HYBRID ROAD GRADE DETERMINATION SYSTEM

摘要

A method of regulating operation of a hybrid vehicle traveling on a surface having a grade includes determining a drive force of the hybrid vehicle, calculating a brake pressure value and determining whether a grade freeze condition exists based on the brake pressure value. The method further includes calculating a grade value of the surface based on the drive force when the freeze condition does not exist and regulating operation of the hybrid vehicle based on the grade value.