Speed detecting device employing a Doppler radar

Claim 2

A speed detecting device having converting means for converting a Doppler signal obtained from a Doppler radar into a corresponding speed indicating signal, comprising: reference signal setting means for setting a reference amplitude value; amplitude detecting means for detecting the amplitude of said Doppler signal; comparing means for comparing said reference amplitude value with the detected amplitude of said Doppler signal in order to identify as a comparison result those portions of said Doppler signal which are detected to be smaller in amplitude than said reference amplitude value; and excluding means for excluding from said speed indicating signal corresponding to said Doppler signal those portions of said Doppler signal which are identified as said comparison result; and wherein said setting means includes means for setting said reference amplitude value based on the relationship between a amplitude of the Doppler signal and the variance of a speed detection error.

Claim 3

The speed detecting device as defined in claim 1, wherein said excluding means includes means for outputting the speed indicating signal which is present immediately before the amplitude of said Doppler signal falls below said reference amplitude value when the amplitude of said Doppler signal is below said reference amplitude value.

Claim 4

The speed detecting device as defined in claim 1 wherein said converting means for converting said Doppler signal to said speed indicating signal is a frequency-to-voltage converter.

Claim 5

A speed detecting device having converting means for converting a Doppler signal obtained from a Doppler radar into a corresponding speed indicating signal comprising: reference signal setting means for setting a reference amplitude value; amplitude detecting means for detecting the amplitude of said Doppler signal; and arithmetic operation means for outputting a modified speed indicating signal V i * at time i in accordance with the following equation: ##EQU26## where: A o is equal to said reference amplitude value, A i is equal to said amplitude of said Doppler signal at time i, V i is equal to said speed indicating signal at time i, and V*.sub.(i-1) is equal to said modified speed indicating signal at an earlier time i-1; wherein said reference signal setting means includes means for setting said reference amplitude value A o in accordance with the following equation: ##EQU27##

Claim 6

A speed detecting device having converting means for converting a Doppler signal obtained from a Doppler radar into a corresponding speed indicating signal comprising: reference signal setting means for setting a reference amplitude value; amplitude detecting means for detecting the amplitude of said Doppler signal; and arithmetic operation means for outputting a modified speed indicating signal V i * at time i in accordance with the following equation: ##EQU26## where: A o is equal to said reference amplitude value, A i is equal to said amplitude of said Doppler signal at time i, V i is equal to said speed indicating signal at time i, and V*.sub.(i-1) is equal to said modified speed indicating signal at an earlier time i-1; wherein said reference signal setting means includes means for setting said reference amplitude value A o in accordance with the following equation: ##EQU27##

Claim 7

A speed detecting signal comprising: a plurality of Doppler radars for generating a corresponding plurality of Doppler signals; amplitude detecting means for detecting and comparing the amplitude of each one of said plurality of Doppler signals to the amplitude of other ones of said plurality of Doppler signals; selection means for selecting and outputting the Doppler signal having the largest amplitude found as a result of said comparison of the amplitude values detected and compared by said amplitude detecting means; reference signal setting means for setting a reference amplitude value for each of said Doppler signals; comparing means for comparing each of said Doppler signals with a corresponding one of said reference amplitude values in order to identify as a comparison result those portions of said detected Doppler signals which are in amplitude smaller than said reference amplitude value; converting means for converting each of said Doppler signals into a corresponding speed indicating signal; and excluding means for excluding from each of said Doppler signals converted by said converting means into a corresponding speed indicating signal those portions of said Doppler signals which are identified as said comparison result; wherein said setting means includes means for setting each of said reference amplitude values based on a relationship between the corresponding amplitude value of each of said Doppler signals and a variance of the speed detection error.

Claim 8

A speed detecting signal comprising: a plurality of Doppler radars for generating a corresponding plurality of Doppler signals; amplitude detecting means for detecting and comparing the amplitude of each one of said plurality of Doppler signals to the amplitude of other ones of said plurality of Doppler signals; selection means for selecting and outputting the Doppler signal having the largest amplitude found as a result of said comparison of the amplitude values detected and compared by said amplitude detecting means; reference signal setting means for setting a reference amplitude value for each of said Doppler signals; comparing means for comparing each of said Doppler signals with a corresponding one of said reference amplitude values in order to identify as a comparison result those portions of said detected Doppler signals which are in amplitude smaller than said reference amplitude value; converting means for converting each of said Doppler signals into a corresponding speed indicating signal; and excluding means for excluding from each of said Doppler signals converted by said converting means into a corresponding speed indicating signal those portions of said Doppler signals which are identified as said comparison result; wherein said setting means includes means for setting each of said reference amplitude values based on a relationship between the corresponding amplitude value of each of said Doppler signals and a variance of the speed detection error.

Claim 9

The speed detecting device as defined in claim 5, wherein said excluding means includes means for outputting the speed indicating signal which is present immediately before the amplitude of said corresponding Doppler signal falls below said reference amplitude value upon such times as the amplitude of said Doppler signal is below said reference amplitude value.

