Method for estimating the longitudinal inclination of a roadway

• US 20050125107A1
• Filed: 10/26/2004
• Published: 06/09/2005
• Est. Priority Date: 10/30/2003
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Grieser, Joerg, Schmidt, Mario
• Granted Patent: US 7,580,784 B2
• Time in Patent Office: Days
• US Class Current: 701/1
• CPC Class Codes: B60T 7/122 for locking of reverse movement
• CPC Class Codes: G01C 9/00 Measuring inclination, e.g. by clinometers, by levels

Abstract

A method and device for determining a longitudinal inclination variable representing the longitudinal inclination of a roadway, using sensor means present in a motor vehicle, in which a first unbraked driving state of the vehicle and a second driving state of the motor vehicle in which at least one brake is actuated are considered; and as a function thereof the variable representing the longitudinal inclination of the roadway is determined.

Claims

1. A method for determining a longitudinal inclination variable representing a longitudinal inclination of a roadway, using a sensor arrangement situated in a motor vehicle, the method comprising:

determining the variable representing the longitudinal inclination of the roadway as a function of a first unbraked driving state of the vehicle and of a second driving state of the vehicle in which at least one brake is actuated.

2. The method according to claim 1, further comprising:

determining a rough inclination variable representing a rough value of the longitudinal inclination of the roadway;

determining a value of the longitudinal inclination variable by adding a correction term to the rough inclination variable; and

determining the correction term as a function of the first and second driving states.

3. The method according to claim 2, further comprising:

in the first driving state, determining a first difference between a vehicle longitudinal acceleration determined by a model and a vehicle longitudinal acceleration determined by evaluating wheel speed sensor signals;

in the second driving state, determining a second difference between a vehicle longitudinal acceleration determined by a model and a vehicle longitudinal acceleration determined by evaluating wheel speed sensor signals; and

determining the correction term as a function of the first and second differences.

4. The method according to claim 3, further comprising using a difference between the second difference and the first difference in determining the correction term.

5. The method according to claim 1, further comprising using at least wheel cylinder brake pressure and a drive torque of the vehicle in determining the longitudinal acceleration of the vehicle in the first and second driving states, using a model.

6. The method according to claim 1, wherein the first and second driving states are driving states which occur close to one another in time.

7. The method according to claim 2, wherein the rough inclination variable is determined at least from wheel cylinder brake pressures, a drive torque of the vehicle, and a longitudinal acceleration of the vehicle determined using output signals from wheel speed sensors.

8. The method according to claim 2, further comprising:

continuously determining the longitudinal inclination variable during unbraked and braked driving states while keeping the correction term constant; and

redetermining and updating the correction term when a transition from a braked to an unbraked driving state occurs.

9. A device for determining a longitudinal inclination variable representing a longitudinal inclination of a roadway, using a sensor arrangement situated in a motor vehicle, the device comprising:

an evaluation device in which a first unbraked driving state of the vehicle and a second driving state of the vehicle, in which at least one brake is actuated, are considered; and

means for determining the longitudinal inclination, in which the variable representing the longitudinal inclination of the roadway is determined as a function of output signals from the evaluation device.