A novel tripped rollover prevention system for commercial trucks with air suspensions at low speeds

2017 ◽  
Vol 232 (11) ◽  
pp. 1516-1527 ◽  
Author(s):  
Haitao Ding ◽  
Amir Khajepour ◽  
Yanjun Huang
Keyword(s):  
Road Safety ◽  
Commercial Vehicles ◽  
Dynamics Model ◽  
Air Spring ◽  
Severe Injuries ◽  
Low Speed ◽  
Suspension Systems ◽  
Rollover Prevention ◽  
Air Suspension ◽  
Prevention System

This paper presents a novel system to avoid tripped rollovers at low-speed operations for commercial vehicles with air suspension systems. This is of particular significance since truck rollovers have become a serious road safety problem, which usually lead to severe injuries and fatalities. Several active anti-rollover systems have been proposed in the past two decades; however, most of them focus on untripped rollover prevention instead of the tripped rollovers. Up to now, very few pieces of literature discuss the approaches that are used to avoid tripped rollovers of trucks. Furthermore, the air suspension is widely used for commercial vehicles, thus it provides an opportunity to prevent rollovers when properly manipulated. Therefore, a novel tripped rollover prevention system is proposed for trucks at low-speed operations with air suspensions. A roll dynamics model with an air spring is built to investigate the dynamic behavior and the time response of the whole system. More importantly, the feasibility of this new anti-rollover system is discussed and verified by the co-simulations in TruckSim and MATLAB/Simulink under two possible tripped rollover conditions.

scholarly journals Evaluation of Dynamic Load Reduction for a Tractor Semi-Trailer Using the Air Suspension System at all Axles of the Semi-Trailer

Actuators ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 12
Author(s):  
Dang Viet Ha ◽  
Vu Van Tan ◽  
Vu Thanh Niem ◽  
Olivier Sename
Keyword(s):  
Dynamic Load ◽  
Pearson Correlation ◽  
Suspension System ◽  
Leaf Spring ◽  
Load Reduction ◽  
Full Model ◽  
Air Spring ◽  
Suspension Systems ◽  
Air Suspension ◽  
Spring Suspension

The air suspension system has become more and more popular in heavy vehicles and buses to improve ride comfort and road holding. This paper focuses on the evaluation of the dynamic load reduction at all axles of a semi-trailer with an air suspension system, in comparison with the one using a leaf spring suspension system on variable speed and road types. First, a full vertical dynamic model is proposed for a tractor semi-trailer (full model) with two types of suspension systems (leaf spring and air spring) for three axles at the semi-trailer, while the tractor’s axles use leaf spring suspension systems. The air suspension systems are built based on the GENSYS model; meanwhile, the remaining structural parameters are considered equally. The full model has been validated by experimental results, and closely follows the dynamical characteristics of the real tractor semi-trailer, with the percent error of the highest value being 6.23% and Pearson correlation coefficient being higher than 0.8, corresponding to different speeds. The survey results showed that the semi-trailer with the air suspension system can reduce the dynamic load of the entire field of speed from 20 to 100 km/h, given random road types from A to F according to the ISO 8608:2016 standard. The dynamic load coefficient (DLC) with the semi-trailer using the air spring suspension system can be reduced on average from 14.8% to 29.3%, in comparison with the semi-trailer using the leaf spring suspension system.

Decoupling Capability of Levitation Frames for Medium-Low Speed Maglev Trains

2021 ◽  
pp. 2150178
Author(s):  
Junxiong Hu ◽  
Weihua Ma ◽  
Shihui Luo ◽  
Wan Liu ◽  
Tianwei Qu ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Stability Control ◽  
Test Method ◽  
Air Spring ◽  
Low Speed ◽  
End Set

