US Patent 9533677 Method of transitioning among shift schedules

A hybrid electric vehicle having a discrete ratio transmission shifts according to distinct shift schedules in various operating modes. For example, different shift schedules may be used for operating with the engine off, operating with the engine running, and regenerative braking. When the vehicle transitions from one mode to another, the new shift schedule may schedule a shift that the driver would not expect. To avoid annoying the driver, a control strategy inhibits the shift until either the old strategy would also schedule a shift or a customer event occurs.