Shima Seiki Manufacturing Limited

The University of Tokushima

Nohken Inc.

Tadamitsu Iritani

Tetsuji Uebo

Kazuhiro Wakabayashi

A transmission unit emits an electromagnetic wave having the same frequency f as an output signal from a sending unit in a direction of a measurement axis. A detecting unit performs synchronous detection on a reflected wave detected by a directional coupler by an in-phase signal and a quadrature signal of the transmission signal, and by extracting DC component from the detection signal, detects the in-phase component and quadrature component of the reflected wave. An analysis signal generating unit mixes the in-phase component and quadrature component of the reflected wave and signals having periodicity corresponding to a prescribed distance, and using only one of the resulting side bands, generates an analysis signal. Fourier transform unit finds distance to the object of measurement from a profile obtained by Fourier transform of the analysis signal.

Distance measuring device, distance measuring method and distance measuring program

A distance can be measured with high resolution. A frequency controller () controls a voltage control oscillator () so as to change a signal source frequency f in a range containing two center frequencies fand fand transmits it as a traveling wave from an antenna () to a target (). A reflected wave reflected by the target () and the traveling wave interfere each other and form a standing wave. A power detector () detects power corresponding to the amplitude of the standing wave and performs Fourier transform based on the two center frequencies fand fin Fourier transform means (), respectively, thereby calculating radar image functions P(x), P(x). The distance d to the target () satisfies the conditions that the phase difference of the two radar image functions zero-crosses and the amplitude of the radar image functions becomes maximum. The zero cross point of the phase difference is a zero cross point of a linear function and can be identified with high resolution.

Growing community of inventors

Tokushima, Japan

Tadamitsu Iritani