http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Lignin Based Flexible Electromagnetic Shielding PU Synergized with Graphite
Jia Zhang,Yunxia Qi,Yumei Zhang,Jinchi Duan,Bairun Liu,Baijun Liu,Zhaoyan Sun,Yiquan Xu,Wei Hu,Niaona Zhang 한국섬유공학회 2021 Fibers and polymers Vol.22 No.1
In this paper, lignin (L)-based polyurethane (FeGLPU) with excellent electromagnetic shielding properties wasprepared and studied. The modified reduced iron powder was modified with KH550, and then the obtained modified reducediron powder (Fe) was mixed with lignin, polyethylene glycol 200 (PEG200), hexamethylene diisocyanate (HDI) and graphite(G) to in-situ synthesize the FeGLPU. The thermal stability, mechanical properties, electronic conductivity, and morphologyof the composite FeGLPU were characterized in detail. The electromagnetic interference shielding effectiveness (EMI SE) ofFeGLPU was tested in the frequency range of 8.2-26.5 GHz. When the content of Fe and G was fixed at 10 % and the lignincontent was 5 %, the maximum EMI SE was 21.6 dB, and the frequency width of EMI SE greater than 10 dB was 18.3 GHz. The conductivity was 4.27×10-4 S/m, and the tensile strength of Fe10G10L5PU reached 11.7 MPa. When the lignin contentincreased to be 20 %, the maximum EMI SE was 22.5 dB, and the frequency width of EMI SE greater than 10 dB was18.3 GHz. The conductivity was 1.06×10-2 S/m, and the thermal decomposition temperature T5 (5 % weight loss) reached234 °C. The obtained excellent EMI SE should be due to the synergistic effect of Fe, G and lignin. It can be observed fromthe SEM observation that the G and Fe are uniformly dispersed in PU matrix with strong interfacial interaction. It wasillustrated that the prepared FeGLPU was with efficient electromagnetic shielding properties, good mechanical properties,and high thermal stability. This lignin based electromagnetic shielding PU was proposed to have broad application prospectsdue to its low expenses and ecology friendliness.
SPATIAL-BASED PREDICTIVE CONTROL FOR VEHICLE COLLISION AVOIDANCE BY STEERING MANEUVERS
Shaosong Li,Yunsheng Tian,Xiaofeng Yue,Niaona Zhang,Shujun Wang 한국자동차공학회 2022 International journal of automotive technology Vol.23 No.1
A hierarchical vehicle collision avoidance control method based on model predictive control is presented in this study. In the upper level of the controller, a spatial-based two-degree-of-freedom vehicle model is used for dynamic path planning to decrease the computational burden of the algorithm. Obstacles and road boundaries are translated into spatialbased constraints on system states. An objective function that considers tire adhesion margin is introduced to the path tracking controller to enhance vehicle safety. Meanwhile, the dynamic constraints of vehicle lateral acceleration, sideslip, and tire slip angles are designed in accordance with the tire-road adhesion coefficient. A time-based nonlinear model predictive controller is also designed and compared with the proposed method to verify the effectiveness and superiority of the latter. Theoretical analyses and simulation results indicate that the proposed collision avoidance control system has good ollision avoidance effect.
Zeng Li,Gaojian Cui,Shaosong Li,Niaona Zhang,Yunsheng Tian,Xiaoqiang Shang 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.4
To address the failure to consider vehicle states in region of interest (ROI) prediction, we propose the use of a Kalman filter to estimate the position of vehicles relative to lanes by vehicle states on the basis of a vehicle–road micro traffic model in the world coordinate system. The central position of the ROI is determined through a combination of optimal preview time theory with the ROI prediction. The range of the ROI is determined by offsetting upward, downward, leftward, and rightward from the central position of the ROI. The left and right ROI are processed separately to detect lane lines. Simulation results show that the proposed prediction method reduces the ROI range, and the model predictive control controller can make the vehicle run smoothly from the initial position to the road centerline.