SYSTEME D'EVITEMENT DES COLLISIONS AU MOYEN D'IDENTIFICATION PAR RADIOFREQUENCE

COLLISION AVOIDANCE AND RFID SYSTEM

Abrégé anglais

A system comprised of radio frequency transceivers mounted on vehicles and
humans whereby the transceivers detect one another and warn the wearer or
vehicle operator of a possible collision. Fixed hazards such as open holes can

have a portable transceiver setup nearby to warn personnel of the hazard. The
range at which the hazards are detected and warnings issued are programmable.
A
zone in around the operator area of a vehicle can be set up in which the
operator's
tag and the vehicle's tag ignore one another. Special transceivers can be set
up as
'readers' and would collect unit ID's as they passed within the set range and
the
information passed on to a central processor.

Revendications

CLAIMS


1. A collision avoidance and RFID system comprising devices attached to
vehicles and or people and or fixed locations to detect other devices of
the same nature in proximity by way of received radio frequency (RF)
signal strength.

2. A collision avoidance system as defined in claim 1, including devices
comprising a means of RF transmission and reception, a means of
measuring received RF levels, a means of dynamically controlling said
means of transmission and reception, a means of dynamically setting
one or more RF thresholds, a means of comparing measured RF
levels to said thresholds and a means of indicating a possible collision
to a user.

3. A collision avoidance system as defined in claim 2 further comprising
one or more detection zones around a device defined by RF thresholds
whereby a received message from another device whose RF level
exceeds the threshold would constitute a possible collision.

4. A collision avoidance system as defined in claim 3 further comprising a
message protocol that includes sending a device unique identifier (ID)
with each transmission.

5. A collision avoidance system as defined in claim 4, including any
number of sub-type classifications of devices.

6. A collision avoidance system as defined in claim 5 further comprising a
means of assigning specific a RF threshold or detection zone to each
sub-type classification of devices.



7. A collision avoidance system as defined in claim 6 further comprising
of a means of disabling a user-worn device when in very close
proximity to a vehicle mounted device whereby preventing constant
possible collision detections between a driver or passenger equipped
with a user-worn device and the vehicle mounted device.

8. A collision avoidance system as defined in claim 7 including a second
RF threshold for a sub-type in close proximity to a user-worn device
that, if exceeded, would trigger a disabling function in the user-worn
device.

9. A collision avoidance system as defined in claim 7 including a user
operated switch that would trigger a disabling function in a user-worn
device.

10. A collision avoidance system as defined in claim 7 including a second
RF threshold in a vehicle mounted device for a user-worn sub-type in
close proximity to the vehicle that if exceed would trigger the
transmission of a "disable" message to the specific ID that exceeded
the threshold.

11. A collision avoidance system as defined in claim 5 further comprising a
means of using the ID's and sub-types classifications of received
messages to determine the number of devices of each sub-type within
the detection zone(s) of a device.

12. A collision avoidance system as defined in claim 11, including a means
of indicating a possible collision consisting of a single warning light or a
series of lights representing different sub-types.



13. A collision avoidance system as defined in claim 12 further comprising
using the warning light(s) to convey the detection of different numbers
of devices by leaving them on or flashing at a set rate or rates.

14. A collision avoidance system as defined in claim 11, including a means
of indicating a possible collision consisting of a single audible alarm or
a number of unique alarms representing different device sub-types.

15. A collision avoidance system as defined in claim 11, including a means
of indicating a possible collision consisting of a vibrator motor.

16. A collision avoidance system as defined in claim 2, using a multiple
access protocol to prevent multiple devices in the system from
transmitting at the same time.

17. A collision avoidance system as defined in claim 16, in which devices
transmit messages including their sub-type and ID on a common
frequency as to allow receiving units to identify the type of hazard in
the area.

18. A collision avoidance system as defined in claim 17 further comprising
a communications protocol whereby devices transmit n times per
second on frequency A and spend the remainder of the time in receive
mode on frequency A listening for other devices in the system.

19. A collision avoidance system as defined in claim 16, in which devices
of different sub-types transmit messages on frequency A to frequency
n, with n being the number of device sub-types in the system, to allow
receiving units to identify the type of hazard in the area.



20. A collision avoidance system as defined in claim 19 further comprising
a communications protocol whereby devices transmit n times per
second on the frequency assigned to their sub-type and spend the
remainder of the time in receive mode scanning through frequencies
A...n listening for other devices in the system.

