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

Claim 3:
4. The speed measurement method according to claim 1, wherein, in step 3) the data cleaning of the received temporal data using the backend processor is achieved by the steps of:
3a) setting an upper data limit threshold Th3, a lower data limit thresholds Th4 and a data increase threshold Th using the backend processor 4 to so that when the data reported by the geomagnetic sensor is higher the upper data limit threshold Th3 or lower than the lower data limit threshold Th4, the data is discarded, thus removing the data that is clearly abnormal; the data increase threshold Th is a ratio of an adjacent sensor distance to the road speed limit; the upper data limit threshold Th3 is the last temporal data in the set; and the lower data limit threshold Th4 is the first temporal data in the data set; and
3b) processing each of the two adjacent temporal data using the backend processor, and determining that there is a case of detecting one vehicle as multiple vehicles at that point when the latter data is lower than the former data plus the data increase threshold Th, and removing the latter of the two adjacent data.