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Cao J.,Shanghai JiaoTong University | Cao J.,Shanghai Motor Vehicle Inspection Center | Lu H.,Shanghai JiaoTong University | Guo K.,Shanghai JiaoTong University | Zhang J.,Shanghai Motor Vehicle Inspection Center
Mathematical Problems in Engineering | Year: 2013

Based on the preview optimal simple artificial neural network driver model (POSANN), a new driver model, considering jerky dynamics and the tracing error between the real track and the planned path, is established. In this paper, the modeling for the driver-vehicle system is firstly described, and the relationship between weighting coefficients of driver model and system parameters is examined through test data. Secondly, the corresponding road test results are presented in order to verify the vehicle model and obtain the information on drive model and vehicle parameters. Finally, the simulations are carried out via CarSim. Simulation results indicate that the jerky dynamics need to be considered and the proposed new driver model can achieve a better path-following performance compared with the POSANN driver model. © 2013 Jianyong Cao et al.


Cao J.,Shanghai JiaoTong University | Cao J.,Shanghai Motor Vehicle Inspection Center | Jing L.,China Automotive Technology and Research Center | Guo K.,Shanghai JiaoTong University | Yu F.,Shanghai JiaoTong University
Mathematical Problems in Engineering | Year: 2013

This paper proposes the integrated controller of the yaw and rollover stability controls based on the prediction model. A nonlinear 3-DoF vehicle model with a piecewise linearization tire model is built up as the rollover predictive model, and its accuracy is verified by vehicle tests. A yaw stability controller and a rollover stability controller are proposed, respectively. Then coordinated control strategy is investigated for the integration of vehicle yaw and roll stability controls. The additional yaw torque and braking torque of each wheel are calculated. The unified command of valves is sent combined with ABS control algorithm. Virtual tests in CarSim are carried out, including slalom condition and double-lane change condition. Results indicate that the coordinated control algorithm improves vehicle yaw and roll stability effectively. © 2013 Jianyong Cao et al.


Hao D.,Tongji University | Shen J.,Shanghai Motor Vehicle Inspection Center | Hou Y.,Tongji University | Zhou Y.,Tongji University | Wang H.,China National Institute of Standardization
International Journal of Chemical Engineering | Year: 2016

Based on a review analysis of empirical fuel cell polarization curve models in the literature, an improved model that can predict fuel cell performance with only measured current-voltage data is developed. The fitting characteristics of this new model are validated by fitting bench test data and road test data. In the case of bench test data, a comparison of the new model and two representative models is conducted, and the results show that the new model presents the best fitting effects over a whole range of current densities. Moreover, the fitted ohmic resistances derived from the new model show good agreement with the measured values obtained through a current interruption test. In the case of using road test data, the new model also presents excellent fitting characteristics and convenience for application. It is the author's belief that the new model is beneficial for the application-oriented research of fuel cells due to its prominent features, such as conciseness, flexibility, and high accuracy. © 2016 Dong Hao et al.


Hou Y.,Tongji University | Hao D.,Tongji University | Shen J.,Shanghai Motor Vehicle Inspection Center | Li P.,Tongji University | And 2 more authors.
International Journal of Hydrogen Energy | Year: 2016

The vehicular fuel cell stack is unavoidably impacted by the vibration and shock in the real-world due to the road unevenness. However, influences of vibration on fuel cell stack have yet to be investigated completely. In this paper, the performance of a fuel cell stack is experimentally studied in terms of gas-tightness, voltage degradation, AC impedance spectra, polarization curve and characteristic parameters in polarization curve through long-term strengthened road vibration tests, in order to investigate the influences of road-induced vibration on performance degradation of fuel cell stack. The vibration tests are carried out on a six-channel multi axial simulation table with the vibration excitation spectra originally derived from the strengthened road of the ground prove. During the vibration test, several kinds of performance test including gas-tightness test, AC impedance diagnosis and polarization curve test are conducted at regular intervals. After the vibration test, the gas leakage rate of anode reaches 1.73 times of the initial value. The open circuit voltage and rated voltage decreases by 0.90% and 3.58%, respectively. Meanwhile, the performance of individual cell voltage uniformity becomes worse distinctly. With the increase of vibration duration, the ohmic resistance obtained from AC impedance diagnosis ascends approximately linearly and presents a growth of 5.36% ultimately. An improved empirical fuel cell polarization curve model is adopted to fit the current-voltage data and estimate the characteristic parameters which decide the shape of polarization curve. It is noted that the limiting current density declines distinctly and the mass transfer loss increases mainly at the range of high current densities. The results indicate that the long-term strengthened road vibration condition exerts a significant influence on the durability of fuel cell stack. Copyright © 2016 Hydrogen Energy Publications, LLC.


