A Harmonic Controller of Engine Speed Oscillations for Hybrid Vehicles

In conventional internal combustion engines, the periodic fuel combustion in cylinders and oscillating masses result in pulsating engine torque. In hybrid powertrains, the electrical motor can be used to control such pulsations. The main originality of this paper is to present an efficient harmonic controller synchronized with the engine speed: the feedback law controls the Fourier parameters of the command. For time-variation of the engine speed, the adaptation of the harmonic controller ensures the convergence of the command. Conditions of stability are given, and the robustness of the approach is presented. Simulation shows that the undesirable harmonics of engine speed oscillations are perfectly rejected in spite of engine speed variation.