Telematics devices and methods for vehicle ignition detection

Patent metadata

Field	Value
Publication number	US-2017200329-A1
Application number	US-201715471473-A
Country	US
Kind code	A1
Filing date	Mar 28, 2017
Priority date	Sep 29, 2014
Publication date	Jul 13, 2017
Grant date	—

Abstract

Exemplary embodiments are provided of telematics devices and exemplary corresponding methods. In an exemplary embodiment, a telematics device generally includes a controller, a wireless communication module to transmit ignition information to a remote station, a power input terminal to sense a voltage of the battery, and an ignition input terminal to couple to an ignition line of the vehicle. The controller determines whether the ignition input terminal is coupled to an ignition line of the vehicle, and when the terminal is coupled to an ignition line, the controller determines vehicle ignition turn on and ignition turn off events by detecting voltage changes on the ignition line. When the ignition input terminal is not coupled to an ignition line of the vehicle, the controller senses the voltage of the battery of the vehicle to determine vehicle ignition turn on and turn off events based on sensed voltage changes of the battery.

First claim

1 . A telematics device, comprising:
a controller; a wireless communication module coupled to the controller, the wireless communication module configured to transmit ignition information from the controller to a remote station; a power input terminal configured to couple to a battery of a vehicle to sense a voltage of the battery; and an ignition input terminal configured to couple to an ignition line of the vehicle; wherein the controller is configured to:
determine whether the ignition input terminal is coupled to an ignition line of the vehicle;
when the ignition input terminal is coupled to an ignition line of the vehicle, determine vehicle ignition turn on and ignition turn off events by detecting voltage changes on the ignition line; and
when the ignition input terminal is not coupled to an ignition line of the vehicle, sense the voltage of the battery of the vehicle to determine vehicle ignition turn on and turn off events based on sensed voltage changes of the battery.

2 . The telematics device of claim 1 , wherein the controller is configured to determine whether the ignition input terminal is coupled to an ignition line of the vehicle by sensing a voltage of the ignition input terminal and determining whether the sensed ignition input voltage is above an ignition connection threshold.

3 . The telematics device of claim 1 , further comprising a ground terminal configured to couple to a ground of the vehicle.

4 . The telematics device of claim 3 , wherein the power input terminal is configured to connect to an on-board diagnostics port of the vehicle to sense the voltage of the battery, and the ground terminal is configured to couple to an on-board diagnostics port of the vehicle.

5 . The telematics device of claim 1 , wherein the controller is configured to determine an ignition turn on event when a sensed battery voltage increases by an amount that is greater than an ignition turn on threshold.

6 . The telematics device of claim 5 , wherein the controller is configured to determine the ignition turn on event by:
determining a prior battery voltage average by calculating an average of a plurality of previous voltage sample slots; comparing each of a plurality of most recent voltage sample slots to the prior battery voltage average; and when a threshold number of most recent voltage sample slots are above the prior battery voltage average by at least the ignition turn on threshold, determine that an ignition turn on event has occurred.

7 . The telematics device of claim 5 , wherein the ignition turn on threshold is about 0.5 volts.

8 . The telematics device of claim 1 , wherein the controller is configured to determine an ignition turn off event when a sensed battery voltage decreases by an amount that is greater than an ignition turn off threshold.

9 . The telematics device of claim 8 , wherein the controller is configured to determine an ignition turn off event by:
determining a prior battery voltage average by calculating an average of a plurality of previous voltage sample slots; comparing each of a plurality of most recent voltage sample slots to the prior battery voltage average; and when a threshold number of most recent voltage sample slots are below the prior battery voltage average by at least the ignition turn off threshold, determine that an ignition turn off event has occurred.

10 . The telematics device of claim 6 , wherein the ignition turn off threshold is about 0.5 volts.

11 . A method of detecting ignition events of a vehicle using a telematics device having a controller, a wireless communication module, a power input terminal configured to couple to a battery of a vehicle to sense a voltage of the battery, and an ignition input terminal configured to couple to an ignition line of the vehicle, the method comprising:
determining whether the ignition input terminal is coupled to an ignition line of the vehicle; when the ignition input terminal is coupled to an ignition line of the vehicle, determining ignition turn on and ignition turn off events by detecting voltage changes on the ignition line; and when the ignition input terminal is not coupled to an ignition line of the vehicle, sensing a voltage of a battery of the vehicle to determine ignition turn on and turn off events based on voltage changes of the battery.

12 . The method of claim 11 , wherein sensing a voltage of the battery includes repeatedly sensing a voltage sample of the battery after a time period, and storing the sensed voltages in slots of a moving array.

13 . The method of claim 12 , wherein the moving array includes about 20 slots, and each slot includes an average of about eight voltage samples taken at about 250 millisecond intervals.

14 . The method of claim 13 , further comprising:
determining a prior battery voltage average by calculating an average of a plurality of the oldest slots in the array; comparing each of a plurality of the most recent slots to the prior battery voltage average; when a threshold number of the most recent slots are above the prior battery voltage average by at least an ignition turn on threshold, determining that an ignition turn on event has occurred; and when a threshold number of the most recent slots are below the prior battery voltage average by at least an ignition turn off threshold, determining that an ignition turn off event has occurred.

15 . The method of claim 14 , wherein the prior battery voltage average is an average of the four oldest slots, the plurality of most recent slots includes the most recent six slots, and the threshold number of the most recent slots is at least four slots.

16 - 20 . (canceled)

Assignees

• Laird Technologies Inc

Inventors

• Rajakondala Balachander

Classifications

• G07C5/008 Primary

  communicating information to a remotely located station (transmission systems for measured values G08C) · CPC title

• G07C5/0816

  Indicating performance data, e.g. occurrence of a malfunction · CPC title

• G07C5/085

  using electronic data carriers · CPC title

• G01P1/103

  by comparing the value of the measured signal with one or several reference values (in general G01R17/00) · CPC title

• G01S19/13

  Receivers · CPC title