13 research outputs found
Practical Approach for Developing Lateral Motion Control of Autonomous Lane Change System
In this paper, we present a practical approach to address the vehicle lateral control problem. The proposed method can overcome practical problems associated with vehicle lane changes on highways. The vehicle state with respect to the road, which is called lateral offset, jumps in camera vision sensors when the vehicle changes lanes. Thus, in this study, we solve the state jump problem by translating it into a new domain called the cylinder domain. In addition, we proposed the design of a parameter-varying controller to overcome the nonlinear term of vehicle dynamics by considering it as a varying parameter. The proposed method does not consider the lateral offset jump when changing lanes. Furthermore, its significant advantage in terms of computation time makes it suitable for implementation in low-cost electronic control units (ECUs). The proposed algorithm is validated using MATLAB/Simulink with the vehicle dynamics analysis program CarSim
Synthesis of mesoporous gamma-aluminas of controlled pore properties using alkyl carboxylate assisted method
Mesoporous gamma-alumina (MA) was prepared by alkyl carboxylate assisted method. Pore properties of MAs could be controlled by carbon tail length of template, the molar ratio of sec-butanol to isooctane or water to aluminum precursor, and calcination conditions. The crystalline phase of MA after calcinations was gamma-Al2O3. The pore size of MAs decreased from 7.7 nm to 3.5 mn with the decrease in the ratio of water to aluminium ion, while the pore uniformity was enhanced. Isooctane as a co-solvent acted as an expander of the pores. In addition, as increasing the molar ratio of sec-butanol to isooctane, pore size increased from 2.3 nm to 3.5 nm and both pore uniformity and framework porosity was improved.N
Assessing Impacts of Climate Change and Sea-Level Rise on Seawater Intrusion in a Coastal Aquifer
The objectives of this study were to assess the climate change impacts on sea-level rise (SLR) and freshwater recharge rates and to investigate these SLR and freshwater recharge rates on seawater intrusion in coastal groundwater systems through the Saturated-Unsaturated Transport (SUTRA) model. The Gunsan tide gauge station data were used to project SLR based on polynomial regressions. Freshwater recharge rates were assumed as 10% of the projected annual precipitation under climate change. The Byeonsan2 groundwater monitoring well for seawater intrusion was selected for the study. A total of 15 scenarios, including the baseline period (2005–2015), were made based on SLR projections and estimated freshwater recharge rates. The changes in salinity relative to the baseline at the monitoring well for each scenario were investigated through the SUTRA model. From the scenario of 0.57 m SLR with a freshwater recharge rate of 0.0058 kg s−1, the largest salinity increase (40.3%) was simulated. We concluded that this study may provide a better understanding of the climate change impacts on seawater intrusion by considering both SLR and freshwater recharge rates