|Title of Invention||
A METHOD FOR DETECTION OF COLLISION WITH AN OBJECT OR ANOTHER VEHICLE USING NARROW LIGHT BEAMS
|Abstract||A new method and the required system for detecting coUision in a non contact manner are proposed. The proposed system employs two sets of narrow Ught beams which intersect at two distinct points ahead of the vehicle on which the system is mounted. The method of detection is based on the fact that when another vehicle or object passes the zone of these distinct points, due to relative speeds, spots are formed on it and the spot is seen by a sensor having a narrow view zone thus generating electrical signals which are recorded in a suitable computer. The time of receiving the signals is also recorded in the computer and the information is processed in the computer in specific programmed manner to give alarm or commands to various safety systems such as air bag deployment, auto braking, fuel cut off, clutch disengagement systems.|
|Full Text||A method and system for detection of collision using narrow light beams
Field of Application
This invention relates to a method and a system for detection of a possible collision before the actual collision takes place. It is a non-contact method of collision detection. This is especially more suitable for vehicles/ automobiles. This also can be used for any other type of mobile systems viz. boats.
Detection of collision is often required to bring in various safety measures which protect the passengers. Various methods are in use. Out of these, non-contact methods i.e. methods by which collision can be detected before the actual contact are advantageous. The principles of radar and ultrasound are being proposed by various inventors. However, these techniques are not widely employed in commercial road vehicles. There is a possibility of getting a signal from an oppositely traveling vehicle which is not in a course of collision. At present, only shock sensors, (e.g. MEMS accelerometer sensors) which detect collision after the collision takes place are in wide use for commercial road vehicles. The purpose of these sensors is to provide additional safety (viz. air bag deployment) against injuries to passenger.
A new method of detecting a collision in a non-contact manner is proposed which does not have the disadvantages of getting signals ft-om passing by vehicles. The signal obtained can be used for air bag deployment, application of brakes, cutting off the fuel supply, disengagement of clutch etc.
Brief description of drawings
Fig.l shows top view and side view of basic arrangement on a vehicle to create a spot ahead of it using two light beams.
Fig.2 shows top view, side view and front view of the proposed arrangement of a system on vehicle for detection of collision.
Fig.3 shows arrangement of beams for obtaining a longer intersection zone.
Fig.4 shows arrangement of sensor and filter inside a housing tube.
Fig.5 shows a system for introducing a light source in front of the sensor.
New method of detection of objects or oppositely moving vehicles (see Fig.l)
A narrow beam of light forms a spot when it falls on an object, which can be detected by a suitable sensor e.g. a suitable photo detector. For the light spot to be formed at a particular distance from vehicle (1), so that a vehicle with in that particular distance only be detected, two or more narrow beams of light (2) are made to intersect at a suitable point called "focus" (3), ahead of vehicle. When another object e.g. another vehicle approaches the vehicle (1), it has to pass through the focus location and hence a spot can be seen on the body of approaching vehicle for a very short duration. If this spot is seen by a suitable photo detector, then a signal can be generated. Since the spot appears for a very short duration, a pulse of narrow width is generated by the photo detector.
The above explained method is the basis of the detailed method proposed below for detection of collision.
Detailed method /proposed method
Two sets of narrow light beams (e.g. red color low energy laser pointer lights) are placed in a manner on the vehicle as shown in Fig.2, so that each set focuses at one point ahead of the vehicle. Hence there are two points of focus which are located at a distance of di and d2. The beams originating from the light sources located on the inner set (5) focus at a distance less than that of the corresponding focus of beams originating from the set of light sources located on the outer set (6).
Further, on each set the sources are positioned such that the volume consisting of intersection of light beams make a small cylinder (8) along the direction of di (see Fig.3) i.e. the meeting prints of the beams originating from a set form a cylinder of small diameter and small length (Adi). When an object is brought to a distance of di from the light source, a spot is formed on the object and the spot remains seen till the object moves from a distance di to (dp Adi) towards the light source.
In the similar manner, the focus points of the beams from outer set occupy a small cylindrical volume (9) with small diameter and a small length Ad2 at a distance of da from the light source.
A sensor (7) is placed inside a long tube (10) so that the view angle is very narrow (see Fig.4). The sensor can see only light beams directly falling on it and not much of the reflected beams because the reflected beams from the internal wall of tube (10) escapes from the openings (11) provided on the long tube (10) in a manner as shown in Fig.4.
