READER SYSTEM FOR WASTE BIN PICKUP
CROSS-REFERENCE TO RELATED 5
The present application is a continuation-in-part of U.S. patent application Ser. No. 08/232,478, filed Apr. 26, 1994, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to improved reader for a radio frequency identification (RFID) tag. More particularly, the present invention relates to an improved reader or 15 reading arrangement mounted on the end of a robot arm, which is disposed on a waste or trash vehicle, for picking up containers or bins of trash waste or the like which are provided with an RFID tag.
It has become increasingly usual in both commercial and residential waste or trash collection for the collector to provide customers with specially designed waste or trash bins which, for collection of the waste or trash, are engaged by a robot arm mounted on a trash or waste vehicle and are 25 lifted vertically to empty the bins into the vehicle or trash truck. The empty bins are then lowered to the ground and returned to the customer. In order for the bins to be engaged and emptied in this manner, it is necessary for the customer to place the bin at a particular location, and preferably with 3Q a particular orientation. In the case of residential customers, this generally entails placing the bin adjacent to the curb on the collection day. In this way, the waste or trash truck can move along the curb and sequentially pickup and empty the bins disposed there for collection. 35
Since the cost of waste or trash collection is often times dependent on the number of containers which are picked up in a given period of time and since, when private trash collection companies are involved, it is possible to have competing trash collection companies which collect trash on 40 the same day, it is necessary to provide some identification on the individual trash bins or containers which identify the person to which the particular bin or container belongs. Although such identification can be visual, it is preferable to provide some kind of identification which can be read 45 automatically so that the time for such identification can be reduced, and thus the efficiency of the trash collection process improved.
One such type of identification which has been provided is an RFID tag attached to the container which identifies the 50 container and thus the customer. Generally this tag is attached to the lid of the container or bin and is readable by a reader mounted on the truck. In one such known reader for this purpose, e.g., utilizing an inductive loop antenna disposed above the container or bin, the range of the reader is 55 very limited so that difficulty in reading the tag results if the bin or container is not properly oriented adjacent to the curb. For example, if the tag is disposed toward the front of the bin or container, but the container is disposed adjacent to the curb so that it is rotated by 180°, whereby the front of the 60 container faces away from the curb, the reading of the tag may not take place since the distance between the tag and the loop may be greater than the read range. This requires that the truck or vehicle operator or driver stop the vehicle and orient the bin or container prior to pickup by the robot arm. 65 Obviously, this results in an increased cost for the collection operation.
Therefore the primary object of the present invention to provide a reader for an RFID tag which can read the tag at larger distances and at various orientations so as to permit the reading of the tag even when the bin is not in the preferred orientation so that the driver may remain in the vehicle.
SUMMARY OF THE INVENTION
The object is generally achieved according to the invention by a reader for a radio frequency identification tag which has at least one magnetic field transmitting and receiving coil oriented in a given plane and which is responsive to a received magnetic exciter field of a first frequency to produce and radiate an identifying magnetic field comprised of a carrier at a second different frequency modulated by an identifying code, with the reader comprising: first means for producing a radio frequency signal of the first frequency; a first magnetic field coupling arrangement connected to the output of the first means for producing a corresponding exciter field at the first frequency to be magnetically coupled to the receiving coil of the tag, with the first magnetic field coupling arrangement including a solenoidal exciter coil having at least one wound exciter winding and a longitudinal axis disposed substantially perpendicular to the plane of the tag coil; a second magnetic field coupling arrangement for receiving a magnetic field of the second frequency produced by the tag and providing a corresponding electrical signal, with the second magnetic field coupling arrangement including at least one receive coil disposed adjacent one end of the solenoidal coil; and, circuitry connected to the at least one receive coil for decoding the received electrical signal.
According to the disclosed embodiment of the invention, at least the exciter and read coils of the reader are mounted on the end of a robot arm which is moveable in at least the vertical direction, the robot arm is mounted on a trash or waste collection type vehicle for at least vertical direction of movement, the axis of the solenoidal exciter coil is substantially vertical, and the robot arm is designed and used for picking up a trash bin or container having a radio frequency identification tag affixed to its lid with the tag coil being substantially horizontal.
According to one embodiment of the invention, the receiver coil is wound around the axis of the solenoidal exciter coil.
However, according to the preferred embodiment of the invention, the receiver coil is disposed along the longitudinal axis of the solenoidal exciter coil and is oriented substantially perpendicular to the solenoidal exciter coil. Still more preferably, a further receiver coil is disposed along the axis of the solenoidal exciter coil at an opposite end of the solenoidal exciter coil from the first receiver coil and is arranged substantially perpendicular to the solenoidal exciter coil, both receiver coils are flat coils, and the two receiver coils are connected in parallel and in phase opposition.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side view showing a waste truck with a robot arm with a reader for engaging and lifting a waste bin provided with an RFID tag.
FIG. 2 is a schematic front view of a trash truck indicating the lifting and dumping of a trash or waste bin as shown in FIG. 1.