Note: Descriptions are shown in the official language in which they were submitted.
---` 20427~7
This invention relates to automatic weighing,
identification and data recording systems, particularly as
applied to garbage collection.
With an environmental crisis looming and landfill sites
S rapidly filling, a means of prolonging their operational life is
needed. One way is to reduce the amount of waste going to the
landfill site, but this needs the cooperation of the waste
generator, whether industry or the homeowner.
If waste generators were made to pay for the waste they
sent to the landfill on an equitable basis then they would
practice restraint. Weighing and recording the amount of waste
put out by households or other generators is one method of
ensuring that they can be charged based on their use of the
landfill site.
Any method used to weigh waste at the pickup point
must, for economic reasons, be simple to operate and not require
data entry input, such as recording weights or addresses, by the
operator of the waste collection vehicle. No commercially
available method could b~ found which meets the aforementioned
criteria.
The present state of the art of mobile systems of
identification and data collection rely on bar code labels and
reading equipment and require the operator to manually hold a bar
code and scan the container to read the information. Bar code
labels have to be kept clean and intact since it is an optical
reading system. In the hostile environment found in waste
systems, bar code labels would become very difficult if not
impo~sible to read very quickly and would have to be often
replaced. In addition, weather conditions such as rain, ice and
snow would render them almost unreadable. The per~on handling
the bar code reader has to have both hands free and clear which
would mean that gloves and other hand protection could not be
worn when using the device. After much thought about how to
overcome the limitations o~ present systems the following system
was conceived.
In the invention, an electronic transmitter-identity
tag, i.e. a radio frequency tag (RF tag), is either affixed to
.,, , . - ,. ..
". '" ' ; ' ' ', . ": ' . ,
,
4L27~7
a waste receptacle or secured in the proximity of a waste pickup
point. The RF tag contains a microprocessor with a permanent
memory so that identification data can be programmed into it to
identify the source of the waste. The RF tag also contains a
radio transmitting system and a long wave radio receiver. The
RF tag is battery-powered, and sealed in such a way that it is
protected from the elements, environmental contaminants, and
physical damage.
The invention also includes an electronic device,
hereinafter referred to as a RF reader, which includes a
microprocessor controlled radio frequency transmitter and a ~-
microprocessor controlled radio frequency receiver. The RF
reader is mounted on a waste collection vehicle.
During waste collection operations, the RF reader sends
a radio signal operating at a suitable radio frequency such as
135 kHz. When the RF reader comes within range of a RF tag, the
long range signal is received by the RF tag and the RF tag's
transmitter is activated. on activation, the RF tag radio
transmits its stored identification data/ and the radio signal
encoding this data is received and the identification data is
captured by the RF reader. The microprocessor of the RF tag can
be programmed remotely by the RF xeader, to store an
identification code.
~he invention further includes a weighing device, such
as a strain gauge type load cell, mounted on the hoist-dump
device and connected by an electrical cable to a computer. On
picking up the load (i.e. the waste), the strain gauge is
deflected and an electrical signal is attenuated. A
microprocessor incorporated in the scale converts the analog
signal to digital and transmits it to the computer.
The computer receives and stores signals received from
both the RF reader (i.e. the identi~ication data) and the
weighing device (i.e. the weight data). The invention includes
computer software to receive the signals and process them so that
the weight of the waste picked up can be ma~ched with its source.
The system does not require line-of-sight between the
RF reader and RF tag for reliable operation. Identification
: . . ., , : .. :-
.. ,", ,. , , ., , . . :~
. . . :, . . . . . .
., " ~:~ "
,,
. .
--" 2~1~27~7
performance is unimpaired by dirt, oil, and other environmental
contaminants. The system has been designed to o~fer flexibility
of operation, and can provide truly automatic identification of
all manner of objects, by attachment of a small electronic RF tag
thereto.