Wang R.,Shanghai JiaoTong University | Chen J.,Shanghai JiaoTong University | Li J.Q.,Shanghai Motor Vehicle Inspection Center
Journal of Physics: Conference Series | Year: 2012

Wave superposition method is a numerical method for sound field reconstruction, which can be applied in sound source identification and fault diagnosis. This study aims to obtain some guidelines to increase the reconstruction accuracy. A number of influence factors are analyzed through theoretical analysis and numerical simulation, including equivalent sources, measurement array, reconstruction distance and regularization methods. Results show that the distribution of the equivalent sources has a great impact on the reconstruction accuracy. The equivalent sources should be collocated interior to the radiator. It's better that the equivalent source surface conforms to the radiator's surface, while the measurement array doesn't need to be conformal to the radiator's surface. Relatively, the reconstruction distance has a little influence on the reconstruction accuracy. At last, four different regularization methods together with two regularization parameter selection approaches are combined with wave superposition method to solve the ill-posed problem. Comparative results indicate that Tikhonov and truncate singular value decomposition regularization methods work well with wave superposition method. In sum, these conclusions are useful to get higher reconstruction accuracy and consequently help wave superposition method become an effective fault diagnosis tool.


Hao D.,Tongji University | Hou Y.,Tongji University | Shen J.,Shanghai Motor Vehicle Inspection Center | Ma L.,Tongji University
SAE Technical Papers | Year: 2016

The vehicular fuel cell stack is unavoidably impacted by the vibration in the real-world usage due to the road unevenness. However, effects of vibration on stacks have yet to be completely understood. In this work, the mechanical integrity and gas-tightness of the stack were investigated through a strengthen road vibration test with a duration of 200 h. The excitation signals applied in the vibration test were simulated by the acceleration of the stack, which were previously measured in a vehicle vibration test. The load signals of the vehicle vibration test were iterated through a road simulator from vehicle acceleration signals which were originally sampled in the proving ground. Frequency sweep test was conducted before and after the vibration test. During the vibration test, mechanical structure inspection and pressure maintaining test of the stack were conducted at regular intervals. Experimental results show that the mechanical integrity of the stack remains unchanged, while the gas-tightness degrades obviously. The pressure drop rates of anode and cathode experience a rapid rise at first and then a slow increase to 237 % and 390 % of the original value, respectively. Meanwhile, the rated power of the stack declines by 2.21 % of the initial value. © Copyright 2016 SAE International.


Xu Y.,Shanghai Motor Vehicle Inspection Center | Yan J.,Shanghai Motor Vehicle Inspection Center | Wu J.,Shanghai Motor Vehicle Inspection Center | Shen H.,Shanghai Motor Vehicle Inspection Center
Zhuzao/Foundry | Year: 2012

Cavities are common defects in the production of die casting. The porosity of metal die casting measured by using quantitative metallographic method was discussed in this paper. The quality of castings was evaluated according to the measured results of porosity. The accurate porosity results based on preparing good sample, and the effects of the coatings and the flow of molten metal on the gas porosity were researched.


Hao T.,Shanghai Normal University | Yang H.,Shanghai Motor Vehicle Inspection Center | Xu H.B.,Shanghai Normal University
Advanced Materials Research | Year: 2012

A great deal of energy can be absorbed when the inner diameter of a steel tube is inflated by inserting a rigid rod. This procedure has some advantages: high energy absorbed per length, constant compress force and robust to the direction of insertion force. Therefore, this is very fit for energy-absorber for some light vehicles. The effect of energy-absorbing is investigated by impact test and simulation in this paper. Applications for full frontal impact and offset frontal impact of a minibus are discussed.


Gao P.,Tongji University | Zhu X.,Tongji University | Ma Z.,Tongji University | Zhu S.,Shanghai Motor Vehicle Inspection Center
Applied Mechanics and Materials | Year: 2013

Based on huge data got during the EXPO period, this paper researched the running character of the buses run on EXPO Guozhan line and constructed the driving cycle. According to statistical principle, defined thirty six characteristics and chosen twenty three characteristics of them as index characteristics. In this paper we constructed the driving cycle by ways of the difference at index characteristics. When the difference between the totality and the temporary cycle is within 10%, the temporary cycle could be received as the driving cycle of the totality. The research gave the driving cycle of the bus line running in China. In the following research and development of the electric bus, Researchers could use this driving cycle to helping develop, test and verify the electric bus. © (2013) Trans Tech Publications, Switzerland.


Xu Y.,Shanghai Motor Vehicle Inspection Center | Shen H.,Shanghai Motor Vehicle Inspection Center | Yin H.,Shanghai Motor Vehicle Inspection Center
Jinshu Rechuli/Heat Treatment of Metals | Year: 2011

The connecting pipe made of 409L stainless steel cracked in the weld joint during the service period. The fracture morphology, microstructure and chemical composition of the connecting pipe were analyzed by SEM, EDAX test and metalloscope. The results show that the cracking is mainly stress corrosion cracking (SCC) that occurs in weld joint caused by sulfuric acid and sulfurous acid solution, which is produced by the reaction of SO 2 in the combustion exhaust and condensed water. In addition, coarse grain of the weld joint of the pipe promotes the intergranular corrosion.

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