Controller, vehicle, and control method

A vehicle comprising:

• an electric motor that generates an electric driving force for propelling the vehicle;
• an engine that generates an engine driving force for propelling the vehicle;
• an acquisition part that acquires an oxygen concentration of exhaust from the engine;
• and
• a drive control part that reduces an injection amount of fuel injected into a cylinder of the engine and increases an electric driving force, from among the engine driving force and the electric driving force for propelling the vehicle, when the oxygen concentration is lower than an oxygen threshold value in comparison to when the oxygen concentration is equal to or higher than the oxygen threshold value;
• wherein the drive control part:
• identifies a rotational speed of the engine corresponding to a current traveling speed or a target speed of the vehicle,
• identifies a first engine torque corresponding to the identified rotational speed when it is determined that the oxygen concentration is equal to or higher than the oxygen threshold value by referencing a first map indicating a relationship between an engine torque and the rotational speed of the engine when the oxygen concentration is equal to or higher than the oxygen threshold value,
• identifies a first injection amount on the basis of the identified first engine torque,
• identifies a second engine torque corresponding to the identified rotational speed of the engine when it is determined that the oxygen concentration is lower than the oxygen threshold value by referencing a second map indicating a relationship between an engine torque and the rotational speed of the engine when the oxygen concentration is lower than the oxygen threshold value, and
• identifies a second injection amount which is smaller than the first injection amount, on the basis of the identified second engine torque.

A control method comprising computer-implemented steps of:

• acquiring an oxygen concentration of exhaust from an engine;
• reducing an injection amount of fuel injected into a cylinder of the engine and increasing an electric driving force generated by an electric motor, from among the electric driving force generated by the electric motor and an engine driving force generated by the engine for propelling the vehicle, when the oxygen concentration is lower than an oxygen threshold value in comparison to when the oxygen concentration is equal to or higher than the oxygen threshold value;
• identifying a rotational speed of the engine corresponding to a current traveling speed or a target speed of the vehicle;
• identifying a first engine torque corresponding to the identified rotational speed when it is determined that the oxygen concentration is equal to or higher than the oxygen threshold value by referencing a first map indicating a relationship between an engine torque and the rotational speed of the engine when the oxygen concentration is equal to or higher than the oxygen threshold value;
• identifying a first injection amount on the basis of the identified first engine torque;
• identifying a second engine torque corresponding to the identified rotational speed of the engine when it is determined that the oxygen concentration is lower than the oxygen threshold value by referencing a second map indicating a relationship between an engine torque and the rotational speed of the engine when the oxygen concentration is lower than the oxygen threshold value;
• and
• identifying a second injection amount which is smaller than the first injection amount, on the basis of the identified second engine torque.