CA2077596A1

CA2077596A1 - Vehicle safety device

Info

Publication number: CA2077596A1
Application number: CA002077596A
Authority: CA
Inventors: Michel Nault
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-09-04
Filing date: 1992-09-04
Publication date: 1994-03-05

Abstract

ABSTRACT

A vehicle safety system includes a plurality of Infrared (IR) motion sensors which produce an output signal upon detection of a person within their range and a vehicle brake application arrangement for disablement of the vehicle upon receipt of the output signal. The system is activated by a vehicle door controlled switch. The vehicle door is maintained in the opened condition by a door locking arrangement to prevent deactivation of the system while a person is detected. The system further includes a timed switch which maintains the system activated for a preselected time interval after closing of the door. The system substantially prevents collisions due to driver error between the vehicle and persons discharged therefrom and is of simple construction.

Description

Vehicle SafetY Device Field of the Invention The invention relates to accident prevention systems for vehicles and in particular to safety devices for the prevention of collisions between vehicles and pedestrians.

B~ckv.round of the I~vention A large number of pedestrians are Xilled every year in collisions with vehicles. Such accidents are especially tragic when the person in~ured or killed is a child who only moments earlier stepped off the accident vehicle, e.g. a school bus. Although school buses are equipped with large parabolic mirrors which assist the driver in monitoring the environment of the school bus, some regions close to the bus and all the area under the bus cannot be seen by the driver. Furthermore, even a momentary lapse of observation by the driver can result in fatal in~ury.
In fact, a distressingly large number of school bus accidents are caused by driver error. In an effort to overcome these problems, school buses have been equipped with mechanical arms, which are extendible from the front end of the bus to force those children which pass in front of the bus to walk where the driver can actually see them without the aid of mirrors. However, mechanical problems associated with these arms, such ;~ as sei~ing in the extended or retracted condition, especially in winter, have prevented their wide-spread introduction. Furthermore, the driver must still maintain constant vigilance during entry and exit of passengers and accidents due to driver error cannot be prevented.
Parent organizations and the general public are therefore pressuring the transport ministries and school boards to equip school buses with an effective safety ~ystem which sub~tantially reduces, if not eliminates, these types of accidents and operates without driver intervention.
~ utomatic surveillance and accident prevention systems are known from Canadian Patent 1,237,798 by Dombrowski and U.S. Patent 4,779,095 by Guerreri. Dombrowski discloses a driver alerting device for the -detection of an ob~ect beneath, forwardly of and to the passenger discharging side of a school bus. The device operates on the doppler shift principle and includes micro-wave radar transceivers and an , :

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electronic circuit which activates an audible alarm when a doppler shift i9 detected between the transmitted signals and any reflected signals.
Although the ~ystem may be used to detect ob~ects which are moving relative to the bus, relatively stationary ob~ects or persons cannot be detected, since stationary ob~ects do not cause a doppler 9hift. Thus, a child which fell in front of the bus and lies unconscious out of view of the driver could not be detected, which could result in serious in~ury to tho child. Also, moving ob~ects which are close to but not in a dangerous area around the bus may triBger false alarms, which could lead to the driver ignoring the alarm when no child is visible in the close vlclnity of the bus. Finally, the microwave radar transmitters, antennas and analysis circuitry required make the system an expensive and, thus, uneconomical solution.
Guerreri (U.S. Patent 4,779,095) describes an image change detection Aystem for the automatic monitoring of a region beneath and around a school bus. The system compares a stored base line ima8e of the environment to one or more subsequent images to detect differenc~s therebetween. The images are divided into a number of pixels and deviations between images are detected by matching the pixels of a subsequent image with the pixels of the first image. If a preselected pixel deviation thre~hold is exceeded, an audible or vi~ible alarm is sounded or the vehicle is disabled by the system. Each pixel corresponds to one photodiode of a monolithic photodiode array. Although this system should be able to detect an unconscious child, it will also detect other moving or stationary ob~ects which appear in the survellled region after the base line image was stored, such as leaves, rocks, pieces of paper etc. Thus, this system requires read~ustment of the deviation threshold to different environmental parameters, in order to avoid false alarms.
In addition, the system includes Qophis~icated electronic circuits and components which results in high manufacturing cost and makes this system uneconomical.
Thusj a safety system for vehicles is desired which is of a simple construction, is economically manufactured, and reliably detects the presence of a moving or stationary person in the vicinity of the vehicle.
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Swmmarv Of The Invention It is an ob~ect of the invention to provide an automatic vehicle safety device for the detection of a person in a selected surveillance ~rea close to or under the vehicle, which device i9 of simple construction and may be manufactured and installed at relatively low cost.
~ t is another ob~ect of the invention to provide a vehicle safety d~vlce which will detect both a moving and a stationary person in the surveillance area.
It is a further ob~ect of the invention to provide a vehicle safety device, which is of simple construction and will automatically disable the vehicle without intervention by the driver when a person is detected in the surveillance area.
Accordingly, the invention now provides a vehicle safety device including an infrared (IR) motion sensing means for detecting the presence of a per~on in a selected surveillance zone ad~acent the veh~cle, the sensing means producing an output signal upon detection of a person, and a stopping means connected to the sensing means for ;~ automatically disabling the vehicle upon receipt of the output signal.
The IR motion sensing means preferably includes an IR motion sensor fastened to a mounting surface of the vehicle and means for swaying the motion sensor relatlve to the mounting surface to such an extent that a motionless person located in the surveillance area is detectable by the ; motion sensor.
The vehicle safety device preferably further includes a control ; 25 means for maintainin8 the safety device act~vated for a selected time interval after closing the vehicle door. The safety device may be activated by way of a door switch and may further include a door locking mean~ for maintaining the ~ehicle door open to prevent deactivation of ` the safety device while a person i9 detected. The sensing means j~ 30 preferably includes a plurality of IR motion sensors positioned about the vehicle 90 that the combined surveillance area~ of the sensors completely cover the selected surveillance zone around and under the vehicle.
In a preferred embodiment, the sensing means is an IR motion detector positioned at a central location in the vehicle and the system further includes fiber optic means for transmitting IR radiation emitted within the surveillance zone to the IR motion sensor. The stopping means ~ - , : .: . . , , , . . . . ~:,. : . : : . -. . :

