Methods for determining the direction of rotation of rotating bodies

• US 7,487,670 B2
• Filed: 04/19/2006
• Issued: 02/10/2009
• Est. Priority Date: 04/19/2005
• Status: Active Grant

• Current Assignee: Continental Automotive Systems US Incorporated (Continental AG)
• Original Assignee: Siemens AG
• Inventors: Nelles, Oliver, Fink, Alexander
• Primary Examiner(s): Kwok; Helen C.
• Application Number:
  US11/406,703
• Publication Number:
  US 20060235641A1
• Time in Patent Office: 1,028 Days
• Field of Search: 735/09, 731/465, 731/463, 738/659, 702/151, 340440-445, 340/671, 701 41- 47, 701 26- 29, 701/37, 701/65, 701/70
• US Class Current: 73/146.5
• CPC Class Codes: B60C 23/0416 allocating a corresponding wheel position on vehicle, e.g. front/left or rear/right
• CPC Class Codes: G01P 13/04 Indicating positive or negative direction of a linear movement or clockwise or anti-clockwise direction of a rotational movement

Abstract

A method determines a direction of rotation of a rotating body about its axis of rotation by measuring two acceleration signals x and y with an acceleration sensor. The two acceleration signals x and y are at a 90° angle to each other, are oriented not parallel to the axis of rotation, and both a centrifugal acceleration generated by a circular movement and a gravitational acceleration are taken into account. The measured acceleration signals x and y are differentiated mathematically. The differentiated x acceleration signal is differentiated a further time and correlated with a y signal that has been differentiated once for obtaining a correlation function. The differentiated y acceleration signal can be differentiated a further time and correlated with the x signal that has been differentiated once for obtaining a second correlation function. The method determines the direction of rotation of rotating tires of a motor vehicle.

Claims

1. A method for determining a direction of rotation of a rotating body about an axis of rotation, which comprises the steps of:

measuring two acceleration signals x and y with at least one acceleration sensor resulting in measured acceleration signals x and y, the two acceleration signals x and y being at a 90 degree angle to each other and oriented not parallel to the axis of rotation, and both a centrifugal acceleration generated by a circular movement and a gravitational acceleration g being taken into account;

differentiating mathematically the measured acceleration signals x and y resulting in a differentiated x acceleration signal and a differentiated y acceleration signal;

differentiating a further time at least one of the differentiated x acceleration signal and the differentiated y acceleration signal resulting in a further differentiated x acceleration signal and/or a further differentiated y acceleration signal; and

performing at least one of;

correlating the further differentiated x acceleration signal with the differentiated y acceleration signal for obtaining a first correlation function; and

correlating the further differentiated y acceleration signal with the differentiated x acceleration signal for obtaining a second correlation function.

2. The method according to claim 1, which further comprises:

performing both of the correlating steps for obtaining the first and second correlation functions; and

using the first and second correlation functions in a common evaluation procedure.

3. The method according claim 1, which further comprises:

performing both of the correlating steps for obtaining the first and second correlation functions; and

determining a difference between the first and second correlation functions.

4. The method according to claim 1, which further comprises approximating a differentiation by use of a difference quotient.

5. The method according to claim 1, which further comprises:

performing both of the correlating steps for obtaining the first and second correlation functions; and

calculating integrals of the first and second correlation functions in an approximation by use of a sum total.

6. The method according to claim 1, wherein the rotating body is a tire of a motor vehicle.

7. A method for determining a direction of rotation of a rotating body about an axis of rotation, which comprises the steps of:

measuring two acceleration signals x and y with at least one acceleration sensor resulting in measured acceleration signals x and y, the two acceleration signals x and y being at a 90 degree angle to each other and oriented not parallel to the axis of rotation, and both a centrifugal acceleration generated by a circular movement and a gravitational acceleration g being taken into account;

differentiating mathematically the measured acceleration signals x and y resulting in a differentiated x acceleration signal and a differentiated y acceleration signal;

differentiating a further time the differentiated y acceleration signal resulting in a further differentiated y acceleration signal; and

correlating the further differentiated y acceleration signal with the differentiated x acceleration signal for obtaining a correlation function.

8. A method for determining a direction of rotation of a rotating body about an axis of rotation, which comprises the steps of:

measuring two acceleration signals x and y with at least one acceleration sensor resulting in measured acceleration signals x and y, the two acceleration signals x and y being at a 90 degree angle to each other and oriented not parallel to the axis of rotation, and both a centrifugal acceleration generated by a circular movement and a gravitational acceleration g being taken into account;

differentiating mathematically the measured acceleration signals x and y resulting in a differentiated x acceleration signal and a differentiated y acceleration signal;

differentiating a further time the differentiated x acceleration signal resulting in a further differentiated x acceleration signal; and

correlating the further differentiated x acceleration signal with the differentiated y acceleration signal for obtaining a correlation function.