Study on Impact Properties of New Hydro-Pneumatic Buffer for a Metro Vehicle

2014 ◽  
Vol 978 ◽  
pp. 94-100
Author(s):  
Yi Ping Li
Keyword(s):  
Buffer Capacity ◽  
Characteristic Curve ◽  
Simulation Method ◽  
Static Characteristic ◽  
Railway Vehicle ◽  
Longitudinal Impact ◽  
Dynamics Model ◽  
New Type ◽  
Simulation Results ◽  
Buffer Structure

Analyzed and studied the hydro-pneumatic buffer structure of railway vehicle, designed a new type of hydro-pneumatic buffer and established the detailed dynamics model. Calculated the static characteristic curve of hydro-pneumatic buffer with different compression rate and dynamic characteristic curve with different impact speed through the numerical simulation method. The simulation results shows that the biggest impedance force is 1836.3KN and buffer capacity reach 221.89KJ when impact velocity of the new hydro-pneumatic buffer is 5m/s.New hydro-pneumatic buffer can improve the speed of manipulating vehicle, reduce the longitudinal impact and vibration in the train and adapt to the needs of the trains.

New-Type Energy-Recovering Hydraulic Workover Rig and the Simulation for Lifting the Tubing String

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Zhang Lujun ◽  
Xie Hengshu
Keyword(s):  
Potential Energy ◽  
Simulation Analysis ◽  
Basic Structure ◽  
Dynamics Model ◽  
Actual Measurement ◽  
Model And Simulation ◽  
Measurement Results ◽  
Tubing String ◽  
New Type ◽  
Simulation Results

A new-type energy-recovering hydraulic workover rig is researched. The basic structure and working theory of this rig are introduced. This rig decreases its equipped power remarkably compared with the conventional rig, and can recover the potential energy released by the tubing string when lowered. With infinite force-grade number, this rig can obtain the maximum lifting efficiency and energy-recovering rate. The dynamics model of lifting the tubing string is deduced and a simulation analysis is conducted. Through simulation some conclusions are obtained: (1) the greater the throttle valve path area the higher the tubing string lifting velocity, (2) the lighter the tubing string the higher the tubing string lifting velocity, and (3) the greater the displacement of the variable pump motor the higher the tubing string lifting velocity. The actual measurement results prove that the dynamics model and simulation results are basically right.

Study of HVDC System and Subsynchronous Oscillation

2015 ◽  
Vol 1092-1093 ◽  
pp. 356-361
Author(s):  
Peng Fei Zhang ◽  
Lian Guang Liu
Keyword(s):  
Power Plant ◽  
Time Domain ◽  
Simulation Method ◽  
Time Domain Simulation ◽  
Stable Convergence ◽  
Turbine Generator ◽  
Plant Model ◽  
Subsynchronous Oscillation ◽  
Hvdc System ◽  
Simulation Results

With the application and development of Power Electronics, HVDC is applied more widely China. However, HVDC system has the possibilities to cause subsynchronous torsional vibration interaction with turbine generator shaft mechanical system. This paper simply introduces the mechanism, analytical methods and suppression measures of subsynchronous oscillation. Then it establishes a power plant model in islanding model using PSCAD, and analyzes the effects of the number and output of generators to SSO, and verifies the effect of SEDC and SSDC using time-domain simulation method. Simulation results show that the more number and output of generators is detrimental to the stable convergence of subsynchronous oscillation, and SEDC、SSDC can restrain unstable SSO, avoid divergence of SSO, ensure the generators and system operate safely and stably

scholarly journals A modular framework to generate robust biped locomotion: from planning to control

2021 ◽  
Vol 3 (9) ◽  
Author(s):  
Mohammadreza Kasaei ◽  
Ali Ahmadi ◽  
Nuno Lau ◽  
Artur Pereira
Keyword(s):  
Numerical Simulations ◽  
Predictive Control ◽  
Biped Locomotion ◽  
Input Output ◽  
Dynamics Model ◽  
Biped Robots ◽  
The Core ◽  
Simulation Results ◽  
Reference Trajectories ◽  
Modular Framework

