Vehicle telemetric system

• US 20060022842A1
• Filed: 08/02/2004
• Published: 02/02/2006
• Est. Priority Date: 08/02/2004
• Status: Active Grant

• Current Assignee: GeoTab Incorporated
• Original Assignee: Netistix Technologies Corporation (GeoTab Incorporated)
• Inventors: Goodall, Colin David, Zoladek, Jacek Grzegorz, Preece, Douglas John, Pepper, Gary Thomas
• Granted Patent: US 7,123,164 B2
• Time in Patent Office: Days
• US Class Current: 340/870.70
• CPC Class Codes: G07C 5/008 communicating information to a remotely located station transmission systems for measured values G08C

Abstract

A vehicle telemetric system comprises vehicle interface units (VIUs), wireless gateways, and a central host. The VIU in a vehicle collects data over the OBD-II bus and stores the data in the form of Data Point Records (DPRs) in an on-board flash memory. When the VIU is within wireless range of a gateway, it establishes a WiFi (802.11b) connection with the gateway, and submits stored DPRs to the gateway, to be stored in permanent storage at the gateway. The gateways communicate with the central host over a wide area network (WAN). When a gateway has gathered new DPRs from a VIU, it submits these to the central host. Databases in the gateways as well as in the central host are maintained and synchronized to track received DPRs by sequence number and originating VIU. In conjunction with specific protocols, all DPRs are thus collected reliably, even though communication with a vehicle may be intermittent. Efficient use of WiFi bandwidth is made by avoiding the unnecessary collection of duplicate DPRs.

Claims

1. A vehicle telemetric system, comprising:

a central host connected to a communications network;

one or more gateways connected to the communications network, the communications network enabling the transfer of packet data between the gateways and the central host;

a vehicle interface unit (VIU) within a vehicle having access to sensors in the vehicle for collecting vehicle related data, the VIU having means for communication over a wireless link of any of said gateways when the vehicle is within a transmission range of one of said gateways;

the VIU further comprising means for aggregating and formatting the vehicle related data into a data point record (DPR) including a unique sequence number and a vehicle identification number;

the VIU having a memory for storing a list of DPRs, and a VIU means for forwarding the DPRs to the one of said gateways over the wireless link;

each gateway having another memory for storing the DPRs received from the VIU, and a gateway means for forwarding the DPRs to the central host; and

the central host having means for storing DPRs generated by the VIU and received from all gateways, and means for notifying each gateway regarding the sequence numbers and the vehicle identification numbers of the DPRs that have been already received at the central host.

2. A vehicle telemetric system as described in claim 1, wherein the DPR is of a size designed to fit into the payload of a layer 3 (network layer) packet, which in turn fits into a single packet of the wireless layer 2 (data link layer) protocol used for communicating over the wireless link.

3. A vehicle telemetric system as described in claim 2, wherein the wireless link is a short range wireless link.

4. A vehicle telemetric system as described in claim 2, wherein the layer 2 protocol used for communicating over the wireless link is the 802.11b protocol.

5. A vehicle telemetric system as described in claim 2, wherein the layer 3 protocol used for communicating between the VIU and the gateway is the Internet Protocol (IP).

6. A vehicle telemetric system as described in claim 3, wherein the size of each DPR transmitted in accordance with the 802.11b protocol is less than the Ethernet maximum transmission unit.

7. A vehicle telemetric system as described in claim 1, wherein the VIU means for forwarding comprises means for forwarding selected DPRs as instructed by the one of said gateways.

8. A vehicle telemetric system as described in claim 7, wherein the VIU means for forwarding selected DPRs comprises means for forwarding the selected DPRs in reverse order, starting with the most recently aggregated DPR.

9. A vehicle telemetric system as described in claim 1, wherein the means in the VIU for communication over the wireless link comprises announcement means for generating an announcement packet, including the sequence number of the most recent DPR, and a counter identifying how many DPRs are available to be forwarded to the one of said gateways.

10. A vehicle telemetric system as described in claim 9, wherein the announcement means comprises timing means for repeatedly transmitting said announcement packet at a time interval as long as the wireless link is activated.

11. A vehicle telemetric system as described in claim 10, wherein the timing means comprises means for changing the time interval to a longer time interval after a predetermined number of announcement packets have been sent.

12. A vehicle telemetric system as described in claim 1, wherein the DPR includes the following fields:

a header comprising a VIU serial number,

a data length fields indicating the amount of vehicle related data aggregated in the DPR; and

a data field, including a number of data points, each data point including an encoded data and a time offset at which the encoded data was collected from the vehicle.

13. A vehicle telemetric system as described in claim 1, wherein the central host comprises means for identifying gaps in continuity in the sequence numbers of the received DPRs (the missing DPRs) and informing the gateways of the gaps, and the gateways comprise means for requesting the missing DPRs from the VIU when the vehicle is within the respective transmission range.

14. A vehicle telemetric system as described in claim 1, wherein the VIU means for forwarding comprises a means for forwarding a first set of the DPRs to the one of said gateways over the wireless link when the wireless link is activated, and for forwarding a second set of the DPRs to another of said gateways over another wireless link when the another wireless link is activated, so that the first and second sets of DPRs form the complete said list of DPRs.

