Steering control device

A steering control device configured to operate a motor mechanically connected to an operation member to be operated by a driver to steer a vehicle, wherein

• the motor is a drive source for a plant mounted on the vehicle,
• the steering control device is configured to perform a torque feedback process, an operation process, and a characteristic change process,
• the torque feedback process includes a process of calculating a manipulated variable for controlling steering torque to target steering torque by feedback control,
• the steering torque is torque input to the operation member,
• the operation process is a process of operating a drive circuit for the motor based on the manipulated variable,
• the process of calculating the manipulated variable includes:
• a process of calculating a torque proportional output value of a proportional element;
• and
• a process of calculating the manipulated variable based on output values including the torque proportional output value,
• the torque proportional output value is a value obtained by multiplying a difference between the steering torque and the target steering torque by a torque proportional gain, and
• the characteristic change process includes a process of changing a response characteristic of the feedback control in the torque feedback process by changing the torque proportional gain according to a plant state of the plant.

A steering control device configured to operate a motor mechanically connected to an operation member to be operated by a driver to steer a vehicle, wherein

• the motor is a drive source for a plant mounted on the vehicle,
• the steering control device is configured to perform a torque feedback process, an operation process, and a characteristic change process,
• the torque feedback process includes a process of calculating a manipulated variable for controlling steering torque to target steering torque by feedback control,
• the steering torque is torque input to the operation member,
• the operation process is a process of operating a drive circuit for the motor based on the manipulated variable,
• the process of calculating the manipulated variable includes:
• a process of calculating a torque derivative output value of a derivative element;
• and
• a process of calculating the manipulated variable based on output values including the torque derivative output value,
• the torque derivative output value is a value obtained by multiplying a first-order time derivative of a difference between the steering torque and the target steering torque by a torque derivative gain, and
• the characteristic change process includes a process of changing a response characteristic of the feedback control in the torque feedback process by changing the torque derivative gain according to a plant state of the plant.