Method and device for setting the vehicle longitudinal velocity to a deired speed

• US 20020138190A1
• Filed: 04/11/2002
• Published: 09/26/2002
• Est. Priority Date: 04/17/2000
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Winner, Hermann, Irion, Albrecht, Hellmann, Manfred, Lauxmann, Ralph
• Granted Patent: US 6,591,181 B2
• Time in Patent Office: Days
• US Class Current: 701/78
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60K 31/04 and means for comparing one electrical quantity, e.g. voltage, pulse, waveform, flux, or the like, with another quantity of a like kind, which comparison means is involved in the development of an electrical signal which is fed into the controlling means
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle

Abstract

A method and a device for setting the longitudinal speed of a vehicle to a setpoint speed is described, in particular on the basis of a regulation, having controllable brake units. In operation of a cruise control system, it may occur that the cruise control is activated again when the instantaneous driving speed is significantly higher than the stored setpoint speed. In this situation, there may be unwanted braking responses by the regulator which could endanger the driver and the following road users. In such a situation, the method according to the present invention prevents a braking measure from being implemented and ensures that the vehicle will coast, being braked only by the road resistance and the drag on the engine, until reaching the set speed. Through this method, the driving response of the cruise control system approximates that of a human driver, so the responses of the automatic cruise control seem more intelligible for the driver.

Claims

1. A method of setting the longitudinal speed of a vehicle to a setpoint speed of a vehicle, in particular on the basis of a regulation, having controllable brake units,

wherein

in the case of at least one first operating mode (normal deceleration case) in which the longitudinal speed of the vehicle exceeds the setpoint speed by a preselectable extent, the setpoint speed is set by controlling the brake units, and

in the case of at least one second operating mode (resume-delay, suspend-delay) in which the longitudinal speed of the vehicle exceeds the setpoint speed by the preselectable extent, the setpoint speed is set without controlling the brake units.

2. The method according to claim 1, wherein the second operating mode is initiated when the vehicle longitudinal speed exceeds the setpoint speed by the preselectable extent, and at the same time the operating element for resumption of the speed setting (resume) is operated (resume-delay operating mode).

3. The method according to claim 1, wherein the second operating mode is initiated when the vehicle longitudinal speed exceeds the setpoint speed at least by the preselectable extent (suspend-delay operating mode) due to actuation of a means operable by the driver of the vehicle for selecting the speed, in particular a gas pedal, in the sense of a speed increase.

4. The method according to claim 1, wherein the second operating mode is terminated when

the longitudinal speed of the vehicle exceeds the setpoint speed by less than the preselectable extent, or

a time limit on the second operating mode is exceeded, or

the driver reduces the setpoint speed by actuating at least one operating element, or

the driver deactivates the system for setting the speed by actuating at least one operating element for deactivation of the system or by actuating a braking device, or

a distance and speed sensor provided on the vehicle, preferably an ACC sensor, detects an obstacle in the same lane as the vehicle, its distance being less than a preselectable distance.

5. The method according to claim 1, wherein in the case of the second operating mode and simultaneous detection that the vehicle is driving downhill, a braking measure is initiated, its delay moment depending on the gradient of the downhill segment of road, in particular when the negative road resistance is greater than the drag on the vehicle engine.

6. The method according to claim 1, wherein the occurrence of the second operating mode is flagged by setting or deleting identifiers in a respective device, different identifiers being provided for the “

resume-delay”

case or the “

suspend-delay”

case, so that a distinction can be made between these two cases.

7. A device for regulating the longitudinal speed of a vehicle and the distance of a vehicle from a second vehicle driving in front of it, in which case this device may have one or more of the following features:

means for controlling braking devices,

a predetermined first identifier which indicates the presence of at least one preselectable first operating mode (normal deceleration case) in which the longitudinal speed of the vehicle exceeds the setpoint speed by a preselectable extent, and the setpoint speed is set by controlling the brake units,

a predetermined second identifier which indicates the presence of at least one preselectable second operating mode (resume-delay, suspend-delay) in which the longitudinal speed of the vehicle exceeds the setpoint speed by the preselectable extent, and the setpoint speed is set without controlling the brake units,

means for detecting and processing an inclination of the road surface in the longitudinal direction of the vehicle,

driver operable means for activation, deactivation, resumption and adjustment of the setpoint speed of the system for setting the speed.

8. The device according to claim 7, wherein the occurrence of the second operating mode is detected and it is noted in the device when the longitudinal speed of the vehicle exceeds the setpoint speed by the preselectable extent and at the same time the operating element for reactivation of the speed setting (resume) is actuated (resume-delay operating mode) or when the longitudinal speed of the vehicle exceeds the setpoint speed at least by the preselectable extent (suspend-delay operating mode) due to actuation of a means operable by the driver of the vehicle for selecting the speed, in particular a gas pedal, in the sense of increasing the speed.

9. The device according to claim 7, wherein the second operating mode is terminated when the device detects that

the longitudinal speed of the vehicle exceeds the setpoint speed by less than the preselectable extent, or

a time limit on the second operating mode is exceeded, or

the driver reduces the setpoint speed by actuating operating elements, or

the driver deactivates the system for setting the speed by actuating at least one operating element for deactivation of the system or by actuating a braking device, or

an obstacle is in the same lane as the vehicle, its distance being less than a preselectable distance.

10. The device according to claim 7, wherein when the second operating mode prevails and simultaneously the system detects that the vehicle is driving downhill, the device performs a braking measure, its delay moment depending on the gradient of the downhill segment of road, in particular when the negative road resistance is greater than the drag on the vehicle engine.