| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately measure the speed of a moving body to a road surface. <P>SOLUTION: A speed measuring device comprises road surface shape sensors 11a and 11b obtaining road shape data; a memory 12 for storing the road surface shape data; and a computing device 13 for calculating the speed of a vehicle 10 on the basis of the road surface shape data stored in the memory 12. Each of the road surface shape sensors 11a and 11b measures a signal level of each reflection wave reflected by a plurality of structures on the road surface when radiating an electric wave on the road surface, and transmission time since radiating the electric wave till each reflection wave returns, thereby obtaining the road surface shape data. The computing device 13 decides a difference of the measuring time of the road surface shape data when obtaining the road surface shape data related to the road surface shape sensor 11a and the similar road surface shape data related to the road surface shape sensor 11b, and divides a distance between the road surface shape sensors 11a and 11b by the difference of the measuring time to calculate the speed of the vehicle 10. <P>COPYRIGHT: (C)2012,JPO&INPIT |
