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1
Content available Analysis on electromechanical coupling vibration characteristics of in-wheel motor in electric vehicles considering air gap eccentricity
Li Y., Wu H., Xu X., Cai Y., Sun X.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2019
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Vol. 67, nr 5
851--862
EN
The distortion of air gap magnetic field caused by the rotor eccentricity contributes to the electromechanical coupling vibration of the brushless DC (BLDC) permanent magnet in-wheel motor (PMIWM) in electric vehicles (EV). The comfort of the BLDC in-wheel motor drive (IWMD) EV is seriously affected. To deeply investigate the electromechanical coupling vibration of the PMIWM under air gap eccentricity, the PMIWM, tyre and road excitation are analyzed first. The influence of air gap eccentricity on air gap magnetic density is investigated. The coupling law of the air gap and the unbalanced magnetic force (UMF) is studied. The coupling characteristics of eccentricity rate, air gap magnetic density, UMF, phase current and vibration acceleration are verified on the test bench in the laboratory. The mechanism of the electro-mechanical coupling vibration of the BLDC PMIWM under air gap static eccentricity (SE), dynamic eccentricity (DE) and hybrid eccentricity (HE) is revealed. DE and HE deteriorate the vibration acceleration amplitude, which contributes the electromechanical coupling vibration of the PMIWM. The research results provide a solid foundation for the vibration and noise suppression of the PMIWM in distributed drive EV.
2
Content available Simulation and experimental study of SCR injection system
Du J., Zhang Y., Cai Y.
Polish Maritime Research
|
2018
|
S 2
49--55
EN
According to actual engineering test, we design a linear controlled spray ammonia grille, and apply it to the SCR injection system of ship tail gas treatment. In this paper, the geometric model of ammonia injection grid was built in the flue of diesel engine, and the effects of spray atomization, ammonia uniformity and urea droplet distribution on spray atomization were simulated. Then the test bench was set up to observe the injection status of the ammonia injection grille. The NOx content of the outlet was measured by the original data of the flue gas, and the experimental data were processed. We calculate the denitrification rate by taking the average value to verify the correctness of the spray ammonia grid scheme.
3
Content available Modelling of ship’s trajectory planning in collision situations by hybrid genetic algorithm
Ni S., Liu Z., Cai Y., Wang X.
Polish Maritime Research
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2018
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nr 3
14--25
EN
Ship collision-avoidance trajectory planning aims at searching for a theoretical safe-critical trajectory in accordance with COLREGs and good seamanship. In this paper, a novel optimal trajectory planning based on hybrid genetic algorithm is presented for ship collision avoidance in the open sea. The proposed formulation is established based on the theory of the Multiple Genetic Algorithm (MPGA) and Nonlinear Programming, which not only overcomes the inherent deficiency of the Genetic Algorithm (GA) for premature convergence, but also guarantees the practicality and consistency of the optimal trajectory. Meanwhile, the encounter type as well as the obligation of collision avoidance is determined according to COLREGs, which is then considered as the restricted condition for the operation of population initialization. Finally, this trajectory planning model is evaluated with a set of test cases simulating various traffic scenarios to demonstrate the feasibility and superiority of the optimal trajectory.
4
Content available Estimation of vehicle sideslip angle via pseudo-multisensor information fusion method
Chen T., Chen L., Cai Y., Xu X.
Metrology and Measurement Systems
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2018
|
Vol. 25, nr 3
499--516
EN
This paper presents a novel sideslip angle estimator based on the pseudo-multi-sensor fusion method. The kinematics-based and dynamics-based sideslip angle estimators are designed for sideslip angle estimation. Also, considering the influence of ill-conditioned matrix and model uncertainty, a novel sideslip angle estimator is proposed based on the wheel speed coupling relationship using a modified recursive least squares algorithm. In order to integrate the advantages of above three sideslip angle estimators, drawing lessons from the multisensory information fusion technology, a novel thinking of sideslip angle estimator design is presented through information fusion of pseudo-multi-sensors. Simulations and experiments were carried out, and effectiveness of the proposed estimation method was verified.
5
Content available Evolution properties of multi-Gaussian Schell model beams propagating in uniaxial crystal orthogonal to the optical axis
Lu X., Shen Y., Zhu X., Zhao C., Cai Y.
Optica Applicata
|
2016
|
Vol. 46, nr 1
19--34
EN
An analytical formula for the multi-Gaussian Schell model is derived for the beam propagating in a uniaxial crystal orthogonal to the optical axis. The propagation properties of multi-Gaussian Schell model beams in a uniaxial crystal orthogonal to the optical axis is investigated by using the analytical formula. Some results are illustrated by numerical examples related to the propagation properties of multi-Gaussian Schell model beams. It is found that the propagation properties of the multi-Gaussian Schell model beams are very different from the propagation properties in the free space. They are closely related to the initial coherence and the ratio of the extraordinary and ordinary refractive indices. The results provide a way for studying the propagation properties of the multi-Gaussian Schell model beams in the uniaxial crystal orthogonal to the optical axis.
