Networked sensor system

• US 6,002,996 A
• Filed: 11/26/1997
• Issued: 12/14/1999
• Est. Priority Date: 11/26/1997
• Status: Expired due to Fees

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Fort, Dennis E., Burks, Gregory L., Widmer, Hans P., Spencer, Erika L. S.
• Primary Examiner(s): ASSOUAD, PATRICK J
• Application Number:
  US08/979,266
• Time in Patent Office: 748 Days
• Field of Search: 702/188, 364/130, 364/138, 364/140.02, 364/468.15, 340/870.01, 395/200.31, 395/200.47, 395/200.53, 395/200.83, 395/821, 395/828, 395/835, 395/882, 395/280, 395/284, 395/200.87, 395/200.81, 395/200.5, 370/280, 370/306, 370/309, 710/8, 709/217, 709/220
• US Class Current: 702/188
• CPC Class Codes: H04J 2203/0042 Ring
• CPC Class Codes: H04J 2203/006 Fault tolerance and recovery
• CPC Class Codes: H04J 3/085 for ring networks, e.g. SDH/SONET rings, self-healing rings, meashed SDH/SONET networks
• CPC Class Codes: H04L 41/0806 for initial configuration or provisioning, e.g. plug-and-play
• CPC Class Codes: H04L 41/0893 Assignment of logical groups to network elements
• CPC Class Codes: H04L 7/0008 Synchronisation information channels, e.g. clock distribution lines

Abstract

A networked sensor system that simultaneously acquires, processes, and transmits sensor data under the control of a central processing unit. The system includes sensors connected to sensor processing modules. The sensor processing modules are serially coupled together and to the central processing unit by a fiber optic network. The central processing unit can change the sensor sampling rate by changing a global clock rate, can describe the number and layout of sensor processing modules and their associated sensors allowing for reconfiguration in accordance with a desired application, and can download code to the sensor processing modules for modifying processing functions for a given application. The global clock also allows for synchronous sampling throughout the network. Sensor gain in the sensor processing modules is dynamically programmed by the central processing unit.

Claims

1. A networked sensor system for continuous, high speed, real time, data acquisition, said system comprising:

central processing means;

distributed sensor processing means, coupled to said central processing means, for serially passing data over a first fiber optic cable and a global clock signal over a second fiber optic cable in opposite directions between respective sensor processing means and said central processing means, said global clock signal synchronizing all said sensor processing means for simultaneous data acquisition;

sensors attached to said sensor processing means; and

a power supply, connected to said sensor processing means, for supplying power to said sensor processing means.

2. A networked sensor system according to claim 1, wherein said central processing means has configuration files stored therein and wherein said networked sensor system dynamically defines the number of said sensors, sensor processing means, and their respective locations via one of said configuration files, allowing all sensor processing means to be interchangeable and configurable on demand.

3. A networked sensor system according to claim 2, wherein said sensor processing means includes:

a low noise signal conditioning unit, operatively connected to said sensors, for amplifying low level signals from said sensors and providing a buffered output;

an analog-to-digital converter, operatively connected to said low noise signal conditioning unit, for sampling the output from said low noise signal conditioning unit;

a processor, operatively connected to said central processing means, for processing data according to programs stored in said central processing means; and

fiber optic communication means, serially connecting said sensor processing means, for passing said data packets and said global clock.

4. A networked sensor system according to claim 3, wherein said low noise signal conditioning unit is controlled by said central processing means.

5. A networked sensor system according to claim 4, wherein said analog-to-digital converter samples at a programmable rate determined by said global clock signal.

6. A networked sensor system according to claim 4, wherein said central processing means generates and selects a sampling rate of said global clock.

7. A networked sensor system according to claim 4, wherein said sensor processing means perform narrowband and broadband Fast Fourier Transforms (FFTs) on the data.

8. A networked sensor system according to claim 7, wherein the data is processed according to a program in a nonvolatile memory in said sensor processing means.

9. A method for providing a networked sensor system, said method comprising the steps of:

a) collecting data at specified locations using sensors;

b) sensor processors receiving data from respective sensors and receiving data packets from respective sensor processors;

c) passing data and data packets from the sensor processors and a global clock signal between serially connected sensor processors over fiber optic cable; and

d) operating on the received data packets according to instructions from a central processing unit, the central processing unit having configuration files stored therein;

e) dynamically defining the number of sensors and sensor processors and their location according to one of the configuration files on the central processing unit; and

f) allowing all sensor processors to be interchangeable and configurable on demand.

10. A method according to claim 9, further comprising the steps of:

g) performing functions, determined by software, on the data; and

h) forming coherent sums of data from any of the sensors on the fiber optic network.

11. A method according to claim 10, wherein in said step g) the functions are easily modified by downloading code from the central processing unit.

12. A method according to claim 11, wherein said step g) further includes performing narrowband and broadband Fast Fourier Transforms (FFTs) on the data.

13. A method according to claim 10, further comprising the step of switching, within seconds, programs running on any and all sensor processors.

14. A method according to claim 10, further comprising the step of sampling an output from a programmable low noise signal conditioning unit by an analog-to-digital converter.

15. A method according to claim 13, wherein said sampling step includes sampling the output at a programmable rate determined by the global clock.

16. A method according to claim 14, further comprising the step of switching programs, by the central processing unit, on any and all sensor processing modules using a command over the fiber optic network.

17. A method according to claim 15, further comprising the step of dynamically controlling which sensors contribute data over the fiber optic network.

18. A networked sensor system for continuous, high speed, real time, data acquisition, said system comprising:

sensor processing modules passing data and a global clock, the global clock synchronizing all the sensor processing modules for simultaneous data acquisition;

fiber optic cables serially connecting said sensor processing modules together, for passing the data and the global clock;

sensors, connected to said sensor processing modules, for sensing data input to said sensor processing modules; and

a central processing unit, operatively connected to said sensor processing modules, for commanding said sensor processing modules.

19. A networked sensor system providing continuous, high speed, real time, data acquisition, said system comprising:

a fiber optic network;

a network of distributed sensor processing modules for serially passing data on a first fiber optic cable and a global clock signal on a second fiber optic cable, said global clock signal synchronizing all sensor processing modules in said network of distributed sensor processing modules;

sensors, coupled to each of said sensor processing modules, for obtaining data to be processed; and

a central processor, coupled to said network of distributed sensor processing modules, switching programs running on said sensor processing modules on demand via a command over said fiber optic network and dynamically controlling which sensors contribute data over said fiber optic network.

20. A networked sensor system according to claim 19, wherein sensor processing modules in said network of sensor processing modules simultaneously sample data with said global clock signal.

21. A networked sensor system according to claim 20, wherein each of said distributed sensor processing modules inserts data into data packets and forwards said data packets simultaneously with said data from said sensors.