Study on buses rollover warning based on roll angle threshold

2010 ◽  
Author(s):  
Wei Zhou ◽  
Wen-liang Li ◽  
Ying Zhu ◽  
Jiaxin Liu ◽  
Wen-liang Li
Keyword(s):  
Roll Angle ◽  
Rollover Warning

Vehicle rollover warning system based on TTR method with Inertial Measurement

2021 ◽  
Author(s):  
Mengmeng Wang ◽  
Jinhao Liu ◽  
Hongye Zhang ◽  
Linjie Gan ◽  
Xiangbo Xu ◽  
...  
Keyword(s):  
Steady State ◽  
Load Transfer ◽  
Warning System ◽  
Front Wheel ◽  
Roll Angle ◽  
Lateral Acceleration ◽  
Vehicle Speed ◽  
Matlab Simulink ◽  
Vehicle Rollover ◽  
Rollover Warning

Abstract This paper presents a theoretical and experimental study conducted on the rollover warning of wheeled off-road operating vehicles. The time to rollover (TTR) warning algorithm was studied with real-time vehicle roll angle and roll angle velocity as the input variables, and lateral load transfer ratio (LTR) was used as the rollover determination index. Subsequently, a vehicle dynamics model was built using CarSim software, and a warning algorithm was established in the MATLAB/Simulink environment. The rollover joint simulation in CarSim and MATLAB/Simulink was conducted under typical working conditions. Finally, combined with inertial measurements, a rollover warning system was independently developed. In addition, the rollover warning system was installed on a light forest firefighting truck to verify the feasibility of the system via a real vehicle experiment, and the law of vehicle rollover motion was also studied. The serpentine experiment and steady-state rotation experiment were conducted. The experimental results showed that at identical front-wheel steering angles, the roll angle and lateral acceleration increased with an increase in the vehicle speed. Furthermore, for identical vehicle speeds, the roll angle and lateral acceleration of the vehicle increased with an increase in the front-wheel steering angle. The dangerous vehicle speed was 50 km/h in the serpentine condition and 40 km/h in the steady-state rotation condition. The risk trend and alarm signal obtained by the rollover warning system were consistent with the actual situation. Thus, this can assist drivers in judging the rollover risk and effectively improve the active safety of special vehicles. Furthermore, it also provides a reference for further research on active rollover control technology of special vehicles.

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.

scholarly journals A Low-Cost MEMS Missile-Borne Compound Rotation Modulation Scheme

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4910
Author(s):  
Xiaoqiao Yuan ◽  
Jie Li ◽  
Xi Zhang ◽  
Kaiqiang Feng ◽  
Xiaokai Wei ◽  
...  
Keyword(s):  
Rotation Axis ◽  
Low Cost ◽  
Roll Angle ◽  
Modulation Scheme ◽  
Navigation Systems ◽  
Rotation Scheme ◽  
Compound Rotation ◽  
Error Accumulation ◽  
Axis Rotation ◽  
Single Axis Rotation

Rotation modulation (RM) has been widely used in navigation systems to significantly improve the navigation accuracy of inertial navigation systems (INSs). However, the traditional single-axis rotation modulation cannot achieve the modulation of all the constant errors in the three directions; thus, it is not suitable for application in highly dynamic environments due to requirements for high precision in missiles. Aiming at the problems of error accumulation and divergence in the direction of rotation axis existing in the traditional single-axis rotation modulation, a novel rotation scheme is proposed. Firstly, the error propagation principle of the new rotation modulation scheme is analyzed. Secondly, the condition of realizing the error modulation with constant error is discussed. Finally, the original rotation modulation navigation algorithm is optimized for the new rotation modulation scheme. The experiment and simulation results show that the new rotation scheme can effectively modulate the error divergence of roll angle and improve the accuracy of roll angle by two orders of magnitude.

Numerical and Experimental Approaches to Investigate the Stability of a Motorcycle Vehicle

2006 ◽  
Author(s):  
Federico Cheli ◽  
Marco Bocciolone ◽  
Marco Pezzola ◽  
Elisabetta Leo
Keyword(s):  
Degrees Of Freedom ◽  
Structural Parameters ◽  
Experimental Tests ◽  
Roll Angle ◽  
Longitudinal Motion ◽  
Reference Trajectory ◽  
Steering Angle ◽  
Steady State Condition ◽  
The Stability ◽  
Linearized Model

