MICROWAVE CRASH SENSOR FOR AUTOMOBILES

• US 3,760,415 A
• Filed: 12/23/1971
• Issued: 09/18/1973
• Est. Priority Date: 12/23/1971
• Status: Expired due to Term

• Current Assignee: Holmstrom F. Ross, John B. Hopkins
• Original Assignee: Holmstrom F. Ross, John B. Hopkins
• Inventors: Hopkins, John B., Holmstrom, F. Ross
• Primary Examiner(s): Borchelt, Benjamin A.
• Assistant Examiner(s): Montone, G. E.
• Application Number:
  US05/211,579
• Time in Patent Office: 635 Days
• Field of Search: 343/7ED,112CA,113R,1ST,5PD,8,9 180/98
• US Class Current: 342/59
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/9323 Alternative operation using light waves
• CPC Class Codes: G01S 2013/9324 Alternative operation using ultrasonic waves
• CPC Class Codes: G01S 2013/93271 in the front of the vehicles

Abstract

Disclosed is a vehicle safety system in which a bistatic Doppler system senses objects in the path of a subject vehicle and activates a passenger restraint device, such as an inflatable '"'"''"'"''"'"''"'"'air-bag'"'"''"'"''"'"''"'"' in response thereto. In another preferred embodiment, the Doppler system is combined with mechanical sensing apparatus to deploy the restraint device during lower speed collisions. In addition, a system is disclosed that deploys a passenger restraint device only in response to simultaneous signals from two Doppler systems.

Claims

1. A safety system for protecting the passengers of a vehicle from collision related injury and comprising the following:

transmitter means coupled to directional transmitter antenna means for transmitting a beam of energy into a given zone ahead of a vehicle supporting said transmitter means and antenna means;

receiver means coupled to directional receiving antenna means oriented so as to receive energy only from a limited intersection portion of said given zone, said intersection portion of said given zone lying directly in front of the vehicle during forward movement thereof;

Doppler means coupled to said transmitter means and said receiver means to detect Doppler signals produced by energy reflections from objects within said intersection portion of said given zone, said Doppler means including logic means comprising amplitude threshold means providing an approximate target size threshold, Doppler frequency threshold means providing a closing rate threshold, and Doppler cycle count threshold means providing a predetermined minimum number of Doppler cycles threshold; and

active passenger protection means responsive to said Doppler means to protect passengers when objects are detected within said intersection portion of said given zone.

2. A system according to claim 1 wherein said transmitter means comprises an ultrasonic transmitter and said receiver means comprises an ultrasonic receiver.

3. A system according to claim 1 wherein said transmitter means comprises a microwave transmitter and said receiver means comprises a microwave receiver.

4. A system according to claim 1 wherein said transmitter means comprises two transmitters and two transmitter antennas so as to produce two generally superimposed transmitted beams of substantially different frequencies, said receiver means comprises two receiver and receiver antenna combinations, one of said combinations being responsive to one of the transmitted beams and the other one of said combinations being responsive to the other transmitted beam, said Doppler means comprises a first Doppler detector coupled to said one combination and a second Doppler detector coupled to said other combination, and wherein said active passenger protection system comprises trigger means for activating said active passenger protection means only in response to enabling signals received simultaneously from both said one combination and said other combination.

5. A system according to claim 1 including impact sensor means actuated by impact, a second Doppler frequency threshold means of a lower value than said first Doppler frequency tHreshold means to provide a lower closing rate threshold, and where said protection means comprises trigger means activated only in response to both object detection by the signal from said second Doppler frequency threshold means and activation of said impact sensor means.

6. A system according to claim 1 wherein said intersection portion of said given zone is located in a region less than 10 feet ahead of the vehicle.