Multibody Dynamics Simulation and Bogie Structure Evaluation for Active-Bogie Steering Truck

2007 ◽  
Author(s):  
N. Miyajima ◽  
A. Matsumoto ◽  
Y. Suda ◽  
Y. Sato ◽  
H. Ohno ◽  
...  
Keyword(s):  
Traffic Safety ◽  
High Speed ◽  
Dynamics Simulation ◽  
Transition Curve ◽  
Steering Control ◽  
Active Steering ◽  
Steering Mechanism ◽  
Curving Performance ◽  
Hunting Stability ◽  
Structure Evaluation

Railway truck is necessary to have excellent curving performance as well as high speed hunting stability, but generally they are contrary to each other. In order to realize the compatibility, many trucks with passive steering mechanism have been studied, and some of them are realized on service operation. In order to realize further improvement of bogie steering ability on sharp curve, active steering control can give effective performance, and is considered as the latest topic. As an example of the active steering bogie, the bogie with actuators between wheelsets and bogie frame is considered. The bogie mechanism realizes effective steering but requires many actuators results in complex mechanism. The truck treated here has simple but effective mechanism: Actuators are attached only between car body and truck frame. When railway trucks negotiate sharp curve running, the rolling radius difference between inside and outside wheels cannot be obtained sufficiently, and the attitude of the truck becomes so-called “insufficient steering condition”. Considering the phenomena, if the truck frame is steered by actuators toward “radial steering position of the truck”, the improvement of curving performance of the truck can be realized. This is the first concept of active-bogie-steering (ABS) truck. In this paper, detailed study and evaluation for ABS (Active-Bogie-Steering) bogie will be presented. Validity tests were carried out with the bogie on rolling test stand in NTSEL (National Traffic Safety and Environment Laboratory), which can simulate curve-running condition including transition curve. Bogie parameters and steering actuator characteristics are elaborately identified in order to compare the experimental results with multi-body dynamics simulation. According to the test results and numerical simulation, the effectiveness of the proposed bogie mechanism and control are proved.

Path-Following Steering Control for Articulated Vehicles

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
B. A. Jujnovich ◽  
D. Cebon
Keyword(s):  
High Speed ◽  
Path Following ◽  
Steering Control ◽  
Active Steering ◽  
High Speeds ◽  
Wide Range ◽  
Articulated Vehicles ◽  
Speed Range ◽  
Heavy Goods Vehicles ◽  
Low Speeds

Passive steering systems have been used for some years to control the steering of trailer axles on articulated vehicles. These normally use a “command steer” control strategy, which is designed to work well in steady-state circles at low speeds, but which generates inappropriate steer angles during transient low-speed maneuvers and at high speeds. In this paper, “active” steering control strategies are developed for articulated heavy goods vehicles. These aim to achieve accurate path following for tractor and trailer, for all paths and all normal vehicle speeds, in the presence of external disturbances. Controllers are designed to implement the path-following strategies at low and high speeds, whilst taking into account the complexities and practicalities of articulated vehicles. At low speeds, the articulation and steer angles on articulated heavy goods vehicles are large and small-angle approximations are not appropriate. Hence, nonlinear controllers based on kinematics are required. But at high-speeds, the dynamic stability of control system is compromised if the kinematics-based controllers remain active. This is because a key state of the system, the side-slip characteristics of the trailer, exhibits a sign-change with increasing speeds. The low and high speed controllers are blended together using a speed-dependent gain, in the intermediate speed range. Simulations are conducted to compare the performance of the new steering controllers with conventional vehicles (with unsteered drive and trailer axles) and with vehicles with command steer controllers on their trailer axles. The simulations show that active steering has the potential to improve significantly the directional performance of articulated vehicles for a wide range of conditions, throughout the speed range.

scholarly journals Active steering control based on preview theory for articulated heavy vehicles

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0252098
Author(s):  
Jie Tian ◽  
Qingkang Zeng ◽  
Peng Wang ◽  
Xiaoqing Wang
Keyword(s):  
High Speed ◽  
Single Point ◽  
Path Tracking ◽  
Lateral Stability ◽  
Steering Control ◽  
Linear Quadratic ◽  
Low Speed ◽  
Active Steering ◽  
Simulation Results ◽  
Active Steering Control

This paper investigates the active steering control of the tractor and the trailer for the articulated heavy vehicle (AHV) to improve its high-speed lateral stability and low-speed path following. The four-degree-of-freedom (4-DOF) single track dynamic model of the AHV with a front-wheel steered trailer is established. Considering that the road information at the driver’s focus is the most clear and those away from the focus blurred, a new kind controller based on the fractional calculus, i.e., a focus preview controller is designed to provide the steering input for the tractor to make it travel along the desired path. In addition, the active steering controllers based on the linear quadratic regulator (LQR) and single-point preview controller respectively are also proposed for the trailer. However, the latter is designed on the basis of the articulation angle between the tractor and trailer, inspired by the idea of the driver’s single-point preview controller. Finally, the single lane change maneuver and 90o turn maneuver are carried out. And the simulation results show that compared with the single-point preview controller, the new kind preview controller for the tractor can have good high speed maneuvering stability and low speed path tracking ability by adjusting the fractional order of the controller. On this basis, three different AHVs with the same tractor are simulated and the simulation results show that the AHV whose trailer adopts the single-point preview controller has better high-speed lateral stability and low-speed path tracking than the AHV whose trailer adopts the LQR controller.

