Speed measuring apparatus

A speed measuring apparatus comprising:

• transmitting means for transmitting an acoustic reference wave toward a moving-target, said acoustic reference wave being generated based on a reference signal with a predetermined frequency;
• receiving means for receiving acoustic reflection waves which are generated by said transmitted acoustic reference wave being reflected by said moving-target, converting said acoustic reflection waves to receiver signals, and outputting said receiver signals;
• band pass filter means for selectively attenuating a signal component with the same frequency as the frequency of said reference signal, corresponding to the acoustic wave which directly enters said receiving means from said transmitting means by diffraction, and/or the acoustic waves reflected by fixed objects, in said receiver signals which are output from said receiving means and outputting signals therefrom, and for selecting at least one Doppler signal component from said receiver signals output from said receiving means;
• and
• speed computing means for computing the speed of said moving-target relative to said speed measuring apparatus, based on said Doppler signal component selected by said band pass filter means.

A speed measuring apparatus comprising:

• transmitting means for transmitting an acoustic reference wave toward a moving-target, said acoustic reference wave being generated based on a reference signal with a predetermined frequency;
• receiving means for receiving acoustic reflection waves which are generated by said transmitted acoustic reference wave being reflected by said moving-target, converting said acoustic reflection waves to receiver signals, and outputting said receiver signal;
• signal attenuating means for selectively attenuating a signal component with the same frequency as the frequency of said reference signal, corresponding to the acoustic wave which directly enters said receiving means from said transmitting means by diffraction, and/or the acoustic waves reflected by fixed objects, in said receiver signals which are output from said receiving means and outputting signals therefrom;
• analog-to-digital converting means for converting said signals output from said signal attenuating means to digital data, and outputting said digital data;
• and
• digital signal processing means for selecting at least one Doppler signal component from said digital data output from said analog-to-digital converting means and computing the speed of said moving-target relative to said speed measuring apparatus, based on said Doppler signal component selected.

A speed measuring apparatus comprising:

• a transmitter configured to transmit an acoustic reference wave toward a moving-target, said acoustic reference wave being generated based on a reference signal with a predetermined frequency;
• a receiver configured to receive acoustic reflection waves which are generated by said transmitted acoustic reference wave being reflected by said moving-target, to convert said acoustic reflection waves to receiver signals, and to output said receiver signals therefrom;
• a signal attenuator configured to selectively attenuate a signal component with the same frequency as the frequency of said reference signal, corresponding to the acoustic wave which directly enters said receiver from said transmitter by diffraction, and/or the acoustic output signals therefrom;
• at least one band pass filter configured to select at least one Doppler signal component from said signals output from said signal attenuator;
• and
• a speed computing unit configured to compute the speed of said moving-target relative to said speed measuring apparatus, based on said Doppler signal component measured by said at least one band pass filter.

A speed measuring apparatus comprising:

• a transmitter configured to transmit an acoustic reference wave toward a moving-target, said acoustic reference wave being generated based on a reference signal with a predetermined frequency;
• a receiver configured to receive acoustic reflection waves which are generated by said transmitted acoustic reference wave being reflected by said moving-target, to convert said acoustic reflection waves to receiver signals, and to output said receiver signals;
• at least one band pass filter configured to selectively attenuate a signal component with the same frequency as the frequency of said reference signal, corresponding to the acoustic wave which directly enters said receiver from said transmitter by diffraction, and/or the acoustic waves reflected by fixed objects, in said receiver signals which are output from said receiver and to output signals therefrom, and to select at least one Doppler signal component from said receiver signals output from said receiver;
• and
• a speed computing unit configured to compute the speed of said moving-target relative to said speed measuring apparatus, based on said Doppler signal component selected by said at least one band pass filter.

A speed measuring apparatus comprising:

• a transmitter configured to transmit an acoustic reference wave toward a moving-target, said acoustic reference wave being generated based on a reference signal with a predetermined frequency;
• a receiver configured to transmit an acoustic reflection waves which are generated by said transmitted acoustic reference wave being reflected by said moving-target, to convert said acoustic reflection waves to receiver signals, and to output from said receiver and to output signals therefrom;
• an analog-to-digital converting unit configured to convert said signals output from said signal attenuator to digital data, and to output said digital data;
• and
• a digital signal processor configured to select at least on Doppler signal component from said digital data output from said analog-to-digital converting unit and to compute the speed of said moving-target relative to said speed measuring apparatus, based on said measured Doppler signal component.