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is preferably a brake actuating means for relea~ably applying a bra~e of the vehicle.

DescriDtion Of The Preferred Embodiment Preferred embodiments of the invention will now be further described by way of example only and with reference to the following drawings, whcrein Figure 1 ls a schematic diagram of a preferred embodiment of a vehicle saety system in accordance with the invention;
Figure 2 is a schematic diagram of another embodiment of a vehicle safety system in accordance with the invention;
Figure 3 illustrates the brake actuating arrangement used in the embodiments shown ln Figures 1 and 2;
Figure 4 indicates the preferred locations of the IR motion sensors, when the vehicle safety device is installed in a school bus;
Figure 5 shows the swaying arrangement for the sensors; and Flgure 6 schematically illustrates a portion of another embodiment having one central IR motion sensor and several radiation transmitting fiber optic cables.
The preferred embodiment of a vehicle safety system in accordance with the invention illustrated in Figure 1, is preferably installed in a school bus in a manner described further below and includes a number of IR motion sensors 10 (only one shown for reasons of clarity) for the detection of a person within the range of the sensor(s), and a stopping arrangement 20 for the disabling of the vehicle when a person-30 is detected by the sensor.
IR motion sensors generally go through a ~elf-testing program after they are switched on. This program can run from 20 to 60 seconds during whlch time the sensors cannot be used for their intended purpose.
Therefore, in this embodiment, each sensor 10 is continuously supplied with operating voltage either directly from the vehicle battery or from the ignition switch of the vehicle. The remainder of the device is activated by a door switch 40 which in the open position of the door supplies positive operating voltage to one of the normally open contacts 64 of a control relay 60 through a conductor 140. The other of contacts 64 is connected to the stopping arrangement 20 through a conductor 142.

