Distance measurement for building automation devices with wireless data communications

• US 8,036,064 B2
• Filed: 01/20/2009
• Issued: 10/11/2011
• 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
• Application Number:
  US12/356,239
• Publication Number:
  US 20100182875A1
• Time in Patent Office: 994 Days
• Field of Search: 367/124, 367/127, 342/118, 342/125
• 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 method for determining a distance for a building automation device, the method comprising:

(a) wirelessly transmitting a first signal from the building automation device within a building;

(b) wirelessly receiving a second signal at the building automation device within the building, wherein the first and second signals are communicated according to a wireless mesh networking communication protocol; and

(c) identifying a data marker in a data stream of the first signal, second signal, or first and second signals; and

(d) determining a distance associated with the building automation device as a function of a time-of-flight for the identified data marker and a known time delay interval.

2. The method of claim 1 wherein (b) is performed after (a), and wherein a remote building automation device within the building responds to the first signal after the delay interval, the response being the second signal.

3. The method of claim 1 wherein the known time delay interval comprises an immediate response time.

4. The method of claim 3 wherein the immediate response time is set by the wireless mesh networking communications protocol.

5. The method of claim 1 wherein the known time delay interval comprises a clock cycle count.

6. The method of claim 1 wherein the known time delay interval comprises a timer countdown.

7. The method of claim 1 wherein (a) is performed after (b), and wherein the building automation device delays sending the first signal by the known time delay interval after receiving the second signal.

8. The method of claim 1 wherein (d) comprises determining the distance with a processor of the building automation device.

9. The method of claim 1 wherein the data marker is a frame marker.

10. The method of claim 9 wherein the frame marker is placed in every frame pursuant to the wireless mesh networking communication protocol.

11. The method of claim 1 wherein the mesh networking communication protocol is a ZIGBEE protocol.

12. The method of claim 1 wherein the mesh networking communication protocol is an IEEE 802 communication protocol.