Vehicle anti-collison device

Claim 2

A vehicle anti-collision device comprising: a rangefinder for mounting inside a following vehicle near to a windshield thereof for measuring a distance of said vehicle from a leading vehicle, distance sampling means coupled to the rangefinder for sampling measured distances at predetermined time intervals, self-speed determination means for measuring a self-speed of the following vehicle, safety time determination means coupled to the distance sampling means and to the self-speed determination means and responsive to the measured self-speed of the following vehicle for determining a safety time between the following and leading vehicles; comparing means coupled to the safety time determination means for comparing said safety time with a predetermined threshold, and alarm means coupled to the comparing means for generating an alarm if the safety time is less than said predetermined threshold, wherein the rangefinder is coupled to a steering mechanism of the following vehicle and includes: a laser light source for emitting a beam of laser light, a first component of which is reflected by the windshield, a second component of which passes through the windshield of the following vehicle so as to be reflected by the leading vehicle, detector means for receiving said first and second components and generating respective first and second detector signals, timing means coupled to the detector means and responsive to the first and second detector signals for measuring an elapsed time between the detection of the first and second components, distance determination means coupled to the timing means and responsive to said measured elapsed time for determining the distance between the following and leading vehicles, turning angle determination means coupled to the steering mechanism for determining a turning radius thereof, lane differentiation means coupled to the turning angle determination means and responsive to said turning radius, to a known dispersion of said laser beam, to a known lane width and to a known vehicle width for determining a maximum distance between the following vehicle and the leading vehicle for which the two vehicles are in identical lanes, and switching means coupled to the lane differentiation means, to the turning angle determination means and to the detector means for intercepting the reflected first component of the laser beam and directing it to the detector means only if the two vehicles are in identical lanes.

Claim 3

The device according to claim 1, further including leading speed determination means for determining a speed of the leading vehicle.

Claim 4

The device according to claim 2, wherein the leading speed determination means includes: closing speed determination means coupled to the distance sampling means and responsive to a difference in successive sampled distances and said predetermined time interval for determining a closing speed of the following vehicle with respect to the leading vehicle, and difference means for subtracting said closing speed from the self-speed of the following vehicle.

Claim 5

The device according to claim 2, further including a display for displaying the speed of the leading vehicle.

Claim 6

The device according to claim 1, further including a display for displaying the safety time.

Claim 7

The device according to claim 1, wherein the self-speed determination means is coupled to a speedometer of the following vehicle.

Claim 8

The device according to claim 1, wherein the self-speed determination means includes: at least one light-reflective strip on a drive shaft of the following vehicle, a source of light directed towards the drive shaft so as to strike the light-reflective strip during each revolution of the drive shaft, a detector for receiving a reflected beam of light reflected by the light-reflective strip and generating a detector signal, a clock, a counter coupled to the clock and to the detector for counting a number of detector signals in a predetermined time interval so as to determine a number of revolutions of the drive shaft in said time interval thereby permitting the self speed of the following vehicle to be calculated.

Claim 9

The device according to claim 1, wherein the turning angle determination means is responsive to a known wheel base of the vehicle and to an offset angle of the steering mechanism relative to a predetermined angle corresponding to a straight trajectory of the vehicle.

Claim 10

The device according to claim 1, further including safety time adjustment means for adjusting said predetermined threshold.

Claim 11

The device according to claim 1, wherein the rangefinder includes a sensitivity selection means for adjusting a sensitivity thereof.