Preferably, the RF reader has output ports which allow
it to be connected as a direct replacement for industry standard
magnetic card or bar code readers, making the integration of the
system into existing identification and data capture systems a
straightforward exercise. Key features of the preferred
embodiment of the invention are:
High speed data transfer from RF tag to RF reader
Simultaneous identification of numerous RF tags by one
RF reader
RF tags are reprogrammable ln situ by a RF reader, using
modulated radio signals
A RF tag can store 256 bits of user-specified data
A RF tag may encrypt stored data before transmission
Flexibility of RF reader operation, configured through
resident firmware
Output ports on the RF reader compatible with industry
standard card readers and bar code readers
Ease of installation
Automatic operation
Further features of the invention will be described or
will become apparent in the course of the following detailed ~-
description. -
In order that the invention may be more clearly
understood, the preferred embodiment thereof will now be
described by way of example only, with reference to the ~ ;
accompanying drawings, in which:
Fig. 1 is a drawing of one version of the invention;
and
Fig. 2 is a drawing of a variation of the invention.
The system has four main components, namely, a RF tag
1 and a RF reader 2, which in combination form an electronic
identification system providing a means of remotely identifying
- 4 -
' ' . ',' . ' , '~ " ,~ , ' ;", '''' ' ` ' '''
~: ~ ,, ''' , ;'
. : , , .. , ., ,; : . -, ; ; ,
, . . . . . . .
~ ~4~7~ 7
the source of the waste; a weighing device 3, and computer 4 and
software capable of receiving signals from the RF reader and the
weighing device, encoding identification data and weight data,
and processing the date so that the weight of the waste picked
up can be matched with the identity of its source.
The RF tag is a miniature radio ~re~uency receiver and
transmitter, controlled by a custom-designed integrated circuit
which is programmable by an operator remote from the RF tag,
powered by a long-life lithium cell~ and sealed in a small
plastic case to protect the contents from the elements,
environmental contaminants, and physical damage.
In the preferred embodiment, the ~F tag and reader are
of the type supplied by DISYS IncO of Toronto, Ontario, Canada,
or DISYS Limited of Burnham, Buckinghamshire, En~land, as their
15 ll90 Series Automatic Identification System'l. The RF tag has an
operating temperature range from -20~C to 70C, and may be stored
safely over a storage temperature range extending from -20~C to
40C. It is powered by a long life lithium battery, and in use
has a "life expectancy" typically greater than five years.
Preferably, the RF tag is provided with means to transmit a low
battery warning. Each RF tag has a data capacity of 256 bits,
formatted as 32 eight-bit blocks~ From one to thirty-two blocks
may be transmitted in any given transmission. The "data reading
rate" ranges from 4,800 to 38,400 bits per second (bps). The
"programming data ratP" is typically 1,200 bps.
Hence, at each waste pickup point, a RF tag storing
programmed data identifying the waste generator may either be
attached to a waste receptacle S containing waste to be picked
up (as shown in Fig. 2), or be placed on a structure 6 in the
proximity of the waste pickup point (as shown in Fig. 1).
Alternatively, the RF tag may be buried in the ground in the
proximity of the road or laneway travelled by the wasta
collection vehicle.
The RF reader includes a microprocessor controlled
radio frequency transmitter (i.e. the transmit antenna) and a
microprocessor controlled radio frequency receiver, which
transmits selected radio signals to the RF tag. The RF reader
-- 5 --
.
- . . .
20~27~ 7
has a sealed plastic case, and operating temperature ranges from
-20 C to 50 C. Its storage temperature range extends from -40 C
to 85 C.
The RF reader is mounted either on a waste collection
vehicle or on a hoist-dump device used to place the waste picXed
up on the vehicle. The RF reader must be placed so that the RF
reader's transmitting device is able to efficiently communicate
its signal to the RF tag's receiver device, and similarly receive
radio signals therefrom. The RF reader is mounted on the waste
collection vehicle, within the RF tag's interrogation range, so
that it can transmit signals to the RF tag by radio waves, and
similarly receive radio signals therefrom.
The RF reader is powered from an external power source.
To operate, the RF reader requires a power input of from 15 to
28V DC or AC (RMS). The current is less than 60mA when the RF
reader is inactive, and less than 200mA when active.
When the waste collection vehicle enters the proximity
of a first waste collection pickup point, the RF reader's long
wave signal is received by the RF tag storing identification data
for that address, a~d the RF tag's radio transmitter is activated
by the RF reader's radio signal~ The RF tag's transmitter
typically operates at a frequency of 417 mHz. Upon r~ceipt of
the radio signal transmitted by the RF reader, the RF tag is
activated and then transmits a radio signal encoding the ~F tag's
stored data, thereby transferring, at high speed, data for
identi~ication of the waste generator which is captured by the
RF reader 2.