AbstractBiped robots are inherently unstable because of their complex kinematics as well as dynamics. Despite many research efforts in developing biped locomotion, the performance of biped locomotion is still far from the expectations. This paper proposes a model-based framework to generate stable biped locomotion. The core of this framework is an abstract dynamics model which is composed of three masses to consider the dynamics of stance leg, torso, and swing leg for minimizing the tracking problems. According to this dynamics model, we propose a modular walking reference trajectories planner which takes into account obstacles to plan all the references. Moreover, this dynamics model is used to formulate the controller as a Model Predictive Control (MPC) scheme which can consider some constraints in the states of the system, inputs, outputs, and also mixed input-output. The performance and the robustness of the proposed framework are validated by performing several numerical simulations using MATLAB. Moreover, the framework is deployed on a simulated torque-controlled humanoid to verify its performance and robustness. The simulation results show that the proposed framework is capable of generating biped locomotion robustly.

Design Optimization of Autoswitch Hydrogen Absorption and Desorption Device Using Metal Hydrides

2017 ◽  
Vol 15 (6) ◽  
Author(s):  
Ceng He ◽  
Yuqi Wang ◽  
Jing Song ◽  
Shanshan Li ◽  
Fusheng Yang ◽  
...  
Keyword(s):  
Metal Hydride ◽  
Cycle Time ◽  
Single Cycle ◽  
Desorption Process ◽  
Operation Conditions ◽  
Time Simulation ◽  
Structure Improvement ◽  
New Type ◽  
Simulation Results ◽  
Desorption Cycle

Abstract Metal hydride is an influential and promising material for hydrogen utilization. Researchers have carried out a large number of studies on hydrogen storage apparatus, and developed a few new devices for its promotion. Unfortunately, for most metal hydride reactors, the hydrogenation and dehydrogenation are two independent processes owing to the different required conditions, which could cause many inconveniences and safety problems to the H2 absorption & desorption cycle with high frequency and intensity. Hence we proposed a new type of autoswitch H2 absorption & desorption device based on the structure improvement, which consists of rotation disc, fixed disc and the reactor. The numerical simulation for H2 absorption/desorption using LaNi5 was accomplished, and the optimizations on both structure and operation conditions were achieved within a certain period of cycle time. Simulation results show when the single cycle time is set to 1600 s, the absorption temperature has to be lower than 45 °C (3 MPa) and pressure higher than 1.28 MPa (20 °C), and the desorption temperature should be higher than 41 °C (0.1 MPa) and pressure lower than 0.48 MPa (80 °C) under the same cycle time. Meanwhile, the effects of reaction finish time, operating temperature and H2 pressure during absorption/desorption process was investigated and simulation data were also fitted to develop the structural optimization. Under the hydrogenation/dehydrogenation conditions of 3 MPa (20 °C)/0.1 MPa (80 °C), the simulation results indicate the optimal initial reacted fraction and total cycle time are 0.07 and 1287 s, respectively. Moreover, both structures of autoswitch device with 4 and 6 openings have been optimized to satisfy the requirement of each stage. The autoswitch H2 absorption & desorption device can realize the automatic switch between hydrogenation and dehydrogenation orderly and controllably, which would provide convenience for the occasions with this demand and show its remarkable value during popularization and application.

A Robust Trajectory Tracking Control Scheme of Two-Link Flexible Manipulator

2011 ◽  
Vol 328-330 ◽  
pp. 2108-2112
Author(s):  
Jing Shuang Lu ◽  
Chun Mei Du ◽  
Rui Zhou ◽  
Na Li
Keyword(s):  
Trajectory Tracking ◽  
Tracking Control ◽  
Vertical Plane ◽  
Flexible Manipulator ◽  
System Model ◽  
Error Signal ◽  
Dynamics Model ◽  
Trajectory Tracking Control ◽  
Control Scheme ◽  
Simulation Results

A simple dynamics model is established based on the two-link flexible manipulator moving within the vertical plane, and a robust simple control scheme is put forward. The advantages of this scheme are simple and good robustness. Only the error signal is needed when designing the control scheme and the acquirement of control signal does not depend on the system model. The simulation results show that this method has a good robustness and stability.

