Apparatus and method for monitoring vehicle ON/OFF state

• US 10,347,056 B2
• Filed: 04/17/2017
• Issued: 07/09/2019
• Est. Priority Date: 04/17/2017
• Status: Active Grant

• Current Assignee: Phillips Connect Technologies, LLC
• Original Assignee: Connected Holdings, LLC (Phillips Connect Technologies, LLC)
• Inventors: Winograd, Gil
• Primary Examiner(s): Shaawat, Mussa A
• Application Number:
  US15/488,718
• Publication Number:
  US 20180300967A1
• Time in Patent Office: 813 Days
• CPC Class Codes: G01S 19/13 Receivers
• CPC Class Codes: G01S 19/42 Determining position
• CPC Class Codes: G01S 5/0027 of actual mobile position, i.e. position determined on mobile
• CPC Class Codes: G07C 5/006 Indicating maintenance
• CPC Class Codes: G07C 5/008 communicating information to a remotely located station transmission systems for measured values G08C
• CPC Class Codes: G07C 5/02 Registering or indicating driving, working, idle, or waiting time only apparatus forming part of taximeters G07B13/00
• CPC Class Codes: H04W 4/48 for in-vehicle communication
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The presence of a powered CAN bus is a good indicator of whether an aftermarket telematics device powered by a vehicle OBD port should enter a low-power mode to prevent unwanted battery drain, as the vehicle will remove power from the CAN bus when it determines the vehicle is not in use. Circuitry in the telematics device monitors the voltage on the CAN bus wires of the OBD port to determine whether the CAN voltage is above or below some threshold, such as 1V. This enables the vehicle ON/OFF status to be determined reliably without any additional wiring in the vehicle. The circuitry may include a simple, inexpensive, and low-power integrated circuit comparator, an operational amplifier, or an ADC to determine whether the vehicle is ON or OFF based on the CAN voltage. A very simple embodiment uses a single MOSFET and resistor to detect the vehicle ON/OFF state.

Claims

1. An apparatus that is operable to electrically connect to a vehicle diagnostic port of a vehicle to receive electrical power therefrom for powering one or more functional components of the apparatus, the apparatus comprising:

a detector circuit for receiving a Controller Area Network (CAN) signal from the vehicle diagnostic port, comparing the CAN signal to a reference voltage, and generating a detector output signal based on comparison of the CAN signal to the reference voltage; and

a power controller that receives a power voltage from the vehicle diagnostic port and receives the detector output signal from the detector circuit, the power controller for providing the power voltage to or removing the power voltage from the one or more functional components of the apparatus based on the detector output signal.

2. The apparatus of claim 1 wherein the power controller generates one or more power control signals based on the detector output signal.

3. The apparatus of claim 1 wherein the detector circuit comprises a comparator that receives the CAN signal on a first comparator input, receives a threshold voltage on a second comparator input, and generates the detector output signal based on whether the voltage amplitude of the CAN signal is greater than the threshold voltage.

4. The apparatus of claim 1 wherein:

the detector circuit comprises an analog-to-digital converter that generates the detector output signal as a digital version of the CAN signal; and

the power controller generates the one or more power control signals based on whether the digital version of the CAN signal is greater in amplitude than a digital version of a threshold voltage.

5. The apparatus of claim 1 wherein the detector circuit comprises a CAN transceiver that generates the detector output signal as indicating whether or not the Controller Area Network is operational.

6. The apparatus of claim 1 wherein the detector circuit comprises an NFET device having a gate connected to the CAN signal, a drain connected to a supply voltage through a first resistor, and a source connected to ground, wherein a voltage level at the drain depends on the voltage amplitude of the CAN signal at the gate, and wherein the voltage level at the drain comprises the detector output signal.

7. The apparatus of claim 1 wherein the detector circuit comprises:

an NFET device having a gate connected to the CAN signal, a drain connected to a supply voltage through a first resistor, and a source connected to ground, wherein a voltage level at the drain depends on the voltage amplitude of the CAN signal at the gate; and

a microcontroller having a General Purpose Input/Output (GPIO) input connected to the drain of the NFET device, the microcontroller for generating the detector output signal based on the voltage level at the drain.

