ADAPTIVE CRUISE CONTROL SYSTEM FOR AUTOMOTIVE VEHICLES

• US 20020152015A1
• Filed: 03/27/2002
• Published: 10/17/2002
• Est. Priority Date: 04/16/2001
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Seto, Yoji
• Granted Patent: US 6,470,257 B1
• 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: B60K 31/042 where at least one electrical quantity is set by the vehicle operator
• CPC Class Codes: B60T 7/22 initiated by contact of vehicle, e.g. bumper, with an external object, e.g. another vehicle , or by means of contactless obstacle detectors mounted on the vehicle
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle

Abstract

An adaptive cruise control system for an automotive vehicle includes at least a host vehicle speed detector an engine torque control system and a brake control system for controlling at least one of a host vehicle'"'"'s speed, an inter-vehicle distance, and a relative velocity of the host vehicle to the preceding vehicle. When switching from an engine-torque-control-only operating mode suitable for a relatively small required host vehicle'"'"'s acceleration/deceleration to an engine-torque-control plus brake-control operating mode suitable for a relatively large required host vehicle'"'"'s acceleration/deceleration occurs, an initial value of a host vehicle'"'"'s speed command value is reset to a value being offset from the host vehicle'"'"'s speed by a predetermined value.

Claims

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

a vehicle speed detector that detects a host vehicle'"'"'s speed;

a man-machine interface that sets a desired host vehicle speed;

a plurality of braking-and-driving force control systems that control a braking-and-driving force of the host vehicle, so that the host vehicle'"'"'s speed is brought closer to the desired host vehicle speed; and

a controller configured to be electronically connected to the vehicle speed detector, the man-machine interface, and the plurality of braking-and-driving force control systems, for executing an adaptive cruise control;

the controller comprising;

(a) a braking-and-driving force control mode selector that selects at least one braking-and-driving force control system from the plurality of braking-and-driving force control systems, depending upon a host vehicle'"'"'s acceleration/deceleration required to bring the host vehicle'"'"'s speed closer to the desired host vehicle speed;

the braking-and-driving force control mode selector selecting a first braking-and-driving force control system when the required host vehicle'"'"'s acceleration/deceleration is less than a predetermined threshold value, and selecting a second braking-and-driving force control system when the required host vehicle'"'"'s acceleration/deceleration is greater than or equal to the predetermined threshold value, and

(b) a desired host vehicle speed compensator that resets the desired host vehicle speed set at a switching point between the first and second braking-and-driving force control systems at a value being offset from the host vehicle'"'"'s speed by a predetermined value when switching between the first and second braking-and-driving force control systems occurs.

3. The adaptive cruise control system as claimed in claim 1, further comprising:

a host vehicle'"'"'s acceleration/deceleration detection section that detects the host vehicle'"'"'s acceleration/deceleration; and

wherein;

the desired host vehicle speed compensator sets the predetermined value based on the host vehicle'"'"'s acceleration/deceleration detected just before the switching point between the first and second braking-and-driving force control systems.

5. The adaptive cruise control system as claimed in claim 1, wherein:

the first braking-and-driving force control system comprises an engine control system; and

the second braking-and-driving force control system comprises a brake control system.

6. The adaptive cruise control system as claimed in claim 1, wherein:

the first braking-and-driving force control system comprises an engine control system; and

the second braking-and-driving force control system comprises the engine control system and a brake control system.

2. An adaptive cruise control system for an automotive vehicle, comprising:

an inter-vehicle distance detector that detects an inter-vehicle distance between a host vehicle and a preceding vehicle;

a vehicle speed detector that detects a host vehicle'"'"'s speed;

a plurality of braking-and-driving force control systems that control a braking-and-driving force of the host vehicle, so that the host vehicle'"'"'s speed is brought closer to a desired host vehicle speed; and

a controller configured to be electronically connected to the inter-vehicle distance detector, the vehicle speed detector, and the plurality of braking-and-driving force control systems, for executing an adaptive cruise control;

the controller comprising;

(a) a desired inter-vehicle distance setting section that sets a desired inter-vehicle distance from the host vehicle to the preceding vehicle;

(b) a desired host vehicle speed computation section that computes the desired host vehicle speed needed to bring the inter-vehicle distance closer to the desired inter-vehicle distance;

(c) a braking-and-driving force control mode selector that selects at least one braking-and-driving force control system from the plurality of braking-and-driving force control systems, depending upon a host vehicle'"'"'s acceleration/deceleration required to bring the host vehicle'"'"'s speed closer to the desired host vehicle speed;

the braking-and-driving force control mode selector selecting a first braking-and-driving force control system when the required host vehicle'"'"'s acceleration/deceleration is less than a predetermined threshold value, and selecting a second braking-and-driving force control system when the required host vehicle'"'"'s acceleration/deceleration is greater than or equal to the predetermined threshold value, and

(d) a desired host vehicle speed compensator that resets the desired host vehicle speed computed at a switching point between the first and second braking-and-driving force control systems at a value being offset from the host vehicle'"'"'s speed by a predetermined value when switching between the first and second braking-and-driving force control systems occurs.

4. The adaptive cruise control system as claimed in claim 2, further comprising:

a host vehicle'"'"'s acceleration/deceleration detection section that detects the host vehicle'"'"'s acceleration/deceleration; and

a relative velocity detection section that detects a relative velocity of the host vehicle to the preceding vehicle, and wherein;

the desired host vehicle speed compensator sets the predetermined value based on the host vehicle'"'"'s acceleration/deceleration, the relative velocity, and the inter-vehicle distance, each detected just before the switching point between the first and second braking-and-driving force control systems.

