Distance measurement for building automation devices with wireless data communications

• US 7,623,413 B2
• Filed: 12/06/2006
• Issued: 11/24/2009
• Est. Priority Date: 09/09/2004
• Status: Active Grant

• Current Assignee: Siemens Industry Incorporated (Siemens AG)
• Original Assignee: Siemens Industry Incorporated (Siemens AG)
• Inventors: McFarland, Norman R.
• Primary Examiner(s): Lobo; Ian J
• Application Number:
  US11/567,255
• Publication Number:
  US 20070162185A1
• Time in Patent Office: 1,084 Days
• Field of Search: 367/124, 367/127
• US Class Current: 367/127
• CPC Class Codes: G01S 5/0289 of multiple transceivers, e.g. in ad hoc networks
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: G01S 5/30 Determining absolute distances from a plurality of spaced points of known location

Abstract

In a building environment, a distance associated with a building automation device is determined as a function of an interval or an inserted time delay between a wireless transmission of a signal and wireless reception of another signal. For example, a two-way communication is provided with an automatic interval or a desired time delay inserted before responding to a received transmission. By using two-way transmissions, the building automation devices may be free of clock synchronization. Acoustic signals may be used in a building environment to determine a distance. The building automation device may also use radio frequency information for communicating with other devices.

Claims

1. A system for determining a distance for building automation components, the system comprising:

a first building automation device having a first wireless transmitter, a first wireless receiver and a first processor;

a second building automation device having a second wireless transmitter, a second wireless receiver and a second processor;

wherein the first wireless transmitter is operable to transmit a first signal, the second wireless receiver is operable to receive the first signal, the second wireless transmitter is operable to transmit a second signal in response to detection of a first zero point crossing within the first signal and after an interval, the first wireless receiver operable to receive the second signal and detect a second zero point crossing within the second signal, and the first processor, second processor or a third processor operable to determine a distance between the first and second building automation devices as a function of the time between the detection of the first zero point crossing within the first signal and the detection of the second zero point crossing within the second signal.

2. The system of claim 1 wherein the second wireless transmitter is operable to transmit the second signal after the interval associated with an immediate response.

3. The system of claim 2 wherein the interval associated with the immediate response is set by a communications protocol.

4. The system of claim 1 wherein the second building automation device is operable to count clock cycles from reception of the first signal, the interval corresponding to the count.

5. The system of claim 1 wherein the second building automation device is operable to set a count-down time from reception of the first signal, the interval corresponding to the count-down time.

6. The system of claim 1 wherein the first processor is operable to determine the distance.

7. The system of claim 1 wherein the first and second building automation devices are operable to identify a data marker in a data stream of the second and first signals, respectively;

wherein the distance is a function of timing of the identification.

8. The system of claim 7 wherein the data marker comprises a frame marker.

9. The system of claim 7 wherein the data marker comprises a marker placed in every frame pursuant to a protocol.

10. The system of claim 1 wherein the first and second transmitters comprise speakers and the first and second receivers comprise microphones.

11. The system of claim 1 wherein the first transmitter and first receiver comprise a first radio frequency transceiver, and the second transmitter and second receiver comprises a second radio frequency transceiver.