Steering angle control apparatus and steering angle control method

A steering angle control apparatus configured to control a steering angle of a vehicle such that the vehicle travels following a target route, the steering angle control apparatus comprising:

• a microprocessor;
• and
• a memory connected to the microprocessor, wherein
• the microprocessor is configured to perform:
• estimating a second vehicle state quantity not acquired by a sensor of the vehicle, based on a first vehicle state quantity acquired by the sensor, among vehicle state quantities indicating a motion state of the vehicle;
• predicting, up to a predetermined time ahead, a behavior of the vehicle including deviations in a position and a direction of the vehicle with respect to the target route, based on the first vehicle state quantity, the second vehicle state quantity, and information indicating the target route;
• and
• optimizing a target steering angle by using a result of the predicting, wherein
• the microprocessor is configured to perform:
• the estimating including estimating using a first vehicle model modeling a relationship between the first vehicle state quantity and the second vehicle state quantity, and vehicle characteristic information regarding a motion characteristic of the vehicle;
• the predicting including predicting, up to the predetermined time ahead, the behavior using a prediction model including a second vehicle model modeling a relationship between the first vehicle state quantity and the second vehicle state quantity, and the vehicle characteristic information;
• the state estimation model and the prediction model have different methods of discretization;
• and
• information regarding the steering angle as the first vehicle state quantity is input in different formats to the first vehicle model and the second vehicle model.