Abstract: A network including a bus through which data is transmitted and a plurality of network devices connected to the bus to form the network. In the network, at least one of the network devices performs measurement at timings in a predetermined cycle T and outputs data concerning the measurement result on the bus. Another network device detects the cycle T in which the data concerning the measurement result is output, performs measurement at the timings in the predetermined cycle T, and outputs the measurement result on the bus.

Abstract: A radar for detecting a target wherein a standard deviation of the amplitude of a beat signal from a transmission signal and a reception signal is determined for a predetermined period. A threshold is determined by adding a predetermined value to the standard deviation or by multiplying the standard deviation by a predetermined coefficient. The presence or absence of interference on the beat signal is detected according to the presence or the absence of an amplitude greater than the threshold. For example, an amplitude exceeding the standard deviation×2 is considered a spike noise (SPN), i.e., as “presence of interference”. The threshold used for detecting peaks appearing on a frequency spectrum is then increased. This allows detection of the presence or the absence of a spike noise superposed on the beat signal to be performed more certainly, thereby enabling processing according to the presence or the absence of interference.

Abstract: In a radar apparatus, IF beat signals are detected in a first section and a second section serving as two adjacent frequency up-modulation sections of a transmitted wave. Frequency conversions such as FFTs are performed on the IF beat signals so that the frequency spectra are obtained. Subsequently, peak frequencies are detected from the frequency spectra in the corresponding sections, and the phase difference between the peak frequencies is determined. Since the phase difference calculated in this manner depends on the relative moving distance ?r during the interval between the first section and the second section, the relative moving distance ?r, the relative distance, and the relative velocity at this moment can be calculated from the phase difference.

Abstract: A radar apparatus wherein transmission beams are set such that reception intensities corresponding to the transmission beams are gradually reduced from a center direction toward an edge direction of a scanning-angle range. For example, when a vehicle serving as a target is located in the center direction of a transmission beam, the reception-signal intensity corresponding to an adjacent transmission beam is set higher than the reception intensity in the center direction corresponding to the transmission beam. When the scanning-angle distributions of reception-signal intensities corresponding to transmission beams are detected, a scanning angle exhibiting a peak reception-signal intensity is nearer the center of the scanning-angle range than the azimuth angle at which the target is actually located. Thus, a peak reception-signal intensity corresponding to a target located in a region that is a predetermined amount outside the scanning-angle range of a transmission beam appears inside the scanning-angle range.

Abstract: A radar wherein a first threshold value is determined in accordance with the intensity of background noise; second threshold values are set in a fixed frequency area around base portions of peaks in the frequency spectrum; the higher one of these second threshold values is adopted as a decisive threshold value in each FFT bin; and a peak exceeding this threshold value is considered a target peak and detected. Thus, the target peak caused by the reflected wave from a target included in the frequency spectrum of a beat signal is surely detected and detection accuracy of the target is increased.

Abstract: The present invention provides an OCT technique that permits tomographic observation of a biological body parts that is difficult to restrain and also provides a tomographic observation technique for the observation of a constrainable part that does not require constraint and remove the burden from biological body. A wavelength-tunable light generator (wavelength-tunable light source) is employed as the light source of the optical coherence tomography device. The wavelength-tunable light generator has a wave number tunable range width of at least 4.7×10?2 ?m?1 and an emitted-light frequency width of no more than 13 GHz, for example, and includes means capable of changing the wave number stepwise at wave number intervals of no more than 3.1×10?4 ?m?1 and time intervals of no more than 530 ?s.

Abstract: The present invention provides an OCT technique that permits tomographic observation of a biological body parts that is difficult to restrain and also provides a tomographic observation technique for the observation of a constrainable part that does not require constraint and remove the burden from biological body. A wavelength-tunable light generator (wavelength-tunable light source) is employed as the light source of the optical coherence tomography device. The wavelength-tunable light generator has a wave number tunable range width of at least 4.7×10?2 ?m?1 and an emitted-light frequency width of no more than 13 GHz, for example, and includes means capable of changing the wave number stepwise at wave number intervals of no more than 3.1×10?4 ?m?1 and time intervals of no more than 530 ?s.

Abstract: A radar wherein, in accordance with a peak frequency f1[t?nT] of a first projecting portion at a predetermined timing t?nT, a center frequency fr[t] of peak frequencies of first and second projecting portions at a current measurement timing t is predicted, and f1[t] and f2[t] in which (f1[t]+f2[t])/2 approximates the predicted fr[t] is extracted as a pair candidate. In addition, f1[t] and f2[t] in which Doppler shift frequency is substantially equal to a Doppler shift frequency calculated from the peak frequency f1[t?nT] of the first projecting portion and the peak frequency f2[t?nT] of the second projecting portion are selected.

Abstract: A radar wherein, in accordance with a peak frequency f1[t-nT] of a first projecting portion at a predetermined timing t-nT, a center frequency fr[t] of peak frequencies of first and second projecting portions at a current measurement timing t is predicted, and f1[t] and f2[t] in which (f1[t]+f2[t])/2 approximates the predicted fr[t] is extracted as a pair candidate. In addition, f1[t] and f2[t] in which Doppler shift frequency is substantially equal to a Doppler shift frequency calculated from the peak frequency f1[t-nT] of the first projecting portion and the peak frequency f2[t-nT] of the second projecting portion are selected.

