Steering intention determination device, vehicle control device, steering assist device, and steering assist system

1. A steering intention determination device comprising:

an electronic control unit (ECU) programmed to:

calculate a steering type discrimination value showing a driver's steering type with respect to a steering wheel based on a product of a steering angular velocity and a steering torque during a driver's steering operation at the steering wheel and a product of a steering angle and a time differential value of the steering torque during the driver's steering operation; and

determine that the driver has a turn-and-steer steering intention in a case where the steering type discrimination value is equal to or greater than a predetermined value, determine that the driver has a steering holding intention in a case where the steering type discrimination value is less than the predetermined value and an absolute value of the steering angular velocity is less than a predetermined angular velocity, and determine that the driver has a switchback steering intention in a case where the steering type discrimination value is less than the predetermined value and the absolute value of the steering angular velocity is equal to or greater than the predetermined angular velocity; and

control a vehicle based on the driver's steering intention.

2. The steering intention determination device according to claim 1 ,

wherein the ECU is further programmed to determine that the driver's steering intention is the steering holding intention during straight driving if the absolute value of the steering angle is less than a predetermined angle and determines that the driver's steering intention is the steering holding intention during turning if the absolute value of the steering angle is equal to or greater than a predetermined angle in a case where it is determined that the driver has the steering holding intention.

3. A vehicle control device comprising:

an electronic control unit (ECU) programmed to:

calculate a steering type discrimination value showing a driver's steering type with respect to a steering wheel based on a product of a steering angular velocity and a steering torque during a driver's steering operation at the steering wheel and a product of a steering angle and a time differential value of the steering torque during the driver's steering operation;

determine that the driver has a turn-and-steer steering intention in a case where the steering type discrimination value is equal to or greater than a predetermined value, determine that the driver has a steering holding intention in a case where the steering type discrimination value is less than the predetermined value and an absolute value of the steering angular velocity is less than a predetermined angular velocity, and determine that the driver has a switchback steering intention in a case where the steering type discrimination value is less than the predetermined value and the absolute value of the steering angular velocity is equal to or greater than the predetermined angular velocity; and

control on a vehicle side based on the driver's steering intention.

4. The vehicle control device according to claim 3 ,

wherein the ECU is further programmed to determine that the driver's steering intention is the steering holding intention during straight driving if the absolute value of the steering angle is less than a predetermined angle, and determines that the driver's steering intention is the steering holding intention during turning if the absolute value of the steering angle is equal to or greater than the predetermined angle, in a case where it is determined that the driver has the steering holding intention.

5. The vehicle control device according to claim 3 ,

wherein the amount of change of a turning state quantity with respect to the amount of change of the steering angle is allowed to be greater in a case where it is determined that the driver's steering intention is the turn-and-steer steering intention than in a case where it is determined that the driver's steering intention is the steering holding intention.

6. The vehicle control device according to claim 3 ,

wherein the ECU is further configured to set the amount of change of a turning state quantity with respect to the amount of change of the steering angle in accordance with the turning state quantity and a vehicle characteristic with respect to the steering angle at the point in time of switching from the steering holding intention to the switchback steering intention in a case where it is determined that the driver's steering intention is the switchback steering intention.

7. The vehicle control device according to claim 3 ,

wherein the ECU is further programmed to allow an assist torque of an electric power steering device to be greater in a case where it is determined that the driver's steering intention is the turn-and-steer steering intention than in a case where it is determined that the driver's steering intention is the steering holding intention.

8. The vehicle control device according to claim 3 ,

wherein the ECU is further configured to set the amount of change of an assist torque of the electric power steering device with respect to the amount of change of the steering angle in accordance with a turning state quantity and a vehicle characteristic with respect to the steering angle at the point in time of switching from the steering holding intention to the switchback steering intention in a case where it is determined that the driver's steering intention is the switchback steering intention.

9. A steering assist device comprising:

an ECU configured to:

calculate a discrimination value based on a product of a steering angular velocity of a steering wheel and a steering torque relating to the steering wheel and a product of a steering angle of the steering wheel and a time differential value of the steering torque relating to the steering wheel and calculate an assist torque based on the discrimination value; and

assist the steering wheel based on the assist torque.

10. A steering assist system comprising:

a first electronic control unit (ECU) programmed to (i) calculate a discrimination value based on a product of a steering angular velocity of a steering wheel and a steering torque relating to the steering wheel and a product of a steering angle of the steering wheel and a time differential value of the steering torque relating to the steering wheel and (ii) determine a steering type based on the discrimination value; and

a second ECU to control on a vehicle side based on the steering type determined by the first ECU,

wherein the steering type includes a first steering type in which the steering wheel is turned and steered, a second steering type in which the steering angle of the steering wheel is held, and a third steering type in which the steering wheel is switched back, and

wherein the first ECU is further programmed to determine that the steering type is the first steering type in a case where the discrimination value is equal to or greater than a predetermined value, determine that the steering type is the second steering type in a case where the discrimination value less than the predetermined value and an absolute value of the steering angular velocity is less than a predetermined value, and determine that the steering type is the third steering type in a case where the discrimination value is less than the predetermined value and the absolute value of the steering angular velocity is equal to or greater than the predetermined value.