EP1342214A2

EP1342214A2 - Electronic device to be installed aboard vehicles and/or boats, for obtaining information particularly useful in case of an accident

Info

Publication number: EP1342214A2
Application number: EP01985856A
Authority: EP
Inventors: Roberto Cavallotti; Sauro Silvestrini
Original assignee: N'Oxid SpA
Current assignee: N'Oxid SpA
Priority date: 2000-12-12
Filing date: 2001-12-10
Publication date: 2003-09-10
Also published as: WO2002048969A2; ITBO20000721A0; ITBO20000721A1; WO2002048969A3

Abstract

Parallelly to the real video shooting effected by at least one videocamera (22) or alternately to this, there is effected a virtual video shooting, which is more exact and coinciding, by means of accelerometric devices (2) and preferably by means of at least one electronic gyroscope (4), which consent the acquisition of kynematic information, information about the status of he vehicle of its engine, which are very exact and almost in real time at frequencies up to the order of one millisecond.

Description

TITLE:

"Electronic device to be installed aboard vehicles and/or boats, for obtaining information particularly useful in case of an accident" DESCRIPTION In the course of the practical realisation of the electronic device described in document WO 00 51083, there have been revealed as useful some important improvements and considerations which form the object of the present patent application. In order to better understand the scopes of the invention, it is useful to remind that the device according to the above mentioned document comprises a microprocessor unit which interacts with at least a memory element of continuous operation type, intended to memorise the video information coming from at least one microvideocamera mounted aboard the vehicle and directed toward the exterior, and digital information coming by the central unit belonging to the said vehicle, the said microprocessor unit being activated or de-activated by the ignition key of the vehicle itself and by an inertial sensor which modifies its status whenever the vehicle is subjected to an impact. There is moreover provided for a timer to delay the de- activation of said microprocessor unit for a predetermined time from the intervention of the said impact sensor so that inside said memory there remain stored the events relating for example to ten seconds prior to the accident and five seconds subsequent to the accident itself.

In the practical use of said device and of similar devices, for example described in the documents EP 0 005 532, EP 0 947 963, WO 96 00957, WO 99 0545 and GB 2 268 608, it has been verified that the only system of acquisition of video images and of some digital data coming from the electronic central unit aboard the vehicle, are not sufficient to guarantee the completeness of the information necessary to evaluate the responsibility of an accident. Frequently moreover the vehicles, and particularly those of older generation, are not provided with an electronic central unit which can supply digital data relating to the travel speed, to the acceleration, to the status of switched on or off and to other parameters, so that is becomes difficult and expensive to obtain these parameters and in any case to provide for a device which can be mounted easily and in a correct manner on every type of vehicle.

Notwithstanding the very good quality of the videocameras employed, for example of the type CCD, with glass lenses and with 1/100.000 second shutter, the filmed shooting according to the previous system can result to be lacking of information because there might happen the following:

- Whenever in the direction of travel opposed to the vehicle involved in the accident there cross in succession headlights on full, these may blind or dazzle the videocameras. - Independently from the location of the videocameras, during some moments of the day and of the year, the said videocameras can be dazzled by the sun which is low at the horizon.

- Sometimes the videocameras can be dazzled by the rain on the windshield.

- The glasses of the videocameras and of the vehicle can be misted or become dirty, so that for the correct operation of the said videocameras it would be necessary that the user provides for a periodic cleaning of the said glasses. It is evident that these conditions limit the performances and reliability of a detection system of optoelectronic type.

- While the device for the memorisation of the data can be installed at one point of the vehicle which is reasonably protected, the microvideocameras must be located in such positions able to "view", so that they are liable to be particularly exposed and can be mechanically involved in the accident and can be broken at the moment of the impact of the vehicle, thus preventing the film shooting relating to the after event .

