Improving Superelevation Attaining in Spiral Transition Based on Lateral Acceleration Rate

2021 ◽  
pp. 1-37
Author(s):  
Hossein Pourkhani ◽  
Ali Abdi Kordani
Keyword(s):  
Lateral Acceleration ◽  
Acceleration Rate

Lateral Load Transfer due to Sloshing Cargo in Partially Filled Containers

2019 ◽  
Author(s):  
Frank Otremba ◽  
José A. Romero Navarrete
Keyword(s):  
Load Transfer ◽  
Experimental Testing ◽  
Lateral Load ◽  
Safety Performance ◽  
Lateral Acceleration ◽  
Testing Device ◽  
Tilt Table ◽  
Theoretical Approaches ◽  
Acceleration Rate ◽  
Fill Level

Abstract The interaction of the liquid cargo and its carrying vehicle has been a common research subject, aiming at clarifying the potential effects of the mobility characteristics of such type of cargo, on the overall safety performance of the vehicle. While there has been extensive research on this topic, including both experimental and theoretical approaches, the comparative experimental testing of sloshing and non-sloshing cargoes has been only limited. In this paper, a scaled-down testing device that operates under the principles of a tilt table, is described and used to comparatively assess the effects, of a sloshing and non-sloshing cargo, on the lateral load transfer in the vehicle, as a function of the fill level and of the rate at which the lateral acceleration input is exerted on the vehicle-cargo system. Results suggest that the sloshing cargo generates greater load transfers, regardless of the fill level and acceleration rate input. As an average, the sloshing cargo generates a 14.75% greater load transfer.

Path Planning for Collision Avoidance Maneuver

2013 ◽  
Author(s):  
Nikolai Moshchuk ◽  
Shih-Ken Chen ◽  
Chad Zagorski ◽  
Amy Chatterjee
Keyword(s):  
Path Planning ◽  
Collision Avoidance ◽  
Optimal Path ◽  
Lateral Acceleration ◽  
Centripetal Acceleration ◽  
Target Vehicle ◽  
Acceleration Rate ◽  
Planning Algorithm ◽  
Path Planning Algorithm ◽  
Jerk Limitation

This paper summarizes the development of an optimal path planning algorithm for collision avoidance maneuver. The goal of the optimal path is to minimize distance to the target vehicle ahead of the host vehicle subject to vehicle and environment constraints. Such path constrained by allowable lateral (centripetal) acceleration and lateral acceleration rate (jerk). Two algorithms with and without lateral jerk limitation, are presented. The algorithms were implemented in Simulink and verified in CarSim. The results indicate that the lateral jerk limitation increases time-to-collision threshold and leads to a larger distance to the target required for emergency lane change. Collision avoidance path without lateral jerk limitation minimizes the distance to the target vehicle and is suitable for path tracking control in real-time application; however tracking such a path requires very aggressive control.

The Driving Severity Number (DSN) — A Step Toward Quantifying Treadwear Test Conditions

1986 ◽  
Vol 14 (3) ◽  
pp. 139-159 ◽  
Author(s):  
A. G. Veith
Keyword(s):  
Signal Processing ◽  
Ambient Temperature ◽  
Lateral Acceleration ◽  
Force Distribution ◽  
Single Index ◽  
Tire Force ◽  
Test Conditions ◽  
Wheel Revolution ◽  
High Degree ◽  
Revolution Counter

Abstract A system, called the “Driving Severity Monitor” (DSM), has been developed for characterizing tire force distribution as related to treadwear in either normal tire use or in tire fleet testing in a convoy. The system consists of an accelerometer for monitoring lateral accelerations, a wheel revolution counter, and a module for signal processing and read-out. The output of the DSM is reduced to a single index, the Driving Severity Number (DSN), which characterizes a vehicle journey. The DSN is equal to the sum of squares of lateral acceleration measured once per tire revolution during a trip, divided by the number of wheel revolutions. The DSN had a high degree of correlation (R ≧ 0.95) with treadwear in two wear programs when pavement abrasiveness was held constant. This supports the concept that the three basic treadwear components: tire force distribution, pavement abrasiveness, and ambient temperature, can be separated for better understanding of tire treadwear.