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The stopping arrangement 20 includes a pneumatlc brake pedal operating cylinder 22, the operation of which will be discussed in detail further below with reference to Figure 3, a pressurized air storage tank 24 and a ~olenoid 26. Solenoid 26 controls the supply of pressurized air from ~torage tank a4 to the brake pedal operating cylinder 22 and a plunger coil 27 of the ~olenoid is connected to conductor 142. Sen~or 10 inc~udo~ a pyroelectric detector 12 and a signal processing unit 14 which produces an output ~ignal when the overall IR radiation emitted within the range of the sensor has changed. The sensors used in this embodiment are Paradox Avantage (Pirotech, Quebec, Canada) or SafeHouse ~InterTan, Canada), but other commercially available infrared motion detectors may be used as well. A conductor 144 connects the output of the sensor 10 with a driver alerting display 50, which is mounted within view of the driver, for example in the dashboard of the school bus. Display 50 includes a schematic diagram 52 of the bus and has a light emitting diode ~LED) 54 for each sensor 10 mounted to the bus, which LEDs are respectively connected to the conductors 144 of the indivldual sensors.
- A conductor 146 connects a ~unction 147 on conductor 144 with a switching coil 62 of the relay 60. The safety system further includes a door locking arrangement 42 which will lock the bus door in the opened position when a person is detected in the surveillance area around the bus 90 that the driver cannot disable the system and drive away while it is not safe to do 90. This will substantially avoid accidents caused by driver error and provides added safety for discharged passengers still close to the bus. Any arrangement may be used which is operably linked - to the sensor 10, the relay 60 or the stopping arrangement 20 to lock the bus door in the opened position when a person i3 detected. However, in this embodiment, the door locking arrangement i9 a pneumatic cylinder 44 which is supplied with pressurized air from the tank 24 through a tubing 30 126. The air supply to cylinder 44 is also controlled by solenoid 26.
The pneumatic cylinder 44 is affixed overhead to the door frame 46 and the door 48 respectively, but may also be connected to the door opening ~;
mechanism operated by the driver (not shown).
In operation, the driver opens the vehicle door (not shown) after ~5 having stopped the vehicle, wh~reby door switch 40 is closed. When now a person walkQ through the range of sensor 10, signal processing unit 14 .
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produces an output signal which is transmitted through conductor 144 to the associate LED 42 of display 50. Thus, the location of the person detected relative to the bus will be apparent from the display.
Furthermore, the output signal is transmitted through conductor 146 to ~witching coil 62 which flips relay 60 thereby closing contscts 64 90 thAt operating power i9 supplied to the plunger coil 27 of solenoid 26.
The ~lunger coil 27 produces a magnetic force which moves the plunger ~not shown) of the solenoid 26 to a position where the brake pedal operating cylinder 22 is supplied with pressurized air from tank 24 through tubing 120 and 122. A brake pedal 70 of the bus is depressed by the retraction of cylinder 22, which locks the brakes of the bus (not shown). Stopping arrangement 20 is activated and the brakes of the bus remain applied as long as a person is detected by one of the sensors 10.
Pressurized air from tank 24 i9 supplied simultaneously to the brake - 15 pedal operating cylinder 22 and to the door locking cylinder 44.
- Cylinder 44 extends and locks the door in the opened position, 90 that the safety device cannot be deactivated by the driver as long as a person ; i9 detected by ane of the sensors. Thus, the bus i9 reliably disabledand bus/passenger collisions are substantially prevented when the safety system i9 activated and a person i9 within the range of any one of the sensors 10. The stopping arrangement 20 may also include a pneumatic accelerator pedal locking cylinder 28 which is supplied with pressurized air from tank 24 through tubing 122. Thus, when the stopping arran8ement 20 i9 activated, cylinder 28 is extended and locks the accelerator pedal in the idle position.
The safety system illustrated schematically in Figure 2 includes the same basic components as the system discussed above, namely at least one IR motion sensor 10, a stopping arrangement 20, a door switch 40, a door locking arrangement 42 and a driver alerting display 50. The construction and function of these components i9 as di~cussed above in relation to Figure 1. The system further includes a timed switch 80, which keeps the system activated for a selected time internal (10-15s) - after the bus door has been closed. The control input of timed switch 80 is connected through conductor 140 to the door switch 40. The power input and output of the timed switch 80 are respectively connected to the :.... ' : . ' . , ' ,. , ;:

positive power source (battery or ignition switch) of the bus and through a conductor 150 to one of ~he contacts 64 of relay 60.
During operation, the opening of the bus door closes door switch 40, whlch provides operating voltage to timed switch 80. The timed switch 80 closes and in turn connects the contact 64 with the vehicle power ~u~ply. When a person is detected by sensors 10, an output ~ignal is produced and transmitted through conductors 144, 146 to the switching coil 62 of relay 60, which flips relay 60 to the activated condition wh~rein positive voltage is supplied thr~ugh the conductor 142 to the stopping arrangement 20 as in the embodiment shown in Figure 1. Thus, the brakes are applied and the door is locked in the opened po~tion while a person is detected by sensor 10. When no persons are detected by the sensor 10 and the driver closes the door 48, the timed switch 80 provides power to one of the contacts 64 for a preselected time interval (10-15 seconds) so that the bus will be automatically stopped should a child come running back to the bus which has led to serious accidents in the past when a child forgot something in the bus and ran back to get it. This substantially reduces the risk of a child having left the range of the sensors being hit when running back to the bus.
Turning now to Figure 3, a brake pedal 162 is pivotally connected at a first pivot 163 to a main brake cylinder operating rod 164. Main brake cylinder 165 is affixed to a fire wall 166 of the vehicle. Pneumatic brake pedal operating cylinder 22 is also affixed to the firewall 166 and is connected to a second pivot 167 on the brake pedal 162 by a cylinder rod 168, which includes a pivot receiving elongated eyelet 169. Thus, the brake pedal 162 can be depressed by the driver of the vehicle when the cylinder 22 is in the extended position whereby the second pivot 167 slides longitudinally in the eyelet 169. On the other hand, w~en cylinder 22 is supplied with pressurized air from tank 24, (see ~ig. ~ or 2) through air supply tube 122, the cylinder rod 168 is retracted which results in the brake pedal being depressed and the brakes being applied.
When cylinder 22 is no longer supplied with pressurized air, a resetting spring (not shown) mounted on the braXe pedal p~vot 171 returns the brake pedal 162 to the undepressed posi~ion whereby the cylinder rod 168 of ` 35 cylinder 22 is again in the extended position.

