Fujitsu Corporation

Fujitsu Ten Limited

Satoshi Ishii

Yoshikazu Dooi

Hiroyuki Yatsuka

Tetsuo Seki

Kazuaki Hamada

Masayuki Kishida

Nobukazu Shima

Kenji Oka

Masaki Hitotsuya

Sadanori Matsui

Akihiro Ohta

Masayoshi Moriya

In order to provide the method and the device for distance measurement by pulse radar that securely eliminates the false echo from the distance over the detectable limit determined by the pulse generation cycle, the pulse radar comprises the pulse signal sending unit that generates the pulse signals with different cycles at OSC, switches to the predetermined intervals by OSC switch, and sends the pulse signal to targets, the reflected signal receiving unit that receives the reflected signals and stores the data in the RAM, the reflected signal data acquisition unit that obtains the data of each reflected signal, and the reflected signal identification unit that compares the intensity of the reflected signals obtained at the same lag time point during a certain time period after sending the pulse signal for reference and identifies the reflected signals of the sent pulse signal for reference.

Method and device for distance measurement by pulse radar

A radar apparatus comprises: a transmitter unit having a high-frequency oscillating unit whose oscillation frequency is variable, and a pulse amplitude modulating unit for amplitude-modulating a pulse of a transmission high-frequency signal output from the high-frequency oscillating unit with a first control pulse signal; a receiver unit having a gating unit for controlling ON/OFF of an input of a received high-frequency signal with a second control pulse signal; and a controlling and signal processing unit for controlling the transmitter unit and the receiver unit, and for switching a first operation mode for making the apparatus function as an FM-CW radar, and a second operation mode for making the apparatus function as a pulse radar.

Radar apparatus, radar apparatus controlling method

A pulse radar apparatus uses different frequencies, for example, frequencies one of which is a multiple or a submultiple of the other for a signal which becomes a reference of a control pulse for controlling a gate operation for a reception signal and a signal which becomes a base of generation of a transmission pulse. As a result, even if noise is caused by the gate operation, its influence can be removed in the processing of reception signals having different frequencies.

Pulse radar apparatus

An embodiment comprises a unit generating a control pulse signal by delaying a basic signal in generating a transmission pulse, and a unit performing a gate operation on a received signal using the control pulse signal. Another embodiment comprises a unit generating a control pulse signal by delaying a signal generated using a first basic signal, a second signal for phase modulation having a lower frequency than the first signal, and a pseudo-random signal generated at an intermediate frequency between the frequencies of the first and second signals, and a unit performing the gate operation.

A signal from CW radar is received, and the received power detected by the CW radar's swinging in all directions is averaged in each direction. Then, the maximum value and the minimum value of the received power are detected for each direction, and the difference between the maximum value and the minimum value is computed. An average power value of obtained power is also computed. On a 2-dimensional plane on which the difference between the maximum value and the minimum value and the average power value are used for coordinate axes, slice processing is performed using a threshold indicated by a line graph or a curve.

Signal processing apparatus of radio radar

The crossover detection method of a radar apparatus according to the present invention calculates distance/relative velocity information at a multitude of different clock times, using a beat signal; calculates predicted distance/relative velocity information indicating distance/relative velocity, respectively, of a target after a prescribed time has elapsed; calculates predicted distance/relative velocity errors by subtracting the calculated distance/relative velocity information from the calculated predicted distance/relative velocity information, respectively; calculates degree of similarity information, based on the predetermined average predicted distance/relative velocity errors and the calculated predicted distance/relative velocity errors; and determines whether there is crossover, based on the above information.

Growing community of inventors

Kawasaki, Japan

Satoshi Ishii