Research on a diesel HCCI engine assisted by an ISG motor

► We developed hybrid engine by adopting ISG motor and HCCI-CI combined combustion. ► We improved fuel economy of diesel HCCI by using ISG assistance. ► ISG motor dynamic torque compensation improved HCCI transient performance. ► We developed ISG assisted HCCI-CI transition control strategy. ► We developed a high-efficient braking energy regeneration strategy.