Method and System for Mitigating Metallic Vibration or Shaking Effects in Proximity of a RFID Reader

A method of detecting objects having an RFID tag with an RFID reader, the RFID reader having an antenna loop, the antenna loop defining an opening to allow passage of the objects, the antenna loop being positioned in an environment having a metallic structure that is shakable with respect to the antenna loop, the method comprising:

• determining a first current level for the antenna loop that allows detection of the RFID tag when the metallic structure is not shaking but that does not allow detection of the RFID tag as at least one of the objects passes through the opening when the metallic structure is shaking;
• establishing a second current level that is lower than the first current level for the antenna loop and that allows detection of the RFID tag as at least one of the objects passes through the opening when the metallic structure is shaking or not shaking;
• setting an operating current of the antenna loop, according to the established second current;
• producing an electromagnetic wave with the antenna loop set at the operating current;
• passing an RFID tagged object through the opening;
• shaking the metallic structure;
• and
• detecting an RFID tagged object during the shaking by powering the RFID tag of the tagged object with the electromagnetic wave and receiving a response wave produced by the powered RFID tag.

An RFID reader system comprising:

• an antenna loop defining a reduced passage region according to an item having an RFID tag in order to still allow the item to pass there through;
• a controller connected to the antenna loop, the controller being adapted to control a current of the antenna loop in order to produce a controlled electromagnetic field within the reduced passage region and limit propagation of residual electromagnetic field outside the reduced passage region to prevent inducing a current that is strong enough within a surrounding shaking metallic structure such as to produce electromagnetic waves capable of interfering with a response wave produced by the RFID tag as it is passing through the reduced passage region;
• and
• a receiver adapted to receive the response wave produced by the RFID tag as it is passing through the reduced passage region.