- A further inconvenience derives form the timing of shooting of the videocameras, which does not take place according to real time. All the systems presently known, which employ solid state memory supports, when they were compelled to get into the "real" world and were compelled to take into account the need of realising shooting systems of good quality but of limited costs, have been compelled to choose reduced timings of shooting, around five photograms per second. This implies that between two successive photograms there pass about 200 milliseconds. Situations of vehicles which run at high speed and in different directions, could not show in a clear manner some particulars. For example, already at a speed of 180 km/h, in 200 milliseconds a vehicle travels about for 10 metres. The present optoelectronic systems could not detect some events with these timings. 5 The invention intends to obviate to these and other inconveniences and limitations of the present systems, by adopting the following idea of solution. Parallely to the real video shooting effected by the videocameras, or alternately to this, there is effected a virtual video shooting which is much more precise and coincident, by means of accelerometric devices and preferably also by means of an electronic

10 gyroscope, which consent of acquiring kynematic information about the vehicle very exact and almost in real time, with frequencies in the order of one millisecond. From these devices, it will be possible to obtain also parameters relating to the travel speed of the vehicle, to the acceleration, to the status of switched on or off of the engine and to other parameters of the vehicle itself, without getting same from the

15 central unit of the vehicle, as it is instead foreseen by the known technique.

Further characteristic features of the invention, and the advantages deriving therefrom, will appear better evident from the following description of a preferred embodiment of same, illustrated by way of non limiting example in the figures of the attached sheets of drawings, in which:

2.0 Figure 1 shows a block diagram of a portion of the device according to the invention, combined with the optoelectronic device of known type;

Figure 2 shows a block diagram of the device according to the invention, with or without combination with optoelectronic sensors;

Figure 3 is a flow chart illustrating the operation of the device according to the

25 invention;

Figure 4 shows a block diagram which consents to obtain information from traffic lights, to interface them with the data obtained by the device according to the invention, particularly if not provided with optoelectronic sensors.

In Figure 1 , reference numeral 1 indicates the optoelectronic device of known

30 type, provided with the microprocessor electronic unit Z interacting with a first and possibly with a second solid state digital memory device W and W1 intended to store information obtained through at least one microvideocamera A located in a protected position inside the motor vehicle and through the connection to the electronic central unit B of the same motor vehicle, which supplies the data relating to the date, hour, speed, acceleration and others. The processor Z can be activated and de-activated by means of the car ignition key C2 and can be de-activated by the intervention of an inertial sensor C1 which senses impacts imparted to the vehicle concurrently with an accident. Upon intervention of the sensor C, a timer T delays for a predetermined time the detection and storing of the data by the memory units W, W1 , so as to acquire sufficient data preceding the accident and subsequent to the accident itself. If the sensor C1 has a sufficiently high sensibility, it may happen that it intervenes also when the vehicle is subjected to stresses caused by road bumps. After the intervention of the sensor C1 there intervenes the timer T and simultaneously optical and/or acustical signallers E are activated, which signal to the user that the device is going to be blocked. During the interval of operation of the signallers E, if the vehicle is not involved in an accident, the user can act upon a button D in order to annul the alarm signal generated by said sensor C1 , by leaving the processor Z active or by resetting it for the acquisition of data from the units A and B.

According to the invention, the optoelectronic device 1 can be equipped with a system 2 consisting of at least three accelerometers operating on three axes X, Y and Z perpendiculars to one another, two of which are arranged horizontally in order to detect the longitudinal and transversal accelerations of the vehicle, while the other axis is arranged vertically to detected to detect the upward and downward accelerations of the vehicle. The signals generated by the block or unit 2 are filtered by a low-pass filter 3 and are finally sent to the processor Z. In combination with the block 2 of the accelerometers, preferably there is used at least one electronic gyroscope 4 and the signals generated by this very accurate electronic compass, through the subsequent block 5 of analogic/digital conversion, are supplied to the processor Z which will be set for processing also the data coming from the blocks 2 Through the blocks 2 and 3 there are acquired at least the date relating to the acceleration of the vehicle along the above indicated three directions, while through the blocks 4 and 5 there is detected the absolute travel direction of the vehicle with respect to the polar axis and it is detected the angular speed during the steering of the vehicle itself. It is to be understood that if the gyroscope block 4 comprises accelerometric devices, these can be in part employed to realise the block 2 or vice versa the accelerometers of this block can be employed to realise block 4.

