Methods and systems for tracking objects or people within a desired area

• US 9,007,264 B2
• Filed: 02/29/2008
• Issued: 04/14/2015
• Est. Priority Date: 02/29/2008
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH, Robert Bosch LLC (Robert Bosch GmbH)
• Original Assignee: Robert Bosch GmbH
• Inventors: Riley, Jim, Markham, Steve, Marriam, Michael
• Primary Examiner(s): McGue, Frank J
• Application Number:
  US12/040,323
• Publication Number:
  US 20090221301A1
• Time in Patent Office: 2,601 Days
• Field of Search: 342/458
• US Class Current: 342/458
• CPC Class Codes: G01S 11/02 using radio waves G01S19/00 takes precedence
• CPC Class Codes: G01S 5/0231 Emergency, distress or locator beacons
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: G08B 13/1427 with transmitter-receiver for distance detection
• CPC Class Codes: G08B 21/023 Power management, e.g. system sleep and wake up provisions
• CPC Class Codes: G08B 21/0236 Threshold setting
• CPC Class Codes: G08B 21/0247 System arrangements wherein the alarm criteria uses signal strength
• CPC Class Codes: G08B 21/0261 System arrangements wherein the object is to detect trespassing over a fixed physical boundary, e.g. the end of a garden

Abstract

A method for tracking the object includes providing a motion detector on a first radio frequency device and detecting the motion of the first radio frequency device, transmitting radio frequency location signals from the first radio frequency device to a second radio frequency device with time intervals between the transmissions, decreasing the time intervals between the transmissions from the first radio frequency device to the second radio frequency device in response to the detection of motion by the motion detector, and periodically determining a separation distance between the first radio frequency device and the second radio frequency device based on the radio frequency location signals transmitted from the first radio frequency device to the second radio frequency device.

Claims

1. A security system for tracking a location of at least one object within an area defined by a boundary, the security system comprising:

at least one first radio frequency device, each said first radio frequency device being coupled to a corresponding one said object, said at least one first radio frequency device adapted to periodically transmit radio frequency location signals, said at least one first radio frequency device including a boundary calibration switch, said boundary calibration switch being configured to initiate transmission of at least one boundary calibration signal from said at least one first radio frequency device;

a second radio frequency device discrete from said first radio frequency device and configured to receive said radio frequency location signals;

at least one motion detector coupled with said at least one first radio frequency device, said at least one motion detector configured to detect when the at least one first radio frequency device is in motion, wherein said at least one first radio frequency device is configured to periodically transmit said radio frequency location signals at a first rate while said at least one first radio frequency device is not in motion, and wherein said at least one first radio frequency device is configured to periodically transmit said radio frequency location signals at a second rate in response to said motion detector detecting movement of said at least one first radio frequency device, said second rate being greater than said first rate; and

a processor communicatively coupled with said second radio frequency device, said processor being adapted to process said at least one boundary calibration signal and store data relating to said at least one boundary calibration signal, said processor being adapted to compare the data relating to said at least one boundary calibration signal to separation distance data related to said radio frequency location signals.

2. The security system of claim 1 wherein said second radio frequency device includes a processor, said processor being adapted to periodically calculate a separation distance between the first radio frequency device and the second radio frequency device based on the strengths of the radio frequency location signals.

3. The security system of claim 2 further including an alarm communicatively coupled with said processor, said alarm adapted to provide an alarm signal in response to said separation distance being greater than a boundary distance, said boundary distance being a distance between said second radio frequency device and a point on the boundary.

4. The security system of claim 2 wherein said motion detector initiates transmission of a wake up signal in response to said motion detector detecting motion of said at least one first radio frequency device, wherein said second radio frequency device includes a wake up switch, said wake up switch being triggered in response to said wake up signal being received, and wherein, in response to said wake up switch being triggered, said processor is configured to periodically calculate said separation distance at a greater periodic rate relative to when said wake up switch is not triggered.

5. The security system of claim 1 wherein said at least one first radio frequency device includes a plurality of first radio frequency devices.

6. A security system for tracking a location of an object within an area defined by a boundary, the security system comprising:

a first radio frequency device adapted to be coupled to the object and to periodically transmit radio frequency location signals, said at least one first radio frequency device including a manually actuatable boundary calibration switch, said boundary calibration switch being configured to initiate transmission of at least one boundary calibration signal from said at least one first radio frequency device in response to being manually actuated;

a second radio frequency device discrete from said first radio frequency device and configured to receive said radio frequency location signals, said second radio frequency device being adapted to periodically calculate a separation distance between the first radio frequency device and the second radio device based on strengths of the radio frequency location signals; and

a motion detector coupled with said first radio frequency device, said motion detector configured to detect when said first radio frequency device is in motion, said motion detector configured to initiate a wake up signal in response to said motion detector detecting motion of said first radio frequency device,

wherein said second radio frequency device is configured to receive said wake up signal and wherein, in response to said second radio frequency device receiving said wake up signal, said second radio frequency device is configured to periodically calculate said separation distance at a greater periodic rate relative to a time before said second radio frequency device receives said wake up signal; and

a processor communicatively coupled to said second radio frequency device, said processor being adapted to process said at least one boundary calibration signal and store data relating to said at least one boundary calibration signal, said processor being adapted to compare the data relating to said at least one boundary calibration signal to location data relating to said radio frequency location signals.

7. The security system of claim 6 wherein the first radio frequency device periodically transmits said radio frequency location signals at a first rate when said first radio frequency device is not in motion, and wherein the first radio frequency device periodically transmits said radio frequency location signals at a second rate in response to said motion detector detecting movement of said first radio frequency, said second rate being greater than said first rate.

8. The security system of claim 6 further including an alarm adapted to provide an alarm signal when said separation distance is greater than a preset value.

9. The security system of claim 6 wherein said at least one first radio frequency device includes a plurality of first radio frequency devices, the first radio frequency devices being adapted to transmit the radio frequency location signals in sequence such that the radio frequency location signals from the first radio frequency devices are staggered in time relative to each other and such that none of the radio frequency location signals overlap each other in time.