Control system for hybrid vehicle

A control system for a hybrid vehicle comprising an engine that generates a travel driving force of the hybrid vehicle;

• a motor capable of performing a powering operation and a regenerative operation;
• a first clutch provided between the engine and the motor and that is switched between an engaged state of mutual engagement between the engine and the motor and a disengaged state of releasing the engagement;
• and an axle provided between the motor and driving wheels of the hybrid vehicle, the control system comprising:
• a hydraulic friction brake system that distributes a braking force to the driving wheels in response to driver's operating a brake pedal;
• and
• a control unit capable of performing cooperative regenerative braking control for braking the hybrid vehicle by cooperation between distribution of the braking force by the hydraulic friction brake system and application of a regenerative braking torque to the driving wheels by controlling the motor to perform the regenerative operation in a state of releasing the first clutch during deceleration of the vehicle when operating the brake pedal, wherein
• when start of the engine is requested during the cooperative regenerative braking control, the control unit performs:
• a first process of transitioning braking by the cooperative regenerative braking control to braking only by the hydraulic friction brake system;
• a second process of raising an output revolution speed of the engine by controlling the motor to perform either the powering operation or the regenerative operation while initiating engagement of the first clutch after completion of transitioning to the braking only by the hydraulic friction brake system;
• and
• a third process of controlling the engine to resume operating at a timing after the output revolution speed of the engine increases to match an output revolution speed of the motor after the engagement of the first clutch is initiated.