8. The apparatus of claim 1 wherein the detector circuit comprises a microcontroller having a General Purpose Input/Output (GPIO) input connected to the CAN signal, the microcontroller for generating the detector output signal based on a voltage level at the GPIO input.

9. The apparatus of claim 1 comprising a telematics device.

10. An apparatus that is operable to electrically connect to a vehicle diagnostic port of a vehicle to receive electrical power therefrom for powering one or more functional components of the apparatus, the apparatus comprising:

a detector circuit for receiving a Controller Area Network (CAN) signal from the vehicle diagnostic port;

a power controller for controlling the electrical power drawn from the vehicle diagnostic port by the one or more functional components of the apparatus based on the CAN signal.

11. The apparatus of claim 10 wherein the detector circuit comprises a comparator that receives the CAN signal on a first comparator input, receives a threshold voltage on a second comparator input, and generates a detector output signal based on whether the voltage amplitude of the CAN signal is greater than the threshold voltage.

12. The apparatus of claim 10 wherein:

the detector circuit comprises an analog-to-digital converter that generates a detector output signal as a digital version of the CAN signal; and

the power controller controls the electrical power drawn from the vehicle diagnostic port by the one or more functional components based on whether the digital version of the CAN signal is greater in amplitude than a digital version of a threshold voltage.

13. The apparatus of claim 10 wherein the detector circuit comprises a CAN transceiver that generates a detector output signal as indicating whether or not the Controller Area Network is operational.

14. The apparatus of claim 10 wherein the detector circuit comprises an NFET device having a gate connected to the CAN signal, a drain connected to a supply voltage through a first resistor, and a source connected to ground, wherein a voltage level at the drain depends on the voltage amplitude of the CAN signal at the gate, and wherein the voltage level at the drain comprises a detector output signal.

15. The apparatus of claim 10 wherein the detector circuit comprises:

an NFET device having a gate connected to the CAN signal, a drain connected to a supply voltage through a first resistor, and a source connected to ground, wherein a voltage level at the drain depends on the voltage amplitude of the CAN signal at the gate; and

a microcontroller having a General Purpose Input/Output (GPIO) input connected to the drain of the NFET device, the microcontroller for generating a detector output signal based on the voltage level at the drain.

16. The apparatus of claim 10 wherein the detector circuit comprises a microcontroller having a General Purpose Input/Output (GPIO) input connected to the CAN signal, the microcontroller for generating a detector output signal based on a voltage level at the GPIO input.

17. The apparatus of claim 10 comprising a telematics device.

18. A telematics device that is operable to electrically connect to a vehicle diagnostic port of a vehicle to receive electrical power therefrom, the telematics device comprising:

a detector circuit for receiving a Controller Area Network (CAN) signal from the vehicle diagnostic port and generating a detector output signal based on a voltage amplitude of the CAN signal;

one or more functional components that perform functions of the telematics device when provided with electrical power; and

power control means for receiving the electrical power from the vehicle diagnostic port, receiving the detector output signal from the detector circuit, and controlling the electrical power consumed by the one or more functional components based on the detector output signal.

19. The apparatus of claim 18 wherein the one or more functional components comprise one or more of a GPS module, a motion sensor, and a wireless data transceiver.

20. A method for controlling power to one or more functional components of an apparatus that receives power from a vehicle diagnostic port of a vehicle, the method comprising:

(a) monitoring a Controller Area Network (CAN) signal from the vehicle diagnostic port;

(b) comparing a voltage amplitude of the CAN signal to a threshold voltage, wherein the voltage amplitude of the CAN signal comprises an analog voltage value or digital voltage value;

(c) if the voltage amplitude of the CAN signal is greater than the threshold voltage, providing power or increasing power to the one or more functional components; and

(d) if the voltage amplitude of the CAN signal is less than the threshold voltage, removing power or reducing power to the one or more functional components.

21. The method of claim 20 wherein the apparatus comprises a telematics device.