Upon receipt of the identification code transmitted
by the RF tag, the RF reader decodes, then transmits the captured
identi~ication data to a monitoring computer which is connected
to the RF reader by an electrical cable. The RF reader has an
asynchronous serial port that transmits data at a data rate of
300 to 9,600 baud; and has a frame length of 7 or 8 data bits;
parity optional.
To facilitate integration of the identification and
data capture system of the invention into existing identification
and data capture system, the RF reader preferably has a card
-- 6 --
. :~ . . . .
,. ", , ~ . ', ' ~ ' ,; , : ~: "' ,
.
: ~ , , . , , : , . . .
---`` 20~2 ~7
reader output port, compatible with industry standard Wiegand
card reader heads and magnetic stripe readers, and also, a bar
code output port, compatible with industry standard wands and
scanners, which allow the RF reader to be connected as a direct
replacement for industry standard magnetic card or bar code
readers. The RF reader's bar code output port supports the
following symbologies: Code 128, Code 39, Code 93, Codabar,
Interleaved 2 of 5, and UPC/EANo
The RF reader has powerful programmable features which
allow its mode of operation to be tailored to suit many and
varied applications with ease. The identification system does
not require line-of-sight between RF reader and RF tag for
reliable operation, and identification performance is unimpaired
by dirt, oil and other environmental contaminants. The
microprocessor of the RF tag can be programmed remotely by the
RF reader, to store an identification code which can be
transmitted to the ~F reader.
A third component of this invention is a weighing
device 3 which is preferably secured to the waste collection
vehicle~s hoist-dump device, and is connected to a fourth
component 4 of electronic circuitry an~ computer software by a
cable. The preferred embodiment of the invention has an
electronic load cell of a strain gauge type which is used for
weighing purposes. The weigh scale is of either the compression
or tension type depending on how it is mounted. To maintain
accuracy, the weighing of the load should be carried out a~ter
movement of the scale has stopped.
On picking up and receiving the load (i.e. the waste),
the strain gauge is deflected and an electrical signal is
aktenuated. With this type o~ scale, the resistance of an
electrically balanced resistance "bridge" varies with the weight
of a load placed upon a mechanical frame forming part of the
weighing platform of the scale. The change in resistance caused
by the distortion of the frame holding the resistance bridge is
proportional to the weight placed upon the frame.
In the preferred embodiment, the electrical output from
the load cell (providing the weight of the load weighed) can be
,:. . .... . . . . :: .
,- - , , ~ , ~ , . -
: . . , . ,: . . :
~ 2~27~ ~
conditioned using the electronic circuitry and computer software
comprising the fourth main component of this invention 4 to
receive the signals transmitted by the RF tag and the strain
gauge weighing device, respectively, and then process them so
that the weight of the waste picked up can be matched with its
source. The data can either be used to produce a direct display
read out, or be converted to a serial ASCII signal and thence
input to a computer via a serial port connector.
The computer receives and stores the identification and
weight data received from the ~F reader and the weighing device,
respectively, using a suitable software program. Typically, the
data are stored in data files using ASCII format, and, if
required, may be printed upon command to provide hard copy. The
captured identification and weight data, using either computer
hardware or software or combinations thereof, can be processed
further for storage by electronic means such as a RAM chip or
floppy or hard disk storage or other suitable means.
At some suitable time, the information stored in the
computer can be "dumped" or transferred to a billing computer for
charging the customer for the waste picked up.
It will be appreciated that the above description
refers to embodiments by way of example only. The principle of
the invention may have other applications, many of which will be
obvious to those knowledgeable in the fi~eld.
For example, a similar system to the above could be
used to remotely and automatically record the weight o~ trucks
on highways. In this instance, the weighing device is installed
as part of a scale and the identifying RF tag is mounted on the
truck. The RF reader is mounted at a point where the RF tagged
truck passing over the weighing device can send the signal as it
drives past. As with the previously described invention, there
is no operator intervention necessary to weigh and record the
identification of the loaded materialO The daka stored in the
computer may be retrieved directly from the computer RAM or be
subjected to further processing and analyses using computer
hardware or software, or combinations thereof.
- 8 -
-,: ' ,-' ,,' ' ',: . ' ~ , ~,
.- , ' . ' ' :,, .: ,, ., '
