Abstract
We developed an estimation model for the environmental impact of automobiles that has high resolution in terms of time and space. The scheme of the model framing is shown below.
(1) As a unit of running, the pair of the idling section, showing time transfer, and the running section (from start to stop), showing spatial transfer, was defined as a trip segment.
(2) In each mode (idling, acceleration, cruising, and deceleration) of a trip segment unit, running characteristic values (velocity, acceleration, etc.) and the amount of environmental impact (EI) was calculated. Regression analysis was applied to these values and EI was expressed with the following formula for each vehicle.
El=C×f (running characteristic values) C: paramcter speculiar to vehicles
(3) The parameters C were generalized with the item value of the vehicles, and a general-purpose model that estimates EI from vehicle speed data was created.
EI=α(item value of vehicles)β×f (unning characteristic values)
α, β: regression coefficient
item value of vehicles: weight of vehicle, displacement
The defining feature of this model is its ability to estimate the amount of environmental impact from an automobile by an indirect technique using the running records of a digital tachometer, etc., without using a chassis dynamometer. Because the estimation method is based on running characteristics such as acceleration, the model can clearly reflect the difference in each driver's operating method.
This paper showed the scheme of the model framing for heavy-duty diesel vehicles that meets the current Japanese short-term and long-term standards for emissions, and the model was verified by observation.
