Explosives and contraband detection system

• US 8,482,408 B1
• Filed: 12/08/2008
• Issued: 07/09/2013
• Est. Priority Date: 12/08/2008
• Status: Active Grant

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Cottrell, Dana
• Primary Examiner(s): Zimmerman, Brian
• Assistant Examiner(s): EUSTAQUIO, CAL J
• Application Number:
  US12/329,726
• Publication Number:
  US 20130197864A1
• Time in Patent Office: 1,674 Days
• Field of Search: 340/540, 702/56, 735/97
• US Class Current: 340/540
• CPC Class Codes: G01H 3/00 Measuring characteristics of vibrations by using a detector in a fluid G01H7/00, G01H9/00, G01H11/00 take precedence
• CPC Class Codes: G01H 9/00 Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means

Abstract

A non-invasive system for detection of explosives and contraband in a vehicle includes at least one laser vibrometer for measuring vehicle vibrations at one or more points on the vehicle while the vehicle is operating. One laser vibrometer can be sequentially directed to various points on the vehicle according to a predetermined single point or pattern. Or, a plurality of laser vibrometers could be used to simultaneously illuminate the vehicle. After measurement, the vehicle vibrations are compared to a database of reference vibrations, which that were taken of similar vehicles that were known to be contraband-free. The measured vibrations are compared to the vibrations pattern for the same type of vehicle. If the vibration patterns exhibit differences in frequency peaks that exceed predetermined parameters, the system alerts the operator. A more detailed inspection of the vehicle can then be accomplished.

Claims

1. A system for inspecting operating vehicles at a security checkpoint, said checkpoint having a desired throughput and a threat level, said vehicles having at least one compartment, said system comprising:

at least one means for measuring vehicle vibrations generated by said compartment, said vehicle vibrations being caused the operation of said vehicle, said vehicle vibrations being measured from outside of said vehicle, said vehicle vibrations having a plurality of vehicle frequency spectral peaks and a vehicle low frequency band;

a database of predetermined reference vibrations, said reference vibrations corresponding to said vehicles having said compartments that have not been modified, said reference vibrations being caused by the operation of said vehicles, said reference vibrations having a plurality of reference frequency spectral peaks and a reference low frequency band;

a processor for comparing said vehicle vibrations to said reference vibrations for detecting an anomaly in said non-machinery components, said anomaly being deemed to exist when said vehicle frequency spectral peaks and said reference frequency spectral peaks differ more than a predetermined amount, and when said vehicle low frequency band amplitude is less than said reference low frequency band by a predetermined amount; and

,

said processor adjusting said spectral peak predetermined amount and said frequency band predetermined amount according to said throughput and said threat level.

2. A method for non-invasive inspection of operating vehicles at a security checkpoint, said checkpoint having a desired throughput and a threat level, said vehicles having at least one compartment, said method comprising the steps of:

A) establishing a database of reference vibrations corresponding to said vehicles, said reference vibrations having emanated from the exterior surface of said compartment, said reference vibrations being caused by the operation of said vehicles, said reference vibrations further having a plurality of reference frequency spectral peaks and a reference low frequency band;

corresponding to said compartment that has not been modified;

B) measuring vehicle vibrations corresponding to said vehicles, and further emanating from the exterior surface of said compartment, said vehicle vibrations being caused by the operation of said vehicle, said vehicle vibrations further having a plurality of vehicle frequency spectral peaks and a vehicle low frequency band;

C) comparing said vehicle vibrations to said reference vibrations;

D) deeming said vehicle as having an anomaly in at least one compartment when the results of said step C) indicate that said vehicle low frequency band is less than said reference low frequency band by a predetermined amount, and that said vehicle frequency spectral peaks differ from said reference frequency spectral peaks by a predetermined amount; and

,

D1) adjusting said frequency band predetermined amount and said spectral peak predetermined amount according to said desired throughput and said threat level.

3. The method of claim 2, further comprising the step of:

E) alerting the system operator.