will be then hierarchically separated according to their action (walking, starting, bending and stopping). In order to classify the pedestrian crossing road, a walking human model is proposed. A walking human is defined by ratio of the centroid location from the ground plane divided by the height of bounding box that should satisfy a constraint. The proposed algorithms are evaluated using publicly available datasets and our pedestrian walking dataset. The performance result shows that the correct pedestrian crossing road classification is 98.10%.

A Computationally Efficient Implementation of Nonzero-Speed Transient Green Functions for Zero-Speed Nonlinear Seakeeping Problems

The proposed methodology is a time-domain panel method where the transient Green functions (GFs) used for the estimation and implementation of the free-surface effects on the vessel's motions are estimated assuming constant low lateral speed, instead of the common practice zero-speed influence functions. The main difference between the proposed method and standard practice lies in the use of the proposed scheme on a typical zero-speed problem, as the solution scheme is conditioned to the mean drift velocity instead of zero-speed. Furthermore, in this way, a significant improvement in accuracy accompanied by a large reduction in computational times is also achieved. The low lateral-speed GFs are computed for a speed similar to the one that the vessel is expected to drift. Estimation of this speed can be initially based on model tests or by means of an iterative process where we start the computations with the zero-speed GFs and adjust the latter's input speed according to the calculated drift speed until convergence is obtained. As a representative case study, we apply this method for the simulation of seakeeping behavior of a cruise ship in extreme dead ship conditions. For the validation of the proposed methodology, the first- and second-order motions, i.e., heave, roll, and the drift velocity, respectively, as well as lateral accelerations of the vessel were investigated for two cases of severe beam seas further combined with a constant strong wind load. The results were compared against experimental model tests.

Sowing performance by a metering mechanism of continuous flow in different slope conditions

One of the reasons for the success of a productive culture is the correct sowing. Therefore, the seeds must be properly dosed, deposited and not damaged by the metering mechanism of the seed drill. So, the aim of this study was to evaluate in a simulator the sorghum seed deposition by a metering mechanism with continuous flow in different conditions of slope and sowing speed, and evaluate the quality of the deposited seeds assessing mechanical damage and germination. The experiment was carried out at the College of Agricultural Sciences, UNESP in Botucatu-SP, being used a simulator equipped with seed metering mechanism of helical channelled rotor type. The experimental design was randomized in a 3 x 2 factorial arrangement with six replications. The factors were three lateral slopes drill, 3%, 8% and 16%, and two sowing speed, 4 and 10 km h-1. For the damage and germination variables we added a control treatment whose seeds were evaluated without being distributed by the metering mechanism. The results indicate that increasing the lateral slope and working speed reduce the rate of seed deposition. The metering mechanism provides mechanical damage and contributes to the reduction of seed germination.

Velocity gradients in spatially resolved laser Doppler flowmetry and dynamic light scattering with confocal and coherence gating.

Dynamic light scattering (DLS) is widely used to characterize diffusive motion to obtain precise information on colloidal suspensions by calculating the autocorrelation function of the signal from a heterodyne optical system. DLS can also be used to determine the flow velocity field in systems that exhibit mass transport by incorporating the effects of the deterministic motion of scatterers on the autocorrelation function, a technique commonly known as laser Doppler flowmetry. DLS measurements can be localized with confocal and coherence gating techniques such as confocal microscopy and optical coherence tomography, thereby enabling the determination of the spatially resolved velocity field in three dimensions. It has been thought that spatially resolved DLS can determine the axial velocity as well as the lateral speed in a single measurement. We demonstrate, however, that gradients in the axial velocity of scatterers exert a fundamental influence on the autocorrelation function even in well-behaved, nonturbulent flow. By obtaining the explicit functional relation between axial-velocity gradients and the autocorrelation function, we show that the velocity field and its derivatives are intimately related and their contributions cannot be separated. Therefore, a single DLS measurement cannot univocally determine the velocity field. Our extended theoretical model was found to be in good agreement with experimental measurements.