The data detected by blocks 2 and 4 are acquired by the memory unit of the device for example each millisecond, and since they are digital data they are for example added to the ones supplied by block B of the said known device 1 , provided that this block is available (see after).

In case of an accident, as above said, the device freezes the packages of data relating to the latest instants around the accident itself, for example relating to the latest ten seconds before and five seconds after the accident and this applies also both for the data relating to the real video film, supplied by the micro video cameras A, and for the numerical data supplied by the blocks 2 and 4.

The information relating to the accident contained in the memory block W and/or W1 , are downloaded by means of a suitable interface inside a personal computer and are processed by a dedicated program. While the real filmed sequence will be directly available, it will be possible to process the data from the blocks 2 and 4 in order to obtain a virtual film of the dynamics of the accident, by introducing into the processing model the data relating to the type of involved vehicle, extracted from a suitable library which will specify also the exact location of the device on the vehicle frame. By means of a process of retrospective investigation, starting from the moment of the impact or from the moment of blocking of the memory, the information is acquired going backward inside the same memory, in order to elaborate: a) a bidimensional investigation of the accident; b) a three-dimensional investigation of the same accident; c) an interaction of the methods of investigation. The bidimensional investigation of the accident consists substantially in the elaboration of several graphs combined between them to show for instance the distance covered as a function of time, the paths followed during the time by the vehicle along the three sensible axes of the accelerometers, the distances covered and the relating speeds. A slider can be provided which upon movement onto the graphs suitably aligned and/or superposed, will consent to detect at the same instant the values of the different parameters.

The three-dimensional investigation consists in an animated three-dimensional reconstruction of the accident. It can be of important support to the real filmed sequence, in case of lacking or not clear photograms for the previously mentioned reasons, inasmuch as it supplies an exact information of the path and of the trim of the vehicle, which can be visualised both from the point of view of the driver, and from any point selected in the space outer to the vehicle.

The maximum of information will be available if in the same accident there are involved vehicles provided with the same device of the type under discussion, since the data collected by these can interact between them in the context of a same animated filmed sequence, by utilising the information relating to the recording of the hour and of the absolute direction of travel. The exact instant of the impact, determined by the impact sensor C1 , will be used as point or origin for the necessary synchronisation of the events and in order to compensate for the unavoidable differences of time acquired by the blocks B. The argument concerning the time will be further discussed in the description with an important consideration.

What has been said before applies also in the case of collision of the vehicle with stationary objects having dimensions and shapes which are typical and known. By using the process of retrospective investigation, which consents the reconstruction of the dynamics of the accident backwards in time, by starting from the moment of the collision of the vehicle, it will be possible to locate with precision the position of the object with respect to the vehicle during the whole time of fifteen seconds of recorded data. For this purpose it will be sufficient to insert into the variable of the processing program of the personal computer, the data relating to the object concerned by the collision, data which can be obtained from the above mentioned library and which can relate to typical objects of the route, such as milestones, safety barriers and different typologies of road signs.

Whenever all the vehicles involved in an accident are provided with the device according to the invention, it will be possible to effect further and exact measurement detection "a posteriori".

The interaction of the methods of investigation resides in the fact that all of the three investigations, the bidimensional one and the real video and virtual video, being precision synchronised, can be if required visualised jointly on the same video screen, so that to each one of the photograms of the real video there can be associated the corresponding situation plotted on the bidimensional graphs and the photogram of the virtual animation.