Freight Truck for Higher Speed Operations

2010 ◽  
Author(s):  
Anand R. Vithani ◽  
Graydon F. Booth ◽  
Anand Prabhakaran ◽  
Som P. Singh ◽  
David C. Brabb ◽  
...  
Keyword(s):  
High Speed ◽  
Dynamics Simulation ◽  
Maximum Speed ◽  
Lateral Instability ◽  
Railroad Industry ◽  
Industry Standard ◽  
Increased Risk ◽  
Disc Brakes ◽  
Curving Performance ◽  
Freight Trucks

The current freight railroad operations are restricted to a maximum speed of 80 mph partly due to lateral instability of conventional freight trucks at higher speeds. The three-piece truck, a workhorse of the railroad industry for over 100 years, and its variations are susceptible to hunt at 50–55 mph when empty and 90–100 mph in loaded conditions. Design attempts to increase high-speed stability generally lead to diminished curving performance and increased risk of derailment. In this paper we describe a true pendulum suspension based freight truck that is designed to achieve stable operations up to 150 mph without compromising curving performance. The truck’s performance has been analyzed using an industry standard vehicle dynamics simulation tool. The AAR MSRP M-1001 Chapter 11 ‘Service-Worthiness Tests and Analyses For New Freight Cars’ were used to qualify the design where applicable. Traditional tread brakes are supplemented with axle-mounted disc brakes to provide safe braking capabilities beyond 110 mph. Two full-size 70-ton prototypes have been assembled using off-the-shelf and fabricated components. Yard tests have shown that the truck curves properly even under very tight curving conditions.

On the Planning and Construction of Railway Curved Track

2021 ◽  
Vol 13 (2) ◽  
Author(s):  
Sono Bhardawaj ◽  
Rakesh Chandmal Sharma ◽  
Sunil Kumar Sharma ◽  
Neeraj Sharma
Keyword(s):  
High Speed ◽  
Time Derivative ◽  
Railway Track ◽  
Lateral Acceleration ◽  
Transition Curve ◽  
Railway Vehicle ◽  
Geometric Conditions ◽  
Curve Track ◽  
Curved Track ◽  
Transition Curves

Increasing demand for railway vehicle speed has pushed the railway track designers to develop high-quality track. An important measure of track quality is the character of the transition curve track connecting different intersecting straight tracks. A good transition curve track must be able to negotiate the intermittent stresses and dynamic effects caused by changes in lateral acceleration at high speed. This paper presents the constructional methods for planning transition curves considering the dynamics of movement. These methods consider the non-compensated lateral acceleration, deviation in lateral acceleration and its higher time derivatives. This paper discusses the laying methods of circular, vertical and transition curves. Key aspects in laying a curved track e.g. widening of gauge on curves are discussed in this paper. This paper also suggests a transition curve which is effective not only from a dynamic point of view considering lateral acceleration and its higher time derivative but also consider the geometric conditions along with the required deflection angle.

Stochastic Transverse Earthquake-Induced Damage Track Irregularity Spectrum Considering the Uncertainty of Track-Bridge System

2021 ◽  
pp. 2140004
Author(s):  
Yulin Feng ◽  
Yu Hou ◽  
Lizhong Jiang ◽  
Wangbao Zhou ◽  
Jian Yu ◽  
...  
Keyword(s):  
Simulation Model ◽  
Traffic Safety ◽  
High Speed ◽  
Residual Deformation ◽  
High Speed Railway ◽  
Marquardt Algorithm ◽  
Earthquake Action ◽  
Track Irregularity ◽  
Track Bridge ◽  
Bridge System

The track irregularity spectrum of longitudinally connected ballastless track (LCBT)-bridge systems of high-speed railway was proposed in this paper. First, a simulation model of an LCBT-continuous girder bridge was established by considering the influences of approach bridges and subgrade with track structure. Further, a large number of sample analyses were carried out by taking into account the uncertainty of LCBT-bridge systems and stochastic behaviors of ground motions based on the simulation model. The damage laws of residual deformation of track-bridge system after earthquake actions were studied. Then, an interlayer deformation coordination relationship (IDCR) considering the track irregularity caused by earthquake-induced damage of bearings was developed, and the superposed track irregularity samples were obtained. Finally, by using the improved Blackman–Turkey method and Levenberg–Marquardt algorithm, the LCBT irregularity spectrum, track irregularity spectrogram, track irregularity limit spectrum, and a fitting formula for the track irregularity spectrum on a bridge after the action of earthquakes were obtained. Results obtained from the fitting formula and IDCR were compared, and they indicated that tracks undergone significant high-frequency irregularity diseases after the earthquake action. It was found that the track irregularity spectrum could be roughly divided into three ranges: high-, medium- and low-frequency wavebands. Consequently, this led to an application of a three-segment power function for the fitting of the track irregularity spectrum after the earthquake action. The track irregularity spectrum after the action of earthquakes provides an important theoretical basis for the establishment of seismic design methods for high-speed railway bridges based on the traffic safety performance.