Bifurcation and factors influence analysis on self-excited vibration of tire tread

The purpose behind this work is to discuss dynamic stability when self-excited vibration occurs on tire tread. First of all, a suspension-tire-tread model has been built for simulation, and the result shows the existence of self-excited vibration on tire tread under particular conditions. A six-component test of the wheel indicates that self-excited vibration often takes place on tire tread when the vehicle travels straightaway at high speed. Then, through bifurcation analysis of tire tread, we found that the speed of the vehicle and slip angle of the wheel play significant roles in vibration generation. Within the lateral speed component caused by the tiny slip angle, equivalent damping of system turns to negative and thus provides enough energy to be consumed by obstructions. In order to investigate the influence of this self-excited vibration on the system, the system model has been simulated with different parameters, such as vehicle speed, vertical load, and tire pressure. The result explains different wear characteristics from the driven wheel to the driving wheel, which provides the basis of polygonal wear calculation.

Railway track irregularity and curvature estimation using doppler LIDAR fiber optics

The application of Doppler-based LIght Detection and Ranging (LIDAR) technology for determining track curvature and lateral irregularities, including alignment and gage variation, are investigated. The proposed method uses track measurements by two low-elevation, slightly tilted LIDAR sensors nominally pointed at the rail gage face on each track. The Doppler LIDAR lenses are installed with a slight forward angle to measure track speed in both longitudinal and lateral directions. The lateral speed measurements are processed for assessing the track gage and alignment variations, using a method that is based on the frequency bandwidth dissimilarities between the vehicle speed and track geometry irregularity. Using the results from an extensive series of tests with a body-mounted Doppler LIDAR system on-board a track geometry measurement railcar, the study indicates a close match between the LIDAR measurements and those made with existing sensors on-board the railcar. The field testing conducted during this study indicates that LIDAR sensors could provide a reliable, non-contact track monitoring instrument for field use in various weather and track conditions, potentially in a semi-autonomous or autonomous manner.

An analysis of error propagation in AERMOD lateral dispersion using Round Hill II and Uttenweiller experiments in reduced averaging times

ABSTRACTDispersion modelling was proved by researchers that most part of the models, including the regulatory models recommended by the Environmental Protection Agency of the United States (AERMOD and CALPUFF), do not have the ability to predict under complex situations. This article presents a novel evaluation of the propagation of errors in lateral dispersion coefficient of AERMOD with emphasis on estimate of average times under 10 min. The sources of uncertainty evaluated were parameterizations of lateral dispersion (), standard deviation of lateral wind speed () and processing of obstacle effect. The model’s performance was tested in two field tracer experiments: Round Hill II and Uttenweiller. The results show that error propagation from the estimate of directly affects the determination of , especially in Round Hill II experiment conditions. After average times are reduced, errors arise in the parameterization of , even after observation assimilations of , exposing errors on Lagrangian Time Scale parameterization. The assessment of the model in the presence of obstacles shows that the implementation of a plume rise model enhancement algorithm can improve the performance of the AERMOD model. However, these improvements are small when the obstacles have a complex geometry, such as Uttenweiller.

ACCURACY AND QUICKNESS CRITERION-BASED DRIVING SKILL METRIC FOR HUMAN ADAPTIVE MECHATRONICS SYSTEM

Previous studies on driving skill algorithm have combined tracking error and time related variables into algorithm formulation. This method however does not include a car orientation and lateral speed information as an integral part of the algorithm. Two new variables are introduced into the algorithm structure, namely, orientation angle and lateral speed. Nine participants were carefully recruited for a driving test to validate the algorithm. A simulated driving environment was specifically devised for this experiment. A driving track used in this experiment was segmented into five different severities for data analysis. Two fundamental goals have led to the collection and subsequent analysis of the data. The first is analysing the variables in relation to the driving task. The second involves data analysis being further extended into analysing the algorithm performance over estimating the driving skill index. The results reveal that the proposed variables are well correlated with the driving task, and improvement in algorithm performance is found to be almost double compared to the previous algorithm.

