Kinematic Approach to Horizontal Curve Transition Design

2000 ◽  
Vol 1737 (1) ◽  
pp. 1-8 ◽  
Author(s):  
James A. Bonneson
Keyword(s):  
Control Process ◽  
Vehicle Control ◽  
Design Guidelines ◽  
Lateral Shift ◽  
Lateral Acceleration ◽  
Horizontal Curve ◽  
Traffic Lane ◽  
Kinematic Models ◽  
Side Friction ◽  
Kinematic Approach

Research has shown that vehicles shift laterally in the traffic lane during their entry to (or exit from) a horizontal curve. In addition, research indicates that most drivers momentarily adopt a path radius that is sharper than that of the roadway curve. A study was undertaken to investigate the causes of lateral shift and sharp path radii and to determine if they can be minimized (or eliminated) by modifying the horizontal curve transition design. From a review of the driver–vehicle control process, it was concluded that lane shift is due to unbalanced lateral accelerations that act on the vehicle as it enters the curve. These accelerations result from gravity, as effected through roadway superelevation, and side friction, caused by the steer angle of the vehicle. Kinematic models of lateral acceleration, velocity, and shift were developed. The calibrated models were used to develop design guidelines for superelevation rate and superelevation runoff location.

Investigation of Motorcycle Trajectories in 2-lane Horizontal Curves

2021 ◽  
Vol 16 ◽  
pp. 610-625
Author(s):  
Panagiotis Lemonakis
Keyword(s):  
Linear Equations ◽  
Great Accuracy ◽  
Design Guidelines ◽  
Road Segment ◽  
Small Radius ◽  
Horizontal Curve ◽  
Horizontal Alignment ◽  
The Road ◽  
Horizontal Curves ◽  
Traffic Lane

Most of the road design guidelines assume that the vehicles traverse a trajectory that coincides with the midline of the traffic lane. Based on this assumption the thresholds of various features are determined such as the maximum permissible side friction factor. It is therefore important to investigate the extent to which the trajectory of the vehicles is similar to the horizontal alignment of the road or substantial differences exist. To this end, a naturalistic riding study was designed and executed with the use of an instrumented motorcycle which measured the position of the motorcycle with great accuracy in a rural 2-lane road segment. The derived trajectories were then plotted against the horizontal alignment of the road and compared with the 3 consecutive elements which form a typical horizontal curve i.e., the entering spiral curve, the circular curve, and the exiting spiral curve. Linear equations were developed which correlate the traveled curvatures with the distance of each horizontal curve along the road segment under investigation. The process of the data revealed that the riders differ their trajectory compared to the alignment of the road. However, in small radius horizontal curves is more likely to observe curvatures that are similar to the geometric one. Moreover, the riders perform more abrupt maneuvres in the first part of the horizontal curves while they straighten the handlebars of the motorcycle before the end of the curve. The present paper aims to shed light on the behavior of motorcycle riders on horizontal curves and hence to contribute to the reduction of motorcycle accidents, particularly the single-vehicle ones.

Comfort thresholds for horizontal curve design

2009 ◽  
Vol 36 (9) ◽  
pp. 1391-1402 ◽  
Author(s):  
Dalia Said ◽  
Yasser Hassan ◽  
A.O. Abd El Halim
Keyword(s):  
Research Work ◽  
Lateral Acceleration ◽  
Horizontal Curve ◽  
Driver Behaviour ◽  
Rural Roads ◽  
Speed Reduction ◽  
Horizontal Curves ◽  
Friction Factors ◽  
Side Friction Factor ◽  
Side Friction

A key to better geometric design of highways is designing horizontal curves conforming to driver behaviour. The values of side friction factors in the point mass formula, used for the design of the minimum radius of a horizontal curve, are based on the upper threshold of driver comfort. In the current guidelines, these driver comfort levels were established in research work carried out back in the 1930s. Recently, it was found that faster drivers tend to accept higher comfort thresholds to maintain their speed and minimize speed reduction between curve and tangent. An experiment was designed at Carleton University to collect newer data on driver behaviour including speed and lateral acceleration. The results confirmed the need to revise the values of side friction demand especially for sharp curves. In addition, a model was developed to determine the side friction factor to be used in design or in consistency evaluation of horizontal curves on rural roads and ramps.

scholarly journals IS THERE A PERCEPTION-BASED ALTERNATIVE TO KINEMATIC MODELS OFTEMPO RUBATO?

2005 ◽  
Vol 23 (1) ◽  
pp. 79-85 ◽  
Author(s):  
HENKJAN HONING
Keyword(s):  
Computer Simulations ◽  
Real World ◽  
Music Performance ◽  
Rhythm Perception ◽  
Rhythmic Structure ◽  
Physical Motion ◽  
Temporal Factors ◽  
Kinematic Models ◽  
Explicit Relation ◽  
Kinematic Approach

THE RELATION BETWEEN MUSIC and motion has been a topic of much theoretical and empirical research. An important contribution is made by a family of computational theories, so-called kinematic models, that propose an explicit relation between the laws of physical motion in the real world and expressive timing in music performance. However, kinematic models predict that expressive timing is independent of (a) the number of events, (b) the rhythmic structure, and (c) the overall tempo of the performance. These factors have no effect on the predicted shape of a ritardando. Computer simulations of a number of rhythm perception models show, however, a large effect of these structural and temporal factors. They are therefore proposed as a perception-based alternative to the kinematic approach.

