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 system being configured for:

• during the passing of at least one transponder, exchanging a sequence of first signals between a first transponder coil and said at least one detection antenna and a sequence of second signals between a second transponder coil and said at least one detection antenna;
• 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 on a basis of signal strengths of said first and second signals and said time instances.

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, transmitting via said detection antenna a sequence of first signals to a first transponder coil and receiving a sequence of second signals transmitted by a second transponder coil to said detection antenna, 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 on a basis of the signal strengths of said first and second signals and said time instances.

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, receiving a sequence of first signals transmitted by a first transponder coil and receiving a sequence of second signals transmitted by a 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 on a basis of signal strengths of said first and second signals and said time instances.

A timing module for determining a passing time of moving transponders 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 at least one transponder and said base station;
• and, receiving second signal strength values associated with a sequence of second signals exchanged between at least one transponder and said base station;
• 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 signal strength of said first signals has at least one minimum signal strength value and at least a second time instance T2 at which the signal strength of said second signals has at least one maximum signal strength value;
• determining a passing time Tp by correcting T1 or T2 on a basis of T1 and T2.

A transponder for exchanging signals with a timing system that is configured for determine a passing time when the transponder passes a detection antenna of said timing system, said transponder comprising:

• a detector unit using a first transponder coil for detecting first signals transmitted at a first carrier frequency by the timing system to said transponder;
• a transmitter unit using a second transponder coil for transmitting second signals at a second carrier frequency to the 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;
• and,
• wherein the direction of the magnetic axis of the first transponder coil is different from the direction of the magnetic axis of the second transponder coil.