Study on the safety speed of vehicle turning with considering the driving safety evaluation

Author(s):  
Qu Xian ◽  
Yu Feng ◽  
Zhang Jinlong ◽  
Xie Jun

Safety speeds estimation, as an indispensable link in the development of the aided or automatic drive, receives wide attention recently. Due to uncertain disturbances of vehicle driving, it is a challenging task to estimate the safety speed credibly. This work proposes a modified estimation approach to predict the turning safety speed by combining the static drive safety evaluation with the dynamic vehicle speed calculation. First, the driving safety state is evaluated considering the coupling of driver-vehicle-road-environment, where a comprehensive evaluation is obtained by combing the analytic hierarchy process and entropy weight analysis method. Then, a turning critical speed is calculated based on the vehicle driving dynamics considering both sideslip and rollover. The estimation of turning safety speed is achieved by modifying the critical speed with a safety correction factor obtained from the driving safety state evaluation. Finally, cases discussion on driving safety states evaluation, as well as the critical speed verification and safety speed analysis, are carried out. The results verify the validity of the driving safety state evaluation and critical speed calculation. The safety speeds have a reasonable safety margin according to the driving safety state evaluation. The maximum differences between the safety speeds and critical speeds are about 26.45% for buses and 26.39% for cars under low adhesion conditions, showing sufficient reliability for safety speed estimation.

Author(s):  
Yonghong Yang ◽  
Yu Chen ◽  
Zude Tang

Increasing traffic volume and insufficient road lanes often require municipal roads to be reconstructed and expanded. Where a road passes under a bridge, the reconstruction and expansion project will inevitably have an impact on the bridge. To evaluate the safety impact of road engineering projects on bridges, this paper evaluates the safety of the roads and ancillary facilities of highway bridges involved in municipal road engineering projects. Based on a comprehensive analysis of the safety factors of municipal roads undercrossing existing bridges, a fuzzy comprehensive analytic hierarchy process (AHP) evaluation method for the influence of road construction on the safety of existing bridges is proposed. First, AHP is used to select 11 evaluation factors. Second, the target layer, criterion layer, and index layer of evaluation factors are established, then a safety evaluation factor system is formed. The three-scale AHP model is used to determine the weight of assessment indexes. Third, through the fuzzy comprehensive AHP evaluation model, the fuzzy hierarchical comprehensive evaluation is carried out for the safety assessment index system. Finally, the fuzzy comprehensive evaluation method is applied to the engineering example of a municipal road undercrossing an existing expressway bridge. The comprehensive safety evaluation of the existing bridge reflects the practicability and feasibility of the method. It is expected that, with further development, the method will improve the decision-making process in bridge safety assessment systems.


2021 ◽  
Vol 236 ◽  
pp. 01024
Author(s):  
Bo Wu

In order to study the influence of distributed power access on the security state of distribution network, a comprehensive evaluation method for the security state of distribution network including distributed power access was proposed.Based on the output model and load model of photovoltaic power supply, the security situation assessment index system of distributed power supply access distribution network is established. Then combined with fuzzy analytic hierarchy process and entropy weight method, the composite weight of each index is obtained, and the combined weight is optimized based on chi-square distance. Finally, the evaluation method based on ER algorithm (Evidential Reasoning) is proposed. Simulation results verify the effectiveness and accuracy of the proposed method.


2014 ◽  
Vol 551 ◽  
pp. 722-726
Author(s):  
Xin Cao

In order to evaluate coaches, this paper established the model of comprehensive evaluation based on analytic hierarchy process (AHP). Firstly, I establish the hierarchical structure of the system; Secondly, for researching the influence of time line horizon in analysis, I divided coaches into several groups by their career time and calculated the weights of indicators of each group using entropy weight method; Finally, calculate the weight between the criteria layer and objective layer. Female coach data is difficult to find, so I select 100 college basketball male coach data. Put the data into model and get a score. The score showed the final result which can give us a sort of reasonable coach list. This model can reduce the influence of different time periods for evaluation of the coach.