EFFECT OF ROAD SURFACE DEFORMATIONS ON LATERAL LANE UTILIZATION AND LONGITUDINAL DRIVING BEHAVIOURS

Various road surface deformations generally occur on urban and rural roads due to infrastructure, superstructure deficiencies and excessive heavy vehicle loads. In addition to driver-based errors, many accidents happen due to these mentioned surface deformations. This study aims to present lateral lane utilization and longitudinal driving behaviours on a two-lane deformed road. The effect of deformation on the tendency of drivers’ lane selection, lane utilization, and the movement in traffic flow will also be determined. For this purpose, parameters such as lateral position, speed, acceleration/deceleration and location data of vehicles travelling through four different deformation zones on a two-lane road in Izmir (Turkey), were collected. Based on the fact that in ideal conditions, distribution of lateral positions of vehicles in a lane is similar to normal distribution. The collected data was evaluated with chi-square (χ2) goodness of fit test to see if they are fit to normal distribution or not. This study concluded that if a deformation zone has wider area and less depth, it will be less effective on lateral lane utilization of vehicles. It was also obtained from the results that variation in other parameters such as deformation type, depth and height are associated with the lateral lane utilization of drivers. Additionally, the drivers’ characteristics such as perception and aggressiveness are seen as the most important factors influencing the longitudinal vehicle behaviours while passing through the deformation zones.

A new algorithm to maintain lateral stabilization during the running gait of a quadruped robot

This paper presents a new uncoupled controller (based on a Kinetic Momentum Management Algorithm, KMMA) which allows a quadrupedal robot, whose operation is simple and fast, to run using a symmetrical gait patterns in a wide variety of scenarios. It consists of two tasks: calculating the lateral position and speed of the fore swinging leg when it next makes contact with the ground; and controlling the roll angle by mean of inertia forces using the stance legs.The KMMA provides the benefits of modulation and the synchronization typically presented in CPG (Central Pattern Generation) models. Furthermore, it is able to maintain the locomotion parameters (such as stroke frequency of gait pattern) when the robot runs in a highly disturbed environment, thus resulting in a lower energy consumption. Additionally, the uncoupled scheme of the leg makes the operation computationally cheap, thus avoiding the use of a Virtual Actuator Control or a Hybrid Zero Dynamics.The performance of the KMMA has been verified by means of co-simulation (using ADAMS and MATLAB) with a highly realistic model of a quadruped robot with uncoupled legs. The performance of the algorithm has been tested in different situations in which the following variables have been varied: frontal velocity, turning ratio, payload, external disturbances and terrain slope. Successful results in terms of stability, energy efficiency, and adaptability to a complex locomotion environment have been obtained.

Using Commercial GPS Action Cameras for Gathering Naturalistic Cycling Data

Naturalistic cycling studies can be performed by making instrumented bicycles available to participants, or by having mobile equipment added by the participants themselves to their own bicycles. This paper describes how participants’ bicycles can be equipped with a commercially available, small and unobtrusive action camera to gather naturalistic cycling data. Lateral position, swerving and speed were analysed using video and GPS to assess cycling behaviour of older cyclists, and to assess the influence of different types of cycling infrastructure. The applied method gathered insights in possible interventions in a cost efficient way, inconspicuously, and quickly, compared with instrumented bicycles. Also, several bicycles can be instrumented at the same time with as only limitation the number of cameras available.

