A New Predictive Lateral Load Transfer Ratio for Rollover Prevention Systems

2013 ◽  
Vol 62 (7) ◽  
pp. 2928-2936 ◽  
Author(s):  
Chad Larish ◽  
Damrongrit Piyabongkarn ◽  
Vasilios Tsourapas ◽  
Rajesh Rajamani
2012 ◽  
Vol 162 ◽  
pp. 505-514 ◽  
Author(s):  
Mathieu Richier ◽  
Roland Lenain ◽  
Benoit Thuilot ◽  
Christophe Debain

In this paper, an algorithm dedicated to light ATVs, which estimates and anticipates the rollover, is proposed. It is based on the on-line estimation of the Lateral Load Transfer (LLT), allowing the evaluation of dynamic instabilities. The LLT is computed thanks to a dynamical model split into two 2D projections. Relying on this representation and a low cost perception system, an observer is proposed to estimate on-line the terrain properties (grip conditions and slope), then allowing to deduce accurately the risk of instability. Associated to a predictive control algorithm, based on the extrapolation of riders action, the risk can be anticipated, enabling to warn the pilot and to consider the implementation of active actions.


2001 ◽  
Author(s):  
A. Scott Lewis ◽  
Moustafa El-Gindy

Abstract This paper presents new active control strategies to prevent heavy vehicle rollover and focuses mainly on cases of maneuver-induced rollover such as rollover in cornering and lane-change maneuvers. Two performance measures as control strategies are explored: the lateral load transfer ratio and the trailer lateral acceleration. A nonlinear 75,000 pound 5-axle tractor/semitrailer computer simulation model has been used to demonstrate the effectiveness of the proposed active control system. A new non-linear sliding mode controller has been designed and found to be effective in improving the dynamic performance and roll stability, regardless of parameter uncertainties, such as tires or suspension characteristics. The controller torque requirement is limited by the differential dynamic braking forces that the tractor drive axles are able to produce as a function of the applied dynamic loads and road surface condition. The results show that with this new controller, the vehicle lateral acceleration can be controlled to prevent rollover without significant change of the vehicle trajectory when active yaw torque is applied to the tractor drive axles. Also, simulation results indicate that the vehicle rollover might be prevented using either the lateral load transfer ratio or the lateral acceleration at the trailer centre of gravity as control strategies.


Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2790
Author(s):  
Seongjin Yim ◽  
Wongun Kim

This paper presents a method to prevent the rollover of autonomous electric road sweepers (AERS). AERS have an articulated frame steering (AFS) mechanism. Moreover, the heights of the center of gravity of the front and rear bodies are high. As such, they are prone to rolling over at low speeds and at small articulation angles. A bicycle model with a nonlinear tire model was used as a vehicle model for AERS. Using that vehicle model, path tracking and speed controllers were designed in order to follow a predefined path and speed profile, respectively. To check the rollover propensity of AERS, load transfer ratio (LTR) based the rollover analysis was completed. Based on the results of the analysis, a rollover prevention scheme was proposed. To validate the proposed scheme, a simulation was conducted using a U-shaped path under constant speed conditions. From the simulation, it was shown that the proposed scheme is effective in preventing AERS from rolling over.


2018 ◽  
Vol 41 (3) ◽  
pp. 859-874 ◽  
Author(s):  
Wanzhong Zhao ◽  
Lin Ji ◽  
Chunyan Wang

A rollover dynamic model that merges the active front steering model and differential braking model is established in this paper. After analyzing and improving the existing rollover evaluation method, a new evaluation method that takes both sprung mass and under-sprung mass into consideration is proposed. The reliability of the improved LTR (lateral load transfer rate) is confirmed by simulation results obtained from MATLAB and CARSIM where, all of three evaluation methods are taken under the same condition. The accuracy of the rollover evaluation index depends on the centroid height of under-sprung mass and the ratio of under-sprung mass and under-sprung mass. In order to achieve the desired tracking effect and anti-jamming capability, an integrated rollover control system based on active steering and differential braking is designed where a H∞ controller is adopted. The results of simulation under J-turn condition indicate that the control system has strong stability and robustness. When the vehicle is under the risk of rollover and reaches the setting threshold, the designed H∞ controller will actively keep the vehicle under the critical state.


Author(s):  
Te Pei ◽  
Tong Qiu ◽  
Jeffrey A. Laman

Abstract The present study comprehensively evaluates the improvement in lateral load-carrying capacity of steel pipe piles by adding steel plates (fins) at grade level. This configuration of steel fin pile foundations (SFPFs) is effective for applications where high lateral loads are encountered and rapid pile installation is advantageous. An integrated finite element analysis (FEA) was conducted. The FEA utilized an Abaqus model, first developed to account for the nonlinear soil-pile interaction, and then calibrated and validated against well-documented experimental and filed tests in the literature. The validated FEA model was subsequently used to conduct a parametric study to understand the effect of fin geometry on the load transfer mechanism and the response of SFPFs subjected to lateral loading at pile head. The behavior of SFPFs at different displacement levels and load levels was studied. The effect of the relative density of soil on the performance of SFPFs was also investigated. Based on the numerical simulation results, the optimal fin width for maximum improvement in lateral load-carrying capacity was suggested and the underlining mechanism affecting the efficiency of fins was explained.


2020 ◽  
Vol 10 (20) ◽  
pp. 7230
Author(s):  
Xu Zhang ◽  
Chuanxue Song ◽  
Shixin Song ◽  
Jingwei Cao ◽  
Da Wang ◽  
...  

Vehicle rollover has always been a highly dangerous condition that can cause severe traffic casualties. In this work, a 14-degree-of-freedom vehicle model in MATLAB/Simulink is constructed with the vehicle suspension system dynamics. The validity of the model is verified by comparing with the CarSim model. Then an optimal distribution of damping force strategy with continuous damping control is proposed by combining the traditional lateral load transfer ratio control with optimized equations of suspension damping force. The damping force compensation of the left and right sides is the core of the optimal distribution of damping force strategy. The effectiveness and optimization effect of the optimal distribution of damping force strategy is proved by the simulation results under the fishhook and crosswind tests. The result shows that continuous damping control has evident control effects on vehicle rollover compared with passive suspension. The optimal distribution of the damping force strategy with continuous damping control has a great better performance than traditional continuous damping control, and it provides a certain assistance to vehicle handling stability.


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