Comparison on General Track Spectrum for Chinese Main Railway Lines and Track Spectrum of American Railway Lines

2011 ◽  
Vol 250-253 ◽  
pp. 3822-3826 ◽  
Author(s):  
Xian Mai Chen ◽  
Xia Xin Tao ◽  
Gao Hang Cui ◽  
Fu Tong Wang
Keyword(s):  
Dynamic Performance ◽  
Dynamic Responses ◽  
Wave Band ◽  
Wheel Load ◽  
Railway Line ◽  
Acceleration Rate ◽  
Time Histories ◽  
Railway System ◽  
Dynamic Performances ◽  
Track Irregularity

The general track spectrum of Chinese main railway lines (ChinaRLS) and the track spectrum of American railway lines (AmericaRLS) are compared in terms of character of frequency domain, statistical property of time domain samples and dynamic performance. That the wavelength range of the ChinaRLS, which is characterized by the three levels according to the class of railway line, is less than AmericaRLS at common wave band of 1~50m is calculated. Simultaneously, the mean square values of two kinds of track spectra are provided at the detrimental wave bands of 5~10m, 10~20m, and so on. The time-histories of ChinaRLS and AmericaRLS are simulated according to the trigonometric method, and the digital statistical nature of simulated time samples is analyzed. With inputting the two kinds of time-histories into the vehicle-railway system, the comparative analysis of the two kinds of dynamic performances for ChinaRLS and AmericaRLS is done in terms of car body acceleration, rate of wheel load reduction, wheel/rail force, and the dynamic responses of track structure. The result shows that ChinaRLS can characterize the feature of the Chinese track irregularity better than AmericaRLS, the track irregularity with the ChinaRLS of 200km/h is superior to the AmericaRLS, and the track irregularity with the ChinaRLS of 160km/h corresponds to with the sixth of AmericaRLS.

scholarly journals Acute Effects on Impact Accelerations Running with Objects in the Hand

Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 550
Author(s):  
Roberto Sanchis-Sanchis ◽  
Alberto Encarnación-Martínez ◽  
Jose I. Priego-Quesada ◽  
Inmaculada Aparicio ◽  
Irene Jimenez-Perez ◽  
...  
Keyword(s):  
Mobile Phone ◽  
Step Length ◽  
Stride Frequency ◽  
Acute Effects ◽  
Shock Attenuation ◽  
Acceleration Rate ◽  
Recreational Runners ◽  
Impact Acceleration ◽  
Spatio Temporal ◽  
Extra Weight

Amateur runners usually run carrying implements in their hands (keys, a mobile phone, or a bottle of water). However, there is a lack of literature about the effects of different handloads on impact accelerations. Thus, this study aimed to analyse the effects of carrying different objects in the hand on impact accelerations during running. Nineteen male recreational runners (age 24.3 ± 6.8 years, training volume of 25 ± 7.38 km/week) performed twenty minutes of running on a treadmill at 2.78 m/s with four different conditions: no extra weight, with keys, with a mobile phone, and with a bottle of water. Impact acceleration and spatio-temporal parameters were analysed through a wireless triaxial accelerometry system composed of three accelerometers: two placed in each tibia and one placed on the forehead. A higher tibia acceleration rate in the dominant leg was observed when participants ran holding both a mobile phone (p = 0.027; ES = 0.359) and a bottle of water (p = 0.027; ES = 0.359), compared to no extra weight. No changes were observed in peak acceleration, acceleration magnitude, and shock attenuation in any other conditions. Likewise, neither stride frequency nor step length was modified. Our results suggest that recreational runners should not worry about carrying objects in their hands, like a mobile phone or a bottle of water, in short races because their effect seems minimal.

scholarly journals Research on Model Predictive Control for Automobile Active Tilt Based on Active Suspension

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 671
Author(s):  
Jialing Yao ◽  
Meng Wang ◽  
Zhihong Li ◽  
Yunyi Jia
Keyword(s):  
Load Transfer ◽  
Ride Comfort ◽  
Active Suspension ◽  
Path Tracking ◽  
Roll Angle ◽  
Lateral Acceleration ◽  
Vehicle Speed ◽  
Model Predictive Controller ◽  
Advantages And Disadvantages ◽  
Predictive Controller