7. The adaptive cruise control system as claimed in claim 2, wherein:

the desired inter-vehicle distance setting section calculates the desired inter-vehicle distance based on the host vehicle'"'"'s speed and a predetermined inter-vehicle time substantially corresponding to an elapsed time before the host vehicle is brought into contact with the preceding vehicle.

8. The adaptive cruise control system as claimed in claim 2, wherein:

the inter-vehicle distance detector comprises a frontal object detector section that captures the preceding vehicle, and a frontal object detector signal processing circuit that receives an input signal from the frontal object detector section and processes the input signal to determine whether the preceding vehicle is present or absent; and

the switching point corresponds to a switching point between a state that the preceding vehicle is absent and a state that the preceding vehicle is present.

9. A method for automatically controlling at least one of a host vehicle'"'"'s speed, an inter-vehicle distance between the host vehicle and a preceding vehicle, and a relative velocity of the host vehicle to the preceding vehicle, the method comprising:

detecting the host vehicle'"'"'s speed;

detecting the inter-vehicle distance;

detecting the relative velocity;

computing a first desired host vehicle speed based on a driver-selected vehicle speed;

computing a second desired host vehicle speed based on the inter-vehicle distance and the relative velocity;

setting a desired host vehicle speed at the first desired host vehicle speed when the preceding vehicle is absent;

setting the desired host vehicle speed at the second desired host vehicle speed when the preceding vehicle is present;

selecting a first braking-and-driving force control mode suitable for a first demand for acceleration/deceleration when a required host vehicle'"'"'s acceleration/deceleration is less than a predetermined threshold value;

selecting a second braking-and-driving force control mode suitable for a second demand greater than the first demand for acceleration/deceleration when the required host vehicle'"'"'s acceleration/deceleration is greater than or equal to the predetermined threshold value; and

resetting the desired host vehicle speed computed at a switching point between the first and second braking-and-driving force control modes at a value being offset from the host vehicle'"'"'s speed by a predetermined value when switching between the first and second braking-and-driving force control modes occurs.

10. The method as claimed in claim 9, wherein:

the first braking-and-driving force control mode comprises an engine-torque-control-only operating mode at which a braking-and-driving force of the host vehicle is controlled by way of only an engine control; and

the second braking-and-driving force control mode comprises an engine-torque-control plus brake-control operating mode at which the braking-and-driving force of the host vehicle is controlled by way of a brake control as well as the engine control.

11. An adaptive cruise control system for an automotive vehicle, comprising:

a vehicle speed detection means for detecting a host vehicle'"'"'s speed;

a man-machine interface for setting a desired host vehicle speed;

a plurality of braking-and-driving force control systems that control a braking-and-driving force of the host vehicle, so that the host vehicle'"'"'s speed is brought closer to the desired host vehicle speed; and

a controller configured to be electronically connected to the vehicle speed detection means, the man-machine interface, and the plurality of braking-and-driving force control systems, for executing an adaptive cruise control;

the controller comprising;

(a) a braking-and-driving force control mode selecting means for selecting at least one braking-and-driving force control system from the plurality of braking-and-driving force control systems, depending upon a host vehicle'"'"'s acceleration/deceleration required to bring the host vehicle'"'"'s speed closer to the desired host vehicle speed;

the braking-and-driving force control mode selecting means selecting a first braking-and-driving force control system when the required host vehicle'"'"'s acceleration/deceleration is less than a predetermined threshold value, and selecting a second braking-and-driving force control system when the required host vehicle'"'"'s acceleration/deceleration is greater than or equal to the predetermined threshold value, and

(b) a desired host vehicle speed compensating means for resetting the desired host vehicle speed set at a switching point between the first and second braking-and-driving force control systems at a value being offset from the host vehicle'"'"'s speed by a predetermined value when switching between the first and second braking-and-driving force control systems occurs.

12. An adaptive cruise control system for an automotive vehicle, comprising:

an inter-vehicle distance detection means for detecting an inter-vehicle distance between a host vehicle and a preceding vehicle;

a vehicle speed detection means for detecting a host vehicle'"'"'s speed;

a plurality of braking-and-driving force control systems that control a braking-and-driving force of the host vehicle, so that the host vehicle'"'"'s speed is brought closer to a desired host vehicle speed; and

a controller configured to be electronically connected to the inter-vehicle distance detector, the vehicle speed detector, and the plurality of braking-and-driving force control systems, for executing an adaptive cruise control;

the controller comprising;

(a) a desired inter-vehicle distance setting means for setting a desired inter-vehicle distance from the host vehicle to the preceding vehicle;

(b) a desired host vehicle speed computation means for computing the desired host vehicle speed needed to bring the inter-vehicle distance closer to the desired inter-vehicle distance;

(c) a braking-and-driving force control mode selecting means for selecting at least one braking-and-driving force control system from the plurality of braking-and-driving force control systems, depending upon a host vehicle'"'"'s acceleration/deceleration required to bring the host vehicle'"'"'s speed closer to the desired host vehicle speed;

the braking-and-driving force control mode selecting means selecting a first braking-and-driving force control system when the required host vehicle'"'"'s acceleration/deceleration is less than a predetermined threshold value, and selecting a second braking-and-driving force control system when the required host vehicle'"'"'s acceleration/deceleration is greater than or equal to the predetermined threshold value, and

(d) a desired host vehicle speed compensating means for resetting the desired host vehicle speed computed at a switching point between the first and second braking-and-driving force control systems at a value being offset from the host vehicle'"'"'s speed by a predetermined value when switching between the first and second braking-and-driving force control systems occurs.