Vehicular adaptive cruise control apparatus and method with preceding vehicle following control function

• US 20020095254A1
• Filed: 01/17/2002
• Published: 07/18/2002
• Est. Priority Date: 01/18/2001
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Egawa, Kenichi, Kubota, Kenta
• Granted Patent: US 6,678,603 B2
• Time in Patent Office: Days
• US Class Current: 701/96
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration

Abstract

In adaptive cruise control apparatus and method for an automotive vehicle, a velocity of the vehicle is detected, an inter-vehicle distance between the vehicle and a preceding vehicle which is a controlled system of a following run control is detected, a driving force of the vehicle is controlled to maintain the inter-vehicle distance at a target inter-vehicle distance when the inter-vehicle distance between the vehicle and the other vehicle is detected and to maintain the velocity of the vehicle at a set vehicle speed when no other vehicle is detected on the same traffic lane in the forward direction of the vehicle, and an acceleration value at an initial stage of an acceleration is set in such a manner as to be larger than that at a later stage of acceleration when the other vehicle detection state is transferred from the detection state to a non-detection state.

Claims

1. An adaptive cruise control apparatus for an automotive vehicle, comprising:

a vehicular velocity detecting section that detects a velocity of the vehicle;

an inter-vehicle distance detecting section that detects an inter-vehicle distance between the vehicle and another vehicle which is traveling on the same traffic lane as the vehicle in a forward direction thereof;

a driving force controlling section that controls a driving force for the vehicle to maintain the inter-vehicle distance at a target inter-vehicle distance to achieve the following run control when the inter-vehicle distance detecting section detects the inter-vehicle distance between the vehicle and the other vehicle and to maintain the velocity of the vehicle at a set vehicle speed when the inter-vehicle distance detecting section detects no other vehicle on the same traffic lane in the forward direction thereof; and

an acceleration controlling section that sets an acceleration value at an initial stage of an acceleration in such a manner as to be larger than that at a later stage of the acceleration when the inter-vehicle distance detecting section transfers its other vehicle detection state from the detection state of the other vehicle to a non-detection state thereof.

2. An adaptive cruise control apparatus for an automotive vehicle as claimed in claim 1, wherein the acceleration controlling section sets a magnitude of the acceleration at the initial stage of acceleration to be large and, after the initial stage of the acceleration, the magnitude of the acceleration being gradually reduced along with an increase in the velocity of the vehicle.

3. An adaptive cruise control apparatus for an automotive vehicle as claimed in claim 1, wherein the acceleration controlling section sets the acceleration value at the initial stage of the acceleration to be smaller as the velocity of the vehicle at a time of a start of the acceleration becomes higher.

4. An adaptive cruise control apparatus for an automotive vehicle as claimed in claim 1, wherein the acceleration controlling section sets the acceleration at the initial stage of a stage of the acceleration to a value equal to or larger than a maximum value of the acceleration when the driving force controlling section controls the driving force for the vehicle to maintain the inter-vehicle distance at the target inter-vehicle distance to achieve the following run control.

5. An adaptive cruise control apparatus -for an automotive vehicle as claimed in claim 1, wherein the acceleration controlling section comprises an acceleration variation rate limiting section that limits an acceleration variation rate, the acceleration variation rate limiting section limiting the acceleration variation rate in such a manner that as the velocity of the vehicle becomes higher, the acceleration variation rate becomes smaller.

6. An adaptive cruise control apparatus for an automotive vehicle as claimed in claim 1, wherein the acceleration controlling section sets the acceleration at the initial stage of acceleration to become smaller as a deviation between the velocity of the vehicle at the initial stage of the acceleration and the set vehicle speed becomes smaller.

7. An adaptive cruise control apparatus for an automotive vehicle as claimed in claim 2, wherein the acceleration controlling section comprises an acceleration calculation map section , the acceleration calculation map representing a relationship between the set acceleration and the vehicular velocity of the vehicle, the acceleration calculation map comprising a plurality of characteristic lines, each characteristic line having a maximum acceleration value at its corresponding top end which corresponds to the acceleration at the initial stage of acceleration and having a plurality of gradients such that as the velocity of the vehicle is increased, a variation rate of the set acceleration is gradually reduced.