Medium-low speed maglev trains (MSMTs) with a levitation gap of only 8–10[Formula: see text]mm need an adequate decoupling capability on the levitation frames to ensure stability control in levitation, while preventing the train from rolling sideways when in landing. Based on the geometric and kinematic relationships, two types of levitation frames are studied, i.e. levitation frame with end-set air spring (LFEAS) and levitation frame with mid-set air spring (LFMAS). For each levitation frame, the decoupling process and mechanism are analyzed, the analytical equations for the kinematic attitude are derived, the decoupling capability under different excitations is calculated, along with the effect of various structural parameters assessed. In addition, a test method is designed for the rolling of the levitation frame, particularly with the anti-rolling capability of the LFMAS measured. The results indicate that oscillation of the hanger rods and anti-rolling beams can compensate for displacement when the motion of the levitation frame is decoupled, which is the key to the decoupling capability. Also, the position of the anti-rolling devices and the length of hanger rods do not affect significantly the decoupling capability. However, a longer anti-rolling beam is more conducive to decoupling, but it does not affect the anti-rolling capacity of the levitation frame. The maximum roll computed of the LFMAS is 2.84[Formula: see text]mm, which meets the anti-rolling requirement.

Dynamic model of an air spring and integration into a vehicle dynamics model

2008 ◽  
Vol 222 (10) ◽  
pp. 1813-1825 ◽  
Author(s):  
F Chang ◽  
Z-H Lu
Keyword(s):  
Dynamic Model ◽  
Vehicle Dynamics ◽  
Simulation Method ◽  
Heat Transfer Process ◽  
Spring Model ◽  
Dynamics Model ◽  
Air Spring ◽  
Full Vehicle ◽  
Body Dynamics ◽  
Multi Body

It is worthwhile to design a more accurate dynamic model for air springs, to investigate the dynamic behaviour of an air spring suspension, and to analyse and guide the design of vehicles with air spring suspensions. In this study, a dynamic model of air spring was established, considering the heat transfer process of the air springs. Two different types of air spring were tested, and the experimental results verified the effectiveness of the air spring model compared with the traditional model. The key factors affecting the computation accuracy were studied and checked by comparing the results of the experiments and simulations. The new dynamic model of the air spring was integrated into the full-vehicle multi-body dynamics model, in order to investigate the air suspension behaviour and vehicle dynamics characteristics. The co-simulation method using ADAMS and MATLAB/Simulink was applied to integration of the air spring model with the full-vehicle multi-body dynamics model.

scholarly journals Methods for controlling the elastic damping characteristics of pneumatic seat suspensions

2021 ◽  
Vol 1 (2) ◽  
pp. 27-33
Author(s):  
M.V. Lyashenko ◽  
◽  
V.V. Shekhovtsov ◽  
P.V. Potapov ◽  
A.I. Iskaliyev ◽  
...  
Keyword(s):  
Vibrational Energy ◽  
Working Fluid ◽  
Technical Solution ◽  
Technical Literature ◽  
Seat Suspension ◽  
Suspension Systems ◽  
Damping Characteristics ◽  
Air Suspension ◽  
Wide Range ◽  
Vehicle Seat

The pneumatic seat suspension is one of the most important, and in some situations, one of the key components of the vibration protection system for the human operator of the vehicle. At the present stage of scientific and technical activities of most developers, great emphasis is placed on controlled seat suspension systems, as the most promising systems. This article analyzes the methods of controlling the elastic damping characteristics of the air suspension of a vehicle seat. Ten dif-ferent and fairly well-known methods of changing the shape and parameters of elastic damping characteristics due to electro-pneumatic valves, throttles, motors, additional cavities, auxiliary mechanisms and other actuators were considered, the advantages, application limits and disad-vantages of each method were analyzed. Based on the results of the performed analytical procedure, as well as the recommendations known in the scientific and technical literature on improving the vibration-protective properties of suspension systems, the authors proposed and developed a new method for controlling the elastic-damping characteristic, which is implemented in the proposed technical solution for the air suspension of a vehicle seat. The method differs in the thing that it im-plements a cyclic controlled exchange of the working fluid between the cavities of the pneumatic elastic element and the additional volume of the receiver on the compression and rebound strokes, forming an almost symmetric elastic damping characteristic, and partial recuperation of vibrational energy by a pneumatic drive, presented in the form of a rotary type pneumatic motor. In addition, the method does not require an unregulated hydraulic shock absorber, while still having the ad-vantage of improved vibration-proof properties of the air suspension of a vehicle seat over a wide range of operating influences.

scholarly journals Optimal design parameters of air suspension systems for semi-trailer truck. Part 2: results and discussion

