Measurement agent, a tag, a method for measuring, a method for serving measuring and a computer program product

摘要

A measurement agent for measuring a distance from the agent to a tag may include a transmitter and receiver for transmitting and receiving radio wave signals. The agent is arranged for changing the agent transmitter from a particular state wherein the agent transmitter transmits a particular radio wave interrogation signal towards a further state determined by the agent wherein the agent transmitter transmits a further radio wave interrogation signal when a signal behavior of a received radio wave response signal changes. Further, the measurement agent includes a counter for determining a time period between transmittance of a first radio wave interrogation signal and receipt of a radio wave response signal having a predetermined signal behavior. The agent also includes a processor for computing a distance between the agent and the tag, based on the determined time period and a multiple number of radio wave interrogation signals.

主权项

1. A measurement agent for measuring, in a contactless way, a distance to a tag, the measurement agent comprising:
an agent transmitter for subsequently transmitting a plurality of radio wave interrogation signals to a receiver of the tag, the plurality of radio wave signals having a mutually different signal behavior, a receiver for receiving a radio wave response signal transmitted by a tag transmitter of the tag, a counter, and a processor, wherein:
the measurement agent iteratively changes, upon receiving the radio wave response, the agent transmitter from a first state wherein the agent transmitter transmits a first radio wave interrogation signal having a first spectrum to a second state wherein the agent transmitter transmits a second radio wave interrogation signal having a second spectrum that is different from the first spectrum, such that in each iteration after an initial iteration the first state corresponds to the second state of an immediately preceding iteration,the counter determines a time period starting at a first transmission of the first radio wave interrogation signal and ending upon receipt of the radio wave response signal having a power exceeding a threshold in a pre-determined frequency band, andthe processor has instructions stored which, when executed by the processor, cause the processor to compute a distance between the agent and the tag, the distance being a velocity of light multiplied by the time period and divided by an integrated path number that is equal to a total number of radio wave interrogation signals added to a total number of radio wave response signals.