In consideration of the fact that the ratio between the production costs of an optoelectronic device of known type and the costs of the novel portion of the device according to the invention is of about 5 to 1 and in consideration of the fact that the same device according to the invention can be used independently of the known device, by the present patent application it is intended to protect also the device alone for the dynamic detection with a limited number of video, cameras or without these components, according to the diagram of Figure 2. Reference numeral 6 indicates the microprocessor processing unit which is switched on through the ignition key 7 of the vehicle and through a small buffer battery 107, which is useful also for maintaining the stored data in the memories of the unit 6. Reference numerals 2, 3 indicate the block relating to the accelerometers and numerals 4 and 5 indicate the blocks relating to the gyroscope system. The impact sensor which controls the blocking of the operation of the apparatus can be shunted from the system of the accelerometers, upstream of the low-pass filter and at the outlet of a second low-pass filter 103 calibrated at a higher frequency than that of the preceding filter 3.

The device can be advantageously provided with a module 8 of electronic clock, to supply the processor 6 with the information relating to the date and hour, and this module can be for example of the type DCF, radio-controlled, of great precision, so as to realise a safe phase connection between all the devices of the type according to the invention mounted on different vehicles. From the interaction of the modules 8 and 2, 3 it is possible to obtain, by means of known equations, digital information relating to the acceleration and to the speed of travel of the vehicle, even if this latter is not provided with the central unit B according to the previous patent or if it is provided with a central unit which is not apt to furnish digital parameters or parameters which can be easily digitised. By means of the acceleration parameters, it will be also possible to know whether the vehicle is at standstill or in motion, and from the "ground noise" detected by the accelerometers it will be possible to know whether the engine of the said vehicle is running or not.

Reference numeral 9 indicates a preferably extractable memory of digital type, inside which are stored and remain secured the data relating to the accident also when it is extracted from the device. This unit can be advantageously provided with a portion 109 inside which there can be stored a reference code relating to each vehicle and which corresponds for example to the license plate of the vehicle onto which the device is mounted, or to other parameters which identify in a strict manner, so as to avoid the fraudulent substitution of the unit 9 of a device involved in an accident with the unit of another device. When the unit 9 is inserted into the device, for example in the initialisation phase of after an accident, the portion 109 of said unit transfers inside a small memory 106 of the processor 6 the identifying data of the device. If in the installation phase of the memory 9 into a device, the memory 106 is virgin or contains the same data present in the isle 109, the device will automatically set to correct operation as soon as the ignition key 7 of the vehicle is activated. If instead in the memory there are present different data, the device will not be able to operate without the prior intervention onto suitable reset controls arranged at the interior of the device and which are known only to the installers. When, thereafter, the unit 9 is disconnected from the device, it maintains in a frozen condition the detected parameters, including the hour and the date of extraction and the said memory cannot be again qualified for the recording of new data unless after a phase of decoding and of conditioning of said phase, the whole in such a manner as to avoid the substitution of the blocks 9 between devices mounted on different vehicles.

In the isle 109 or other part of the memory 9 there can be registered in a useful manner also a digital code which has the scope of identifying the vehicle according to a table which divides the vehicles by noting their characteristic features, such as for example the mass, the piston displacement and if the case also the typical performances of each vehicle, for example concerning the acceleration. This data is read by the processor 6 upon insertion of the memory card 9 in place, is preferably registered in the memory 106 and is compared with a table present in the software 206 of the said processor and the data 30 resulting therefrom can be used for automatically calibrating the sensibility of the dynamic type detection system 3,103 and/or for modifying the parameters of data processing supplied by said system. It appears evident how this solution consents to manufacture equal devices independently from the vehicles onto which the said devices will be mounted. In order to personalise a device it will be sufficient to condition separately the isle 109 of the memory card 9 designed for each device.

