Data synchronization across multiple sensors

• US 10,285,141 B1
• Filed: 09/19/2012
• Issued: 05/07/2019
• Est. Priority Date: 09/19/2012
• Status: Active Grant

• Current Assignee: Liberty Mutual Insurance Company (Liberty Mutual Holding Company)
• Original Assignee: Safeco Insurance Company of America (Liberty Mutual Holding Company)
• Inventors: Carver, Christopher J.
• Primary Examiner(s): Satanovsky, Alexander
• Assistant Examiner(s): Cordero, Lina M
• Application Number:
  US13/622,793
• Time in Patent Office: 2,421 Days
• Field of Search: 702150
• CPC Class Codes: A61B 5/0015 characterised by features of the telemetry system
• CPC Class Codes: H04L 7/00 Arrangements for synchronising receiver with transmitter synchronisation of generators of electric oscillations or pulses H03L7/00
• CPC Class Codes: H04Q 2209/845 where the measuring is synchronized between sensing devices
• CPC Class Codes: H04Q 9/04 Arrangements for synchronous operation
• CPC Class Codes: H04W 56/00 Synchronisation arrangements

Abstract

Various embodiments of the present invention provide methods, systems, apparatus, and computer program products for synchronizing data across at least two sensors. In one embodiment, first sensor data, which includes a universal time stamp from a universal time source, is recorded from at least one first sensor and second sensor data, which does not include a universal time stamp from a universal time source, is recorded from at least one second sensor. The first sensor data is correlated with the second sensor data, and a universal time that corresponds with the data from the second sensor is determined at least in part based on the correlation between the first sensor data and the second sensor data.

Claims

1. A method of synchronizing data of at least one first vehicle sensor of a vehicle with data of at least one second vehicle sensor of the vehicle comprising:

recording, by a vehicle telematics device positioned in the vehicle and comprising one or more processors and one or more memory storage areas operatively connected to the one or more processors, first vehicle sensor data provided by the at least one first vehicle sensor operatively connected to the vehicle telematics device, wherein (a) the first vehicle sensor data comprises (i) a local time stamp based on a local time source indicating the time at which the first vehicle sensor data was recorded by the telematics device, (ii) a universal time stamp based on a universal time source indicating the time at which the first vehicle sensor data was measured by the at least one first vehicle sensor, (b) the at least one first vehicle sensor is synchronized to the universal time source, (c) the universal time source comprises a global navigation satellite system, (d) the local time stamp indicating the time at which the first vehicle sensor data was recorded by the telematics device comprises a delay from the universal time stamp indicating the time at which the first vehicle sensor data was measured by the at least one first vehicle sensor, and (e) the delay comprises at least one of a clock delay, a propagation delay, a computational delay, a buffering delay, a scheduling delay, a drift delay, and a processing delay;

recording, by the vehicle telematics device positioned in the vehicle, second vehicle sensor data provided by the at least one second vehicle sensor operatively connected to the vehicle telematics device, wherein the second vehicle sensor data comprises (a) a local time stamp based on the local time source indicating the time at which the second vehicle sensor data was recorded by the telematics device but (b) does not comprise a universal time stamp based on the universal time source indicating the time at which the second vehicle sensor data was measured by the at least one second vehicle sensor;

interpolating the first vehicle sensor data to generate additional first vehicle sensor data such that a time step of the first vehicle sensor data equals a time step of the second vehicle sensor data;

determining an orientation of the at least one second vehicle sensor;

adjusting the second vehicle sensor data based at least in part on the determined orientation;

converting the first vehicle sensor data from a first coordinate system associated with the first vehicle sensor data to a second coordinate system associated with the second vehicle sensor data based at least in part on the adjusted second vehicle sensor data;

transforming the first vehicle sensor data to convert the first vehicle sensor data from a first value measured by the at least one first vehicle sensor to a second value corresponding to a type of data measured by the at least one second vehicle sensor;

determining a time shift, by the vehicle telematics device positioned in the vehicle, between the first vehicle sensor data and the second vehicle sensor data by performing cross-correlation between the second vehicle sensor data and the first vehicle sensor data, wherein the first vehicle sensor data (1) has been converted to the second coordinate system associated with the second vehicle sensor data and (2) has been transformed to the second value corresponding to the type of data measured by the at least one second vehicle sensor;

