Digital exchange of design models between marine equipment libraries using hybrid neutral formats

The selection of marine equipment is a time-consuming process for a ship outfitting designer. The inefficiency originates from the paper-based exchange of design information between shipyards and equipment manufacturers. We propose a method to exchange equipment models for electronic commerce. Shipyard practices were investigated to find out how the outfitting CAD library is being used. We also surveyed international standards for the exchange of digital equipment models, and analyzed the macroparametric methodology. We propose a hybrid method to represent the geometric information using STEP AP203 or the macroparametric method. The nongeometric information is defined according to the Parts Library (PLIB) standard. We implement a pilot system and test it with a ship design data set. The equipment model proposed can be used in the design process with heterogeneous shipbuilding CAD systems. The equipment model can improve the design and purchase process in shipyards.     

Damper modeling for dynamic simulation of a large bus with MR damper

In this study, a large bus is tested to measure its dynamic response by the single-lane change test and the rapid stop test. A full car model is established by ADAMS/Car for computer simulation. For multibody modeling of a large bus, user-defined templates are used in the simulation. Simulation results of the single-lane change test and the rapid braking test are compared to the results of the physical experiments, in which several sensors are installed to measure the vehicle’s responses. The results obtained from the simulation show good agreement with the tests’ results. A dynamic model for the MR(magnetic-rheological) damper is also developed by employing the Magic Formula model, which is widely used in the nonlinear modeling of a tire. Bump simulation of a full car with the MR damper is carried out to verify the performance of the MR damper. The comparison of the simulation results obtained with the MR damper model to the results obtained with the traditional passive damper model showed improved response of the vehicle with the MR damper.     

Development of a navigation algorithm with dead reckoning for unmanned ground vehicles

A navigation algorithm is indispensable for Unmanned Ground Vehicles (UGVs). During driving, UGVs follow a global path. In this study, we propose a navigation algorithm using Real Time Kinematic (RTK)-Differential Global Positioning System (DGPS) units and encoders to complement global path planning. Sometimes GPS systems lose their signals and receive inaccurate position data due to many factors, such as edifice and barrier obstructions. This paper shows that GPS deviations can be solved using a Dead Reckoning (DR) navigation method with encoders and that position errors can be decreased through the use of RTK-DGPS units. In addition to this method, we will introduce a new waypoint update algorithm and a steering algorithm using RTK-DGPS units.     

Piston-temperature measuring system using electromagnetic induction with verification by a telemetry system

The development of an inner-piston-chamber temperature measurement system is a necessary step in engine development or when solving other fundamental problems related to automotive engines. There are various pre-existing measurement methods available, e.g., the linkage method, piston telemetry, templog, and the electromagnetic induction method. In this study, we first redesigned the coil sensor used in the electromagnetic induction method using PEEK and then used Taguchi methods to reduce the number of experiments in the development process and finally utilized piston telemetry via Bluetooth to verify the precision and accuracy of the redesigned PEEK coil sensor and electromagnetic induction method. The results displayed a reproducibility within 0.5 degrees and an accuracy within 2 degrees Celsius.     

Realization of pmp-based control for hybrid electric vehicles in a backward-looking simulation

Optimal control is generally not possible without information about the future coming up, and it is not easy to obtain an optimal solution even though the information is given a priori. In this paper, a control concept based on Pontryagin’s Minimum Principle (PMP) is introduced as an efficient solution to generate an optimal control trajectory for Hybrid Electric Vehicles (HVEs) when the performance of the vehicles is evaluated on scheduled driving cycles at a simulation level. The main idea of the control concept is to minimize Hamiltonian, which is interpreted as equivalent fuel consumption, and the Hamiltonian is characterized by a co-state, which is interpreted as a weighting factor for the electrical usage. A key aspect of the control problem is that an appropriate initial condition of the co-state is required to satisfy the boundary condition of the problem. In this study, techniques to calculate the Hamiltonian in different hybrid configurations are introduced, and a methodology to look for the initial condition of the co-state is studied, so that the controller is able to realize a desired State Of Charge (SOC) trajectory. To address the issue, we utilize a shooting method with multiple initial conditions based on the concept of the Newton-Raphson method, and all these techniques are realized in a backward looking simulator. The simulation results show that the PMP-based control is a very efficient approach to produce the optimal control trajectory, and the performance is compared to the optimal solution solved by Dynamic Programming (DP).     

Effects of injection parameters on the spray characteristics of swirl and slit injectors using the Mie-scattering method

We investigated the effects of injection parameters such as injection pressure, ambient pressure, and ambient temperature on spray characteristics. We calculated the turbulence occurring point (t _c ), defined as the time required to generate a vortex, and the deceleration point (t _b ), defined as the time when spray penetration begins to decelerate, to elucidate the breakup mechanism of the test injectors. The spray velocity coefficient (C_v) was obtained to evaluate the spray characteristics. As the ambient pressure increases in the case of a slit injector, C_v decreases. We investigated the effects of nozzle tip shape according to injection pressure, ambient pressure, and fuel properties on spray characteristics and provide a C_v value of 0.38 for the swirl injector with a spray angle of 60° and the slit injector under atmospheric conditions. The value of C_v in the case of a slit injector was reduced by increasing the ambient pressure. Our results suggest that C_v of a swirl injector is constant regardless of changes in ambient pressure, injection pressure, and fuel properties. On the other hand, C_v of a slit injector is altered by changes in ambient pressure.     

Development of electrostatic diesel particulate matter filtration systems combined with a metallic Flow-Through Filter and electrostatic methods

A 3000 cc diesel engine attached to an engine dynamo was used to test three newly developed electrostatic Diesel Particulate matter filtration Systems (DPS 1, 2, and 3) under four steady-state engine operating conditions: idle, 2000 rpm with no load, and 2000 rpm under 25% and 50% loads. Of the two developed alternatives, DPS 1 and DPS 2, DPS 2 comprises an ionization section, electrostatic field additional section and Flow-Through Filter (FTF), which achieved almost 90% removal of particulate matter (PM) under the engine’s operating conditions, and the efficiency of the FTF was maintained between 20% and 50%. Comparing the long-term performance of DPS 2 and DPS 3 (effectively a serial combination of two DPS 2s) with a commercially-available Diesel Particulate Filter (DPF), the DPS 2 and DPS 3 achieved almost the same efficiency for removing PM as the DPF but had significantly improved (75%∼90% lower) differential pressure drops.     

Design and implementation of a new clamping force estimator in Electro-Mechanical Brake systems

In this paper, an improved clamping force estimator is proposed for Electro-Mechanical Brake (EMB) systems by using the motor rotor position information and the hysteresis characteristics of mechanical parts in the EMB. A cascaded type of a force/position control system with a force sensor or an estimator was designed and implemented to control the clamping force and to keep the clearance gap in EMB systems. The EMB Hardware-In-the-Loop-Simulation (HILS) results show that the proposed force estimator yields better estimation performance than the existing estimator and that the clamping force control system based on the estimator can be also used for the fault tolerant control of the system.     

欧洲客车设计

自然,欧洲客车设计也受到技术与生产的限制。自20世纪初到50年代的几十年时间里,大部分制造商在生产和销售适应于市场的车辆,这些车辆的可靠性非常好,无可挑剔,有些甚至可以说是难得的珍品。渐渐地,像所有经济领域一样,客车经济的信息增强了,单凭客车的外观与美学功能,就能对销