Also the device according to Figure 2 can be provided with a timer 10 which delays for a predetermined time the switching off of the processor 6 after a significant impact, for example for a time which can be greater than five seconds if the device is not provided with optoelectronic sensing devices of the type indicated in Figure 1 (see after). During this time interval there is activated the block 11 of the optical and/or acoustical signallers in order to signal to the user that the processor is going to be shut down. After the predetermined time interval since the significant impact, the processor 6 is shut down and this condition can be signalled by the signallers 11 which for example operate intermittently.

If the impact which caused the intervention of the timer 10 and of the signallers is not due to an accident, to the user there is allowed a time greater than that of recording of the after-event, for example about thirty seconds after the impact, in order to reset the operation of the processor 6, by manual intervention on a button 12 arranged in an easy position. Alternately or in combination with the manual resetting control from the button 12, the processor 6 can be automatically reset if after a suitable time interval from the intervention of the blocks 10 and/or 11, a comparator 13 detects, through the data coming from the blocks 2 and 3, a situation of normality, for example that the vehicle has been kept moving and the engine has not been turned off, or other situations of normality, as indicated after.

In order to certify the reliability of the system, it can be in any case provided that each time that from the blocks 12 or 13 is issued a reset order, said order be recorded in a portion 209 of the memory unit 9 which preserves at least the data relating to the hour and day in which the said reset order has been issued, while the other portion of the memory 9 continues the recording of new data.

According to a different embodiment, the apparatus is not provided with the timer block 10 and the memory 9 con present an isle 309 which is normally free and exclusively reserved for the registration of the after-event data. In case of accident, the memory 9 blocks the data relating for example to ten seconds prior to the accident, while the date of the post-event are commuted into the memory isle 309 which blocks itself when it has been saturated. Upon completion of the saturation of this portion of the memory, the processor 6 is automatically blocked.

With reference to the flow chart of Figure 3 there is now described the possible operation of the apparatus according to Figure 2. Block 14 indicates the origin of an impact which can be significant of an accident. Block 15 relates to the vehicle, with the horizontal outputs which indicate "at standstill" and the vertical output which indicates "in motion". Block 16 relates to the engine of the vehicle, with the horizontal outputs indicating "switched off' and the vertical output which indicates "running". Block 17 finally relates to the parameters which can be derived from blocks 2 and 4, with the horizontal outputs indicating "higher than the standard" and with the vertical output which indicates "within the standard". Block 18 indicates the switch off control of the apparatus and block 19 indicates instead the reset control of the same apparatus. From Figure 3 it is noted for example that in case of significant impact, if the accelerometric parameters are higher than the standard, there takes place the intervention of the block 18 switching off the apparatus. If in case of impact the comparison block 20 detects the fact that the vehicle is at standstill and the engine is switched off, there takes place the intervention of the switch off block 18. If in case of impact the vehicle is stationary, the motor is running and the accelerometric parameters are higher than the standard, there takes place the intervention of the switch off block 18. If in case of impact the vehicle is moving, the motor is running and the accelerometric parameters are higher than the standard, there takes place the intervention of the switch off block 18. If instead after the impact the vehicle is either moving or stationary, the motor is running and the accelerometric parameters are within the standard, there takes place the intervention of the block 17 resetting the apparatus.

It is in any case understood that in order to further improve the operation of the apparatus, the program contained inside the processor 6 can comprise a comparison table of complex situations which could escape the sensibility of the block sensor 103 but which could be significant of accident. For example: an abrupt deceleration followed by an impact lower than the threshold of intervention of the block sensor 103 and by the stop of the vehicle, would constitute a situation which would be ignored by the described system, but which could instead, thanks to a continuous comparison between the collected data and the said table, be interpreted as a possible situation of accident and could be set for activating the same blocking procedure controlled by the sensor 13, which can be subsequently be or not confirmed during the time interval for the automatic or manual reset. The above said comparison table can be from time to time implemented by the data relating to the vehicle contained in the above mentioned memory isle 109.