2019 ◽  
Vol 136 ◽  
pp. 01030
Author(s):  
Xi Wang ◽  
Wei Wang ◽  
Hao Xu ◽  
Qiang Ye ◽  
Shi Chen ◽  
...  

In this paper, the Market-oriented Operations Strategy of CCHP are analysed, from the perspective of construction mode, operating mode and charging mode. On this basis, a three-dimensional indexes system is established, and combining the entropy weight method with Analytic Hierarchy Process as a comprehensive evaluation method to evaluate the different market-oriented strategies of CCHP. Finally, the empirical analysis of the commercial building in southwest China shows that the market-oriented strategy of CCHP can bring more benefits to market participants when it has high applicability and great practical value.


2014 ◽  
Vol 651-653 ◽  
pp. 885-890
Author(s):  
Huai Liang Zheng ◽  
Ri Xin Wang ◽  
Min Qiang Xu

Based on the gearbox as the research object, we discussed the problem: how to confirm every part’s weight when assess gearbox’s state by fuzzy comprehensive evaluation method. Contraposing the main problem of the weight-fixed Analytic Hierarchy Process (AHP) that ignoring every part’s fault degree in the process of evaluation, a variable weight method is proposed base on the rate of fault degree contribution. And to a state known gearbox, the weight of each part in the whole gearbox assessment is confirmed by the AHP and the variable weight method respectively. The comparison of the two assessment results shows that the result get by the variable weight method is more close to the gearbox’s real state, so this method is more accurate. What’s more this method is very simple, and can be used in real project.


2016 ◽  
Author(s):  
H. Z. Su ◽  
M. Yang ◽  
Z. P. Wen

Abstract. High rocky slope is an open complex giant system with contradiction among different influencing factors and coexistence of qualitative and quantitative information. This study presents a comprehensive intelligent evaluation method of high rocky slope safety by an integrated analytic hierarchy process, extension matter element model and entropy-weight to assess the safety behavior of the high rocky slope. The proposed intelligent evaluation integrates subjective judgments derived from the analytic hierarchy process with the extension matter model and entropy-weight into a multiple indexes dynamic safety evaluation approach. A combining subjective and objective comprehensive evaluation process, a more objective manner through avoiding subjective effects on the weights and a qualitative safety assessment and quantitative safety amount are presented in the proposed method. The detailed computational procedures were also provided to illustrate the integration process of the above methods. Safety analysis of one high rocky slope is conducted to illustrate that this approach can adequately handle the inherent imprecision and contradiction of the human decision-making process and provide the flexibility and robustness needed for the decision maker to better monitor the safety behavior of high rocky slope. This study was the first application of proposed integrated evaluation method to safety assessment of high rocky slope, which also indicated that it can also be applied to other similar problems.


2010 ◽  
Vol 163-167 ◽  
pp. 2738-2741 ◽  
Author(s):  
Xiao Fei Liang ◽  
Ying Chun Fu ◽  
Yue Xu

Connected with the practical construction and considering Structural properties of single-tower self-anchored suspension bridge, the multi-level safety evaluation model is established according to the main risk factor and weighting rate of risk factor is analyzed by the analytic hierarchy process. A safety assessment method with qualitative analysis and quantitative analysis is proposed based on the grey theory and fuzzy mathematics theory for the practical problem of multi-index comprehensive evaluation, and risk ranking is given.


2010 ◽  
Vol 20-23 ◽  
pp. 196-201
Author(s):  
Ge Ning Xu ◽  
Fan Jiang

By combined fuzzy comprehensive evaluation with AHP (Analytic Hierarchy Process) together, a safety assessment model for overhead traveling crane is set up in regard to deficiency of safety assessment method for crane at present, which can evaluate safety of overhead traveling crane in-service qualitatively and quantitatively. Through a safety analysis and assessment on general overhead traveling crane, the result of assessment is in accord with the practical situation of overhead traveling crane. It can reflect more fully the safety of the whole crane system and the influence and level of each factor to whole crane system safety, witch an effective synthetic evaluation method is put forward for the safety evaluation of crane.


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