8. An adaptive cruise control apparatus for an automotive vehicle as claimed in claim 7, wherein the gradients of each characteristic line are such that as the velocity of the vehicle is increased, the variation rate of the set acceleration is reduced in a polygonal line manner.

9. An adaptive cruise control apparatus for an automotive vehicle as claimed in claim 7, wherein the maximum values of the respective characteristic lines are set to become smaller as the velocity of the vehicle at the initial stage of the acceleration becomes higher.

10. An adaptive cruise control apparatus for an automotive vehicle as claimed in claim 7, wherein the acceleration controlling section comprises an acceleration variation rate limiting section that limits the acceleration variation rate, the acceleration variation rate limiting section limiting the acceleration variation rate in such a manner that as the velocity of the vehicle becomes higher, the acceleration variation rate becomes smaller.

11. An adaptive cruise control apparatus for an automotive vehicle as claimed in claim 10, wherein the acceleration controlling section comprises an acceleration variation rate limiting section comprising:

an acceleration variation rate limit value calculating section that calculates an acceleration variation rate limit value Δ

α

on the basis of the set vehicle speed V_SET;

an acceleration limit value calculating section that calculates an acceleration limit value α

_L on the basis of the calculated acceleration limit value and a previous acceleration command value α

_R (i−

1) ; and

a determinator to determine whether a present set acceleration α

is equal to or larger than α

_L, and wherein the acceleration variation rate limiting section limits the set acceleration to α

_L when the determinator determines that α

≧

α

_L.

12. An adaptive cruise control apparatus for an automotive vehicle as claimed in claim 11, wherein the present acceleration command value α

_R is calculated as follows;

α

_R=K_G·

α

, wherein K_G denotes an acceleration gain derived on the basis of a vehicular velocity deviation Δ

V between the set vehicle speed V_SET and the velocity of the vehicle Vs at the start time of the acceleration.

13. An adaptive cruise control apparatus for an automotive vehicle as claimed in claim 12, wherein the acceleration gain K_G is set to “

0”

when the vehicular velocity deviation is zero and is set to “

1”

when the vehicular velocity deviation is increased and becomes equal to or larger than a preset value Δ

Vs.

14. An adaptive cruise control apparatus for an automotive vehicle, comprising:

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

inter-vehicle distance detecting section for detecting an inter-vehicle distance between the vehicle and another vehicle which is traveling on the same traffic lane as the vehicle in a forward direction thereof;

driving force controlling means for controlling a driving force for the vehicle to maintain the inter-vehicle distance at a target inter-vehicle distance to achieve the following run control when the inter-vehicle distance detecting means detects the inter-vehicle distance between the vehicle and the other vehicle and to maintain the velocity of the vehicle at a set vehicle speed when the inter-vehicle distance detecting means detects no other vehicle on the same traffic lane in the forward direction thereof; and

acceleration controlling means for setting an acceleration value at an initial stage of an acceleration in such a manner as to be larger than that at a later stage of the acceleration when the inter-vehicle distance detecting means transfers its other vehicle detection state from the detection state of the other vehicle to a non-detection state thereof.

15. An adaptive cruise control method for an automotive vehicle, comprising:

detecting a velocity of the vehicle;

detecting an inter-vehicle distance between the vehicle and another vehicle which is traveling on the same traffic lane as the vehicle in a forward direction thereof;

controlling a driving force for the vehicle to maintain the inter-vehicle distance at a target inter-vehicle distance to achieve the following run control when the inter-vehicle distance between the vehicle and the other vehicle is detected and to maintain the velocity of the vehicle at a set vehicle speed when no other vehicle is detected on the same traffic lane in the forward direction thereof; and

setting an acceleration value at an initial stage of an acceleration in such a manner as to be larger than that at a later stage of the acceleration when the other vehicle detection state is transferred from the detection state of the other vehicle to a non-detection state thereof.