In consideration of the fact that the greater is the number of elements available for evaluating the dynamics of an accident, the more easy and exact will be the reconstruction of the truth, the apparatus according to Figure 2 can be provided with a single video camera 21 directed towards the interior of the passenger compartment of the vehicle, and intended to be employed as a photocamera, in order to detect the number of the persons occupying the vehicle after each activation of the ignition key 7. The data supplied by this component are of small entity, can be easily compressed and occupy a small memory space, also because they are intended to be periodically cancelled and updated after each start of the vehicle, even with the engine still running, provided that between one start and the successive one there does not take place any significant impact. Reference numeral 22 indicates a microvideocamera with wide angle lens, aimed towards the exterior and forwards, to detect visual data of the possible accident. In this case, when the apparatus detects a significant impact, in the unit of memory 9 there can be stored the events relating to ten seconds before the impact, five seconds after the impact and after these there can be recorded five of more seconds of data coming only from the blocks 2 - 5, since these data occupy a small memory space. In the case that, concurrently with a significant impact, there is be lacking the electric feed from the battery of the vehicle, means will be provided such that, through the buffer battery 107 of the apparatus, there are recorded at least the data of the after event supplied by the accelerometric sensors and by the gyroscope, which require a minimum quantity of energy. The photographic shot taken through the microvideocameras 21 , 22 is obviously coded and can be visualised only by possessing the software of the device.

In order to be able to reconstruct more faithfully and easily the dynamics of an accident, the more so in the case in which the apparatus is not provided with videocameras directed towards the exterior, there can be given the possibility of knowing exactly what was the status of a traffic light at the moment of the accident, through the device illustrated in Figure 4. In this Figure reference numeral 23 indicates the traffic light to which there is preferably connected an optoinsulated interface 24, provided with photodiodes and with photosensors which are activated jointly with the activation of the different relays 123 of the traffic light, a microprocessor electronic unit 25 in its turn connected to a block 26 of a precision clock for example of the type DCF radio controlled, connected or connectable to a display 27 and connected to a digital type memory 28 capable of containing for example the data of at least twenty four hours of operation of the traffic light. The data detected by memory 28 can be usefully implemented with those of the memory 9 of the device of Figure 2, so as to obtain in the bidimensional of three-dimensional reconstruction of the accident also the progressive modifications of status of the traffic light near to the accident itself.

Claims

1. An electronic device to be installed aboard land vehicles and/or boats for obtaining information particularly useful in case of accident, comprising and electronic unit (6) which can be activated or de-activated by the ignition key (7) of the said vehicles or boats, which can be de-activated by an impact sensor and is interacting with a continuous operation digital type electronic memory unit (9) adapted to record information useful in case of accident and generated by suitable sensors, characterised by the fact that said sensors consist of accelerometric devices (2) arranged in a predetermined location of the vehicle and which through at least a subsequent low-pass filter (3) supply very exact kinematic information about the vehicle itself, which can be collected and recorded at very high frequencies, up to the order of a millisecond.

2. A device according to claim 1 , in which the accelerometric sensor consists of at least three accelerometers the axes of sensibility (X, Y, Z) of which are perpendicular to one another, two of said axes being horizontal and oriented the first one in the direction of the length and the second one in the direction of the width of the vehicle, while the other axis is vertical, so as to obtain the information of the accelerations in the above mentioned three directions and the inclination of the vehicle on the vertical axis, in addition to the information which can be derived therefrom and relating for example to the fact that the vehicle is at standstill or in motion and the engine is running or switched off.

3. A device according to claim 1 , characterised by the fact that the output of the accelerometric sensor (2) is filtered by a second low-pass filter (103) calibrated at a calibration higher than the calibration of the first filter (3) which supplies the kinematic parameters to be recorded, the output of said second filter being used as impact sensor in order to control the de-activation cycle of the electronic unit (6) to retain in the memory the data recorded in concurrence with an accident.

4. A device according to claim 1 , characterised by comprising also a system of gyroscopes (4) provided if required with an analogic digital conversion block (5), to detect at least the absolute direction of travel of the vehicle with respect to the polar axis and to detect also the angular speed during the steering of the vehicle and/or other parameters.

