Vehicular velocity controlling apparatus and method to follow up a preceding vehicle running ahead of vehicle

• US 6,415,217 B1
• Filed: 06/12/2000
• Issued: 07/02/2002
• Est. Priority Date: 06/15/1999
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Adachi, Kazutaka, Hashizume, Takenori, Higashimata, Akira
• Primary Examiner(s): Louis-Jacques, Jacques H.
• Assistant Examiner(s): BROADHEAD, BRIAN J
• Application Number:
  US09/592,567
• Time in Patent Office: 750 Days
• Field of Search: 701/93, 701/96, 180/169, 180/170, 180/171, 340/903, 340/435, 340/436, 382/69, 382/70
• US Class Current: 701/96
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60W 2050/0022 Gains, weighting coefficients or weighting functions
• CPC Class Codes: B60W 2050/0031 Mathematical model of the vehicle
• CPC Class Codes: B60W 2754/30 Longitudinal distance
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle
• CPC Class Codes: G05D 1/0289 with means for avoiding collisions between vehicles vehicle fittings for automatically controlling speed including means for detecting potential obstacles B60K31/0008; avoiding obstacles by action on the steering system B62D; radar, sonar, lidar systems designed for anti-collision purposes G01S13/93, G01S15/93, G01S17/93

Abstract

In vehicular velocity controlling apparatus and method for an automotive vehicle, an inter-vehicle distance from the vehicle to a preceding vehicle which is running ahead of the vehicle is detected, a vehicular velocity of the vehicle is detected; a relative velocity of the vehicle to the preceding vehicle is detected, a target inter-vehicle distance is calculated on the basis of detected values of the inter-vehicle distance and of the vehicular velocity, a control response characteristic of an inter-vehicle distance system to the target inter-vehicle distance is determined, an inter-vehicle distance command value based on the target inter-vehicle distance is calculated in accordance with the determined control response characteristic, a target vehicular velocity is calculated on the basis of the inter-vehicle distance command value, and the vehicular velocity is controlled to make the detected value of the vehicular velocity substantially equal to the target vehicular velocity, the control response characteristic being determined in accordance with a correlation in magnitude between the target inter-vehicle distance, the inter-vehicle distance command value, and the detected value of the inter-vehicle distance.

Claims

1. A vehicular velocity controlling apparatus for an automotive vehicle, comprising:

an inter-vehicle distance detector to detect an inter-vehicle distance from the vehicle to a preceding vehicle which is running ahead of the vehicle;

a vehicular velocity detector to detect a vehicular velocity of the vehicle;

a relative velocity detector to detect a relative velocity of the vehicle to the preceding vehicle;

a target inter-vehicle distance calculating section that calculates a target inter-vehicle distance on the basis of detected values of the inter-vehicle distance and of the vehicular velocity;

a control response characteristic determining section that determines a control response characteristic of an inter-vehicle distance system to the target inter-vehicle distance;

an inter-vehicle distance command value calculating section that calculates an inter-vehicle distance command value based on the target inter-vehicle distance in accordance with the determined control response characteristic;

a target vehicular velocity calculating section that calculates a target vehicular velocity on the basis of the inter-vehicle distance command value; and

a vehicular velocity controlling section that controls the vehicular velocity to make the detected value of the vehicular velocity substantially equal to the target vehicular velocity, the control response characteristic determining section determining the control response characteristic in accordance with a correlation in magnitude based on the target inter-vehicle distance, the inter-vehicle distance command value, and the detected value of the inter-vehicle distance.

2. A vehicular velocity controlling apparatus for an automotive vehicle as claimed in claim 1, wherein the inter-vehicle distance command value calculating section calculates the inter-vehicle distance command value on the basis of the target inter-vehicle distance using a reference model prescribed by a damping factor and a specific angular frequency and wherein the control response characteristic determining section includes:

a high response required state determining section that determines whether the vehicle is running to follow up the preceding vehicle under a high response required state from the correlation in magnitude between the target inter-vehicle distance, the inter-vehicle distance command value; and

the detected value of the inter-vehicle distance; and

a selecting section that selects the specific angular frequency from a specific angular frequency memory table representing a relationship between a deviation of the target inter-vehicle distance from the detected value of the inter-vehicle distance, the relative velocity, and the specific angular frequency when the high response characteristic determining section determines that the vehicle is running to follow up the preceding vehicle under no high response required state and that selects a high response purpose specific angular frequency when the high response required state determining section determines that the vehicle is running to follow up the preceding vehicle under the high response required state.

3. A vehicular velocity controlling apparatus for an automotive vehicle as claimed in claim 2, wherein the high response state required section determines that the vehicle is running to follow up the preceding vehicle under the high response required state when the inter-vehicle distance command value is larger than the detected value of the inter-vehicle distance and is larger than the target inter-vehicle distance.

4. A vehicular velocity controlling apparatus for an automotive vehicle as claimed in claim 2, wherein the high response state required section determines that the vehicle is running to follow up the preceding vehicle under the high response required state when the inter-vehicle distance command value is smaller than the target inter-vehicle distance and the detected value of the inter-vehicle distance is smaller than the inter-vehicle distance command value.

5. A vehicular velocity controlling apparatus for an automotive vehicle as claimed in claim 2, wherein the selecting section is enabled to select the high response purpose specific angular frequency only when the vehicle is approaching to the preceding vehicle.

6. A vehicular velocity controlling apparatus for an automotive vehicle as claimed in claim 3, wherein the magnitude of the high response purpose specific angular frequency ω

_nH is larger than that of each specific angular frequency data ω

n stored in the specific angular frequency memory table.