in response to determining the time shift between the first vehicle sensor data and the second vehicle sensor data, synchronizing the first vehicle sensor data with the second vehicle sensor data by determining a universal time that corresponds to the second vehicle sensor data based at least in part on (a) the universal time stamp of the first vehicle sensor data, and (b) the time shift determined from the cross-correlation between the first vehicle sensor data and the second vehicle sensor data; and

in response to determining the universal time, recording, by the vehicle telematics device positioned in the vehicle, new first vehicle sensor data and new second vehicle sensor data, wherein the new first vehicle sensor data and second vehicle sensor data are each recorded in real time in association with the determined universal time based on the synchronization.

2. The method of claim 1 further comprising:

associating a universal time stamp corresponding to the determined universal time with the second vehicle sensor data.

3. The method of claim 1, wherein interpolating is selected from the group consisting of spline interpolation, linear interpolation, and polynomial interpolation.

4. A vehicle telematics device positioned in a vehicle and comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the processor, cause the vehicle telematics device to at least:

record first vehicle sensor data provided by at least one first vehicle sensor operatively connected to the vehicle telematics device, wherein (a) the first vehicle sensor data comprises (i) a local time stamp based on a local time source indicating the time at which the first vehicle sensor data was recorded by the telematics device, (ii) a universal time stamp based on a universal time source indicating the time at which the first vehicle sensor data was measured by the at least one first vehicle sensor, (b) the at least one first vehicle sensor is synchronized to the universal time source, (c) the universal time source comprises a global navigation satellite system, (d) the local time stamp indicating the time at which the first vehicle sensor data was recorded by the telematics device comprises a delay from the universal time stamp indicating the time at which the first vehicle sensor data was measured by the at least one first vehicle sensor, and (e) the delay comprises at least one of a clock delay, a propagation delay, a computational delay, a buffering delay, a scheduling delay, a drift delay, and a processing delay;

record second vehicle sensor data provided by at least one second vehicle sensor operatively connected to the vehicle telematics device, wherein the second vehicle sensor data comprises (a) a local time stamp based on the local time source indicating the time at which the second vehicle sensor data was recorded by the telematics device but (b) does not comprise a universal time stamp based on the universal time source indicating the time at which the second vehicle sensor data was measured by the at least one second vehicle sensor;

interpolate the first vehicle sensor data to generate additional first vehicle sensor data such that a time step of the first vehicle sensor data equals a time step of the second vehicle sensor data;

determine an orientation of the at least one second vehicle sensor;

adjust the second vehicle sensor data based at least in part on the determined orientation;

convert the first vehicle sensor data from a first coordinate system associated with the first vehicle sensor data to a second coordinate system associated with the second vehicle sensor data based at least in part on the adjusted second vehicle sensor data;

transform the first vehicle sensor data to convert the first vehicle sensor data from a first value measured by the at least one first vehicle sensor to a second value corresponding to a type of data measured by the at least one second vehicle sensor;

determine a time shift between the first vehicle sensor data and the second vehicle sensor data by performing cross-correlation between the second vehicle sensor data and the first vehicle sensor data, wherein the first vehicle sensor data (1) has been converted to the second coordinate system associated with the second vehicle sensor data and (2) has been transformed to the second value corresponding to the type of data measured by the at least one second vehicle sensor;

in response to determining the time shift between the first vehicle sensor data and the second vehicle sensor data, synchronize the first vehicle sensor data with the second vehicle sensor data by determining a universal time that corresponds to the second vehicle sensor data based at least in part on (a) the universal time stamp of the first vehicle sensor data, and (b) the time shift determined from the cross-correlation between the first vehicle sensor data and the second vehicle sensor data; and

in response to determining the universal time, record new first vehicle sensor data and new second vehicle sensor data, wherein the new first vehicle sensor data and second vehicle sensor data are each recorded in real time in association with the determined universal time based on the synchronization.

5. The vehicle telematics device of claim 4, wherein the memory and computer program code are further configured to, with the processor, cause the apparatus to at least:

associate a universal time stamp corresponding to the determined universal time with the second vehicle sensor data.

