Operating method and system for predicting collision

Claim 2

An operating method for predicting collision comprising the steps of: transmitting the first wave to a target, receiving said first wave reflected by said target, obtaining a second wave of frequency corresponding to the frequency of said first wave, causing said second wave to interfere with said reflected wave to produce a first beat wave by Doppler effect, changing the frequencies of said first and second waves at the occurance of a specified phase angle of said first beat wave, and detecting at least either one of the polarity and the amount of change of phase of a second beat wave which is generated similarly as said first beat wave according to the frequency variation.

Claim 3

An operating system for predicting collision comprising: means for transmitting a first wave generated by an oscillator to a target, means for receiving a reflected wave reflected by said target, means for branching a part from said first wave generated by said oscillator to obtain a second wave, means for causing said second wave to interfere with said reflected wave to produce a first beat wave by Doppler effect, means for changing the frequencies of said first and second waves generated by said oscillator at the occurance of a specified phase angle of said first beat wave, and means for detecting at least either one of the polarity and the amount of change of phase of a second beat wave generated according to the frequency variation.

Claim 4

An operating system for predicting collision comprising: means for transmitting a first wave generated by an oscillator to a target, means for receiving a reflected wave reflected by said target, means for branching a part from said first wave generated by said oscillator to obtain a second wave, means for causing said second wave to interfere with said reflected wave to produce a first beat wave by Doppler effect, means for changing the frequencies of said first and second waves generated by said oscillator at the occurance of a specified phase angle of said first beat wave, and means for detecting at least either one of the polarity and the amount of change of phase of a second beat wave generated according to the frequency variation.

Claim 5

A vehicle mounted system for detecting impending collision between the vehicle and a target comprising oscillator means for generating a first signal of a predetermined frequency, transmission means for converting said first signal to a first wave and directing said first wave toward a target, receiver means for receiving a reflected wave reflected by the target and converting it to a reflected signal, branching means for branching a part from said first signal generated by said oscillator to obtain a second signal, combining means for causing said second signal to interfere with said reflected signal to produce a first beat signal by Doppler effect, adjustment means responsive to a predetermined phase angle of said first beat signal for altering the predetermined frequency of said oscillator so that modulated first and second signals are formed, said transmission means converting said modulated first signal to a modulated first wave and directing said modulated first wave toward a target and said receiver means receiving a modulated reflected wave and converting it to a modulated reflected signal, said branching means forming a second modulated signal and said combining means causing said second modulated signal to interfere with said reflected modulated signal to form a second beat signal, and detector means for detecting at least either one of the polarity and amount of change of phase of said second beat wave.

Claim 6

A vehicle mounted system for detecting impending collision between the vehicle and a target comprising oscillator means for generating a first signal of a predetermined frequency, transmission means for converting said first signal to a first wave and directing said first wave toward a target, receiver means for receiving a reflected wave reflected by the target and converting it to a reflected signal, branching means for branching a part from said first signal generated by said oscillator to obtain a second signal, combining means for causing said second signal to interfere with said reflected signal to produce a first beat signal by Doppler effect, adjustment means responsive to a predetermined phase angle of said first beat signal for altering the predetermined frequency of said oscillator so that modulated first and second signals are formed, said transmission means converting said modulated first signal to a modulated first wave and directing said modulated first wave toward a target and said receiver means receiving a modulated reflected wave and converting it to a modulated reflected signal, said branching means forming a second modulated signal and said combining means causing said second modulated signal to interfere with said reflected modulated signal to form a second beat signal, and detector means for detecting at least either one of the polarity and amount of change of phase of said second beat wave.

Claim 7

A system in accordance with claim 3 in which said oscillator includes a varactor diode in which said adjustment means comprises means for varying a voltage applied to said varactor diode to thereby vary the frequency output of said oscillator.

Claim 8

A system in accordance with claim 4 in which said means for varying the voltage applied to said varactor diode includes a sawtooth voltage source for varying the voltage applied to the varactor diode in a linear fashion with time to thereby vary the frequency output of said oscillator in a linear fashion with time.