Tubular sonic displacement sensor

• US 5,629,681 A
• Filed: 05/17/1995
• Issued: 05/13/1997
• Est. Priority Date: 03/01/1993
• Status: Expired due to Fees

• Current Assignee: American Vehicular Sciences LLC (Acacia Research Corporation)
• Original Assignee: Automotive Technologies International Incorporated
• Inventors: Breed, David S., Johnson, Wendell C., DuVall, Wilbur E.
• Primary Examiner(s): Hofsass, Jeffery
• Assistant Examiner(s): Lee, Benjamin C.
• Application Number:
  US08/443,002
• Time in Patent Office: 727 Days
• Field of Search: 340/563, 340/566, 340/565, 340/560, 340/545, 340/550, 340/557, 340/590, 340/621, 340/665, 340/666, 340/436, 340/437, 367/93, 367/94, 367/191, 367/908, 73/591, 73/590, 73/599, 73/290, 320/643
• US Class Current: 340/665
• CPC Class Codes: B60J 10/00 Sealing arrangements
• CPC Class Codes: B60N 2/002 Seats provided with an occupancy detection means mounted therein or thereon detection means responsive to presence or absence of children B60N2/266
• CPC Class Codes: B60N 2/0224 Non-manual adjustments, e.g. with electrical operation
• CPC Class Codes: B60N 2/02246 Electric motors therefor
• CPC Class Codes: B60N 2/0248 with memory of positions
• CPC Class Codes: B60N 2/0268 using sensors or detectors for adapting the seat or seat part, e.g. to the position of an occupant
• CPC Class Codes: B60N 2/0272 using sensors or detectors for detecting the position of seat parts
• CPC Class Codes: B60N 2/0276 reaction to emergency situations, e.g. crash
• CPC Class Codes: B60N 2/28 Seats readily mountable on, and dismountable from, existing seats or other parts of the vehicle
• CPC Class Codes: B60N 2/2806 for securing the child seat to the vehicle
• CPC Class Codes: B60N 2/2863 backward facing
• CPC Class Codes: B60N 2/829 characterised by their adjusting mechanisms, e.g. electric motors
• CPC Class Codes: B60N 2/853 characterised by their adjusting mechanisms, e.g. electric motors
• CPC Class Codes: B60N 2/888 with arrangements for protecting against abnormal g-forces, e.g. by displacement of the head-rest
• CPC Class Codes: B60R 19/483 with obstacle sensors of electric or electronic type
• CPC Class Codes: B60R 2021/0027 Post collision measures, e.g. notifying emergency services
• CPC Class Codes: B60R 2021/01315 monitoring occupant displacement
• CPC Class Codes: B60R 2021/2765 comprising means to control the venting
• CPC Class Codes: B60R 2022/208 by automatic or remote control means
• CPC Class Codes: B60R 21/0134 responsive to imminent contact with an obstacle , e.g. using radar systems
• CPC Class Codes: B60R 21/0136 : responsive to actual contact with an obstacle , e.g. to vehicle deformation, bumper displacement or bumper velocity relative to the vehicle monitoring crash strength in combination with passenger seat detection B60R21/01558
• CPC Class Codes: B60R 21/01516 : using force or pressure sensing means
• CPC Class Codes: B60R 21/01526 : using piezoelectric elements
• CPC Class Codes: B60R 21/01534 : using electromagneticwaves, e.g. infrared
• CPC Class Codes: B60R 21/01536 : using ultrasonic waves
• CPC Class Codes: B60R 21/01538 : for image processing, e.g. cameras or sensor arrays
• CPC Class Codes: B60R 21/01542 : detecting passenger motion
• CPC Class Codes: B60R 21/01552 : detecting position of specific human body parts, e.g. face, eyes or hands
• CPC Class Codes: B60R 21/01554 : Seat position sensors
• CPC Class Codes: B60R 22/20 : adjustable in position, e.g. in height
• CPC Class Codes: B60R 25/25 : using biometry
• CPC Class Codes: E05F 15/43 : responsive to disruption of energy beams, e.g. light or sound
• CPC Class Codes: E05F 2015/433 : using reflection from the obstruction
• CPC Class Codes: E05Y 2400/664 : by radio waves
• CPC Class Codes: E05Y 2900/538 : Interior lids
• CPC Class Codes: E05Y 2900/55 : Windows
• CPC Class Codes: G01F 23/20 : by measurement of weight, e.g. to determine the level of stored liquefied gas
• CPC Class Codes: G01F 23/2962 : Measuring transit time of reflected waves
• CPC Class Codes: G01F 23/2965 : Measuring attenuation of transmitted waves
• CPC Class Codes: G01F 23/804 : containing circuits handling parameters other than liquid level
• CPC Class Codes: G01S 13/04 : Systems determining presence of a target based on relative movement of target G01S13/56
• CPC Class Codes: G01S 15/04 : Systems determining presence of a target
• CPC Class Codes: G01S 15/06 : Systems determining the position data of a target
• CPC Class Codes: G01S 15/87 : Combinations of sonar systems
• CPC Class Codes: G01S 15/88 : Sonar systems specially adapted for specific applications seismic or acoustic prospecting or detecting G01V1/00
• CPC Class Codes: G01S 15/931 : of land vehicles
• CPC Class Codes: G01S 17/88 : Lidar systems specially adapted for specific applications
• CPC Class Codes: G01S 17/89 : for mapping or imaging
• CPC Class Codes: G01S 7/417 : involving the use of neural networks
• CPC Class Codes: G01S 7/4802 : using analysis of echo signal for target characterisation; Target signature; Target cross-section
• CPC Class Codes: G01S 7/539 : using analysis of echo signal for target characterisation; Target signature; Target cross-section
• CPC Class Codes: G06V 40/10 : Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
• CPC Class Codes: G10K 2210/1282 : Automobiles
• CPC Class Codes: G10K 2210/3219 : Geometry of the configuration
• CPC Class Codes: Y10S 367/908 : Material level detection, e.g. liquid level