Assessing drivers’ visual-motor coordination using eye tracking, GNSS and GIS: a spatial turn in driving psychology

Vehicle-driving in real traffic can be considered as a human-machine system involving not only the attribute of the vehicle movement but also the human visual perception, cognition and motion of the driver. The study of driving behaviours, therefore, would integrate information related to driver psychology, vehicle dynamics and road information in order to tackle research questions concerning driving safety. This paper describes a conceptual framework and an integrated GIS data model of a visual-motor coordination model (VMCM) to investigate drivers’ driving behaviour via the combination of vision tracking and vehicle positioning. The eye tracker recorded eye fixations and duration on video images to exhibit the driver’s visual search pattern and the traffic scenes. Real-time kinematic (RTK) post-processing of multi-GNSS (global navigation satellite system) tracking generated the vehicle movement trajectory at centimeter-level accuracy, which encompasses precise lateral positioning and speed control parameters of driving behaviours. The eye fixation data were then geocoded and linked to the vehicle movement trajectory to represent the VMCM on the GIS platform. An implementation prototype of the framework and the VMCM for a study of older drivers is presented in this paper. The spatial-temporal visualisation and statistical analysis based on the VMCM data-set allow for a greater insight into the inherent variability of older drivers’ visual search and motor behaviours. The research framework has demonstrated a discriminant and ecologically valid approach in driving behaviour assessment, which can also be used in studies for other cohort populations with modified driving scenarios or experiment designs.

The Dimensional Model of Driver Demand: Visual-Manual Tasks

Many metrics have been used in an attempt to predict the effects of secondary tasks on driving behavior. Such metrics often give rise to seemingly paradoxical results, with one metric suggesting increased demand and another metric suggesting decreased demand for the same task. For example, for some tasks, drivers maintain their lane well yet detect events relatively poorly. For other tasks, drivers maintain their lane relatively poorly yet detect events relatively well. These seeming paradoxes are not time-accuracy trade-offs or experimental artifacts, because for other tasks, drivers do both well. The paradoxes are resolved if demand is modeled in two orthogonal dimensions rather than a single driver workload dimension. Principal components analysis (PCA) was applied to the published data from four simulator, track, and open road studies of visual-manual secondary task effects on driving. PCA reduced the task metrics to two underlying orthogonal components (hereafter, dimensions) which were consistent across studies, herein designated as physical and cognitive demand. Physical demand is associated with lateral and longitudinal performance (lane crossings, standard deviation of lateral position and speed), with correlated surrogate metrics of task time, step count, total glance time, number of glances, and subjective workload. Cognitive demand is associated with event detection (RT and miss rate), with correlated surrogate metrics of mean single glance time, long single glances, speed reduction, and task errors. The Dimensional Model of Driver Demand allows for a common simplified understanding of all these measures of visual-manual secondary task effects on performance. Language: en

Generation of a North/South Magnetic Field Component from Variations in the Photospheric Magnetic Field

We address the problem of calculating the transverse magnetic field in the solar wind outside of the hypothetical sphere called the source surface where the solar wind originates. This calculation must overcome a widely used fundamental assumption about the source surface -- the field is normally required to purely radial at the source surface. Our model rests on the fact that a change in the radial field strength at the source surface is a change in the field line density. Surrounding field lines must move laterally in order to accommodate this field line density change. As the outward wind velocity drags field lines past the source surface this lateral component of motion produces a tilt implying there is a transverse component to the field. An analytic method of calculating the lateral translation speed of the field lines is developed. We apply the technique to an interval of approximately two Carrington rotations at the beginning of 2011 using 2-h averages of data from the Helioseismic Magnetic Imager instrument on the Solar Dynamics Observatory spacecraft. We find that the value of the transverse magnetic field is dominated on a global scale by the effects of high latitude concentrations of field lines being buffetted by supergranular motions.