scholarly journals Research on Bogie Frame Lateral Instability of High-Speed Railway Vehicle

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Chen Wang ◽  
Shihui Luo ◽  
Ziqiang Xu ◽  
Chang Gao ◽  
Weihua Ma
Keyword(s):  
High Speed ◽  
Dynamics Simulation ◽  
Lateral Acceleration ◽  
Railway Vehicle ◽  
Lateral Instability ◽  
Bogie Frame ◽  
High Speed Railway ◽  
Long Time ◽  
Line Test ◽  
Equivalent Conicity

In order to find out the reason for the bogie frame instability alarm in the high-speed railway vehicle, the influence of wheel tread profile of the unstable vehicle was investigated. By means of wheel-rail contact analysis and dynamics simulation, the effect of tread wear on the bogie frame lateral stability was studied. The result indicates that the concave wear of tread is gradually aggravated with the increase of operation mileage; meanwhile the wheel-rail equivalent conicity also increases. For the rail which has not been grinded for a long time, the wear of gauge corner and wide-worn zone is relatively severe; the matching equivalent conicity is 0.31-0.4 between the worn rail and the concave-worn-tread wheel set. The equivalent conicity between the grinded rail and the concave-worn tread is below 0.25; the equivalent conicities are always below 0.1 between the reprofiled wheel set and various rails. The result of the line test indicates that the lateral acceleration of bogie frame corresponding to the worn wheel-rail can reach 8.5m/s2, and the acceleration after the grinding is reduced below 4.5m/s2. By dynamics simulation, it turns out that the unreasonable wheel-rail matching relationship is the major cause of the bogie frame lateral alarm. With the tread-concave wear being aggravated, the equivalent conicity of wheel-rail matching constantly increases, which leads to the bogie frame lateral instability and then the frame instability alarm.

Study on Bonding Properties of Copper and Aluminum in Nano Scale Using Molecular Dynamics Simulation

2012 ◽  
Vol 152-154 ◽  
pp. 183-187 ◽  
Author(s):  
Quang Cherng Hsu ◽  
Yen Yu Cheng ◽  
Bao Hsin Liu
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Bonding Strength ◽  
High Speed ◽  
Tensile Force ◽  
Pure Aluminum ◽  
Pure Copper ◽  
Dynamics Simulation ◽  
Low Speed ◽  
Speed Condition

According to MD simulation results, pressing depth between two bonding materials will affect bonding strength. Alloy material (Al0.9Cu0.1) had void defect phenomenon in low bonding speed condition because the increasing chance of atom migration which will result in low bonding strength. High tensile speed causes material fracture phenomena happen earlier than low speed. Material stress in low speed is smaller than in high speed. Fracture morphology of material is different in different tensile speed. In low speed condition, material can be stretched thinner than in high speed condition. Material in high temperature has greater kinetic energy than low temperature; therefore, material in high temperature has better formability and behaves larger tensile strain than low temperature. For pure aluminum, when temperature raises to 900K which is close to melting point (933K), its crystal structure is no longer belongs to F.C.C. structure, so bonding strength is weaker than low temperature. Large size material has larger contact area than small size material; therefore, the tensile force and tensile strength of the former are larger than the latter. The order of bonding strength for these three materials is: binary alloy > pure copper > pure aluminum.

scholarly journals Experimental and Numerical Analysis of High-Speed Internally Cooled Milling

CONVERTER ◽  
2021 ◽  
pp. 748-756
Author(s):  
Ningxia Yin Et al.
Keyword(s):  
High Speed ◽  
End Milling ◽  
Double Helix ◽  
Channel Structure ◽  
Dynamics Simulation ◽  
Thermal Dissipation ◽  
Machined Surface ◽  
Milling Tool ◽  
Internally Cooled ◽  
Cooling Technology

Advanced cooling technology is a crucial measure of thermal dissipation for high-speed end-milling. In order to get an appropriate cooling technology and decrease the negative effects of traditional wet cutting, internally cooled cutting has been paid more and more attention. Because of interrupted cutting and uneven force, there was few application and investigation on internally cooled end-milling. In the paper, the effect of the end-milling tool with different internally cooled channel structure has been researched by experiment and theoretical analysis. The experimental results indicate that the end-milling tool with double helix channels carried out best machined surface quality. And the experiment result was also been analyzed and explained by computational fluid dynamics simulation, which provides a basis for the applying of the high-speed internally cooled end-milling tool.

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