The study of motorcycle’s stability is an important task for the passenger’s safety. The range of frequencies involved for the handling stability is lower than 10 Hz. A numerical model was developed to access the stability of a motorcycle vehicle in this frequency range. The stability is analysed using a linearized model around the straight steady state condition. In this condition, the vehicle’s vertical and longitudinal motion are decoupled, hence the model has only four degrees of freedom (steering angle, yaw angle, roll angle and lateral translation), while longitudinal motion is imposed. The stability was studied increasing the longitudinal speed. The input of the model can be either a driver input manoeuvre (roll angle) or a transversal component of road input able to excite the vibration modes. The driver is introduced in the model as a steering torque that allows the vehicle to follow a reference trajectory. To validate the model, experimental tests were done. To excite the vehicle modes, the driver input was not taken into account considering both the danger for the driver and the repeatability of the manoeuvre. Two different vehicle configurations were tested: vehicle 1 is a motorcycle [7] and vehicle 2 is a scooter. Through the use of the validated model, a sensitivity analysis was done changing structural (for example normal trail, steering angle, mass) and non structural parameters (for example longitudinal speed).

A Stochastic Theory for Nonlinear Ship Rolling in irregular Seas

1982 ◽  
Vol 26 (04) ◽  
pp. 229-245 ◽  
Author(s):  
J. B. Roberts
Keyword(s):  
Markov Processes ◽  
Digital Simulation ◽  
Stochastic Theory ◽  
Simple Expression ◽  
Roll Angle ◽  
Rolling Motion ◽  
Approximate Theory ◽  
Averaging Techniques ◽  
Good Agreement ◽  
Ship Rolling

By a combination of averaging techniques with the theory of Markov processes, an approximate theory is developed for the rolling motion of a ship in beam waves. A simple expression is obtained for the distribution of the roll angle, and is tested by a comparison with a set of digital simulation estimates due to Dalzell. Good agreement is obtained over a realistic range of damping values.

Effectiveness of Truck Rollover Warning Systems

2001 ◽  
Vol 1779 (1) ◽  
pp. 134-140 ◽  
Author(s):  
Derek Baker ◽  
Rob Bushman ◽  
Curtis Berthelot
Keyword(s):  
North America ◽  
Warning System ◽  
Warning Systems ◽  
Commercial Vehicles ◽  
Decision Criteria ◽  
Warning Messages ◽  
System A ◽  
Different Types ◽  
Rollover Warning

Different types of intelligent rollover system deployed by road agencies across North America are investigated. The importance of weight is addressed for maximum effectiveness of rollover warning messages for commercial vehicles in a potential rollover situation on sharp curves or exit ramps. The type of information that may be used to activate a rollover is discussed to analyze the number of correctly warned vehicles compared with the number of false warnings generated by the rollover warning system. A case study of the effectiveness of an intelligent rollover system is presented. On the basis of this case study, it was found that speed-based rollover warning systems generated anywhere from 44 percent to 49 percent more false rollover warnings for commercial vehicles than did rollover warning systems that employed weight information in the rollover decision criteria.

Roll angle estimation for smart munitions under GPS jamming environment

2008 ◽  
Vol 41 (2) ◽  
pp. 9499-9504 ◽  
Author(s):  
Han Sung Lee ◽  
HeeYoung Park ◽  
KwangJin Kim ◽  
Jang Gyu Lee ◽  
Chan Gook Park
Keyword(s):  
Roll Angle ◽  
Angle Estimation

scholarly journals Accurate Model-Based Point of Gaze Estimation on Mobile Devices

Vision ◽  
2018 ◽  
Vol 2 (3) ◽  
pp. 35 ◽  
Author(s):  
Braiden Brousseau ◽  
Jonathan Rose ◽  
Moshe Eizenman
Keyword(s):  
Eye Tracking ◽  
Mobile Devices ◽  
Head Movements ◽  
Roll Angle ◽  
New Method ◽  
Estimation Methods ◽  
Infrared Light ◽  
Gaze Estimation ◽  
Tracking Systems ◽  
Estimation Models

The most accurate remote Point of Gaze (PoG) estimation methods that allow free head movements use infrared light sources and cameras together with gaze estimation models. Current gaze estimation models were developed for desktop eye-tracking systems and assume that the relative roll between the system and the subjects’ eyes (the ’R-Roll’) is roughly constant during use. This assumption is not true for hand-held mobile-device-based eye-tracking systems. We present an analysis that shows the accuracy of estimating the PoG on screens of hand-held mobile devices depends on the magnitude of the R-Roll angle and the angular offset between the visual and optical axes of the individual viewer. We also describe a new method to determine the PoG which compensates for the effects of R-Roll on the accuracy of the POG. Experimental results on a prototype infrared smartphone show that for an R-Roll angle of 90 ° , the new method achieves accuracy of approximately 1 ° , while a gaze estimation method that assumes that the R-Roll angle remains constant achieves an accuracy of 3.5 ° . The manner in which the experimental PoG estimation errors increase with the increase in the R-Roll angle was consistent with the analysis. The method presented in this paper can improve significantly the performance of eye-tracking systems on hand-held mobile-devices.

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