The sensor (7) is placed such that it's axis of sight passes through the focus points i.e. through the small light cylinders (8) & (9) described above. Hence, when the object is not at focus region i.e. (8) & (9), the spot, if formed on object due to falling of light beam, will not be seen by the sensor (7) as the spot does not fall in the line of sight or more precisely view zone of the sensor.
When the object crosses the focus region (9) a signal is generated for short period i.e. a voltage pulse is generated by sensor. Similarly, when the object crosses the focus region (8) a second signal is generated.
The vehicle (1) may be traveling at a higher speed than object i.e. another vehicle going ahead of it in the same direction. Hence in this case also the object encounters the
focus region of the light beams and hence a signal is generated. To distinguish objects moving in same direction ahead of vehicle (1) from the object moving in opposite direction and which is in the course of a head on collision, the following methodology may be adopted.
Two pulses are generated in either case i.e. (i) the case when vehicle ahead is moving at a slower speed in the same direction and (ii) when there is a vehicle ahead traveling in opposite direction at any speed and is in the line of the vehicle (1). The time difference between the two pulses (At) is recorded by a suitable electronic measuring system. Then, (At) is compared with [(da - di)A^]. "V" is the speed of the vehicle (1), which is measured by any suitable sensor that converts angular speed or number of revolutions of the wheel into linear speed of vehicle using value of radius of the wheel. The speed is registered in the memory of the computer. The speed information may be updated in the memory every 0.25 sec. or at any suitable interval and at the same intervals [(da - di)/V] is calculated and stored as "K". This K is compared against (At) as soon as the second pulse is generated by sensor. If (At) is more than K, then the vehicle ahead is moving in the same direction. In this case, depending on the difference, a suitable alarm can be given to the driver. If (At) is less than K, then it indicates that vehicle ahead is moving in opposite direction. This is a dangerous situation. Hence the computer gives a danger alarm and activates all safety features as described earlier. If it is equal or nearly equal to K, then the object ahead is stationery. In this case also safety devices can be activated.
The light beams can be arranged such that the line joining the two foci makes an angle with the direction of vehicle travel as shown in Fig.l. In this case the constant K is equal to [(da - di) cos 0 /V], where 9 is the angle of inclination of center line (12) w.r.t direction of travel of (1).
To avoid getting of signals in a situation where the vehicles travel in congested traffic, a threshold velocity of vehicle may be used, below which no signal for activation of safety systems be given by computer. The system shall be active only if the velocity of vehicle is above the threshold speed. The value of threshold speed can be kept at any suitable value.
Color of light beams shall be preferably red. Suitable filters (13), which will transmit light corresponding to wavelength of light beams, are put ahead of the sensor (7) in the sensor housing tube (10). A water jet cleaning system (14) may be employed for on line cleaning at some interval based on a detectability of a weak intensity light of the same color; the light source (15) for this can be brought in line with the line of sight of the sensor by an oscillating lever (16) intermittently, as shown in Fig.5.
Background color problem
To distinguish the spot made on another vehicle or object (by the intersecting light beams) from the color of object, which in some case may be same as that of spot i.e. red, the computer distinguish continuous signal (received from the object) from the pulse generated when the object passes through the focus region. If the signal exists continuously for duration more than certain threshold, then alarm signal may be generated by computer. Altemately, upon getting a continuous signal the computer may
reset the threshold level of signal generated by the sensor at a higher value and only light spot, which is of more intensity than usual red color painted on vehicles, be seen by the sensor.
The distance of the focus points can be increased or decreased depending on the speed of the vehicle requiring safety (i.e. the vehicle on which the sensor is put) employing an automatic system which will change the angle of the light beams by turning the holder of light sources accordingly.
This device can be used to detect any lateral collision (i.e. approach of a vehicle from lateral direction) or from back side by suitably placing it on the vehicle requiring safety. The value of K is to be accordingly calculated. For detection of lateral collision single point focus is sufficient.
Claims of the Invention
1. A system consisting of two sets, called outer set and inner set, of near monochromatic
light beams sources emitting narrow beams with very less divergence (e.g. low
energy red color laser spot-light beams) arranged on the vehicle in such a manner that
light beams emerging from each set meet at a point ahead of vehicle called "focus
points" as shown in Fig.2 wherein
(i) the said two focus points are separated by a distance "d" and line joining the two focus points, called "Centre line" is lying on the mid longitudinal plane of the vehicle and the said focus points lie at a distance of a di and dj from the position of a suitable photo detector called herein as 'sensor", which is placed along the said center line at any suitable location on the vehicle.
