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121.
S. M. Park T. W. Park S. H. Lee S. W. Han S. K. Kwon 《International Journal of Automotive Technology》2010,11(1):49-56
In this study, a new concept for a power delivery system is developed. Power Shift Drive (PSD) Axle vehicle modeling and dynamic movement analysis are performed via simulation. The dynamic vehicle model is constructed from data obtained from the derived equation, considering the specific characteristics of each part. The model is composed of a torque converter, a gear box, a differential, hub reduction and an engine, which is the power source of the 1st forward and reverse PSD-Axle. By unifying the mathematical equations for each component, a mathematical model of the 1st forward gear is derived. The system dynamic model is created using MATLAB/Simulink based on the mathematical model. Simulation is carried out using Simulink to estimate the dynamic behavior of the PSD-Axle. In addition, the dynamo test result is used to verify the model. Finally, a successful model is created. This study will be used to establish the basic conceptual design for the PSD-Axle multi-gear system. 相似文献
122.
S. Lee D. H. Lee M. H. Kim K. C. Lee 《International Journal of Automotive Technology》2010,11(4):525-531
The controller area network (CAN) is the dominant protocol for in-vehicle network (IVN) systems because it provides bounded transmission delay among electronic control units (ECUs) at data rates between 100 Kbps and 1 Mbps. Many automotive companies have chosen the CAN protocol for their chassis network system of intelligent vehicles. However, the increasing number of ECUs in intelligent vehicles and the need for more intelligent functions require a network system with more network capacity and real-time capability. As one approach to enhance the network capacity of a CAN system, this paper introduces a CAN system with dual communication channels. This paper also presents a traffic-balancing algorithm that predicts the traffic of each channel and allocates frames to the most appropriate channel. An experimental testbed using commercial off-the-shelf microcontrollers with two CAN controllers was used to demonstrate the feasibility of the traffic-balancing algorithm. 相似文献
123.
In this paper, a predictive algorithm for vehicle trajectory control using the vehicle velocity and sideslip angle is proposed. Since the driving state of a vehicle generates nonholonomic constraint equations, it is difficult to control the trajectory with a conventional control algorithm. Furthermore, control vectors such as vehicle velocity and sideslip angle are coupled together; hence, a separate control for each variable is not suitable. In this study, a coupled control vector that combines the velocity and sideslip angle is proposed for the predictive control of vehicle trajectory. Since the coupled control vector is derived from the status of the vehicle’s motion, it is easy to generate a feedback control vector for the predictive controller. The coupled vector cannot be directly used as input to the vehicle systems; therefore, the vehicle input vector should be calculated from the control vector using a nonlinear function. Since nonlinear functions are not inserted in the control loop, they are calculated by the controller. Therefore, this method does not require a linearization process in the control logic, which enhances the stability and accuracy of the predictive controller. 相似文献
124.
Mechanisms with “negative” stiffness are a unique tool used to significantly improve vibration isolation for a vehicle driver via upgrade of the seat suspension. However, connection of such mechanisms to the suspension results in errors in the function generation process, and in most cases, makes motion impossible. An approach to type synthesis is presented in order to make this process more predictable, easy and thus more practical for the upgrade process. Structural classification of the suspensions is presented, and -an atlas of function-generating mechanisms for suspensions that reveals the effect of “negative” stiffness is completed. All of the function-generating mechanisms appear in the atlas as result of enumeration. Structural properties of novel and existing mechanisms are compared. Finally, some advantages in practical use of novel suspensions with “negative” stiffness are illustrated. 相似文献
125.
Y. T. Son B. Y. Kim K. J. Park H. Y. Lee H. J. Kim M. W. Suh 《International Journal of Automotive Technology》2009,10(5):635-644
To guarantee the efficiency of maintenance strategies for a complex structure, safety and cost limitations must be considered. This research introduces RCM-based (Reliability Centered Maintenance) life cycle optimization for reasonable maintenance. The design variable is the reliability of each part, which consists of a complex structure, while the objective is to minimize the total cost function in order to maintain the system within the desired system reliability. This research constructs the cost function that can reflect the current operating condition and maintenance characteristics of individual parts by generating essential cost factors. To identify the optimal reliability of each component in a system, this paper uses a Neuro-Evolutionary technique. Additionally, this research analyzes the reliability growth of a system by using the AMSAA (Army Material Systems Analysis Activity) model to estimate the failure rate of each part. The MTBF (Mean Time Between Failure) and the failure rate of the whole system, which is responding to the individual parts, are estimated based on the history data by using neural networks. Finally, this paper presents the optimal life cycle of a complex structure by applying the optimal reliability and the estimated MTBF to the RAMS (Reliability, Availability, Maintainability, and Safety) algorithm. 相似文献
126.
127.
Dong Won Yi Soung Hie Kim Hyung Rim Choi Nam-Kyu Park Tae-Woo Lee 《Maritime Policy and Management》2013,40(2):155-167
It is an important matter closely connected with saving logistics costs, as well as encouraging national competitive power, to improve the productivity of container terminals by efficient utilization of container terminal resources. In this respect, this paper tries to suggest a conceptual model for sharing container terminal resources, taking as a case study the Gamman Container Terminal (GCT) in the port of Pusan. In so doing, it identifies what kinds of resources can be systematically shared from the viewpoint of their common use and draws some problems resulting from terminal operation by four operators at GCT. The model does not imply the conception that each terminal has its own resources individually, but recommends that tentatively-called Container Terminal Resource Management Center (CTRMC) should be established and operated in order to save operation and investment costs and improve operational efficiency. In addition, the continuous acquisition and life-cycle support (CALS) concept is imbedded in the model so that it can control the supply and demand of resources efficiently by sharing the database, through which the CTRMC can automatically identify the status of the excess or deficit of a certain resource in each berth at GCT. 相似文献
128.
长江经济带是整个长江流域中最发达的地区,也是全国除沿海开放地区以外,经济密度最大的地带。上海港是中国第一大港,国际集装箱运输业近年来发展迅速(见表1),2000年的集装箱吞吐量更是达到561．2万TEU,跃居世界第六位。上海港之所以有如此骄人的成绩,是与长江经济带的发展密切相关的。 相似文献
129.
This paper aims to apply a supply-chain modelling and its analysis framework to the supply chain in the port industry. The simulation approach serves two purposes: to model a supply-chain network in quantity approach and to evaluate its supply-chain performance based on proposed strategies. Through the modelling works to improve the performance, components of simulation model, such as input model, strategy model, operational policy model and performance model, in the port supply chain were identified. The effects of various strategies can guide the way to administrate the supply chain in the different objectives. 相似文献
130.
The critical nature of a seaport is a connection point. In addition to the effect on port operations, a port disruption will be a strain on trade flows and the various parties concerned. Climate change, oil spill, security, social and political instability are increasing concerns over the years which would lead to higher risks. With significant growing trade volume in Asia, there is a pressing need for comprehensive studies to prepare ports for disruptions. This paper aims to analyse and categorise the disruptions that have occurred in Asian ports and estimate the likelihood of recurrence based on the data since the year 1900. Results reveal a rising trend of disruptive events. Natural disasters and labour strikes are the two main causes of port disruptions, while natural disasters lead to the highest severity in terms of cargo tons affected. Mitigation strategies proposed in terms of both preventive and reactive measures are specifically designed to reduce the likelihood and severity of the various types of port disruptions. The paper provides recommendations on risk mitigation for relevant parties. 相似文献