6. The vehicle telematics device of claim 4, wherein interpolating is selected from the group consisting of spline interpolation, linear interpolation, and polynomial interpolation.

7. A computer program product for synchronizing data of at least one first vehicle sensor of a vehicle with data of at least one second vehicle sensor of the vehicle, the computer program product comprising at least one non-transitory computer-readable storage medium having computer-readable program code portions stored therein, the computer-readable program code portions comprising:

an executable portion configured to record, by a vehicle telematics device positioned in the vehicle and comprising one or more processors and one or more memory storage areas operatively connected to the one or more processors, first vehicle sensor data provided by the at least one first vehicle sensor operatively connected to the vehicle telematics device, wherein (a) the first vehicle sensor data comprises (i) a local time stamp based on a local time source indicating the time at which the first vehicle sensor data was recorded by the telematics device, (ii) a universal time stamp based on a universal time source indicating the time at which the first vehicle sensor data was measured by the at least one first vehicle sensor, (b) the at least one first vehicle sensor is synchronized to the universal time source, (c) the universal time source comprises a global navigation satellite system, (d) the local time stamp indicating the time at which the first vehicle sensor data was recorded by the telematics device comprises a delay from the universal time stamp indicating the time at which the first vehicle sensor data was measured by the at least one first vehicle sensor, and (e) the delay comprises at least one of a clock delay, a propagation delay, a computational delay, a buffering delay, a scheduling delay, a drift delay, and a processing delay;

an executable portion configured to record, by the vehicle telematics device positioned in the vehicle, second vehicle sensor data provided by the at least one second vehicle sensor operatively connected to the vehicle telematics device, wherein the second vehicle sensor data comprises (a) a local time stamp based on the local time source indicating the time at which the second vehicle sensor data was recorded by the telematics device but (b) does not comprise a universal time stamp based on the universal time source indicating the time at which the second vehicle sensor data was measured by the at least one second vehicle sensor;

an executable portion configured to interpolate the first vehicle sensor data to generate additional first vehicle sensor data such that a time step of the first vehicle sensor data equals a time step of the second vehicle sensor data;

an executable portion configured to determine an orientation of the at least one second vehicle sensor;

an executable portion configured to adjust the second vehicle sensor data based at least in part on the determined orientation;

an executable portion configured to convert the first vehicle sensor data from a first coordinate system associated with the first vehicle sensor data to a second coordinate system associated with the second vehicle sensor data based at least in part on the adjusted second vehicle sensor data;

an executable portion configured to transform the first vehicle sensor data to convert the first vehicle sensor data from a first value measured by the at least one first vehicle sensor to a second value corresponding to a type of data measured by the at least one second vehicle sensor;

an executable portion configured to determine a time shift, by the vehicle telematics device positioned in the vehicle, between the first vehicle sensor data and the second vehicle sensor data by performing cross-correlation between the second vehicle sensor data and the first vehicle sensor data, wherein the first vehicle sensor data (1) has been converted to the second coordinate system associated with the second vehicle sensor data and (2) has been transformed to the second value corresponding to the type of data measured by the at least one second vehicle sensor;

an executable portion configured to, in response to determining the time shift between the first vehicle sensor data and the second vehicle sensor data synchronize the first vehicle sensor data with the second vehicle sensor data by determining a universal time that corresponds to the second vehicle sensor data based at least in part on (a) the universal time stamp of the first vehicle sensor data, and (b) the time shift determined from the cross-correlation between the first vehicle sensor data and the second vehicle sensor data; and

an executable portion configured to, in response to determining the universal time, record, by the vehicle telematics device positioned in the vehicle, new first vehicle sensor data and new second vehicle sensor data, wherein the new first vehicle sensor data and second vehicle sensor data are each recorded in real time and in association with the determined universal time based on the synchronization.

8. The computer program product of claim 7, further comprising:

an executable portion configured to associate a universal time stamp corresponding to the determined universal time with the second vehicle sensor data.

9. The computer program product of claim 7, wherein interpolating is selected from the group consisting of spline interpolation, linear interpolation, and polynomial interpolation.