6
Content available Focusing properties of partially coherent dark hollow Gaussian beams through a thin lens system
Dong Y., Zhao C., Wang K., Zhao C., Cai Y.
Optica Applicata
|
2015
|
Vol. 45, nr 2
151--161
EN
This paper investigated the focal shift of partially coherent dark hollow Gaussian beams through a thin lens system. An analytic expression of the irradiance distribution of the focusing partially coherent dark hollow Gaussian beams in the back focal plane has been given by using the Collins formula. The focus shift of focused partially coherent dark hollow Gaussian beams in different parameters is studied in detail by numerical calculations. It is found that the absolute value of the focal shift of partially coherent dark hollow Gaussian beams decreases as the transverse coherence width or the order of the dark hollow Gaussian beams or a parameter of the dark hollow Gaussian beams increases.
7
Content available Ship Route Design for Avoiding Heavy Weather and Sea Conditions
Cai Y., Wen Y., Wu L.
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
|
2014
|
Vol. 8 no. 4
551--556
EN
This paper covers the current state of maritime oil transportation in the Baltic Sea and the development of oil transportation in the 2000s, as well as estimations of transported oil volumes in 2020 and 2030 in the Gulf of Finland. The scenarios were formulated on the basis of a current state analysis, energy and transportation strategies and scenarios and expert assessments. The study showed that the volumes of oil transportation in the Gulf of Finland will increase only moderately compared to the current status: 9.5-33.8 %, depending on the scenario. Green energy policy favours renewable energy sources, which can be seen in the smaller volumes of transported oil in the 2030 scenarios compared to the 2020 scenarios. In the Slow development 2020 scenario, oil transport volumes for 2020 are expected to be 170.6 Mt (million tonnes), in the Average development 2020 187.1 Mt and in the Strong development 2020 201.5 Mt. The corresponding oil volumes for the 2030 scenarios were 165 Mt for the Stagnating development 2030 scenario, 177.5 Mt for the Towards a greener society 2030 scenario and 169.5 Mt in the Decarbonising society 2030 scenario.
8
Content available remote Identifying priority areas for the conservation of ecosystem services using GIS-based multicriteria evaluation
Liu Y., Zhang H., Yang X., Wang Y., Wang X., Cai Y.
Polish Journal of Ecology
|
2013
|
Vol. 61, nr 3
415--430
EN
The rapid global urban growth poses a great risk to the ecosystem services which are vital to sustaining and fulfilling human life. As an essential part of Fuzhou eco-planning task in south-eastern China, we identified the priority conservation areas for ecosystem services to allow a sustainable urban expansion. We modeled and mapped five ecosystem services (carbon storage, timber production, water yield, water-quality improvement and sediment retention) using InVEST and proposed a definition of priority areas for the conservation of ecosystem services. Priority areas for individual ecosystem services showed that 24% of the region was needed to produce 26% of water yield. Between 6 and 17% of the region was required to conserve at least 20% of other four services, depending on the ecosystem service of interest. In addition, scenarios for multiple ecosystem services conservation were developed using the ordered weighted averaging (OWA) method, a multicriteria evaluation method, to take the tradeoffs among ecosystem services into account. The results showed that, along with the decrease of the OWA risk, the overall areas and the areas at both of the conservative levels dropped gradually. Furthermore, two efficiency indices were created to evaluate the performance of different OWA scenarios. Study results suggested that the efficiency of scenarios was associated with the conservation threshold and OWA risk, as well as the spatial correlation among ecosystem services. In sum, identifying priority areas for ecosystem services in a spatially explicit manner, and analyzing tradeoffs between them, can help make land use and natural resource decisions more effective and efficient.
9
Content available remote Quality evaluation of Yanghuo Sanqi tablet through a simultaneous determination of five major active flavonoids and three main saponins by HPLC-DAD-ELSD
Zhu F. X., Jia X. B., Cai Y., Chen Y.
Acta Chromatographica
|
2013
|
Vol. 25, no. 1
147--157
EN
Yanghuo Sanqi tablet (YST), combined prescription mainly derived from the leaves of herba epimedii and the roots of Panax notoginseng, is a traditional Chinese medicine (TCM). Flavonoids (icarrin, epimedin A, epimedin B, epimedin C, and baohuoside I) and saponins (notoginsenoside R1, ginsenoside Rgl, and ginsenoside Rbl) are considered as the main bioactive compounds of YST. However, there is no report on quality control of TCMs by simultaneous determination of above-mentioned flavonoids and saponins so far. In this work, for the first time, a high-performance liquid chromatography-diode array detector-evaporative light-scattering detector (HPLC-DAD-ELSD) method was developed to evaluate the quality of YST through a simultaneous determination of five major active flavonoids and three main saponins. Optimum separations were obtained with a Zorbax SB-C18 column by gradient elution with acetonitrile-water as the mobile phase. The drift tube temperature of ELSD was set at 105 °C, and the nebulizing gas flow rate was 2.5 L min-1. The fully validated method was successfully applied to quantify the eight bioactive components in three lot products. This simple, low-cost, and reliable HPLC-DAD-ELSD method provided a new basis for assessing the quality of traditional Chinese medicinal compound preparations (TCMCPs) consisting of many bioactive components.