To improve the handling stability of automobiles and reduce the odds of rollover, active or semi-active suspension systems are usually used to control the roll of a vehicle. However, these kinds of control systems often take a zero-roll-angle as the control target and have a limited effect on improving the performance of the vehicle when turning. Tilt control, which actively controls the vehicle to tilt inward during a curve, greatly benefits the comprehensive performance of a vehicle when it is cornering. After analyzing the advantages and disadvantages of the tilt control strategies for narrow commuter vehicles by combining the structure and dynamic characteristics of automobiles, a direct tilt control (DTC) strategy was determined to be more suitable for automobiles. A model predictive controller for the DTC strategy was designed based on an active suspension. This allowed the reverse tilt to cause the moment generated by gravity to offset that generated by the centrifugal force, thereby significantly improving the handling stability, ride comfort, vehicle speed, and rollover prevention. The model predictive controller simultaneously tracked the desired tilt angle and yaw rate, achieving path tracking while improving the anti-rollover capability of the vehicle. Simulations of step-steering input and double-lane change maneuvers were performed. The results showed that, compared with traditional zero-roll-angle control, the proposed tilt control greatly reduced the occupant’s perceived lateral acceleration and the lateral load transfer ratio when the vehicle turned and exhibited a good path-tracking performance.

Lateral obstacle avoidance control based on driving behavior recognition of the preceding vehicles in adjacent lanes

2020 ◽  
Vol 68 (10) ◽  
pp. 880-892
Author(s):  
Youguo He ◽  
Xing Gong ◽  
Chaochun Yuan ◽  
Jie Shen ◽  
Yingkui Du
Keyword(s):  
Obstacle Avoidance ◽  
Lateral Displacement ◽  
Longitudinal Velocity ◽  
Driving Behavior ◽  
Lateral Acceleration ◽  
Lateral Motion ◽  
Behavior Recognition ◽  
Dynamic Surface ◽  
Lane Changing ◽  
The Impact

AbstractThis paper proposes a lateral lane change obstacle avoidance constraint control simulation algorithm based on the driving behavior recognition of the preceding vehicles in adjacent lanes. Firstly, the driving behavior of the preceding vehicles is recognized based on the Hidden Markov Model, this research uses longitudinal velocity, lateral displacement and lateral velocity as the optimal observation signals to recognize the driving behaviors including lane-keeping, left-lane-changing or right-lane-changing; Secondly, through the simulation of the dangerous cutting-in behavior of the preceding vehicles in adjacent lanes, this paper calculates the ideal front wheel steering angle according to the designed lateral acceleration in the process of obstacle avoidance, designs the vehicle lateral motion controller by combining the backstepping and Dynamic Surface Control, and the safety boundary of the lateral motion is constrained based on the Barrier Lyapunov Function; Finally, simulation model is built, and the simulation results show that the designed controller has good performance. This active safety technology effectively reduces the impact on the autonomous vehicle safety when the preceding vehicle suddenly cuts into the lane.

scholarly journals Stage Division of Landslide Deformation and Prediction of Critical Sliding Based on Inverse Logistic Function

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1091
Author(s):  
Liulei Bao ◽  
Guangcheng Zhang ◽  
Xinli Hu ◽  
Shuangshuang Wu ◽  
Xiangdong Liu
Keyword(s):  
Direct Method ◽  
Logistic Function ◽  
New Method ◽  
Threshold Function ◽  
Critical Threshold ◽  
Time Curve ◽  
Acceleration Rate ◽  
Deformation Stages ◽  
Distance Weighting ◽  
Landslide Deformation

The cumulative displacement-time curve is the most common and direct method used to predict the deformation trends of landslides and divide the deformation stages. A new method based on the inverse logistic function considering inverse distance weighting (IDW) is proposed to predict the displacement of landslides, and the quantitative standards of dividing the deformation stages and determining the critical sliding time are put forward. The proposed method is applied in some landslide cases according to the displacement monitoring data and shows that the new method is effective. Moreover, long-term displacement predictions are applied in two landslides. Finally, summarized with the application in other landslide cases, the value of displacement acceleration, 0.9 mm/day2, is suggested as the first early warning standard of sliding, and the fitting function of the acceleration rate with the volume or length of landslide can be considered the secondary critical threshold function of landslide failure.

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