Control apparatus for electric vehicle, control system for electric vehicle, and control method for electric vehicle

A braking system, comprising:

• an electric vehicle including
• a front motor configured to output a torque to a front wheel of the electric vehicle by supply and reception of power to and from a power source, and
• a rear motor configured to output a torque to a rear wheel of the electric vehicle by supply and reception of power to and from the power source,
• a brake apparatus capable of providing a frictional braking force to each of the front wheel and the rear wheel, the braking system being configured to:
• calculate a regenerative braking force to be generated on the front motor and the rear motor based on a request braking force requested to the electric vehicle;
• reduce the regenerative braking force based on a power limit on the power source;
• and
• output an instruction for generating the frictional braking force according to a regenerative braking force reduction amount, which is an amount of a reduction in the regenerative braking force, to the brake apparatus, and
• a control apparatus, which is configured to
• reduce the regenerative braking force in the electric vehicle in such a manner that a regenerative braking force reduction ratio, which is a ratio of the regenerative braking force reduction amount of the rear motor to the regenerative braking force reduction amount of the front motor, matches a frictional braking force front-rear ratio, which is a ratio of the frictional braking force of the rear wheel to the frictional braking force of the front wheel;
• calculate the regenerative braking force to be generated on each of the front motor and the rear motor based on the request braking force and a front wheel load and a rear wheel load of the electric vehicle;
• calculate an estimated lateral acceleration to be generated on the electric vehicle based on a speed of the electric vehicle and a steering angle;
• acquire a detected lateral acceleration from an acceleration sensor configured to detect an acceleration of the electric vehicle;
• select an acceleration having a larger absolute value as a selected lateral acceleration from the estimated lateral acceleration and the detected lateral acceleration;
• calculate an estimated longitudinal acceleration to be generated on the electric vehicle based on an instruction for a torque to be generated on an axle of the electric vehicle, acquire a detected longitudinal acceleration from the acceleration sensor;
• select an acceleration having a larger absolute value as a selected longitudinal acceleration from the estimated longitudinal acceleration and the detected longitudinal acceleration;
• and
• calculate the front wheel load and the rear wheel load based on the selected lateral acceleration and the selected longitudinal acceleration.