Weibull Modelling of the Operational Costs of a Start-Stop and Idling Traffic Drive Decision Applications

ABSTRACT

In this study, start-stop and idling time traffic data are presented from the results of traffic time experimental investigation and are thereafter analyzed using appropriate mathematical models to generate start-stop/idling failure time data, then properly fitted with a Weibull function to effectively represent failure and survival probability distribution alongside failure rate of the assumed series connected start-stop system components (75amp flooded lead acid battery, DC starter motor and the ignition system) and the idling system components (failure of one component, is the failure of the entire system), hence the need to determine the distributions parameters, for accurate representation. A failure plus right-censored and all right-censored data sets for both drive options were presented for a Bayesian Weibull parameters estimation and subsequent operational costs analysis which reported the following costs: the starter system operating cost, Css = ₦91,763.88, that of the idling cost operation Cis = ₦102,517.30, with start-stop cost savings of CS = ₦ 10753.30 or 10.49%. The operating costs for the start-up system for the all right-censored failure dataset gives; Css = ₦575.24 and that of the idling operation is Cis= ₦2,411.25, with a cost savings of CS = ₦1,836.01 (76.14%) of the start-stop system over that of idling resulting from the idling system higher failure probability and fuel consumption cost. The conclusion drawn from the study is that, the start-stop traffic drive decision is more economical about the determined traffic time, although for newly installed.

Keywords — Start-Stop, Idling, Bayesian, Right-Censored, Hasting Algorithm, Normalization

Constant, Posterior Probability and Failure Data.