A new methodology to evaluate the energy consumption and air pollution by heavy-duty vehicles during use is presented. The core is the development of test cycles that are a simulation of the traffic forced elements of operation in reality, thus not imposing vehicle forced nor driver forced elements. The test cycles are distance based, and do not impose a fully specified speed profile, but only maximum speed levels, or goal-speeds, at each position. This allows testing of different styles of driving behaviour and different vehicle loading conditions using the same basic test cycles. The choice for this kind of test cycle is based on the modal analyses of the fuel consumption and mass emissions figures of CO2, CO, THC and NOx recorded with a time resolution of one second by on-board measurements. This modal approach is illustrated for the case of a diesel city-bus. (A)
Abstract