Fluidic sonar sensor
| Title: | Fluidic sonar sensor |
|---|---|
| Patent Number: | 5,164,919 |
| Publication Date: | November 17, 1992 |
| Appl. No: | 07/802,796 |
| Application Filed: | December 06, 1991 |
| Abstract: | A sonar sensor comprising a substantially non-corrodible housing and a fluidic gainblock disposed therein. In addition, one or more fluid-filled laminar proportional amplifiers are arranged either in series or in parallel and contained within the fluidic gainblock. Means are provided to produce a jet within each laminar proportional amplifier, which is then modulated by incoming acoustic signals. The pressure caused by diverting the jet from its equilibrium path is proportional to, but greater than, the incoming acoustic signal. Hydrophones are used to convert the amplified acoustic signal into an electrical signal. In one embodiment, the fluidic gainblock is free-flooded and open to the liquid environment in which it is used, obviating the need for pressure equalization. In another embodiment, the fluidic gainblock is provided with filtering means for prevent the accumulation of sediment within the cavities making up the laminar proportional amplifiers. In yet another embodiment, the fluidic gainblock is a closed-system which recirculates its fluid supply, increasing the sensor's operating life and isolating the laminar proportional amplifiers therein. |
| Inventors: | Scanlon, Michael (Springfield, VA); Tenney, Stephen M. (Rockville, MD); Srour, Nassy (Silver Spring, MD); Joyce, James W. (Rockville, MD) |
| Assignees: | United States of America as represented by the Secretary of the Army (Washington, DC) |
| Claim: | We claim |
| Claim: | 1. A sensor for detecting acoustic signals in a liquid environment at variable depths, said sensor comprising |
| Claim: | a substantially non-corrodible housing; |
| Claim: | a fluidic gainblock disposed within said housing to amplify said acoustic signal, said fluidic gainblock having at least one laminar proportional amplifier, wherein each laminar proportional amplifier is provided with an input port which is exposed to said acoustic signal, a control port which is maintained at approximately ambient pressure, one or more pairs of venting ports, and two output ports; |
| Claim: | means to create and maintain a liquid jet within each laminar proportional amplifier; |
| Claim: | one or more transducers disposed within said output ports to convert amplified acoustic signals into electrical signals. |
| Claim: | 2. The invention of claim 1 wherein said means to produce a liquid jet comprises one or more plenum ports and towing means. |
| Claim: | 3. The invention of claim 1 wherein said means to produce a liquid jet comprises a pump. |
| Claim: | 4. The invention of claim 1, 2, or 3 further comprising a plurality of cascading laminar proportional amplifiers wherein only the first of said laminar proportional amplifiers is provided with a control port maintained at approximately ambient pressure, and the output ports of said first laminar proportional amplifier feed into the input ports of subsequent laminar proportional amplifiers. |
| Claim: | 5. The invention of claim 1, 2, or 3 wherein said housing is comprised of neoprene rubber. |
| Claim: | 6. The invention of claim 4 wherein said housing is comprised of neoprene rubber. |
| Claim: | 7. The invention of claim 1, 2, or 3 wherein said input port which is exposed to said acoustic signal terminates in a filter. |
| Claim: | 8. The invention of claim 4 wherein said input port which is exposed to said acoustic signal terminates in a filter. |
| Claim: | 9. The invention of claim 5 wherein said input port which is exposed to said acoustic signal terminates in a filter. |
| Claim: | 10. The invention of claim 6 wherein said input port which is exposed to said acoustic signal terminates in a filter. |
| Claim: | 11. A sensor for detecting acoustic signals in a liquid environment at variable depths, said sensor comprising |
| Claim: | a waterproof and substantially non-corrodible housing; |
| Claim: | one or more acoustically transparent membranes disposed upon the outside surface of said housing; |
| Claim: | a fluidic gainblock disposed within said housing to amplify said acoustic signal, said fluidic gainblock having at least one liquid-filled laminar proportional amplifier, wherein each laminar proportional amplifier is provided with an input port in communication with one or more of said transparent membranes, a control port which is maintained at approximately ambient pressure, one or more pairs of venting ports which empty into a reservoir, and two output ports; |