Design radius requirements for simple horizontal curves on three-dimensional alignments

2003 ◽  
Vol 30 (6) ◽  
pp. 1022-1033 ◽  
Author(s):  
Said M Easa ◽  
Essam Dabbour
Keyword(s):  
Three Dimensional ◽  
Design Guidelines ◽  
Comfort Level ◽  
Vertical Alignment ◽  
Passenger Cars ◽  
Minimum Radius ◽  
Horizontal Curves ◽  
Design Speed ◽  
Side Friction ◽  
Mathematical Relationships

Current North American design guides have established mathematical relationships to calculate the minimum radius required for horizontal curves as a function of design speed, maximum superelevation, and maximum side friction. For three-dimensional (3-D) alignments, the design guides consider the alignment as two separate horizontal and vertical alignments and consequently ignore the effect of vertical alignment. This paper evaluates the effect of vertical alignment on minimum radius requirements using computer simulation, with a focus on trucks. For 3-D alignments, the results showed that existing design guidelines for minimum radius need to be increased by as much as 20% to achieve the same comfort limit on flat horizontal curves. It is interesting to note that in some cases truck rollover occurred before the side-friction comfort level is reached. This indicates the need for developing a different design control for trucks on 3-D alignments than the comfort criterion used for passenger cars on flat horizontal curves. Based on the simulation results, mathematical models for design radius requirements for passenger cars and trucks were developed.Key words: geometric design, horizontal curve radius, three-dimensional alignments, vehicle stability.

scholarly journals The influence of age on the take-over of vehicle control in highly automated driving

2017 ◽  
Author(s):  
Moritz Körber ◽  
Christian Gold ◽  
David Lechner ◽  
Klaus Bengler
Keyword(s):  
Road Traffic ◽  
Age Groups ◽  
Vehicle Control ◽  
Older Drivers ◽  
Lateral Acceleration ◽  
Traffic Density ◽  
Modus Operandi ◽  
Driving Task ◽  
Critical Traffic ◽  
Over Time

The growing proportion of older drivers in the population plays an increasingly relevant role in road traffic that is currently awaiting the introduction of automated vehicles. In this study, it was investigated how older drivers (⩾60 years) compared to younger drivers (⩽28 years) perform in a critical traffic event when driving highly automated. Conditions of the take-over situation were manipulated by adding a verbal non-driving task (20 questions task) and by variation of traffic density. Two age groups consisting of 36 younger and 36 older drivers drove either with or without a non-driving task on a six-lane highway. They encountered three situations with either no, medium or high traffic density where they had to regain vehicle control and evade an obstacle on the road. Older drivers reacted as fast as younger drivers, however, they differed in their modus operandi as they braked more often and more strongly and maintained a higher time-to-collision (TTC). Deterioration of take-over time and quality caused by increased traffic density and engagement in a non-driving task was on the same level for both age groups. Independent of the traffic density, there was a learning effect for both younger and older drivers in a way that the take-over time decreased, minimum TTC increased and maximum lateral acceleration decreased between the first and the last situation of the experiment. Results highlight that older drivers are able to solve critical traffic events as well as younger drivers, yet their modus operandi differs. Nevertheless, both age groups adapt to the experience of take-over situations in the same way.

A Node-Dependent Kinematic Approach for Rotordynamics Problems

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Matteo Filippi ◽  
Enrico Zappino ◽  
Erasmo Carrera
Keyword(s):  
Dynamic Analysis ◽  
Computational Cost ◽  
Three Dimensional ◽  
Governing Equations ◽  
Three Dimensional Model ◽  
Flexible Supports ◽  
Out Of Plane ◽  
Kinematic Models ◽  
Carrera Unified Formulation ◽  
Kinematic Approach

This paper presents the dynamic analysis of rotating structures using node-dependent kinematics (NDK) one-dimensional (1D) elements. These elements have the capabilities to assume a different kinematic at each node of a beam element, that is, the kinematic assumptions can be continuously varied along the beam axis. Node-dependent kinematic 1D elements have been extended to the dynamic analysis of rotors where the response of the slender shaft, as well as the responses of disks, has to be evaluated. Node dependent kinematic capabilities have been exploited to impose simple kinematic assumptions along the shaft and refined kinematic models where the in- and out-of-plane deformations appear, that is, on the disks. The governing equations of the rotordynamics problem have been derived in a unified and compact form using the Carrera unified formulation. Refined beam models based on Taylor and Lagrange expansions (LEs) have been considered. Single- and multiple-disk rotors have been investigated. The effects of flexible supports have also been included. The results show that the use of the node-dependent kinematic elements allows the accuracy of the model to be increased only where it is required. This approach leads to a reduction of the computational cost compared to a three-dimensional model while the accuracy of the results is preserved.

Discrimination of Steady State and Transient State of Extremum Seeking Control via Sinusoidal Detection

2013 ◽  
Author(s):  
Baojie Mu ◽  
Yaoyu Li ◽  
John E. Seem
Keyword(s):  
Steady State ◽  
Control Process ◽  
Transient State ◽  
Design Guidelines ◽  
Extremum Seeking ◽  
Detection Scheme ◽  
Extremum Seeking Control ◽  
Detection Techniques ◽  
Steady State Operation ◽  
Selection Of

A major class of extremum seeking control is based on the use of periodic dither perturbation of plant input for extracting the gradient information. Presence of the dither input into the steady state operation is undesirable in practice due to the possible excessive wear of actuators. It is thus beneficial to stop the dithering action after the extremum seeking process reaches its steady state. In this paper, we propose a method for automatically discriminate between the steady state and the transient state modes of extremum seeking control process using the sinusoidal detection techniques. Some design guidelines are proposed for the parameter selection of the relevant sinusoidal detection scheme. The proposed scheme is validated with simulation study.

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