Patent ID: 11908319
Assignee: XIDIAN UNIVERSITY
Field: Control (Instruments)
Classification: CPC G | IPC G

Claim 4:
5. The speed measurement method according to claim 1, wherein, in step 5), selecting a reference sensor for the same group of temporal data using the backend processor and creating individual time windows is achieved by the steps of:
5a) processing the first group of temporal data by default using the backend processor, process the second group of data when step 5) is executed again, and so on, setting the geomagnetic sensor with the smallest uploaded temporal data value in the same group of temporal data as the reference sensor for each processing; and
5b) creating individual time windows for the reference sensor based on Eq. [{circumflex over (t)}i, 1−{circumflex over (η)}i, j, {circumflex over (t)}i, 1+{circumflex over (η)}i,j] using the backend processor, and dividing the time difference between the first and last sensor passed by the same group of vehicles into equally spaced time units, where, η
   
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    v, milliseconds and d is the interval between adjacent geomagnetic sensors, and v is the road speed limit value, where {circumflex over ({circumflex over (t)})}i, 1 the measurement time of the i-th geomagnetic sensor in each group the corresponding to the time when the first vehicle passes, and where the i-th geomagnetic sensor is the reference sensor for the j-th geomagnetic sensor.