Abstract
Research and/or Engineering Questions/Objective
The local driving cycle has great effect on fuel economy, parameters matching and control strategy for hybrid electric city bus. The driving cycles quoted in Chinese national standard are not consistent with the real Xi'an driving. Thus, the objective of this paper is to develop transient driving cycle and modal driving cycle for Xi'an hybrid electric city bus by means of cluster analysis and piecewise linear regression analysis.
Methodology
Based on driving condition data of Xi'an hybrid electric city bus, clustering analysis method is used to develop the transient driving cycle. And a weighted index method is applied to eliminate fluctuations effect. A piecewise linear regression method is applied to develop the modal driving cycle from transient driving cycle. statistics analysis and simulation based on advisor are used to testify transient and modal driving cycles.
Research results
In the paper, Xi'an hybrid electric bus transient and modal driving cycles are developed. Three typical driving cycle conditions (crowded traffic, normal traffic and smooth traffic) are identified. Statistics analysis and simulation results show that these two driving cycles can reflect the actual operation state for hybrid electric city bus, which supplies the design reference for parameters matching and control strategy designing. And the driving cycles quoted in Chinese national standard deviate from the real word driving cycle.
Limitations of this study
Transient and modal driving cycles are verified only through statistics analysis and simulation test. Real road test are not carried to testify them and will be done in future.
What does the paper offer that is new in the field including in comparison to other work by the authors?
For transient driving cycle, a index weighting method is used to eliminate the error caused by the influence of fluctuation. And a piecewise linear regression analysis is used to develop the modal driving cycle from the transient driving cycle.
Conclusions
The Xi'an hybrid electric city bus transient driving cycle and modal driving cycle are developed in this paper by means of cluster analysis and piecewise linear regression analysis. The effectiveness of these two driving cycles are verified by statistics analysis and simulation results. These two driving cycle can reflect the real word driving cycle and can be used to match parameters and design control strategy for Xi'an hybrid electric city bus.
Key Words : Hybrid electric city bus; Cluster analysis; Piecewise regression analysis; Driving cycle;