Claim 12

A vehicle anti-collision device comprising: a rangefinder for mounting inside a following vehicle near to a windshield thereof and being coupled to a steering mechanism thereof for measuring a distance of said vehicle from a leading vehicle, distance sampling means coupled to the rangefinder for sampling measured distances at predetermined time intervals, self-speed determination means for measuring a self-speed of the following vehicle, safety time determination means coupled to the distance sampling means and to the self-speed determination means and responsive to the measured self-speed of the following vehicle for determining a safety time between the following and leading vehicles, comparing means coupled to the safety time determination means for comparing said safety time with a predetermined threshold, and alarm means coupled to the comparing means for generating an alarm if the safety time is less than said predetermined threshold; the rangefinder including: a laser light source for emitting a beam of laser light a first component of which is reflected by the windshield, a second component of which passes through the windshield of the following vehicle so as to be reflected by the leading vehicle, detector means for receiving said first and second components and generating respective first and second detector signals, timing means coupled to the detector means and responsive to the first and second detector signals for measuring an elapsed time between the detection of the first and second components, and distance determination means coupled to the timing means and responsive to said measured elapsed time for determining the distance between the following and leading vehicles, and said device further including: turning angle determination means coupled to the steering mechanism for determining a turning radius thereof, lane differentiation means coupled to the turning angle determination means and responsive to said turning radius, to a known dispersion of said laser beam, to a known lane width and to a known vehicle width for determining a maximum distance between the following vehicle and the leading vehicle for which the two vehicles are in identical lanes, and switching means coupled to the lane differentiation means, to the turning angle determination means and to the detector means for intercepting the reflected first component of the laser beam and directing it to the detector means only if the two vehicles are in identical lanes, and an elevation adjustment means coupled to the laser light source for adjusting an elevation angle of the laser beam such that the elevation angle is substantially constant regardless of load distribution within the following vehicle.

Claim 13

A vehicle anti-collision device comprising: a rangefinder for mounting inside a following vehicle near to a windshield thereof and being coupled to a steering mechanism thereof for measuring a distance of said vehicle from a leading vehicle, distance sampling means coupled to the rangefinder for sampling measured distances at predetermined time intervals, self-speed determination means for measuring a self-speed of the following vehicle, safety time determination means coupled to the distance sampling means and to the self-speed determination means and responsive to the measured self-speed of the following vehicle for determining a safety time between the following and leading vehicles, comparing means coupled to the safety time determination means for comparing said safety time with a predetermined threshold, and alarm means coupled to the comparing means for generating an alarm if the safety time is less than said predetermined threshold; the rangefinder including: a laser light source for emitting a beam of laser light a first component of which is reflected by the windshield, a second component of which passes through the windshield of the following vehicle so as to be reflected by the leading vehicle, detector means for receiving said first and second components and generating respective first and second detector signals, timing means coupled to the detector means and responsive to the first and second detector signals for measuring an elapsed time between the detection of the first and second components, and distance determination means coupled to the timing means and responsive to said measured elapsed time for determining the distance between the following and leading vehicles, and said device further including: turning angle determination means coupled to the steering mechanism for determining a turning radius thereof, lane differentiation means coupled to the turning angle determination means and responsive to said turning radius, to a known dispersion of said laser beam, to a known lane width and to a known vehicle width for determining a maximum distance between the following vehicle and the leading vehicle for which the two vehicles are in identical lanes, and switching means coupled to the lane differentiation means, to the turning angle determination means and to the detector means for intercepting the reflected first component of the laser beam and directing it to the detector means only if the two vehicles are in identical lanes, and an elevation adjustment means coupled to the laser light source for adjusting an elevation angle of the laser beam such that the elevation angle is substantially constant regardless of load distribution within the following vehicle.

Claim 14

A vehicle anti-collision device comprising: a rangefinder for mounting inside a following vehicle near to a windshield thereof for measuring a distance of said vehicle from a leading vehicle, distance sampling means coupled to the rangefinder for sampling measured distances at predetermined time intervals, self-speed determination means for measuring a self-speed of the following vehicle, safety time determination means coupled to the distance sampling means and to the self-speed determination means and responsive to the measured self-speed of the following vehicle for determining a safety time between the following and leading vehicles; comparing means coupled to the safety time determination means for comparing said safety time with a predetermined threshold, and alarm means coupled to the comparing means for generating an alarm if the safety time is less than said predetermined threshold; wherein the rangefinder includes: a laser light source for emitting a beam of laser light a first component of which is reflected by the windshield, a second component of which passes through the windshield of the following vehicle so as to be reflected by the leading vehicle, detector means for receiving said first and second components and generating respective first and second detector signals, timing means coupled to the detector means and responsive to the first and second detector signals for measuring an elapsed time between the detection of the first and second components, and distance determination means coupled to the timing means and responsive to said measured elapsed time for determining the distance between the following and leading vehicles; and wherein a laser frequency of the laser light source is randomly selected between predetermined lower and upper thresholds in respect of a specific vehicle, and said device further provided filtering means for filtering out a received signal whose frequency differs from said laser frequency, thereby preventing false alarms owing to receipt of spurious signals in a region of said specific vehicle.

