Vehicle steering control system

A vehicle steering control system for a vehicle, comprising:

• a steering system as a control target, configured to receive a plurality of m inputs and provide a plurality of n outputs based on the plurality of m inputs received, wherein each of m and n is a natural number that is more than one, m being equal to n, the plurality of m inputs including operation quantities, the plurality of n outputs including control quantities;
• a plurality of feedback controllers, each of which is configured to calculate an operation quantity of the operation quantities based on a difference between (i) a target value, which is generated by a target value generator, the target value corresponding to a control quantity of the control quantities, and (ii) a current value of an output of the plurality of n outputs provided by the control target;
• and
• a non-interference controller provided between (i) the plurality of feedback controllers and (ii) the control target, the non-interference controller being configured to execute a non-interference control to reduce influence due to mutual interference between the outputs provided by the control target,
• wherein:
• the plurality of n outputs provided by the control target include three control quantities that are (i) a steering angle, (ii) a yaw angle velocity, and (iii) a lateral acceleration, the three control quantities being vehicle properties of vehicle motions generated based on a driver's steering torque;
• a plurality of combinations of the plurality of m inputs and the plurality of n outputs in the control target are designated by the vehicle steering control system;
• and
• the non-interference control by the non-interference controller and the feedback control by the feedback controllers are configured to be executed with respect to each of the designated combinations of the plurality of m inputs and the plurality of n outputs,
• wherein:
• the control target includes a variable gear transfer steering motor which controls an actual steering angle of a front wheel, while one of the designated combinations is of (i) a motor voltage of the variable gear transfer steering motor that serves as one of the plurality of m inputs and (ii) the steering angle of the vehicle that serves as one of the plurality of n outputs;
• the control target includes an electric power steering motor which assists a steering force by a driver, while one of the designated combinations is of (i) a motor voltage of the electric power steering motor that serves as one of the plurality of m inputs and (ii) the yaw angle velocity of the vehicle that serves as one of the plurality of n outputs;
• and
• the control target includes an active rear steering motor which controls an actual steering angle of a rear wheel, while one of the designated combinations is of (i) a motor voltage of the active rear steering motor that serves as one of the plurality of m inputs and (ii) the lateral acceleration of the vehicle that serves as one of the plurality of n outputs.