Method for controlling the speed of a vehicle

• US 20050065704A1
• Filed: 11/05/2003
• Published: 03/24/2005
• Est. Priority Date: 11/06/2002
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Glora, Michael
• Granted Patent: US 7,133,760 B2
• Time in Patent Office: Days
• US Class Current: 701/93
• 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 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: F16H 2061/0237 Selecting ratios for providing engine braking
• CPC Class Codes: F16H 61/0213 characterised by the method for generating shift signals
• CPC Class Codes: F16H 61/21 Providing engine brake control

Abstract

A method is directed to the control of the speed of a vehicle wherein the actual speed is caused to track the desired speed. For reducing the actual speed, a transmission (1) of the vehicle (5) is driven to downshift and thereby the brake system is protected with respect to wear and overheating.

Claims

1. A method for controlling the speed of a vehicle, the method comprising the steps of:

causing the actual speed of said vehicle to track a desired speed; and

,

driving a transmission of said vehicle to downshift to reduce said actual speed.

2. The method of claim 1, comprising the further step of additionally driving a brake system of said vehicle to reduce said actual speed.

3. The method of claim 2, comprising the further step of driving said brake system when an output quantity of a drive unit of said vehicle lies below a first value adjusted for an overrun operation in the instantaneous gear stage of said transmission.

4. The method of claim 3, wherein said output quantity is a drive torque.

5. The method of claim 3, comprising the further step of driving said transmission to downshift when said output quantity of said drive unit drops below a second value which can be expected to adjust for the overrun operation in the next lower gear stage.

6. The method of claim 2, comprising the further step of driving said transmission to downshift after a pregiven time after the start of driving said brake system to reduce said actual speed.

7. The method of claim 2, comprising the further step of driving said transmission for downshifting in dependence upon an accelerator pedal value.

8. The method of claim 7, comprising the further step of iteratively increasing said accelerator pedal value for a requested downshifting of said transmission.

9. The method of claim 7, wherein said accelerator pedal value is changed in dependence upon a difference between an initial deceleration request when activating said brake system and an instantaneous deceleration request of said brake system.