Method and Apparatus for Performing Driving Assistance

• US 20150094927A1
• Filed: 01/29/2014
• Published: 04/02/2015
• Est. Priority Date: 09/30/2013
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: TAKAHASHI, Junya, ALTMANNSHOFER, Heiko, YAMAKADO, Makoto, KOJIMA, Takao
• Granted Patent: US 9,043,116 B2
• Time in Patent Office: Days
• US Class Current: 701/93
• CPC Class Codes: B60W 2050/0025 Transfer function weighting factor
• CPC Class Codes: B60W 2050/0027 Minimum/maximum value selectors
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/125 Lateral acceleration
• CPC Class Codes: B60W 2552/30 Road curve radius
• CPC Class Codes: B60W 2554/801 Lateral distance
• CPC Class Codes: B60W 2554/804 Relative longitudinal speed
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration
• CPC Class Codes: B60W 2720/125 Lateral acceleration
• CPC Class Codes: B60W 30/025 related to comfort of drivers or passengers
• CPC Class Codes: B60W 30/045 Improving turning performance
• CPC Class Codes: B60W 30/143 Speed control B60W30/16 takes precedence
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle
• CPC Class Codes: B60W 30/18145 Cornering
• CPC Class Codes: G05D 13/02 Details

Abstract

The present invention relates to methods and apparatuses for performing driving assistance for a controlled vehicle, involving determining a first longitudinal acceleration target value on the basis of a lateral acceleration of the controlled vehicle, determining a second longitudinal acceleration target value on the basis of a target speed of the controlled vehicle, determining a third longitudinal acceleration target value based on a minimum value of the first longitudinal acceleration target value and the second longitudinal acceleration target value, and controlling a longitudinal acceleration of the controlled vehicle on the basis of the determined third longitudinal acceleration target value.

Claims

1. Method for performing driving assistance for a controlled vehicle moving in a longitudinal direction on a road, comprising:

determining a first longitudinal acceleration target value (G<sub>XT—

PGVC</sub>;

G<sub>XT—

PGVC—

adjust</sub>) on the basis of a lateral acceleration (G_Y;

G<sub>Y—

PV</sub>) of the controlled vehicle,

determining a second longitudinal acceleration target value (G<sub>XT—

ACC</sub>;

G<sub>XT—

ACC—

adjust</sub>) on the basis of a target speed of the controlled vehicle,

determining a third longitudinal acceleration target value based on a minimum value of the first longitudinal acceleration target value (G<sub>XT—

PGVC</sub>;

G<sub>XT—

PGVC—

adjust</sub>) and the second longitudinal acceleration target value (G<sub>XT—

ACC</sub>;

G<sub>XT—

ACC—

adjust</sub>), and

controlling a longitudinal acceleration (G_X) of the controlled vehicle on the basis of the determined third longitudinal acceleration target value (G_XT).

2. Method according to claim 1, wherein

the second longitudinal acceleration target value (G_XT—

_ACC;

G<sub>XT—

ACC—

adjust</sub>) is determined according to cruise control on the basis of the target speed of the controlled vehicle, or the second longitudinal acceleration target value (G<sub>XT—

ACC</sub>;

G<sub>XT—

ACC—

adjust</sub>) is determined according to adaptive cruise control on the basis of the target speed of the controlled vehicle and on the basis of a target distance from the controlled vehicle to a proceeding vehicle.

3. Method according to claim 1, wherein

determining the first longitudinal acceleration target value (G_XT—

<sub>PGVC—

adjust</sub>) comprises determining a fourth longitudinal acceleration target value (G<sub>XT—

PGVC</sub>) on the basis of a lateral acceleration (G_Y;

G<sub>Y—

PV</sub>) of the controlled vehicle and adjusting the fourth longitudinal acceleration target value (G<sub>XT—

PGVC</sub>) on the basis of at least one of;

a difference (Δ

V_tgt) between an actual speed of the controlled vehicle and the target speed of the controlled vehicle,

a difference (Δ

D) between an actual distance from the controlled vehicle to a proceeding vehicle and a target distance from the controlled vehicle to the proceeding vehicle,

a difference (Δ

V_vpv) between a speed of the controlled vehicle and a speed of the proceeding vehicle, and

an estimated lateral acceleration (G<sub>y—

est</sub>) of the controlled vehicle at a preview point of the road ahead of the controlled vehicle, the estimated lateral acceleration (G<sub>y—

est</sub>) being calculated on the basis of an estimation of curvature of the road at the preview point and the current speed of the controlled vehicle.