Abstract

The displacement sensor of this invention comprises a tube combined with a sonic transmitter and receiver. The tube acts as a waveguide for the sonic waves and a processor determines whether the tube has changed in length or has been constricted which, in either case, changes the pattern of sonic waves traveling from the transmitter to the receiver. In some applications, the transmitter and receiver are at different ends of the tube. In these cases, the attenuation in sound energy reaching the receiver, caused by the tube being squeezed at at least one point, is measured and the amount of cross action area reduction is determined. In other applications, the transmitter and receiver are at the same end of the tube and, in some of these cases, the transmitter and receiver are the same transducer. When the transmitter and receiver are at the same end of the tube, the receiver receives sonic waves reflected from a constriction in the tube and the time between transmission and reception of the waves permits the processor to determine the location along the tube of the constriction. The measuring device of this invention can also be used to measure the change in length of the tube or effective length, such as when the tube is partially filled with a liquid.

Claims

1. A device for determining the displacement of an object relative to a stationery support comprising:

a) a compliant tube having two ends and a bore therein, said bore of said tube having a length, said tube being in contact with said object and positioned so that the displacement of said object against said tube relative to said support causes said tube to deform to thereby decrease the cross section area at some location along said length of said bore of said tube;

b) a sonic transmitter attached to one end of said tube;

c) a sonic receiver attached to one end of said tube; and

d) processor means connected to said sonic transmitter and said sonic receiver;

wherein said processor means causes said sonic transmitter to send sonic waves into said tube where said sonic waves are modified by the amount of change of said tube bore cross section area at said location along said length of said bore, after which, said modified waves are received by said receiver which produces a signal which is processed by said processor means to determine the amount of constriction of said tube caused by said object.

2. The invention in accordance with claim 1 wherein said receiver is at a different end of said tube from said transmitter.

3. The invention in accordance with claim 1 further comprising an output signal from said processor means when said amount of constriction exceeds a predetermined value.

4. The invention in accordance with claim 1 wherein said receiver is at the same end of said tube as said transmitter.

5. The invention in accordance with claim 4 wherein i) at least some of said modified waves are reflected back to said receiver from the location of said tube bore cross section area change, and ii) said processor means calculates the distance to said location from the time required for said waves to travel from said transmitter to said receiver.

6. The invention in accordance with claim 5 further comprising an output signal from said processor means when said location of said deflection exceeds a first predetermined distance from said transmitter along said length and is less than a second predetermined distance.