(ii) the said light beam sources in each set are placed in such a manner that the
beam intersections at said focus point make a small volume with a small
diameter and a small length constituting a small cylindrical volume with
axis d cylinder lying along said centre line.
2. The system claimed in claim 1 wherein
(i) the said sensor is located inside a long concentric tube called housing tube so that the vision angle is very narrow; the said housing tube is provided with openings in the manner shown in Fig.4 so as to allow only direct beams from the narrow region called view zone containing said two focus points and maximum of the light entering from outside the said view zone gets reflected from the internal surface of the said housing tube and escape out of it through said openings.
(ii) a suitable color filter (e.g. narrow band pass color filter made of any suitable material such as special polymers) is placed in side the said housing tube in front of the said sensor so that only the color of light emitted by light sources is detected.
3. The method of detection of presence of another vehicle ahead, herein called as
"object", moving in opposite direction or stationery, using the system as claimed in
claim 1 and 2, is based on the fact that when the said object comes to the region of
outer focus, a spot is formed on the object which can be seen by the said sensor and a first pulse output is generated on account of the fact that the object stays in the zone of the focus point consisting of said cylindrical volume for a very small period; the pulse and the time are registered in a suitable computer through a suitable clock and electronic circuit or device; a second signal or pulse and time are registered when said object comes to the region of second focus point; the time difference (At) between the two signals or pluses is calculated and compared with a factor "K" which is equal to "d" divided by velocity of vehicle "V; the velocity of vehicle being continuously registered in the computer at a suitable frequency from a suitable speed sensor generating the speed information continuously.
The method of detection of presence of another vehicle as claimed in claim 3 in which, If (At) is less than K (which means that the said object is moving in opposite direction) then computer gives a signal to activate safety systems such as air bag deployment, auto braking , cutting off fuel supply, disengaging the clutch etc. and if (At) is more than K (which means that the said object is moving in the same direction) or if (At) is same as K (which means that the said object is stationery) an alarm is activated cautioning the driver.
The method of detection of presence of another vehicle as claimed in claim 3 wherein an alarm is generated on receiving of first pulse irrespective of the time after which second signal or pulse is received.
The method of detection of presence of another vehicle as claimed in claim 3 and 4 with the difference that instead of using two sets of light beams a single set is used e.g. for lateral collision detection, for which the system shall be placed on the vehicle in the direction of anticipation of collision.
The method of detection of presence of another vehicle as claimed in claim 3 and 4 wherein the system as described in claim 1 and 2 is such that the said center line is inclined downwards as shown in Fig.2 or the said center line is horizontal or inclined upwards depending on the location of the system on the vehicle and the angle of inclination is varied by means of a suitable drive along with an angle detector so that 'K' is calculated accordingly; K being equal to 'd' multiplied by cosine of angle of inclination and whole divided by velocity of vehicle 'V.
A method and system for detection of a head on collision, collision from back side or a collision from lateral side in a non contact maimer, substantially as herein described and illustrated in the accompanying drawings.
Summary of the invention
A new method and the required system for detecting coUision in a non contact manner are proposed. The proposed system employs two sets of narrow light beams which intersect at two distinct points ahead of the vehicle on which the system is mounted. The method of detection is based on the fact that when another vehicle or object passes the zone of these distinct points, due to relative speeds, spots are formed on it and the spot is seen by a sensor having a narrow view zone thus generating electrical signals which are recorded in a suitable computer and the information is processed in the computer to give alarm or commands for air bag deployment, auto braking, fuel cut off, clutch disengagement etc. The main advantage of this system is that it will not detect any vehicle moving in opposite direction which is not in the course of collision. The system can be used for detecting head on or lateral collision or approach of other vehicles from back side.
|Indian Patent Application Number||2406/CHE/2007|
|PG Journal Number||19/2013|
|Date of Filing||24-Oct-2007|
|Name of Patentee||CH. RABI KUMAR|
|Applicant Address||248, PRASANTI HILLS, BLOCK/PHASE-III, MEERPET VILLAGE, SAROOR NAGAR MANDAL, R R DISTRICT, HYDERABAD - 500 097.|
|PCT International Classification Number||B60R 21/00|
|PCT International Application Number||N/A|
|PCT International Filing date|