Method and device for determining a vehicle inertial position

• US 6,259,999 B1
• Filed: 03/23/1999
• Issued: 07/10/2001
• Est. Priority Date: 07/25/1997
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Pantle, Markus
• Primary Examiner(s): ASSOUAD, PATRICK J
• Application Number:
  US09/147,905
• Time in Patent Office: 840 Days
• Field of Search: 702/153, 702/141, 73/514.01, 701/1, 701/36, 701/38
• US Class Current: 702/153
• CPC Class Codes: B60R 2021/0018 Roll-over
• CPC Class Codes: B60R 2021/01306 monitoring vehicle inclination
• CPC Class Codes: B60R 2021/01322 comprising variable thresholds, e.g. depending from other collision parameters
• CPC Class Codes: B60R 2021/01325 Vertical acceleration
• CPC Class Codes: B60R 21/013 including means for detecting collisions, impending collisions or roll-over
• CPC Class Codes: B60R 21/01338 using vector analysis
• CPC Class Codes: G01C 9/08 Means for compensating acceleration forces due to movement of instrument

Abstract

The inertial state can be determined independently of dynamic vehicle movements by measuring the accelerations of the vehicle in the direction of its longitudinal, transverse and vertical axes, by forming the magnitude of an acceleration vector resulting from the three acceleration components and comparing the magnitude of the acceleration vector through threshold decisions with a window that is delimited by a threshold lying above and a threshold lying below gravitational acceleration g. A current course angle of the vehicle with respect to its longitudinal axis and/or the current course angle with respect to its transverse axis is then determined only if the magnitude of the acceleration vector lies inside the window; otherwise, however, the previously determined course angles are retained.

Claims

1. A method for determining an inertial state of a vehicle, comprising the steps of:

(a) measuring a first acceleration component of the vehicle in a first direction, a second acceleration component of the vehicle in a second direction and a third acceleration component of the vehicle in a third direction, the first direction extending along a longitudinal axis of the vehicle, the second direction extending along a transverse axis of the vehicle and the third direction extending along a vertical axis of the vehicle;

(b) obtaining a magnitude of an acceleration vector of the vehicle as a function of the first, second and third acceleration components;

(c) determining if the magnitude is within a predetermined threshold range using a threshold decision arrangement, the predetermined threshold range having an upper threshold value which is greater than a gravitational acceleration value and a lower threshold value which is less than the gravitational acceleration value;

(d) only if the magnitude is within the predetermined threshold range, determining at least one of a first current course angle of the vehicle with respect to the longitudinal axis and a second current course angle of the vehicle with respect to the transverse axis; and

(e) if the magnitude is outside of the predetermined threshold range, retaining at least one of a first previously determined course angle with respect to the longitudinal axis and a second previously determined course angle with respect to the transverse axis.

2. The method according to claim 1, wherein the upper threshold value is approximately 10% greater than the gravitational acceleration value and the lower threshold value is approximately 10% less than the gravitational acceleration value.

3. The method according to claim 1, wherein step (c) includes the substep of determining if a further magnitude of a further acceleration vector is within the predetermined threshold range using the threshold decision arrangement, the further acceleration vector being formed before the acceleration vector, and wherein step (d) includes the substep of determining at least one of the first current course angle and the second current course angle if the magnitude and the further magnitude are within the predetermined threshold range.

4. The method according to claim 1, further comprising the steps of:

(f) determining a first corresponding component of the first and second current course angles as a function of the first, second and third acceleration components;

(g) determining a second corresponding component of at least one of the first and second previously determined course angles; and

(h) recursively determining at least one of the first and second current course angles as a function of the first and second corresponding components.

5. The method according to claim 1, further comprising the step of:

(i) determining at least one of a first rotational angle with respect to the longitudinal axis and a second rotational angle with respect to the transverse axis as a function of an integration of at least one measured rate of rotation, wherein the integration is performed using at least one of the first current course angle, the second current course angle, the first previously determined course angle, and the second previously determined course angle.

6. An arrangement for determining an inertial state of a vehicle, comprising:

acceleration sensors measuring a first acceleration component of the vehicle in a first direction, a second acceleration component of the vehicle in a second direction and a third acceleration component of the vehicle in a third direction, the first direction extending along a longitudinal axis of the vehicle, the second direction extending along a transverse axis of the vehicle and the third direction extending along a vertical axis of the vehicle;

a first arrangement determining a magnitude of an acceleration vector as a function of the first, second and third acceleration components;

a second arrangement determining if the magnitude is within a predetermined threshold range, the predetermined threshold range having an upper threshold value which is greater than a gravitational acceleration value and a lower threshold value which is less than the gravitational acceleration value; and

a third arrangement determining at least one of a first current course angle of the vehicle with respect to the longitudinal axis and the second current course angle of the vehicle with respect to the transverse axis only if the magnitude is within the predetermined threshold range, wherein, if the magnitude is outside of the predetermined threshold range, then at least one of a first previously determined course angle with respect to the longitudinal axis and a second previously determined course angle with respect to the transverse axis is retained.