Method and system for cargo mass estimation using a vertical accelerometer

1. A method for cargo mass estimation using a sensor apparatus affixed to a transportation asset, the method comprising:

calibrating the sensor apparatus by initiating a vertical impact at the transportation asset, wherein the calibrating step comprises measuring a first spring oscillation and creating a model of the transportation asset;

detecting, subsequent to the calibrating, an impact event at the sensor apparatus;

determining that a trigger condition exists, wherein the trigger condition is one or more of: a door open event; a door close event; or a threshold time period in which the transportation asset is stationary;

in response to determining that the trigger condition exists, measuring a second spring oscillation due to the impact event at the sensor apparatus; and

using the measured second spring oscillation in the model created during calibration to create a load mass estimate for the transportation asset;

wherein initiating the vertical impact comprises driving the transportation asset while empty over a vertical curb, the vertical curb having a length of at least three inches.

2. The method of claim 1 , wherein the step of measuring the second spring oscillation comprises:

sending a signal from a vertical accelerometer in the sensor apparatus to wake a processor of the sensor apparatus; and

recording, using the processor of the sensor apparatus, oscillations detected by the vertical accelerometer.

3. The method of claim 2 , wherein the recording is for a predetermined time period.

4. The method of claim 1 , wherein the model is created with a plurality of oscillations based on one or more of: dampers; shock absorbers; air bags; multiple axles; or tractor coupling.

5. The method of claim 1 , wherein the calibrating uses an empty transportation asset mass looked up by the sensor apparatus.

6. The method of claim 1 , further comprising:

using the measured second spring oscillation over a time period to detect deterioration of components within the transportation asset.

7. The method of claim 1 , further comprising comparing the load mass estimate with an expected load mass to determine anomalies.

8. A sensor apparatus affixed to a transportation asset, the sensor apparatus comprising:

a processor; and

a communications subsystem,

wherein the processor and the communications subsystem cooperate to:

calibrate the sensor apparatus by initiating a vertical impact at the transportation asset, wherein the calibrating step comprises measuring a first spring oscillation and creating a model of the transportation asset;

detect, subsequent to the calibrating, an impact event at the sensor apparatus;

determine that a trigger condition exists, wherein the trigger condition is one or more of: a door open event; a door close event; or a threshold time period in which the transportation asset is stationary;

in response to determining that the trigger condition exists, measure a second spring oscillation due to the impact event at the sensor apparatus; and

use the measured second spring oscillation in the model created during calibration to create a load mass estimate for the transportation asset;

wherein initiating the vertical impact comprises driving the transportation asset while empty over a vertical curb, the vertical curb having a length of at least three inches.

9. The sensor apparatus of claim 8 , wherein the sensor apparatus is configured to measure the second spring oscillation by:

sending a signal from a vertical accelerometer in the sensor apparatus to wake a processor of the sensor apparatus; and

recording, using the processor of the sensor apparatus, oscillations detected by the vertical accelerometer.

10. The sensor apparatus of claim 9 , wherein the sensor apparatus is configured to record for a predetermined time period.

11. The sensor apparatus of claim 8 , wherein the sensor apparatus is configured to create the model with a plurality of oscillations based on one or more of: dampers; shock absorbers; air bags; multiple axles; or tractor coupling.

12. The sensor apparatus of claim 8 , wherein the sensor apparatus is configured to calibrate using an empty transportation asset mass looked up by the sensor apparatus.

13. The sensor apparatus of claim 8 , wherein the sensor apparatus is configured to:

use the measured second spring oscillation over a time period to detect deterioration of components within the transportation asset.

14. The sensor apparatus of claim 8 , wherein the sensor apparatus is configured to compare the load mass estimate with an expected load mass to determine anomalies.

15. A computer readable medium for storing instruction code, which, when executed by a processor of a sensor apparatus affixed to a transportation asset, causes the sensor apparatus to:

calibrate the sensor apparatus by initiating a vertical impact at the transportation asset, wherein the calibrating step comprises measuring a first spring oscillation and creating a model of the transportation asset;

detect, subsequent to the calibrating, an impact event at the sensor apparatus;

determine that a trigger condition exists, wherein the trigger condition is one or more of: a door open event; a door close event; or a threshold time period in which the transportation asset is stationary;

in response to determining that the trigger condition exists, measure a second spring oscillation due to the impact event at the sensor apparatus; and

use the measured second spring oscillation in the model created during calibration to create a load mass estimate for the transportation asset;

wherein initiating the vertical impact comprises driving the transportation asset while empty over a vertical curb, the vertical curb having a length of at least three inches.