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Figure 4 shows the preferred location~ of the sensors 10 on a school bus 100. The sensors are positioned so that their ranges overlap and that their combined ranges form a continuous surveillance zone around and under the bus.
Fl~ure 5 lllu~trates the swaying arrangement used to moderately sway th~ ~ensor~ 10 5 to 15 around a pivot 170 mounted to the school bus 100 ~sce Figure 4). The actual degree of swaying required for the sensor 10 to de~ect ~n unconscious person depends on the model of IR sensor used, but can be readily selected by the art skilled person. Each sensor 10 i8 individually mounted on a base plate 173 which includes a mount 174 having a bore 176 for receiving the pivot 170. An automatically reciprocating pneumatic cylinder 178 is attached to an edge of the base plate 172 by a ball and socket arrangement 180 whereby the ball 182 is affixed to a cylinder shaft 184 and the socket 186 is affixed to the base plate 172. Cylinder 178 iq supplied with pressurized air from the tank 24 ~see Figures 1 and 2) through air supply lines 188 and 189.
Turning now to Figure 6, a safety device in accordance with the invention may include only one sensor 10 which is installed in the vehicle at a central location. Infrared radiation from within a selected - 20 surveillance area around and under the vehicle is transmitted to thesensor 10 by fiber optic cables 192. In this embodiments, a first lens lg4 ls positioncd at each of the locations on the vehicle where a sensor 10 would be installed if the embodiments of Figure 1 or 2 were used. The first lens 194 focuses the IR radiation emitted within the surveillance area corresponding to the range of a sensor 10 installed at the same location onto an end of one of the fiber optic cables. A second lens 196 is placed in front of the sensor 10, which lens focuses all radiation transmitted by all cables 192 onto the pyroelectric detector 12 of the sensor. Thus, all IR radiation emitted in the combined surveillance areas of all lenses 194 is transmitted to the sentral sensor.
Alternatively, two sensors (not shown) may be used which by way of a mirror arrangement are both supplied with radiation from the surveillance zone so that the device wilI still function should one of the sensors fail. Each lens 194 may be mounted on a base plate 172 of a swaying arrangement as shown in Figure 5 to permit detection of a stationary person located in the surveillance area around the bus.

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g In the embodiments shown in Figure 1 and 2, the door switch 40 may also be used to ~upply operating power directly to the plunger coil 27 of solenoid 26 while the door is open. This wlll prevent creeping of the bus whlle the door is open, which has also led to accidents in the past.
Although the construction and mounting oP the braXe pedal operating cylinder 22 shown in Figure 3 is preferred) the cylinder 22 may extend when ~u~plied with pressuriæed air and may be mounted not to the firewall but connected, for example, to the steering column of the vehicle or any other easily acce~sible structural element of the vehicle close to the braXe pedal.
It will be readily apparent that the stopping arrangement 20 may also function hydraulically when the operating fluid i8 a liquid.
Furthermore, the pressurized operating fluld may be obtained from a hydraulic or pneumatic system already installed in the vehicle. In the alternative, the tanX 24 may be filled with pressuri~ed fluid by way of an appropriate compressor or pump driven by the vehicle's engine or operated independently therefrom.
Changes and modifications in the specifically described embodiments can be carried out without departing from the scope of the invention which is intended to be limited only by the scope of the appended claims.

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Claims

EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE
IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A vehicle safety device, comprising an infrared (IR) motion sensing means for detecting the presence of a person in a selected surveillance zone adjacent the vehicle, the sensing means producing an output signal upon detection of a person; and a stopping means connected to the sensing means for automatically disabling the vehicle upon receipt of the output signal.

