ANTI-CRASH RADIO DETECTOR FOR AUTOMOTIVE VEHICLES

• US 3,689,882 A
• Filed: 12/29/1970
• Issued: 09/05/1972
• Est. Priority Date: 12/29/1969
• Status: Expired due to Term

• Current Assignee: Rene Dessailly
• Original Assignee: Rene Dessailly
• Inventors: Dessailly, Rene
• Primary Examiner(s): Alvin H. Waring
• Application Number:
  US05/102,427
• Time in Patent Office: 616 Days
• Field of Search: 340/22,23,26,29,31,32,33,34,53,61,258,282 180/98
• US Class Current: 340/903
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/93185 Controlling the brakes
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/9322 using additional data, e.g. driver condition, road state or weather data
• CPC Class Codes: G01S 2013/9325 for inter-vehicle distance regulation, e.g. navigating in platoons
• CPC Class Codes: G01S 2013/93271 in the front of the vehicles

Abstract

Anti-crash radio-detector system for automotive vehicles adapted to take due account of all traffic conditions and operate efficiently for preventing an accident when an obstacle is detected ahead. This system is characterized in that it comprises a radioelectric or radar detector, a device for producing from the information delivered by said detector another information concerning the approach speed of the equipped vehicle, an electronic computer for determining a first safety distance and a second safety distance, a light and/or sound alarm device, and a device for controlling the braking system. This detector system is applicable to road and rail vehicles.

Claims

1. An anti-crash radio detector system for automotive vehicle, which comprises a radio-electric or radar detector projecting ahead of the vehicle a radio-electric wave beam of predetermined wave length and receiving the echoes reflecTed by fixed or movable obstacles appearing in front of the vehicle, a device for producing from the information delivered by said radar another information relative to the velocity of approach of the vehicle equipped with this detector in relation to a fixed or movable obstacle, an electronic computer for determining as a function of the various parameters inherent to the vehicle and to traffic conditions a first safety distance and, when the approach velocity of the vehicle is lower than or equal to the actual vehicle speed, determining a second safety distance, means for discriminating echoes reflected by obstacles being at a distance from said vehicle, shorter than the smallest of said first and second safety distances, means for determining at any time the distance between a fixed or movable obstacle detected by said radar and the vehicle equipped therewith, means for comparing the distance of said obstacle with said second safety distance, an alarm device connected to the output of said comparison means in order to operate said alarm device when the distance of said obstacle becomes shorter than the second safety distance, and a device for actuating the braking system which is also responsive to said comparison means.

2. An anti-crash radio detector system for automotive vehicle as set forth in claim 1, wherein said electronic computer receives at its inputs a first signal corresponding to the actual speed of the vehicle, said first signal being transmitted from a tachometric pick-up device, a second signal delivered from a switch adapted to be actuated by the driver of the equipped vehicle and corresponding to the road surface condition, a third signal emitted from a gyroscope and corresponding to an information related to the road gradient, and fourth, fifth, and sixth signals from three sections of a memory which are adapted to record an information corresponding to a theoretical curve giving the value of the braking distance as a function of the actual speed of the vehicle, an information delivered by a decelerometer and corresponding to the deceleration, and an information delivered by a generator and corresponding to the average or self-tested reaction time of the driver, respectively, said electronic computer comprising two stages of which the first one delivers the sum of a guard distance, of a first braking distance calculated from the value of the actual or momentary speed of the equipped vehicle, and a reaction distance for giving the aforesaid first safety distance and emit a first output signal corresponding to this first safety distance, the second stage of said computer determining the second safety distance by summing the guard distance, a second braking distance calculated from the value of the approach speed and the reaction distance in order to deliver to another output a second signal corresponding in value to the second safety distance.

3. An anti-crash radio-detector system as set forth in claim 2, wherein the input and output of said radar are connected to the output of a coder and to the input of a decoder, respectively, said decoder being connected through a delay-action device to the input of an AND gate delivering at one of its outputs a signal corresponding to the approach distance and at its other output a signal corresponding to the distance of the obstacle, and wherein a first comparator has two inputs receiving the one the signal corresponding to the actual speed of the vehicle and the other the signal corresponding to the approach speed, said first comparator comprising a first output delivering a signal when the approach speed is lower than the actual vehicle speed and to said computer for controlling the operation of the second stage thereof, and a second output delivering a signal when the approach speed is greater than the actual vehicle speed, said second output being connected to a member adapted to operate said alarm device intermittently.

4. An anti-crash radio-detector system as set forth in claim 3, wherein said secOnd output of said AND gate which delivers a signal corresponding to the distance of the obstacle is connected to one input of a second comparator receiving at another input the signal corresponding to the second safety distance, said comparator comprising a first output connected to said alarm device so as to cause said alarm device to operate intermittently in case the distance of said obstacle were shorter than the second safety distance, a second output also connected to said alarm device and delivering a signal after a predetermined time period corresponding to the driver'"'"''"'"'s reaction time for operating said alarm device continuously, and a third output connected through an ON-OFF switch to the braking system control device.

5. An anti-crash radio-detector system as set forth in claim 4, wherein a switch is inserted in the electric circuit controlling the braking system control device, said switch being closed when the vehicle is driven along a straight path and open when the front steering wheels are steered through a small predetermined angle.

6. An anti-crash radio-detector system as set forth in claim 4, wherein the outputs of the two stages which deliver respectively the signal corresponding to the first safety distance and the signal corresponding to the second safety distance are connected to the inputs of a discriminating comparator having its output connected to said AND-gate in order to select the shortest safety distance of the two and thus limit the radar information to this value.