7. A vehicular velocity controlling apparatus for an automotive vehicle as claimed in claim 3, wherein the inter-vehicle distance command value calculating section includes a damping factor calculating section that calculates the damping factor e on the basis of the deviation of the target inter-vehicle distance from the detected value of the inter-vehicle distance (Δ

L=L−

L*) and the relative velocity Δ

V from a damping factor memory table representing the relationship between the deviation of the target inter-vehicle distance and the detected value of the inter-vehicle distance, and the relative velocity.

8. A vehicular velocity controlling apparatus for an automotive vehicle as claimed in claim 7, wherein the vehicular velocity controlling section includes a vehicular velocity servo system that calculates a driving force command value F_OR and a disturbance estimated value dv{circumflex over ( )}to make the detected value of the vehicular velocity Vs substantially equal to the target vehicular velocity V* and calculates a target vehicular driving force F* which is a deviation between the driving force command value F_OR and the disturbance estimated value dv{circumflex over ( )}to make the detected value of the vehicular velocity Vs substantially equal to the target vehicular velocity V* and calculates a target vehicular driving force F* which is a deviation between the driving force command value F_OR and the disturbance estimated value dv{circumflex over ( )}and wherein the selecting section includes:

a first comparator to compare the target vehicular driving force F* with a braking force threshold value TH_B to determine if F*≦

TH_B;

a second comparator to compare the inter-vehicle distance command value with the target inter-vehicle distance L* to determine if L_T>

L* when the first comparator determines that F*≦

TH_B;

a third comparator to compare the inter-vehicle distance command value L_T with the detected value of the inter-vehicle distance L to determine if L_T>

L when the second comparator determines that L_T>

I*;

a fourth comparator to compare the inter-vehicle distance command value L_T with the detected value of the inter-vehicle distance L to determine if L_T>

L when the second comparator determines that L_T≦

L*; and

a setter to set the high response purpose specific angular frequency ω

n (ω

n←

unH) when the third comparator determines that L_T>

L or when the fourth comparator determines that L_T>

L.

9. A vehicular velocity controlling apparatus for an automotive vehicle as claimed in claim 8, wherein the inter-vehicle distance command value calculating section calculates the target inter-vehicle distance command value L_T on the basis of the high response purpose specific angular frequency ω

nH set by the setter.

10. A vehicular velocity controlling apparatus for an automotive vehicle as claimed in claim 9, wherein the inter-vehicle distance command value calculating section calculates the target inter-vehicle distance command value L_T on the basis of the specific angular frequency when the first comparator determines that F*>

TH_B when the third comparator determines that L_T≦

L.

11. A vehicular velocity controlling apparatus for an automotive vehicle as claimed in claim 9, wherein the selecting section further includes a fifth comparator to compare the relative velocity Δ

V with zero to determine if the vehicle is approaching to the preceding vehicle at a negative relative velocity and the setter is enabled to set the high response purpose specific angular frequency as the specific angular frequency (ω

n=ω

nH) when the fifth comparator determines that the vehicle is approaching to the preceding vehicle.

12. A vehicular velocity controlling apparatus for an automotive vehicle as claimed in claim 11, wherein the high response purpose angular frequency ù

nH is approximately 0.5 radian/sec.

13. A vehicular velocity controlling apparatus for an automotive vehicle, comprising:

inter-vehicle distance detecting means for detecting an inter-vehicle distance from the vehicle to a preceding vehicle which is running ahead of the vehicle;

vehicular velocity detecting means for detecting a vehicular velocity of the vehicle;

relative velocity detecting means for detecting a relative velocity of the vehicle to the preceding vehicle;

target inter-vehicle distance calculating means for calculating a target inter-vehicle distance on the basis of detected values of the inter-vehicle distance and of the vehicular velocity;

control response characteristic determining means for determining a response characteristic of an inter-vehicle distance system to the target inter-vehicle distance;

inter-vehicle distance command value calculating means for calculating an inter-vehicle distance command value based on the target inter-vehicle distance in accordance with the determined control response characteristic;

target vehicular velocity calculating means for calculating a target vehicular velocity on the basis of the inter-vehicle distance command value; and

vehicular velocity controlling means for controlling the vehicular velocity to make the detected value of the vehicular velocity substantially equal to the target vehicular velocity, the control response characteristic determining means determining the control response characteristic in accordance with a correlation in magnitude between the target inter-vehicle distance, the inter-vehicle distance command value, and the detected value of the inter-vehicle distance.

14. A vehicular velocity controlling method for an automotive vehicle, comprising:

detecting an inter-vehicle distance from the vehicle to a preceding vehicle which is running ahead of the vehicle;

detecting a vehicular velocity of the vehicle;

detecting a relative velocity of the vehicle to the preceding vehicle;

calculating a target inter-vehicle distance on the basis of detected values of the inter-vehicle distance and of the vehicular velocity;

determining a control response characteristic of an inter-vehicle distance system to the target inter-vehicle distance;

calculating an inter-vehicle distance command value based on the target inter-vehicle distance in accordance with the determined control response characteristic;

calculating a target vehicular velocity on the basis of the inter-vehicle distance command value; and

controlling the vehicular velocity to make the detected value of the vehicular velocity substantially equal to the target vehicular velocity and wherein the control response characteristic determining step determines the control response characteristic in accordance with a correlation in magnitude between the target inter-vehicle distance, the inter-vehicle distance command value, and the detected value of the inter-vehicle distance.