Determining the passing time of a moving transponder

A timing system for determining a passing time of moving transponders passing at least one detection antenna of a base station, said timing system being configured for:

• during the passing of at least one transponder, the at least one transponder comprising a first transponder coil and a second transponder coil, exchanging a sequence of first signals between the first transponder coil and said at least one detection antenna and a sequence of second signals between the second transponder coil and said at least one detection antenna wherein a direction of a magnetic axis of said first transponder coil differs from a direction of a magnetic axis of said second transponder coil;
• associating said first and/or second signals with time instances indicating a time when said first and/or second signals are exchanged between said at least one transponder and said base station;
• and,
• determining the passing time of said at least one transponder with respect to the detection antenna on a basis of applying a correction based on a time difference of selected characteristics occurring in the signal strengths of said first and second signals as the first and second transponder coils pass by the detection antenna.

A base station for determining a passing time of moving transponders passing a detection antenna, said base station being configured for:

• during the passing of at least one transponder, the at least one transponder comprising a first transponder coil and a second transponder coil, transmitting via said detection antenna a sequence of first signals to the first transponder coil and receiving a sequence of second signals transmitted by the second transponder coil to said detection antenna, wherein a direction of a magnetic axis of said first transponder coil differs from a direction of a magnetic axis of said second transponder coil, said second signals comprising signal strength values of said first signals;
• associating said first and/or second signals with time instances indicating a time when said first and/or second signals are exchanged between said at least one transponder and said base station;
• and,
• determining the passing time of said at least one transponder with respect to the detection antenna on a basis applying a correction based on a time difference of selected characteristics occurring in the of the signal strengths of said first and second signals as the first and second transponder coils pass by the detection antenna.

A base station for determining a passing time of moving transponders passing a detection antenna, said base station being configured for:

• during the passing of at least one transponder, the at least one transponder comprising a first transponder coil and a second transponder coil, receiving a sequence of first signals transmitted by the first transponder coil and receiving a sequence of second signals transmitted by the second transponder coil, wherein a direction of a magnetic axis of said first transponder coil differs from a direction of a magnetic axis of said second transponder coil;
• associating said first and/or second signals with time instances indicating a time when said first and/or second signals are exchanged between said transponder and said base station;
• and,
• determining the passing time of said transponder with respect to the detection antenna on a basis of applying a correction based on a time difference of selected characteristics occurring in the signal strengths of said first and second signals as the first and second transponder coils pass by the detection antenna.

A timing module for determining a passing time of a moving transponder passing a detection antenna of a base station, said module being configured for:

• receiving first signal strength values associated with a sequence of first signals exchanged between a first transponder coil of the transponder and said base station;
• and, receiving second signal strength values associated with a sequence of second signals exchanged between a second transponder coil of the transponder and said base station, wherein a direction of a magnetic axis of said first transponder coil differs from a direction of a magnetic axis of said second transponder coil;
• wherein said first and second strength values are associated with time instances at which said first and/or second signals are exchanged between said transponder and said base station;
• determining at least a first time instance T1 at which the first signal strength values associated with said first signals exchanged between the first transponder coil and the detection antenna has at least one minimum signal strength value and at least a second time instance T2 at which the second signal strength values associated with said second signals exchanged between the second transponder coil and the detection antenna has at least one maximum signal strength value;
• and,
• determining a passing time Tp of said transponder with respect to the detection antenna by correcting T1 or T2 on a basis of based on a time difference between T1 and T2.