PURPOSE: To improve the detection precision by receiving reflected waves of two microwaves whose directions of polarization are orthogonal to each other and adding respective reception signals and detecting a vehicle based on the variance in level of the addition output.
CONSTITUTION: Reflected waves of transmission waves transmitted from transmission antennas 5a and 5b are received by an antenna 6 and are supplied to logarithmic conversion amplifiers 85 and 86 through a detector 82 and sampling and holding circuits 83 and 84. Respective amplification outputs are different in signal level variance, and these signals are added by an adder 87 to compensate the level variance of one reception signal with that of the other. A level discriminator 88 compares the addition output with a preliminarily set threshold to discriminate the frequency in excess over the threshold as the number of vehicles.
JP2743414 | [Title of Invention] Congestion Recognition Device |
WO/2019/121521 | METHOD AND DEVICE |
WO/2021/064899 | LEARNING DEVICE, PREDICTION DEVICE, LEARNING METHOD, AND LEARNING PROGRAM |
KAMEMURA AKIHIRO
IWAI TORU
OOMI NORICHIKA