Three-dimensional stopping sight distance control on passing lanes of divided highways

Stopping Sight Distance control of passing lanes of divided highways represents currently a discussion point among researchers. A 3-D approach to address the issue is accepted as the overall solution to the problem by both researchers and contemporary design policies. This paper aims to contribute to the problem by presenting a sound and practical design solution to it with an analytic and a design values based format. The solution approach consists of both a realistic description of the 3-D highway configuration and a 3-D vehicle kinematics calculation of the stopping maneuver along the vehicle’s actual path. A SSD control method, previously developed by the authors’, that relates concurrently the 3D configuration of a roadway to the kinematics of a vehicle moving along the actual roadway path, is applied, as a tool for the assessment of critical design parameters directly related to SSD adequacy. A rather comfortable alignment case consisting of a left curved divided highway overlapped with crest vertical curve parameters for numerous horizontal—vertical arrangements is examined, where an extensive area of SSD inadequacy during emergency braking procedure is reported. The authors propose that the optimal solution to achieve SSD adequacy on left curved divided highways is to increase object height. This would preserve design consistency as well as driver expectations, by avoiding the need for lateral widening or site-specific speed limits. More specifically the object height is suggested to be equivalent to the driver’s height of 1.08 m (AASHTO 2011). This would require additional stop lights on those vehicles whose stop lights are currently below this level. Although such a requirement regarding the current vehicle fleet is not feasible, vehicle industries as well as road design guidelines should address this issue in the near future.

Evaluation of Fluctuating Speed and Lateral Movement of Vehicles: Comparison Between Mixed Traffic and Homogeneous Traffic

Urban roads in developing countries become congested more often because of the substantial lateral movement of vehicles and fluctuations in speed. Popular microscopic models such as car-following and lane-changing models are not suitable for the analysis of such traffic conditions unless some modifications accounting for heterogeneity are included. However, there seems to be an underlying mechanism behind the fluctuations that needs to be investigated thoroughly. The Hurst exponent concept of chaos theory was used to identify the hidden trends in vehicular movement. Real-life trajectory data from an urban arterial in Chennai, India, were analyzed and then compared with a homogeneous data set in the United States. The Hurst exponent for mixed traffic was found to be significantly less than that for the homogeneous data; this finding indicated the strong trends of lateral movement and speed in homogeneous traffic. The variation of Hurst exponents with vehicle type and average lateral positions was explored in mixed traffic. Results from this study will help modelers propose better microscopic simulation models accounting for the fluctuations in speed and lateral movement.

Dynamic Analysis of a Micro Drilling System by the Modified Transfer Matrix Method

Normally, breakage is the main cause of failure of a micro drilling system, of which coupling effect of lateral and torsional displacements plays the most important role. This research developed a modified transfer matrix method to investigate the dynamics of a micro drilling system focusing on displacements induced by not only lateral, shear, torsional deformations, but also the coupling effect between lateral and torsional vibrations. The micro drilling system is modeled as pre-twisted rotating Timoshenko beam elements with a continuous-system concept. Each element includes components of linear bearings, axial drilling force, gyroscopic moments, and eccentricity. The overall transfer matrix of the system is developed to determine the state vector of the system including displacements and forces. Finally, a numerical example was presented, where the lateral and torsional displacements and critical speed of the micro drilling system at the micro drill’s tip were presented.

Label-free 3D analysis of biological tissue with micron spatial and 240k mass resolution using a new SIMS hybrid mass analyser