2. A vehicle safety device, comprising an IR motion sensing means for detecting the presence of a moving or stationary person in a selected surveillance zone adjacent the vehicle, the motion sensing means including an IR motion sensor fastened to a mounting surface of the vehicle and means for swaying the motion sensor relative to the mounting surface to such an extent that a motionless person located in the surveillance area is detectable by the motion sensor, the sensing means producing an output signal upon detection of a person in the surveillance area; and a stopping means connected to the sensing means for automatically disabling the vehicle upon receipt of the output signal.

3. A vehicle safety device as defined in claim 1 or 2, wherein the vehicle is a school bus.

4. A vehicle safety device as defined in claim 4, wherein the vehicle has a door and the device further includes a vehicle door controlled switch means for activating the safety device upon opening of the vehicle door

5. A vehicle safety device as defined in claim 4, further including a door locking means for locking the vehicle door in an open position when a person in detected by the sensing means thereby preventing deactivation of the system while a person is detected.

6. A vehicle safety device as defined in claim 5, the system further including a control means for maintaining the safety device activated for a selected time interval after closing of the vehicle door.

7. A vehicle safety device as defined in claim 1, 2, 4, 5 or 6 wherein the sensing means includes a plurality of infrared (IR) motion sensors, each sensor having a predetermined range and the sensors being positioned about the vehicle so that the combined ranges of the sensors completely cover the selected surveillance zone around and under the vehicle.

8. A vehicle safety device as defined in claim 1, 2, 4, 5, or 6 wherein the sensing means is positioned at a central location in the vehicle and the device further includes fiber optic means for transmitting infrared radiation emitted within the surveillance zone to the IR sensing means.

9. A vehicle safety device as defined in claim 1, 2, 4, 5 or 6 wherein the vehicle has a vehicle brake and the stopping means is a brake actuating means for releasably applying the brake of the vehicle.

10. A vehicle safety device as defined in claim 9, wherein the vehicle has a brake pedal for operating the vehicle brake and the brake actuating means includes means for releasably depressing the brake pedal of the vehicle.

11. A vehicle safety device as defined in claim 10, wherein the brake actuating means includes a first fluid operated linear drive means for depressing the brake pedal, a pressurized fluid storage, a first conduit means for supplying pressurized fluid from the pressurized fluid storage to the first linear drive means and fluid control means for selectively interrupting the supply of pressurized fluid to the linear drive means through the first conduit means.

12. A vehicle safety device as defined in claim 11, wherein the pressurized fluid is one of gas and liquid.

13. A vehicle safety device as defined in claim 12, wherein the pressurized fluid air, the linear drive means is a pneumatic cylinder, connected at respective ends to a structural element of the vehicle and to a pivot on the brake pedal and the control means is a solenoid.

14. A vehicle safety device as defined in claim 5, wherein the door locking means includes a second fluid operated linear drive means for maintaining the vehicle door in the opened position.

15. A vehicle safety device for a vehicle having a door and a vehicle brake and brake pedal, comprising:
a plurality of infrared (IR) motion sensors for detecting the presence of a person in a preselected surveillance zone adjacent the vehicle at least one of the motion sensors producing an output signal when a person is detected in the surveillance zone;
a brake actuating means connected to the motion sensors for releasably applying the brake of the vehicle upon receipt of the output signal;
a vehicle door controlled switch means for activating the safety device upon opening of the vehicle door;
a door locking arrangement for maintaining the vehicle door in an opened condition when a person is detected by the sensing means to prevent deactivation of the system while a person is detected; and control means for maintaining the safety device activated for a selected time interval after closing of the vehicle door;
each of the motion sensors having a predetermined range and the motion sensors being positioned about the vehicle so that the combined ranges of the sensors completely cover the selected surveillance zone around and under the vehicle.

16. A vehicle safety device as defined in claim 15, wherein the brake actuating means includes first fluid operated linear drive means for operating the brake pedal, a pressurized fluid storage, first conduit means for supplying pressurized fluid from the pressurized fluid storage to the linear drive means and fluid control means for selectively interrupting the supply of pressurized fluid to the linear drive means when the output signal is received by the brake actuating means; and the door locking arrangement includes a second fluid operated linear drive means for maintaining the vehicle door in an opened condition and a second conduit means connected to the first conduit means for supplying pressurized fluid from the fluid storage to the second linear drive means, the control means selectively interrupting the supply of pressurized fluid to both the first and second linear drive means, for maintaining the vehicle door in an opened condition while the safety device is activated and a person is detected by the sensing means.

17. A vehicle safety device as defined in claim 16, wherein the pressurized fluid is compressed air and the first and second linear drive means are pneumatic cylinders.