Systems and methods for sensor-based detection and alerting of hard braking events

1. A method comprising:

receiving, by one or more processors, electronic signals generated by one or more sensors of a mobile device disposed in a vehicle during a drive, wherein the electronic signals indicate motion data measured in a reference frame of the mobile device;

transforming, by the one or more processors, the motion data measured in the reference frame of the mobile device to produce acceleration vectors for the vehicle in a reference frame of the vehicle;

detecting, by the one or more processors using the acceleration vectors for the vehicle, a hard braking event;

detecting, by the one or more processors using the motion data, and the acceleration vectors for the vehicle, movement of the mobile device with respect to the reference frame of the vehicle indicating a distracted driving event;

detecting, by the one or more processors, a correlation between the distracted driving event and the hard braking event, wherein the correlation indicates that the hard braking event was in response to the distracted driving event;

alerting, by the one or more processors, a user of the mobile device, through the mobile device, of the hard braking event and the distracted driving event in real time in response to detecting the correlation, wherein the user is alerted at a first time;

detecting a subsequent correlation between a subsequent distracted driving event and a subsequent hard braking event at a subsequent time during the drive;

determining that an elapsed time between the first time and the subsequent time is greater than or equal to a predefined period of time in response to detecting the subsequent correlation; and

alerting the user of the mobile device, through the mobile device, of the subsequent hard braking event and the subsequent distracted driving event in real time in response to determining that the elapsed time is greater than or equal to the predefined period of time.

2. The method of claim 1 wherein the user of the mobile device is alerted of the subsequent hard braking event and the subsequent distracted driving event in further response to determining that a predefined number of events have been detected between the first time and the subsequent time, and wherein the predefined number of events is set on the mobile device or received from a server.

3. The method of claim 1 wherein the predefined period of time is received from a server.

4. The method of claim 1 further comprising:

receiving, before the first time, a first input from the user of the mobile device that enables alerts, wherein the user is alerted at the first time in further response to determining that the alerts are enabled; or

receiving, after the drive is complete, a second input from the user of the mobile device that disables future alerts.

5. The method of claim 1 wherein the predefined period of time is set based on an input from the user of the mobile device.

6. The method of claim 1 wherein the motion data is collected during an initial time period that includes the first time and the subsequent time, the method further comprising:

collecting additional motion data from the one or more sensors of the mobile device during a subsequent time period, wherein the subsequent time period is after the initial time period;

detecting, using the additional motion data and at least one of the one or more processors or a server, a change in a rate of hard braking events during the subsequent time period; and

modifying future alerts based on the detection of the change in the rate of hard braking events during the subsequent time period.

7. The method of claim 6 wherein modifying the future alerts comprises modifying a timing of notifying the user of a future hard braking event.

8. The method of claim 1 wherein alerting the user of the hard braking event and the distracted driving event comprises delivery, using the mobile device, of at least one of an audio alert or a haptic alert.

9. The method of claim 8 further comprising, concurrent with delivery of the audio alert or the haptic alert, delivering, using the mobile device, a visual alert.

10. The method of claim 1 wherein the one or more sensors of the mobile device comprises an accelerometer and detecting the hard braking event comprises detecting a rapid deceleration of the vehicle using acceleration vectors for the vehicle determined from the motion data.

11. The method of claim 1 further comprising processing, using at least one of the one or more processors or a server, the motion data to identify the vehicle as a motor vehicle.

12. The method of claim 11 further comprising processing, using at least one of the one or more processors or the server, the motion data to determine that the user of the mobile device is driving the motor vehicle.

13. The method of claim 12 wherein determining that the user of the mobile device is driving comprises processing the motion data to determine that the mobile device is located in a front of the motor vehicle, that the mobile device entered the motor vehicle from a driver side, or both.

14. A mobile device comprising:

a memory;

a motion data unit comprising one or more sensors configured to generate electronic signals indicative of motion data measured in a reference frame of the mobile device; and

a processor coupled to the memory, wherein the processor is configured to perform operations including:

receiving the electronic signals from the motion data unit while the mobile device is disposed in a vehicle during a drive;

transforming, from the electronic signals, the motion data measured in the reference frame of the mobile device to produce acceleration vectors for the vehicle in a reference frame of the vehicle;

detecting, using the acceleration vectors for the vehicle, a hard braking event;

detecting, using the motion data and the acceleration vectors for the vehicle, movement of the mobile device with respect to the reference frame of the vehicle indicating a distracted driving event;

detecting a correlation between the distracted driving event and the hard braking event, wherein the correlation indicates that the hard braking event was in response to the distracted driving event;

alerting a user of the mobile device, through the mobile device, of the hard braking event and the distracted driving event in real time in response to detecting the correlation, wherein the user is alerted at a first time;

detecting a subsequent correlation between a subsequent distracted driving event and a subsequent hard braking event at a subsequent time during the drive;

determining that an elapsed time between the first time and the subsequent time is greater than or equal to a predefined period of time in response to detecting the subsequent correlation; and

alerting the user of the mobile device, through the mobile device, of the subsequent hard braking event and the subsequent distracted driving event in real time in response to determining that the elapsed time is greater than or equal to the predefined period of time.

15. The mobile device of claim 14 wherein the motion data is collected during an initial time period that includes the first time and the subsequent time, the operations further comprising:

receiving additional motion data from the one or more sensors of the mobile device during a subsequent time period, wherein the subsequent time period is after the initial time period;

detecting, using the additional motion data, a change in a rate of hard braking events during the subsequent time period; and

modifying future alerts based on the detection of the change in the rate of hard braking events during the subsequent time period.

16. The mobile device of claim 15 wherein modifying the future alerts comprises modifying a timing of notifying the user of a future hard braking event.

17. The mobile device of claim 14 wherein alerting the user of the hard braking event and the distracted driving event comprises delivery, using the mobile device, of at least one of an audio alert or a haptic alert.

18. The mobile device of claim 17 wherein the operations further comprise, concurrent with delivery of the audio alert or the haptic alert, delivering, using the mobile device, a visual alert.

19. The mobile device of claim 14 wherein the one or more sensors of the mobile device comprises an accelerometer and detecting the hard braking event comprises detecting a rapid deceleration of the vehicle using acceleration vectors for the vehicle determined from the motion data.

20. The mobile device of claim 14 wherein the operations further comprise processing the motion data to determine that the user of the mobile device is driving vehicle by:

determining that the mobile device is located in a front of the vehicle;

determining a yaw of the mobile device during vehicle entry; and

determining that the mobile device entered the vehicle from a driver side of the vehicle.