4. Method according to claim 3, wherein

adjusting the fourth longitudinal acceleration target value (G_XT—

_PGVC) is performed based on a first weighting factor (1−

kW) being determined from a weighting function depending on at least one of;

the difference (Δ

V_tgt) between the actual speed of the controlled vehicle and the target speed of the controlled vehicle,

the difference (Δ

D) between the actual distance from the controlled vehicle to the proceeding vehicle and the target distance from the controlled vehicle to the proceeding vehicle,

the difference (Δ

V_vpv) between the speed of the controlled vehicle and the speed of the proceeding vehicle, and

the estimated lateral acceleration (G<sub>y—

est</sub>) of the controlled vehicle at the preview point of the road ahead of the controlled vehicle.

5. Method according to claim 3, wherein

adjusting the fourth longitudinal acceleration target value (G_XT—

_PGVC) is performed based on a first weighting factor (1−

kW) being determined from at least one of;

a first weighting function depending on the difference (Δ

V_tgt) between the actual speed of the controlled vehicle and the target speed of the controlled vehicle,

a second weighting function depending on the difference (Δ

D) between the actual distance from the controlled vehicle to the proceeding vehicle and the target distance from the controlled vehicle to the proceeding vehicle,

a third weighting function depending on the difference (Δ

V_vpv) between the speed of the controlled vehicle and the speed of the proceeding vehicle, and

a fourth weighting function depending on the estimated lateral acceleration (G<sub>y—

est</sub>) of the controlled vehicle at the preview point of the road ahead of the controlled vehicle.

6. Method according to claim 1, wherein determining the second longitudinal acceleration target value (G_XT—

<sub>ACC—

adjust</sub>) comprises determining a fifth longitudinal acceleration target value (G<sub>XT—

ACC</sub>) on the basis of the target speed of the controlled vehicle and adjusting the fifth longitudinal acceleration target value (G<sub>XT—

ACC</sub>) on the basis of at least one of;

a difference (Δ

V_tgt) between an actual speed of the controlled vehicle and the target speed of the controlled vehicle,

a difference (Δ

D) between an actual distance from the controlled vehicle to a proceeding vehicle and a target distance from the controlled vehicle to the proceeding vehicle,

a difference (Δ

V_vpv) between a speed of the controlled vehicle and a speed of the proceeding vehicle, and

an estimated lateral acceleration (G<sub>y—

est</sub>) of the controlled vehicle at a preview point of the road ahead of the controlled vehicle, the estimated lateral acceleration (G<sub>y—

est</sub>) being calculated on the basis of an estimation of curvature of the road at the preview point and the current speed of the controlled vehicle.

7. Method according to claim 6, wherein

adjusting the fifth longitudinal acceleration target value (G_XT—

_ACC) is performed based on a second weighting factor (kW) being determined from a weighting function depending on at least one of;

the difference (Δ

V_tgt) between the actual speed of the controlled vehicle and the target speed of the controlled vehicle,

the difference (Δ

D) between the actual distance from the controlled vehicle to the proceeding vehicle and the target distance from the controlled vehicle to the proceeding vehicle,

the difference (Δ

V_vpv) between the speed of the controlled vehicle and the speed of the proceeding vehicle, and

the estimated lateral acceleration (G<sub>y—

est</sub>) of the controlled vehicle at the preview point of the road ahead of the controlled vehicle.

8. Method according to claim 6, wherein

adjusting the fifth longitudinal acceleration target value (G_XT—

_ACC) is performed based on a second weighting factor (kW) being determined from at least one of;

a first weighting function depending on the difference (Δ

V_tgt) between the actual speed of the controlled vehicle and the target speed of the controlled vehicle,

a second weighting function depending on the difference (Δ

D) between the actual distance from the controlled vehicle to the proceeding vehicle and the target distance from the controlled vehicle to the proceeding vehicle,

a third weighting function depending on the difference (Δ

V_vpv) between the speed of the controlled vehicle and the speed of the proceeding vehicle, and

a fourth weighting function depending on the estimated lateral acceleration (G<sub>y—

est</sub>) of the controlled vehicle at the preview point of the road ahead of the controlled vehicle.

9. Method according to claim 4, wherein the first and second weighting factors (1−

kW, kW) are determined from the same weighting functions such that the sum of the first and second weighting factors (1−

kW, kW) amounts to 1.