Abstract: A radar can detect target azimuths located outside and adjacent to a scanning angular range of a beam by determining changes in received signal strength (a signal-strength profile) in the azimuthal direction as a function of a beam azimuth in a predetermined scanning angular range, and estimating the target azimuth causing the signal-strength profile from the signal-strength profile, which is portion of a convex located adjacent to the outermost angle in the scanning angular range. For example, the target azimuth is estimated by a ratio between the received signal strength at the outermost angle of about 10.0° and the received signal strength at about 9.5°, which is one beam inside the outermost position.

Abstract: A radar including a target measurement component, a differential velocity calculator and an overall velocity determination portion. The target measurement component transmits and receives an electromagnetic wave over a detection range repeatedly at measurement intervals to measure a position of a target in the detection range and measure a Doppler velocity of the target based on a Doppler shift of the electromagnetic wave reflected from the target. The differential velocity calculator determines a differential velocity of the target based on a change in position of the target during consecutive measurement intervals. The overall velocity determination portion determines a current overall velocity by calculating a weighted average of the Doppler velocity, the differential velocity, and a previously determined overall velocity.

Abstract: A radar wherein a first threshold value is determined in accordance with the intensity of background noise; second threshold values are set in a fixed frequency area around base portions of peaks in the frequency spectrum; the higher one in of these second threshold values is adopted as a decisive threshold value in each FFT bin; and a peak exceeding this threshold value is considered as a target peak and detected. Thus, the target peak caused by the reflected wave from a target included in the frequency spectrum of a beat signal is surely detected and detection accuracy of the target is increased.

Abstract: A network including a bus through which data is transmitted and a plurality of network devices connected to the bus to form the network. In the network, at least one of the network devices performs measurement at timings in a predetermined cycle T and outputs data concerning the measurement result on the bus. Another network device detects the cycle T in which the data concerning the measurement result is output, performs measurement at the timings in the predetermined cycle T, and outputs the measurement result on the bus.

Abstract: A radar can detect target azimuths located outside and adjacent to a scanning angular range of a beam determining changes in received signal strength (a signal-strength profile) in the azimuthal direction as a function of a beam azimuth in a predetermined scanning angular range, and estimating the target azimuth causing the signal-strength profile from the signal-strength profile, which is a portion of a convex located adjacent to the outermost angle in the scanning angular range. For example, the target azimuth is estimated by a ratio between the received signal strength at the outermost angle of about 10.0° and the received signal strength at about 9.5°, which is one beam inside the outermost position.

Abstract: An FM-CW radar detects at least one of the relative distance and the relative speed of a predetermined object based on the frequencies of projection portions observed in the frequency spectrums of beat signals in an ascending-modulation section and a descending-modulation section, where the projection portions are generated by one and the same object. The radar determines the moving speed of a predetermined moving object such as a vehicle or the like having the radar mounted thereon, and the frequency difference between the projection portions observed in the frequency spectrums of the beat signals in the ascending-modulation section and the descending-modulation section is inversely calculated, where the frequency difference corresponds to the stationary object, and a predetermined pair corresponding to the frequency difference is extracted on a priority basis.

Abstract: An FM-CW radar detects at least one of the relative distance and the relative speed of a predetermined object based on the frequencies of projection portions observed in the frequency spectrums of beat signals in an ascending-modulation section and a descending-modulation section, where the projection portions are generated by one and the same object. The radar determines the moving speed of a predetermined moving object such as a vehicle or the like having the radar mounted thereon, and the frequency difference between the projection portions observed in the frequency spectrums of the beat signals in the ascending-modulation section and the descending-modulation section is inversely calculated, where the frequency difference corresponds to the stationary object, and a predetermined pair corresponding to the frequency difference is extracted on a priority basis.

Abstract: A radar performs accurate and appropriate pairing even if peaks of approximately identical signal intensities or even if a plurality of peak groups having identical representative beam bearings exist in the frequency spectrum. First, the peak frequency of a peak which appears in the frequency spectrum is determined for each of an up-modulating interval and a down-modulating interval in predetermined beam bearings, and signal-intensity profiles in the beam bearings are extracted with regard to a plurality of beam portions which are adjacent to the beam bearings. Next, the correlation level between the signal-intensity profiles at the up-modulating interval and the down-modulating interval is determined, and pairing is performed in sequence starting from the profiles having a higher correlation level.

Abstract: A radar system achieves adjustment of a time-change characteristic of a frequency-modulating voltage signal to a voltage-controlled oscillator for determining a transmitting signal such that the time-change characteristic of the frequency-modulating voltage signal is changed by a minute amount and the frequency spectrum of a beat signal is determined. The adjustment is performed so that the shape of a bulge in signal intensity included in the frequency spectrum is the sharpest.

Abstract: In a radar, a coupler extracts a part of a transmission signal as a local signal and a mixer mixes a reception signal from a circulator and the local signal so as to output an intermediate frequency signal which is the frequency difference between the transmission signal and the reception signal. An IF-amplifying circuit amplifies the intermediate frequency signal and an AD converter converts the signal to digital data. A DC-removing unit removes a DC component by subtracting the average from the data and an FFT operation unit performs fast Fourier transform so that the distance to a target and the relative velocity of the target are calculated based on a peak included in the frequency spectrum.

Abstract: A radar system and a characteristic adjustment method for the radar system are provided, in which a control voltage waveform of a voltage controlled oscillator for frequency-modulating a sending signal can be set in a short time without increasing the required amount of memory. In adjusting time-varying characteristics of a voltage signal for frequency modulation on a voltage controlled oscillator determining a sending frequency, the time-varying characteristics of the voltage signal for frequency modulation are adjusted to optimize a form of a protrusion in signal intensity included in a frequency spectrum of a beat signal.