Security system using LADAR-based sensors

• US 8,294,881 B2
• Filed: 08/26/2008
• Issued: 10/23/2012
• Est. Priority Date: 08/26/2008
• Status: Expired due to Fees

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Hellickson, Dean R., Holmquist, Kurt, Cook, James, Guyette, Andrew W., Burns, Robert
• Primary Examiner(s): RATCLIFFE, LUKE D
• Application Number:
  US12/198,678
• Publication Number:
  US 20100053330A1
• Time in Patent Office: 1,519 Days
• Field of Search: 356 301- 285
• US Class Current: 356/5.01
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 19/13 Receivers
• CPC Class Codes: G01S 7/4802 using analysis of echo signal for target characterisation; Target signature; Target cross-section
• CPC Class Codes: G08B 13/181 using active radiation detection systems
• CPC Class Codes: G08B 13/19645 Multiple cameras, each having view on one of a plurality of scenes, e.g. multiple cameras for multi-room surveillance or for tracking an object by view hand-over

Abstract

A security sensor system comprises one or more laser detection and ranging (LADAR) sensors configured for accumulation of three-dimensional image data. In one embodiment, the one or more LADAR sensors each comprise a LADAR device, such as a MEMS device, configured to transmit a plurality of laser pulses, and a microprocessor operatively coupled to the LADAR device. One or more data storage devices is operatively coupled to the microprocessor and configured to store the three-dimensional image data, as well as predetermined protected area boundary and fixed object definitions. A GPS receiver can be operatively coupled to the microprocessor and a GPS antenna. The microprocessor is configured to perform a LADAR image analysis that compares the three-dimensional image data with the protected area boundary and fixed object definitions to identify one or more potential intruders.

Claims

1. A security sensor, comprising:

at least one laser detection and ranging (LADAR) device configured for accumulation of three-dimensional image data by transmitting a plurality of laser pulses;

a data processor in operative communication with the LADAR device and comprising;

a plurality of quantizers configured to each respectively receive elevation values, azimuth values, or range values, based on a laser pulse transmission direction, and generate discrete coordinate values for the LADAR device;

an address converter configured to convert the discrete coordinate values from the quantizers into single address values;

a processing element selector configured to receive the single address values from the address converter, and to receive returned signal strength values from the LADAR device; and

a plurality of processing elements each corresponding to a discrete address value and in operative communication with the processing element selector;

wherein the processing element selector is configured to direct a returned signal strength value to a selected one of the plurality of processing elements such that the selected processing element is associated with a volume of space represented by the discrete coordinate values.

2. The sensor of claim 1, wherein the LADAR device comprises a micro-electro-mechanical systems (MEMS) LADAR device.

3. The sensor of claim 1, further comprising a Global Positioning System (GPS) receiver operatively coupled to the data processor and a GPS antenna.

4. A security system, comprising:

a plurality of security sensors positioned in a secured area, the security sensors comprising;

a plurality of laser detection and ranging (LADAR) devices configured to scan portions of the secured area and to each generate a set of LADAR coordinates comprising an elevation value, an azimuth value, and a range value that are based on a laser pulse transmission direction;

a three-dimensional coordinate transform component for each of the LADAR devices, configured to receive the set of LADAR coordinates from the LADAR device, and convert the LADAR coordinates into a set of earth-based coordinates;

a plurality of quantizers configured to receive the earth-based coordinates from the three-dimensional coordinate transform component, and generate a set of quantized coordinates;

a plurality of address converters each of which is configured to receive the quantized coordinates from the quantizers associated with one of the LADAR devices and to convert the quantized coordinates into a single address value; and

a plurality of processing element selectors each of which is configured to receive the single address value from the address converter and a returned signal strength value from one of the LADAR devices;

wherein the processing element selectors in each of the sensors are configured to direct a returned signal strength value from a respective LADAR device to one of a plurality of processing elements based on the single address value, such that a selected processing element is associated with a volume of space represented by the quantized coordinates of the respective LADAR device.

5. The system of claim 4, wherein the LADAR devices comprise micro-electro-mechanical systems (MEMS) LADAR devices.

6. The system of claim 4, wherein each of the processing elements is configured to receive a returned signal strength value from each LADAR device for a transmitted pulse reflected by a target in the associated volume of space.

7. The system of claim 4, wherein each of the processing elements comprises program code configured to:

apply a scaling factor to one or more returned signal strength values to produce one or more scaled inputs;

combine the scaled inputs to produce a total scaled input reflected signal level;

process the scaled input reflected signal level in a low pass filter to obtain an average total reflected signal level for the volume over time;

compare the average total reflected signal level against a reference signal level to obtain a reflected signal level error;

obtain an absolute value of the reflected signal level error;

compare the absolute value to a threshold value; and

if the threshold value is exceeded, activate an alarm signal.

8. The system of claim 4, wherein the three-dimensional coordinate transform component is configured to receive a location and orientation of the LADAR device expressed in earth-based coordinates.

9. The system of claim 4, wherein the security sensors are positioned such that each LADAR device has a scanning zone that overlaps with the scanning zone of one or more of the other LADAR devices.

10. The system of claim 4, wherein the address converter is configured to receive predetermined excluded locations in the secured area.

11. The system of claim 4, wherein each LADAR device is configured to detect a scattered energy signal strength from a laser pulse transmitted by one or more other LADAR devices.

12. The system of claim 4, further comprising a plurality of discrete LADAR detectors positioned in the secured area and configured to detect scattered energy from a laser pulse transmitted by one or more LADAR devices.