Method for optimizing a braking sequence

• US 7,401,868 B2
• Filed: 01/10/2006
• Issued: 07/22/2008
• Est. Priority Date: 07/10/2003
• Status: Active Grant

• Current Assignee: Volvo Lastvagnar AB (AB Volvo)
• Original Assignee: Volvo Lastvagnar AB (AB Volvo)
• Inventors: Steen, Marcus, Eriksson, Anders
• Primary Examiner(s): RODRIGUEZ, PAMELA
• Application Number:
  US11/306,761
• Publication Number:
  US 20060279137A1
• Time in Patent Office: 924 Days
• Field of Search: 303/20, 303/191, 303/177, 303/141, 303/142, 701/91, 701/93, 701/70, 701/36, 701/94, 701/95, 701/96, 701/98, 180/170, 180/178, 180/197
• US Class Current: 303/20
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• 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 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 10/11 Stepped gearings
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 10/196 acting within the driveline, e.g. retarders
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle
• CPC Class Codes: B60W 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: F16H 2061/022 Calculation or estimation of optimal gear ratio, e.g. best ratio for economy drive or performance according driver preference, or to optimise exhaust emissions
• CPC Class Codes: F16H 61/682 with interruption of drive

Abstract

A method for optimizing a braking sequence in a vehicle with automatic transmission (3) and gearbox (9) and automatic cruise control, which cruise control controls acceleration and braking to achieve a set speed, taking into account the distance to the vehicle in front. Data simulations are carried out continually of how the vehicle will be driven in the future, for a set of different combinations of engine speed at which a gear change takes place, gear change step and braking sequence, and a braking sequence with associated gear change schedule is selected that will be optimal. The vehicle is equipped with at least two different braking systems, for example service brake and auxiliary brake (48, 6). The system selects to brake primarily with the braking system that has the least tendency to wear.

Claims

1. A method for optimizing a braking sequence in a vehicle with automatic transmission (3) and gearbox (9), automatic cruise control, and at least two different braking systems (48, 6), said method comprising:

controlling acceleration and braking using the automatic cruise control to achieve a set speed;

taking into account the distance to the vehicle in front;

using a computer program for conducting data simulations on a continuous basis of how the vehicle will be driven in the future in consideration of at least a set of different combinations of engine speed at which a gear change takes place, a gear change schedule and the braking sequence; and

selecting the braking sequence with associated gear change schedule that will be optimal for the given conditions;

wherein when selecting the gear change schedule and braking sequence, the cruise control chooses to brake primarily with the braking system (48, 6) that has the least tendency to wear.

2. The method as recited in claim 1, wherein the braking system comprises at least one service brake and at least one auxiliary brake (48, 6).

3. The method as recited in claim 1, wherein the braking force from an auxiliary brake (48, 6) is dependent upon the gear selected in the gearbox (9).

4. The method as recited in claim 1, wherein the braking sequence is optimized in such a way that an even and sufficient retardation for a predetermined final speed is obtained.

5. The method as recited in claim 1, wherein a current vehicle position is determined by means of a position determination system (330, 340) which is connected to a control unit (45) for determination of the current position of the vehicle.

6. The method as recited in claim 1 wherein the computer program comprises program code that is executed by a computer.

7. The method as recited in claim 1, wherein the computer program comprises program code stored on a medium that can be read by a computer.

8. The method as recited in claim 1, wherein the computer program is loaded directly into an internal memory in a digital computer.