Claim 15

A vehicle anti-collision device comprising: a rangefinder for mounting inside a following vehicle near to a windshield thereof for measuring a distance of said vehicle from a leading vehicle, distance sampling means coupled to the rangefinder for sampling measured distances at predetermined time intervals, self-speed determination means for measuring a self-speed of the following vehicle, safety time determination means coupled to the distance sampling means and to the self-speed determination means and responsive to the measured self-speed of the following vehicle for determining a safety time between the following and leading vehicles; comparing means coupled to the safety time determination means for comparing said safety time with a predetermined threshold, and alarm means coupled to the comparing means for generating an alarm if the safety time is less than said predetermined threshold; wherein the rangefinder includes: a laser light source for emitting a beam of laser light a first component of which is reflected by the windshield, a second component of which passes through the windshield of the following vehicle so as to be reflected by the leading vehicle, detector means for receiving said first and second components and generating respective first and second detector signals, timing means coupled to the detector means and responsive to the first and second detector signals for measuring an elapsed time between the detection of the first and second components, and distance determination means coupled to the timing means and responsive to said measured elapsed time for determining the distance between the following and leading vehicles; and wherein a laser frequency of the laser light source is randomly selected between predetermined lower and upper thresholds in respect of a specific vehicle, and said device further provided filtering means for filtering out a received signal whose frequency differs from said laser frequency, thereby preventing false alarms owing to receipt of spurious signals in a region of said specific vehicle.

Claim 16

A vehicle anti-collision device comprising: a rangefinder for mounting inside a following vehicle near to a windshield thereof for measuring a distance of said vehicle from a leading vehicle, distance sampling means coupled to the rangefinder for sampling measured distances at predetermined time intervals, self-speed determination means for measuring a self-speed of the following vehicle, safety time determination means coupled to the distance sampling means and to the self-speed determination means and responsive to the measured self-speed of the following vehicle for determining a safety time between the following and leading vehicles; comparing means coupled to the safety time determination means for comparing said safety time with a predetermined threshold, and alarm means coupled to the comparing means for generating an alarm if the safety time is less than said predetermined threshold; the rangefinder including: a laser light source for emitting a beam of laser light a first component of which is reflected by the windshield, a second component of which passes through the windshield of the following vehicle so as to be reflected by the leading vehicle, detector means for receiving said first and second components and generating respective first and second detector signals, timing means coupled to the detector means and responsive to the first and second detector signals for measuring an elapsed time between the detection of the first and second components, and distance determination means coupled to the timing means and responsive to said measured elapsed time for determining the distance between the following and leading vehicles; and further including an elevation adjustment means coupled to the laser light source for adjusting an elevation angle of the laser beam such that the elevation angle is substantially constant regardless of load distribution within the following vehicle.

Claim 17

A vehicle anti-collision device comprising: a rangefinder for mounting inside a following vehicle near to a windshield thereof for measuring a distance of said vehicle from a leading vehicle, distance sampling means coupled to the rangefinder for sampling measured distances at predetermined time intervals, self-speed determination means for measuring a self-speed of the following vehicle, safety time determination means coupled to the distance sampling means and to the self-speed determination means and responsive to the measured self-speed of the following vehicle for determining a safety time between the following and leading vehicles; comparing means coupled to the safety time determination means for comparing said safety time with a predetermined threshold, and alarm means coupled to the comparing means for generating an alarm if the safety time is less than said predetermined threshold; the rangefinder including: a laser light source for emitting a beam of laser light a first component of which is reflected by the windshield, a second component of which passes through the windshield of the following vehicle so as to be reflected by the leading vehicle, detector means for receiving said first and second components and generating respective first and second detector signals, timing means coupled to the detector means and responsive to the first and second detector signals for measuring an elapsed time between the detection of the first and second components, and distance determination means coupled to the timing means and responsive to said measured elapsed time for determining the distance between the following and leading vehicles; and further including an elevation adjustment means coupled to the laser light source for adjusting an elevation angle of the laser beam such that the elevation angle is substantially constant regardless of load distribution within the following vehicle.