5. A device according to claim 4, characterised by the fact that if the system of gyroscopes comprises accelerometric devices, these can be employed to form the unit (2) of the accelerometric sensors or vice versa, the accelerometers of said unit can be employed to realise the gyroscopes.

6. A device according to claim 1 , characterised by the fact that the microprocessors electronic unit (6) interacts with an electronic clock module (8), for example of the DCF type, radio controlled, which consents to obtain a safe phasing between several devices according to the invention mounted of different vehicles and which can be used by said processor to obtain by interpolation with the signals coming from the accelerometric sensors (2), the data relating to the travel speed of the vehicle.

7. A device according to claim 1 , in which the memory unit (9) preferably of the extractable type, is set for an autonomous operation in order to preserve the recorded data, and it is pre-arranged so as to record, in an isle (109) of its own, a code of identification which links it in a safe manner to the vehicle onto which the said device is to be mounted, and corresponding for example to the number of the license place of the vehicle.

8. A device according to claim 7, in which the microprocessor electronic unit (6) is provided with an inner memory (106) inside which there is recorded the contents of the portion (109) of the extractable memory (9) relating to the identifying code and which is maintained also in case of extraction of the said memory, unless there is made an intervention onto suitable resetting means which are internal to the said device, the whole in order to avoid fraudulent substitutions of the memories (9) between different devices and to recycle the said devices.

9. A device according to claim 7, in which the memory unit (9) is arranged to record, in a suitable isle (9) a digital code having the scope of identifying the vehicle for which the memory is intended, according to a table which divides the vehicles according to their characteristic features, such as for example the mass, the piston displacement and the acceleration performance, in the processor (6) there being provided means for obtaining the above mentioned data and for comparing it with a table which is present in the software (206) of the said processor and means being provided to employ the data resulting from this comparison, in order to automatically calibrate the sensibility of the dynamic type detection system (2, 3, 103) and/or to modify the parameters for processing the data supplied by said system.

10. A device according to claim 1 , characterised by being provided with a timer (10) which intervenes after that the impact sensor (103) has evidenced a possible situation of accident, in order to delay the de-activation of the processor (6) and to consent the recording of the date in the memory unit (9), for a predetermined time after the intervention of the said impact sensor, so that inside said memory unit there are recorded the data preceding and also subsequent to the same accident.

11. A device according to claim 1 , characterised by the fact of comprising commutation means which concurrently with the detection of a significant impact, deviate the recording of the after event data into an isle (309) purposely dedicated in the memory (9).

12. A device according to claim 1 , characterised by comprising means (13) which after the intervention of the impact sensor (103) are activated in order to verify possible normality situations of the vehicle, of the engine of the vehicle and of the accelerometric parameters and which in case of normality provide for the automatic resetting of the processor (6) in order to prevent the command of block generated by the said impact sensor (103).

13. A device according to claim 1 , characterised by the fact that the software (206) of the processor (6) can comprise a comparison table of complex situations which might escape to the sensibility of the impact sensor (103) but which could be significant of an accident, there being provided in the same processor means for comparing the accelerometric data of this table and for generating, in case of positive comparison an situation of alarm analogous to the one subsequent to the intervention of the said impact sensor, with the blocking of the data relating to the event and starting of the registration of the data of the after event.

14. A device according to claim 1 , characterised by comprising optical and/or acoustic signallers (11) which intervene concurrently with the activation of the impact sensor (103) to inform the user that the processor (6) is going to be blocked.

15. A device according to claim 14, in which the signallers (11 ) are arranged so as to remain active but to modify their operation, for example to switch from a continuous operation to an intermittent operation after the phase of blocking of the processor (6), by staying in said condition for a time interval which is sufficiently ample, for example about thirty seconds.