Event Abstract Back to Event Label-free 3D analysis of biological tissue with micron spatial and 240k mass resolution using a new SIMS hybrid mass analyser Alexander Pirkl1, Rudolf Möllers1, Ewald Niehuis1, Melissa K. Passarelli2, Alexander Makarov3, Stevan Horning3 and Ian S. Gilmore2 1 ION-TOF GmbH, Germany 2 National Physics Laboratory, United Kingdom 3 Thermo Fisher Scientific, Germany Introduction: Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is an established, highly sensitive analytical technique for mass spectrometry (MS) imaging applications with a lateral resolution below 100 nm. Monitoring the uptake of nanoparticles, drugs or other chemicals into cells are only a few examples for the application of this label-free chemical analysis technique. Chemical information is obtained by bombarding the surface with a focused primary ion beam and analysing the generated secondary ions in a TOF mass analyzer. However in complex biological samples identification of unknown compounds can be hampered by mass interferences and a high number of possible candidates for a single mass peak. In order to overcome these limitations, the 3D nanoSIMS project[1] is developing a revolutionary new SIMS instrument that combines the high lateral resolution and speed associated with TOF-SIMS with the high mass resolution and high mass accuracy of an orbital trapping mass analyser. The instrument is equipped with a newly developed gas cluster ion beam column allowing a lateral resolution down to the micron level. First results obtained from different biomaterials are presented here. Materials and Methods: Amiodarone-dosed NR8383 cells and a native coronal mouse brain section were analysed using either a 20 keV argon gas or a bismuth cluster primary ion beam. For MS of the generated secondary ions a new hybrid SIMS instrument was utilized, featuring a hybrid mass analyser that combines a fast TOF analyser (TOFSIMS.5, ION-TOF GmbH, Münster, Germany) with an orbital trapping analyser (QExactiveTM HF[2], Thermo Scientific, Bremen, Germany). Results and Discussion: Fig. 1: TOF-SIMS image showing the uptake of the drug amiodarone into a single macrophage[3]. The high lateral resolution TOF-SIMS image in Fig. 1 shows the sub-cellular distribution of iodine, a moiety of the drug amiodarone (green) with respect to the nucleus of the cell (red). First gas cluster OrbitrapTM SIMS images from mouse brain sections demonstrate the simultaneous localization and identification of various compounds. On tissue, the high mass resolution (FWHM of 240 000 at m/z 200) was used to identify lipids and metabolites with sub-ppm mass accuracy. Identification of numerous lipid signals at the single cell level could be easily performed using exact mass measurement and comparison with databases. Additionally ions were selectively fragmented by tandem MS (MS/MS) in order to confirm chemical structure or help on assignment of unknown signals. Conclusion: With this unique instrument numerous applications in the field of biomaterials can be studied, including interactions between tissue and biomaterials and process control in fabrication. Laterally resolved, label-free, and non-targeted imaging of biomaterials at micron resolution is now possible.

Satisficing Curve Negotiation: Explaining Drivers’ Situated Lateral Position Variability

Abstract: Drivers exhibit a range of lateral positions that depend on their location down the road in relationship to the curves. For example, within a curve the range is narrower and biased towards the inner road edge compared to straight sections where it is more centralized and wider. The question is what shapes the swath of lateral positions that drivers accept. It is generally accepted that drivers under normal conditions (i.e. not race car drivers) are satisficing controllers rather than optimizing controllers that operate based on a number of aspiration levels that they try to protect. In this paper, lower bounds on straight and curved time to line crossing (TLC) are hypothesized as aspiration levels that determine the acceptable range of lateral offsets. These lower TLC bounds also shape the speed at which a curve can be taken because when the aspiration levels cannot be reached at the current speed, a slower speed needs to be adopted to maintain sufficiently high straight and/or curved TLCs. This paper provides a theoretical exposition of straight and curved TLC as a function of environmental and driver skill factors. It provides much evidence that TLC plays a role in mediating drivers’ lateral position and speed choices.

Interacting multiple model for improving the precision of vehicle-mounted global position system

To improve the precision of low-cost, vehicle-mounted global position system (GPS), this paper presents the multi-source information fusion algorithm of vehicle navigation, which is based on the interacting multiple model (IMM). Considering vehicle kinematics and dynamic characteristics, as well as its braking capacity in extreme accelerating situations, this study establishes the clothoid model, which shows longitudinal and lateral constant speed motion, and the Adaptive Current Statistics (ACS) model, which shows the acceleration of a vehicle. Through the parametric estimation of interactivity, filtering, and updating of probability, the vehicle trajectory is predicted within a period of time, and high-precision dead-reckoning is therefore achieved. Comparative analysis shows that the above algorithm can improve the precision of vehicle-mounted GPS/inertial navigation system.