| Claim: | means to recirculate, and regulate the pressure of, said liquid within each laminar proportional amplifier, so that the internal pressure within the control port is substantially the same as the hydrostatic pressure of the liquid environment; |
| Claim: | 12. The invention of claim 11 further comprising a plurality of cascading laminar proportional amplifiers, wherein only the first of said laminar proportional amplifiers is provided with a control port maintained at approximately ambient pressure, and the output ports of said first laminar proportional amplifier vent into the input ports of subsequent laminar proportional amplifiers. |
| Claim: | 13. The invention of either of claims 11 or 12 wherein said housing and membranes are comprised of neoprene rubber. |
| Claim: | 14. A sensor for detecting acoustic signals in a liquid environment at variable depths, said sensor comprising |
| Claim: | a fluidic gainblock having at least one laminar proportional amplifier, wherein each laminar proportional amplifier comprises |
| Claim: | (a) a substantially non-corrodible housing; |
| Claim: | (b) a liquid-filled cavity disposed within said housing and having forward and aft ends; |
| Claim: | (c) means to produce a liquid jet in said cavity which travels from said forward end to said aft end; |
| Claim: | (e) two output ports extending from the aft end of said cavity in such a way as to collect equal portions of said jet in the absence of an acoustic signal; |
| Claim: | (f) one or more pairs of venting ports which extend from said cavity to a reservoir and are disposed forward of said output ports and on opposite sides of said jet; |
| Claim: | (g) an input port which extends from said cavity and is disposed forward of said venting ports and on one side of said jet, wherein said input port is exposed to said acoustic signal; |
| Claim: | (h) a control port which extends from said cavity and is disposed opposite said input port on the other side of said jet; |
| Claim: | (i) means to sense the hydrostatic pressure of the liquid environment; |
| Claim: | (j) means to maintain the control port at or near the same hydrostatic pressure as the liquid environment; |
| Claim: | whereby an acoustic signal travelling in said liquid environment is made to pass through said input port, causing a change in pressure on one side of said jet, thereby inducing the jet to deflect, and a greater portion of the jet to be collected by one of the two output ports, which affects the pressure therein in a manner proportional to the acoustic signal detected; |
| Claim: | one or more transducers in communication with said output ports to convert pressure variations therein into electrical signals. |
| Claim: | 15. The invention of claim 14 wherein said cavity and ports are sealed-off from said liquid environment to form a closed system, and said input port terminates in an acoustically transparent membrane, said membrane being exposed on one side to the liquid environment. |
| Claim: | 16. The invention of claim 15 wherein said membrane is comprised of neoprene rubber. |
| Claim: | 17. The invention of claims 14, 15 or 16 wherein said housing is comprised of neoprene rubber. |
| Claim: | 18. The invention of claims 14, 15 or 16 further comprising a plurality of cascading laminar proportional amplifiers, wherein only the first of said laminar proportional amplifiers is provided with a control port maintained at approximately ambient pressure, and the output ports of said first laminar proportional amplifier feed into the input ports of subsequent laminar proportional amplifiers. |
| Claim: | 19. The invention of claim 17 further comprising a plurality of cascading laminar proportional amplifiers, wherein only the first of said laminar proportional amplifiers is provided with a control port maintained at approximately ambient pressure, and the output ports of said first laminar proportional amplifier feed into the input ports of subsequent laminar proportional amplifiers. |
| Current U.S. Class: | 367/135; 367/178; 367/901 |
| Current International Class: | H04R 1500 |
| Patent References Cited: | 4102075 July 1978 Wagner et al. 4964100 October 1990 Srour et al. 4970704 November 1990 Kelly |
| Other References: | Joyce, J. W., "Design Guide for Fluidic Laminar Proportional Amplifiers and aminar Jet Angular Rate Sensor," Harry Diamond Laboratories, HDL-SR-84-6 (1984). |
| Primary Examiner: | Pihulic, Daniel T. |
| Attorney, Agent or Firm: | Elbaum, Saul Shapiro, Jason M. |
| Accession Number: | edspgr.05164919 |
| Database: | USPTO Patent Grants |
| Language: | English |
|---|