Granted Patent B2

US 10,295,559 · App. 14/501,276 · Granted May 21, 2019

Abstract

Claims (38)

1. A method comprising:

flipping an accelerometer attached to a rotating member from a first position to a second position as the rotating member rotates through multiple rotation periods;

receiving a first set of measurements from the accelerometer attached to the rotating member as the rotating member rotates through multiple rotation periods at the first position and the second position;

calibrating the accelerometer based on the first set of measurements corresponding to the first position and the second position of the accelerometer, wherein calibrating the accelerometer comprises:

determining a first difference between a first local maximum and a first local minimum of the first set of measurements;

determining a second difference between a second local maximum and the first local minimum of the first set of measurements;

determining a sensitivity value of the accelerometer based on an average of the first difference and the second difference; and

adjusting a second set of measurements based on the sensitivity value; and

localizing the rotating member based on the adjusted second set of measurements.

2. The method of claim 1 , wherein calibrating the accelerometer comprises:

accounting for a centrifugal force applied to the accelerometer based in part on the second local maximum.

3. The method of claim 2 , further comprising:

identifying the second local maximum as the local maximum of a rotation period immediately following a rotation period of the first local maximum.

4. The method of claim 3 further comprising:

determining a set of initial sensitivity values calculated based on a plurality of local maximums and local minimums including the first local minimum, the first local maximum, and the second local maximum; and wherein

calibrating the accelerometer comprises calibrating the accelerometer based on an average of the set of initial sensitivity values.

5. The method of claim 4 , wherein calibrating the accelerometer comprises:

determining an adjustment based on a rotation period of the rotating member;

adjusting the average of the set of initial sensitivity values based on the adjustment; and

calibrating the accelerometer based on the adjusted average.

6. The method of claim 1 , further comprising:

determining a consistency of the first set of measurements; and

repeating calibration of the accelerometer in response to the consistency being lower than a threshold.

7. The method of claim 1 , wherein the rotating member comprises a tire.

8. A method, comprising:

rotating a member through a plurality of rotation periods, the member being attached to an accelerometer;

flipping the accelerometer from at least a first position to a second position while rotating;

determining, at the first position and the second position of the accelerometer, a first plurality of acceleration measurements over the plurality of rotation periods;

calibrating the accelerometer based on the first plurality of acceleration measurements, wherein calibrating the accelerometer comprises:

determining a first difference between a first local maximum and a first local minimum of the acceleration measurements;

determining a second difference between a second local maximum and the first local minimum of the acceleration measurements; and

adapting a second plurality of acceleration measurements based on an average of the first difference and the second difference; and

localizing the member based on the calibrated accelerometer.

9. The method of claim 8 , wherein calibrating the accelerometer further comprises:

calibrating the accelerometer based on a centrifugal force accounted for by the first plurality of acceleration measurements.

10. The method of claim 8 , wherein:

the member comprises a vehicle tire; and

rotating the member comprises turning the vehicle tire by driving a vehicle including the vehicle tire.

Assignments (10)