10. Method according to claim 9, wherein

adjusting the fourth longitudinal acceleration target value (G_XT—

_PGVC) is performed such that;

the first longitudinal acceleration target value (G<sub>XT—

PGVC—

adjust</sub>) is determined as the fourth longitudinal acceleration target value (G<sub>XT—

PGVC</sub>), if the fourth longitudinal acceleration target value (G<sub>XT—

PGVC</sub>) is smaller than zero, and

the first longitudinal acceleration target value (G<sub>XT—

PGVC—

adjust</sub>) is determined by subtracting, from the fourth longitudinal acceleration target value (G<sub>XT—

PGVC</sub>), the product of the first weighting factor (1−

kW) and the difference between the fourth longitudinal acceleration target value (G<sub>XT—

PGVC</sub>) and the fifth longitudinal acceleration target value (G<sub>XT—

ACC</sub>), if the fourth longitudinal acceleration target value (G<sub>XT—

PGVC</sub>) is equal to or larger than zero.

11. Method according to claim 9, wherein

adjusting the fifth longitudinal acceleration target value (G_XT—

_ACC) is performed such that;

the second longitudinal acceleration target value (G<sub>XT—

ACC—

adjust</sub>) is determined as the fifth longitudinal acceleration target value (G<sub>XT—

ACC</sub>), if the fifth longitudinal acceleration target value (G<sub>XT—

ACC</sub>) is larger than the fourth longitudinal acceleration target value (G<sub>XT—

PGVC</sub>), and

the second longitudinal acceleration target value (G<sub>XT—

ACC—

adjust</sub>) is determined by adding, to the fifth longitudinal acceleration target value (G<sub>XT—

ACC</sub>), the product of the second weighting factor (kW) and the difference between the fourth longitudinal acceleration target value (G<sub>XT—

PGVC</sub>) and the fifth longitudinal acceleration target value (G<sub>XT—

ACC</sub>), if the fifth longitudinal acceleration target value (G<sub>XT—

ACC</sub>) is equal to or smaller than the fourth longitudinal acceleration target value (G<sub>XT—

PGVC</sub>).

12. Method according to claim 1, wherein determining the first longitudinal acceleration target value (G_XT—

_PGVC;

G<sub>XT—

PGVC—

adjust</sub>) comprises determining a sixth longitudinal acceleration target value (G<sub>XT—

GVC</sub>) being calculated on the basis of a determined lateral acceleration (G_Y) and a corresponding lateral jerk (Ġ

_Y) of the vehicle during cornering.

13. Method according to claim 1, wherein determining the first longitudinal acceleration target value (G_XT—

_PGVC;

G<sub>XT—

PGVC—

adjust</sub>) comprises determining a seventh longitudinal acceleration target value (G<sub>XT—

PV</sub>) being calculated on the basis of an predicted lateral acceleration (G<sub>Y—

PV</sub>) of the vehicle at a preview point, which is located ahead of the controlled vehicle at a predetermined preview distance (L_pv) or at a preview distance (L_pv) which is calculated on the basis of a predetermined preview time (t_pv) and the current speed of the vehicle, the estimated lateral acceleration (G<sub>y—

est</sub>) at a preview point being calculated on the basis of an estimation of curvature of the road at the preview point and the current speed of the controlled vehicle.

14. Method according to claim 12, wherein

the first longitudinal acceleration target value (G_XT—

_PGVC) is determined based on the sixth longitudinal acceleration target value (G<sub>XT—

GVC</sub>) and the seventh longitudinal acceleration target value (G<sub>XT—

PV</sub>).

15. Apparatus for performing driving assistance for a controlled vehicle moving in a longitudinal direction on a road according to claim 1, comprising:

first longitudinal acceleration target value determining means (120;

400) for determining a first longitudinal acceleration target value (G<sub>XT—

PGVC</sub>;

G<sub>XT—

PGVC—

adjust</sub>) on the basis of a lateral acceleration (G_Y;

G<sub>Y—

PV</sub>) of the controlled vehicle,

second longitudinal acceleration target value determining means (110;

300) for determining a second longitudinal acceleration target value (G<sub>XT—

ACC</sub>;

G<sub>XT—

ACC—

adjust</sub>) on the basis of a target speed of the controlled vehicle,

third longitudinal acceleration target value determining means (130;

100) for determining a third longitudinal acceleration target value based on a minimum value of the first longitudinal acceleration target value (G<sub>XT—

PGVC</sub>;

G<sub>XT—

PGVC—

adjust</sub>) and the second longitudinal acceleration target value (G<sub>XT—

ACC</sub>;

G<sub>XT—

ACC—

adjust</sub>), and

longitudinal acceleration control means (100) for controlling a longitudinal acceleration (G_X) of the controlled vehicle on the basis of the determined third longitudinal acceleration target value (G_XT).

16. Computer program product comprising computer program means for causing a vehicle control apparatus to execute the steps of claim 1.