7. A device for detecting an obstacle in the path of a moving object against a stationery support comprising:

a) a compliant tube having two ends and a bore therein, said bore having a length, said tube positioned against said support to contact said obstacle when said obstacle is in the path of said moving object so that said obstacle contacts and causes a deformation of said tube decreasing the cross section area at some location along said length of said bore of said tube;

b) a sonic transmitter attached to one end of said tube, said sonic transmitter producing sonic waves within said tube;

c) a sonic receiver attached to one end of said tube, said sonic receiver receiving said sonic waves produced by said transmitter and producing an electric signal representative of said received sonic waves; and

d) detection means electrically connected to said sonic receiver, said detection means providing an output signal when said electric signal deviates by a predetermined amount from a signal characteristic of when no obstacle is in contact with said tube;

wherein said sonic transmitter sends sonic waves into said tube where said sonic waves are modified by the change of said tube bore cross section area, after which, said modified waves are received by said receiver which produces an electric signal representative of said modified waves, and said electric signal is fed into said detector which determines whether an obstruction is present and if so provides said output signal.

8. The invention in accordance with claim 7 wherein said moving object is a door.

9. The invention in accordance with claim 7 wherein said moving object is a window.

10. The invention in accordance with claim 7 wherein said moving object is a sunroof.

11. The invention in accordance with claim 7 wherein said moving object is a vehicle trunk lid.

12. The invention in accordance with claim 7 wherein said tube is mounted on said moving object.

13. The invention is accordance with claim 7 wherein said tube is mounted on a fixed object of said stationery support in the path of said moving object.

14. A device for determining the displacement of an object relative to a stationery support comprising:

a) a tube having two ends and a bore therein, said tube constructed of elastomeric and reinforcing materials permitting axial stretching of said tube but resisting radial deformation, said tube in contact with said object and having said two ends each connected to a point of said support and positioned to elongate in response to the normal displacement of said object against said tube;

b) a sonic transmitter attached to one end of said tube, said sonic transmitter producing sonic waves within said tube in response to an electric signal;

c) a sonic receiver attached to one end of said tube, said sonic receiver receiving said sonic waves produced by said transmitter and producing an electric signal representative of said received sonic waves; and

,

d) processor means electrically connected to said sonic transmitter and said sonic receiver,

wherein, said processor means produces an electric signal which is fed into said sonic transmitter causing it to send sonic waves into said tube to said receiver, said receiver receives said sonic waves and produces said representative electric signal which is processed by said processor means to determine the amount of elongation of said tube caused by said object based on the time it takes for said waves to travel from said transmitter to said receiver.

15. The invention in accordance with claim 14 wherein said object further comprises an elastically supported platform for supporting an article there on and the normal displacement of said platform is representative of the weight of said article, and said amount of elongation of said tube is representative of the weight of said article.

16. The invention in accordance with claim 14 wherein said platform is the seat of a vehicle and said article rests on said seat.

17. A device for determining the crush of a vehicle experiencing a crash comprising:

a) a compliant tube having two ends and a bore therein, said tube positioned on said vehicle so that the crush of a portion of said vehicle contacts and causes said tube to deform thereby decreasing the cross sectional area of said bore at some location along said length of said bore of said tube;

b) a sonic transmitter attached to one end of said tube, said sonic transmitter producing sonic waves within said tube;

c) a sonic receiver attached to one end of said tube, said sonic receiver receiving sonic waves produced by said transmitter and producing an electric signal representative of said received sonic waves; and

d) detection means electrically connected to said sonic receiver, said detection means providing an output signal when said received signal deviates from a normal signal characteristic of no tube deformation by a predetermined amount, said output signal indicating that said crush of said vehicle has occurred;

wherein, said sonic transmitter sends said sonic waves into said tube where said sonic waves are modified by the change of said tube bore cross sectional area caused by a crushing of a portion of a vehicle which deforms and contacts said tube, after which, said modified waves are received by said receiver which produces said representative electrical signal which is fed into said detector which determines whether said crush has occurred and if so provides said output signal.

18. The invention in accordance with claim 17 wherein said device is mounted adjacent the rear of a vehicle to sense rear impacts.

19. The invention in accordance with claim 17 wherein said device is mounted adjacent the side of a vehicle to sense side impacts.

20. The invention in accordance with claim 17 wherein said device is mounted adjacent the front of a vehicle to sense frontal impacts.