Patent attributes
During vehicle drive under an EV mode, a battery charge state SOC becomes smaller than a SOC(L) at time t0. As a result, EV→HEV mode change is carried out. After time t1, deceleration is desired, and an accelerator opening APO is kept at 0. At time t3, the SOC increases and becomes greater than or equal to a SOC(H) by the HEV mode. In this case, after time t1 of release of an accelerator pedal, the SOC(H) is cleared at time t2 at which a vehicle operating condition is judged to be a low load drive condition in which a motor/generator performs regenerative braking. By making a judgment of HEV→EV mode change based on the SOC(L) instead of the SOC(H), the HEV→EV mode change is carried out before time t3. A regenerative braking time Δt with the engine dragged is therefore shortened, and a regenerative braking time with no-engine drag can be correspondingly lengthened, improving an energy recovery performance.
