INTELLIGENT NETWORK SENSOR SYSTEM

• US 20160254844A1
• Filed: 02/27/2015
• Published: 09/01/2016
• Est. Priority Date: 02/27/2015
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Binnamangalam, Harsha, Hull, Jonathan J., Gudan, Ken
• Granted Patent: US 10,158,401 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 5/77 for interrogation
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: H04W 52/0296 switching to a backup power supply
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A network sensor system and method for using the same are disclosed herein. In one embodiment, the network sensor system comprises: a radio-frequency (RF) emitter; a first sensor tag including a transmitter, an energy harvesting unit operable to convert incident RF energy to direct current (DC) including RF energy from the RF emitter and RF energy from one or more ambient sources, a storage unit operable to store recovered DC power, one or more sensors for sensing and logging data, a controller coupled to the energy harvesting and storage units, the one or more sensors and the transmitter, to communicate data in the form of a Bluetooth Low Energy (BLE) advertising packet using energy previously harvested and stored by the energy harvesting and storage unit; and a first device to receive the BLE advertising packet.

Claims

1. A network sensor system comprising:

a radio-frequency (RF) emitter;

a first sensor tag including

a transmitter,

an energy harvesting unit operable to convert incident RF energy to direct current (DC) including RF energy from the RF emitter and RF energy from one or more ambient sources,

a storage unit operable to store recovered DC power,

one or more sensors for sensing and logging data,

a controller coupled to the energy harvesting and storage units, the one or more sensors and the transmitter, to communicate data in the form of a Bluetooth Low Energy (BLE) advertising packet using energy previously harvested and stored by the energy harvesting and storage unit; and

a first device to receive the BLE advertising packet.

2. The system defined in claim 1 wherein the RF emitter is operable to perform a sweep algorithm in which the RF emitter transmits RF energy at a plurality of frequencies to enable determination of which frequency among the plurality of frequencies provides a best power transfer efficiency (PTE) for the tag.

3. The system defined in claim 2 wherein the tag is operable to determine the charge energy for each of the plurality of frequencies and identifies one of the plurality of frequencies as the one frequency that produced more charge energy that any other of frequencies of the plurality of frequencies.

4. The system defined in claim 3 wherein the PTE for the tag is based on the charge energy at the one frequency and the received signal strength of a BLE packet from the tag.

5. The system defined in claim 2 wherein the device is operable to transmit a wakeup indication to the tag at a time associated with a start of the sweep algorithm to enable the tag to synchronize with the RF emitter when the RF emitter performs the sweep algorithm.

6. The system defined in claim 2 wherein the device is operable to:

determine whether the tag is to perform a transmit operation based on charge rate of the tag, an amount of energy necessary for the tag to complete the transmit operation, and an amount of time necessary for the tag to complete the transmit operation; and

cause a message to be transmitted to the tag based on results of determining whether the tag is to perform the operation.

7. The system defined in claim 1 wherein the tag includes first, second and third modes of operation, wherein

in the first mode, in response to a first pulse, the tag transmits identification information,

in the second mode, in response to a second pulse, the tag receives a notification that the tag is to provide information to the device without having to turn on its receiver, and

in the third mode, in response to a third pulse, the tag receives a notification that the tag is to provide information to the device and turn on its receiver.

8. The system defined in claim 1 wherein the BLE advertising packet contains ID information.

9. The system defined in claim 1 wherein the BLE advertising packet contains one or more sensor readings from the one or more sensors.

10. The system defined in claim 1 wherein the first device comprises a smart phone or an internet gateway.

11. The system defined in claim 1 wherein the first device converts the BLE packet to a message for transmission over the Internet.

12. A sensor tag for use in a sensor system, the tag comprising:

a transmitter;

an energy harvesting unit operable to convert incident RF energy to direct current (DC) including RF energy from a RF emitter and RF energy from one or more ambient sources;

a storage unit operable to store recovered DC power;

one or more sensors for sensing and logging data;

a controller coupled to the energy harvesting and storage units, the one or more sensors and the transmitter, to communicate data from in the form of a Bluetooth Low Energy (BLE) advertising packet using energy previously harvested and stored by the energy harvesting and storage unit,

wherein the tag determines the charge energy for each of a plurality of frequencies transmitted from the RF emitter executing an sweep algorithm and identifies one of the plurality of frequencies as the one frequency that produced more charge energy that any other of frequencies of the plurality of frequencies.

13. The tag defined in claim 12 wherein the tag receives a wakeup indication to synchronize itself with the RF emitter when the RF emitter performs the sweep algorithm.

14. The tag defined in claim 12 wherein the controller controls the tag in first, second and third modes of operation, wherein

in the first mode, in response to a first pulse, the radio transmits identification information,

in the second mode, in response to a second pulse, the radio transmits information without having to turn on its receiver, and

in the third mode, in response to a third pulse, the radio transmits information and turns on its receiver.

15. The tag defined in claim 12 wherein the BLE advertising packet contains ID information.

16. The tag defined in claim 12 wherein the BLE advertising packet contains one or more sensor readings from the one or more sensors.

17. A method for use in a sensor system having a tag, an RF emitter and a device, the method comprising:

performing, by the RF emitter, a sweep algorithm in which the RF emitter transmits RF energy at a plurality of frequencies;

determining, by the tag, charge energy for each of the plurality of frequencies;

identifying, by the tag, one of the plurality of frequencies as the one frequency that produced more charge energy that any other of frequencies of the plurality of frequencies;

determining which frequency among the plurality of frequencies provides a best power transfer efficiency (PTE) for the tag.

18. The method defined in claim 17 wherein the PTE for the tag is based on the charge energy at the one frequency and the received signal strength of a BLE packet from the tag.

19. The method defined in claim 17 further comprising transmitting, by the device, a wakeup indication to the tag at a time associated with a start of the sweep algorithm to enable the tag to synchronize with the RF emitter when the RF emitter performs the sweep algorithm.

20. The method defined in claim 17 further comprising:

determining, by the device, whether the tag is to perform a transmit operation based on charge rate of the tag, an amount of energy necessary for the tag to complete the operation, and an amount of time necessary for the tag to complete the operation; and

sending an indication to the tag based on results of determining whether the tag is to perform the transmit operation.