Toyota Jidosha Kabushiki Kaisha

Denso Corporation

Nippondenso Co., Ltd.

Hiroshi Naganawa

Hiroshi Mizuno

Hiroto Nakatani

Hiroshi Hazumi

Shinji Ikeda

Akihisa Fujita

Kunihiko Sasaki

Masatoshi Yoneyama

Akihiso Fujita

Receivers 14 and 16 comprise mixers 14b and 16b for mixing reception signals of receiver antennas 14a and 16a with a transmission signal to generate beat signals B1 and B2, respectively. Signal processing section 20 performs the Fourier transformation of beat signals B1 and B2 supplied from receivers 14 and 16 to obtain the phases of beat signals B1 and B2 and then obtain the azimuth based on the difference of these phases.

Radar system for detecting distance, mutual speed and azimuth of a

Beat signals of respective receiver channels CH1 and CH2, produced by mixing their receiving signals with a transmission signal, are subjected to Fourier transformation to detect the frequency and phase of peak frequency components in both an ascending-section where the frequency of the transmission increases and a descending-section where the frequency of the transmission decreases. Based on peak frequency components derived from the same target, phase differences .DELTA..phi.u(i) and .DELTA..phi.d(j) between receiver channels CH1 and CH2 in the ascending- and descending-sections (steps 210-230). Relative relationship between the transmission signal and the receiving signal is judged based on the signs of the phase differences. Respective peak frequencies fu(i) and fd(j), detected as absolute values of frequency differences between the transmission signal and the receiving signal, are given sings in accordance with the judgement result. Then, the distance D and relative velocity V of the target are calculated (steps 240-260).

FMCW radar system for detecting distance, relative velocity and azimuth

An FM-CW radar which is suitable for automotive anti-collision systems, for example, is provided. This radar outputs a radar signal in the form of a triangular wave whose frequency is increased at a given rate and decreased at a given rate. A receiver receives a wave reflected from a target to produce a beat signal and takes the Fourier transform of the beat signal to determine peak frequency components thereof showing peaks in a frequency spectrum. The receiver also determines phases of the peak frequency components and selects at least one from the peak frequency components in a frequency-rising range wherein the frequency of the radar signal is increased and at least one from the peak frequency components in a frequency-falling range wherein the frequency of the radar signal is decreased which show substantially the same phase to pair them for determining the distance to and relative speed of the target based on the frequency of the paired peak frequency components.

FM-CW radar apparatus for measuring relative speed of and distance to an

A Doppler-effect speed detecting apparatus for detecting a ground speed of a motor vehicle, including a transmitter, a receiver for receiving a portion of a wave transmitted by the transmitter and reflected by a road surface, a circuit for detecting an output level of the receiver, and a ground-speed determining device for determining the vehicle ground speed, on the basis of the frequencies of the transmitted and received waves, according to a predetermined first rule when the output level of said receiver is higher than a predetermined threshold value, and according to a predetermined second rule different from the first rule when the output level is not higher than the threshold value.

Doppler-effect vehicle speed sensor using different speed determining

A Doppler-effect speed detecting apparatus for detecting a ground speed of a vehicle, including a transmitter for transmitting a wave towards the ground surface, a receiver for receiving the wave reflected by the ground surface, and an output device for producing an output indicative of the ground speed according to the frequencies of the transmitted and reflected waves. The apparatus further includes a device for determining presence or absence of abnormality relating to the output of the output device, on the basis of an output level of the receiver as well as a speed difference between the ground speed obtained by the output device and an estimated vehicle speed which is obtained on the basis of rotating speeds of the vehicle wheels.

Growing community of inventors

Kagamigahara, Japan

Hiroshi Naganawa