15. A vehicle interface unit (VIU) for a vehicle telemetric system, comprising a central host connected to a communications network and one or more gateways connected to the communications network, which enables the transfer of packet data between the gateways and the central host, the VIU being located in a vehicle and having access to sensors in the vehicle for collecting vehicle related data, the VIU having means for communication over a wireless link with any of said gateways, the wireless link being activated when the vehicle is within a transmission range of the one of said gateways, and another wireless link being activated when the vehicle is within a transmission range of another one of said gateways;

the VIU further comprising a means for aggregating and formatting the vehicle related data into a list of data point records (DPRs), each DPR including a unique sequence number and a vehicle identification number;

the VIU having a memory for storing the DPRs, and a VIU means for forwarding a first set of the DPRs to the one of said gateways over the wireless link when the wireless link is activated, and for forwarding a second set of the DPRs to said another of said gateways over the another wireless link when the another wireless link is activated, so that the first and second sets of DPRs form the complete said list of DPRs.

16. A VIU as described in claim 15, wherein the DPR is of a size designed to fit into the payload of a layer 3 (network layer) packet, which in turn fits into a single packet of the wireless layer 2 (data link layer) protocol used for communicating over the wireless link.

17. A VIU as described in claim 16 wherein the layer 2 protocol used for communicating over the wireless link is the 802.11b protocol.

18. A VIU as described in claim 16 wherein the layer 3 protocol used for communicating between the VIU and the gateway is the Internet Protocol (IP).

19. An access system for use in a vehicle telemetric system, the telemetric system comprising a central host connected to a communications network, the access system comprising:

one or more vehicle interface units (VIUs) and a gateway, the gateway being connected to the communications network,

each VIU being located in a different vehicle and having access to sensors in the vehicle for collecting vehicle related data, each VIU having means for communication over a wireless link with the gateway, the wireless link being activated when the vehicle is within a transmission range of the gateway;

the VIU further comprising a means for aggregating and formatting the vehicle related data into a data point record (DPR) including a unique sequence number and a vehicle identification number;

each VIU having a memory for storing the DPRs in a list, and a VIU means for forwarding the DPRs to the gateway over the wireless link;

the gateway having another memory for storing the DPRs received from the VIU and a gateway means for forwarding the DPRs to the central host; and

the gateway having means for requesting missing DPRs from each VIU, where the missing DPRs are those that have not been received by the central host.

20. An access system as described in claim 19, wherein the VIU means for forwarding comprises a means for forwarding a first set of the DPRs to the gateway over the wireless link when the wireless link is activated, and for forwarding a second set of the DPRs to the gateway over the wireless link when the wireless link is activated at another time, so that the first and second sets of DPRs form the complete said list of DPRs.

21. A method for monitoring a vehicle'"'"'s performance in a vehicle telemetric system comprising a central host connected to a communications network, one or more gateways connected to the communications network, each gateway having a wireless transmission range, a vehicle interface unit (VIU) within a vehicle having access to sensors in the vehicle for collecting vehicle related data, the VIU having means for wireless communication with any of said gateways, the method comprising the steps of:

(a) in the VIU, collecting, aggregating and formatting the vehicle related data into data point records (DPR), each DPR including a unique sequence number and a vehicle identification number, and storing the DPRs as a list in a VIU memory;

(b) determining if the VIU is within the wireless transmission range of one of the gateways;

(c) forwarding a set of the DPRs from the VIU to the one of said gateways over a wireless link;

(d) forwarding some or all of the set of the DPRs received by the one of said gateways from the one of said gateways to the central host over the communications network; and

(e) notifying each gateway by the central host regarding the sequence numbers and the vehicle identification numbers of the DPRs that have been already received at the central host.

22. A method as described in claim 21, wherein the step (a) comprises formatting the vehicle related data into the DPRs, each DPR being of a size designed to fit into the payload of a layer 3 (network layer) packet, which in turn fits into a single packet of the wireless layer 2 (data link layer) protocol used for communicating over the wireless link.

23. A method as described in claim 21, wherein the step (c) comprises forwarding selected DPRs as instructed by the one of said gateways.

24. A method as described in claim 23, wherein the step of forwarding the selected DPRs comprises forwarding the selected DPRs in reverse order, starting with the most recently aggregated DPR.

25. A method as described in claim 21, further comprising the step of generating an announcement packet by the VIU and sending it to the one of said gateways, the announcement packet including the sequence number of the most recent DPR, and a counter identifying how many DPRs are available to be forwarded to the one of said gateways, the step being performed before the step (c).

26. A method as described in claim 25, wherein the step of generating the announcement packet comprises generating the announcement packet repeatedly at a time interval as long as the wireless link is activated.

27. A method as described in claim 26, wherein the step of generating the announcement packet repeatedly comprises changing the time interval to a longer time interval after a predetermined number of announcement packets have been sent.

28. A method as described in claim 21, wherein the step (e) comprises the step of identifying gaps in continuity in the sequence numbers of the received DPRs (the missing DPRs) and informing the gateways of the gaps, and the step (c) comprises requesting the missing DPRs from the VIU when the vehicle is within the respective transmission range.

29. A method as described in claim 21, wherein the step (c) comprises forwarding a first set of the DPRs to the one of said gateways over the wireless link when the wireless link is activated, and for forwarding a second set of the DPRs to another of said gateways over another wireless link when the another wireless link is activated, so that the first and second sets of DPRs form the complete said list of DPRs.

30. A method as described in claim 21, wherein the step (d) comprises changing the format of the DPRs received by the one of said gateways before the DPRs are forwarded to the central host over the communications network.

31. A method as described in claim 30, wherein the step of changing the format comprises changing the format from a binary representation of the DPR to an ASCII representation.