16. A device according to claim 4, characterised by the fact that a button (12) is provided in an easy position to be acted upon by the user, for the manual resetting of the processor (6) in the time interval during which the signallers (11 ) operate intermittently.

17. A device according to claim 7, characterised by comprising in the extractable memory (9) a zone (209) reserved to the recording of the date and hour in which the processor (6) received any manual or automatic reset order.

18. A device according to claim 1 , characterised by comprising a microvideocamera (21) directed towards the interior of the passenger compartment of the vehicle and arranged to operate as a digital photocamera in order to detect, at each start of the vehicle and to record into the memory unit (9) the data relating to the persons occupying the vehicle,

19. A device according to claim 18,characterised by comprising means for compressing the data detected by the digital photocamera (21) and for updating same with elimination of the preceding data, each time that the vehicle starts, and if between one starting and the subsequent one, there is not intervened the impact sensor (103).

20. A device according to claim 3, characterised by comprising at least one microvideocamera (22) with a wide angle lens, oriented forwards and toward the exterior in order to detect what is substantially visible from the driver of the vehicle, the data of said component being recorded in closed circuit inside the said memory unit (9) and in case of accident being preserved inside said unit with the same logic of the data coming from the accelerometers (2) and from the gyroscope or gyroscopes (4).

21. A device according to claim 20, characterised by comprising means such that, in the presence of data recorded coming from the microvideocamera (22) the recording times for the after event are limited for the said data, while they can be lengthened for the data supplied by the accelerometers (2) and the gyroscopes (4).

22. A device according to claim 21 characterised by comprising such means that in case of lack of electric energy from the battery of the vehicle, concurrently with a significant impact, at least the after event data generated by the accelerometers (2) and by the gyroscopes (4) are recorded.

23. A device according to claim 21 , in which means are provided so that the images recorded in the memory (9) from the optoelectronic sensors (21 , 22) are coded and can be decoded only with the accessibility to the software of the device according to the invention.

24. A device according to claim 7, characterised by the fact that the decoded data from the extractable memory (9) particularly if the device is not provided with optoelectronic sensors (22), can be implemented with the data obtained from the traffic lights which control the traffic, in order to detect their status at the moment in which in proximity thereof there took place the accident, each traffic light (23) being for this purpose provided with an optoinsulated interface (24) connected to a microprocessor (25) interacting with a precision clock (26) for example of the DCF type, radio controlled, and a display (27) and a suitable digital memory (28).

25. A device according to claim 7, characterised by comprising means for decoding the data recorded inside the extractable memory (9) in order to realise a bidimensional investigation of the accident, which consists into the elaboration backwards in time, of graphs suitably combined with them to show for example the distance covered by the vehicle during the time, the paths followed by the vehicle during the time along the three axes of sensibility of the accelerometers (2), the covered distances, the relating speeds, as well as the status of the vehicle, whether at standstill or in motion, and the status of the engine, if running or switched off, and possibly there being provided a movable slider in order to evidence the entity of the various parameters for example during the unity of time.

26. A device according to claim 7, characterised by comprising means for decoding the data recorded inside the extractable memory (9) to realise a three- dimensional investigation, real and/or virtual, of the accident, means being provided so that the virtual investigation can be reconstructed from the point of view of the driver, or from any other point in space, even outer to the vehicle.

27. A device according to claim 26, characterised by comprising decoding means which can be implemented by data taken from a suitable library and relating to the type of vehicle involved in the accident and/or to known objects normally placed along the road, such as poles of traffic lights, of road signs, milestones, kerbstones, to consent an exact three-dimensional reconstruction of the event also in case the vehicle has collided against such objects.

28. A device according to claim 1 , characterised by comprising decoding means which consent an interaction of the investigation methods and which consent to visualise in synchronism onto a same video screen the various phases of the bidimensional investigation and of the video investigations real and/or virtual.

29. A device according to claim 1 , characterised by comprising means for implementing and comparing the data taken from different devices according to the invention, mounted on different vehicles and involved in a same accident.