Abstract: It is one of the important requisites for active vibration isolation of a vehicle powertrain mounting system to accurately acquire the inertia properties and the unbalanced forces of the powertrain. Based on the damping controllability of the magneto-rheological damper and the relativity between the unbalanced forces and the rotary speed of the engine, a new method for identifying inertia parameters and unbalanced forces of engine is proposed by measuring engine mount accelerations and support reactions on different damper coefficients. Compared with traditional methods, this method has the merits of targeted, repeated test without motor lifting, all parameters identified simultaneously. The effectiveness of this method is verified by the finite element numerical simulation data of a simple modeland the on-site measured data of a four-cylinder four-stroke powertrain. Results show that the recognition accuracy of inertia parameters meets the engineering needs and the unbalance force identification results are more realistic compared to the simplified theoretical formula.

Key words: Engine, Moment of inertia, Physical parameter identification, Vibration isolation test