10
Content available remote Quality evaluation of Yanghuo Sanqi tablet through a simultaneous determination of five major active Flavonoids and three main saponins by HPLC-DAD-ELSD
Zhu F. X, Jia X. B, Cai Y., Chen Y.
Acta Chromatographica
|
2012
|
Vol. 24, no. 4
667--677
EN
Yanghuo Sanqi tablet (YST), combined prescription mainly derived from the leaves of Herba epimedii and the roots of Panax notoginseng, is a traditional Chinese medicine (TCM). Flavonoids (icarrin, epimedin A, epimedin B, epimedin C, and baohuoside I) and saponins (notoginsenoside R1, ginsenoside Rgl, and ginsenoside Rbl) are considered as the main bioactive compounds of YST. However, there is no report on quality control of TCMs by simultaneous determination of above-mentioned flavonoids and saponins so far. In this work, for the first time, a high-performance liquid chromatography-diode array detector-evaporative light scattering detector (HPLC-DAD-ELSD) method was developed to evaluate the quality of YST through a simultaneous determination of five major active flavonoids and three main saponins. Optimum separations were obtained with a Zorbax SB-C18 column by gradient elution with acetonitrile-water as the mobile phase. The drift tube temperature of ELSD was set at 105 °C, and the nebulizing gas flow rate was 2.5 L min-1. The fully validated method was successfully applied to quantify the eight bioactive components in three lot products. This simple, low-cost, and reliable HPLC-DAD-ELSD method provided a new basis for assessing the quality of traditional Chinese medicinal compound preparations (TCMCPs) consisting of many bioactive components.
11
Content available remote Sensitivity-based stability evaluation of closed piping networks
Fu Y., Cai Y., Wu K.
TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk
|
2007
|
Vol. 11, No 3
197-202
EN
Aiming at a closed-loop water system of HVAC engineering, the authors put forward an evaluation method of systems' stability based on sensitivity. It has three evaluating indexes: [alfa] - the summation of flow changes in other subcircuits influenced by resistance change in a certain subcircuit [Beta] - the summation of flow changes in a certain sub circuit influenced by resistance changes in other subcircuits; [gamma] - average [Beta] (or [alfa]) value of each subcircuit, reflecting the strength of regulating interference between subcircuits. The method is used to analyze the stability of a reverse return system (RRS) and a direct return system (DRS). The DRS subcircuit farthest from the heat source and the middle RRS are the least stable. Stability of the whole RRS is inferior to that of the DRS.
12
Content available remote Forecasting the energy-saving benefits of variable-speed pumps
Fu Y., Cai Y., Wu K.
TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk
|
2006
|
Vol. 10, No 1
27-33
EN
By calculating the energy-saving benefits of a variable-speed pump, the relation between back pressure and energy-saving benefits is analyzed. Based on the energy-saving benefit calculation for four different pump types using a non-dimensional method, it is shown that when the non-dimensional back pressure, h, and the non-dimensional flow, Q, are equal, then the corresponding non-dimensional energy-saving benefit [omega] of variable-speed control are quite close each to other, thereby advancing a forecasting method of energy-saving benefits of variable-speed control. When the method is used to forecast the energy-saving benefits of pumps whose specific speed is between 15 and 190 and the flow - between 5 and 200 m3/h (subject to the condition h<; 0.9, Q> 0.5), the error will not exceed 6.55% and thus the method proves to be of reference value for the evaluation of the variable-speed energy-saving benefits of other pumps.
13
Content available remote Energy consumed by valves in conventional water systems and the application of a power-decentralization system
Fu Y., Cai Y., Zhang Z., Wu K.
TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk
|
2006
|
Vol. 10, No 3
311-320
EN
The power consumption by valves of a conventional (i.e. power-centralized) water system is analyzed on the example of a water heating system in order to evaluate the extent of energy savings achievable in a power-decentralized system. The configuration and appli-cation of a power-decentralized system is briefly discussed.
14
An adaptive robust observer for a class of uncertain systems
Luo J., Cai Y., Liu F.
Systems Science
|
2004
|
Vol. 30, no 3
69-75
EN
The problem of the robust adaptive observer for a class of uncertain systems with partially known nonlinear uncertainties is discussed. The proposed adaptive robust observer guarantees the observe error of the systems uniformly ultimately bounded. In contrast to some results in the control literature, the adaptive law for updating the estimate values of the unknown parameters is continuous. And the existence of the solutions to the resulting close-loop systems in the common sense can be guaranteed. Moreover, the proposed robust adaptive observer can be easily implemented in practical control due to its continuity. Finally, an illustrative example is given to demonstrate the utilization of the results.
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