Driving assist apparatus, driving assist method, and driving assist system

1. A driving assist apparatus comprising:

a standard running route acquisition portion configured to acquire a standard running route calculated based on curve information ahead of a vehicle that is acquired by at least one of a camera, a GPS, and a map database; and

an actuator control output portion configured to acquire a standard vehicle motion amount when the vehicle runs the standard running route, including a standard yaw rate, a required steering angle, and an appropriate vehicle body speed, calculate an instruction that guides a current vehicle motion amount of the vehicle toward the standard vehicle motion amount based on the standard vehicle motion amount and the current vehicle motion amount, including a current vehicle body speed and a current steering angle of a steering wheel, and output the instruction to an actuator portion, including a steering assist apparatus capable of changing a steering angle, a driving apparatus configured to provide a driving torque to a driving wheel of the vehicle, and a brake apparatus capable of braking the vehicle, configured to provide at least one of a curving force and a braking force to the vehicle,

wherein the actuator control output portion acquires the required steering angle for running the standard running route at the current vehicle body speed and the appropriate vehicle body speed at which a lateral acceleration matches or falls below a predetermined value when the vehicle runs the standard running route, calculates an assist torque output instruction reference value for providing a steering angle change amount that makes the current steering angle closer to the required steering angle to the steering wheel and a torque output instruction reference value for providing a driving torque reduction amount that makes the current vehicle body speed closer to the appropriate vehicle body speed to the driving wheel, acquires the standard yaw rate generated when the vehicle runs the standard running route, calculates a brake output instruction reference value for generating a yaw moment that makes a yaw rate acquired based on the current vehicle body speed and the current steering angle closer to the standard yaw rate on the vehicle, calculates a brake output instruction by multiplying the brake output instruction reference value by a brake moment amount weight which reduces as the assist torque output instruction reference value or the torque output instruction reference value increases, and outputs an assist torque output instruction based on the assist torque output instruction reference value, a torque output instruction based on torque output instruction reference value, and the brake output instruction to the steering assist apparatus, the driving apparatus, and the brake apparatus, respectively.

2. The driving assist apparatus according to claim 1 , wherein the brake output instruction is an instruction for generating the yaw moment on the vehicle by providing a braking torque to one or both of rear wheels of the vehicle.

3. The driving assist apparatus according to claim 1 ,

wherein the assist torque output instruction is calculated by multiplying the assist torque output instruction reference value by an assist torque correction coefficient weight which reduces as the brake output instruction reference value or the torque output instruction reference value increases.

4. The driving assist apparatus according to claim 1 ,

wherein the torque output instruction is calculated by multiplying the torque output instruction reference value by an engine torque correction coefficient weight which reduces as the brake output instruction reference value or the assist torque output instruction reference value increases.

5. The driving assist apparatus according to claim 1 , wherein the actuator control output portion gradually reduces the instruction to output to the actuator portion to zero when a failure has occurred in the at least one of a camera, a GPS, and a map database.

6. The driving assist apparatus according to claim 1 , wherein the actuator control output portion does not output the instruction to the actuator portion when a difference of the current vehicle motion amount from the standard vehicle motion amount is smaller than a predetermined value.

7. The driving assist apparatus according to claim 1 , wherein the actuator control output portion calculates an instruction that guides the motion amount of the vehicle toward the standard vehicle motion amount to a higher degree when a driver is performing a driving operation in a direction for making the motion amount of the vehicle closer to the standard vehicle motion amount than when the driver is performing the driving operation in a direction for making the vehicle motion amount farther away from the standard vehicle motion amount.

8. The driving assist apparatus according to claim 7 , wherein the actuator control output portion does not guide the motion amount of the vehicle toward the standard vehicle motion amount when the driver is performing the driving operation in the direction for making the motion amount of the vehicle farther away from the standard vehicle motion amount.

9. A driving assist method comprising:

a step of acquiring a standard running route calculated based on curve information ahead of a vehicle; and

a step of acquiring a current vehicle body speed and a current steering angle of a steering wheel as a current vehicle motion amount,

wherein a standard vehicle motion amount when the vehicle runs the standard running route is a standard yaw rate, a required steering angle, and an appropriate vehicle body speed,

the method further comprising:

a step of acquiring the required steering angle for running the standard running route at the current vehicle body speed and the appropriate vehicle body speed at which a lateral acceleration matches or falls below a predetermined value when the vehicle runs the standard running route;

a step of calculating an assist torque output instruction reference value for providing a steering angle change amount that makes the current steering angle closer to the required steering angle to the steering wheel and a torque output instruction reference value for providing a driving torque reduction amount that makes the current vehicle body speed closer to the appropriate vehicle body speed to a driving wheel of the vehicle;

a step of acquiring the standard yaw rate generated when the vehicle runs the standard running route;

a step of calculating a brake output instruction reference value for generating a yaw moment that makes a yaw rate acquired based on the current vehicle body speed and the current steering angle closer to the standard yaw rate on the vehicle;

a step of calculating a brake output instruction by multiplying the brake output instruction reference value by a brake moment amount weight which reduces as the assist torque output instruction reference value or the torque output instruction reference value increases; and

a step of outputting an assist torque output instruction based on the assist torque output instruction reference value, a torque output instruction based on torque output instruction reference value, and the brake output instruction to a steering assist apparatus capable of changing a steering angle, a driving apparatus configured to provide a driving torque to a driving wheel of the vehicle, and a brake apparatus capable of braking the vehicle, respectively.

10. A driving assist system comprising:

at least one of a camera, a GPS, and a map database configured to acquire curve information ahead of a vehicle; and

a controller configured to:

calculate a standard running route based on the curve information; and

acquire a current vehicle body speed and a current steering angle of a steering wheel as a current vehicle motion amount,

wherein a standard vehicle motion amount when the vehicle runs the standard running route is a standard yaw rate, a required steering angle, and an appropriate vehicle body speed,

the controller further configured to:

acquire the required steering angle for running the standard running route at the current vehicle body speed and the appropriate vehicle body speed at which a lateral acceleration matches or falls below a predetermined value when the vehicle runs the standard running route;

calculate an assist torque output instruction reference value for providing a steering angle change amount that makes the current steering angle closer to the required steering angle to the steering wheel and a torque output instruction reference value for providing a driving torque reduction amount that makes the current vehicle body speed closer to the appropriate vehicle body speed to a driving wheel of the vehicle;

acquire the standard yaw rate generated when the vehicle runs the standard running route;

calculate a brake output instruction reference value for generating a yaw moment that makes a yaw rate acquired based on the current vehicle body speed and the current steering angle closer to the standard yaw rate on the vehicle;

calculate a brake output instruction by multiplying the brake output instruction reference value by a brake moment amount weight which reduces as the assist torque output instruction reference value or the torque output instruction reference value increases; and

output an assist torque output instruction based on the assist torque output instruction reference value, a torque output instruction based on torque output instruction reference value, and the brake output instruction to a steering assist apparatus capable of changing a steering angle, a driving apparatus configured to provide a driving torque to a driving wheel of the vehicle, and a brake apparatus capable of braking the vehicle, respectively.