The rate at which something vibrates as a result of an input force is known as the frequency response. This response can be illustrated by a tank of water with a bob floating on the surface. Assume the tank is supported by a table, which can be vibrated at a specific rate. When the table is vibrated, waves appear on the surface of the water in the tank. The bob moves up and down as each wave passes under it. Using the bob to measure the wave from crest to crest, the frequency response of the tank with respect to the table vibration can be determined. Adding weights or changing the water in the tank to another type of fluid will change the frequency at which the tank vibrates.
This innovation works on the same principle as it measures the frequency response of a vehicle to determine if the vehicle is concealing contraband. The vibrations created by the vehicle’s engine while it is running provide the input force, and lasers are used to measure the frequency response. This response is compared to a sample library, and a margin for error is applied. If the measurement of the frequency response falls outside allowable margins, the system will flag the vehicle for further inspection. This invention may find utility at security checkpoints for vehicle inspection, contraband and explosives detection, and for remote cargo scanning.
- Remote sensing of vehicle’s contents without invasive search methods
- US patent 8,482,408 available for license
- Potential for collaboration with Navy researchers