Steering assist apparatus for vehicle

A steering assist apparatus for a vehicle, which is to be applied to the vehicle comprising a steering device,

• the steering device comprising:
• a steering wheel to be operated by a driver;
• steered wheels;
• and
• a transmission device configured to transmit a force and a displacement relating to steering between the steering wheel and the steered wheel,
• the steering assist apparatus comprising:
• an adjustment force applying device configured to apply an adjustment force for adjusting a force relating to the steering to the transmission device;
• a control device configured to control the adjustment force to be applied by the adjustment force applying device to the transmission device;
• a steering angle detection device configured to detect a steering angle;
• and
• a steering torque detection device configured to detect a steering torque,
• wherein the control device is configured to acquire a steering angular velocity, a derivative of the steering angular velocity, and a derivative of the steering torque, calculate, assuming the steering wheel, the transmission device, the adjustment force applying device, and the steered wheel as a steering system, a change rate of an energy of the steering system based on a product of the steering angular velocity and the derivative of the steering angular velocity, a product of the steering angular velocity and the steering torque, and a product of the steering angle and the derivative of the steering torque, and control the adjustment force based on the change rate of the energy of the steering system.