Claim 10

A speed detecting means comprising: a plurality of Doppler radars for generating a corresponding plurality of Doppler signals; amplitude detecting means for detecting the amplitudes of said Doppler signals obtained from said plurality of Doppler radars; converting means for converting each of said Doppler signals into a corresponding speed indicating signal; and arithmetic computational means for obtaining the weighted arithmetic mean of said speed indicating signals corresponding to said Doppler signals using the amplitude value detected by said amplitude detecting means as the weighting factor; reference signal setting means for setting a reference amplitude value for each of said Doppler signals; comparing means for comparing each of said Doppler signals detected amplitudes with said corresponding reference amplitude values in order to identify as a comparison result those portions of said detected Doppler signals amplitudes which are smaller than said reference amplitude value; and excluding means for excluding from said speed indicating signals corresponding to said Doppler signals those portions of said Doppler signals which are identified as said comparison result; wherein said setting means includes means for setting said reference amplitude value based on a relationship between the amplitude value of the Doppler signal and a variance of speed detection error.

Claim 11

A speed detecting means comprising: a plurality of Doppler radars for generating a corresponding plurality of Doppler signals; amplitude detecting means for detecting the amplitudes of said Doppler signals obtained from said plurality of Doppler radars; converting means for converting each of said Doppler signals into a corresponding speed indicating signal; and arithmetic computational means for obtaining the weighted arithmetic mean of said speed indicating signals corresponding to said Doppler signals using the amplitude value detected by said amplitude detecting means as the weighting factor; reference signal setting means for setting a reference amplitude value for each of said Doppler signals; comparing means for comparing each of said Doppler signals detected amplitudes with said corresponding reference amplitude values in order to identify as a comparison result those portions of said detected Doppler signals amplitudes which are smaller than said reference amplitude value; and excluding means for excluding from said speed indicating signals corresponding to said Doppler signals those portions of said Doppler signals which are identified as said comparison result; wherein said setting means includes means for setting said reference amplitude value based on a relationship between the amplitude value of the Doppler signal and a variance of speed detection error.

Claim 12

The speed detecting device as defined in claim 7 wherein said excluding means includes means for outputting the speed indicating signal which is present immediately before the amplitude of said Doppler signal falls below said reference amplitude value upon such times as the amplitude of said Doppler signal is below said reference amplitude value.

Claim 13

The speed detecting device as defined in claim 7 wherein said converting means for converting said Doppler signal to said speed indicating signal is a frequency-to-voltage converter.

Claim 14

A speed detecting device having converting means for converting a Doppler signal obtained from a Doppler radar into a corresponding speed indicating signal, comprising: a variable frequency oscillator for generating a variable frequency signal; a modulation generator for changing the oscillation frequency of said variable frequency oscillator in a periodic sequence; detecting means for detecting said Doppler signal in synchronization with the modulation period of said modulation generator; signal processing means for forming from said Doppler signal a plurality of modified Doppler signals corresponding to said plurality of frequencies based on the output signal of said detecting means, and for forming from said Doppler signal a plurality of amplitude signals corresponding to said plurality of frequencies; arithmetic computational means for selecting as an output signal the modified Doppler signal corresponding to that amplitude signal having the largest amplitude of all amplitude signals formed by said signal processing means; reference signal setting means for presetting a reference amplitude value for each of said plurality of modified Doppler signals obtained by said signal processing means; comparing means for comparing each of said modified Doppler signals with said corresponding reference amplitude values in order to identify as a comparison result those portions of said modified Doppler signals which are in amplitude smaller than a corresponding said reference amplitude value; converting means for converting each of said modified Doppler signals to a corresponding speed indicating signal; and excluding means for excluding from each said modified Doppler signals converted by said converting means into said speed indicating signals those portions of said modified Doppler signals which are identified as said comparison result; wherein said setting means include means for setting said reference amplitude value based on a relationship between the amplitude value of said Doppler signal and a variance of the speed detection error.

Claim 15

A speed detecting device having converting means for converting a Doppler signal obtained from a Doppler radar into a corresponding speed indicating signal, comprising: a variable frequency oscillator for generating a variable frequency signal; a modulation generator for changing the oscillation frequency of said variable frequency oscillator in a periodic sequence; detecting means for detecting said Doppler signal in synchronization with the modulation period of said modulation generator; signal processing means for forming from said Doppler signal a plurality of modified Doppler signals corresponding to said plurality of frequencies based on the output signal of said detecting means, and for forming from said Doppler signal a plurality of amplitude signals corresponding to said plurality of frequencies; arithmetic computational means for selecting as an output signal the modified Doppler signal corresponding to that amplitude signal having the largest amplitude of all amplitude signals formed by said signal processing means; reference signal setting means for presetting a reference amplitude value for each of said plurality of modified Doppler signals obtained by said signal processing means; comparing means for comparing each of said modified Doppler signals with said corresponding reference amplitude values in order to identify as a comparison result those portions of said modified Doppler signals which are in amplitude smaller than a corresponding said reference amplitude value; converting means for converting each of said modified Doppler signals to a corresponding speed indicating signal; and excluding means for excluding from each said modified Doppler signals converted by said converting means into said speed indicating signals those portions of said modified Doppler signals which are identified as said comparison result; wherein said setting means include means for setting said reference amplitude value based on a relationship between the amplitude value of said Doppler signal and a variance of the speed detection error.

Claim 16

The speed detecting device as defined in claim 10, wherein said excluding means includes means for outputting the speed indicating signal which is present immediately before the amplitude of said Doppler signal falls below said reference amplitude value upon such times as the amplitude of said Doppler signal is below said reference amplitude value.

Claim 17

The speed detecting device as defined in claim 10 wherein said converting means for converting said Doppler signal to said speed indicating signal is a frequency-to-voltage converter.