21. A collision avoidance system as defined in claim 10 including a device
sub-type that are mounted in fixed locations that constantly monitor the
system's frequency or frequencies and collect the ID's of any devices
that transmit messages exceeding the stationary devices' RF
threshold.
22. A collision avoidance system as defined in claim 21 further comprising
a means time-stamping the ID's as they are received.

23.A collision avoidance system as defined in claim 22 further comprising
a means of transporting the time-stamped ID's along with the
stationary devices' ID from a plurality of stationary devices to a central
computer for the purpose of personnel and vehicle tracking.

Description

CA 02549870 2006-06-06

Collision Avoidance and RFID System
System Overview

- Two functions performed with one system; Collision Avoidance and RFID
(radio frequency identification)
- Common hardware: radio transceiver
- Collision avoidance and RFID performed with same messages
- Stand alone system that requires no external communication infrastructure.
Collision Avoidance

Purpose:
To aid in the prevention of collisions between vehicles and other
vehicles/machinery as well as between vehicles and humans. These
incidents commonly occur in an industrial situation where large vehicles
with limited operator visibility are used.

How it works:
- Each vehicle and person is equipped with a Collision Avoidance / RFID
transceiver or 'tag'.
- The tags detect one another using received signal strength (RSSI).
- Tags listen most of the time but transmit their message several times per
second using an anti message collision protocol such as carrier sense multiple
access (CSMA).
- The messages contain codes identifying the type of equipment as well as a
unique ID.


CA 02549870 2006-06-06

- If the received signal strength is higher than the programmed threshold then
the remote tag is considered a hazard and the local tag listens for the remote
tag's message.
- Visual andlor audible warnings are given in the event of a possible
collision.
- Different warnings are given for different types of hazards. In the case of
visual warnings, different coloured warning lights could be used as well as a
display indicating the hazard type and ID. Audible warnings could be as
simple as an alarm buzzer or canned speech messages indicating the hazard
type could be employed.
- By comparing past and present ID numbers, units can determine if multiple
hazards of the same type are present and give a different warning than given
for a single hazard of that type.
- Operates basically as an 'ad-hoc' network, no infrastructure required.
- System can handle multiple types of units or hazard types.
- A unit can be set to either accept or ignore messages from certain hazard
types.

Tag or Hazard Types
Fixed Hazard Tag:
- Can be placed on any object or in any area that presents a potential hazard
to
vehicle operators or humans on foot. i.e. an open hole, restricted area,
unsafe
ground.
- Sub-types of the fixed hazard tag are possible as well.
- Acts as a hazard beacon (like a lighthouse)
- Tag could be either be strictly an RF warning or could be accompanied by a
visual or audible warning that is enabled either all the time or when a
vehicle
or human with a tag approaches

Vehicle Tag:
- Tag type used on all mobile equipment
- Sub-types of the vehicle tag are possible as well
- Vehicle tags can be programmed to consider any tag type or sub-type a hazard
or to ignore them
- Each type of detected hazard could produce a unique visual or audible
warning

Human Tag:
- Can be fitted into a safety vest, a belt-pack unit, a hardhat or a miner's
caplamp.
- Human tags can be programmed to consider any tag type or sub-type a hazard
or to ignore them. (i.e. human tags would likely be programmed to ignore
messages from other human tags)


CA 02549870 2006-06-06

- Wearer will be notified of detected hazard visually with a light, audibly
with
an alarm or by way of vibrating the tag unit.

Special Situations
Quiet Zone:
- Unique to vehicle/human situations
- Programmable zone in very close proximity to vehicle in which neither human
nor vehicle operator via vehicle unit is given a warning. The two "ignore" one
another when the signal strength (RSSI)exceeds a certain threshold thus
creating three "zones"; working, hazard and quiet. (See Appendix A)
- Prevents constant warnings given and received by vehicle operators and
passengers.

RFID

Purpose:
Provide time stamped location information for all tag equipped humans,
vehicles or equipment.

How it works:
- Uses same tag hardware as collision avoidance.
- Fixed tag readers placed anywhere that detection of personnel, vehicle or
equipment presence is desired. (i.e. refuge station in an underground mine)
- Collects ID's from units in vicinity of reader.
- Collection range is programmable.
- ID's are collected as the units are transmitting their hazard type and ID
messages three times per second.
- Reader will not receive more than one message at a time due to the anti
message collision protocol used among the tags.
- Once a reader has received a valid ID it can either store the ID and wait to
be
polled by a remote computer or send the information as soon as it's received.
- Fixed readers can be used to trigger events upon detection of certain types
of
units. (i.e. underground ventilation door control, underground ventilation
control based on number and types of vehicles in area, automatically disabling
machinery upon detection of personnel in danger zone)

Dessin représentatif