2020 ◽  
Vol 33 ◽  
pp. 147-152
Author(s):  
Le Van Quynh ◽  
Nguyen Van Tuan ◽  
Vi Thi Phuong Thao ◽  
Le Quang Duy
Keyword(s):  
Optimal Design ◽  
Design Parameters ◽  
Suspension Systems ◽  
Air Suspension

Experimental study on vertical vibration characteristics of medium-low speed maglev vehicle when standing still on steel beams

2021 ◽  
pp. 095440972110324
Author(s):  
Miao Li ◽  
Xiaohao Chen ◽  
Shihui Luo ◽  
Weihua Ma ◽  
Cheng Lei ◽  
...  
Keyword(s):  
Coupled System ◽  
Vertical Vibration ◽  
Vibration Characteristics ◽  
Steel Beams ◽  
Steel Beam ◽  
Air Spring ◽  
Low Speed ◽  
Maglev Vehicle ◽  
Excited Vibration ◽  
Eigen Frequencies

Levitation stability is the very basis for the dynamic operation of Electromagnetic Suspension (EMS) medium-low speed maglev trains (MSMT). However, self-excited vibration tends to occur when the vehicle is standing still above the lightweight lines, which remains a major constraint to the promotion of medium-low speed maglev technology. In order to study the vertical vibration characteristics of the coupled system of MSMT when it is standing still above lightweight lines, levitation tests were carried out on two types of steel beams: steel beam and active girder of the turnout, with a newly developed maglev vehicle using levitation frames with mid-set air spring. Firstly, modal tests were carried out on the steel beam to determine its natural vibration characteristics; secondly, the acceleration signals and the dynamic displacement signals of the air spring obtained at each measurement point were analyzed in detail in both the time and frequency domains, and the vertical ride comfort was assessed by means of the calculated Sperling index. Subsequently, theoretical explanations were given for the occurrence of self-excited vibration of coupled system from the perspective of the vehicle-to-guideway vibration energy input. Results show that the eigen frequencies of the vehicle on the steel beam and the turnout are 9.65 Hz and 2.15 Hz, respectively, the former being close to the natural frequency of the steel beam while the latter being close to the natural frequency of the air spring suspension system, thus causing the self-excited vibration of the coupled system. It is recommended to either avoid the main eigen frequencies of the coupled system or to increase the damping of the corresponding vibration modes to guarantee a reliable coupled system for its long-term performance. These results may provide valuable references for the optimal design of medium-low speed maglev systems.

scholarly journals Case Study for Road Safety Audit of Aurangabad City

2020 ◽  
Vol 170 ◽  
pp. 06008
Author(s):  
Prashant Awsarmal ◽  
S. L. Hake ◽  
Shubham Vaidya ◽  
P. K. Bhandari ◽  
M. P. Wagh
Keyword(s):  
Road Safety ◽  
Human Life ◽  
Research Work ◽  
Police Department ◽  
Road Accident ◽  
Audit Process ◽  
Severe Injuries ◽  
The Road ◽  
Road Geometry ◽  
Road Safety Audit

Efficient road network is a part-n-parcel of rapid industralization, urbanization and development of nation. While designing roads and highways, main emphasis is given on speed which will help to reduce time of journey and save fuel. But safety of drivers and passengers travelling along road is also important. In past, it was observed that while travelling, due to excess speed passengers safety was compromised. It will lead to accidents. It may cause severe injuries and loss of human life. Therefore it is important to check every aspect of vehicles as well as road during its design, construction and throughout the life of the road. Road safety audit is conducted to check performance of new road projects on grounds of offering maximum safety. Also checks are applied to study performance of existing roads to suggest repairs, rehabiliatation and maintenance work in order to improve condition of roads. During audit process, accident prone locations are identified. Past accident record from traffic department, Police department, hospitals etc are referred to understand damage that had occured. Even road geometry is investigated on technical basis. In present investigation, particular stretch of Beed Bypass Road passing through Aurangabad city in Maharashtra state, India was selected. On this road, accident sites where major accidents occurred in past were identified and investigated for different parameters. Based upon study, different causes of accidents and thereafter preventive methods were recommended during research work.

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