An Efficient Transient Simulation Method for a Volume Dynamics Model

2018 ◽  
Author(s):  
Masahiro Kurosaki ◽  
Minoru Sasamoto ◽  
Kentaro Asaka ◽  
Keiko Nakamura ◽  
Daiki Kakiuchi
Keyword(s):  
Integration Method ◽  
Simulation Method ◽  
Euler Method ◽  
Test Model ◽  
Dynamics Model ◽  
Engine Operation ◽  
Turbine Engine ◽  
Engine Model ◽  
Influence Coefficients ◽  
Transient Simulations

This paper presents an efficient numerical integration method for a volume dynamics model in gas turbine engine transient simulations. It is a modified implicit Euler method that allows a time increment that would not be stable with the explicit Euler method. The Jacobian matrix of a nonlinear engine model is evaluated along the steady state engine operation line and scheduled as a function of the corrected shaft speed in advance, eliminating the necessity of computing during the simulation. The proposed method was applied to transient simulations of a compressor rig test model composed of a compressor, a nozzle with variable geometry and a volume placed between them. The eigenvalues of the simplified volume dynamics were analytically derived. It is shown that they are functions of the characteristic time of the volume defined by mass present in the volume divided by mass flow rate flowing into and out of the volume and dimensionless influence coefficients of nearby components.

A Reformative Simulation Method of Motor Pole Core Vibration Characteristics

2013 ◽  
Vol 331 ◽  
pp. 118-123
Author(s):  
Tian Hui Ding ◽  
Yun Hua Chen ◽  
Lei Tian
Keyword(s):  
Reference Value ◽  
Simulation Method ◽  
Vibration Characteristics ◽  
New Method ◽  
Motor Design ◽  
Simulation Results ◽  
Vibration Performance

As to directing motor design, it is very important to make sure that the motor’s forecast of vibration performance has reference value. So, it must need motor’s parts vibration characteristics simulation results are so close to their characteristics. This paper puts forward a new simulation method of motor pole core vibration characteristics, this method includes setting anisotropy material attributes multipartite, getting attributes parameters values which are based on recommended fitting curves, modeling and equating windings, equating dipping lacquer and so on. Combining with experiments, the new method is validated its availability.

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.

Construction of a Rational Tire Model for High Fidelity Vehicle Dynamics Simulation Under Extreme Driving and Environmental Conditions

2010 ◽  
Author(s):  
S. C¸ag˘lar Bas¸lamıs¸lı ◽  
Selim Solmaz
Keyword(s):  
Vehicle Dynamics ◽  
Dynamics Simulation ◽  
High Fidelity ◽  
Tire Model ◽  
Dynamics Model ◽  
Vehicle Model ◽  
Prospective Design ◽  
Magic Formula ◽  
Rational Models ◽  
Simulation Results

In this paper, a control oriented rational tire model is developed and incorporated in a two-track vehicle dynamics model for the prospective design of vehicle dynamics controllers. The tire model proposed in this paper is an enhancement over previous rational models which have taken into account only the peaking and saturation behavior disregarding all other force generation characteristics. Simulation results have been conducted to compare the dynamics of a vehicle model equipped with a Magic Formula tire model, a rational tire model available in the literature and the present rational tire model. It has been observed that the proposed tire model results in vehicle responses that closely follow those obtained with the Magic Formula even for extreme driving scenarios conducted on roads with low adhesion coefficient.

Simulation Investigation of Tangential-Feed Centerless Grinding Process Performed on Surface Grinder

2009 ◽  
Vol 626-627 ◽  
pp. 23-28
Author(s):  
Wei Xing Xu ◽  
Yong Bo Wu ◽  
Takashi Sato ◽  
Wei Min Lin
Keyword(s):  
Elastic Deformation ◽  
Process Parameters ◽  
Simulation Method ◽  
Machining Accuracy ◽  
Grinding Process ◽  
Elasticity Parameter ◽  
Grinding Method ◽  
Centerless Grinding ◽  
Simulation Results ◽  
Grinding Technique

In our previous study, a new centerless grinding method using surface grinder was proposed. This paper describes a simulation method for investigating the workpiece rounding process in which a model taking the elastic deformation of the machine into consideration is created, and revealing how the process parameters affect the machining accuracy in the new grinding technique. In addition, a practice way to determine the machining-elasticity parameter showing the elastic deformation is developed. The simulation results are compared to show the effect of process parameters on the machining accuracy.

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